阅读说明：本技术 旋转角度传感器 (Rotation angle sensor ) 是由 关富勇治 今枝宏旨 田中浩则 于 2018-10-26 设计创作，主要内容包括：旋转角度传感器的转子(2)将磁性钢板的带状主体(31)的厚度方向作为径向方向地将带状主体(31)形成为圆筒状。在带状主体(31)的一个圆弧状的边缘部以大致固定的节距设有第1凹凸部(32),并且在另一个圆弧状的边缘部以大致固定的节距设有第2凹凸部(33)。与转子(2)的带状主体(31)的第1凹凸部(32)相对地配设第1定子(3),与第2凹凸部(33)相对地配设第2定子(4)。(A rotor (2) of a rotation angle sensor is formed by cylindrically forming a band-shaped body (31) of a magnetic steel plate with the thickness direction of the band-shaped body (31) as the radial direction. A1 st uneven portion (32) is provided at a substantially constant pitch at one arc-shaped edge portion of the belt-shaped main body (31), and a 2 nd uneven portion (33) is provided at a substantially constant pitch at the other arc-shaped edge portion. A1 st stator (3) is disposed so as to face a 1 st uneven portion (32) of a belt-shaped main body (31) of a rotor (2), and a 2 nd stator (4) is disposed so as to face a 2 nd uneven portion (33).)

1. A rotation angle sensor is characterized in that,

the rotation angle sensor includes:

a 1 st stator in which an excitation winding and an output winding are wound around a plurality of 1 st stator magnetic poles arranged in an annular shape;

a 2 nd stator formed by winding an excitation winding and an output winding around a plurality of 2 nd stator magnetic poles arranged in an annular shape; and

a rotor disposed inside or outside the 1 st stator and the 2 nd stator with a gap therebetween so as to be rotatable,

in the rotor, a band-shaped main body of a magnetic steel plate is formed in a cylindrical shape with a thickness direction of the band-shaped main body as a radial direction, 1 st concave-convex portions are provided at substantially constant pitches at one arc-shaped edge portion of the band-shaped main body, and 2 nd concave-convex portions are provided at substantially constant pitches at the other arc-shaped edge portion,

the 1 st stator is opposite to the inner or outer peripheral surface of the 1 st concavo-convex part of the belt-shaped main body, a plurality of 1 st stator magnetic poles are arranged in a row at fixed intervals in the circumferential direction,

the 2 nd stator is opposed to an inner peripheral surface or an outer peripheral surface of the 2 nd concave-convex portion of the belt-like body of the rotor, and a plurality of 2 nd stator magnetic poles are arranged at fixed intervals in a circumferential direction.

2. The rotation angle sensor according to claim 1,

the band-shaped body of the rotor is formed by bending a single layer of magnetic steel plate into a cylindrical shape, and is formed such that the outer circumferential surface of the band-shaped body faces the outside of the rotor and the inner circumferential surface of the band-shaped body faces the inside of the rotor.

3. The rotation angle sensor according to claim 1,

the band-shaped body of the rotor is formed by bending a plurality of laminated magnetic steel plates into a cylindrical shape.

4. The rotation angle sensor according to claim 1,

the 1 st concave-convex portion and the 2 nd concave-convex portion are formed in a substantially sine wave shape.

5. The rotation angle sensor according to claim 1,

the pitch of the 1 st concave-convex portion and the pitch of the 2 nd concave-convex portion are different from each other and formed corresponding to different shaft double angles.

6. The rotation angle sensor according to claim 1,

the rotor is configured by fitting a synthetic resin circular ring portion to the outer periphery of the rotating shaft and attaching the band-shaped body to the outer periphery of the synthetic resin circular ring portion.

7. The rotation angle sensor according to claim 6,

the 1 st stator and the 2 nd stator are arranged outside the rotor with a gap therebetween.

8. The rotation angle sensor according to claim 6,

the 1 st stator is disposed inside the rotor with a gap therebetween, and the 2 nd stator is disposed outside the rotor with a gap therebetween.

9. The rotation angle sensor according to claim 1,

the cylindrical rotor is rotatably disposed outside the 1 st stator and outside the 2 nd stator, and the 1 st stator and the 2 nd stator are disposed inside the rotor with a gap therebetween.

10. A rotation angle sensor is characterized in that,

the rotation angle sensor includes:

a 1 st stator in which an excitation winding and an output winding are wound around a plurality of 1 st stator magnetic poles arranged in an annular shape;

a 2 nd stator formed by winding an excitation winding and an output winding around a plurality of 2 nd stator magnetic poles arranged in an annular shape; and

a rotor disposed inside or outside the 1 st stator and the 2 nd stator with a gap therebetween so as to be rotatable,

in the rotor, a rotor main body is formed in a cylindrical shape by a magnetic steel material, annular recesses having a uniform depth are continuously formed in a circumferential direction on an outer circumferential surface or an inner circumferential surface of the rotor main body, 1 st concave-convex portions are provided at substantially constant pitches on one arc-shaped edge portion of the annular recesses, and 2 nd concave-convex portions are provided at substantially constant pitches on the other arc-shaped edge portion,

the 1 st stator is opposed to the inner peripheral surface or the outer peripheral surface of the 1 st uneven portion of the annular concave portion, a plurality of 1 st stator magnetic poles are arranged at regular intervals in the circumferential direction,

the 2 nd stator is opposed to the inner peripheral surface or the outer peripheral surface of the 2 nd uneven portion of the annular recess, and a plurality of 2 nd stator magnetic poles are arranged at fixed intervals in the circumferential direction.

11. A rotation angle sensor is characterized in that,

the rotation angle sensor includes:

a 1 st stator in which an excitation winding and an output winding are wound around a plurality of 1 st stator magnetic poles arranged in an annular shape;

a 2 nd stator formed by winding an excitation winding and an output winding around a plurality of 2 nd stator magnetic poles arranged in an annular shape; and

a rotor disposed inside or outside the 1 st stator and the 2 nd stator with a gap therebetween so as to be rotatable,

in the rotor, a rotor main body is formed in a cylindrical shape by a magnetic steel material, annular convex portions having a uniform thickness are continuously formed in a circumferential direction on an outer circumferential surface or an inner circumferential surface of the rotor main body, 1 st concave-convex portions are provided at substantially constant pitches on one arc-shaped edge portion of the annular convex portions, and 2 nd concave-convex portions are provided at substantially constant pitches on the other arc-shaped edge portion,

the 1 st stator is opposed to the inner peripheral surface or the outer peripheral surface of the 1 st uneven portion of the annular convex portion, a plurality of 1 st stator magnetic poles are arranged in a row at a fixed interval in the circumferential direction,

the 2 nd stator is opposed to the inner peripheral surface or the outer peripheral surface of the 2 nd concave-convex portion of the annular convex portion, and a plurality of 2 nd stator magnetic poles are arranged at a fixed interval in the circumferential direction.

