JP4394529B2 - Motor equipment - Google Patents

Description

  The present invention relates to a motor device, and more particularly to a motor device in which a sensor magnet is disposed on a rotating member.

Conventionally, a motor device in which a sensor magnet is disposed on a rotating member is known (see, for example, Patent Document 1). Patent Document 1 describes a motor device used for driving a power window device. In this motor device, a worm is attached to a rotating shaft of a motor, and a worm wheel as a rotating member is toothed on the worm. The combined structure.
A shaft portion is formed on the worm wheel so as to extend in the axial direction, and an annular sensor magnet is disposed on the shaft portion. A magnetic sensor is provided in the gear housing of the motor so as to face the sensor magnet.
Japanese Patent Laid-Open No. 07-0667293 (page 3, FIG. 1)

However, when the sensor magnet is disposed on the shaft portion of the rotating member as in the motor device described in Patent Document 1, it is necessary to securely fix the sensor magnet so that the sensor magnet is not displaced from the shaft portion. There was a problem that it took time to install.
Further, this type of rotating member may be formed of a synthetic resin, and there is a possibility that stress is applied to the magnet due to thermal contraction or thermal expansion of the entire worm wheel with the operation of the motor device.

Here, for example, in order to reduce the stress applied to the magnet, if the clearance between the shaft portion of the worm wheel and the magnet is increased in consideration of the effect of deformation due to thermal contraction or thermal expansion of the worm wheel, the worm wheel There is a possibility that a contact sound is generated between the magnet and the worm wheel as the rotation of the magnet moves.
In addition, it is conceivable that a magnet is attached to the shaft portion of the worm wheel with a metal annular holder interposed. However, in this case, the difference in thermal contraction or thermal expansion between the metal and the resin may occur. Since it is large, there is a gap between the holder and the worm wheel, which may make it difficult to accurately detect rotation, or the holder may be displaced from the shaft.

  The present invention has been made in view of the above circumstances, and its purpose is to easily assemble a sensor member disposed for detecting rotation of a rotating member of a motor, An object of the present invention is to provide a motor device capable of preventing problems such as displacement.

According to the present invention, there is provided a motor including a motor unit, a resin-made rotating member that is rotated by the motor unit, and a sensor unit that detects the rotation of the rotating member. In the apparatus, the rotating member is formed with a gear portion that meshes with the gear on the motor side, and a shaft portion that extends from the gear portion in the rotation axis direction of the gear portion, and the sensor portion is a detection member includes a detecting member for detecting the rotation of該被detecting member, the the outer circumferential surface of the shaft portion of the rotating member, for fixing the detection target member at a predetermined position the first engagement portion is provided, wherein the detection member includes a magnet holder which second engaging portion that engages the first engaging portion is provided, is constituted by a substantially annular sensor magnet, the The magnet holder includes a substantially annular flange portion to which the sensor magnet is fixed, and the flange. A substantially cylindrical press-fit portion extending in an axial direction from an inner peripheral end of the portion, and the magnet holder has a shaft of the rotating member in a state where the first engagement portion is inserted into the press-fit portion. The second engagement portion is formed to be capable of elastically bending in the radial direction between the slits by forming a plurality of axial slits in the press-fitting portion. It is solved by being a flexure .

As described above, in the present invention, the first engagement portion provided on the shaft portion of the rotating member and the second engagement portion provided on the detection member of the sensor portion are engaged, thereby detecting the detection target. Since the member is attached to the rotating member, even if the rotating member, which is a resin member having a large thermal expansion coefficient, is thermally expanded and contracted, the first engaging portion and the second engaging portion are engaged. Thus, the detected member can be held in a state of being securely attached to the rotating member without the detected member being displaced in the axial direction and the circumferential direction with respect to the rotating member.
Further, if the detected member is a magnet holder to which a substantially annular sensor magnet is attached, the detected member can be assembled to the shaft portion from the axial direction. In the present invention, the second engaging portion is formed as a flexible piece that can be elastically bent in the radial direction by providing an axial slit in the cylindrical press-fitting portion of the magnet holder. Since the first engaging portion is formed on the outer peripheral surface of the shaft portion so as to be engageable with the second engaging portion, the magnet holder and the shaft portion can be reliably fixed by these engagements. Further, when the magnet holder is pushed into the shaft portion during assembly, the flexible piece engages with the first engaging portion, so that alignment in the axial direction becomes easy.

At this time, one of the first engaging portion and the second engaging portion may be formed as an engaging convex portion, and the other may be formed as an engaging concave portion.
The second engagement portion is formed to be able to bend in the radial direction of the rotating member, and is configured to engage with the first engagement portion in a state of being bent in the radial direction. can do.
By comprising in this way, a to-be-detected member and a rotation member can be hold | maintained integrally reliably. In addition, it is possible to prevent the detected member from being displaced with respect to the rotating member.

  In addition, it is preferable that the first engaging portion is an engaging groove formed on the outer peripheral surface of the shaft portion so as to follow the rotation direction of the rotating member. When the first engaging portion is an engaging groove formed along the rotation direction of the rotating member, the detected member having the second engaging portion that engages with the engaging groove is moved in the axial direction. Positional displacement can be prevented, and positioning when the member to be detected is assembled to the shaft portion is facilitated.

