阅读说明：本技术 旋转致动器及其制造方法 (Rotary actuator and method of manufacturing the same ) 是由 加藤祐里子 粂干根 角弘之 于 2020-04-14 设计创作，主要内容包括：旋转致动器用于车辆的线控换挡系统(11)中。致动器包括马达(30)、控制器(16)、外壳(19)和端子(92)。控制器(16)控制马达。外壳(19)保持马达(30)的定子(31)和控制器(16)。端子(92)将定子(31)的线圈(38)电连接至控制器(16)。端子(92)包括电连接到线圈(38)的熔接部(94)。熔接部(94)在与马达(30)的轴向平行的方向上被压缩。(The rotary actuator is used in a shift-by-wire system (11) of a vehicle. The actuator includes a motor (30), a controller (16), a housing (19), and a terminal (92). A controller (16) controls the motor. The housing (19) holds a stator (31) of the motor (30) and the controller (16). The terminals (92) electrically connect the coils (38) of the stator (31) to the controller (16). The terminal (92) includes a fusion splice (94) that is electrically connected to the coil (38). The welded portion (94) is compressed in a direction parallel to the axial direction of the motor (30).)

1. A rotary actuator for use in a shift-by-wire system (11) for a vehicle, the rotary actuator comprising:

a motor (30);

a controller (16) that controls the motor;

a housing (19) holding a stator (31) of the motor and the controller; and

terminals (92, 102, 112, 122) electrically connecting coils (38) of the stator to the controller, wherein,

the terminal includes a weld (94, 104, 124) electrically connected to the coil, and

the weld is compressed in a direction parallel to an axial direction of the motor.

2. The rotary actuator of claim 1,

the stator comprises a portion (109) having a maximum thickness in the axial direction, and

the weld is disposed radially inward or outward of the portion of the stator.

3. The rotary actuator of claim 2,

the terminals (92, 102, 122) are integrally formed with a holding member (93) that is a separate member from the housing.

4. The rotary actuator of claim 1 or 2,

the terminal (112) is integrally formed with the housing.

5. A method of manufacturing a rotary actuator (10) for use in a shift-by-wire system (11) for a vehicle, the rotary actuator comprising: a motor (30); a controller (16) that controls the motor; a housing (19) housing the stator (31) of the motor and the controller; and electrically connecting the coils (38) of the stator to terminals (92, 102, 112, 122) of the controller, the method comprising:

electrically connecting the weld (94, 104, 102) to the coil by compressing the weld in a compression direction while heating the weld of the terminal; and

bending the terminal together with the welding portion so that the compression direction of the welding portion is converted to be parallel to the axial direction of the motor.

Technical Field

The present invention relates to a rotary actuator and a method of manufacturing the rotary actuator.

Background

Conventionally, there is known an mechatronic rotary actuator in which an operation unit having a motor and a controller for controlling the motor are integrally formed. In patent document 1(JP2009-141992a1), the coils of the motor stator are electrically connected with the controller via terminals attached to the bobbin. The ends of the coil are electrically connected to the terminals by welding (soldering).

Disclosure of Invention

In patent document 1, the terminals are pressed in the radial direction of the motor to weld the terminals. Therefore, the total thickness in the axial direction of the welded portions of the stator and the terminals increases, and therefore the size of the rotary actuator in the axial direction increases.

The present invention has been provided in view of the above circumstances, and an object of the present invention is to provide a rotary actuator with a reduced thickness.

One aspect of the present invention is a rotary actuator for use in a shift-by-wire system of a vehicle. The actuator includes a motor, a controller that controls the motor, a housing that holds a stator of the motor and the controller, and a terminal that electrically connects a coil of the stator to the controller. The terminal includes a weld electrically connected to the coil. The weld is compressed in a direction parallel to the axial direction of the motor.

By making the compression direction of the welded portion parallel to the axial direction of the motor, the total thickness in the axial direction of the stator and the terminal welded portion can be made smaller by the amount of compression of the welded portion by welding in the axial direction. Therefore, by providing a member adjacent to the weld at a position close to the motor, the size of the rotary actuator in the axial direction can be reduced.

Drawings

Fig. 1 is a schematic view showing a shift-by-wire system to which a rotary actuator according to a first embodiment is applied.

Fig. 2 is a diagram showing the shift-position switching mechanism of fig. 1.

