JP2016129488A - Rotation transmission device and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation transmission device capable of positioning a sensor magnet in a direction of rotation in a configuration in which a sensor magnet composed of an anisotropic pole magnet is insert-molded.SOLUTION: A sensor magnet 36 composed of an anisotropic pole magnet for detecting a rotation state of a drive side rotator 32 that is integrally rotated with a rotation shaft (a drive shaft) is integrally formed with the drive side rotator 32 (a resin molding part 40) by insert-molding. The sensor magnet 36 is formed with a notch 36b (a positioning recess) for positioning the sensor magnet 36 in a direction of rotation.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a rotation transmission device and a motor.

  Conventionally, for example, the motor of Patent Document 1 includes a sensor magnet that rotates integrally with a rotating shaft (drive shaft) of a motor unit, and a magnetic detection element (such as a Hall element or a magnetoresistive element) disposed in the vicinity of the sensor magnet. I have. The sensor magnet is configured such that the N pole and the S pole appear alternately in the rotation direction (circumferential direction) on the outer peripheral surface thereof. The magnetic detection element detects a change in the magnetic field accompanying the rotation of the sensor magnet, and detects a rotation state such as a rotation speed and a rotation speed of the rotation shaft. Further, in the motor of Patent Document 1, the rotation shaft of the motor unit and the worm shaft of the speed reduction mechanism are connected via a rotation transmission device, and the rotation transmission device is a resin drive side rotation connected to the rotation shaft. Have a body. And the above-mentioned sensor magnet is embed | buried by insert molding inside the drive side rotary body. Thereby, even if a cover etc. are not provided separately, the scattering of the fragment by the crack of a sensor magnet can be prevented.

JP-A-2005-160161

  An object of the present invention is to provide a rotation transmission device and a motor that can suppress a decrease in magnetic flux on the outer peripheral side of the sensor magnet and also suppress a decrease in a magnetic flux peak of the sensor magnet (a magnetic flux in the circumferential center of the magnetic pole). It is to provide.

  A rotation transmission device that solves the above problem includes a resin-made rotating body that is interposed between a driving shaft and a driven shaft and transmits the rotational force of the driving shaft to the driven shaft, and the rotating state of the rotating body A rotation transmission device in which a sensor magnet for detecting the rotation and the rotating body are integrally formed, and a positioning recess for positioning the sensor magnet in the rotation direction is formed on an inner peripheral surface of the sensor magnet. In addition, the rotating body is formed with a rotation preventing portion that enters the positioning recess, and the sensor magnet is magnetized with the positioning recess as a boundary portion of the magnetic pole of the sensor magnet.

  A motor that solves the above problems includes a motor unit having a drive shaft, a speed reduction mechanism having a driven shaft that rotates based on the rotation of the drive shaft, and the drive shaft interposed between the drive shaft and the driven shaft. A rotation transmission device that transmits the rotational force to the driven shaft, and the rotation transmission device described above is used as the rotation transmission device.

  Therefore, according to the above-described invention, it is possible to suppress a decrease in the magnetic flux on the outer peripheral side of the sensor magnet, and it is possible to suppress a decrease in the peak of the magnetic flux of the sensor magnet (a magnetic flux at the center in the circumferential direction of the magnetic pole).

Sectional drawing of the motor of embodiment. Sectional drawing which shows the motor of the same form partially. The disassembled perspective view of the clutch of the same form. (A) The front view of the drive side rotary body of the form, (b) AA sectional drawing of the figure (a). Sectional drawing of the drive side rotary body of the same form. The schematic diagram for demonstrating the manufacturing method of the motor of the form. The schematic diagram for demonstrating the manufacturing method of the motor of the form. Sectional drawing which shows the sensor magnet of another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
The motor of this embodiment shown in FIG. 1 is used as a drive source of a power window device, for example. The motor includes a motor unit 1, a speed reduction unit 2, and a clutch 3 (rotation transmission device).

[Motor part]
A pair of magnets 5 are fixed to an inner peripheral surface of a bottomed cylindrical yoke housing (hereinafter simply referred to as a yoke) 4 constituting the motor unit 1 so as to face each other. A child 6 is arranged. The armature 6 includes a rotation shaft 7 (drive shaft) disposed at the center of the yoke 4. A base end portion (upper end portion in FIG. 1) of the rotating shaft 7 is pivotally supported by a bearing 8 provided at the center of the bottom of the yoke 4, and a cylindrical portion is provided at a tip side of the rotating shaft 7. A commutator 9 is fixed. In addition, a connecting portion 7a having a two-sided width shape that is chamfered in parallel from a cylindrical shape is formed at the tip of the rotating shaft 7, and the tip of the connecting portion 7a has a curved surface shape (part of a spherical surface). Yes.