  Furthermore, it is preferable that the engagement groove is formed on a bottom surface of a groove formed on the outer peripheral surface of the shaft portion so as to be along the axial direction of the rotating member. When the engaging groove is formed on the bottom surface of the axial groove formed on the outer peripheral surface of the shaft portion, it is easy to position the detected member and the shaft portion in the circumferential direction when the detected member is assembled to the shaft portion. In addition, since the member to be detected can be assembled to the shaft portion along this groove, the assembly is facilitated.

Furthermore, since a plurality of slits are formed in the axial direction in the press-fit portion of the magnet holder, even if the resin-made shaft portion is thermally expanded or contracted, the press-fit portion follows and bends in the radial direction as a whole. Therefore, it is possible to prevent the magnet holder from rattling against the shaft portion.
Further, even if the shaft portion is thermally expanded or contracted, the second engagement portion can be elastically bent in the radial direction, so that the engagement state between the second engagement portion and the first engagement portion can be changed. It is possible to hold.

  Furthermore, if it is set as the structure by which the protrusion part for engaging with the said 1st engaging part is formed in the front-end | tip part of the said flexible piece, by this protrusion part engaging with a 1st engaging part, Even if the rotating member rotates, the magnet holder is securely held integrally with the rotating member. Thereby, it can prevent more reliably that a magnet holder shifts | deviates to an axial direction and the circumferential direction.

In addition, according to the present invention, the above object includes a motor unit, a resin-made rotating member that is rotated by the motor unit, and a sensor unit that detects the rotation of the rotating member. In the motor device, the rotating member is formed with a gear portion that meshes with the gear on the motor side, and a shaft portion that extends from the gear portion in the rotation axis direction of the gear portion, An advancing / retracting member insertion hole is formed in the axial direction to hold the advancing / retreating member having a thread formed on the outer peripheral surface so as to be capable of advancing / retreating. And a non-thread groove forming portion where no screw groove is formed, and the sensor portion includes a detection member and a detection member that detects rotation of the detection member. It has, on the outer peripheral surface of the shaft portion of the rotating member, for fixing the detection member to a predetermined position A first engagement portion is provided, and the detected member includes a magnet holder provided with a second engagement portion that engages with the first engagement portion, and a substantially annular sensor magnet, The magnet holder includes a substantially annular flange portion to which the sensor magnet is fixed, and a substantially cylindrical press-fit portion extending in an axial direction from an inner peripheral end of the flange portion. It is attached to the thread groove non-forming part formed in the shaft part of the rotating member in a state where the first engaging part is inserted into the press-fitting part, and the second engaging part is connected to the press-fitting part, This is solved by forming a plurality of slits in the axial direction so as to be elastically bent in the radial direction between the slits .

  As described above, in the present invention, the thread groove forming portion in which the thread groove that is screwed with the thread of the advance / retreat member is formed in the advance / retreat member insertion hole of the rotating member that holds the advance / retreat member so as to be movable back and forth, and the screw groove is formed Since the non-thread groove forming portion is formed, stress is mainly applied to the screw groove forming portion during operation of the motor device, and almost no stress is applied to the screw groove non-forming portion. In the present invention, since the member to be detected of the sensor unit is attached to the non-thread groove forming part, the member to be detected of the sensor unit is hardly subjected to stress due to thermal expansion / contraction or stress applied from the outside. It is possible to prevent the detected member of the sensor unit from being damaged.

  Further, it is preferable that the non-thread groove forming portion is formed at an end portion in the axial direction of the rotating member. Thus, if the thread groove non-forming part is formed at the end of the rotating member in the axial direction, the stress applied to the thread groove non-forming part can be further reduced, so that the detected member is prevented from being damaged. Is done.

  Furthermore, it is preferable that the non-thread groove forming portion is formed to be thinner in the radial direction than the screw groove forming portion. In this way, the stress applied to the non-thread groove forming portion when the motor device is activated by forming the thickness in the radial direction of the non-thread groove forming portion thinner than the radial thickness of the screw groove forming portion. Can be eliminated, and the member to be detected is prevented from being damaged.

  In addition, it is preferable that the outer diameter of the thread groove non-forming portion is smaller than the outer diameter of the thread groove forming portion. Thus, by forming the outer diameter of the thread groove non-forming portion smaller than the outer diameter of the thread groove forming portion, the installation space of the sensor portion can be reduced, and the motor device can be downsized. Is possible.

According to the present invention, the first engagement portion and the second engagement portion that engage with the shaft portion of the rotating member and the sensor member, respectively, are formed, and the first engagement is performed when the sensor member is assembled to the shaft portion. Since the portion and the second engaging portion are engaged, the sensor member can be reliably fixed to the rotating member. Further, the engagement of the first engagement portion and the second engagement portion can prevent the sensor member from dropping or being displaced when the motor device is operated.
Furthermore, since the sensor member may be assembled to the rotating member so that the first engaging portion and the second engaging portion are engaged with each other, the alignment becomes easy and the assembling property is improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. It should be noted that members, arrangements, and the like described below do not limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.
1 to 9 relate to an embodiment of the present invention, FIG. 1 is an explanatory view of a motor device, FIG. 2 is a partially enlarged explanatory view of the motor device, FIG. 3 is an explanatory view of a sensor holder main body, FIG. 4 is a sectional view and a plan view of the worm wheel, FIG. 5 is a partially enlarged view of the worm wheel of FIG. 4, FIG. 6 is a plan view of the magnet holder, FIG. 7 is an explanatory view of the magnet holder, and FIG. 9 is an enlarged view of a part of the holder, and FIG. 9 is an explanatory view showing a mounting state of the worm wheel and the magnet holder.
FIGS. 10 to 15 relate to another embodiment of the present invention, FIGS. 10 to 13 are explanatory views showing the attachment state of the worm wheel and the magnet holder, and FIGS. 14 and 15 are shaft portions of the worm wheel. It is a partial expansion explanatory drawing of the engagement piece of a magnet holder.