Fig. 3 is a sectional view of the rotary actuator according to the first embodiment.

Fig. 4 is an enlarged view of the portion IV of fig. 3.

Fig. 5 is a view of the stator and the bus bar of fig. 3 viewed in the V direction.

Fig. 6 is a sectional view of the stator and the bus bar taken along line VI-VI of fig. 5.

Fig. 7 is a view illustrating the bus bar of fig. 5.

Fig. 8 is a diagram illustrating a welding step of connecting the terminal and the coil of fig. 3.

Fig. 9 is a sectional view of a stator and a bus bar of a rotary actuator according to a second embodiment corresponding to fig. 6 of the first embodiment.

Fig. 10 is a front view showing an upper housing and a terminal of the rotary actuator according to the third embodiment.

Fig. 11A is a diagram showing a state before the welding step of the rotary actuator according to the fourth embodiment, in which the welded portion is viewed in the axial direction.

Fig. 11B is a diagram showing a state before the welding step of the rotary actuator according to the fourth embodiment, in which the welded portion is viewed in the radial direction.

Fig. 12A is a diagram showing a welding step of the rotary actuator according to the fourth embodiment, in which a welded portion is viewed in the axial direction.

Fig. 12B is a diagram showing a welding step of the rotary actuator according to the fourth embodiment, in which the welded portion is viewed in the radial direction.

Fig. 13A is a diagram showing a bending step of the rotary actuator according to the fourth embodiment, in which the welded portion is viewed in the axial direction.

Fig. 13B is a diagram showing a bending step of the rotary actuator according to the fourth embodiment, in which the welded portion is viewed in the radial direction.

Fig. 14A is a diagram showing a bending step of the rotary actuator according to the fourth embodiment, in which the weld is viewed in the axial direction.

Fig. 14B is a diagram showing a bending step of the rotary actuator according to the fourth embodiment, in which the welded portion is viewed in the radial direction.

Fig. 15 is a front view of a motor and a bus bar of the rotary actuator according to the comparative example corresponding to the view of fig. 5.

Fig. 16 is a cross-sectional view of the stator and bus bar taken along line XVI-XVI in fig. 15, corresponding to the view of fig. 6.

Fig. 17 is a diagram comparing thicknesses of the stator and the bus bar between the first embodiment and the comparative example.

Detailed Description

Hereinafter, a plurality of embodiments of a rotary actuator (hereinafter, referred to as an "actuator") will be described with reference to the drawings. In these embodiments, substantially the same components are denoted by the same reference numerals, and the description thereof is omitted.

[ first embodiment ]

In this embodiment, the actuator is used as a driver of a shift-by-wire system for a vehicle.

(Shift-by-wire System)

The structure of the shift-by-wire system will be described with reference to fig. 1 and 2. As shown in fig. 1, the shift-by-wire system 11 includes a shift operation device 13 and an actuator 10, the shift operation device 13 outputting a command (i.e., a command signal) to specify a shift range for the transmission 12, and the actuator 10 operating a shift-range switching mechanism 14 of the transmission 12. The actuator 10 includes: an operating unit 15 having a motor 30, and a controller 16, the controller 16 controlling the motor 30 in response to a shift range command signal.

As shown in fig. 2, the shift position switching mechanism 14 includes a shift position switching valve 20, a brake spring 21 and a brake lever 22, a parking lever 24 and a manual shaft 26. The shift range switching valve 20 controls the supply of hydraulic pressure to a hydraulic operating mechanism in the transmission 12 (see fig. 1). The brake spring 21 and the brake lever 22 are configured for holding a shift gear. The parking lever 25 is configured to prevent the output shaft of the transmission 12 from rotating by fitting the parking lever 24 into the parking gear 23 of the output shaft when the shift range is switched to the parking range. The manual shaft 26 rotates together with the brake lever 22.

The shift-gear switching mechanism 14 rotates the brake lever 22 together with the manual shaft 26 to move the valve body 27 and the parking lever 25 of the gear switching valve 20 connected with the brake lever 22 to a position corresponding to the target shift gear. In the shift-by-wire system 11, the actuator 10 is connected to the manual shaft 26 to electrically perform a shift range change.

(actuator)

Next, the structure of the actuator 10 will be described. As shown in fig. 3, the actuator 10 is an mechatronic actuator having an operation unit 15 and a controller 16 in a housing 19.