  A flange portion 4 a extending outward is formed at the opening of the yoke 4, and a brush holder 10 is fitted into the opening of the yoke 4. The brush holder 10 is formed by integrally forming a holder main body 10 a having a shape for closing the opening of the yoke 4 and a connector portion 10 b protruding outward in the radial direction of the yoke 4. The holder main body 10a holds a pair of brushes 11 that are connected to the connector portion 10b by wires (not shown) and that are in sliding contact with the commutator 9. A bearing 12 is provided at the center of the holder main body 10a, and the bearing 12 pivotally supports a portion of the rotating shaft 7 between the commutator 9 and the connecting portion 7a. When the external power supplied to the brush 11 via the connector portion 10b is supplied to the armature 6 via the commutator 9, the armature 6 (rotating shaft 7) is driven to rotate, that is, the motor portion. 1 is rotationally driven.

[Decelerator]
The speed reduction portion 2 is formed by housing a speed reduction mechanism 22 and the like in a resin gear housing 21. The gear housing 21 includes a fixing portion 21 a for fixing the gear housing 21 to the motor portion 1 at a portion (an upper end portion in FIG. 1) facing the motor portion 1 in the axial direction. The fixing portion 21 a has an outer shape similar to the outer shape of the flange portion 4 a of the yoke 4, and a fitting recess 21 b that opens to the inside of the yoke 4 is formed in the fixing portion 21 a. Then, in a state where the holder main body 10a of the brush holder 10 is fitted in the fitting recess 21b, the fixing portion 21a and the flange portion 4a in contact with the fixing portion 21a are fixed by the screw 23, The yoke 4 is fixed to the gear housing 21, and the motor unit 1 and the speed reduction unit 2 are integrated.

  In the gear housing 21, a clutch housing recess 21c is provided in the center of the bottom of the fitting recess 21b in the axial direction, and the worm shaft housing extends along the axial direction of the rotary shaft 7 from the center of the bottom of the clutch housing recess 21c. The portion 21d is recessed. Further, in the gear housing 21, a wheel accommodating portion 21e is recessed on the side (right side in FIG. 1) of the worm shaft accommodating portion 21d. The wheel housing portion 21e and the worm shaft housing portion 21d are connected at the central portion in the axial direction (longitudinal direction) of the worm shaft housing portion 21d.

  A substantially cylindrical worm shaft 24 is accommodated in the worm shaft accommodating portion 21d. The worm shaft 24 is made of a metal material, and a screw-like worm portion 24a is formed in the central portion in the axial direction. The worm shaft 24 is axially supported at both ends in the axial direction by a pair of metal and cylindrical bearings 25 and 26 arranged at both ends in the axial direction of the worm shaft accommodating portion 21d. The worm shaft 24 in the worm shaft housing portion 21d is supported by the bearings 25 and 26 so as to be arranged coaxially with the rotary shaft 7, that is, the central axis L1 of the rotary shaft 7 and the central axis of the worm shaft 24. It arrange | positions so that L2 may be on a straight line (refer FIG. 2).

  A disc-shaped worm wheel 27 that meshes with the worm portion 24a of the worm shaft 24 is rotatably accommodated in the wheel accommodating portion 21e. The worm wheel 27 constitutes the speed reduction mechanism 22 together with the worm shaft 24. In addition, an output shaft 28 that rotates integrally with the worm wheel 27 extends in the axial direction of the worm wheel 27 (in the direction perpendicular to the paper surface in FIG. 1). . A known window regulator (not shown) for raising and lowering the window glass of the vehicle is drivingly connected to the output shaft 28.

[Clutch (rotation transmission device)]
The clutch 3 for connecting the rotary shaft 7 and the worm shaft 24 is accommodated in the clutch accommodating recess 21c. As shown in FIGS. 2 and 3, the clutch 3 includes a clutch housing 31, a driving side rotating body 32, a support member 33, a rolling element 34, a driven side rotating body 35, and a sensor magnet 36.

  The clutch housing 31 has a cylindrical shape, and a hook-shaped fixed flange portion 31 a extending radially outward is formed at one end portion in the axial direction of the clutch housing 31. The outer diameter of the cylindrical portion of the clutch housing 31 is formed substantially equal to the inner diameter of the clutch housing recess 21c, and the outer diameter of the fixed flange portion 31a is formed larger than the inner diameter of the clutch housing recess 21c. As shown in FIG. 2, the clutch housing 31 is inserted into the clutch housing recess 21c until the fixed flange portion 31a contacts the bottom surface of the fitting recess 21b. The fixed flange portion 31 a is fixed to the plurality of fixed convex portions 21 f formed on the gear housing 21 by heat caulking. Thus, the clutch housing 31 is configured so as not to move in the axial direction and to rotate in the circumferential direction with respect to the gear housing 21. The clutch housing 31 fixed to the gear housing 21 is disposed coaxially with the rotary shaft 7 and the worm shaft 24.