First, the configuration of the motor device 1 according to an embodiment of the present invention will be described with reference to FIGS.
The motor device 1 of this example is suitably used as a motor device for driving a seat of a power seat device, for example, and as shown in FIG. 1, a motor unit 10, a speed reduction mechanism unit 20, and a sensor unit 40 and a gear housing 60 that houses the speed reduction mechanism 20 and the sensor 40 are the main components.

The motor unit 10 of this example includes a stator 12, an armature 13 having a commutator 15 disposed on one end thereof, a brush 17 that is in sliding contact with the commutator 15, and a yoke housing 11 that houses these. The yoke housing 11 is assembled to a gear housing 60 made of synthetic resin with screws 19.
The armature 13 is configured by winding a winding 16 around a core 14 fixed to a rotating shaft 13a, and is rotatably supported by a bearing. The ends of the windings 16 wound around the core 14 are connected to a commutator 15 by wiring, and brushes 17 are disposed on both sides of the commutator 15 so as to be in sliding contact with the commutator 15.

  As shown in FIGS. 1 and 2, the speed reduction mechanism unit 20 is for reducing the rotation of the motor unit 10, and includes a worm 21, a worm wheel 22 as a rotating member, and a screw 25 as an advance / retreat member. And bearing members 26, 27. The worm 21 is formed on the free end side of the rotary shaft 18 connected to the rotary shaft 13 a of the armature 13, and rotates together with the armature 13. In this example, the worm wheel 22 is used, but a helical gear may be used instead of the worm wheel 22.

The worm wheel 22 is made of synthetic resin, and as shown in FIG. 2, the disk-shaped gear portion 23 having teeth along the circumferential direction and the gear portion 23 along the axial direction of the rotation axis (Lc). And a cylindrical shaft portion 24 formed so as to extend in the vertical direction.
The gear portion 23 is accommodated in the recess 61 b formed in the gear housing 60 while being sandwiched between the bearing members 26 and 27 and meshed with the worm 21. As a result, the worm wheel 22 rotates about the rotation axis Lc as the worm 21 rotates.

  As will be described later, the worm wheel 22 is formed with a screw insertion hole 24a as an advance / retreat member insertion hole so as to penetrate in the axial direction, and the screw 25 is inserted into the screw insertion hole 24a. On the inner wall of the screw insertion hole 24a, a screw groove that is screwed into a screw thread formed on the outer peripheral surface of the screw 25 is formed. In the motor apparatus 1 of this example, the worm wheel 22 rotates via the worm 21 when the motor unit 10 operates. The screw 25 is moved forward and backward in the axial direction by the rotation of the worm wheel 22.

2 and 3, the sensor unit 40 includes a sensor holder body 41, a rotation detector 42 attached to the sensor holder body 41, a magnet holder 50 attached to the end of the shaft part 24, An annular sensor magnet 43 fixed to the magnet holder 50 is a main component. The magnet holder 50 and the sensor magnet 43 correspond to detected members, and the rotation detector 42 corresponds to a detection member.
The sensor holder main body 41 is screwed from the outside so as to be partially fitted into the second gear housing 62 and is fixed to the second gear housing 62. The sensor holder main body 41 is formed with a through hole 41a through which the screw 25 is inserted at a central portion, and a connector portion 41b is formed on a side portion.

The sensor magnet 43 is formed in an annular shape and is magnetized so that the magnetic force is directed in the radial direction. Further, N poles and S poles are alternately formed in the circumferential direction. In this example, two N poles and two S poles are formed.
The sensor magnet 43 is fixed to the end portion of the shaft portion 24 while being attached to the cylindrical magnet holder 50. The magnet holder 50 is attached to the shaft portion 24 by being press-fitted into the end portion.

The rotation detector 42 of this example uses a Hall element. The rotation detector 42 detects a change in magnetic force from the sensor magnet 43 that rotates together with the shaft portion 24 and sends a detection signal. is doing.
The rotation detector 42 is electrically connected to a connector terminal 45 held in the connector portion 41b via a terminal plate 44. The rotation detector 42 is attached to the sensor holder main body 41 so as to face the sensor magnet 43 at a predetermined distance in a state where the magnet holder 50 is attached to the shaft portion 24. The rotation detector 42 may not be attached to the sensor holder main body 41 and may be attached to the first gear housing 61 or the second gear housing 62.

