JP2020191702A - Power transmission device and door mirror device - Google Patents

Abstract

To provide a power transmission device which suppresses generation of sound during motor rotation by suppressing backlash between a motor and a worm, and a door mirror device including the power transmission device.SOLUTION: A power transmission device comprises: a case 2; a motor 3 which is supported by the case 2 and includes a rotary shaft 32; a resin worm 4 which includes an insertion art 43 to which the rotary shaft 32 is inserted, and transmits drive power of the motor 3 to an external device (worm wheel 16). In the power transmission device, the worm 4 includes: a cylindrical body 5 which is provided in the insertion part 43 and disposed between the rotary shaft 32 and the worm 4; and a transmission part 46 to which rotation of the rotary shaft 32 is transmitted. A door mirror device comprises: a door mirror support part which is provided at a vehicle body side; and a door mirror body which is rotated with respect to the door mirror support part. The power transmission device is provided in the door mirror body.SELECTED DRAWING: Figure 3

Description

The present invention relates to a power transmission device and a door mirror device.

Conventionally, it is known that a worm is connected to an end of a rotating shaft of a motor.

For example, Patent Document 1 describes an electric storage unit (motor unit) for rotationally driving a door mirror, wherein the motor unit includes a motor, a worm connected to a rotating shaft of the motor, and a case for accommodating the motor and the worm. A configuration is disclosed that includes a worm wheel that meshes with the worm. According to the technique described in Patent Document 1, the rotation of the motor is transmitted to the worm, and the shaft of the door mirror rotates via a plurality of gears connected to the worm, so that the entire door mirror rotates with the shaft as the rotation axis. Move.

Japanese Unexamined Patent Publication No. 2010-11132

These worms may be provided with an insertion portion for inserting the rotation shaft of the motor. Here, for example, when the worm is formed by injection molding, the dimensional accuracy of the insertion portion is lowered due to the sink mark of the resin, so it is necessary to set the inner diameter of the insertion portion to be larger than the rotation shaft of the motor. However, if the inner diameter of the insertion portion is set to be large, a clearance is generated between the insertion portion and the rotating shaft, which causes rattling between the motor and the worm, which may cause noise when the motor is rotated. is there.

Therefore, the present invention provides a power transmission device that suppresses the generation of sound when the motor rotates by suppressing rattling between the motor and the worm, and a door mirror device having this power transmission device. ..

In order to solve the above problems, the power transmission device according to the present invention has a case, a motor having a rotating shaft supported by the case, and an insertion portion into which the rotating shaft is inserted. In a power transmission device including a resin worm that transmits a driving force to an external device, the worm is provided in the insertion portion and is arranged between the rotation shaft and the worm. It is characterized by having a transmission unit through which the rotation of the rotation shaft is transmitted.

In the power transmission device according to the present invention, the transmission unit is characterized in that it comes into contact with the tip end portion of the rotation shaft in the circumferential direction of the rotation shaft.

The power transmission device according to the present invention is characterized in that the tubular body is formed of a metal material and is arranged in the insertion portion in a state of being integrally formed with the worm by insert molding.

The power transmission device according to the present invention is characterized in that the tubular body is formed of a member separate from the worm and is arranged in the insertion portion in a state of being press-fitted into the insertion portion.

The door mirror device according to the present invention is characterized in that the above-mentioned power transmission device is provided in the door mirror main body.

According to the present invention, it is possible to provide a power transmission device that suppresses the generation of sound when the motor rotates by suppressing rattling between the motor and the worm, and a door mirror device having the power transmission device.

The perspective view of the door mirror device which concerns on 1st Embodiment. The cross-sectional view of the power transmission device which concerns on 1st Embodiment. FIG. 2 is an enlarged view of Part III. The side view of the motor which concerns on 1st Embodiment. The perspective view of the worm which concerns on 1st Embodiment. The cross-sectional view of the power transmission device which concerns on 2nd Embodiment.

Next, an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment)
(Door mirror device)
FIG. 1 is a perspective view of the door mirror device 10 according to the first embodiment.
The door mirror device 10 is provided, for example, on the vehicle body of an automobile. The door mirror device 10 includes a door mirror support portion 11 provided on the side of the vehicle body, and a door mirror main body 12 that rotates with respect to the door mirror support portion 11.
The door mirror main body 12 rotates around the axis O along the vertical direction of the vehicle body with respect to the door mirror support portion 11. The door mirror main body 12 includes a cylindrical member support device 15 provided along the axis O, and a power transmission device 1 that rotates around the cylindrical member support device 15.

