Encoder device, method of manufacturing encoder device, drive device, table device, and robot device

文档序号：991330 发布日期：2020-10-20 浏览：2次中文

阅读说明：本技术 编码器装置及其制造方法、驱动装置、工作台装置及机械手装置 (Encoder device, method of manufacturing encoder device, drive device, table device, and robot device ) 是由三桥雄一于 2019-03-22 设计创作，主要内容包括：编码器装置具备：位置检测部,其检测移动部的位置信息；磁铁,其沿所述移动部的移动方向具有多个极性；电信号产生部,其具有根据伴随所述移动部的移动所产生的磁场变化而磁特性发生变化的磁性感应部、和用于将所述磁铁的磁感线向所述磁性感应部引导的第1磁性体,所述电信号产生部基于所述磁性感应部的磁特性而产生电信号；和第2磁性体,其配置于所述磁铁与所述磁性感应部之间,用于将所述磁铁的一个极性部分的磁感线向所述磁铁的其他极性部分引导。能够减少磁铁因不必要的磁场而产生的噪音,从而产生稳定的电信号,能够实现检测结果的可靠性的提高。(The encoder device includes: a position detection unit that detects position information of the moving unit; a magnet having a plurality of polarities along a moving direction of the moving portion; an electric signal generating unit having a magnetic induction unit whose magnetic characteristics change in accordance with a change in a magnetic field generated by movement of the moving unit, and a 1 st magnetic body for guiding the magnetic induction of the magnet to the magnetic induction unit, the electric signal generating unit generating an electric signal based on the magnetic characteristics of the magnetic induction unit; and a 2 nd magnetic body disposed between the magnet and the magnetic induction portion, for guiding a magnetic induction line of one polar portion of the magnet to the other polar portion of the magnet. Noise generated by the magnet due to an unnecessary magnetic field can be reduced, so that a stable electric signal is generated, and the reliability of a detection result can be improved.)

1. An encoder device is provided with:

a position detection unit that detects position information of the moving unit;

a magnet having a plurality of polarities along a moving direction of the moving portion;

an electric signal generating unit having a magnetic induction unit whose magnetic characteristics change in accordance with a change in a magnetic field generated by movement of the moving unit, and a 1 st magnetic body for guiding the magnetic induction of the magnet to the magnetic induction unit, the electric signal generating unit generating an electric signal based on the magnetic characteristics of the magnetic induction unit; and

and a 2 nd magnetic body disposed between the magnet and the magnetic induction unit, for guiding a magnetic induction line of one polar portion of the magnet to the other polar portion of the magnet.

2. The encoder device of claim 1,

the magnets are flat along the moving direction and have different polarities in a thickness direction orthogonal to the moving direction,

the 2 nd magnetic body is continuously disposed along the moving direction,

the 1 st magnetic body is provided so as to be capable of facing the magnet from the magnetic induction unit to the 2 nd magnetic body.

3. The encoder device of claim 1 or 2,

the magnets are flat along the moving direction and have different polarities in a width direction orthogonal to the moving direction,

a plurality of openings are provided in the 2 nd magnetic body at intervals equal to intervals between polarities different from each other in the moving direction of the magnet,

the 1 st magnetic body is provided between the 2 nd magnetic body and the magnetic induction portion, and the 1 st magnetic body guides the magnetic induction of the magnet to the magnetic induction portion through the opening of the 2 nd magnetic body.

4. The encoder device of any of claims 1 to 3,

the electric signal generating unit includes a 3 rd magnetic body for guiding the magnetic induction line passing through the magnetic induction unit to the magnet.

5. The encoder device of claim 4,

the 1 st and 3 rd magnetic bodies guide magnetic induction lines from 2 portions of the magnets located at different positions in the moving direction, the portions having different polarities from each other, to the longitudinal direction of the magnetic induction portion.

6. The encoder device of claim 4 or 5,

the moving part comprises a rotating shaft, and the rotating shaft,

in the electric signal generating part, there are 1 st time and 2 nd time between 1 cycle of the rotation of the rotating shaft, in the 1 st time, the magnetic induction line from the magnet passes through the magnetic induction part via the 1 st magnetic body and the 3 rd magnetic body, in the 2 nd time, the magnetic induction line from the magnet passes through the 2 nd magnetic body without passing through the magnetic induction part,

and when the work bench is in the 1 st time, the electric signal generating part generates an electric signal.

7. The encoder device of any of claims 4 to 6,

widths in the moving direction of the plurality of polar portions of the magnet in the moving direction are set to be narrower than an interval between a front end portion of the 1 st magnetic body and a front end portion of the 3 rd magnetic body, respectively,

and a section in which the magnetic induction line from the magnet does not pass through the magnetic induction part is provided in the moving direction.

8. The encoder device of any of claims 1 to 7,

a neutral zone is provided along the moving direction of the moving part, in which the magnetic induction line from the magnet is not guided to the magnetic induction part.

9. The encoder device of any of claims 1 to 8,

the magnets each have a plurality of magnet elements magnetized to 2 magnetic poles,

the magnet elements are respectively in a shape of a flat plate along the moving direction and a polygon having at least 3 sides.

10. The encoder device of any of claims 1 to 9,

the magnetic induction part generates a large barkhausen jump according to a magnetic field change generated along with the movement of the magnet.

11. The encoder device of any of claims 1 to 10,

the electric signal generating unit generates pulse-like electric power by the movement of the moving unit.

12. The encoder device of any of claims 1 to 11,

the position detecting device includes a battery that supplies at least a part of the electric power consumed by the position detecting unit based on the electric signal generated by the electric signal generating unit.

13. The encoder device of claim 12,

the battery is provided with a switching unit that switches the presence or absence of power supply from the battery to the position detection unit based on the electric signal generated by the electric signal generation unit.

14. The encoder device of claim 12 or 13,

the battery includes a primary battery or a secondary battery.

15. The encoder device of any of claims 12 to 14,

the position detecting unit includes a position detecting magnet and a magnetic force detecting unit, the position detecting unit being configured to detect the position information based on a magnetic field formed by the position detecting magnet, the position detecting magnet and the magnetic force detecting unit being arranged such that relative positions of the position detecting magnet and the magnetic force detecting unit change with movement of the moving unit,

the magnetic force detection unit detects a magnetic field formed by the position detection magnet using power supplied from the battery.

16. The encoder device of any of claims 1 to 15,

the position detection unit includes:

a scale that moves in conjunction with the moving portion;

an irradiation unit that irradiates the scale with light; and

and a light detection unit that detects light from the scale.

17. The encoder device of any of claims 1 to 16,

the moving part includes a rotating shaft,

the magnet and the 2 nd magnetic body are respectively in a ring belt shape,

the magnetic induction part is arranged outside the outer side surface of the 2 nd magnetic body.

18. The encoder device of claim 17,

the position detection unit includes:

an angle detection unit that detects angular position information within 1 rotation of the rotating shaft; and

and a multi-rotation information detecting unit that detects multi-rotation information of the rotating shaft as the position information.

19. A drive device is characterized by comprising:

the encoder device of any one of claims 1 to 18; and

and a power supply unit that supplies power to the moving unit.

20. A table device is characterized by comprising:

moving the object; and

the driving device of claim 19 that moves the moving object.

21. A robot device is characterized by comprising:

the drive device of claim 19; and

and the arms move relatively under the driving of the driving device.

22. A method of manufacturing an encoder device, the encoder device comprising:

a position detection unit that detects position information of the moving unit;

a magnet having a plurality of polarities along a moving direction of the moving portion;

an electric signal generating unit having a magnetic induction unit in which magnetic characteristics change according to a change in a magnetic field generated by movement of the moving unit, a power generating unit for generating an electric signal based on the magnetic characteristics of the magnetic induction unit, and a 1 st magnetic body for guiding the magnetic induction of the magnet to the magnetic induction unit; and

a 2 nd magnetic body disposed between the magnet and the magnetic induction portion, for guiding a magnetic induction line of one polar portion of the magnet to the other polar portion of the magnet,

the method of manufacturing the encoder device includes:

preparing the magnetic induction part, the power generation part, and the 1 st magnetic body;

inserting the power generating part into a 1 st hole of an assembly jig, and inserting the magnetic induction part into a 2 nd hole provided in the 1 st hole through the power generating part;

fixing the power generating part and the magnetic induction part; and

the power generating unit taken out of the assembly jig is fixed to a housing disposed on a side surface of the 2 nd magnetic body.

23. The method of manufacturing an encoder device of claim 22, comprising:

before the power generating section and the magnetic induction section are mounted on the assembly jig, at least one of the magnetic induction section and the power generating section is inspected.

24. The method of manufacturing an encoder device of claim 22, comprising:

the magnetic induction portion and the power generation portion are inspected in a state where the power generation portion and the magnetic induction portion are mounted on the assembly jig.

25. A method of manufacturing an encoder device, the encoder device comprising:

a position detection unit that detects position information of the moving unit;

a magnet having a plurality of polarities along a moving direction of the moving portion;

a 2 nd magnetic body disposed between the magnet and the magnetic induction portion, for guiding a magnetic induction line of one polar portion of the magnet to the other polar portion of the magnet,

the method of manufacturing the encoder device includes:

preparing the magnetic induction part, the power generation part, and the 1 st magnetic body;

fixing the power generating portion to a case, wherein the case is disposed on a side surface of the 2 nd magnetic body;

inserting the magnetic induction part into the power generation part through an opening provided in the housing; and

and fixing the magnetic induction part to the shell.

26. The method of manufacturing an encoder device of claim 25, comprising:

the magnetic induction portion and the power generation portion are inspected in a state where the power generation portion and the magnetic induction portion are mounted on the housing.

Technical Field

The invention relates to an encoder device, a method of manufacturing the encoder device, a driving device, a table device, and a robot device.

Background

An encoder device that detects positional information such as a rotation angle or a rotation speed of a detection target is mounted on various devices such as a robot device. As a conventional encoder device, the following devices are known: a magnetic wire such as a wiegand wire is used to convert a change in the magnetic field of a rotating magnet into an electric signal and determine the rotation speed using the electric signal (see, for example, patent document 1).

In the encoder device using the magnetic wire as described above, it is desired to reduce noise generated by an unnecessary magnetic field of the magnet, generate a stable electric signal, and improve reliability of a detection result.

Disclosure of Invention

According to the 1 st aspect, there is provided an encoder device including: a position detection unit that detects position information of the moving unit; a magnet having a plurality of polarities along a moving direction of the moving portion; an electric signal generating unit having a magnetic induction unit whose magnetic characteristics change in accordance with a change in a magnetic field generated by movement of the moving unit, and a 1 st magnetic body for guiding the magnetic induction of the magnet to the magnetic induction unit, the electric signal generating unit generating an electric signal based on the magnetic characteristics of the magnetic induction unit; and a 2 nd magnetic body disposed between the magnet and the magnetic induction portion, for guiding a magnetic induction line of one polar portion of the magnet to the other polar portion of the magnet.

According to the 2 nd aspect, there is provided a driving device including the encoder device according to the 1 st aspect and a power supply unit that supplies power to the moving unit.

According to the 3 rd aspect, there is provided a table device including a moving object and the driving device of the 2 nd aspect for moving the moving object.

According to the 4 th aspect, there is provided a robot device including the drive device according to the 2 nd aspect and an arm that is relatively moved by the drive device.

According to the 5 th aspect, there is provided a method of manufacturing an encoder device, the encoder device including: a position detection unit that detects position information of the moving unit; a magnet having a plurality of polarities along a moving direction of the moving portion; an electric signal generating unit having a magnetic induction unit in which magnetic characteristics change according to a change in a magnetic field generated by movement of the moving unit, a power generating unit for generating an electric signal based on the magnetic characteristics of the magnetic induction unit, and a 1 st magnetic body for guiding the magnetic induction of the magnet to the magnetic induction unit; and a 2 nd magnetic body disposed between the magnet and the magnetic induction portion, for guiding a magnetic induction line of one polar portion of the magnet to the other polar portion of the magnet, the method of manufacturing the encoder device including: preparing the magnetic induction part, the power generation part and the 1 st magnetic body; inserting the power generation part into a 1 st hole part of an assembly fixture, and inserting the magnetic induction part into a 2 nd hole part arranged in the 1 st hole part through the power generation part; fixing the power generation part and the magnetic induction part; and fixing the power generating part taken out of the assembly jig to a case disposed on a side surface of the 2 nd magnetic body.

According to the 6 th aspect, there is provided a method of manufacturing an encoder device, the encoder device including: a position detection unit that detects position information of the moving unit; a magnet having a plurality of polarities along a moving direction of the moving portion; an electric signal generating unit having a magnetic induction unit in which magnetic characteristics change according to a change in a magnetic field generated by movement of the moving unit, a power generating unit for generating an electric signal based on the magnetic characteristics of the magnetic induction unit, and a 1 st magnetic body for guiding the magnetic induction of the magnet to the magnetic induction unit; and a 2 nd magnetic body disposed between the magnet and the magnetic induction portion, for guiding a magnetic induction line of one polar portion of the magnet to the other polar portion of the magnet, the method of manufacturing the encoder device including: preparing the magnetic induction part, the power generation part and the 1 st magnetic body; fixing the power generating section to a case disposed on a side surface of the 2 nd magnetic body; inserting the magnetic induction part into the power generation part through an opening arranged in the shell; and fixing the magnetic induction part to the housing.

Drawings

Fig. 1 is a diagram showing an encoder device according to embodiment 1.

Fig. 2 (a) is a perspective view showing the magnet and the electric signal generating unit in fig. 1, fig. 2 (B) is a plan view showing the magnet, the electric signal generating unit, and the magnetic sensor in fig. 1, fig. 2 (C) is a side view showing the magnet and the like in fig. 2 (a) in cross section, and fig. 2 (D) is a circuit diagram showing the magnetic sensor in fig. 2 (B).

Fig. 3(a) is a perspective view showing the magnet and the electric signal generating unit of fig. 2 (a), and fig. 3 (B) is a plan view of fig. 3 (a).

Fig. 4 is a diagram showing the configuration of a power supply system and a multi-rotation information detection unit of the encoder device of fig. 1.

Fig. 5 is a diagram showing an operation in the normal rotation of the encoder device of fig. 1.

Fig. 6 (a) is a flowchart showing an example of a manufacturing method of an encoder device, and fig. 6 (B) is a flowchart showing a part of a modification of the manufacturing method.