12. A rotation angle sensor is characterized in that,

the rotation angle sensor includes:

a 1 st stator in which an excitation winding and an output winding are wound around a plurality of 1 st stator magnetic poles arranged in an annular shape;

a 2 nd stator formed by winding an excitation winding and an output winding around a plurality of 2 nd stator magnetic poles arranged in an annular shape;

a 3 rd stator formed by winding an excitation winding and an output winding on a plurality of 3 rd stator poles arranged in an annular shape;

a 4 th stator in which an excitation winding and an output winding are wound around a plurality of 4 th stator magnetic poles arranged in an annular shape; and

a rotor disposed rotatably inside the 1 st stator and inside the 2 nd stator and outside the 3 rd stator and outside the 4 th stator with a gap therebetween,

in the rotor, a rotor main body is formed in a cylindrical shape by a magnetic steel material, a 1 st annular recess portion having a uniform depth is continuously formed in an outer peripheral surface of the rotor main body in a circumferential direction, a 2 nd annular recess portion having a uniform depth is continuously formed in an inner peripheral surface of the rotor main body in a circumferential direction, a 1 st concave-convex portion is provided at an arc-shaped edge portion of the 1 st annular recess portion at a substantially fixed pitch, a 2 nd concave-convex portion is provided at a substantially fixed pitch at another arc-shaped edge portion, the 1 st concave-convex portion is provided at an arc-shaped edge portion of the 2 nd annular recess portion at a substantially fixed pitch, and the 2 nd concave-convex portion is provided at a substantially fixed pitch at another arc-shaped edge portion,

the 1 st stator is opposed to the outer peripheral surface of the 1 st uneven portion of the 1 st annular recess, a plurality of 1 st stator poles are arranged in a row at fixed intervals in the circumferential direction,

the 2 nd stator is opposite to the outer peripheral surface of the 2 nd concave-convex part of the 1 st annular concave part, a plurality of 2 nd stator magnetic poles are arranged in a row at fixed intervals in the circumferential direction,

the 3 rd stator is opposite to the outer peripheral surface of the 1 st concavo-convex part of the 2 nd annular concave part, a plurality of 3 rd stator magnetic poles are arranged in a row at fixed intervals in the circumferential direction,

the 4 th stator faces the outer peripheral surface of the 2 nd concave-convex portion of the 2 nd annular concave portion, and a plurality of 4 th stator magnetic poles are arranged at fixed intervals in the circumferential direction.

Technical Field

The present invention relates to a variable reluctance type rotation angle sensor, and more particularly, to a rotation angle sensor that can be miniaturized.

Background

As a rotation angle sensor for detecting a rotation angle of a motor or the like, a variable reluctance type rotation angle sensor is widely used in many fields. This rotation angle sensor is configured in such a manner that: a plurality of magnetic poles are provided on the inner peripheral side of an annular stator yoke, an excitation winding and a detection winding are wound around each magnetic pole as a stator winding, and a core-type rotor is disposed inside the stator with a gap therebetween. An SIN winding and a COS winding for detection having a phase difference of 90 DEG are wound around each magnetic pole of a stator as a winding for detection.

The rotation angle sensor generates an SIN signal and a COS signal corresponding to the rotation angle of the rotor in the SIN winding and the COS winding for output by supplying an alternating current to the excitation winding, and outputs the signals. The SIN signal and the COS signal are R/D converted, and the rotation angle data and the absolute angle data of the rotor are calculated based on the converted digital data.

However, the rotor of the conventional variable reluctance type rotation angle sensor is generally configured by laminating a large number of magnetic steel plates in the axial direction of the rotor, as described in, for example, patent document 1 below, and the large number of magnetic steel plates are formed in a shape in which a plurality of salient poles are provided so as to protrude from the outer peripheral portion, and therefore the shape thereof is increased. In addition, when a plurality of rotors are disposed in the axial direction and a plurality of stators are disposed corresponding to the respective rotors in order to provide the redundant function to the rotation angle sensor, the rotation angle sensor is further increased in size.

Disclosure of Invention

Problems to be solved by the invention

In addition, although the conventional rotation angle sensor is configured to have the outer shape of each salient pole on the outer periphery of the rotor in order to obtain an appropriate sine wave from the output winding of the stator in accordance with the rotation of the rotor, the conventional rotation angle sensor has a problem that the overall shape of the rotation angle sensor is increased in size because the conventional rotation angle sensor is configured by laminating a large number of magnetic steel plates.

The present invention has been made to solve the above-described problems, and an object thereof is to provide a rotation angle sensor that can be made compact and can be manufactured at low cost.

Means for solving the problems

The rotation angle sensor of the present invention is characterized in that,

the rotation angle sensor includes:

a 1 st stator in which an excitation winding and an output winding are wound around a plurality of 1 st stator magnetic poles arranged in an annular shape;

a 2 nd stator formed by winding an excitation winding and an output winding around a plurality of 2 nd stator magnetic poles arranged in an annular shape; and

a rotor disposed inside or outside the 1 st stator and the 2 nd stator with a gap therebetween so as to be rotatable,

in the rotor, a band-shaped main body of a magnetic steel plate is formed in a cylindrical shape with a thickness direction of the band-shaped main body as a radial direction, 1 st concave-convex portions are provided at substantially constant pitches at one arc-shaped edge portion of the band-shaped main body, and 2 nd concave-convex portions are provided at substantially constant pitches at the other arc-shaped edge portion,

the 1 st stator is opposite to the inner or outer peripheral surface of the 1 st concavo-convex part of the belt-shaped main body, a plurality of 1 st stator magnetic poles are arranged in a row at fixed intervals in the circumferential direction,

the 2 nd stator is opposed to an inner peripheral surface or an outer peripheral surface of the 2 nd concave-convex portion of the belt-like body of the rotor, and a plurality of 2 nd stator magnetic poles are arranged at fixed intervals in a circumferential direction.

The magnetic steel sheet is a high-permeability material that generates a magnetic flux or a magnetic flux density necessary for detecting the rotation angle of the rotor when a magnetic field is applied, and examples thereof include non-oriented electrical steel sheets, non-oriented silicon steel sheets, stainless steel, structural carbon steel, soft magnetic alloys such as Fe — Ni alloys, permalloy such as Fe — Al alloys and Fe — Co alloys, amorphous metals, and ferrites such as FeO, CoO, and ZnO. The cylindrical band-shaped body is formed by bending a plate material, die forming, casting, cutting, or the like.

According to the rotation angle sensor of the present invention, the band-shaped body of the rotor is formed with the 1 st uneven portion and the 2 nd uneven portion at both side edge portions of the band-shaped magnetic steel plate, and can be formed only by bending into a cylindrical shape or only by processing such as die forming, and therefore can be manufactured at a very low cost.

Further, compared to a conventional rotor having salient poles protruding in the radial direction (radial direction), the overall shape of the rotor can be made smaller, and the rotation angle sensor can be made smaller. Further, since the 1 st stator and the 2 nd stator are included, when any one of the stators is erroneously detected due to a failure or the like, a redundant function can be provided by using a detection signal from the other stator.

Here, the band-shaped body of the rotor may be formed by molding a single layer of magnetic steel plate into a cylindrical shape, and the band-shaped body may be formed such that an outer circumferential surface of the band-shaped body faces the outside of the rotor and an inner circumferential surface of the band-shaped body faces the inside of the rotor. Further, a plurality of laminated magnetic steel sheets may be bent into a cylindrical shape.

Here, it is also preferable that the 1 st concave-convex portion and the 2 nd concave-convex portion are formed in a substantially sine wave shape. Thus, a good SIN wave signal or COS wave signal can be obtained from each output winding of the 1 st stator magnetic pole and the 2 nd stator magnetic pole.