The cylindrical member support device 15 is housed inside the door mirror main body 12. The cylindrical member support device 15 is formed in a cylindrical shape coaxial with the axis O. In the cylindrical member support device 15, wiring (not shown) electrically connected to a motor or the like for driving the door mirror main body 12 is arranged inside the cylinder, and the clutch gear 14 is fixed to the outside of the cylinder. ing.
The end portion of the cylindrical member support device 15 located on the lower side in the vertical direction is connected to the door mirror support portion 11. As a result, the door mirror support portion 11 and the door mirror main body 12 are connected via the cylindrical member support device 15.
A clutch gear 14 is fixed to the cylindrical member support device 15. The clutch gear 14 is provided coaxially with the axis O. A plurality of gear portions are provided on the outer peripheral portion of the clutch gear 14.

(Power transmission device)
A power transmission device 1 is connected to the cylindrical member support device 15 via a worm gear (not shown) that meshes with the clutch gear 14 and a worm wheel 16 that rotates integrally with the worm gear. The power transmission device 1 is housed inside the door mirror main body 12. The power transmission device 1 has a drive source (motor 3) inside, and the driving force generated by the drive source is transmitted to the worm wheel 16 and the worm gear (not shown), so that the axis line with respect to the cylindrical member support device 15. Rotate around O.
FIG. 2 is a cross-sectional view of the power transmission device 1 according to the first embodiment. FIG. 3 is an enlarged view of Part III of FIG.
The power transmission device 1 includes a case 2, a motor 3 and a worm 4 housed in the case 2, and a tubular body 5 (see FIG. 3) arranged between the motor 3 and the worm 4.

(Case)
As shown in FIG. 2, the case 2 is formed in a box shape having a space inside. The case 2 has a motor accommodating portion 21 located on the upper side in the vertical direction and a worm accommodating portion 22 located on the lower side of the motor accommodating portion 21. The motor accommodating portion 21 and the worm accommodating portion 22 communicate with each other. The case 2 is made of, for example, a resin material. The case 2 may be formed of a metal material or the like. Further, the worm accommodating portion 22 may be provided on the upper side in the vertical direction, and the motor accommodating portion 21 may be provided on the lower side in the vertical direction.

(motor)
The motor 3 is housed in the motor housing portion 21 of the case 2. The motor 3 is fixed to the case 2. The motor 3 has a motor main body 31 and a rotating shaft 32 that rotates around an axis C parallel to the axis O (see FIG. 1). The rotating shaft 32 projects from the motor main body 31 toward the worm accommodating portion 22 side. The rotating shaft 32 is formed in a columnar shape centered on the axis C. When the motor body 31 is driven, the rotating shaft 32 rotates around the axis C. In the following description, unless otherwise specified, the direction along the axis C of the rotating shaft 32 is referred to as the axial direction, the direction orthogonal to the axis C is referred to as the radial direction, and the direction around the axis C is referred to as the circumferential direction. ..
FIG. 4 is a side view of the motor 3 according to the first embodiment.
As shown in FIGS. 3 and 4, a contact portion 34 is provided at an end portion of the rotating shaft 32 opposite to the motor main body 31. The contact portion 34 has a flat surface portion parallel to a plane orthogonal to the radial direction, which is formed by cutting out a part of the rotation shaft 32. In this embodiment, a pair of contact portions 34 are provided. The pair of abutting portions 34, 34 are formed so as to be axisymmetric with respect to the axis C and the plane portions are parallel to each other.

(Cylinder)
Returning to FIG. 3, a tubular body 5 is attached to the inner peripheral portion of the worm 4. The tubular body 5 is arranged coaxially with the axis C. The tubular body 5 is formed of, for example, a metal material, a resin material, or the like. The axial length of the tubular body 5 is shorter than the axial length of the rotating shaft 32. With the tubular body 5 fixed to the rotating shaft 32, the contact portion 34 projects from the tubular body 5 to the opposite side of the motor body 31.

(Warm)
A worm 4 is attached to the outer peripheral portion of the tubular body 5. The worm 4 is made of a resin material. The worm 4 is formed of a member separate from the tubular body 5. The worm 4 is housed in the worm housing portion 22 of the case 2. The worm 4 is formed in a tubular shape coaxial with the axis C. Specifically, the worm 4 includes a tubular main body 41 having one end closed, a worm 42 provided on the outer peripheral portion of the main body 41, and an insertion portion 43 provided on the inner peripheral portion of the main body 41. Have.