The gear housing 60 is for housing the speed reduction mechanism unit 20 and includes a first gear housing 61 and a second gear housing 62. The gear housing 60 is assembled to the power seat device in a state where the gear housing 60 is sandwiched between two opposing flat portions 70 a and 70 b of the U-shaped bracket 70.
As shown in FIGS. 1 and 2, the first gear housing 61 accommodates a part of the worm 21, the worm wheel 22, and the shaft portion 24. A recess 61b is formed in the first gear housing 61 so as to have an opening on the side opposite to the end portion 61a, and the gear portion 23 and the bearing members 26 and 27 are accommodated in the recess 61b.

The second gear housing 62 is assembled to the first gear housing 61 with screws so as to close the opening 61c of the recess 61b. The second gear housing 62 is formed with an accommodating recess 62b for accommodating the sensor unit 40 described above. The sensor magnet 43 is rotatable with the rotation of the shaft portion 24 in a state of facing the rotation detector 42 in the housing recess 62b.
The second gear housing 62 is formed with a power supply connector 63 for receiving power supply from the outside, and a power supply terminal disposed in the power supply connector 63 is electrically connected to the brush 17. .

Next, the worm wheel 22 of this example will be described based on FIGS. 4 and 5.
4A is a cross-sectional view of the worm wheel 22, and FIG. 4B is a view of the worm wheel 22 as viewed from the second gear housing 62 side.
As shown in FIG. 4A, a screw insertion hole 24a that penetrates along the axial direction is formed in the central portion of the shaft portion 24 of the worm wheel 22. The shaft part 24 includes a thread groove forming part 24A and a thread groove non-forming part 24B. In the screw groove forming portion 24A, a screw groove that is screwed into the screw thread of the screw 25 is formed in the screw insertion hole 24a on the inner wall, and in the screw groove non-forming portion 24B, a screw groove is formed in the screw insertion hole 24a. Not.
A gear portion 23 is formed in the thread groove forming portion 24A. Further, the magnet holder 50 to which the sensor magnet 43 is fixed is assembled to the non-thread groove forming portion 24B (see FIG. 9).

  The thread groove non-forming portion 24B is formed at the upper end portion (the end portion on the second gear housing 62 side) of the shaft portion 24, and protrudes into the accommodating recess 62b. Further, the outer diameter of the thread groove non-forming portion 24B is formed to be smaller than the outer diameter of the thread groove forming portion 24A. On the other hand, the inner diameter of the thread groove non-forming portion 24B is formed so as to be larger than the inner diameter of the thread groove forming portion 24A. A space is provided between the non-formed portion 24B and the inner surface of the non-formed portion 24B so that the stress from the screw 25 is hardly transmitted to the non-formed groove portion 24B.

Further, since the magnet holder 50 is attached to the outer surface in the radial direction of the non-thread groove forming portion 24B that is axially separated from the screw groove forming portion 24A that is screwed with the screw 25, the worm The stress transmitted from the wheel 22 to the magnet holder 50 can be reduced.
Further, the thickness in the radial direction of the thread groove non-forming portion 24B is formed to be thinner than the thickness of the thread groove forming portion 24A. Thereby, the influence of the stress applied to the screw 25 is prevented from reaching the magnet holder 50 disposed in the non-thread groove forming portion 24B.

The thread groove non-forming portion 24B is formed with a plurality of engaging portions 24Ba as first engaging portions along the circumferential direction. In this example, the engaging portions 24Ba are formed at four locations at intervals of approximately 90 degrees in the circumferential direction. However, the present invention is not limited to this, and one or more engaging portions 24Ba may be formed. As will be described later, the engaging portion 24Ba is used for alignment when the magnet holder 50 is press-fitted. By providing a large number of engaging portions 24Ba, the positioning rotation angle can be reduced. The attachment is further improved. FIG. 5 shows an enlarged view of the vicinity of the engaging portion 24Ba.
The engaging portion 24Ba includes a groove portion 24Bb (corresponding to a guide groove) for guiding an engaging piece 50a (corresponding to a second engaging portion) which is a flexible piece formed on a magnet holder 50 described later, and An engaging groove 24Bc that fits into an engaging convex portion 50b (corresponding to a protruding portion) formed in the magnet holder 50 is formed.

As shown in FIG. 5B, the groove 24Bb is formed on the upper portion of the outer periphery of the non-thread groove portion 24B. The groove portion 24Bb is formed such that the outer peripheral side of the upper portion of the thread groove non-forming portion 24B is cut out by a predetermined angular width so as to be parallel to the inner peripheral surface. The angular width in the circumferential direction of the groove 24Bb is set to about 15 degrees in this example.
The engagement groove 24Bc is formed on the bottom (screw 25 side) of the groove 24Bb so as to extend in the circumferential direction. In this example, the engagement groove 24Bc is formed slightly above the center of the groove part 24Bb in the vertical direction. As shown in FIG. 5B, the engagement groove 24Bc is a groove having a substantially semicircular cross section. The engagement groove 24Bc is not limited to a substantially semicircular cross section, and may be a rectangular cross section, a triangular cross section, or the like.

Next, the magnet holder 50 of this example will be described. The magnet holder 50 of this example is made of metal, and as shown in FIGS. 6 to 8, a substantially cylindrical shape integrally formed so as to stand up from an annular flange portion 51 and an inner end portion of the flange portion 51. The press-fitting portion 52 is provided. The magnet holder 50 is formed by punching or bending.
The press-fit portion 52 is formed so that the inner diameter of the upper portion 52a is smaller than the inner diameter of the lower portion 52b on the flange portion 51 side. In this example, a stepped portion 52c is formed between the lower portion 52b and the upper portion 52a.