It is also preferable that the pitch of the 1 st concave-convex portion and the pitch of the 2 nd concave-convex portion are formed differently, and the pitch of the 1 st concave-convex portion and the pitch of the 2 nd concave-convex portion are formed corresponding to different shaft double angles. Thus, the rotor is simply provided with portions having different shaft double angles, and two kinds of output signals having different output shaft double angles can be output from the respective output windings of the 1 st stator magnetic pole and the 2 nd stator magnetic pole without applying a special winding method to the respective output windings of the 1 st stator magnetic pole and the 2 nd stator magnetic pole, and the signals are R/D converted, thereby obtaining the absolute rotation angle signal relatively easily.

The rotor may be configured such that a synthetic resin circular ring portion is fitted to an outer periphery of the rotating shaft, and a belt-shaped body is attached to an outer periphery of the synthetic resin circular ring portion. This makes it possible to easily attach the band-shaped body of the rotor to an accurate position.

ADVANTAGEOUS EFFECTS OF INVENTION

The rotation angle sensor according to the present invention can be miniaturized and can be manufactured at low cost.

Drawings

Fig. 1 is a perspective view showing a rotation angle sensor according to embodiment 1 of the present invention.

Fig. 2a and 2B are perspective views of the rotor of the rotation angle sensor.

Fig. 3 is a developed view of the band-shaped body of the rotor.

Fig. 4 is an explanatory diagram showing a relationship between the stator and the rotor.

Fig. 5 is a perspective view of the rotor attached to the rotating shaft.

Fig. 6 is a block diagram of a signal processing circuit.

Fig. 7 is a graph showing a relationship between the rotation angle of the rotor, the R/D conversion output data value of the sensor, and the absolute angle data value.

Fig. 8 is a flowchart when calculating the absolute angle θ a.

Fig. 9 is a perspective view of the rotation angle sensor according to embodiment 2.

Fig. 10 is a longitudinal sectional view of the rotation angle sensor.

Fig. 11 is a plan view of the rotation angle sensor with a section.

Fig. 12 is a perspective view of an outer rotor type rotation angle sensor according to embodiment 3.

Fig. 13 is a graph showing a detected angle error with respect to a mechanical angle.

Fig. 14 a is a longitudinal sectional view of the rotation angle sensor according to embodiment 4, and fig. 14B is a partial perspective view of a rotor body thereof.

Fig. 15 a is a perspective view of a rotor body having an annular recessed portion formed on an outer peripheral surface thereof, fig. 15B is a perspective view of a rotor body having an annular recessed portion formed on an inner peripheral surface thereof, and fig. 15C is a perspective view of a rotor body having an annular projecting portion formed on an outer peripheral surface thereof.

Fig. 16 is a waveform diagram of an output voltage signal with respect to a mechanical angle of the rotor.

Fig. 17 is a graph showing a detected angle error with respect to a mechanical angle.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 to 5 show a rotation angle sensor according to embodiment 1. The rotation angle sensor includes: the stator includes a 1 st stator 3 in which an excitation winding and an output winding are wound around a plurality of 1 st stator poles 11 arranged in an annular shape, a 2 nd stator 4 in which an excitation winding and an output winding are wound around a plurality of 2 nd stator poles 16 arranged in an annular shape, and a rotor 2 arranged rotatably inside the 1 st stator 3 and inside the 2 nd stator 4 with a gap therebetween.

As shown in fig. 2, the rotor 2 is formed by bending a strip-shaped body 31 of magnetic steel plate into a cylindrical shape with the thickness direction of the strip-shaped body 31 as the radial direction (radial direction). That is, the band-shaped body 31 is rolled into a cylindrical shape with one flat surface as the inside and the other flat surface as the outside, and both end portions thereof are connected by welding or the like to form a cylindrical shape. Thereby, the outer peripheral surface 31a of the band-shaped body 31 faces the outside of the rotor 2, and the inner peripheral surface 31b thereof faces the inside of the rotor 2. As shown in fig. 3, the belt-like body 31 has a 1 st uneven portion 32 at a fixed pitch at one arc-like edge portion and a 2 nd uneven portion 33 at a fixed pitch at the other arc-like edge portion.

The magnetic steel plates of the strip-shaped body 31 may be non-oriented electrical steel plates, and iron alloys such as Fe — Al alloys and Fe — Co alloys, which are high-permeability materials that generate magnetic fluxes or magnetic flux densities necessary for detecting the rotation angle of the rotor 2 when a magnetic field is applied.

Here, as shown in fig. 3, a sine wave shaped portion is formed as a 1 st concave-convex portion 32 on the upper portion of the band-shaped main body 31, and 5 rotor magnetic poles are formed in a convex shape so as to form a rotor of an axis multiplier (english) "5X" on the upper portion. In addition, a sinusoidal wave portion is also formed as the 2 nd concave-convex portion 33 in the lower portion of the belt-shaped main body 31, and 6 rotor magnetic poles are formed in a convex shape so as to form a rotor having an axis double angle "6X" in the lower portion. The axial multiple angle is a ratio of an output electrical angle of the rotation angle sensor to an input mechanical angle, and when n × mechanical angle θ 1 is equal to electrical angle θ 2, the axial multiple angle is represented by "nX". n is a natural number.

The shape of the 1 st concave-convex portion 32 and the shape of the 2 nd concave-convex portion 33 may be substantially a sine wave shape, a rectangular pulse shape, a sawtooth pulse shape, or an arc-shaped waveform, in addition to a sine wave (cosine wave) shape which is accurate in physical properties.

Further, it is possible to form the respective concavities and convexities at a fixed pitch P1 and a pitch P2 as shown in fig. 3, and the 1 st concave-convex portion 32 and the 2 nd concave-convex portion 33 are formed at pitches P1, P2 corresponding to the respective shaft double angles. Note that the pitch P1 of the 1 st concave-convex portion 32 and the pitch P2 of the 2 nd concave-convex portion 33 may not be strictly fixed in physical characteristics as long as they are substantially fixed pitches. As shown in fig. 2B, two or three or more magnetic steel sheets may be stacked to form the band-shaped body 31.

As shown in fig. 5, the rotor 2 formed of such a band-shaped body 31 is attached to the rotary shaft 9 via a synthetic resin circular ring portion 34. The cylindrical rotor 2 may be attached to the outer peripheral surface of the molded synthetic resin annular portion 34 in close contact therewith, or the rotor 2 may be inserted into a molding die and insert-molded when the synthetic resin annular portion 34 is injection-molded. Therefore, the rotor 2 can be easily attached, and the rotor 2 can be attached to the rotary shaft 9 with accurate positioning. Further, since the rotor 2 having a cylindrical outer shape is formed, the outer shape of the rotor 2 can be inevitably made smaller than that of a conventional rotor having a convex shape in the radial direction.

As shown in fig. 1 and 4, the stator 1 is configured by disposing and fixing annular 1 st stator 3 and 2 nd stator 4 in parallel at a slight interval along the axial direction of the rotating shaft 9 to a fixing portion, not shown. The 1 st stator magnetic pole 11 of the 1 st stator 3 and the 2 nd stator magnetic pole 16 of the 2 nd stator 4 are respectively composed of 14 poles, for example, and the 1 st stator magnetic pole 11 and the 2 nd stator magnetic pole 16 composed of 14 poles are respectively arranged with the respective magnetic poles facing inward at equal intervals.