Fig. 7 (a) is a perspective view showing the power generating unit, the magnetic induction unit, the magnetic body, and the case, and fig. 7 (B) is a perspective view showing a state in which the magnetic body is assembled to the case.

Fig. 8 (a) is a perspective view showing an assembly jig, fig. 8 (B) is a cross-sectional view showing the assembly jig, fig. 8 (C) is a perspective view showing a state where the magnetic induction portion is inserted into the power generation portion, and fig. 8 (D) is a perspective view showing a state where the electric signal generation unit is assembled to the housing.

Fig. 9 (a) is a perspective view showing the substrate, the shield plate, and the housing, and fig. 9 (B) is a cross-sectional view showing the assembled encoder device.

Fig. 10 is a flowchart showing a part of a modification of the method of manufacturing the encoder device.

Fig. 11 (a) is a perspective view showing the magnet and the electric signal generating unit according to embodiment 2, fig. 11 (B) is a plan view of fig. 11 (a), and fig. 11 (C) is a side view of fig. 11 (B).

Fig. 12 (a) is a perspective view showing a state in which the magnet is rotated by 45 ° from the state of fig. 11 (a), fig. 12 (B) is a plan view of fig. 12 (a), and fig. 12 (C) is a side view of fig. 12 (B).

Fig. 13(a) is a plan view showing the magnet and the electric signal generating unit according to embodiment 3, and fig. 13 (B) is a plan view showing a state in which the magnet is rotated by 45 ° from the state in fig. 13 (a).

Fig. 14 is a flowchart showing a method of manufacturing the encoder device according to embodiment 4.

Fig. 15 (a) is a perspective view showing the case of embodiment 4, and fig. 15 (B) is a perspective view showing the substrate, the shield plate, and the case.

Fig. 16 is a diagram showing an example of the driving device.

Fig. 17 is a diagram showing an example of the table device.

Fig. 18 is a diagram showing an example of the robot device.

Detailed Description

[ embodiment 1 ]

Embodiment 1 will be described with reference to fig. 1 to 9. Fig. 1 shows an encoder apparatus EC according to the present embodiment. In fig. 1, an encoder device EC detects rotational position information of a rotating shaft SF (moving portion) of a motor M (power supply portion). The rotating shaft SF is, for example, a rotating shaft (rotor) of the motor M, but may be a working shaft (output shaft) connected to the rotating shaft of the motor M via a power transmission unit such as a transmission and connected to a load. The rotational position information detected by the encoder device EC is supplied to the motor control unit MC. The motor control unit MC controls the rotation of the motor M using the rotational position information supplied from the encoder device EC. The motor control unit MC controls the rotation of the rotary shaft SF.

The encoder device EC includes a position detection system (position detection means) 1 and a power supply system (power supply means) 2. The position detection system 1 detects rotational position information of the rotation shaft SF. The encoder device EC is a so-called multi-rotation absolute encoder that detects rotation position information including multi-rotation information indicating the number of rotations of the rotation shaft SF and angular position information indicating an angular position (rotation angle) of less than one rotation. The encoder device EC includes a multiple rotation information detection unit 3 that detects multiple rotation information of the rotation shaft SF, and an angle detection unit 4 that detects an angular position of the rotation shaft SF.

For example, in a state (for example, a normal state) in which a power supply of a device (for example, a driving device, a table device, or a robot device) on which the encoder device EC is mounted is turned on, at least a part of the position detection system 1 (for example, the angle detection unit 4) receives supply of electric power from the device and operates. In a state (for example, an abnormal state or a standby state) in which, for example, the power supply of the apparatus on which the encoder apparatus EC is mounted is not turned on, at least a part of the position detection system 1 (for example, the multi-rotation information detection unit 3) receives the supply of electric power from the power supply system 2 and operates. For example, in a state where the supply of power from the device on which the encoder device EC is mounted is interrupted, the power supply system 2 intermittently (intermittently) supplies power to at least a part of the position detection system 1 (for example, the multi-rotation information detection unit 3), and the position detection system 1 detects at least a part of the rotational position information of the rotating shaft SF (for example, the multi-rotation information) when power is supplied from the power supply system 2.

The multi-rotation information detecting unit 3 detects multi-rotation information by, for example, magnetism. The multi-rotation information detection unit 3 includes, for example, a magnet 11, a magnetism detection unit 12, a detection unit 13, and a storage unit 14. The magnet 11 is a block-shaped divided magnet or a ring-shaped magnet, and is provided on the bottom surface (inside the side surface) of a yoke member 18 (described later in detail) having a short cylindrical side surface and a ring-shaped bottom surface. For example, the yoke member 18 is fixed to the rotation shaft SF via a disc-shaped support member 15. A flat plate-like disk 5 of an annular band is provided on the upper surface of the yoke member 18 so as to cover the magnet 11. Since the disk 5 and the yoke member 18 rotate together with the rotation shaft SF, the magnet 11 rotates in conjunction with the rotation shaft SF. The relative positions of the magnet 11 and the magnetic force detector 12 change with the rotation of the rotating shaft SF. The strength and direction of the magnetic field in the magnetic force detection unit 12 formed by the magnet 11 change with the rotation of the rotation shaft SF. The magnetic force detector 12 detects the magnetic field formed by the magnet 11, and the detector 13 detects the positional information of the rotating shaft SF based on the result of the magnetic field formed by the magnet detected by the magnetic force detector 12. The storage unit 14 stores the position information detected by the detection unit 13. The magnet 11 may be configured to rotate relative to the rotation axis SF.

The angle detection unit 4 is an optical or magnetic encoder and detects position information (angular position information) within one rotation of the disk 5. When the angle detection unit 4 is, for example, an optical encoder, the angular position within one rotation of the rotation shaft SF is detected by, for example, reading pattern information of the disk 5 by a light receiving element. The pattern information of the disc 5 is, for example, a light and dark slit-like pattern on the disc 5. The angle detection unit 4 detects the angular position information of the rotation axis SF which is the same as the detection target of the multi-rotation information detection unit 3. The angle detection unit 4 includes a light emitting element 21, a disk 5, a light receiving sensor 22, and a detection unit 23.

The disk 5 rotates in conjunction with the rotation shaft SF. An incremental scale and an absolute scale S are formed on the upper surface of the disk 5 (the surface facing the light-emitting element 21 and the light-receiving sensor 22). The scale S may be provided on another disk-shaped member (not shown) fixed to the rotation shaft SF, or may be a member integrated with the member. For example, the disk 5 may be provided between the magnet 11 and the motor M. The scale S may be provided at least on the inner side and the outer side of the magnet 11.

The light emitting element 21 (irradiation unit, light emitting unit) irradiates the scale S of the disk 5 with light. The light receiving sensor 22 (light detecting unit) detects light emitted from the light emitting element 21 and passing through the scale S. In fig. 1, the angle detection unit 4 is a reflection type, and the light receiving sensor 22 detects light reflected by the scale S. The angle detection unit 4 may be of a transmissive type. The light receiving sensor 22 supplies a signal indicating the detection result to the detection unit 23. The detector 23 detects the angular position of the rotating shaft SF using the detection result of the light receiving sensor 22. For example, the detection unit 23 detects the angular position of the 1 st resolution using the result of detecting light from the absolute scale. The detector 23 detects the angular position of the 2 nd resolution higher than the 1 st resolution by performing interpolation calculation on the angular position of the 1 st resolution using the result of detecting the light from the incremental scale.

In the present embodiment, the encoder device EC includes a signal processing unit 25. The signal processing unit 25 calculates and processes a detection result obtained by the position detection system 1. The signal processing unit 25 includes a combining unit 26 and an external communication unit 27. The combining unit 26 acquires the angular position information of the 2 nd resolution detected by the detecting unit 23. The combining unit 26 also acquires multi-rotation information of the rotation axis SF from the storage unit 14 of the multi-rotation information detecting unit 3. The combining unit 26 combines the angular position information from the detecting unit 23 and the multi-rotation information from the multi-rotation information detecting unit 3 to calculate the rotation position information. For example, the detection result of the detection unit 23 is θ (rad), and when the detection result of the multiple rotation information detection unit 3 is n cycles, the synthesis unit 26 calculates (2 π × n + θ) (rad) as the rotation position information. The rotational position information may be information obtained by combining multi-rotation information and angular position information of less than one rotation.

The combining unit 26 supplies the rotational position information to the external communication unit 27. The external communication unit 27 is communicably connected to the communication unit MCC of the motor control unit MC by wire or wireless. The external communication unit 27 supplies the rotation position information in digital form to the communication unit MCC of the motor control unit MC. The motor control unit MC decodes the rotational position information from the external communication unit 27 of the angle detection unit 4 as appropriate. The motor control unit MC controls the rotation of the motor M by controlling the electric power (drive electric power) supplied to the motor M using the rotational position information.

The power supply system 2 includes a 1 st electric signal generation unit 31A and a 2 nd electric signal generation unit 31B, a battery (battery)32, and a switching unit 33. The electric signal generating units 31A, 31B generate electric signals by rotation of the rotation shaft SF, respectively. The electrical signal includes, for example, a waveform of electric power (current, voltage) changing with time. The electric signal generating units 31A, 31B generate electric power as electric signals by magnetic fields that vary based on the rotation of the rotating shaft SF, respectively, for example. For example, the electric signal generating units 31A and 31B generate electric power by the multi-rotation information detecting unit 3 detecting a change in the magnetic field formed by the magnet 11 at the multi-rotation position of the rotation shaft SF. The electrical signal generating units 31A and 31B are arranged such that the angular position of the magnet 11 changes with the rotation of the rotation shaft SF. The electric signal generating units 31A and 31B generate a positive pulse-like electric signal or a negative pulse-like electric signal when, for example, the relative positions of the electric signal generating units 31A and 31B and the magnet 11 are respectively predetermined positions. By full-wave rectifying the electric signal by a rectifier or the like, a direct-current electric signal that can be easily used in a circuit or the like can be obtained.

The battery 32 supplies at least a part of the electric power consumed by the position detection system 1 based on the electric signals generated by the electric signal generation units 31A, 31B. The battery 32 includes a primary battery 36 such as a button-type battery or a dry cell battery, and a rechargeable secondary battery 37 (see fig. 4). The secondary battery of the battery 32 can be charged with, for example, an electric signal (e.g., current) generated by the electric signal generating units 31A, 31B. The battery 32 is held by the holding portion 35. The holding portion 35 is, for example, a circuit board or the like provided with at least a part of the position detection system 1. The holding unit 35 holds, for example, the detection unit 13, the switching unit 33, and the storage unit 14. The holding portion 35 is provided with, for example, a plurality of battery cases capable of accommodating the batteries 32, and electrodes, wirings, and the like connected to the batteries 32.

The switching unit 33 switches the presence or absence of power supply from the battery 32 to the position detection system 1 based on the electric signals generated by the electric signal generation units 31A and 31B. For example, the switching unit 33 starts the supply of electric power from the battery 32 to the position detection system 1 by setting the level of the electric signal generated by the electric signal generation units 31A and 31B after full-wave rectification to be equal to or higher than a threshold value. For example, the switching unit 33 stops the supply of electric power from the battery 32 to the position detection system 1 by making the level of the electric signal generated by the electric signal generation units 31A and 31B after full-wave rectification smaller than a threshold value. For example, the switching unit 33 stops the supply of electric power from the battery 32 to the position detection system 1 by making the electric power generated by the electric signal generation units 31A and 31B smaller than a threshold value. For example, when the electric signal generating means 31A and 31B generate a pulse-like electric signal, the switching unit 33 starts the supply of electric power from the battery 32 to the position detection system 1 when the level (electric power) of the electric signal after full-wave rectification rises from a low level to a high level, and stops the supply of electric power from the battery 32 to the position detection system 1 after a predetermined time has elapsed since the level (electric power) changes to a low level.

Fig. 2 (B) is a plan view showing magnet 11, electric signal generating units 31A and 31B, and 2 magnetic sensors 51 and 52 as magnetism detecting unit 12 in fig. 1, and fig. 2 (C) is a side view showing yoke member 18 in fig. 2 (B) in cross section. Fig. 2 (a) is a perspective view showing the magnet 11 and the 1 electric-signal generating unit 31A, and fig. 2 (D) is a circuit diagram of the magnetic sensor 51. In fig. 2 (a) and the like, the rotation axis SF in fig. 1 is indicated by a straight line.

In fig. 2 (a) to (C), the magnet 11 is mounted on the yoke member 18 so that the direction and intensity of the magnetic field in the axial direction (also referred to as axial direction) AD1, which is a direction parallel to a straight line (symmetry axis) passing through the center of the rotation axis SF, change due to rotation. The magnet 11 is composed of the following magnets: magnets of N poles 16A and 16C, which are 1 pair of rectangular shapes and are arranged symmetrically with respect to rotation axis SF, magnets of S poles 16B and 16D, which are located at positions rotated by 90 ° around rotation axis SF with respect to N poles 16A and 16C, and magnets of S poles 17A, 17C and N poles 17B, 17D, which are arranged on the back surfaces (surfaces on the same side as motor M) of N poles 16A, 16C and S poles 16B, 16D, respectively, and have the same shape. The magnet 11 is a combination of a plurality of permanent magnets (4 in fig. 2 a) magnetized to have 4 pairs of polarities in the circumferential direction (or also referred to as the θ direction, the circumferential direction, and the rotational direction) around the rotation axis SF. The magnet 11 may be formed of 1 ring-shaped (ring-shaped) magnet, for example, and may be magnetized to have N-pole 16A to S-pole 16D. For example, a member including the N-pole 16A and the S-pole 17A can be regarded as one magnet element magnetized to have 2 magnetic poles (N-pole and S-pole). The member including the N-pole 16A and the S-pole 17A can be manufactured by magnetizing a single ferromagnetic body having a size in which the N-pole 16A and the S-pole 17A are combined, for example.

The main surface of the magnet 11, i.e., the front surface (the surface opposite to the motor M in fig. 1) and the rear surface, are substantially perpendicular to the rotation axis SF. In the magnet 11, the angles of the north poles 16A to 16D on the front side and the south poles 17A to 17D on the back side (e.g., the positions of the north and south poles) are shifted by 90 ° (180 ° in phase).