The inner diameter of the upper portion 52a is slightly smaller than the outer diameter of the non-thread groove formed portion 24B. When the magnet holder 50 is inserted into the non-thread groove formed portion 24B from above, the upper portion 52a and the screw groove are formed. The non-forming part 24B is fixed in a press-fitted state. At this time, a space S1 is formed between the lower portion 52b and the non-thread groove forming portion 24B. The space S1 can absorb the radial expansion when the worm wheel 22 is thermally expanded.
The outer diameter of the lower part 52 b is formed smaller than the diameter of the through hole of the annular sensor magnet 43, and the press fit part 52 of the magnet holder 50 is inserted into the through hole of the sensor magnet 43 so that the sensor magnet When 43 is attached to the flange portion 51 of the magnet holder 50, a space S2 is formed between the inner peripheral surface of the sensor magnet 43 and the outer peripheral surface of the press-fit portion 52. In this example, the sensor magnet 43 and the flange portion 51 are joined using an adhesive.

  When the press-fit portion 52 is press-fitted into the non-thread groove forming portion 24B, a deformation force is applied to the upper portion 52a. However, since the space S2 is formed between the press-fit portion 52 and the sensor magnet 43, the deformation force is It is absorbed by the space S2 and the deformation force is prevented from being transmitted to the sensor magnet 43, and the sensor magnet 43 is prevented from being damaged.

  In the magnet holder 50 of this example, four positioning convex portions 52d are formed on the outer peripheral surface of the lower portion 52b. The positioning convex portion 52d protrudes from the outer peripheral surface of the lower portion 52b so as to have a predetermined length in the axial direction. On the other hand, on the inner wall surface of the annular sensor magnet 43, an axially extending groove (not shown) that engages with the positioning convex portion 52d is formed. When the sensor magnet 43 is attached to the magnet holder 50, the positioning can be easily performed by the positioning convex portion 52d being engaged with the groove. In addition, since the positioning convex portion 52d and the groove that engages with the positioning convex portion 52d are formed, in the magnet holder 50 of the present example, the circumferential displacement from the sensor magnet 43 is prevented.

Further, a plurality of engagement pieces 50 a are formed on the upper side of the press-fit portion 52. In this example, engagement pieces 50a are formed at four locations in the circumferential direction. The engaging pieces 50a are engaged with the engaging portions 24Ba formed on the shaft portion 24, and are formed at intervals of about 90 degrees in the circumferential direction and at an angular width of about 15 degrees. Each engagement piece 50a is formed between two slits 52e extending in the axial direction from the upper end of the press-fit portion 52. Therefore, the engagement piece 50a can be elastically bent in the radial direction of the rotating shaft independently of the other side surface portion of the press-fit portion 52. Also, the press-fit portion 52 other than the engagement piece 50a sandwiched between the slits 52e can be bent in the radial direction.
Thus, in the magnet holder 50 of this example, since the slit 52e is formed in the press-fit part 52, the bending allowance of the press-fit part 52 can be set large. As a result, even if the metal magnet holder 50 having a smaller thermal expansion and thermal shrinkage than the resin is assembled to the resin worm wheel 22 having a large thermal expansion and thermal contraction, the press-fit portion 52 is made of the resin worm. It is possible to follow the thermal expansion and contraction of the wheel 22. Therefore, rattling of the magnet holder 50 press-fitted and fixed to the worm wheel 22 can be prevented.

An engaging convex portion 50b (corresponding to a protruding portion) having a substantially semicircular cross section is formed at the upper end portion of the engaging piece 50a (see FIG. 7). The engaging convex portion 50b is provided so as to protrude in the axial center direction. The engaging piece 50a is slightly inclined as a whole in the axial center direction.
In order to attach the magnet holder 50 to the shaft portion 24 of the worm wheel 22, first, the magnet holder 50 is held so that the flange portion 51 faces down, the magnet holder 50 is aligned in the circumferential direction, and the engagement piece 50a is arrange | positioned so as to oppose the engaging part 24Ba of the thread groove non-formation part 24B. In this state, the magnet holder 50 is inserted toward the thread groove non-forming part 24B from the upper part (second gear housing 62 side) of the thread groove non-forming part 24B.

When inserted in this manner, the upper portion 52a of the press-fit portion 52 and the non-thread groove formed portion 24B are in a press-fit state, and the magnet holder 50 is fixed to the non-thread groove formed portion 24B.
At this time, since the engaging piece 50a is guided by the groove 24Bb of the engaging portion 24Ba, it is easy to assemble and the magnet holder 50 is prevented from shifting in the circumferential direction. When the magnet holder 50 is pushed down to a predetermined depth in the axial direction, the engagement convex portion 50b formed at the tip portion of the engagement piece 50a is engaged with the engagement groove 24Bc. When the engaging protrusion 50b is engaged with the engaging groove 24Bc, axial alignment can be performed. In this way, the magnet holder 50 can be attached to the shaft portion 24 of the worm wheel 22.
When the magnet holder 50 is attached to the shaft portion 24 of the worm wheel 22, the engaging piece 50a is engaged with the groove portion 24Bb and the engaging convex portion 50b is engaged with the engaging groove 24Bc. In a state where the magnet holder 50 is positioned, it can be reliably fixed to the non-thread groove forming portion 24B.