As shown in fig. 4, the 1 st stator magnetic pole 11 is formed by providing a stator core 12 of each magnetic pole protruding from the inside of an annular stator yoke and winding a stator winding 13 around each of the convex stator cores 12 of each magnetic pole. Similarly, the 2 nd stator pole 16 is formed by providing a stator core 17 of each pole protruding from the inside of an annular stator yoke and winding a stator winding 18 around the convex stator core 17 of each pole.

As shown in fig. 1, the stator windings 13 and 18 of the respective magnetic poles are each composed of an output winding for detection composed of an SIN winding and a COS winding which are shifted from each other in phase, and the terminals of the stator winding 13 of the respective magnetic poles of the 1 st stator magnetic pole 11 are drawn from the connection portion toward the upper side in fig. 1, and the terminals of the stator winding 18 of the respective magnetic poles of the 2 nd stator magnetic pole 16 are drawn from the connection portion toward the lower side. The excitation windings of the stator windings 13 and 18 are connected to an excitation power supply circuit that supplies, for example, an ac current of about 10 kHz. The SIN and COS windings of the output windings of the stator windings 13 and 18 output the SIN and COS output signals as the rotor 2 rotates, and their output terminals are connected to the input sides of the R/D converters 21 and 22, respectively, as shown in fig. 6.

The excitation current and voltage may be, for example, currents and voltages of about 0.2Arms and 7Vrms, which are used in a normal rotation angle sensor. In addition, the thickness of the strip-shaped body 31 of the rotor 2 may be reduced to, for example, about 0.5mm, and in this case, a magnetic path and a magnetic flux density necessary for angle detection can be formed in the rotor 2, and an excitation power supply used in a general rotation angle sensor can be used without being affected by the angle detection operation, such as an eddy current loss due to excitation.

As shown in fig. 1 and 4, the inner end of the stator core 12 of the 1 st stator magnetic pole 11 of the 1 st stator 3 is disposed at a position facing the 1 st concave-convex portion 32 of the rotor 2, and the inner end of the stator core 17 of the 2 nd stator magnetic pole 16 of the 2 nd stator 4 is disposed at a position facing the 2 nd concave-convex portion 33 of the rotor 2.

Accordingly, when the rotor 2 rotates, the 1 st uneven portion 32 and the 2 nd uneven portion 33 move in the circumferential direction, and the overlapping area where the 1 st stator magnetic pole 11 of the 1 st stator 3 overlaps the stator core 12 and the 1 st uneven portion 32 with a gap therebetween changes similarly to the conventional change in gap permeability. Similarly, the overlapping area where the stator core 17 of the 2 nd stator magnetic pole 16 of the 2 nd stator 4 overlaps the 2 nd uneven portion 33 with a gap therebetween changes similarly to the change in the conventional gap permeability.

With this configuration, a common rotor can be formed by only one rotor 2, and a rotation angle sensor capable of outputting detection signals of different shaft multiple angles of the shaft multiple angle "5X" and the shaft multiple angle "6X" can be provided. Thus, the belt-like body 31 is simply formed in a curved shape into a cylindrical shape, and the rotor 2 has a small shape, so that the occupied space occupied by the rotor 2 becomes extremely small, and the entire rotation angle sensor can be downsized.

Further, as shown in fig. 3, the absolute angular position of the rotating shaft 9 can be detected from output (detection) signals of two kinds of axial multiple angles obtained from the 1 st stator magnetic pole 11 and the 2 nd stator magnetic pole 16, regardless of the configuration of the stator 1, because the absolute angular position is formed by the different axial multiple angles of the pitch P1 of the 1 st concave-convex portion 32 on the upper side of the rotor 2 and the pitch P2 of the concave-convex portion 33 on the lower side thereof.

As shown in fig. 6, the signal processing circuit 20 is mainly configured by a CPU23 that performs an operation of arithmetic processing of an angle signal based on program data stored in advance in the memory 25, and two R/D converters 21 and 22 are connected to the input side of the signal processing circuit 20. The R/D converters 21 and 22 convert detection signals, for example, sinusoidal detection signals, transmitted from the output windings of the stator windings 13 and 18, into triangular wave signals having the same period, sample the triangular wave signals, convert the triangular wave signals into digital signals, and output the digital signals.

As shown in fig. 7, the detection signal output from the 1 st stator 3 facing the 1 st concave-convex portion 32 of the rotor 2 becomes, for example, an angle signal θ 2 of the shaft multiple angle "5X", the detection signal output from the 2 nd stator 4 facing the 2 nd concave-convex portion 33 becomes, for example, an angle signal θ 1 of the shaft multiple angle "6X", and the absolute angle θ a of the rotor 2, that is, the rotation shaft 9 is calculated from the two detection signals (angle signals).

That is, as shown in fig. 8, the CPU23 of the signal processing circuit 20 calculates the absolute angle θ a of the rotor 2, that is, the rotary shaft 9, from the relationship between the angle signal θ 1 of the shaft multiple angle "6X" output from the 2 nd stator 4 and the angle signal θ 2 of the shaft multiple angle "5X" output from the 1 st stator 3. As shown in fig. 6, the CPU23 of the signal processing circuit 20 stores the calculated absolute angle data and the like in the memory 25, and outputs the data to the outside via the input/output circuit 24.

Next, the operation of the rotation angle sensor configured as described above will be described with reference to fig. 7 and 8. When the rotating shaft 9 rotates, an alternating current excitation current is supplied to the 1 st stator magnetic pole 11 of the 1 st stator 3 and the 2 nd stator magnetic pole 16 of the 2 nd stator 4, and an alternating current magnetic field is generated in each of the 1 st stator magnetic pole 11 and the 2 nd stator magnetic pole 16.

At this time, the 1 st uneven portion 32 of the rotor 2 rotating together with the rotating shaft 9 and formed at the shaft multiple angle "5X" of the upper edge portion passes through the 1 st stator magnetic poles 11 of the 1 st stator 3, and the 2 nd uneven portion 33 of the shaft multiple angle "6X" of the lower edge portion passes through the 2 nd stator magnetic pole 16. At this time, the magnetic flux generated by each 1 st stator magnetic pole 11 of the 1 st stator 3 is influenced by the 1 st uneven portion 32 facing each 1 st stator magnetic pole 11 of the 1 st stator 3 on the upper portion of the rotor 2, and the magnetic flux generated by each 2 nd stator magnetic pole 16 of the 2 nd stator 4 is influenced by the 2 nd uneven portion 33 facing each 2 nd stator magnetic pole 16 of the 2 nd stator 4 on the lower portion of the rotor 2.

Therefore, an angle signal indicating the detection angle θ 2 of the shaft multiple angle "5X" is output from the output winding of the 1 st stator magnetic pole 11 of the 1 st stator 3, and an angle signal indicating the detection angle θ 1 of the shaft multiple angle "6X" is output from the output winding of the 2 nd stator magnetic pole 16. The angle signals indicating the detected angles θ 1 and θ 2 are sent to the R/D converters 21 and 22, and the R/D converters 21 and 22 convert the angle signals into triangular wave signals, further sample and convert the triangular wave signals into digital signals, and output the digital signals to the signal processing circuit 20.