For convenience of description, counterclockwise rotation when viewed from the front end side of the rotation shaft SF (the side opposite to the motor M in fig. 1) is referred to as normal rotation, and clockwise rotation is referred to as reverse rotation. In addition, the angle of positive rotation is represented by a positive value, and the angle of reverse rotation is represented by a negative value. Further, counterclockwise rotation when viewed from the rear end side of the rotation shaft SF (the motor M side in fig. 1) may be defined as normal rotation, and clockwise rotation may be defined as reverse rotation.

In the coordinate system fixed to the magnet 11, the angular position between the S-pole 16D and the N-pole 16A in the circumferential direction is defined as the 1 st position 11a, and the angular positions rotated by 90 ° in order from the 1 st position 11a (the intermediate between the N-pole and the S-pole) are represented by the 2 nd position 11b, the 3 rd position 11c, and the 4 th position 11D, respectively.

In the 1 st section rotated 90 ° counterclockwise from the 1 st position 11a, the N pole 16A is disposed on the front side of the magnet 11, and the S pole 17A is disposed on the back side of the magnet 11. In the 1 st section, the direction of the magnetic field of the magnet 11 in the axial direction is substantially parallel to an axial direction AD1 (see fig. 2C) from the front surface side to the back surface side of the magnet 11. In the 1 st segment, the intensity of the magnetic field is maximum at the center position of the N-pole 16A and minimum near the 1 st position 11a and the 4 th position 11 d.

In the 2 nd section (the section in which the S-pole is arranged on the front surface side of the magnet 11 and the N-pole is arranged on the back surface side of the magnet 11) rotated counterclockwise by 90 ° from the 2 nd position 11b, the direction of the magnetic field of the magnet 11 in the axial direction is substantially the direction from the back surface side to the front surface side of the magnet 11 (the direction opposite to the direction of the axial direction AD1 in fig. 2C). In the 2 nd section, the intensity of the magnetic field is maximum at the center of the S-pole 16D and minimum near the 1 st position 11a and the 2 nd position 11 b. Similarly, in the 3 rd zone rotated 90 ° counterclockwise from the 3 rd position 11c and the 4 th zone rotated 90 ° counterclockwise from the 4 th position 11d, the axial direction of the magnetic field of the magnet 11 is approximately the direction from the front surface side to the back surface side of the magnet 11 and the direction from the back surface side to the front surface side, respectively.

In this manner, the direction of the magnetic field formed by the magnet 11 in the axial direction is reversed in order from the 1 st position 11a to the 4 th position 11 d. However, in the present embodiment, the magnets of the N-pole 16A to S-pole 16D (S-pole 17A to N-pole 17D) are circumferentially spaced from each other, and therefore the magnetic field becomes small in the region from the 1 st position to the 4 th position and the vicinity thereof. The magnet 11 forms an alternating magnetic field in which the direction of the magnetic field in the axial direction is reversed with respect to a coordinate system fixed to the outside of the magnet 11 as the magnet 11 rotates. The electric signal generating units 31A and 31B are disposed on the upper surface and the outer surface of the magnet 11 (for example, in the vicinity of the side surface of the rotation shaft SF and in the vicinity of the side surface of the yoke member 18 (side yoke 18S)) when viewed from the normal direction of the main surface of the magnet 11.

In the present embodiment, the main bodies of the electric signal generating units 31A and 31B (including the magnetic induction portions 41A and 41B and the power generating portions 42A and 42B described later) are provided at intervals from the magnet 11 in a radial direction (for example, a radial direction or a radial direction) perpendicular to the rotation axis SF or in a direction parallel to the radial direction, and are not in contact with the magnet 11. The 1 st electric signal generating unit 31A includes a magnetic induction portion 41A, a power generating portion 42A, a 1 st magnetic body 45A, and a 3 rd magnetic body 46A. The 1 st magnetic element 45A and the 3 rd magnetic element 46A are substantially axisymmetrical in shape. In addition, one of the 1 st magnetic body 45A and the 3 rd magnetic body 46A can be omitted.

In the present embodiment, the yoke member 18 (e.g., a guide member for a magnetic induction wire or a magnetic field) is formed of a ferromagnetic material such as iron, and a bottom surface on which the magnet 11 is placed and which has the opening 18a is referred to as a back yoke 18B, and a short cylindrical side surface portion surrounding the back yoke 18B is referred to as a side yoke 18S. The back yoke 18B functions to guide the magnetic induction lines (or magnetic lines) of the portion of a predetermined polarity (for example, the S-pole 17A) of the magnet 11 placed on the upper surface thereof to the portions of the other polarities (for example, the N- poles 17B, 17D). The side yoke 18S functions to guide the magnetic induction of a portion of a predetermined polarity (for example, the N-pole 16A) close to the side yoke 18S to a portion of another polarity (for example, the S-pole 17A) on the back surface of the portion and to portions of other polarities (for example, the S- poles 16B and 16D) adjacent to the portion in the circumferential direction. The yoke member 18 (side yoke 18S) is a member other than the 1 st magnetic body 45A and the 3 rd magnetic body 46A (a member different from the 1 st magnetic body 45A and the 3 rd magnetic body 46A). In the present embodiment, the side yoke 18S can also be referred to as a 2 nd magnetic body, and therefore, the magnetic body 46A of the electric signal generating unit 31A is referred to as a 3 rd magnetic body. As described above, in the electric signal generating unit 31A according to the present embodiment, the yoke member 18 prevents the magnetic flux lines of the magnet 11 from being directly affected by the magnet 11, and thus a stable and efficient signal can be generated.

The magnetic induction portion 41A and the power generation portion 42A of the electric signal generation unit 31A are fixed to the vicinity of the outer surface (or the outer diameter side) of the side yoke 18S of the magnet 11 or above the vicinity of the side surface thereof continuously surrounding the moving portion in the moving direction (for example, the rotation direction of the rotation shaft SF), and the relative positions with respect to the respective positions on the magnet 11 change with the rotation of the magnet 11. For example, in fig. 2B, the 1 st position 11A of the magnet 11 is arranged at the center of the 1 st electric signal generating means 31A, and when the magnet 11 rotates 1 rotation in the forward direction (counterclockwise) from this state, the 1 st position 11A to the 4 th position 11d pass through the vicinity of the electric signal generating means 31A in order. The magnetic induction portion 41A and the power generation portion 42A of the electric signal generation unit 31A may be fixed near the inner surface (or the inner diameter side) of the side yoke 18S or above the vicinity of the side surface thereof.

The magnetic induction portion 41A is a magnetic induction wire such as a wiegand wire. In the magnetic induction portion 41A, a large barkhausen jump (wiegand effect) is generated by a change in magnetic field accompanying rotation of the magnet 11. The magnetic induction portion 41A is an elongated cylindrical member, and its axial direction is set to the circumferential direction of the rotation shaft SF, for example. Hereinafter, the axial direction of the magnetic induction portion 41A, i.e., the direction perpendicular to the cross section of the circular shape (or may be a polygonal shape or the like) of the magnetic induction portion 41A, is also referred to as the longitudinal direction LD1 of the magnetic induction portion 41A. An alternating magnetic field is applied to the magnetic induction portion 41A in the axial direction (longitudinal direction), and when the alternating magnetic field is inverted, a magnetic domain wall is generated from one end in the axial direction to the other end. As shown in fig. 2 (B), the electrical signal generating unit 31A can be downsized by setting the longitudinal direction LD1 of the magnetic induction portion 41A to the circumferential direction of the rotation axis SF. In the present embodiment, the side yoke 18S prevents the magnetic flux lines on the side surface of the magnet 11 from leaking to the magnetic induction portion 41A (described in detail later), and therefore the longitudinal direction LD1 of the magnetic induction portion 41A may be any direction. For example, the longitudinal direction LD1 may be parallel to the axial direction AD1, parallel to a radial direction with respect to the rotation axis SF, or may be a direction obliquely crossing the axial direction AD1, the radial direction, or the like.

The 1 st magnetic element 45A and the 3 rd magnetic element 46A are formed of a ferromagnetic material such as iron, cobalt, or nickel, for example. The 1 st magnetic body 45A is provided so as to straddle the side yoke 18S between the surface of the magnet 11 and one end of the magnetic induction portion 41A, and the 3 rd magnetic body 46A is provided so as to straddle the side yoke 18S between the surface of the magnet 11 and the other end of the magnetic induction portion 41A. In the substantially rectangular flat plate-like portions adjacent to the magnetic induction portions 41A of the 1 st and 3 rd magnetic bodies 45A, 46A, elongated notch portions 45Aa, 46Aa for housing the magnetic induction portions 41A when the adjustment electric signal generating unit 31A is assembled are formed in a range from the upper surface to the central portion. The magnet 11-side end portions 45Ab and 46Ab of the 1 st and 3 rd magnetic bodies 45A and 46A are substantially at the same position as 1 side of the portions of 2 polarities (the N-pole 16A and the S-pole 17A) different from each other in the circumferential direction at the 1 st position 11a, and are inclined inward (in an inverted "chevron" shape) symmetrically in a substantially parallel manner. In other words, the front end portion 45Ab of the 1 st magnetic body 45A and the front end portion 46Ab of the 3 rd magnetic body 46A are paired (axisymmetric), and the front end portions 45Ab, 46Ab are formed along a direction (inward direction) in which the reference lines of the axisymmetric directions approach each other.

As shown in fig. 2a, when the electric signal generating unit 31A is located at least one angular position within 1 rotation of the magnet 11 (for example, an angular position at which the electric signal is generated from the electric signal generating units 31A and 31B), the tip end portions 45Ab and 46Ab are arranged such that the center line CL1A of the tip end portion 45Ab of the 1 st magnetic body 45A and the center line CL1B of the tip end portion 46Ab of the 3 rd magnetic body 46A are parallel to two sides (both side surfaces) of the adjacent 2-polarity portions of the magnet 11 (the N-pole 16A and the S-pole 16D in fig. 2 a) on the side of the electric signal generating unit 31A (the tilt angle of the tip end portions 45Ab and 46Ab is determined), when viewed in the axial direction of the rotation shaft SF. In addition, at least one angular position within 1 rotation of the magnet 11, the 1 st magnetic body 45A is disposed at a position facing a portion of the magnet 11 of a predetermined polarity (N pole 16A to S pole 16D) in the axial direction of the rotation shaft SF or in a direction parallel thereto. Further, at least a part of the 1 st magnetic body 45A and the 3 rd magnetic body 46A is disposed at a position where a part of the magnet 11 having a predetermined polarity (the N pole 16A to the S pole 16D) overlaps the side yoke 18S, respectively, when viewed in the axial direction of the rotating shaft SF.

The polarities of the magnets 11 at the tip portions 45Ab, 46Ab of the 1 st magnetic body 45A and the 3 rd magnetic body 46A are always opposite to each other at the 1 st position 11a to the 4 th position 11D and the vicinity thereof, and when the tip portion 45Ab of the 1 st magnetic body 45A is positioned in the vicinity of the N pole 16A (or the S pole 16B), the tip portion 46Ab of the 3 rd magnetic body 46A is positioned in the vicinity of the S pole 16D (or the N pole 16A). Therefore, at the positions 11A to 11D and the positions in the vicinity thereof, the 1 st magnetic body 45A and the 3 rd magnetic body 46A guide the magnetic induction from 2 portions (for example, the N pole 16A and the S pole 16D) of the magnets 11 having different polarities from each other in the circumferential direction of the magnets 11 to the longitudinal direction of the magnetic induction portion 41A.

The power generation unit 42A is a high-density coil or the like disposed so as to be wound around the magnetic induction unit 41A. In the present embodiment, the power generation unit 42A and the magnetic induction unit 41A are manufactured or prepared separately from each other, and the magnetic induction unit 41A is inserted into the through hole 42Ac in the center of the power generation unit 42A when the encoder device EC is assembled, as an example (see fig. 7 a). Further, 2 end portions of the magnetic induction portion 41A protruding from both ends of the power generation portion 42A are housed in the notch portions 45Aa, 46Aa of the 1 st magnetic body 45A, 3 rd magnetic body 46A. In this case, for example, 2 end portions of the magnetic induction portion 41A slightly protrude outward of the notch portions 45Aa and 46 Aa. In the power generation portion 42A, electromagnetic induction is generated with generation of a magnetic domain wall in the magnetic induction portion 41A, and an induced current flows. When the 1 st to 4 th positions of the magnet 11 pass near the center of the electric signal generating unit 31A (the center of the distal end portions of the magnetic bodies 45A and 46A), a pulse-like current (electric signal or power) is generated in the power generating unit 42A.

The direction of the current generated in the power generation section 42A changes depending on the direction before and after the magnetic field reversal. For example, when the magnetic field is reversed from the front side toward the back side of the magnet 11, the direction of the generated current is opposite to the direction of the generated current when the magnetic field is reversed from the back side toward the front side of the magnet 11. The electric power (induced current) generated at the power generation section 42A can be set according to, for example, the number of turns of the high-density coil.

The magnetic induction portion 41A, the power generation portion 42A, and the 1 st magnetic body 45A and the 3 rd magnetic body 46A are housed in the case 6 (see fig. 8D). The housing 6 can also be referred to as a casing. The housing 6 is provided with terminals 42Aa and 42 Ab. One end and the other end of the high-density coil of the power generation unit 42A are electrically connected to the terminals 42Aa and 42Ab, respectively. The electric power generated by the power generation unit 42A can be taken out to the outside of the 1 st electric signal generation unit 31A via the terminals 42Aa and 42 Ab. Further, the housing 6 is disposed so as not to contact the rotation shaft SF to which the yoke member 18 (e.g., the side yoke 18S) is fixed.

The 2 nd electric signal generating unit 31B is disposed at an angular position forming an angle larger than 0 ° and smaller than 180 ° from the angular position at which the 1 st electric signal generating unit 31A is disposed. The angle between the electric signal generating units 31A, 31B is selected from a range of, for example, 112.5 ° to 157.5 °, and is about 135 ° in fig. 2 (B). The 2 nd electric signal generating unit 31B has the same configuration as the 1 st electric signal generating unit 31A. The 2 nd electric signal generating unit 31B includes a magnetic induction portion 41B, a power generating portion 42B, a 1 st magnetic body 45B, and a 3 rd magnetic body 46B. The magnetic induction portion 41B, the power generation portion 42B, and the 1 st magnetic body 45B and the 3 rd magnetic body 46B are the same as the magnetic induction portion 41A and the power generation portion 42A of the electric signal generation unit 31A, and the 1 st magnetic body 45A and the 3 rd magnetic body 46A, respectively, and the description thereof will be omitted. The 2 nd magnetic induction portion 41B, the 2 nd power generation portion 42B, and the 1 st magnetic body 45B, the 3 rd magnetic body 46B are accommodated in the case 6 at portions on the 2 nd magnetic induction portion 41B side. The case 6 is provided with terminals 42Ba and 42 Bb. The power generated by the 2 nd power generation unit 42B can be taken out to the outside of the 2 nd electric signal generation unit 31B via the terminals 42Ba, 42 Bb.