The main body 41 is formed in a tubular shape that is coaxial with the axis C and has a lower end 41a on the opposite side of the motor 3 closed. The lower end portion 41a of the main body portion 41 is rotatably supported with respect to the case 2.
The worm portion 42 is provided on the outer peripheral portion of the main body portion 41. The worm portion 42 spirally protrudes from the outer peripheral portion of the main body portion 41. A worm wheel 16 meshes with the worm portion 42.
The insertion portion 43 is a hole recessed from the upper end portion 41b of the main body portion 41 toward the lower end portion 41a. The insertion portion 43 is provided coaxially with the axis C. The insertion portion 43 is formed to have a circular cross section when viewed from the axial direction. A tubular body 5 is inserted into the insertion portion 43. Specifically, after the tubular body 5 is press-fitted into the inner peripheral portion of the insertion portion 43, the rotating shaft 32 is inserted into the inner peripheral portion of the tubular body 5, so that the motor 3 is inserted into the insertion portion 43 via the tubular body 5. The rotating shaft 32 is inserted. In other words, the tubular body 5 is arranged between the rotating shaft 32 and the worm 4. The insertion portion 43 is provided via a tubular body insertion portion 48 provided on the motor 3 side, a step portion 44 provided at an end portion of the tubular body insertion portion 48 opposite to the motor 3, and a tubular body portion 44. It has a reduced diameter portion 45 that communicates with the insertion portion 48.
The step portion 44 is provided on the lower end portion 41a side of the end portion on the side opposite to the motor 3 of the tubular body 5. The step portion 44 is provided so as to be axially separated from the end portion of the tubular body 5.
The inner diameter of the reduced diameter portion 45 is smaller than the inner diameter of the tubular body insertion portion 48. The reduced diameter portion 45 is formed coaxially with the tubular body insertion portion 48. The tip of the rotating shaft 32 is inserted into the reduced diameter portion 45.

FIG. 5 is a perspective view of the worm 4 according to the first embodiment as viewed from the motor 3 side.
The diameter-reduced portion 45 has a pair of transmission portions 46 protruding inward in the radial direction from the inner peripheral portion of the diameter-reduced portion 45, and a bottom portion 47 provided on the side opposite to the tubular body insertion portion 48.
The transmission portion 46 is formed in a triangular shape having an apex angle inward in the radial direction when viewed from the axial direction. The transmission portion 46 is connected to the inner peripheral surface and the bottom portion 47 of the reduced diameter portion 45, respectively. The transmission portion 46 is in contact with the contact portion 34 provided at the tip end portion of the rotating shaft 32 (see FIG. 3) in the circumferential direction. As a result, when the motor 3 is driven, the rotation of the rotating shaft 32 is transmitted to the worm.

(Operation of power transmission device and door mirror device)
Next, the operations of the power transmission device 1 and the door mirror device 10 described above will be described with reference to FIGS. 1 and 2.
When the door mirror main body 12 is electrically operated between the normally used position and the storage position stored when parking or the like, first, the motor 3 is rotationally driven by an operation on the driver's seat side. Then, the rotating shaft 32, the tubular body 5, and the worm 4 rotate integrally. As a result, the worm 4 connected to the rotating shaft 32 of the motor 3 rotates via the tubular body, and the rotation is transmitted to the clutch gear 14 via the worm wheel 16 and the worm gear (not shown).
Here, the clutch gear 14 is fixed to the cylindrical member support device 15 that connects the door mirror support portion 11 and the door mirror main body 12. Further, the cylindrical member support device 15 is fixed to the door mirror support portion 11. Therefore, the clutch gear 14 is restricted in rotation by being fixed to the cylindrical member support device 15 and cannot rotate. Instead, the power transmission device 1, the worm wheel 16 and the worm gear are around the cylindrical member support device 15. Revolve around. As a result, the entire door mirror main body 12 rotates with respect to the door mirror support portion 11 with the cylindrical member support device 15 as the rotation axis.

(Action, effect)
Next, the actions and effects of the power transmission device 1 and the door mirror device 10 described above will be described.
According to the power transmission device 1 according to the aspect of the present invention, the rotating shaft 32 of the motor 3 is inserted into the insertion portion 43 of the worm 4, so that the driving force of the motor 3 is transmitted to the external device (worm wheel) via the worm 4. 16 and the worm gear). As a result, the external device can be driven. Here, since the worm 4 is molded of resin, the dimensional accuracy of the insertion portion 43 may decrease due to sink marks, warpage, shrinkage, etc. of the resin during the manufacture of the worm 4. Therefore, when the worm 4 is molded from the resin material, it is necessary to form the inner diameter of the insertion portion 43 to be larger than the outer diameter of the rotating shaft 32. However, if the inner diameter of the insertion portion 43 is large, the clearance between the worm 4 and the rotating shaft 32 increases, and there is a problem that rattling or noise occurs between the motor 3 and the worm 4 when the motor 3 rotates. was there. In response to this problem, according to the power transmission device 1 of the present invention, since the tubular body 5 is arranged between the rotating shaft 32 and the worm 4, the tubular body 5 is inserted into the insertion portion 43. The inner diameter of the insertion portion 43 distorted due to sink marks, warpage, shrinkage, etc. is corrected, and the dimensional accuracy of the insertion portion 43 can be improved. Further, since the inner diameter of the insertion portion 43 is reduced by inserting the tubular body 5, the clearance between the rotating shaft 32 and the worm 4 is smaller than that of the conventional technique in which the rotating shaft 32 is directly inserted into the worm 4. Can be made smaller. As a result, rattling between the motor 3 and the worm 4 can be suppressed, and the generation of sound when the motor 3 rotates can be suppressed.
Further, since the worm 4 has a transmission unit 46, the rotation of the motor 3 can be reliably transmitted to the worm 4 by the transmission unit 46. Therefore, the rattling between the motor 3 and the worm 4 can be further suppressed.
Therefore, by suppressing the rattling between the motor 3 and the worm 4, it is possible to provide the power transmission device 1 that suppresses the generation of sound when the motor 3 rotates.