As shown in fig. 8, the CPU23 first receives the angle data signal of the detection angle θ 2 indicating the axial multiple angle "5X" of the 1 st stator magnetic pole 11 transmitted from the R/D converters 21, 22 in step 100, and receives the angle data signal of the detection angle θ 1 indicating the axial multiple angle "6X" of the 2 nd stator magnetic pole 16 in step 110.

Next, the CPU23 determines whether or not the received detection angle θ 1 of the axis multiple angle "6X" is equal to or greater than the detection angle θ 2 of the axis multiple angle "5X" at step 120, and proceeds to step 130 when the detection angle θ 1 of the axis multiple angle "6X" is equal to or greater than the detection angle θ 2 of the axis multiple angle "5X", and subtracts the detection angle θ 2 of the axis multiple angle "5X" from the detection angle θ 1 of the axis multiple angle "6X", thereby calculating the absolute angle θ a of the rotor 2.

On the other hand, when the CPU23 determines in step 120 that the detection angle θ 1 of the shaft multiple angle "6X" is smaller than the detection angle θ 2 of the shaft multiple angle "5X", the routine proceeds to step 140, and 360 degrees is added to the value obtained by subtracting the detection angle θ 2 of the shaft multiple angle "5X" from the detection angle θ 1 of the shaft multiple angle "6X", thereby calculating the absolute angle θ a of the rotor 2.

In this way, the absolute angle of the rotor 2 can be obtained relatively easily by R/D converting the two kinds of output signals having different winding output shaft double angles from the 1 st stator magnetic pole 11 of the 1 st stator 3 and the 2 nd stator magnetic pole 16 of the 2 nd stator 4.

Fig. 13 shows an error of a detected angle with respect to a rotation angle (mechanical angle) of the rotor 2 when the rotation angle sensor having the above-described configuration is manufactured in a trial and performance test. As shown in fig. 13, although the detection angle error periodically varies depending on the 1 st concave-convex portion 32 and the 2 nd concave-convex portion 33 with respect to each mechanical angle, the error range is in a range that does not cause any problem in actual use.

In the above embodiment, the 1 st concave-convex portion 32 corresponding to the shaft multiple angle "5X" is formed at one edge portion of the rotor 2, the 2 nd concave-convex portion 33 corresponding to the shaft multiple angle "6X" different in pitch is formed at the other edge portion, and the absolute angle θ a of the rotor 2 is detected from the detection angle θ 2 of the shaft multiple angle "5X" and the detection angle θ 1 of the shaft multiple angle "6X", but concave-convex portions having the same shaft multiple angle, that is, concave-convex portions having the same pitch may be formed at both edge portions of the rotor.

In the case where the both edge portions of the rotor form the concavo-convex portions of the same shaft multiple angle, that is, the concavo-convex portions of the same pitch, the same angle detection signals are output from the 1 st stator magnetic pole of the 1 st stator and the 2 nd stator magnetic pole of the 2 nd stator. Therefore, when the rotor has a failure in one stator, which is formed by the concave-convex portions having the same axial multiple angle at both edge portions of the rotor, that is, the concave-convex portions having the same pitch, the angle detection signal output from the stator magnetic pole of the other stator is used, whereby the rotation angle sensor can be used with a redundant function.

Fig. 9 to 11 show a rotation angle sensor according to embodiment 2. As shown in fig. 9, the rotation angle sensor includes the rotor 2 and the 2 nd stator 4 similar to those of the above embodiments, and the 2 nd stator 4 is disposed outside the rotor 2 with a gap therebetween. On the other hand, the 1 st stator 40 is disposed inside the rotor 2. In fig. 9 to 11, the same portions as those of the above embodiment are denoted by the same reference numerals as those of the above embodiment, and the description thereof is omitted.

The rotation angle sensor of this embodiment is an outer rotor type in which the rotor 2 is disposed outside the 1 st stator 40, and is also an inner rotor type in which the rotor 2 is disposed inside the 2 nd stator 4. As shown in fig. 10, the rotation shaft 9 is rotatably supported via a bearing 37 inside a housing 38 as a fixing member, a 1 st concave-convex portion 32 is provided at an upper edge portion of a belt-shaped main body 31 of the rotor 2, and a 2 nd concave-convex portion 33 is provided at a lower edge portion of the belt-shaped main body 31 of the rotor 2. The cylindrical rotor 2 is attached to the vicinity of the corner of the large diameter portion of the rotating shaft 9 via a synthetic resin circular portion 35 and rotates.

As shown in fig. 10, the 2 nd stator 4 of the stator is fixed to the inside of the case 38 with a gap therebetween outside the rotor 2, and the 2 nd stator pole 16 of the 2 nd stator 4 is disposed so as to face the 2 nd concave-convex portion 33 provided at the lower edge portion of the rotor 2. On the other hand, the 1 st stator 40 is disposed inside the rotor 2 and fixed to a fixing member extending inward from the housing 38. The 1 st stator pole 41 of the 1 st stator 40 is disposed inside the 1 st concave-convex portion 32 of the upper edge portion of the rotor 2 so as to face the 1 st concave-convex portion 32 with a gap therebetween. Further, a synthetic resin annular portion 36 is attached to the outside of the upper edge portion of the rotor 2, and the rotor 2 is stably held by the rotary shaft 9.

The 1 st stator magnetic pole 41 of the 1 st stator 40 is composed of, for example, 12 poles, and the 1 st stator magnetic pole 41 composed of 12 poles is disposed with each magnetic pole facing the outer rotor 2 side at equal intervals. The 1 st stator pole 41 is formed by providing a stator core of each magnetic pole protruding from the outside of an annular stator yoke and winding a stator winding around each of the convex stator cores of each magnetic pole.

The rotation angle sensor operates in the same manner as in the above-described embodiment, and when the rotating shaft 9 rotates, an ac excitation current is supplied to the 1 st stator pole 41 of the 1 st stator 40 and the 2 nd stator pole 16 of the 2 nd stator 42, and an ac magnetic field is generated in each of the 1 st stator pole 41 and the 2 nd stator pole 16.

At this time, the 1 st uneven portion 32 of the rotor 2 rotating together with the rotating shaft 9 and formed at the shaft multiple angle "5X" of the upper edge portion passes through the 1 st stator magnetic poles 41 of the 1 st stator 40, and the 2 nd uneven portion 33 of the shaft multiple angle "6X" of the lower edge portion passes through the 2 nd stator magnetic pole 16. At this time, the magnetic flux generated by each 1 st stator pole 41 of the 1 st stator 40 is influenced by the 1 st uneven portion 32 facing each 1 st stator pole 41 of the 1 st stator 40 on the upper portion of the rotor 2, and the magnetic flux generated by each 2 nd stator pole 16 of the 2 nd stator 4 is influenced by the 2 nd uneven portion 33 facing each 2 nd stator pole 16 of the 2 nd stator 4 on the lower portion of the rotor 2.

Therefore, an angle signal indicating the detection angle θ 2 of the shaft multiple angle "5X" is output from the output winding of the 1 st stator pole 41 of the 1 st stator 40, and an angle signal indicating the detection angle θ 1 of the shaft multiple angle "6X" is output from the output winding of the 2 nd stator pole 16.