The magnetic force detector 12 includes magnetic sensors 51 and 52. The magnetic sensor 51 is disposed at an angular position greater than 0 ° and less than 180 ° with respect to the 2 nd magnetic sensing portion 41B (the 2 nd electric signal generation unit 31B) in the rotation direction of the rotation shaft SF. The magnetic sensor 52 is disposed at an angular position (about 45 ° in fig. 2 (B)) greater than 22.5 ° and less than 67.5 ° with respect to the magnetic sensor 51 in the rotation direction of the rotation shaft SF.

As shown in fig. 2D, the magnetic sensor 51 includes a magnetoresistive element 56, a bias magnet (not shown) for applying a magnetic field of a predetermined intensity to the magnetoresistive element 56, and a waveform shaping circuit (not shown) for shaping a waveform from the magnetoresistive element 56. The magnetoresistive element 56 has a full bridge configuration in which elements 56a, 56b, 56c, and 56d are connected in series. The power supply terminal 51p is connected to a signal line between the elements 56a and 56c, and the ground terminal 51g is connected to a signal line between the elements 56b and 56 d. The 1 st output terminal 51a is connected to a signal line between the elements 56a and 56b, and the 2 nd output terminal 51b is connected to a signal line between the elements 56c and 56 d. The magnetic sensor 52 has the same configuration as the magnetic sensor 51, and the description thereof is omitted.

Next, the operation of the 1 st electric signal generating unit 31A of the present embodiment will be described. Hereinafter, the magnetic induction portion 41A and the power generation portion 42A of the 1 st electric signal generation unit 31A in fig. 2 (B) will be described as the magnetic induction member 47 in an integrated manner. The longitudinal direction of the magnetic induction member 47 is the same as the longitudinal direction of the magnetic induction portion 41A, and the center of the magnetic induction member 47 in the longitudinal direction is the same as the center of the magnetic induction portion 41A in the longitudinal direction. The operation of the 2 nd electric signal generating unit 31B is the same as that of the 1 st electric signal generating unit 31A, and therefore, the description thereof is omitted.

When the center of the electric signal generating unit 31A is located at or near the 1 st to 4 th positions 11A to 11D in fig. 2 (B), the polarities of the magnets 11 of the tip portions 45Ab, 46Ab of the 1 st and 3 rd magnetic bodies 45A, 46A are always opposite to each other, and when the tip portion 45Ab of the 1 st magnetic body 45A is located near the N-pole 16A (or the S-pole 16B), the tip portion 46Ab of the 3 rd magnetic body 46A is located near the S-pole 16D (or the N-pole 16A). A magnetic circuit MC1 including magnetic induction lines oriented in the longitudinal direction of the magnetic induction portion 41A is formed by the magnet 11, the 1 st magnetic body 45A, the magnetic induction portion 41A, and the 3 rd magnetic body 46A. Further, for example, at or near the 1 st position 11a, the magnetic induction line from the N pole 16A facing the magnetic induction member 47 in the radial direction of the rotation axis SF is directed to the S pole 17A on the back surface of the adjacent S pole 16D and N pole 16A along the magnetic path MC2 formed in the side yoke 18S of the yoke member 18 (see fig. 2C). Therefore, the magnetic induction lines in the radial direction from the N-pole 16A toward the rotation axis SF do not extend in the longitudinal direction of the magnetic induction portion 41A, and the magnetic induction lines in the opposite direction that cancel the original magnetic induction lines in the longitudinal direction of the magnetic induction portion 41A do not work. Similarly, when the position of the magnet 11 in the rotational direction is at an arbitrary position, the magnetic induction lines directed from the portion of the magnet 11 of the predetermined polarity toward the radial direction of the rotation shaft SF are guided to the portion of the other polarity via the side yoke 18S, and therefore unnecessary magnetic induction lines other than the magnetic induction lines guided via the magnetic bodies 45A and 46A are not guided in the longitudinal direction of the magnetic induction portion 41A. As a result, the encoder device EC can always obtain a high-output pulse from the magnetic induction member 47.

Fig. 3 (B) shows a state in which the magnet 11 and the yoke member 18 are rotated by 45 ° clockwise from the state of fig. 2 (B), and fig. 3(a) shows a perspective view of the state. In fig. 3B, the center (the middle between the 1 st position 11A and the 4 th position 11 d) or the vicinity of the N-pole 16A is located at the center of the electric signal generating unit 31A, and the tip portions of the 1 st magnetic body 45A and the 3 rd magnetic body 46A of the electric signal generating unit 31A are located above the same N-pole 16A. That is, when viewed in the axial direction of rotation shaft SF, center line CL1a at the tip end of 1 st magnetic element 45A and center line CL1b at the tip end of 3 rd magnetic element 46A are inclined so as to gradually approach each other toward the center of rotation shaft SF above the portion of magnet 11 having the same polarity (N pole 16A in fig. 3 a). Therefore, the magnetic flux from the N-pole 16A toward the 1 st magnetic body 45A (in the radial direction of the rotation shaft SF) is guided to the adjacent S-pole 16B via the magnetic path MC3 at the tip end of the 1 st magnetic body 45A and the magnetic path MC4 of the side yoke 18S, without going toward the magnetic induction member 47. Similarly, the magnetic flux from the N-pole 16A toward the 3 rd magnetic body 46A (in the radial direction of the rotation shaft SF) is guided to the adjacent S-pole 16D via the magnetic path MC3 at the tip end of the 3 rd magnetic body 46A and the magnetic path MC4 of the side yoke 18S, without going toward the magnetic induction member 47. Similarly, even when the center or the vicinity of the center of the S pole 16B, N, 16C, S, 16D is located at the center of the electric signal generating unit 31A, the magnetic induction line directed radially from the S pole 16B, N, 16C, S, 16D toward the rotation axis SF is guided to the portion of the other polarity via the side yoke 18S, and therefore, the magnetic induction line is not guided in the longitudinal direction of the magnetic induction member 47. Therefore, no induced current is generated in the magnetic induction member 47.

As described above, in the electric signal generating unit 31A of the present embodiment, during 1 rotation of the rotating shaft SF, there are a 1 st time (a period centered on the time point of fig. 2 (B)) when the magnetic induction line from the magnet 11 passes through the magnetic induction portion 41A via the 1 st magnetic body 45A and the 3 rd magnetic body 46A, and a 2 nd time (a period centered on the time point of fig. 3 (B)) when the magnetic induction line from the magnet 11 passes through the side yoke 18S (the 2 nd magnetic body) and does not pass through the magnetic induction portion 41A (is difficult to pass), and at the 1 st time, the electric signal is generated in the electric signal generating unit 31A. The interval of the magnet 11 at time 2 (interval of a predetermined angle of 1 rotation) may be referred to as a neutral interval (time 2) in which the magnetic field becomes substantially 0 in the magnetic induction portion 41A.

Therefore, according to the electric signal generating unit 31A of the present embodiment, by switching the rotation of the magnet 11 and the yoke member 18 from the 2 nd time, which is a period in the longitudinal direction in which the magnetic induction line from the magnet 11 does not pass through the magnetic induction member 47 shown in fig. 3 (B), to the 1 st time, which is a period in the longitudinal direction in which the magnetic induction line from the magnet 11 passes through the magnetic bodies, that is, the 1 st magnetic body 45A and the 3 rd magnetic body 46A, as shown in fig. 2 (B), the magnetic induction line of the magnetic induction portion 41A changes drastically in the longitudinal direction, and a pulse with a higher output can be generated from the power generating portion 42A.

Further, since the side yoke 18S is disposed so as to cover the side surface of the magnet 11 and the magnetic induction lines of the magnet 11 do not leak outside the outer side surface of the side yoke 18S, the magnetic induction member 47 is disposed close to the outer side surface of the side yoke 18S, and a high-output electric signal can be obtained from the magnetic induction member 47 even if the distance between the magnetic induction member 47 and the magnet 11 is narrowed. Therefore, the encoder apparatus EC can obtain a high-output pulse and miniaturize the electric signal generating unit 31A.

Fig. 4 shows the circuit configuration of the power supply system 2 and the multi-rotation information detection unit 3 according to the present embodiment. In fig. 4, the power supply system 2 includes a 1 st electric signal generation unit 31A, a rectifier module (rectifier stack)61, a 2 nd electric signal generation unit 31B, a rectifier module 62, and a battery 32. The power supply system 2 includes a regulator (regulator)63 as the switching unit 33 shown in fig. 1.

The rectifier unit 61 is a rectifier that full-wave rectifies the current (positive pulse or negative pulse) flowing from the 1 st electric signal generating unit 31A. The 1 st input terminal 61A of the rectifying unit 61 is connected to the terminal 42Aa of the 1 st electric signal generating unit 31A. The 2 nd input terminal 61b of the rectifying module 61 is connected to the terminal 42Ab of the 1 st electric signal generating unit 31A. The ground terminal 61g of the rectifying unit 61 is connected to a ground line GL to which the same potential as that of the signal ground line SG is supplied. When the multi-rotation information detecting unit 3 operates, the potential of the ground line GL becomes a reference potential of the circuit. The output terminal 61c of the rectifying unit 61 is connected to the control terminal 63a of the regulator 63.

The rectifier 62 is a rectifier that full-wave rectifies the current (positive pulse or negative pulse) flowing from the 2 nd electric signal generating unit 31B. The 1 st input terminal 62a of the rectifying module 62 is connected to the terminal 42Ba of the 2 nd electric signal generating unit 31B. The 2 nd input terminal 62B of the rectifying module 62 is connected to the terminal 42Bb of the 2 nd electric signal generating unit 31B. The ground terminal 62g of the rectifying unit 62 is connected to the ground line GL. The output terminal 62c of the rectifying unit 62 is connected to the control terminal 63a of the regulator 63.

The regulator 63 regulates the power supplied from the battery 32 to the position detection system 1. The regulator 63 may include a switch 64 provided on a power supply path between the battery 32 and the position detection system 1. The regulator 63 controls the operation of the switch 64 based on the electric signals generated by the electric signal generating units 31A and 31B.

The input terminal 63b of the regulator 63 is connected to the battery 32. Output terminal 63c of regulator 63 is connected to power supply line PL. The ground terminal 63g of the regulator 63 is connected to the ground line GL. The control terminal 63a of the regulator 63 is an enable terminal, and the regulator 63 maintains the potential of the output terminal 63c at a predetermined voltage in a state where a voltage equal to or higher than a threshold value is applied to the control terminal 63 a. When the counter 67 is formed of a CMOS or the like, the output voltage (the predetermined voltage) of the regulator 63 is, for example, 3V. The operating voltage of the nonvolatile memory 68 of the storage unit 14 is set to, for example, the same voltage as a predetermined voltage. The predetermined voltage is a voltage necessary for supplying electric power, and may be a fixed voltage value or a voltage that changes stepwise.

The switch 64 has a 1 st terminal 64a connected to the input terminal 63b and a 2 nd terminal 64b connected to the output terminal 63 c. The regulator 63 uses the electric signal supplied from the electric signal generating units 31A and 31B to the control terminal 63a as a control signal (enable signal), and switches between a conduction state and an insulation state between the 1 st terminal 64a and the 2 nd terminal 64B of the switch 64. For example, the switch 64 includes a switching element such as a MOS or a TFT, the 1 st terminal 64a and the 2 nd terminal 64b are a source electrode and a drain electrode, and the gate electrode is connected to the control terminal 63 a. The switch 64 charges the gate electrode with an electric signal (power) generated by the electric signal generation units 31A and 31B, and when the potential of the gate electrode is equal to or higher than a threshold value, the source electrode and the drain electrode are in a conductive state (on state). The switch 64 may be provided outside the regulator 63, and may be an external component such as a relay.

For example, in a state where the power supply of the apparatus on which the encoder apparatus EC is mounted is not turned on (for example, an abnormal state or a standby state), at least a part of the position detection system 1 (for example, the multi-rotation information detection unit 3) may operate using electric power obtained by rectifying the electric signals generated by the electric signal generation units 31A and 31B.

The multi-rotation information detecting unit 3 includes magnetic sensors 51 and 52 and analog comparators 65 and 66 as the magnetism detecting unit 12. The magnetic force detector 12 detects the magnetic field formed by the magnet 11 using the power supplied from the battery 32. The multi-rotation information detection unit 3 includes a counter 67 as the detection unit 13 shown in fig. 1, and includes a nonvolatile memory 68 as the storage unit 14.

Power supply terminal 51p of magnetic sensor 51 is connected to power supply line PL. The ground terminal 51g of the magnetic sensor 51 is connected to the ground line GL. The output terminal 51c of the magnetic sensor 51 is connected to the input terminal 65a of the analog comparator 65. In the present embodiment, the output terminal 51c of the magnetic sensor 51 outputs a voltage corresponding to the difference between the potential of the 2 nd output terminal 51b shown in fig. 2 (D) and the reference potential. The analog comparator 65 is a comparator that compares the voltage output from the magnetic sensor 51 with a predetermined voltage. Power supply terminal 65p of analog comparator 65 is connected to power supply line PL. The ground terminal 65g of the analog comparator 65 is connected to the ground line GL. The output terminal 65b of the analog comparator 65 is connected to the 1 st input terminal 67a of the counter 67. The analog comparator 65 outputs an H-level signal from the output terminal when the output voltage of the magnetic sensor 51 is equal to or greater than a threshold value, and outputs an L-level signal from the output terminal when the output voltage is less than the threshold value.