  The drive-side rotator 32 is formed by insert-molding a sensor magnet 36 in the resin molding portion 40. The resin molding portion 40 has a substantially cylindrical drive shaft connecting portion 41, and the connecting portion 7a of the rotating shaft 7 is press-fitted and fixed in the drive shaft insertion hole 42 in the center of the drive shaft connecting portion 41. The drive side rotator 32 and the rotary shaft 7 are coupled so as to be integrally rotatable.

  As shown in FIGS. 2, 3, and 4 (a) and 4 (b), a sensor magnet 36 is provided on the outer periphery of the drive shaft connecting portion 41. The sensor magnet 36 has an annular shape centered on the central axis L1 of the rotating shaft 7, and the cross-sectional shape along the radial direction is rectangular. That is, the inner peripheral surface 36a and the outer peripheral surface of the sensor magnet 36 have a circular shape centered on the central axis L1 of the rotating shaft 7 when viewed from the axial direction, and both axial end surfaces of the sensor magnet 36 are orthogonal to the axial line L1. It is flat. The sensor magnet 36 is embedded in the resin molding portion 40 so that the outer peripheral surface thereof is exposed. Specifically, the resin molding portion 40 has a pair of flange portions 43 and 44 that are formed to extend radially outward from the drive shaft coupling portion 41. The pair of flange portions 43 and 44 are arranged in parallel in the axial direction of the rotary shaft 7, and the sensor magnet 36 is embedded between the pair of flange portions 43 and 44. Each of the flange portions 43 and 44 has a circular outer peripheral surface centered on the axis L1, and both end surfaces in the axial direction of the flange portions 43 and 44 have a planar shape orthogonal to the axis L1. The flanges 43 and 44 have the same diameter.

  The sensor magnet 36 is made of a plastic magnet molded with a resin material (binder) containing magnetic powder, and the resin material of the sensor magnet 36 is made of the same type of material as the resin molded portion 40 of the drive side rotating body 32. It is used. The sensor magnet 36 has both end surfaces in the axial direction fused and bonded to the inner end surfaces in the axial direction of the flange portions 43 and 44, and an inner peripheral surface 36 a is melt bonded to the outer periphery of the drive shaft connecting portion 41. This fusion bonding is performed at the time of molding the resin molding portion 40 using the sensor magnet 36 as an insert.

  As shown in FIGS. 2 and 3, the driven shaft insertion hole 45 communicated with the drive shaft insertion hole 42 is connected to the axial end portion (lower end portion in FIG. 2) of the drive shaft connection portion 41 on the speed reduction portion 2 side. And a pair of rolling element cancellation | release part 46 located in the radial direction outer side of the driven shaft insertion hole 45 is formed. The rolling element releasing portion 46 is made of an elastic material such as an elastomer different from the resin molding portion 40. The rolling element releasing portions 46 are formed at intervals of 180 ° in the circumferential direction, and extend to the side opposite to the drive shaft connecting portion 41 along the axial direction.

  The support member 33 arranged at the lower stage of the drive side rotating body 32 is formed of a resin material. The annular ring portion 51 constituting the support member 33 has an outer diameter that is equal to the outer diameter of the flange portions 43 and 44 of the drive side rotating body 32. The ring portion 51 is sandwiched between the flange portion 44 of the drive side rotating body 32 (resin molding portion 40) and the fixed flange portion 31a of the clutch housing 31 in the axial direction. In addition, the support member 33 is formed with a pair of rolling element holding portions 52 extending in the axial direction from the ring portion 51. The rolling element holders 52 are formed at intervals of 180 ° in the circumferential direction. Each rolling element holding portion 52 accommodates a cylindrical rolling element 34.

  The rolling element 34 has a cylindrical shape, and is arranged so that the central axis thereof is parallel to the axis L 1 of the rotation shaft 7. The rolling element 34 is configured to be rotatable about a central axis parallel to the axis L1. The rolling elements 34 are held at equiangular intervals (180 ° intervals in the present embodiment) in the circumferential direction.

  In a state in which the support member 33 and the drive-side rotator 32 are assembled, the rolling element release portion 46 is inserted inside the ring portion 51 and is disposed between the pair of rolling element holding portions 52 in the circumferential direction. . A gap is set between the rolling element release portion 46 and the rolling element holding portion 52 in the circumferential direction. And when the drive side rotary body 32 rotates, it is comprised so that the rolling element cancellation | release part 46 may contact | abut to the rolling element holding | maintenance part 52 in the circumferential direction.

  As shown in FIG. 2, the drive shaft coupling portion 41 and the sensor magnet 36 of the drive-side rotator 32 are disposed outside the clutch housing 31 (specifically, between the clutch housing 31 and the brush holder 10). On the other hand, the rolling element releasing part 46, the rolling element holding part 52 of the support member 33 and the rolling element 34 are inserted into the clutch housing 31. The rolling element 34 is configured such that the outer peripheral surface thereof can contact the inner peripheral surface of the clutch housing 31.