The housing 19 includes a plate cover 67 and a case 60, and the case 60 includes a cylindrical upper case 61 and a cup-shaped lower case 62. A spacer 65 is formed between the one end 63 and the other end 64 of the upper case 61. The control plate 71 is disposed inside the one end 63. The control board 71 is covered with a board cover 67 provided at the opening of the one end 63, thereby ensuring shielding of the control board 71. The lower housing portion 62 is attached to another end 64. The lower case portion 62 has a cylindrical projecting portion 69 projecting toward the side opposite to the upper case 61. The manual shaft 26 is inserted into the cylindrical protrusion 69.

The operation unit 15 includes a motor 30 as a driving force generator, an output shaft 40 disposed in parallel with the motor 30, and a reduction mechanism 50, the reduction mechanism 50 reducing the rotation speed of the motor 30 and transmitting the rotation to the output shaft 40.

The motor 30 includes: a stator 31 press-fitted and fixed to a plate shell 68 at the other end 64; a rotor 32 disposed inside the stator 31; and a motor shaft 33 that rotates together with the rotor 32 about the rotation axis AX 1. The motor shaft 33 is rotatably supported by both the bearing 34 provided inside the plate case 68 and the bearing 35 provided in the lower housing portion 62. Further, the motor shaft 33 has an eccentric portion 36 eccentric to the rotation axis AX1 at a position on the side of the rotor 32 close to the lower housing portion 62. The motor 30 can be rotated bidirectionally by controlling the current supplied to the coil 38 by the controller 16, and can also be stopped at a desired rotational position. The plug 39 is attached to the through hole of the plate cover 67. In the event of a malfunction, the motor shaft 33 may be forcibly rotated manually after removing the plug 39.

The speed reduction mechanism 50 includes: a first speed reduction portion 17 including a ring gear 51 and a sun gear 52; and a second reduction part 18 including a drive gear 53 and a driven gear 54 as parallel shaft type gears. The ring gear 51 is disposed coaxially with the rotation axis AX 1. The sun gear 52 is rotatably supported about an eccentric axis AX2 by a bearing 55 fitted in the eccentric portion 36. The sun gear 52 meshes with the ring gear 51 and is tightly fitted inside the ring gear 51. When the motor shaft 33 rotates, the sun gear 52 performs a planetary motion in which the sun gear 52 revolves around the rotation axis AX1 and rotates around the eccentric axis AX 2. At this time, the rotation speed of the sun gear 52 is reduced with respect to the rotation speed of the motor shaft 33. The sun gear 52 has a bore 56 for transmitting rotational motion.

The drive gear 53 is provided on the rotation axis AX1, and is rotatably supported about the rotation axis AX1 by a bearing 57 fitted on the motor shaft 33. Furthermore, the drive gear 53 has a projection 58 for transmitting a rotational movement, which is inserted into the hole 56. The rotational movement of the sun gear 52 is transmitted to the drive gear 53 through the engagement between the holes 56 and the projections 58. The hole 56 and the projection 58 constitute a transmission 59. The driven gear 54 is provided on a rotation axis AX3 parallel to the rotation axis AX1 and coaxial with the cylindrical protrusion 69. The driven gear 54 meshes with the drive gear 53 to externally drive the gear 53. When the drive gear 53 rotates about the rotation axis AX1, the driven gear 54 rotates about the rotation axis AX 3. At this time, the rotation speed of the driven gear 54 is reduced relative to the rotation speed of the drive gear 53.

The output shaft 40 has a cylindrical shape, and is disposed coaxially with the rotation axis AX 3. The spacer 65 has a support through hole 66 coaxial with the rotation axis AX 3. The output shaft 40 is rotatably supported about the rotation axis AX3 by the first flange bushing 46 fitted in the support through hole 66 and the second flange bushing 47 fitted inside the cylindrical protrusion 69. The driven gear 54 is a separate component from the output shaft 40, is fitted to the outside of the output shaft 40, and is connected with the output shaft 40 to transmit rotational motion. The manual shaft 26 is inserted into the output shaft 40, and is connected to the output shaft 40 by, for example, spline fitting to transmit rotational motion.