The magnetic sensor 52 and the analog comparator 66 are configured similarly to the magnetic sensor 51 and the analog comparator 65. Power supply terminal 52p of magnetic sensor 52 is connected to power supply line PL. The ground terminal 52g of the magnetic sensor 52 is connected to the ground line GL. The output terminal 52c of the magnetic sensor 52 is connected to the input terminal 66a of the analog comparator 66. Power supply terminal 66p of analog comparator 66 is connected to power supply line PL. The ground terminal 66g of the analog comparator 66 is connected to the ground line GL. The output terminal 58b of the analog comparator 66 is connected to the 2 nd input terminal 67b of the counter 67. The analog comparator 66 outputs an H-level signal from the output terminal when the output voltage of the magnetic sensor 52 is equal to or greater than the threshold value, and outputs an L-level signal from the output terminal 66b when the output voltage is less than the threshold value.

The counter 67 counts the multiple rotation information of the rotation shaft SF using the power supplied from the battery 32. The counter 67 includes, for example, a CMOS logic circuit or the like. The counter 67 operates using power supplied through the power supply terminal 67p and the ground terminal 67 g. Power supply terminal 67p of counter 67 is connected to power supply line PL. The ground terminal 67g of the counter 67 is connected to the ground line GL. The counter 67 performs a count process using the voltage supplied via the 1 st input terminal 67a and the voltage supplied via the 2 nd input terminal 67b as control signals.

The nonvolatile memory 68 stores at least a part of the rotational position information (for example, multi-rotation information) detected by the detection unit 13 using the power supplied from the battery 32 (performs a writing operation). The nonvolatile memory 68 stores the result (multi-rotation information) counted by the counter 67 as the rotation position information detected by the detection section 13. Power supply terminal 68p of nonvolatile memory 68 is connected to power supply line PL. The ground terminal 68g of the memory unit 14 is connected to the ground line GL. The storage section 14 of fig. 1 includes a nonvolatile memory 68, and can hold information written during power supply even in a state where power is not supplied.

In the present embodiment, a capacitor 69 is provided between the rectifier assemblies 61 and 62 and the regulator 63. The 1 st electrode 69a of the capacitor 69 is connected to a signal line connecting the rectifying elements 61 and 62 and the control terminal 63a of the regulator 63. The 2 nd electrode 69b of the capacitor 69 is connected to the ground line GL. The capacitor 69 is a so-called smoothing capacitor, and reduces pulsation and a load of the regulator. The constant of the capacitor 69 is set to maintain the supply of electric power from the battery 32 to the detection unit 13 and the storage unit 14, for example, until the detection unit 13 detects the rotational position information and writes the rotational position information in the storage unit 14.

The battery 32 includes a primary battery 36 such as a button-type battery and a rechargeable secondary battery 37. Secondary battery 37 is electrically connected to power supply unit MCE of motor control unit MC. At least part of a period (for example, a main power supply on state) during which the power supply unit MCE of the motor control unit MC can supply electric power, the electric power is supplied from the power supply unit MCE to the secondary battery 37, and the secondary battery 37 is charged with the electric power. During a period in which the power supply unit MCE of the motor control unit MC cannot supply electric power (for example, in a main power supply off state), the supply of electric power from the power supply unit MCE to the secondary battery 37 is stopped.

The secondary battery 37 may be electrically connected to a transmission path of the electric signal from the electric signal generating means 31A and 31B. In this case, the secondary battery 37 can be charged with the electric power of the electric signal from the electric signal generating units 31A, 31B. For example, the secondary battery 37 is electrically connected to the circuit between the rectifying assembly 61 and the regulator 63. In a state where the supply of electric power from power supply unit MCE is stopped, secondary battery 37 can be charged with electric power of the electric signals generated by electric signal generating units 31A, 31B by the rotation of rotation shaft SF. The secondary battery 37 may be charged with electric power generated by the electric signal generating units 31A and 31B when the rotation shaft SF is driven by the motor M to rotate.

In the encoder device EC of the present embodiment, in a state where the supply of electric power from the outside is stopped, it is selected from which of the primary battery 36 and the secondary battery 37 the electric power is supplied to the position detection system 1. The power supply system 2 includes a power supply switch (power supply selection unit, selection unit) 38, and the power supply switch 38 switches (selects) which of the primary battery 36 and the secondary battery 37 supplies power to the position detection system 1. The 1 st input terminal of the power switch 38 is electrically connected to the positive electrode of the primary battery 36, and the 2 nd input terminal of the power switch 38 is electrically connected to the secondary battery 37. The output terminal of the power switch 38 is electrically connected to the input terminal 63b of the regulator 63.

The power switch 38 selects the primary battery 36 or the secondary battery 37 as a battery for supplying electric power to the position detection system 1, for example, based on the remaining capacity of the secondary battery 37. For example, when the remaining capacity of the secondary battery 37 is equal to or greater than the threshold value, the power switch 38 switches to supply the electric power from the secondary battery 37 and not to supply the electric power from the primary battery 36. The threshold is set based on the power consumed by the position detection system 1, and is set to be equal to or higher than the power supplied to the position detection system 1, for example. For example, in a case where the electric power consumed by the position detection system 1 can be supplied by the electric power from the secondary battery 37, the power supply switch 38 switches to supply the electric power from the secondary battery 37 without supplying the electric power from the primary battery 36. Further, when the remaining capacity of the secondary battery 37 is less than the threshold value, the power switch 38 switches to supply no electric power from the secondary battery 37 and to supply electric power from the primary battery 36. The power switch 38 may also serve as a charger for controlling charging of the secondary battery 37, for example, and may determine whether or not the remaining amount of the secondary battery 37 is equal to or greater than a threshold value using information on the remaining amount of the secondary battery 37 used for charging control.

By using the secondary battery 37 in this manner, the consumption of the primary battery 36 can be delayed. Therefore, the encoder device EC does not require maintenance (e.g., replacement) of the battery 32, or the frequency of maintenance is low.

The battery 32 may include at least one of the primary battery 36 and the secondary battery 37. In the above embodiment, electric power is supplied alternatively from the primary battery 36 or the secondary battery 37, but electric power may be supplied in parallel from the primary battery 36 and the secondary battery 37. For example, the processing unit to which the primary battery 36 supplies power and the processing unit to which the secondary battery 37 supplies power may be defined according to the power consumption of each processing unit (for example, the magnetic sensor 51, the counter 67, and the nonvolatile memory 68) of the position detection system 1. The secondary battery 37 may be charged using at least one of the electric power supplied from the power supply unit EC2 and the electric power of the electric signal generated by the electric signal generation units 31A and 31B.

Next, the operations of the power supply system 2 and the multi-rotation information detection unit 3 will be described. Fig. 5 is a timing chart showing the operation of the multi-rotation information detecting unit 3 when the rotation shaft SF rotates counterclockwise (rotates forward). The timing chart showing the operation of the multi-rotation information detecting unit 3 when the rotation axis SF rotates counterclockwise (reverses) is a diagram in which the diagram of fig. 4 is reversed in time, and therefore, the description thereof is omitted.

In the "magnetic field" of fig. 5, a solid line indicates a magnetic field at the position of the 1 st electric signal generating unit 31A, and a broken line indicates a magnetic field at the position of the 2 nd electric signal generating unit 31B. "1 st electric signal generating unit" and "2 nd electric signal generating unit" respectively denote the output of the 1 st electric signal generating unit 31A and the output of the 2 nd electric signal generating unit 31B, and the output of a current flowing in one direction is positive (+) and the output of a current flowing in the opposite direction is negative (-). The "enable signal" indicates a potential applied to the control terminal 63a of the regulator 63 by the electric signals generated by the electric signal generating units 31A, 31B, and indicates a high level with "H" and a low level with "L". "regulator" indicates the output of the regulator 63, and "H" indicates a high level, and "L" indicates a low level.

The "magnetic field at the 1 st magnetic sensor" and the "magnetic field at the 2 nd magnetic sensor" in fig. 5 are magnetic fields formed at the magnetic sensors 51 and 52. The long dashed line indicates the magnetic field formed by the magnet 11, the short dashed line indicates the magnetic field formed by the bias magnet, and the solid line indicates the combined magnetic field. The "1 st magnetic sensor" and the "2 nd magnetic sensor" respectively indicate outputs when the magnetic sensors 51 and 52 are always driven, the output from the 1 st output terminal is indicated by a broken line, and the output from the 2 nd output terminal is indicated by a solid line. "1 st analog comparator" and "2 nd analog comparator" denote outputs from the analog comparators 65 and 66, respectively. The output in the case of driving the magnetic sensor and the analog comparator all the time is shown as "always driven", and the output in the case of driving the magnetic sensor and the analog comparator intermittently is shown as "intermittently driven".

In the case where the rotation shaft SF rotates counterclockwise, the 1 st electric signal generating unit 31A outputs a current pulse ("1 st electric signal generating unit" +) flowing in a forward direction at angular positions of 180 ° and 0 ° (360 °). Further, at angular positions 90 ° and 270 °, the 1 st electric signal generation unit 31A outputs a current pulse flowing in the reverse direction ("of the 1 st electric signal generation unit"). At the angular positions 135 ° and 315 °, the 2 nd electric signal generating unit 31B outputs a current pulse flowing in the reverse direction ("of the 2 nd electric signal generating unit"). Further, at the angular positions 45 ° and 225 °, the 2 nd electric signal generating unit 31B outputs a current pulse ("of the 2 nd electric signal generating unit") flowing in the forward direction. Accordingly, the enable signal switches to the high level at angular positions 45 °, 90 °, 135 °, 180 °, 225 °, 270 °, 315 °, and 0 °, respectively. In addition, regulator 63 supplies a predetermined voltage to power supply line PL at angular positions 45 °, 90 °, 135 °, 180 °, 225 °, 270 °, 315 °, and 0 °, respectively, in response to the state in which the enable signal is maintained at the high level.

In the present embodiment, the output of the magnetic sensor 51 and the output of the magnetic sensor 52 have a phase difference of 90 °, and the detection unit 13 detects the rotational position information using the phase difference. In the range from the angular position 22.5 ° to the angular position 112.5 °, the output of the magnetic sensor 51 is sinusoidal. In this angular range, the regulator 63 outputs electric power at angular positions 45 °, 90 °. The magnetic sensor 51 and the analog comparator 65 are driven by electric power supplied at angular positions 45 ° and 90 °, respectively. The signal output from the analog comparator 65 (hereinafter referred to as an a-phase signal) is maintained at the L level in a state of not receiving power supply, and becomes the H level at angular positions 45 ° and 90 °, respectively.

Further, the output of the magnetic sensor 52 is sinusoidal in the range of angular positions 157.5 ° to 247.5 °. In this angular range, the regulator 63 outputs power at angular positions 180 °, 225 °. The magnetic sensor 52 and the analog comparator 66 are driven by electric power supplied at angular positions 180 ° and 225 °, respectively. The signal output from the analog comparator 66 (hereinafter referred to as a B-phase signal) is maintained at the L level in a state of not receiving power supply, and becomes the H level at angular positions 180 ° and 225 °, respectively.

Here, when the a-phase signal supplied to the counter 67 is at the H level (H) and the B-phase signal supplied to the counter 67 is at the L level, the group of these signal levels is represented in the form of (H, L). In fig. 5, at the angular position 180 °, the set of signal levels is (L, H), at the angular position 225 °, the set of signal levels is (H, H), and at the angular position 270 °, the set of signal levels is (H, L).

When one or both of the detected a-phase signal and B-phase signal are at the H level, the counter 67 causes the storage unit 14 to store a set of signal levels. When one or both of the a-phase signal and the B-phase signal detected next is at the H level, the counter 67 reads the previous level group from the storage unit 14, compares the previous level group with the present level group, and determines the rotation direction.

For example, when the previous set of signal levels is (H, H) and the current set of signal levels is (H, L), the angular position is 225 ° in the previous detection and 270 ° in the current detection, and therefore, the detection is known as counterclockwise (normal rotation). When the current level group is (H, L) and the previous level group is (H, H), the counter 67 supplies an increment signal indicating an increase in the count to the storage unit 14. When the increment signal from the counter 67 is detected, the storage unit 14 updates the stored multi-rotation information to a value incremented by 1. In the case of inversion, the previous signal level is (H, H) and the current signal level is (L, H), and therefore the storage unit 14 subtracts 1 from the multi-rotation information. The multi-rotation information detection unit 3 of the present embodiment can detect multi-rotation information while determining the rotation direction of the rotation shaft SF in this manner. Further, since the electric current is intermittently supplied from the electric signal generating means 31A, 31B to the magnetic sensors 51, 52 only during the generation of the pulse signal, the power consumption of the battery 32 can be greatly suppressed as compared with the case where the electric current is always supplied to the magnetic sensors 51, 52.

Next, an example of a method for manufacturing the encoder device EC according to the present embodiment will be described with reference to a flowchart of fig. 6 (a). Hereinafter, the encoder device EC will be described as an encoder device provided with only 1 electric signal generating unit 31A. The present invention can be manufactured in the same manner even when a plurality of electric signal generating units are provided. First, in step 120 of fig. 6A, the case 6 (including the magnet 11, the yoke member 18, and the like) in which the power generating unit 42A, the magnetic induction unit 41A, the 1 st magnetic body 45A, the 3 rd magnetic body 46A, and the electric signal generating unit 31A shown in fig. 7a are mounted is prepared (for example, manufactured). The case 6 has a short cylindrical shape with an opening 6A at the center, a groove 6b for accommodating the 1 st magnetic body 45A, the 3 rd magnetic body 46A, and the power generating portion 42A is formed in a part of the case 6, and relief grooves 6c for accommodating both ends of the magnetic induction portion 41A are formed in the circumferential side surfaces of the groove 6 b.

In the next step 122, the magnetic induction portion 41A is attached to an inspection tool, not shown, and it is inspected whether or not an electric signal of, for example, a predetermined standard or more can be obtained from the power generation portion 42A. The inspection tool is a finished product of an encoder device EC including the electric signal generating unit 31A as a reference, which can pick and place the magnetic induction portion 41A, for example. The magnetic induction portion 41A that is qualified for inspection is used in step 126. Next, in step 124, the assembly jig 44 shown in fig. 8 (a) and (B) is used. The assembly jig 44 has a rectangular parallelepiped shape, and 2 cylindrical holes 44a and 44d having a diameter slightly larger than the power generation section 42A and a depth slightly shorter than the power generation section 42A are formed in one surface thereof. Holes 44b and 44e, which are slightly larger in diameter than the magnetic induction portion 41A and slightly deeper in thickness than the portions of the magnetic bodies 45A and 46A on the power generation portion 42A side, are formed in the centers of the holes 44a and 44 d. Relief grooves 44c and 44f for allowing both ends of the coil of the power generating section 42A to pass through are formed in a range from the side surfaces of the holes 44a and 44d to the side surface of the assembly jig 44. And, the power generating portion 42A is fitted (inserted) into the hole portion 44d of the assembly jig 44. The other hole 44a is also fitted with another power generation section 42A.