  The driven side rotator 35 is formed integrally with the base end of the worm shaft 24. On the outer peripheral surface of the driven-side rotator 35, a pair of control surfaces 35a having a planar shape parallel to the axial direction is formed. The pair of control surfaces 35a are parallel to each other. The driven-side rotator 35 is inserted between the rolling element holding portions 52 of the support member 33, and its tip is inserted into the driven shaft insertion hole 45 of the drive-side rotator 32. The control surface 35a of the driven-side rotator 35 is located inside the support member 33 and is configured to be able to contact the corresponding rolling element 34. Thereby, the rolling element 34 is interposed between the control surface 35 a and the inner peripheral surface of the clutch housing 31. Note that the distal end portion of the driven-side rotator 35 is in contact with the distal end portion of the coupling portion 7 a of the rotating shaft 7 in the axial direction inside the drive-side rotator 32.

  In the clutch 3, when a load is applied to the output shaft 28 from the load side (that is, the window glass side) when the motor unit 1 is stopped, that is, when the rotating shaft 7 and the driving side rotating body 32 are not rotated, The driven side rotating body 35 (worm shaft 24) tries to rotate. At this time, the rotation of the driven-side rotator 35 (worm shaft 24) is prevented by the interference of the rolling elements 34 disposed between the control surface 35a of the driven-side rotator 35 and the inner peripheral surface of the clutch housing 31. It has become.

  On the other hand, when the motor unit 1 is driven, that is, when the rotary shaft 7 and the driving side rotating body 32 are driven to rotate, the rolling element release unit 46 of the driving side rotating body 32 contacts the rolling element holding unit 52 of the support member 33 in the rotation direction. Touch (press). Then, the rolling element 34 is pushed out from between the inner peripheral surface of the clutch housing 31 and the control surface 35a, and the locked state by the rolling element 34 is released. In this state, the rotating shaft 7, the driving side rotating body 32, the support member 33, and the driven side rotating body 35 (worm shaft 24) rotate integrally. In this way, the rotation of the rotating shaft 7 is transmitted to the worm shaft 24.

  In the drive-side rotating body 32 of the clutch 3 described above, as shown in FIGS. 4B and 5, a pair of notch portions 36 b (positioning recesses) are formed on the inner peripheral surface 36 a of the sensor magnet 36. . The notch 36b has an arc shape that protrudes radially outward when viewed from the axial direction of the sensor magnet 36 (coincident with the axial direction of the rotary shaft 7), and extends from one axial end surface to the other end surface of the sensor magnet 36. It is formed along the axial direction.

  A part of the resin molding portion 40 of the drive side rotating body 32 is inserted into each notch portion 36b. Specifically, a rotation preventing convex portion 40a that protrudes radially outward from the outer peripheral surface of the drive shaft connecting portion 41 is inserted. An axial base end portion (upper end portion in FIG. 5) of the rotation preventing convex portion 40a is connected to the flange portion 43, and an axial front end portion extends to the axial center position of the notch portion 36b. In the cutout portion 36b, a portion where the anti-rotation convex portion 40a does not enter (the space below the anti-rotation convex portion 40a in FIG. 5) is a positioning pin 61 (see FIG. 7) described later when the resin molding portion 40 is molded. ) Is placed. Further, as described above, since the binder of the sensor magnet 36 and the resin molding portion 40 are made of the same kind of resin, the boundary surface between the notch portion 36b and the rotation preventing projection portion 40a, that is, the inner surface of the notch portion 36b. The outer surface of the non-rotating projection 40a is melt-bonded.

  The sensor magnet 36 is composed of four magnetic poles that are equally spaced in the circumferential direction. That is, the N pole and the S pole are alternately formed at 90 ° intervals. The sensor magnet 36 is made of a polar anisotropic magnet and has a material orientation (crystal orientation) corresponding to the magnetic pole. Specifically, as shown by the arrow direction in FIG. 4B, the orientation of the material of the sensor magnet 36 is set so that the N pole faces the radially outer side and the S pole faces the radially outer side. The pair of notches 36b described above are formed at equal intervals in the circumferential direction (180 ° intervals), and are formed so as to be positioned at the boundary B between the N pole and the S pole. In the present embodiment, there are four magnetic pole boundary portions B, but two of them are formed with notches 36b.

  In contrast to such a sensor magnet 36, the brush holder 10 is provided with a magnetic detecting element 13 such as a Hall element or a magnetoresistive element at a position located in the vicinity of the sensor magnet 36, as shown in FIG. . In the present embodiment, the magnetic detection element 13 is configured to face the sensor magnet 36 in the direction of the axis L1 of the rotation shaft 7. The magnetic detection element 13 is provided to detect a change in the magnetic field accompanying the rotation of the sensor magnet 36 and to detect a rotation state such as the rotation speed and rotation speed of the rotation shaft 7 (drive side rotating body 32). .