Fig. 12 shows an outer rotor type rotation angle sensor according to embodiment 3. The rotation angle sensor has a rotor 2 outside the stator, a 1 st stator 40 disposed inside the rotor 2, and a 2 nd stator 42 disposed below the 1 st stator 40. Although not shown, the 1 st stator 40 and the 2 nd stator 42 are fixed to a fixed member, and the rotor 2 is configured by arranging a cup-shaped rotating member so as to cover the outer side of the 1 st stator 40 and the outer side of the 2 nd stator 42 to be rotatable and holding the rotor 2 inside the rotating member.

The rotor 2 is configured by providing a large diameter portion in a part of the rotation shaft, fixing a cup portion made of synthetic resin to an upper edge portion of the large diameter portion, and fixing the band-shaped body 31 to the cup portion, as in the example shown in fig. 10. The cylindrical rotor 2 has a 1 st uneven portion 32 provided at an upper edge portion of a belt-shaped body 31 and a 2 nd uneven portion 33 provided at a lower edge portion thereof. The rotation shaft of the rotor 2 is rotatably supported via a bearing inside the housing, and the 1 st stator 40 and the 2 nd stator 42 are fixed to a fixing member provided inside the housing. As shown in fig. 12, the 1 st stator magnetic pole 41 of the 1 st stator 40 is disposed to face the 1 st concavo-convex portion 32 of the belt-shaped main body 31, and the 2 nd stator magnetic pole 43 of the 2 nd stator 42 is disposed to face the 2 nd concavo-convex portion 33.

That is, the 1 st stator magnetic pole 41 is disposed inside the 1 st concave-convex portion 32 of the upper edge portion of the rotor 2 so as to face the 1 st concave-convex portion 32 of the upper edge portion of the rotor 2 with a gap therebetween, the 2 nd stator 42 is disposed below the 1 st stator 40 and inside the rotor 2 so as to face the rotor 2 with a gap therebetween, and the 2 nd stator magnetic pole 43 of the 2 nd stator 42 is disposed so as to face the 2 nd concave-convex portion 33 provided at the lower edge portion of the rotor 2.

The 1 st stator magnetic pole 41 of the 1 st stator 40 is composed of, for example, 12 poles, and the 1 st stator magnetic pole 41 composed of 12 poles is disposed with each magnetic pole facing the outer rotor 2 side at equal intervals. The 1 st stator pole 41 is formed by providing a stator core of each magnetic pole protruding from the outside of an annular stator yoke and winding a stator winding around each of the convex stator cores of each magnetic pole.

Similarly, the 2 nd stator magnetic pole 43 of the 2 nd stator 42 is also constituted by, for example, 12 poles, and the 2 nd stator magnetic pole 43 constituted by 12 poles is disposed with each magnetic pole facing the outer rotor 2 side at equal intervals. The 2 nd stator pole 43 is formed by projecting a stator core of each pole outside an annular stator yoke and winding a stator winding around the convex stator core of each pole.

In the same manner as in the above-described embodiment, when the rotor 2 rotates, the rotational angle sensor supplies an alternating current excitation current to the 1 st stator magnetic pole 41 of the 1 st stator 40 and the 2 nd stator magnetic pole 43 of the 2 nd stator 42, and generates an alternating current magnetic field in each of the 1 st stator magnetic pole 41 and the 2 nd stator magnetic pole 43.

At this time, the 1 st uneven portion 32 of the rotating rotor 2 formed at the shaft multiple angle "5X" of the upper edge portion passes through the 1 st stator magnetic pole 41 of the 1 st stator 40, and the 2 nd uneven portion 33 formed at the shaft multiple angle "6X" of the lower edge portion passes through the 2 nd stator magnetic pole 43. At this time, the magnetic flux generated by each 1 st stator pole 41 of the 1 st stator 40 is influenced by the 1 st uneven portion 32 facing each 1 st stator pole 41 of the 1 st stator 40 on the upper portion of the rotor 2, and the magnetic flux generated by each 2 nd stator pole 43 of the 2 nd stator 42 is influenced by the 2 nd uneven portion 33 facing each 2 nd stator pole 43 of the 2 nd stator 42 on the lower portion of the rotor 2.

Therefore, an angle signal indicating the detection angle θ 2 of the shaft multiple angle "5X" is output from the output winding of the 1 st stator magnetic pole 41 of the 1 st stator 40, and an angle signal indicating the detection angle θ 1 of the shaft multiple angle "6X" is output from the output winding of the 2 nd stator magnetic pole 43.

Fig. 14 to 17 show a rotation angle sensor according to embodiment 4. As shown in fig. 14, the rotation angle sensor includes: the stator includes a 1 st stator 53 formed by winding an excitation winding and an output winding around a plurality of 1 st stator poles 61 arranged in an annular shape, a 2 nd stator 54 formed by winding an excitation winding and an output winding around a plurality of 2 nd stator poles 66 arranged in an annular shape, a 3 rd stator 55 formed by winding an excitation winding and an output winding around a plurality of 3 rd stator poles 71 arranged in an annular shape, a 4 th stator 56 formed by winding an excitation winding and an output winding around a plurality of 4 th stator poles 76 arranged in an annular shape, and a rotor 52 arranged rotatably with a gap between the 1 st stator 53, the 2 nd stator 54, the 3 rd stator 55, and the 4 th stator 56 inside the 1 st stator 53 and the 2 nd stator 54 and outside the 3 rd stator 55 and outside the 4 th stator 56.

As shown in a of fig. 14, the 1 st stator 53 and the 2 nd stator 54 are disposed on the outer peripheral side of the rotor 52, and the 3 rd stator 55 and the 4 th stator 56 are disposed on the inner peripheral side of the rotor 52. The rotor body 57 is provided with a 1 st annular recess 101 and a 2 nd annular recess 111 on the outer peripheral surface and the inner peripheral surface thereof. A 1 st uneven portion 102 is provided at one edge portion of the 1 st annular recess 101, and a 2 nd uneven portion 103 is provided at the other edge portion.

Further, a 1 st uneven portion 112 is provided at one edge portion of the 2 nd annular concave portion 111, and a 2 nd uneven portion 113 is provided at the other edge portion. The 1 st concave-convex portion 102 of the 1 st annular concave portion 101 is formed at the same pitch as the 1 st concave-convex portion 112 of the 2 nd annular concave portion 111, and the 2 nd concave-convex portion 103 of the 1 st annular concave portion 101 is formed at the same pitch as the 2 nd concave-convex portion 113 of the 2 nd annular concave portion 111.

In the rotation angle sensor having such a configuration, the same angle detection signal can be output from the 1 st stator pole 61 of the 1 st stator 53 and the 3 rd stator pole 71 of the 3 rd stator 55, and the same angle detection signal can be output from the 2 nd stator pole 66 of the 2 nd stator 54 and the 4 th stator pole 76 of the 4 th stator 56.

Therefore, when the rotation angle sensor is actually used, only the 1 st stator 53 and the 2 nd stator 54, or the 3 rd stator 55 and the 4 th stator 56 are used. Thus, when one stator fails, the angle detection signal output from the stator pole of the other stator is used, thereby making it possible to provide the rotation angle sensor with a redundant function.