One end 41 of the output shaft 40 is rotatably supported by a first flange bushing 46. The other end 42 of the output shaft 40 is rotatably supported by a second flange bushing 47. The driven gear 54 is supported in the axial direction by being clamped between the first flange portion 48 of the first flange bushing 46 and the second flange portion 49 of the second flange bushing 47. In another embodiment, the driven gear 54 may be supported in the axial direction by being clamped between a pair of support portions such as the housing 60 and another plate.

The controller 16 includes a plurality of electronic components for controlling the motor 30, a control board 71 on which the electronic components are implemented, an output shaft position detection sensor 72 implemented on the control board 71, and a motor position detection sensor 73 implemented on the control board 71. The control plate 71 has a plurality of outer peripheral fixing portions 75 fixed to the spacer 65 by heat caulking at the outer peripheral surface of the control plate 71.

The plurality of electronic components include a microcomputer 81, a MOSFET 82, a capacitor 83, a diode 84, an ASIC 85, an inductor 86, a resistor 87, a capacitor chip 88, and the like.

An output shaft position detection sensor 72 is provided on the control plate 71 at a position facing the magnet 43. The magnet 43 is fixed to a holder 44 attached to the output shaft 40. The output shaft position detection sensor 72 detects the rotational positions of the output shaft 40 and the manual shaft 26 that rotates together with the output shaft 40 by detecting the magnetic flux generated by the magnet 43.

The motor position detection sensor 73 is provided on the control board 71 at a position facing the magnet 45. The magnet 45 is fixed to the holder 37 attached to the motor shaft 33. The motor position detection sensor 73 detects the rotational position of the motor shaft 33 and the rotor 32 by detecting the magnetic flux generated by the magnet 45.

(connection structure)

Next, the structure of the connection portion between the motor 30 and the controller 16 will be described. Hereinafter, the radial direction of the motor 30 is simply referred to as "radial direction", the axial direction of the motor 30 is simply referred to as "axial direction", and the circumferential direction of the motor 30 is simply referred to as "circumferential direction".

As shown in fig. 3 to 7, the actuator 10 includes a bus bar 91. The bus bar 91 includes a plurality of terminals 92 that electrically connect the coil 38 to the control board 71. The bus bar 91 further includes a resin holding member 93 that molds a part of each terminal 92.

The holding member 93 is a member separate from the housing 19, is formed in a ring shape, and is arranged coaxially with the stator 31. The holding member 93 is fixed to a portion of the spacer 65 of the upper case portion 61 facing the control plate 71, for example, by hot forging.

The terminals 92 are arranged along the circumferential direction of the bus bar 91. Each terminal 92 includes a fusion portion 94, a leg portion 95, and an intermediate portion 96. The welded portion 94 is located radially inward of the holding member 93. The lead portion 95 is located radially outward of the holding member 93. The intermediate portion 96 connects the fusion portion 94 with the leg portion 95. The lead portion 95 protrudes toward the control plate 71 in the axial direction, and is electrically connected to the control plate 71 by, for example, brazing or snap-fitting. The holding member 93 forms a part of the intermediate portion 96.

As shown in fig. 8, the weld 94 is formed in a C-shape to sandwich an end portion 97 (hereinafter referred to as "coil end") of the coil 38 in the axial direction. The coil end 97 is compression-joined (welded) to the welded portion 94 by welding (welding). The compression direction of the weld 94 is parallel to the axial direction. It should be noted that during the welding step of the manufacturing process, the welded portion 94 is radially compressed while being heated by the welding terminal 98, as shown in fig. 12A and 12B, and the welded portion 94 and the coil end 97 are electrically connected via welding (soldering).

As described above, in the first embodiment, the terminal 92 has the fusion-spliced portion 94 electrically connected to the coil 38. The compression direction of the weld 94 is aligned with the axial direction of the motor 30. In this way, by setting the compression direction of the weld 94 to be parallel to (or aligned with) the axial direction of the motor 30, the total thickness H1 (see fig. 6) of the stator 31 and the weld 94 in the axial direction can be reduced by the amount of compression of the weld 94 in the axial direction by welding. Therefore, by disposing the control plate 71 adjacent to the weld 94, for example, at a position close to the motor 30, the actuator 10 can be reduced in size in the axial direction.