Next, the manufacturing method of the drive side rotary body 32 is demonstrated according to FIG.6 and FIG.7.
First, the sensor magnet 36 made of a plastic magnet is formed into the shape described above. Here, in FIG. 6, the orientation (crystal orientation) of the material (magnetic material) of the sensor magnet 36 is indicated by an arrow. As shown in the figure, the orientation of the material of the part that is later magnetized to the N pole faces the radially outer side, and the orientation of the material of the part that is later magnetized to the S pole faces the radially inner side. Further, the pair of notches 36b is formed at the boundary between the part that is later magnetized to the N pole and the part that is magnetized to the S pole.

  Next, an insert molding process of the sensor magnet 36 is performed. In this step, first, the sensor magnet 36 before magnetization is disposed in the first mold 60. At this time, the columnar positioning pin 61 erected on the first mold 60 is inserted into the cutout portion 36b of the sensor magnet 36 in the axial direction, and approximately half of the outer periphery of the positioning pin 61 is cutout portion 36b. Fit in. Accordingly, the sensor magnet 36 is positioned with respect to the first mold 60 in the circumferential direction (rotation direction) and the axis orthogonal direction (paper surface direction in FIG. 6). Further, as shown in FIG. 7, the tip of the positioning pin 61 is inserted to the center position in the axial direction of the notch 36b, and in this state, the sensor magnet 36 is provided on the support ( (Not shown) is supported in the axial direction.

  Next, the second mold 62 is disposed above the first mold 60, and a resin material is filled in a cavity formed by the first mold 60 and the second mold 62, and then solidified. By doing so, the resin molding part 40 is molded. At this time, the resin material enters the remaining portion 36c (the portion in which the positioning pin 61 is not inserted and the upper half of the notched portion 36b in FIG. 7) of the notched portion 36b, and the rotation preventing convex portion 40a is formed. The

  Further, since the binder of the sensor magnet 36 is made of the same kind of material as the resin molding portion 40 (a material having substantially the same melting temperature), the contact surface of the sensor magnet 36 with the resin molding portion 40 after the resin molding portion 40 is filled. (Boundary surface) is melted by the heat of the resin molding part 40 before solidification. Thereby, the boundary surface of the sensor magnet 36 and the resin molding part 40 is melt-bonded. More specifically, the boundary surface between the axial end surface of the sensor magnet 36 and the flange portions 43 and 44, the boundary surface between the inner peripheral surface 36a of the sensor magnet 36 and the outer peripheral surface of the drive shaft connecting portion 41, and the notch 36b The boundary surface with the rotation prevention convex part 40a is melt-bonded.

In addition, the rolling element cancellation | release part 46 of the resin molding part 40 is formed by the secondary molding after shape | molding the main part of the resin molding part 40. FIG.
After the above-described insert molding process, a magnetizing process is performed on the sensor magnet 36 integrally molded with the resin molded part 40. In this magnetizing step, the sensor magnet 36 is magnetized by a magnetizing coil (not shown). At this time, a magnetizing coil that imparts N pole magnetism and a magnetizing coil that imparts S pole magnetism to the sensor magnet 36 are arranged on the outer periphery of the sensor magnet 36 in accordance with the orientation of the material of the sensor magnet 36. To do. Here, since the relative position of the rotation direction of the sensor magnet 36 with respect to the resin molding portion 40 is determined at the time of the above-described insert molding step, the magnetized coil can be arranged in accordance with the orientation of the material of the sensor magnet 36. It is possible. Thereafter, a magnetic field is generated in each magnetizing coil, and the magnetism of the N pole and the S pole is imparted to the sensor magnet 36 by the magnetic field.

Next, the operation of this embodiment will be described.
In the insert molding process of the sensor magnet 36, the sensor magnet 36 is positioned in the rotational direction by the positioning pin 61 of the first mold 60 fitted into the notch 36b. Thereby, since the position of the rotation direction of the sensor magnet 36 can be grasped, when magnetizing, the magnetizing coil is disposed at a position corresponding to the orientation of the material of the sensor magnet 36 to impart magnetism to the sensor magnet 36. Is possible.

  Further, the positioning pin 61 is fitted into the notch 36b so that a part (half in the axial direction) of the notch 36b remains. Then, during the injection molding of the resin molding portion 40, the resin enters the remaining portion 36c of the notch portion 36b. Thereby, the resin (rotation prevention convex part 40a) which entered into the notch part 36b plays the role of the rotation prevention of the sensor magnet 36 after shaping | molding. For this reason, the rotation prevention convex part 40a which stops rotation of the sensor magnet 36 can be formed in the resin molding part 40 only by setting the position of the positioning pin 61 with respect to the notch part 36b (length of the positioning pin 61). It can be done.