In the next step 126, the magnetically sensitive portion 41A is inserted into the through hole 42Ac of the power generating portion 42A in the hole 44d of the assembly jig 44 shown in fig. 8 (B). The distal end of the magnetic induction portion 41A is inserted into a hole 44e in the hole 44 d. In this state, the magnetically sensitive portion 41A is fixed to the end (mouth) of the through hole 42Ac of the power generating portion 42A at 1 or 2 by adhesion or the like. Thereby, as shown in fig. 8 (C), the power generating portion 42A and the magnetic induction portion 41A are integrated.

In parallel with these operations or before these operations, in step 128, as shown in fig. 7 (B), the yoke member 18 (side yoke 18S) provided with the magnet 11 is disposed inside the housing 6. As shown in fig. 9B, the rotation shaft SF is rotatably supported at the center of the base member 7 (which supports the motor M in fig. 1) via a rotary bearing (not shown), for example. A cylindrical end portion of the disk 5 is fixed to a distal end portion of the rotating shaft SF by a bolt 10, a yoke member 18 (side yoke 18S) is coupled to a bottom surface of the disk 5, and the magnet 11 is disposed in the yoke member 18. In other words, in this example, the disk 5 also serves as the support member. The housing 6 is fixed to the upper surface of the base member 7 by bolts (not shown) at, for example, 3 so as to surround the disk 5 and the magnet 11. Therefore, the case 6 (housing) is disposed so as to surround the side yoke 18S (2 nd magnetic body) and be rotatable relative to the side yoke 18S. Further, as shown in fig. 7 (B), a 1 st magnetic body 45A and a 3 rd magnetic body 46A are attached to the groove portion 6B of the housing 6. The 1 st magnetic body 45A and the 3 rd magnetic body 46A are provided in an upper portion (groove portion 6b) of the case 6. Further, a configuration may be adopted in which the yoke member 18 is not rotated (in this case, the magnet 11 is fixed to the rotation shaft SF or the like via a support member not shown). In this case, the yoke member 18 can be fixed to the case 6.

Next, in step 130, the integrated power generating portion 42A and magnetic induction portion 41A are housed in the groove portion 6b of the case 6. At this time, 2 end portions of the magnetic induction portion 41A protruding from both ends of the power generation portion 42A are accommodated in the notch portions 45Aa and 46Aa of the 1 st magnetic body 45A and the 3 rd magnetic body 46A and the escape groove 6c of the case 6. In the next step 132, the power generation section 42A is fixed to the case 6 by bonding or the like, and both end portions of the coil of the power generation section 42A are connected to the terminals 42Aa and 42Ab by welding or the like. Thereby completing the electric signal generating unit 31A.

Further, in step 134, as shown in fig. 9 (a) and (B), the disc-shaped shielding plate 8 for magnetic force and the sensor substrate 9 on which the angle detection unit 4 and the magnetic force detection unit 12 of fig. 1 are mounted on the upper portion of the housing 6 in which the electric signal generation unit 31A is incorporated, thereby completing the encoder device EC. The shield plate 8 is formed with a notch 8a for accommodating the electric signal generating unit 31A and a rectangular opening 8b through which light from the light emitting portion of the sensor substrate 9 and magnetic lines for the magnetism detecting portion 12 pass. The sensor substrate 9 is provided with a housing portion 9a for housing a battery 32 (e.g., a primary battery) and a housing portion 9b for housing a processing circuit. Further, in step 136, the inspection of the finished product of the encoder device EC is performed. For example, the rotation shaft SF is rotated at a predetermined rotation speed, and whether or not an electric signal of a predetermined specification or more can be obtained from the electric signal generating unit 31A is detected. When the electric signal of a predetermined standard or higher can be obtained from the electric signal generating unit 31A, the encoder device EC is a non-defective product, and the manufacturing process is completed. When the electric signal of a predetermined standard or more is not obtained from the electric signal generating means 31A, the process may return to step 130, for example, to replace the integrated power generating unit 42A and magnetic induction unit 41A. According to this manufacturing method, since the power generating unit 42A and the magnetic induction unit 41A can be efficiently and accurately positioned relative to each other using the assembly jig 44, the electric signal generating unit 31A and the encoder device EC can be efficiently manufactured.

As described above, the encoder device EC of the present embodiment includes: a position detection system 1 (position detection unit) that detects rotational position information of a rotating shaft SF (moving unit) of a motor M (power supply unit); a magnet 11 that rotates in conjunction with the rotation shaft SF and has a plurality of polarities in a rotation direction (θ direction) of the rotation shaft SF; an electric signal generating unit 31A (electric signal generating unit) which has a magnetic induction portion 41A (magnetic induction member 47) whose magnetic characteristics change in accordance with a change in magnetic field generated along with movement of the magnet 11 (rotation axis SF), and a 1 st magnetic body 45A for guiding the magnetic induction of the magnet 11 to the magnetic induction portion 41A, and generates an electric signal based on the magnetic characteristics of the magnetic induction portion 41A; and a side yoke 18S (2 nd magnetic body) disposed between the magnet 11 and the magnetic induction portion 41A, and guiding the magnetic induction of one polarity portion of the magnet 11 to the other polarity portion of the magnet 11.

According to the present embodiment, since the magnetic field component unnecessary for pulse generation (component (noise component) that cancels the necessary magnetic field component) in the electric signal generating unit 31A including the magnetic induction line generated on the side surface of the magnet 11 is returned to the magnet 11 via the side yoke 18S, the unnecessary magnetic field component does not adversely affect generation of a magnetic domain wall from one end to the other end in the longitudinal direction of the magnetic induction portion 41A due to inversion of the alternating magnetic field caused by rotation of the magnet 11. Therefore, even if the magnetic induction portion 41A is disposed near the side yoke 18S (magnet 11) and the electric signal generating means 31A is downsized, it is possible to efficiently and reliably (stably output) a high-output pulse (electric signal) using the electric signal generating means 31A by reversing the axial direction alternating magnetic field generated by the rotation of the magnet 11 without being affected by the unnecessary magnetic field component. In addition, when the encoder apparatus EC includes the battery 32, maintenance (for example, replacement) of the battery 32 can be omitted or the frequency of maintenance of the battery 32 can be reduced by using the electric signal efficiently generated by the electric signal generating unit 31A.

The present inventors actually examined the pulse generated by using the electric signal generating means 31A of the present embodiment, and as a result, found that a stable pulse with small amplitude fluctuation can be obtained when the magnet 11 rotates. This is also considered to be an effect of providing the electric signal generating means 31A with a neutral zone (time 2) in which the magnetic field is substantially 0 in the magnetic induction portion 41A.

In the encoder device EC, electric power is supplied from the battery 32 to the multi-rotation information detecting unit 3 in a short time after the electric signal generating unit 31A generates the electric signal, and the multi-rotation information detecting unit 3 is dynamically driven (intermittently driven). After the detection and writing of the multi-rotation information are completed, the power supply to the multi-rotation information detecting unit 3 is turned off, but the count value is stored in the storage unit 14 and is held. Even in a state where the external power supply is interrupted, such a sequence is repeated every time a predetermined position on the magnet 11 passes near the electric signal generating unit 31A. The multi-rotation information stored in the storage unit 14 is read out from the motor control unit MC and the like at the next start of the motor M, and used to calculate the initial position of the rotating shaft SF. In the encoder device EC, the battery 32 supplies at least a part of the electric power consumed by the position detection system 1 based on the electric signal generated by the electric signal generation unit 31A, so that the battery 32 can be made long-lived. Therefore, maintenance (e.g., replacement) of the battery 32 can be omitted, or the frequency of maintenance can be reduced. For example, when the life of the battery 32 is longer than the life of the other parts of the encoder device EC, the battery 32 can be replaced without.

In addition, when a magnetic induction wire such as a wiegand wire is used, even if the rotation of the magnet 11 is extremely low, the pulse current (electric signal) can be output from the electric signal generating unit 31A. Therefore, for example, even in a state where power is not supplied to the motor M, when the rotation of the rotating shaft SF (magnet 11) is extremely low, the output of the electric signal generating unit 31A can be used as the electric signal. As the magnetic induction wire (magnetic induction portion 41A), an amorphous magnetostrictive wire or the like can be used.

The method for manufacturing the encoder device EC according to the present embodiment includes: a step 120 of preparing the magnetic induction unit 41A, the power generation unit 42A, and the 1 st magnetic body 45A; steps 124 and 126 of inserting the power generation part 42A into the 1 st hole 44d of the assembly jig 44, and inserting the magnetically sensitive part 41A into the 2 nd hole 44e provided in the 1 st hole 44d through the power generation part 42A; a step 126 of fixing the power generation unit 42A and the magnetic induction unit 41A; and a step 132 of fixing the power generation section 42A taken out of the assembly jig 44 to the case 6, the case 6 being disposed on a side surface of the side yoke 18S (2 nd magnetic body). According to this manufacturing method, since the power generating portion 42A and the magnetic induction portion 41A can be easily fixed in a correct positional relationship in the assembly jig 44, the electric signal generating unit 31A and the encoder device EC can be efficiently manufactured.

In addition, a method of incorporating the magnetic induction portion 41A and the power generation portion 42A into the case 6 (housing) for the encoder device EC of the present embodiment is a method of incorporating the magnetic induction portion 41A and the power generation portion 42A into the case 6 of the encoder device EC, and the encoder device EC includes: a position detection system 1 (position detection unit) that detects rotational position information of a rotation shaft SF (movement unit); a magnet 11 that rotates in conjunction with the rotation shaft SF and has a plurality of polarities in a rotation direction (θ direction) of the rotation shaft SF; an electric signal generating unit 31A (electric signal generating unit) having a magnetic induction unit 41A whose magnetic characteristics change in accordance with a change in magnetic field caused by movement of the magnet 11, a power generation unit 42A that generates an electric signal based on the magnetic characteristics of the magnetic induction unit 41A, and a 1 st magnetic body 45A for guiding the magnetic induction of the magnet 11 to the magnetic induction unit 41A; and a side yoke 18S (2 nd magnetic body) disposed between the magnet 11 and the magnetic induction portion 41A, for guiding the magnetic induction of one polarity portion of the magnet 11 to the other polarity portion of the magnet 11. The method comprises the following steps: steps 124 and 126 of inserting power generation unit 42A into 1 st hole 44d of assembly jig 44, and inserting magnetically sensitive portion 31A into 2 nd hole 44e provided in 1 st hole 44d through power generation unit 42A; a step 126 of fixing the power generation unit 42A and the magnetic induction unit 41A; and a step 132 of fixing the power generation section 42A taken out of the assembly jig 44 to the case 6, the case 6 being disposed on a side surface of the side yoke 18S (2 nd magnetic body). According to this incorporation method, the power generating portion 42A and the magnetic induction portion 41A can be easily fixed in a correct positional relationship in the assembly jig 44, and therefore, the electric signal generating unit 31A can be efficiently manufactured.

The present embodiment can be modified as follows.

In the above embodiment, 2 electric signal generating units 31A and 31B are provided, but the encoder device EC may be provided with only 1 electric signal generating unit 31A. Further, the encoder device EC may include 3 or more electric signal generating units. In other embodiments and modifications thereof described below, 1 electric signal generating means is described, but a plurality of electric signal generating means may be provided.

In the method of manufacturing the encoder device EC or the method of incorporating the magnetic induction portion 41A and the power generation portion 42A into the housing 6, as shown in the modification of fig. 6B, the power generation portion 42A may be mounted on the inspection tool (not shown) in step 140 after step 120 (preparation step). Further, in step 142, a magnetic induction portion 41A (not shown) (main magnetic induction portion) for preliminary inspection may be inserted into the through hole 42Ac of the power generation portion 42A to check whether or not an electric signal of, for example, a predetermined specification or more can be obtained from the power generation portion 42A, and the magnetic induction portion 41A may be a reference for confirming generation of an appropriate electric signal from the power generation portion 42A when the power generation portion 42A (not shown) is inserted. The power generation unit 42A is inspected by this inspection. The power generation unit 42A that has been inspected to be acceptable is attached to the assembly jig 44 in step 124 of fig. 6 (a). The subsequent manufacturing process is the same as the operation of fig. 6 (a). According to this modification, the inspection of the power generation unit 42A is completed, and therefore the yield in the inspection of the finished product in step 136 is improved.

As shown in the modification of fig. 10, after step 120 (preparation step), the power generation unit 42A may be attached to the hole 44d of the assembly jig 44 in step 124, the magnetic induction unit 41A may be inserted into the power generation unit 42A in step 144, and the power generation unit 42A and the magnetic induction unit 41A integrated in the assembly jig 44 may be attached to an inspection tool (not shown) in step 146. In this example, in step 148, 2 terminals of the coil of the power generation unit 42A may be connected to electrodes (not shown) of an inspection tool to inspect whether or not an electric signal of, for example, a predetermined standard or higher can be obtained from the power generation unit 42A. The power generating portion 42A and the magnetic induction portion 41A that have passed the inspection are fixed to the hole (e.g., the tip) of the through-hole 42Ac by bonding or the like. Then, the connection is removed, and the process proceeds to step 132 in fig. 6 (a), where the integrated power generating portion 42A and magnetic induction portion 41A are attached to the case 6. The subsequent operation is the same as the operation of fig. 6 (a). According to this modification, the inspection of the power generating portion 42A and the magnetic induction portion 41A is integrally completed, and therefore, the yield in the product inspection at step 136 can be improved.

[ 2 nd embodiment ]

Embodiment 2 will be described with reference to fig. 11 (a) to 12 (C). In fig. 11 (a) to 12 (C), the same reference numerals are given to the parts corresponding to fig. 2 (a) to (C), and detailed description thereof is omitted.

Fig. 11 (a) is a perspective view showing a magnet 11A, a yoke member 18A, and an electric signal generating unit 31C of the encoder device of the present embodiment, fig. 11 (B) is a plan view showing the encoder device, and fig. 11 (C) is a side view of fig. 11 (B). In fig. 11 (a) and (B), the magnet 11A is configured such that the direction and intensity of the magnetic field in the radial direction (or radial direction ) AD2 with respect to the rotation axis SF change according to the rotation. The magnet 11A is formed of, for example, a plurality of annular magnets arranged coaxially with the rotation axis SF. The main surface (front surface) and the back surface of the magnet 11A are substantially perpendicular to the rotation axis SF.