As described above, the shaft portion 24 of the worm wheel 22 of the present example is formed with the groove portion 24Bb and the engagement groove 24Bc, and in accordance with this, the magnet holder 50 has the engagement piece provided with the engagement convex portion 50b. 50a is formed. With such a configuration, when the magnet holder 50 is attached to the shaft portion 24 of the worm wheel 22, the engagement piece 50a is fitted into the groove portion 24Bb to prevent the circumferential shift and the engagement groove 24Bc. The engagement convex portion 50b is fitted into the circumferential portion, thereby preventing the circumferential and axial shifts.
Further, when the magnet holder 50 is assembled to the shaft portion 24 of the worm wheel 22, the groove portion 24Bb serves as a guide for positioning the magnet holder 50, so that the assembling property is improved.

  Further, as shown in FIG. 7, the depth B in the radial direction of the groove portion 24Bb formed in the non-thread groove forming portion 24B is the protrusion dimension A of the engaging convex portion 50b (the thickness in the radial direction of the engaging convex portion 50b). It is set to be larger than When assembling, the position of the portion where the groove portion 24Bb is formed and the portion where the engaging piece 50a is formed are aligned, and the magnet holder 50 is fitted into the non-thread groove forming portion 24B. The joint convex part 50b contacts the groove part 24Bb and bends radially outward. However, since the depth B of the groove 24Bb is set to be larger than the protruding dimension A of the engaging convex portion 50b, the engaging convex portion 50b even if the engaging convex portion 50b is bent outward in the radial direction. The radially outer portion of the sensor magnet 43 does not interfere with the inner wall surface of the sensor magnet 43, and the inconvenience that the sensor magnet 43 is excessively stressed or damaged can be avoided.

  Further, since interference between the engagement piece 50a and the sensor magnet 43 can be prevented during assembly, there is no need to set a large distance between the inner peripheral surface of the sensor magnet 43 and the press-fit portion 52. For this reason, since the diameter of the through hole of the sensor magnet 43 can be set to be small to some extent, the magnetic force applied to the rotation detector 42 can be secured without setting the outer diameter of the sensor magnet 43 to be large. Thereby, the outer diameter dimension of the sensor magnet 43 can be set smaller. Alternatively, when the outer diameter of the sensor magnet 43 is the same, the grade can be lowered to a magnet having a small magnetic flux density, and the manufacturing cost can be reduced.

Next, operation | movement of the motor apparatus 1 of this example is demonstrated.
In the motor apparatus 1 of this example, by operating an operation switch (not shown), the motor unit 10 is driven to rotate, and the worm 21 rotates. When the worm 21 rotates, the worm wheel 22 that meshes with the worm 21 rotates, and the screw 25 moves forward and backward accordingly. At this time, the rotation of the worm wheel 22 is detected by the sensor unit 40. That is, the rotation of the worm wheel 22 is detected by detecting the change in the magnetic field by the sensor magnet 43 that rotates integrally with the worm wheel 22 by the rotation detector 42. With this detection signal, a control unit (not shown) can monitor the protruding position of the screw 25.
The sensor magnet 43 of this example is fixed to the magnet holder 50, and the magnet holder 50 is fixed to the thread groove non-forming portion 24 </ b> B of the shaft portion 24. The engaging piece 50a formed on the magnet holder 50 is elastically engaged with the groove 24Bb formed on the non-thread groove forming portion 24B. Therefore, even if the worm wheel 22 rotates, the magnet holder 50 is held without causing a positional shift in the worm wheel 22 due to the engagement between the engagement piece 50a and the groove 24Bb. Therefore, the rotation of the worm wheel 22 can be detected with high accuracy and high reliability.
Further, since the engaging convex portion 50b is elastically engaged with the engaging groove 24Bc formed in the non-thread groove forming portion 24B, the magnet holder 50 is securely fixed to the shaft portion 24 and is axially moved. It can prevent shifting.

  In the motor device 1 of the present example, the engagement piece 50a and the groove portion 24Bb, and the engagement convex portion 50b and the engagement groove 24Bc are fitted, thereby shifting the position of the magnet holder 50 to which the sensor magnet 43 is attached. It becomes possible to prevent reliably. Therefore, when the motor apparatus 1 is operated, the magnet holder 50 and the sensor magnet 43 can be reliably held at positions where they are not subjected to the pressure from the bracket 70.

  In the motor device 1 of this example, the outer diameter of the non-thread groove forming portion 24B where the magnet holder 50 is disposed is configured to be smaller than the outer diameter of the screw groove forming portion 24A. Thereby, the magnet holder 50 and the sensor magnet 43 can be reduced in size, and the arrangement space for the sensor-related members including the rotation detector 42 can be reduced.

The embodiment of the present invention can be modified as follows.
In the above embodiment, the shape of the engagement piece 50a formed on the magnet holder 50 is a shape having a cross section shown in FIG. That is, the cross section of the engagement convex portion 50b formed at the tip end portion of the engagement piece 50a is formed to have a substantially semicircular shape. However, the present invention is not limited to this. In addition, like the magnet holder 150 shown in FIG. 10, the part formed in the front-end | tip part of the engagement piece 150a may be comprised as the latching claw 150b which can be hooked in the engagement groove 24Bc. .