As shown in B of fig. 14, the rotor 52 has a 1 st annular recess 101 formed continuously in the circumferential direction to a uniform depth on the outer circumferential surface of the rotor main body 57 formed by cylindrically molding a magnetic steel material. Further, a 2 nd annular recess 111 of a uniform depth is continuously formed in the circumferential direction on the inner circumferential surface thereof. The depth of the 1 st annular recess 101 and the depth of the 2 nd annular recess 111 are, for example, about 0.5 mm.

As shown in B of fig. 14, the 1 st concave-convex portion 102 is provided at a fixed pitch at one arc-shaped edge portion of the 1 st annular concave portion 101 provided on the outer peripheral surface of the rotor main body 57, and the 2 nd concave-convex portion 103 is provided at a fixed pitch at the other arc-shaped edge portion. Similarly, the 1 st concave-convex portion 112 is provided at a fixed pitch at one arc-shaped edge portion of the 2 nd annular concave portion 111 provided on the inner peripheral surface of the rotor main body 57, and the 2 nd concave-convex portion 113 is provided at a fixed pitch at the other arc-shaped edge portion. The pitch of the 1 st concave-convex portion 102 of the 1 st annular concave portion 101 is the same as the pitch of the 1 st concave-convex portion 112 of the 2 nd annular concave portion 111, and the pitch of the 2 nd concave-convex portion 103 of the 1 st annular concave portion 101 is the same as the pitch of the 2 nd concave-convex portion 113 of the 2 nd annular concave portion 111.

The magnetic steel material of the rotor 52 including the rotor body 57 is a non-oriented electrical steel sheet, a grain-oriented electrical steel sheet, an iron alloy such as Fe — Al alloy and Fe — Co alloy, or the like, which is a high magnetic permeability material that generates a magnetic flux or a magnetic flux density necessary for detecting the rotation angle of the rotor 52 when a magnetic field is applied.

As shown in B of fig. 14, a sinusoidal wave portion, for example, is formed as a 1 st concave-convex portion 102 on the upper portion of the 1 st annular concave portion 101, and 5 rotor magnetic poles are formed in a convex shape so as to form a rotor having an axis double angle "5X" on the upper portion. In addition, a sinusoidal wave portion is formed as a 2 nd concave-convex portion 103 at the lower portion of the 1 st annular concave portion 101, and 6 rotor magnetic poles are formed in a convex shape so as to form a rotor having an axis double angle "6X" at the lower portion.

Similarly, a sinusoidal wave portion, for example, is formed as the 1 st concave-convex portion 112 on the upper portion of the 2 nd annular concave portion 111, and 5 rotor magnetic poles are formed in a convex shape so as to form a rotor having an axial double angle "5X" on the upper portion. In addition, a sinusoidal wave-shaped portion is formed as a 2 nd concave-convex portion 113 at the lower portion of the 2 nd annular concave portion 111, and 6 rotor magnetic poles are formed in a convex shape so as to form a rotor having an axis double angle "6X" at the lower portion.

The shape of the 1 st concave-convex portion 102, 112 and the shape of the 2 nd concave-convex portion 103, 113 may be substantially a sine wave shape, a rectangular pulse shape, a sawtooth pulse shape, or an arc-shaped waveform, in addition to a sine wave (cosine wave) shape which is accurate in physical properties.

The rotor 52 having the 1 st annular recess 101 and the 2 nd annular recess 111 provided in the rotor body 57 is formed in a part of the rotating shaft 69 or fixed to the outer peripheral portion of the rotating shaft 69. The 1 st annular recess 101 and the 2 nd annular recess 111 can be formed on the outer circumferential surface or the inner circumferential surface of the rotor main body 57 by cutting, etching, forging, casting, or the like.

In the case where a rotation angle sensor having a redundant function is not provided, a rotor body 58 having an annular recessed portion 81 formed only on the outer peripheral surface of the rotor body 58 as shown in a of fig. 15 may be used instead of the rotor body 57. In this case, as described above, the 1 st uneven portion 82 is provided at a constant pitch at one arc-shaped edge portion of the annular concave portion 81, and the 2 nd uneven portion 83 is provided at a constant pitch at the other arc-shaped edge portion. Similarly, as shown in B of fig. 15, a rotor body 59 in which an annular recess 84 is formed only on the inner peripheral surface of the rotor body 59 may be used. In this case, as described above, the 1 st concave-convex portions 85 are provided at a fixed pitch at one arc-shaped edge portion, and the 2 nd concave-convex portions 86 are provided at a fixed pitch at the other arc-shaped edge portion.

As shown in fig. 15C, a rotor body 60 having an annular protrusion 87 formed on the outer peripheral surface of the rotor body 60 may be used instead of the rotor body 57. In this case, the annular projection 87 is continuously formed as a projection having a thickness of about 0.5mm, for example, and having a constant thickness in the outer circumferential direction of the rotor body 60. Similarly to the above, the 1 st concave-convex portion 88 is provided at a fixed pitch at one arc-shaped edge portion of the annular convex portion 87, and the 2 nd concave-convex portion 89 is provided at a fixed pitch at the other arc-shaped edge portion. The annular projection may be formed on the inner circumferential surface of the rotor body in the same manner as in B of fig. 15.

As shown in a of fig. 14, the stator 51 is configured by disposing annular 1 st and 2 nd stators 53 and 54 on the outer peripheral side of the rotor 52 and disposing 3 rd and 4 th stators 55 and 56 on the inner peripheral side of the rotor 52. The 1 st stator 53 and the 2 nd stator 54, and the 3 rd stator 55 and the 4 th stator 56 are respectively disposed in parallel at a minute interval along the axial direction of the rotating shaft 69, and are fixed to the fixing portion 51 a.

The 1 st stator magnetic pole 61 of the 1 st stator 53 and the 2 nd stator magnetic pole 66 of the 2 nd stator 54 are each constituted by, for example, 14 poles, and the 1 st stator magnetic pole 61 and the 2 nd stator magnetic pole 66 constituted by 14 poles are each disposed with each magnetic pole facing inward at equal intervals in the circumferential direction, and are disposed so as to face the 1 st annular recess 101 of the rotor main body 57 with a slight gap. The structure of the 3 rd stator magnetic pole 71 of the 3 rd stator 55 and the structure of the 4 th stator magnetic pole 76 of the 4 th stator 56 are also the same as described above.

As shown in a of fig. 14, the 1 st stator magnetic pole 61 is formed by providing a stator core 62 of each magnetic pole protruding from the inside of an annular stator yoke and winding a stator winding 63 around each of the convex stator cores 62 of each magnetic pole. Similarly, the 2 nd stator pole 66 is configured by providing a stator core 67 of each pole protruding from the inside of an annular stator yoke and winding a stator winding 68 around the convex stator core 67 of each pole.

The stator windings 63 and 68 of the respective magnetic poles are each composed of an output winding for detection composed of an SIN winding and a COS winding which are shifted from each other in phase, and an excitation winding for excitation, and the terminals of the stator windings 63 of the respective magnetic poles of the 1 st stator magnetic pole 61 are drawn from the connection portions, respectively. The excitation windings of the stator windings 63 and 68 are connected to an excitation power supply circuit that supplies, for example, an ac current of about 10 kHz. The SIN and COS windings of the output windings of the stator windings 63 and 68 output the SIN and COS output signals as the rotor 52 rotates, and the output terminals are connected to the input side of the R/D converter.