  Further, in the portion where the notch portion 36b is formed, the amount of magnetic flux is reduced because the radial length is shorter than in other portions of the sensor magnet 36, but the magnetic pole of the sensor magnet 36 is reduced as in this configuration. By forming the notch 36b in the boundary part B of (N pole / S pole), the decrease of the magnetic flux peak (magnetic flux in the circumferential center of the magnetic pole) is suppressed as much as possible. For this reason, this configuration is advantageous when it is desired to ensure the peak of the magnetic flux, such as when the distance between the sensor magnet 36 and the magnetic detection element 13 is long.

Next, characteristic effects of the present embodiment will be described.
(1) The sensor magnet 36 made of a polar anisotropic magnet for detecting the rotation state of the driving side rotating body 32 that rotates integrally with the rotating shaft 7 (driving shaft) is connected to the driving side rotating body 32 (resin molding part 40). Are integrally formed by insert molding. The sensor magnet 36 is formed with a notch 36b (positioning recess) for positioning the sensor magnet 36 in the rotation direction. Therefore, the sensor magnet 36 is positioned in the rotation direction by the notch 36b. Is possible. As a result, the position of the sensor magnet 36 in the rotational direction can be grasped by the notch 36b. Therefore, when magnetizing, the magnetizing coil is arranged at a position corresponding to the orientation of the material of the sensor magnet 36, and the sensor magnet 36 is arranged. It is possible to impart magnetism to the material. As a result, the sensor magnet 36 integrally formed with the clutch 3 (rotation transmission device) can be constituted by a polar anisotropic magnet.

  (2) The resin molding portion 40 of the driving side rotating body 32 is formed with a rotation prevention convex portion 40a (rotation prevention portion) that enters the notch portion 36b. For this reason, in a state where the sensor magnet 36 is integrally formed with the resin molding portion 40, it is possible to prevent the position of the sensor magnet 36 in the rotational direction from being shifted. Moreover, the notch part 36b used for positioning of the sensor magnet 36 at the time of shaping | molding can also be used for the rotation stopper after shaping | molding, and simplification of a structure can be achieved.

  (3) The sensor magnet 36 is made of a plastic magnet having the same type of resin as the resin molding part 40 as a binder, and the sensor magnet 36 and the resin molding part 40 are melt-bonded. That is, by using the same kind of resin as the resin molding part 40 for the binder of the sensor magnet 36, the sensor magnet 36 and the rotating body can be melt-bonded at the time of insert molding, and the sensor magnet 36 and the resin molding part 40 are fixed. Can be strengthened.

  (4) When the sensor magnet 36 is placed in the first mold 60 as an insert, the positioning pin 61 (positioning convex portion) provided on the first mold 60 is fitted into the notch 36 b of the sensor magnet 36. Thus, the sensor magnet 36 is positioned in the rotation direction. Thereafter, a resin formed in the cavity formed by the first mold 60 and the second mold 62 is filled with the resin to mold the resin molding portion 40. Thereby, since the relative position in the rotation direction of the sensor magnet 36 with respect to the resin molding portion 40 is determined, the position in the rotation direction of the sensor magnet 36 can be grasped even in a state of being integrally molded with the resin molding portion 40. For this reason, at the time of magnetization, the magnetizing coil can be arranged at a position corresponding to the orientation of the material of the sensor magnet 36 to impart magnetism to the sensor magnet 36.

  (5) The positioning pin 61 is fitted into the notch 36b so that a part of the space in the notch 36b remains. When the resin molding part 40 is injection molded, the positioning pin 61 in the notch 36b is Resin is made to enter the remaining part (residual part 36c) that is not fitted. As a result, the resin that has entered the notch 36b plays a role of preventing rotation of the sensor magnet 36 after molding. For this reason, the rotation prevention convex part 40a which stops rotation of the sensor magnet 36 can be formed in the resin molding part 40 only by setting the position of the positioning pin 61 with respect to the notch part 36b.

  (6) A notch 36 b is formed at the boundary B of the magnetic pole of the sensor magnet 36. For this reason, the fall of the peak of the magnetic flux of the sensor magnet 36 (the magnetic flux in the circumferential center of the magnetic pole) can be suppressed. This is an advantageous configuration when it is desired to ensure the peak of the magnetic flux, such as when the distance between the sensor magnet 36 and the magnetic detection element 13 is separated.

(7) Since the notch 36 b is formed on the inner peripheral surface 36 a of the sensor magnet 36, a suitable configuration is obtained in which a decrease in magnetic flux on the outer peripheral side of the sensor magnet 36 is suppressed.
In addition, you may change embodiment of this invention as follows.