  In the above embodiment, the thread groove non-forming portion 24B is formed with the groove portion 24Bb along the axial direction of the rotation shaft of the worm wheel 22, but the present invention is not limited to this. . In addition, as shown in FIG. 11, only the engagement groove 124 </ b> Bc for engaging the engagement protrusion 50 b of the magnet holder 50 may be formed without forming the groove 24 </ b> Bb.

  In the above embodiment, the engagement groove 24Bc having a substantially semicircular cross section is formed on the outer peripheral surface of the non-thread groove forming portion 24B in order to engage with the engagement convex portion 50b of the magnet holder 50. However, the present invention is not limited to this. In addition, as shown in FIG. 12, a through hole 24Bd may be formed in the radial direction from the bottom of the groove 24Bb to the inner peripheral surface, and the through hole 24Bd may be engaged with the engaging convex portion 50b. The dimension in the axial direction of the through hole 24Bd is preferably formed to be approximately the same as the dimension in the axial direction of the engaging convex portion 50b so that the engaging convex portion 50b is fitted.

  In the above embodiment, the thread groove non-forming portion 24B is formed with the engaging portion 24Ba as the first engaging portion, and the magnet holder 50 is formed with the engaging piece 50a as the second engaging portion. The engaging piece 50a is configured to fit into the engaging portion 24Ba. However, the present invention is not limited to this, and as shown in FIG. The holder 50 may be provided with an engagement recess 50c into which the protrusion 24Be is fitted. In the example of FIG. 13, the protrusion 24Be is provided so as to protrude in the radial direction from the bottom of the groove 24Bb, and has a substantially semicircular cross section. Further, the engagement recess 50c is deformed so that the vicinity of the end of the engagement piece 50a protrudes in a substantially semicircular cross section toward the outside in the radial direction, thereby forming a substantially semicircular cross section inside the engagement piece 50a. Are formed as recesses.

  In the above embodiment, the engaging convex portion 50b and the engaging groove 24Bc are each formed to have an angular width substantially equal to the width of the groove portion 24Bb. However, the present invention is not limited to this. is not. In addition, as shown in FIG. 14, an engaging convex portion 250b having a circumferential width smaller than the angular width of the groove 24Bb is protruded radially inward in the vicinity of the end of the engaging piece 50a. It may be formed. Further, a through-hole 124Bd having a circumferential width smaller than the angular width of the groove 24Bb may be formed at the bottom of the groove 24Bb so as to engage with the engagement convex portion 250b. In FIG. 14, the through hole 124Bd is formed to engage with the engaging convex portion 250b. However, in order to engage with the engaging convex portion 250b, the bottom of the groove portion 24Bb extends to the inner peripheral surface of the shaft portion 24B. Of course, grooves or recesses that do not penetrate may be formed.

  Further, as shown in FIG. 15, a through hole 150c having a circumferential width smaller than the angular width of the groove 24Bb is provided near the end of the engagement piece 50a, and the bottom of the groove 24Bb is larger than the angular width of the groove 24Bb. A convex portion 124Be having a small circumferential width and engaging with the through hole 150c may be formed. In FIG. 15, the through hole 150c is formed at the end of the engagement piece 50a. However, the present invention is not limited to this, and a recess is formed at the end of the engagement piece 50a as long as it can be engaged with the protrusion 124Be. May be. That is, a recess that is recessed outward in the radial direction may be formed near the end of the engagement piece 50a.

It is explanatory drawing of the motor apparatus which concerns on one Embodiment of this invention. It is a partially expanded explanatory view of a motor device according to an embodiment of the present invention. It is explanatory drawing of the sensor holder main body which concerns on one Embodiment of this invention. It is sectional drawing and the top view of the worm wheel which concern on one Embodiment of this invention. FIG. 5 is a partially enlarged view of the worm wheel in FIG. 4. It is a top view of the magnet holder which concerns on one Embodiment of this invention. It is explanatory drawing of the magnet holder which concerns on one Embodiment of this invention. FIG. 7 is a partially enlarged view of the magnet holder of FIG. 6. It is explanatory drawing which shows the attachment state of the worm wheel and magnet holder which concern on one Embodiment of this invention. It is explanatory drawing which shows the attachment state of the worm wheel and magnet holder which concern on other embodiment of this invention. It is explanatory drawing which shows the attachment state of the worm wheel and magnet holder which concern on other embodiment of this invention. It is explanatory drawing which shows the attachment state of the worm wheel and magnet holder which concern on other embodiment of this invention. It is explanatory drawing which shows the attachment state of the worm wheel and magnet holder which concern on other embodiment of this invention. It is the elements on larger scale of the engaging part of the axial part of the worm wheel which concerns on other embodiment of this invention, and a magnet holder. It is the elements on larger scale of the engaging part of the axial part of the worm wheel which concerns on other embodiment of this invention, and a magnet holder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Motor device, 10 ... Motor part, 11 ... Yoke housing, 12 ... Stator, 13 ... Armature, 13a ... Rotating shaft, 14 ... Core, 15 ... Commutator, 16 ... winding, 17 ... brush, 18 ... rotating shaft, 19 ... screw, 20 ... deceleration mechanism, 21 ... worm, 22 ... worm wheel ( Rotating member), 23 ... gear part, 24 ... shaft part, 24a ... screw insertion hole (advancing / retracting member insertion hole), 24A ... screw groove forming part, 24B ... no thread groove forming Part, 24Ba ... engaging part (first engaging part), 24Bb ... groove part (guide groove), 24Bc ... engaging groove, 24Bd ... through hole, 24Be ... convex part, 25 ... Screw, 26,27 ... Bearing member, 40 ... Sensor part, 41 ... Supporter body, 41a ... through hole, 41b ... connector, 42 ... rotation detector (detection member), 43 ... sensor magnet (detected member), 44 ... terminal plate, 45. ..Connector terminals, 50... Magnet holder (detected member), 50a... Engaging piece (second engaging portion), 50b... Engaging convex portion (projecting portion), 50c. Joint recess, 51 ... flange, 52 ... press fit, 52a ... upper, 52b ... lower, 52c ... step, 52d ... positioning projection, 52e ... slit, 60 ... gear housing, 61 ... first gear housing, 62 ... second gear housing, 61a ... end, 61b ... recess, 61c ... opening, 62b ... receiving recess 63 ... Power supply connector, 70 ... Bracket , 70a, 70b ... plane portion, 124Bc ... engaging groove, 124Bd ... through hole, 124Be ... convex portion, 150 ... magnet holder, 150a ... engaging piece, 150b ... Locking claw, 150c ... through hole, 250b ... engagement projection, Lc ... rotation axis, S1, S2 ... space