The magnet 11A includes a 1 st group magnet and a 2 nd group magnet, the 1 st group magnet being configured by 4 magnets of N pole 16E, S pole 16F, N pole 16G and S pole 16H, each having a rectangular parallelepiped shape and having the same shape, being arranged in an annular shape at 90 ° intervals in the rotation direction or circumferential direction (θ direction) of the rotation shaft SF; the group 2 magnets are arranged in a ring shape so as to be in close contact with the inner surfaces of the group 1 magnets, and each of the group 2 magnets includes a magnet having an S-pole 17E, N, a pole 17F, S, a pole 17G, and an N-pole 17H of the same shape. The phases of the outer-peripheral 1 st group magnet and the inner-peripheral 2 nd group magnet are shifted by 180 °. In this manner, the magnet 11A has a plurality of (4 in this example) polarities (the N pole 16E, S, the pole 16F, and the like) in the θ direction. In the magnet 11A, a direction orthogonal to the rotation direction (movement direction), that is, a radial direction (radial direction) AD2 with respect to the rotation axis SF in the present embodiment is considered to be the width direction of the magnet 11A. At this time, the magnet 11A also has different polarities (N pole 16E, S pole 17E, etc.) in the width direction (radial direction AD2) orthogonal to the θ direction on the front surface or the back surface. As the magnet 11A, a permanent magnet magnetized to have a plurality of pairs (e.g., 4 pairs) of polarities in the θ direction, for example, an annular band shape may be used. For example, a member including the N-pole 16E and the S-pole 17E can be regarded as one magnet element magnetized to have 2 magnetic poles. The magnetization direction (orientation direction) of the magnet 11A of the present embodiment is a radial direction (radial direction) AD 2.

The yoke member 18A made of a ferromagnetic material includes a back yoke 18AB having an annular shape and an opening 18Aa, on which the magnet 11A is mounted, and a side yoke 18AS having a cylindrical shape and disposed so AS to surround the magnet 11A on the back yoke 18 AB. However, in the side yoke 18AS of the present embodiment, a plurality of (4 in this example) openings 18Ab, 18Ac, 18Ad, and 18Ae are provided at the same positions AS the portions having different polarities (the N pole 16E, the S pole 16F, and the like) in the circumferential direction of the magnet 11A at the same angular intervals AS the angular intervals θ T of the portions having different polarities. The width of the openings 18Ab to 18Ae is substantially the same as the width of the magnets of the N-pole 16E to S-pole 16H, and the magnets of the N-pole 16E to S-pole 16H face the side surface of the magnet 11 in the direction (radial direction) perpendicular to the rotation axis SF.

In the present embodiment, the magnetic induction member 47 of the electric signal generating unit 31C is disposed in the vicinity of the outer side surface of the side yoke 18AS such that the longitudinal direction LD1 is parallel to the circumferential direction of the rotation shaft SF. Therefore, the electric signal generating unit 31C can be miniaturized. However, in the present embodiment, the magnetic induction lines of the magnet 11A can be prevented from leaking to the magnetic induction member 47 side by the side yoke 18AS, and therefore, the direction of the longitudinal direction LD1 of the magnetic induction member 47 is arbitrary.

Further, the front end portion 45Cb of the 1 st magnetic body 45C on the one end side of the magnetic induction component 47 is arranged substantially parallel to the outer side surface of the side yoke 18AS in the vicinity of the outer side surface. Further, the distal end portion 46Cb of the 3 rd magnetic body 46C on the other end side of the magnetic induction component 47 is disposed substantially parallel to the outer side surface of the side yoke 18AS in the vicinity of the outer side surface. The tip end portion 45Cb of the 1 st magnetic body 45C and the tip end portion 46Cb of the 3 rd magnetic body 46C are formed axially symmetrically so AS to extend in a "chevron shape, and the angular interval between the tip end portion 45Cb and the tip end portion 46Cb is substantially the same AS the angular interval θ T of the openings 18Ab to 18Ae of the side yoke 18AS (i.e., the angular interval of mutually different polarity portions of the magnet 11A). In other words, the leading end portion 45Cb of the 1 st magnetic body 45C and the leading end portion 46Cb of the 3 rd magnetic body 46C are paired, and the leading end portions 45Cb, 46Cb are formed in directions (outward) away from each other with respect to the axisymmetric reference line. The other configurations are the same as those of embodiment 1.

In the present embodiment, AS shown in fig. 11B, when the center of the electric signal generating unit 31C is located at the middle position or the vicinity position of the mutually different polarity portions (for example, the N-pole 16E and the S-pole 16F) of the magnet 11A, the front end portions 45Cb, 46Cb of the 1 st magnetic body 45C and the 3 rd magnetic body 46C face the mutually different polarity portions of the magnet 11A through the openings (for example, the openings 18Ac, 18Ab) of the side yoke 18 AS. A magnetic circuit MC5 including magnetic induction lines oriented in the longitudinal direction of the magnetic induction portion 41A is formed by the magnet 11A, the 1 st magnetic body 45C, the magnetic induction member 47 (magnetic induction portion 41A), and the 3 rd magnetic body 46C. Further, unnecessary magnetic induction lines extending from the N-pole 16E located close to the magnetic induction member 47 in a direction inclined with respect to the radial direction of the rotation shaft SF (the direction of the magnetic induction member 47) are directed toward the adjacent S-pole 16F along the magnetic path MC6 formed in the side yoke 18 AS. Therefore, the magnetic induction lines generated in the oblique direction from the N-pole 16E and the like do not face the longitudinal direction of the magnetic induction portion 41A, and the magnetic induction lines in the opposite direction that cancel the original magnetic induction lines do not work in the longitudinal direction of the magnetic induction portion 41A.

Fig. 12 (B) shows a state in which the magnet 11A and the yoke member 18A are rotated 45 ° counterclockwise from the state of fig. 11 (B), fig. 12 (a) shows a perspective view of the state, and fig. 12 (C) is a side view of fig. 12 (B). In fig. 12 (B), the center or the vicinity of the N-pole 16E is located at the center of the electric signal generating unit 31C via the opening 18Ab of the side yoke 18AS, and the front end portions 45Cb, 46Cb of the 1 st magnetic body 45C and the 3 rd magnetic body 46C of the electric signal generating unit 31C are located in the vicinity of the outer side surface of the side yoke 18 AS. Therefore, the magnetic induction lines from the N-pole 16E toward the 1 st magnetic body 45C and the 3 rd magnetic body 46C (in the radial direction of the rotating shaft SF) are guided to the adjacent S-poles 16F and 16H via the magnetic circuit MC6 of the side yoke 18AS, and do not face the magnetic induction component 47. Similarly, when the center or the vicinity of the center of the S pole 16F, N, 16G, S, 16H is located at the center of the electric signal generating unit 31C, the magnetic induction line extending from the S pole 16F, N, 16G, S, 16H in the radial direction of the rotation axis SF is also guided to the portion of the other polarity via the side yoke 18AS, and therefore, the magnetic induction line is not guided in the longitudinal direction of the magnetic induction member 47. Therefore, no induced current is generated in the magnetic induction member 47.

AS shown in fig. 11B and 12B, when the magnetic body 11 is positioned at least at one angular position within 1 rotation of the magnet 11 (for example, an angular position at which the electric signal is generated from the electric signal generating units 31A and 31B), the front end portions 45Cb and 46Cb (the inclination angles of the front end portions 45Cb and 46Cb are determined) are arranged so that the center line CL2a of the front end portion 45Cb of the 1 st magnetic body 45C and the center line CL2B of the front end portion 46Cb of the 3 rd magnetic body 46C are substantially parallel to the side yokes 18AS on both sides of the predetermined polar portion (the N-pole 16E in fig. 12B) or the predetermined opening (the opening 18Ab in fig. 12B) of the magnet 11 when viewed in the axial direction of the rotation shaft SF. At least one angular position within 1 rotation of the magnet 11A, the tip end portion 45Cb of the 1 st magnetic element 45C is disposed at a position facing a predetermined polarity portion (N pole 16E to S pole 16H) of the magnet 11A in the radial direction (radial direction) of the rotation axis SF. At least a part of the 1 st magnetic body 45C and the 3 rd magnetic body 46C is disposed at a position overlapping the side yoke 18AS in the radial direction of the rotation shaft SF.

AS described above, in the electric signal generating unit 31C of the present embodiment, the 1 st time (the period centered on the time point (B) in fig. 11) when the magnetic induction line from the magnet 11A passes through the opening of the side yoke 18AS and the 1 st and 3 rd magnetic bodies 45C and 46C and passes through the magnetic induction portion 41A and the 2 nd time (the period centered on the time point (B) in fig. 12) when the magnetic induction line from the magnet 11A passes through the side yoke 18AS (the 2 nd magnetic body) and does not pass through the magnetic induction portion 41A also have the 1 st time and the 2 nd time when the electric signal is generated by the electric signal generating unit 31A at the 1 st time. The interval of the magnet 11A at the time 2 (interval of a predetermined angle of 1 rotation) is a neutral interval (at the time 2) in which the magnetic field is substantially 0 in the magnetic induction portion 41A.

Therefore, according to the electric signal generating unit 31C of the present embodiment, the change in the magnetic induction line in the longitudinal direction of the magnetic induction portion 41A is drastic by switching from the 2 nd time, which is a period in which the magnetic induction line from the magnet 11A does not pass through the longitudinal direction of the magnetic induction member 47 shown in (B) of fig. 12, to the 1 st time, which is a period in which the magnetic induction line from the magnet 11A passes through the opening of the side yoke 18AS and the 1 st magnetic body 45C and the 3 rd magnetic body 46C of the magnetic bodies pass through the longitudinal direction of the magnetic induction member 47 shown in (B) of fig. 11, to the 1 st time, which is a pulse with a higher output from the power generating portion 42A, by the rotation of the magnet 11A and the yoke member 18A.

Further, since the magnetic induction line of the magnet 11A does not leak outside the outer side surface of the side yoke 18AS during the period centered on the time 2, even if the magnetic induction member 47 is disposed close to the outer side surface of the side yoke 18AS and the distance between the magnetic induction member 47 and the magnet 11A is narrowed, a high-output electric signal can be obtained from the magnetic induction member 47. Therefore, the electric signal generating unit 31C can be miniaturized while obtaining a high-output pulse.

[ embodiment 3 ]

Embodiment 3 will be described with reference to (a) and (B) of fig. 13. In fig. 13(a) and (B), the same reference numerals are given to the parts corresponding to fig. 2 (a) to (C), and detailed description thereof is omitted.

Fig. 13(a) is a plan view showing the magnet 11B, the yoke member 18, and the electric signal generating unit 31D of the encoder device according to the present embodiment, and fig. 13 (B) is a plan view showing a state in which the magnet 11B is rotated counterclockwise by 45 ° from the state in fig. 13 (a). In fig. 13(a), the magnet 11B is placed on the back yoke 18B of the yoke member 18 so that the direction and intensity of the magnetic field in the Axial direction (Axial direction) parallel to a straight line passing through the center of the rotation axis SF change due to the rotation. The magnet 11B is surrounded by the side yoke 18S. The magnet 11B is composed of: 1 pairs of rectangular flat plate-like N poles 16I and 16K arranged symmetrically with the rotation axis SF interposed therebetween; magnets of S poles 16J and 16L of the same shape located at positions where the N poles 16I and 16K are rotated by 90 ° around the rotation axis SF; and magnets (not shown) of the south poles 17I, 17K and the north poles 17J, 17L having the same shape and arranged on the back surfaces of the north poles 16I, 16K and the south poles 16J, 16L, respectively.

The magnet 11B is a combination of a plurality of (4 in fig. 13 a) permanent magnets magnetized to have 4 pairs of polarities in the circumferential direction (θ direction) around the rotation axis SF. The magnet 11B may be formed of 1 ring-shaped magnet, and the N pole 16I to S pole 16L and the like may be magnetized to the magnet. The main surface of the magnet 11B, i.e., the front surface (the surface on the opposite side of the motor M in fig. 1) and the back surface are substantially perpendicular to the rotation axis SF. As the magnet 11B rotates, an alternating magnetic field is formed in which the direction of the magnetic field in the axial direction is reversed. The electric signal generating unit 31D is disposed on the upper surface and the outer surface of the magnet 11B when viewed from the normal direction of the main surface of the magnet 11B.

In the present embodiment, the main body portion (portion including the magnetic induction member 47) of the electric signal generating unit 31D is provided so as to be away from the magnet 11B in the radial direction (radial direction) orthogonal to the rotation axis SF or in the direction parallel to the radial direction, and so as not to contact the magnet 11B. The electric signal generating unit 31D includes a magnetic induction member 47, a 1 st magnetic body 45A, and a 3 rd magnetic body 46A. The 1 st magnetic body 45A and the 3 rd magnetic body 46A are provided so as to straddle the side yoke 18S between the surface of the magnet 11B and both ends of the magnetic induction portion 41A. The longitudinal direction of the magnetic induction member 47 is substantially parallel to the circumferential direction of the rotation shaft SF, for example, and therefore, the electric signal generating unit 31D can be downsized.

As shown in fig. 13B, when the magnet 11 is located at least one angular position within 1 rotation of the magnet (for example, an angular position at which the electric signal is generated from the electric signal generating units 31A and 31B), the tip portions 45Ab and 46Ab are arranged (the inclination angles of the tip portions 45Ab and 46Ab are determined) such that the center line CL1A of the tip portion 45Ab of the 1 st magnetic body 45A and the center line CL1B of the tip portion 46Ab of the 3 rd magnetic body 46A are substantially parallel to both sides (both side surfaces) of the adjacent 2 polar portions (the N pole 16I and the S pole 16L in fig. 13B) of the magnet 11B on the side of the electric signal generating unit 31D, when viewed in the axial direction of the rotation shaft SF. The 1 st magnetic body 45A is disposed at a position facing a predetermined polarity portion (N pole 16I to S pole 16L) of the magnet 11B in the axial direction of the rotation shaft SF or in a direction parallel thereto at least at 1 angular position within 1 rotation of the magnet 11B. At least a part of the 1 st magnetic body 45A and the 3 rd magnetic body 46A is disposed at a position overlapping with the predetermined polarity portion (the N pole 16I to the S pole 16L) of the magnet 11B and the side yoke 18S, respectively, when viewed in the axial direction of the rotation shaft SF.