Similarly, the 3 rd stator magnetic pole 71 of the 3 rd stator 55 and the 4 th stator magnetic pole 76 of the 4 th stator 56 are respectively formed of, for example, 14 poles, and the 3 rd stator magnetic pole 71 and the 4 th stator magnetic pole 76 formed of 14 poles are respectively arranged with the respective magnetic poles facing outward at equal intervals. The 3 rd stator magnetic pole 71 of the 3 rd stator 55 and the 4 th stator magnetic pole 76 of the 4 th stator 56 disposed inside the rotor main body 57 are used as a backup in the event of a failure, for example.

As shown in a of fig. 14, the 3 rd stator pole 71 is configured by providing a stator core 72 of each pole protruding from the inside of an annular stator yoke and winding a stator winding 73 around each of the convex stator cores 72 of each pole. Similarly, the 4 th stator pole 76 is formed by projecting a stator core 77 of each pole inside an annular stator yoke and winding a stator winding 78 around the convex stator core 77 of each pole.

The stator windings 73 and 78 of the respective magnetic poles are each composed of an output winding for detection composed of an SIN winding and a COS winding which are shifted from each other in phase, and an excitation winding for excitation, and the terminals of the stator windings 73 of the respective magnetic poles of the 3 rd stator magnetic pole 71 are respectively led out from the connection portions. The excitation windings of the stator windings 73 and 78 are connected to an excitation power supply circuit that supplies, for example, an ac current of about 10 kHz. The SIN and COS windings of the output windings of the stator windings 73 and 78 output the SIN and COS output signals as the rotor 52 rotates, and the output terminals are connected to the input side of the R/D converter.

As shown in fig. 14 a and 14B, the stator core 62 of the 1 st stator magnetic pole 61 of the 1 st stator 53 is disposed at a position where an inner end portion thereof faces the 1 st concave-convex portion 102 of the rotor 52, and the stator core 77 of the 2 nd stator magnetic pole 66 of the 2 nd stator 54 is disposed at a position where an inner end portion thereof faces the 2 nd concave-convex portion 103 of the rotor 52.

Accordingly, when the rotor 52 rotates, the 1 st concave-convex portion 102 and the 2 nd concave-convex portion 103 move in the circumferential direction, and the overlapping area where the stator core 62 of the 1 st stator magnetic pole 61 of the 1 st stator 53 overlaps with the 1 st concave-convex portion 102 with a gap therebetween changes similarly to the conventional change in gap permeability. Similarly, the overlapping area where the stator core 67 of the 2 nd stator pole 66 of the 2 nd stator 54 overlaps the 2 nd concave-convex portion 103 with a gap therebetween changes similarly to the change in the conventional gap permeability.

With this configuration, a common rotor can be configured by only the single rotor 52, and a rotation angle sensor capable of outputting detection signals of different shaft multiple angles of the shaft multiple angle "5X" and the shaft multiple angle "6X" can be provided.

As described above, the 3 rd stator 55 and the 4 th stator 56 are configured similarly to the 1 st stator 53 and the 2 nd stator 54, and the stator core 72 of the 3 rd stator magnetic pole 71 of the 3 rd stator 55 is disposed at a position where the outer end portion thereof faces the 1 st concave-convex portion 112 of the 2 nd annular recess 111 of the rotor 52. The stator core 77 of the 4 th stator pole 76 of the 4 th stator 56 is disposed at a position where its outer end portion faces the 2 nd concave-convex portion 113 of the rotor 52, and the 3 rd stator 55 and the 4 th stator 56 are provided as a preliminary to failure or the like. Thus, even when the rotor 52 has a redundant function, the occupied space of the rotor 52 is extremely smaller than that of the conventional rotor, and the entire rotation angle sensor can be downsized.

Next, the operation of the rotation angle sensor configured as described above is described, and when the rotation shaft 69 and the rotor 52 rotate, an ac excitation current is supplied to the 1 st stator magnetic pole 61 of the 1 st stator 53 and the 2 nd stator magnetic pole 66 of the 2 nd stator 54, and an ac magnetic field is generated in each of the 1 st stator magnetic pole 61 and the 2 nd stator magnetic pole 66.

At this time, the 1 st uneven portion 102 of the shaft multiple angle "5X" formed at the upper edge portion of the 1 st annular recess 101 of the rotor main body 57 passes through each 1 st stator magnetic pole 61 of the 1 st stator 53, and the 2 nd uneven portion 103 of the shaft multiple angle "6X" formed at the lower edge portion passes through the 2 nd stator magnetic pole 66. At this time, the magnetic flux generated by each 1 st stator magnetic pole 61 of the 1 st stator 53 is influenced by the 1 st uneven portion 102 facing each 1 st stator magnetic pole 61 of the 1 st stator 53 in the upper portion of the 1 st annular concave portion 101 of the rotor main body 57, and the magnetic flux generated by each 2 nd stator magnetic pole 66 of the 2 nd stator 54 is influenced by the 2 nd uneven portion 103 facing each 2 nd stator magnetic pole 66 of the 2 nd stator 54 in the lower portion of the 1 st annular concave portion 101.

Therefore, as the rotor 52 rotates, an angle signal indicating the detection angle θ 2 of the shaft multiple angle "5X" is output from the output winding of the 1 st stator magnetic pole 61 of the 1 st stator 53, that is, the SIN winding and the COS winding thereof, and an output voltage signal indicating the detection angle θ 1 of the shaft multiple angle "6X" is output from the SIN winding and the COS winding of the 2 nd stator magnetic pole 66. As shown in fig. 16, the output voltage signal output at this time is the SIN output voltage signal and the COS output voltage signal corresponding to the mechanical angle of the rotor 52, and is output as effective detection signals.

The angle signals indicating the detected angles θ 1 and θ 2 are transmitted to the R/D converter, which converts the angle signals into triangular wave signals, samples the triangular wave signals, converts the triangular wave signals into digital signals, and outputs the digital signals to the signal processing circuit, as in embodiment 1. The signal processing circuit calculates the absolute angle of the rotor 52 in accordance with the detected angles θ 1 and θ 2, as in embodiment 1.

Fig. 17 shows errors of the detected angle with respect to the rotation angle (mechanical angle) of the rotor 52 when the rotation angle sensor according to embodiment 4 is manufactured in a trial and tested for performance. As shown in fig. 17, the detected angle error periodically changes in accordance with the mechanical angle of the rotor, but the error range is within a range that does not cause any problem in actual use.

Description of the reference numerals

1. A stator; 2. a rotor; 3. a 1 st stator; 4. a 2 nd stator; 9. a rotating shaft; 11. 1 st stator magnetic pole; 12. a stator core; 13. winding a stator; 16. 2 nd stator magnetic pole; 17. a stator core; 18. winding a stator; 20. a signal processing circuit; 21. an R/D converter; 23. a CPU; 24. an input-output circuit; 25. a memory; 31. a band-shaped body; 31a, an outer peripheral surface; 31b, an inner peripheral surface; 32. 1 st concavo-convex part; 33. a 2 nd concave-convex part; 34. a synthetic resin-made circular ring portion; 35. a synthetic resin-made circular ring portion; 36. a synthetic resin-made circular ring portion; 37. a bearing; 38. a housing; 40. a 1 st stator; 41. 1 st stator magnetic pole; 42. a 2 nd stator; 43. and 2 nd stator magnetic pole.