Claims (10)

In a motor device comprising a motor unit, a resin-made rotating member rotated by the motor unit, and a sensor unit for detecting the rotation of the rotating member,
The rotating member is formed with a gear portion that meshes with the gear on the motor side, and a shaft portion that extends from the gear portion in the rotation axis direction of the gear portion ,
The sensor unit includes a detection member and a detection member that detects rotation of the detection member;
Wherein the outer peripheral surface of the shaft portion of the rotating member, the first engagement portion for fixing the detection target member at a predetermined position is provided,
Wherein the detection member includes a magnet holder which second engaging portion that engages the first engaging portion is provided, it is constituted by a substantially annular sensor magnet,
The magnet holder includes a substantially annular flange portion to which the sensor magnet is fixed, and a substantially cylindrical press-fit portion extending in an axial direction from an inner peripheral end of the flange portion. It is attached to the shaft portion of the rotating member in a state where the first engaging portion is inserted into the press-fit portion,
The second engaging portion is a flexible piece formed to be capable of elastically bending in the radial direction between the slits by forming a plurality of axial slits in the press-fitting portion. A motor device characterized by the above.   2. The motor device according to claim 1, wherein one of the first engaging portion and the second engaging portion is formed as an engaging convex portion and the other is formed as an engaging concave portion.   The second engaging portion is formed so as to be able to bend in the radial direction of the rotating member, and is engaged with the first engaging portion in a state of being bent in the radial direction. The motor device according to claim 1.   2. The motor device according to claim 1, wherein the first engagement portion is an engagement groove formed on an outer peripheral surface of the shaft portion along a rotation direction of the rotation member.   The motor device according to claim 4, wherein the engagement groove is formed on a bottom surface of a groove formed on the outer peripheral surface of the shaft portion so as to be along the axial direction of the rotating member. Wherein the distal end of the flexible piece, a motor apparatus according to claim 1, characterized in that the projections for engaging the first engaging portion is formed. In a motor device comprising a motor unit, a resin-made rotating member rotated by the motor unit, and a sensor unit for detecting the rotation of the rotating member,
The rotating member is formed with a gear portion that meshes with the gear on the motor side, and a shaft portion that extends from the gear portion in the rotation axis direction of the gear portion, and has a thread on the outer peripheral surface. An advancing / retracting member insertion hole for holding the advancing / retreating member formed so as to be capable of advancing / retreating is formed in the axial direction
In the advance / retreat member insertion hole, a thread groove forming portion in which a thread groove to be screwed with a thread of the advance / retreat member is formed, and a thread groove non-forming portion in which no screw groove is formed,
The sensor unit includes a detection member and a detection member that detects rotation of the detection member;
A first engaging portion for fixing the detected member at a predetermined position is provided on the outer peripheral surface of the shaft portion of the rotating member,
The detected member includes a magnet holder provided with a second engaging portion that engages with the first engaging portion, and a substantially annular sensor magnet,
The magnet holder includes a substantially annular flange portion to which the sensor magnet is fixed, and a substantially cylindrical press-fit portion extending in an axial direction from an inner peripheral end of the flange portion. It is attached to the thread groove non-forming part formed in the shaft part of the rotating member in a state where the first engaging part is inserted into the press-fitting part ,
The second engaging portion is a flexible piece formed to be capable of elastically bending in the radial direction between the slits by forming a plurality of axial slits in the press-fitting portion. A motor device characterized by the above. The motor device according to claim 7 , wherein the thread groove non-forming portion is formed at an end portion in an axial direction of the rotating member. The motor device according to claim 7 , wherein the screw groove non-forming portion is formed to have a smaller radial thickness than the screw groove forming portion. The motor device according to claim 7 , wherein an outer diameter of the thread groove non-forming portion is smaller than an outer diameter of the thread groove forming portion.

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