  In the above embodiment, the sensor magnet 36 has a configuration in which the magnetic flux peak is emphasized, that is, the notch 36b is formed at the boundary B of the magnetic pole of the sensor magnet 36. However, the present invention is not limited to this. You may form the notch part 36b in places other than the boundary part B (namely, circumferential direction intermediate part of a magnetic pole). For example, in the example shown in FIG. 8, the notch 36b is formed at the circumferential center of the S pole. According to such a configuration, since a decrease in magnetic flux at the magnetic pole switching portion can be suppressed, the magnetic pole switching position can be detected with high accuracy. This configuration is particularly effective in a configuration in which a magnetic flux peak is secured, such as when the distance between the sensor magnet 36 and the magnetic detection element 13 is sufficiently narrow.

  In the example shown in FIG. 8, the notch 36b is formed at the center in the circumferential direction of the S pole. However, for example, it may be formed at the center in the circumferential direction of the N pole. You may form in the position which shifted | deviated to the circumferential direction from the circumferential direction center part.

  -You may change suitably structures, such as the number of cutout parts 36b (positioning recessed part) in the said embodiment, and a shape. For example, in the above embodiment, the notch 36 b is formed on the inner peripheral surface 36 a of the sensor magnet 36, but it may be formed on the axial end surface, outer peripheral surface, or the like of the sensor magnet 36.

  In the above-described embodiment, the area occupied by the positioning pin 61 and the area occupied by the anti-rotation convex part 40a in the notch part 36b are each half of the notch part 36b in the axial direction. However, the present invention is not limited to this. Instead, for example, the length of the positioning pin 61 may be set so that the area occupied by the anti-rotation convex portion 40a is larger. Further, for example, the positioning pin 61 may have the same length as the axial length of the cutout portion 36b, and the anti-rotation convex portion 40a may be omitted.

  In the above-described embodiment, the positioning pin 61 has a columnar shape, and the shape of the cutout portion 36b viewed in the axial direction is an arc shape. However, the shape is not limited to this, and may be a rectangular cross section, for example.

  In the above embodiment, the positioning pin 61 is provided in the first mold 60 on the driven side (driven shaft insertion hole 45 side). However, the present invention is not limited to this, and the driving side (drive shaft insertion hole 42 side). ) May be provided in the second mold 62.

  In the above embodiment, the magnetizing process to the sensor magnet 36 is performed after the insert molding process. However, for example, the sensor magnet 36 may be magnetized before the insert molding. Even in this case, since the position in the rotation direction of the sensor magnet 36 can be grasped by the notch portion 36b, the magnetized coil is arranged at a position corresponding to the orientation of the material of the sensor magnet 36, and the sensor magnet 36 is magnetized. Can be granted.

  In the above embodiment, the sensor magnet 36 is formed of a plastic magnet, but other than this, for example, a sintered magnet may be used. The configuration of the sensor magnet 36 such as the shape is not limited to the above embodiment, and may be changed as appropriate.

  In the above embodiment, the outer peripheral surface of the sensor magnet 36 is exposed from the resin molding portion 40. However, the present invention is not limited to this, and the upper surface of the sensor magnet 36 (on the side of the magnetic detection element 13 in the axial direction). The end surface) may be exposed from the resin molded portion 40. In addition to the configuration of the above embodiment, the outer peripheral surface of the sensor magnet 36 may be covered with the resin molding portion 40.

  In the above embodiment, the magnetic detection element 13 is configured to face the sensor magnet 36 in the direction of the axis L1 of the rotation shaft 7, but the present invention is not limited to this. You may comprise so that it may oppose to radial direction.

  In the above embodiment, the clutch 3 as the rotation transmission device transmits the rotation of the rotation shaft 7 to the worm shaft 24, while preventing the input from the worm shaft 24 from being transmitted to the rotation shaft 7. However, the operation is not limited to this, and the configuration is not particularly limited as long as the rotation of the rotation shaft 7 is transmitted to the worm shaft 24.

  In the above embodiment, the motor for the power window device is embodied. However, the motor for another device may be embodied. Further, other than the motor, as long as a rotation transmission device that transmits the rotational force of the drive shaft to the driven shaft via the rotating body is provided, it may be embodied in another device.

Next, a technical idea that can be grasped from the above embodiment and another example will be added below.
(A) The notch is formed at a boundary portion of the magnetic pole of the sensor magnet.

  Thereby, the fall of the peak of the magnetic flux of the sensor magnet (magnetic flux in the center in the circumferential direction of the magnetic pole) can be suppressed. For this reason, when the space | interval of a sensor magnet and a magnetic detection element is separated, it can be set as an advantageous structure when it is desired to ensure the peak of magnetic flux.

(B) The cutout portion is formed in a circumferential intermediate portion of the magnetic pole of the sensor magnet.
Thereby, since the fall of the magnetic flux in the switching part of a magnetic pole is suppressed, the switching position of a magnetic pole can be detected with high precision. This configuration is particularly effective in a configuration in which a magnetic flux peak is ensured, such as when the distance between the sensor magnet and the magnetic detection element is sufficiently narrow.