As shown in fig. 13 a, when the center of the N-pole 16I (or the S-pole 16J, N, 16K, S, 16L) of the magnet 11B or the vicinity thereof is located at the same angular position as the center of the electric signal generating unit 31D, the magnet 11B-side tip portions 45Ab, 46Ab of the 1 st magnetic body 45A and the 3 rd magnetic body 46A are inclined inward symmetrically so as to be substantially parallel to the 2 symmetrical sides of the magnet of the N-pole 16I and to be spaced outward from the 2 sides. In this state, the magnetic induction line of the N pole 16N is directed to the other polarity (S poles 16J, 16L, 17I) portion via the side yoke 18AS, and is not directed to the magnetic induction member 47 via the front end portions 45Ab, 46 Ab. Therefore, a neutral zone (time 2) in which the magnetic field component in the longitudinal direction of the magnetic induction portion 41A is substantially 0 can be set in a wider angle range than in the case of fig. 3 (B).

As shown in fig. 13B, when the magnet 11B is rotated by 45 ° from the state of fig. 13 a, the center of the north pole 16I and the south pole 16L (or the center of the south pole 16L and the north pole 16K, the center of the north pole 16K and the south pole 16J, or the center of the south pole 16J and the north pole 16I) or the vicinity thereof of the magnet 11 is located at the same angular position as the center of the electric signal generating unit 31D. In this state, the tip portions 45Ab, 46Ab of the 1 st magnetic body 45A and the 3 rd magnetic body 46A on the magnet 11B side are substantially parallel to and above the 2 opposing sides of the magnets of the N-pole 16I and the S-pole 16L. Therefore, the magnetic induction wire of the N pole 16I is guided to the S pole 16L through the 1 st magnetic body 45A, the magnetic induction portion 41A, and the 3 rd magnetic body 46A, and magnetic domain walls are formed in the longitudinal direction of the magnetic induction portion 41A (time 1). When the magnet 11B is rotated by 90 °, the direction of the domain wall in the magnetic induction portion 41A is reversed. At this time, in the present embodiment, since the neutral zone is wide, the magnetic field in the magnetic induction portion 41A is rapidly inverted by the rotation of the magnet 11B, and a pulse with a higher output can be generated from the magnetic induction member 47 more stably.

[ 4 th embodiment ]

Embodiment 4 will be described with reference to the flowchart of fig. 14 and (a) and (B) of fig. 15. In fig. 14 and 15 (a) and (B), the same reference numerals are given to the parts corresponding to fig. 6 (a) and 9 (a), and detailed description thereof is omitted. The encoder device of the present embodiment has substantially the same configuration as the encoder device EC of embodiment 1. However, as shown in fig. 15 (a), a cutout 6d is provided near a portion of the side surface of the case 6 in which the 1 st magnetic body 45A and the 3 rd magnetic body 46A are housed, and a lateral hole 6e, which is a through hole for inserting the magnetic sensor 41A, is formed in a side wall of the cutout 6 d.

An example of a method of manufacturing the encoder device of the present embodiment and a method of assembling the magnetic induction portion 41A and the power generation portion 42A to the case 6 (housing) for the encoder device will be described below. First, in step 128 subsequent to step 120 (preparation step) in fig. 14, as shown in fig. 15 a, the yoke member 18 (side yoke 18S) provided with the magnet 11 is disposed inside the case 6. In the next step 150, the 1 st magnetic body 45A and the 3 rd magnetic body 46A are attached to the groove 6b (see fig. 7a) of the housing 6. Further, in step 152, the power generation section 42A is fitted to the groove 6b (between the 1 st magnetic body 45A and the 3 rd magnetic body 46A) of the case 6, and the power generation section 42A is fixed to the case 6 by adhesion or the like. Both ends of the coil of the power generation unit 42A are connected to the terminals 42Aa and 42 Ab.

In the next step 154, as shown in fig. 15 a, the magnetic induction portion 41A is inserted into the through hole 42Ac (see fig. 7a) of the power generation portion 42A via the notch portion 6d and the lateral hole 6e of the case 6. In the present embodiment, the magnetic induction portion 41A can be inserted into the power generation portion 42A from the side surface direction, and therefore, circular openings may be provided in the portions of the 1 st magnetic body 45A and the 3 rd magnetic body 46A on the power generation portion 42A side, instead of the elongated cutout portions 45Aa and 46Aa (see fig. 2A). In this state, in step 156, it is checked whether or not the power generation unit 42A and the magnetic induction unit 41A can rotate the rotation shaft SF (magnet 11) and obtain a pulse having a size not smaller than a predetermined standard from the power generation unit 42A. When a pulse of a predetermined standard or more can be obtained, both ends of the magnetic induction portion 41A are fixed to the case 6 by adhesion or the like in step 158. Thereby, the electric signal generating unit 31A is completed.

Next, at step 160, as shown in fig. 15 (B), the shield plate 8 is attached to the housing 6. Further, at step 134 of fig. 6a, the sensor substrate 9 is mounted, and the finished product is inspected (step 136), thereby completing the encoder device EC. According to the present embodiment, the present invention includes: step 152 of fixing the power generation unit 42A to the case 6, the case 6 being disposed on the side surface of the side yoke 18S (2 nd magnetic body); step 154, inserting the magnetic induction part 41A into the power generation part 42A through a transverse hole 6e (opening) provided in the case 6; and step 158, fixing the magnetic induction part 41A to the housing 6. By inserting and fixing the magnetic induction portion 41A into the power generation portion 42A of the housing 6 in this manner, the power generation portion 42A and the magnetic induction portion 41A can be efficiently assembled as compared with the case of using the assembly jig 44, and the electric signal generation unit 31A and the encoder device can be efficiently manufactured.

In the case where a plurality of electric signal generating units are provided as in the above-described embodiment, the electric power output from the electric signal generating unit 31A may be used as a detection signal for detecting multi-rotation information, or may be used for supplying to a detection system or the like.

In embodiment 1, the magnet 11 is a magnet having 4 poles in the circumferential direction and 8 poles having 2 poles in the thickness direction, but the configuration is not limited to this, and can be modified as appropriate. For example, the number of poles of the magnet 11 in the circumferential direction may be 2 or 4 or more.

In the above embodiment, the position detection system 1 detects the rotational position information of the rotating shaft SF (moving part) as the position information, but may detect at least one of the position, the velocity, and the acceleration in a predetermined direction as the position information. The encoder device EC may comprise a rotary encoder or a linear encoder. The encoder device EC may be an encoder device in which the power generation unit and the detection unit are provided on the rotation axis SF, the magnet 11 is provided outside the moving body (for example, the rotation axis SF), and the relative position between the magnet and the detection unit changes with the movement of the moving unit. The position detection system 1 may not detect the multi-rotation information of the rotation axis SF, or may detect the multi-rotation information by a processing unit outside the position detection system 1.

In the above embodiment, the electric signal generating means 31A and 31B generate electric power (electric signal) when they are in a predetermined positional relationship with the magnet 11. The position detection system 1 may detect the position information of the moving part (for example, the rotation axis SF) by using the change in the electric power (signal) generated in the electric signal generation units 31A and 31B as the detection signal. For example, the electric signal generating units 31A and 31B may be used as sensors, and the position detecting system 1 may detect the position information of the moving part by the electric signal generating units 31A and 31B and 1 or more sensors (e.g., magnetic sensors and light receiving sensors). In the case where the number of the electric signal generating units is 2 or more, the position detection system 1 may detect the position information using 2 or more electric signal generating units as sensors. For example, the position detection system 1 may detect the position information of the moving part without using a magnetic sensor or may detect the position information of the moving part without using a light receiving sensor, using 2 or more electric signal generating units as sensors.

The electric signal generating units 31A and 31B may supply at least a part of the electric power consumed by the position detection system 1. For example, the electric signal generating units 31A and 31B may supply electric power to a processing unit having relatively small electric power consumption in the position detection system 1. The power supply system 2 may not supply power to a part of the position detection system 1. For example, the power supply system 2 may intermittently supply power to the detection unit 13 without supplying power to the storage unit 14. In this case, power may be intermittently or continuously supplied to the storage unit 14 from a power supply, a battery, or the like provided outside the power supply system 2. The power generation unit may be a power generation unit that generates power by a phenomenon other than the large barkhausen jump, and may not supply power to the moving unit (for example, the rotating shaft SF) and a part of the position detection system 1, for example. For example, the power supply system 2 may intermittently supply power to the detection unit 13 without supplying power to the storage unit 14. In this case, power may be intermittently or continuously supplied to the storage unit 14 from a power supply, a battery, or the like provided outside the power supply system 2. The power generation unit may generate power by using a phenomenon other than the large barkhausen jump, and may generate power by electromagnetic induction caused by a change in magnetic field accompanying the movement of the moving unit (e.g., the rotating shaft SF), for example. The storage unit for storing the detection result of the detection unit may be provided outside the position detection system 1 or outside the encoder device EC.

[ Driving device ]

An example of the driving device will be described. Fig. 16 is a diagram showing an example of the drive device MTR. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. The drive unit MTR is a motor unit including an electric motor. The drive device MTR includes a rotary shaft SF, a main body (drive unit) BD for rotationally driving the rotary shaft SF, and an encoder device EC for detecting rotational position information of the rotary shaft SF.

The rotating shaft SF has a load side end portion SFa and a counter load side end portion SFb. The load side end SFa is connected to another power transmission mechanism such as a speed reducer. A scale S is fixed to the counter load side end SFb via a fixing portion. An encoder device EC is attached together with the fixation of the scale S. The encoder device EC is an encoder device of the above-described embodiment, modification, or combination thereof. For example, the encoder device includes an optical detection unit that illuminates the scale S with illumination light from the light emitting element 21Aa, and detects angle information by detecting light from the scale S with the light receiving sensors 21Ab and 21 Ac.

In the drive device MTR, the motor control unit MC shown in fig. 1 controls the main body BD using the detection result of the encoder device EC. In the drive device MTR, the battery of the encoder device EC does not need to be replaced, or the necessity of battery replacement is low, so that the maintenance cost can be reduced. The drive unit MTR is not limited to the motor unit, and may have another drive unit that rotates a shaft by hydraulic pressure or pneumatic pressure.

[ Table device ]

An example of the table device will be described. Fig. 17 shows the table device STG. The table device STG is configured such that a rotary table (moving object) ST is attached to a load-side end portion SFa of a rotation shaft SF of the drive device MTR shown in fig. 16. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

When the rotation shaft SF is rotated by driving the driving device MTR in the table device STG, the rotation is transmitted to the turntable ST. At this time, the encoder device EC detects the angular position of the rotation shaft SF, and the like. Therefore, the angular position of the rotary table ST can be detected by using the output from the encoder device EC. Further, a speed reducer or the like may be disposed between the load-side end portion SFa of the drive device MTR and the turntable ST.

In the table device STG, the necessity of replacing the battery of the encoder device EC is low or the battery does not need to be replaced, so that the maintenance cost can be reduced. The table device STG is applicable to, for example, a rotary table or the like provided with a machine tool such as a rotary table.

[ robot device ]

An example of the robot device will be described. Fig. 18 is a perspective view showing the robot apparatus RBT. In addition, a part (joint part) of the robot apparatus RBT is schematically shown in fig. 18. In the following description, the same or equivalent components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. The robot RBT includes a 1 st arm AR1, a 2 nd arm AR2, and a joint JT. The 1 st arm AR1 is connected to the 2 nd arm AR2 via a joint JT.

The 1 st arm AR1 includes a wrist portion 101, a bearing 101a, and a bearing 101 b. The 2 nd arm AR2 includes the wrist 102 and the connection part 102 a. The connection portion 102a is disposed between the bearing 101a and the bearing 101b at the joint portion JT. The connection portion 102a is provided integrally with the rotation shaft SF 2. The rotation shaft SF2 is inserted into both the bearing 101a and the bearing 101b at the joint JT. The end of the rotary shaft SF2 on the side where the bearing 101b is inserted penetrates the bearing 101b and is connected to the reduction gear RG.

The reduction gear RG is connected to the drive unit MTR, and reduces the rotation of the drive unit MTR to, for example, one percent and transmits the rotation to the rotation shaft SF 2. Although not shown in fig. 18, a load-side end portion SFa of the rotating shaft SF of the drive device MTR is connected to the reduction gear RG. Further, a scale S of the encoder device EC is attached to a counter load side end portion SF of the rotation shaft SF of the drive device MTR.

In the robot apparatus RBT, when the rotation shaft SF is rotated by driving the driving device MTR, the rotation is transmitted to the rotation shaft SF2 through the speed reducer RG. The rotation of the rotation shaft SF2 rotates the connection unit 102a integrally, and thereby the 2 nd arm AR2 rotates relative to the 1 st arm AR 1. At this time, the encoder device EC detects the angular position of the rotation shaft SF, and the like. Therefore, the angular position of the 2 nd arm AR2 can be detected based on the output from the encoder device EC.

In the robot apparatus RBT, since the necessity of replacing the battery of the encoder apparatus EC is eliminated or reduced, the maintenance cost can be reduced. The robot apparatus RBT is not limited to the above configuration, and the drive unit MTR can be applied to various robot apparatuses including joints.

Description of the reference numerals

A 1 … position detecting system, A3 … multi-rotation information detecting part, a 4 … angle detecting part, a 5 … disk, 11A … magnet, a 12 … magnetic force detecting part, a 13 … detecting part, a 14 … storing part, 18S, 18AS … side yoke, a 21 … light emitting element (irradiating part), a 22 … light receiving sensor (light detecting part), 31A, 31B … electric signal generating unit, 32 … battery, 33 … switching part, 36 … primary battery, 37 … secondary battery, 41a … magnetic induction part, 42a … power generation part, 43A, 43B … box, 45a … 1 st magnetic body, 46a … 3 rd magnetic body, 47 … magnetic induction part, 51, 52 … magnetic sensor, 63 … regulator, 64 … switch, 67 … counter, EC … encoder device, SF … rotation shaft, AR1 … 1 st arm, AR2 … 2 nd arm, MTR … driving device, RBT … manipulator device, STG … table device.

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