Here, the advantages of the first embodiment will be described by comparison with comparative examples shown in fig. 15 and 16. In the comparative example, the compression direction of the fusion-spliced portion 204 of each terminal 202 is perpendicular to the motor axial direction. In this comparative example, each fusion-joined portion 204 is not deformed in the axial direction by fusion, and therefore the total thickness H2 (see fig. 16) in the axial direction of the stator 31 and the fusion-joined portion 204 is not reduced. In contrast, in the first embodiment shown in fig. 17, the thickness H1 of the motor 30 is smaller than that of the comparative example by the compression amount H by which the welded portion 94 is deformed (compressed) in the axial direction by welding.

In the first embodiment, the terminal 92 is integrally molded with the holding member 93 (which is a member separate from the housing 19). As a result, the plurality of terminals 92 are put together, so that the terminals are easily assembled (handled), and the axial dimension of the motor 30 can be reduced by integrating with the bus bar 91 as a single member.

[ second embodiment ]

In the second embodiment, the stator 31 includes a portion having the maximum thickness in the axial direction (hereinafter referred to as a maximum thickness portion), and the welded portion 104 of the terminal 102 of the bus bar 101 is located radially inward of the maximum thickness portion of the stator 31, as shown in fig. 9. In the present embodiment, the maximum thickness portion is a protrusion 109 of the bobbin 108 that holds the coil 38 at a position radially outside the coil 38. The protrusion 109 protrudes in the axial direction from one surface of the stator 31. The weld 104 is disposed on the one surface. The weld 104 is configured not to protrude beyond the protrusion 109 in the axial direction. Therefore, the axial thickness H1 between the other surface of the stator 31 (which is opposite to the above-described one surface) and the weld 104 may be equal to or less than the axial thickness H3 of the maximum thickness portion 109. Therefore, by arranging the control board adjacent to the weld 104, for example, at a position close to the motor, the actuator 10 can be reduced in size in the axial direction.

Specifically, in the second embodiment, the fusion-spliced portion 104 is provided so as not to protrude beyond the maximum thickness portion 109 in the axial direction. Therefore, even if the weld portion 104 is provided on one surface of the stator 31 and thus completely overlaps the stator 31 in the axial direction, the thickness H1 may be smaller than the thickness H3 of the maximum thickness portion 109.

[ third embodiment ]

In the third embodiment, as shown in fig. 10, the terminal 112 is integrally formed with the housing 19. Specifically, the terminal 112 is insert-molded with the spacer 65 of the upper case 61. As a result, the plurality of terminals 112 are arranged together, so that the terminals are easily assembled (handled), and by integrating the motor 30 as a single component like the housing 19, the axial dimension of the motor 30 can be reduced.

[ fourth embodiment ]

In the fourth embodiment, a method for manufacturing the actuator 10 will be described with reference to fig. 11A to 14B. The method includes a welding step and a bending step. Before the welding step, the welded portion 124 of the terminal 122 is formed so that the insertion direction of the coil end 97 is parallel to the axial direction, as shown in fig. 11A and 11B. In other words, the insertion hole for the fusion-spliced portion 124 of the coil end 97 is opened in the direction parallel to the axial direction.

In the welding step, welding (soldering) is performed to electrically connect the welded portion 124 to the coil end 97 by compressing and heating the welded portion 124 of the terminal 122 in a direction perpendicular to (i.e., intersecting) the axial direction, as shown in fig. 12A and 12B.

Then, in the bending step, the terminal 122 is bent together with the fusion-spliced portion 124 at a specific portion of the terminal 122 (i.e., a connection portion between the fusion-spliced portion 124 and the intermediate portion 96) as shown in fig. 13A and 13B, so that the compression direction of the fusion-spliced portion 124 is switched (rotated) to be parallel to the axial direction as shown in fig. 14A and 14B.

As described above, the manufacturing process of the actuator 10 can be easily performed by bending the fusion-bonded portion 94 after compression-bonding the fusion-bonded portion 124 to the coil end 97 in the direction perpendicular to the axial direction.

[ other examples ]

In another embodiment, the weld may be located radially outward of the portion of the stator having the greatest thickness. In another embodiment, the bus bar is not limited to one holding member, and may have a plurality of holding members. In yet another embodiment, the control board may be fixed not only by heat staking, but also by other fixing means such as screw fastening, gluing, press fitting, and press fixing. Further, the control board is not necessarily limited to being fixed to the case, and may be fixed to a board cover that is another part of the housing.

The present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the gist of the present invention.