Other technical ideas will be described below.
In a sensor magnet of a motor, it is conceivable to use a polar anisotropic magnet for the sensor magnet in order to strengthen the magnetic force. The polar anisotropic magnet has a material orientation (crystal orientation) corresponding to the magnetic pole. At the time of forming the sensor magnet, the orientation of the material of the sensor magnet is formed in the direction corresponding to the magnetic pole. That is, in the sensor magnet, the portion where the orientation of the material faces the outer diameter side and the portion that faces the inner diameter side are alternately formed in the rotation direction. Thereafter, the sensor magnet is magnetized to a magnetic pole corresponding to the orientation of the material. At this time, the magnetizing coil is arranged on the outer periphery of the sensor magnet, and the magnetism is imparted to the sensor magnet by the magnetic field from the magnetizing coil, but the magnetizing coil imparting N pole magnetism and the magnetism of S pole are imparted. The magnetizing coil to be used must be arranged at a position corresponding to the orientation of the material of the sensor magnet. For this reason, it was necessary to grasp the position of the sensor magnet in the rotational direction during magnetization.

  The rotation transmission device manufacturing method described below is made in order to solve the above-mentioned problem, and the purpose thereof is to rotate the sensor magnet in a configuration in which a sensor magnet made of a polar anisotropic magnet is insert-molded. It is to enable positioning in the direction.

  A resin magnet that is interposed between the drive shaft and the driven shaft and transmits the rotational force of the drive shaft to the driven shaft, and a sensor magnet for detecting the rotational state of the rotary body A method of manufacturing a rotation transmission device integrally formed by insert molding with respect to a rotating body, wherein when positioning the sensor magnet as an insert product on a mold, the positioning projection provided on the mold is The sensor magnet is positioned in the rotational direction by being fitted in a positioning recess formed on the inner peripheral surface of the sensor magnet, and then the mold is filled with resin to form the rotary body. After molding, the sensor magnet is magnetized with the positioning recess as a boundary between the magnetic poles of the sensor magnet.

  As a result, the position in the rotation direction of the sensor magnet can be grasped by the positioning recess, so that when magnetizing, the magnetizing coil is arranged at a position corresponding to the orientation of the material of the sensor magnet to impart magnetism to the sensor magnet. It becomes possible.

  In the rotation transmission device manufacturing method described above, the positioning convex portion is fitted into the positioning concave portion so that a part of the space in the positioning concave portion remains, and the positioning convex portion in the positioning concave portion is not fitted. A part of the resin constituting the rotating body is made to enter the remaining portion.

  As a result, the resin constituting the rotating body enters a part of the positioning recess (the remaining part where the positioning protrusion is not fitted), and the resin that has entered the positioning recess serves as a detent for the sensor magnet after molding. Fulfill. For this reason, the rotation prevention part which stops rotation of a sensor magnet can be formed in a rotary body only by setting the position of the positioning convex part with respect to a positioning recessed part.

  In the rotation transmission device manufacturing method described above, the sensor magnet is made of a plastic magnet having a binder of the same type of resin as the resin constituting the rotating body, and the sensor magnet and the rotating body are melt-bonded. It is characterized by.

  Thereby, the sensor magnet and the rotating body are melt-bonded at the time of insert molding by using the same kind of resin as that constituting the rotating body for the binder of the sensor magnet. For this reason, fixation with a sensor magnet and a rotary body can be strengthened.

  DESCRIPTION OF SYMBOLS 1 ... Motor part, 2 ... Deceleration part, 3 ... Clutch (rotation transmission device), 7 ... Rotating shaft (drive shaft), 13 ... Magnetic detection element, 22 ... Deceleration mechanism, 24 ... Worm shaft (driven shaft), 32 ... Drive side rotating body (rotating body), 35 ... driven side rotating body, 36 ... sensor magnet, 36b ... notch portion (positioning concave portion), 40 ... resin molded portion, 40a ... non-rotating convex portion (non-rotating portion), 60 ... 1st metal mold | die, 61 ... Positioning pin (positioning convex part), 62 ... 2nd metal mold | die.

Claims (2)

A sensor magnet that is interposed between a drive shaft and a driven shaft and transmits a rotational force of the drive shaft to the driven shaft, and detects the rotation state of the rotary body and the rotation A rotation transmission device integrally formed with the body,
A positioning recess for positioning the sensor magnet in the rotational direction is formed on the inner peripheral surface of the sensor magnet,
The rotating body is formed with a detent portion that enters the positioning recess,
The rotation transmission device, wherein the positioning recess is magnetized as a boundary part of the magnetic pole of the sensor magnet. A motor unit having a drive shaft;
A speed reduction mechanism having a driven shaft that rotates based on the rotation of the drive shaft;
A motor comprising a rotation transmission device interposed between the drive shaft and the driven shaft and transmitting the rotational force of the drive shaft to the driven shaft;
A motor using the rotation transmission device according to claim 1 as the rotation transmission device.