Since the transmission unit 46 abuts on the contact portion 34 provided at the tip end portion of the rotating shaft 32 in the circumferential direction, the rotation of the motor 3 can be reliably transmitted to the worm 4.

Since the tubular body 5 is formed of a separate member from the worm 4, the tubular body 5 can be arranged in the worm 4 by press-fitting the tubular body 5 into the insertion portion 43 of the worm 4. As a result, the distortion of the insertion portion 43 and the like can be corrected with high accuracy by the tubular body 5. Further, for example, since the tubular body 5 can be formed of a resin material, a metal material, or the like, the degree of freedom in selecting the material of the tubular body 5 can be improved.

According to the door mirror device 10 according to the aspect of the present invention, since the power transmission device 1 is provided in the door mirror main body 12, the door mirror with respect to the door mirror support portion 11 is driven by the motor 3 of the power transmission device 1. The main body 12 can be driven to rotate.
Therefore, by suppressing the rattling between the motor 3 and the worm 4, it is possible to provide the door mirror device 10 having excellent quietness, which includes the power transmission device 1 that suppresses the generation of sound when the motor 3 rotates. ..

(Second Embodiment)
Next, the power transmission device 1 of the second embodiment will be described with reference to FIG. In the power transmission device 1 of the second embodiment, the same and similar members as those of the power transmission device 1 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.
FIG. 6 is a cross-sectional view of the power transmission device 1 according to the second embodiment.
The second embodiment is different from the first embodiment described above in that the tubular body 5 is integrally formed with the worm 4 by insert molding.

In the second embodiment, the tubular body 5 is formed of a metal material such as aluminum, steel, or stainless steel. The tubular body 5 is arranged in the insertion portion 43 in a state of being integrally formed with the worm 4 by insert molding. The inner peripheral surface of the tubular body 5 and the inner peripheral surface of the insertion portion 43 are flush with each other.

According to the power transmission device 1 of the second embodiment, since the tubular body 5 is formed of a metal material, the rigidity of the tubular body 5 is increased as compared with the case where the tubular body 5 is formed of a resin material or the like. be able to. As a result, the dimensions of the insertion portion 43 by inserting the tubular body 5 can be corrected with high accuracy. Therefore, the rattling between the motor 3 and the worm 4 can be further suppressed, and the generation of sound when the motor 3 rotates can be suppressed.
Further, since the tubular body 5 is integrally formed with the worm 4 by insert molding, the worm 4 in which the tubular body 5 is arranged can be easily manufactured. In particular, as compared with the case where the worm 4 and the cylinder 5 are formed separately and then the cylinder 5 is inserted into the insertion portion 43, the press-fitting step at the time of manufacturing becomes unnecessary, and the number of steps can be reduced. Therefore, the manufacturability of the power transmission device 1 can be improved.

Although preferable examples of the present invention have been described above, the present invention is not limited to these examples. Configurations can be added, omitted, replaced, and other modifications without departing from the spirit of the present invention. The present invention is not limited by the above description, but only by the scope of the accompanying claims.
For example, in the above-described embodiment, the end portion of the tubular body 5 opposite to the motor 3 is arranged so as to be separated from the step portion 44, but the present invention is not limited to this. The end portion of the tubular body 5 may come into contact with the step portion 44. Further, the step portion 44 and the diameter reduction portion 45 may not be provided. That is, the transmission portion 46 may be provided in the cylinder insertion portion 48.
Further, when the tubular body 5 is formed of a resin material, it is more preferable to form the tubular body 5 with a resin material having a higher rigidity than the worm 4.

The contact portion 34 of the rotating shaft 32 may be, for example, a convex portion. In this case, it is preferable that the worm 4 is provided with a concave portion with which the convex portion engages.
The cross-sectional shape of the transmission unit 46 when viewed from the axial direction may be formed in a shape other than a triangular shape, such as a rectangular shape or an elliptical shape. The transmission portion 46 may be provided at a distance from the bottom portion 47.
The axis O and the axis C do not have to be parallel.

The power transmission device 1 is configured to be connected to the worm wheel 16 and the worm gear, but may be connected to, for example, a reduction mechanism or a gear.

In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate without departing from the spirit of the present invention, and the above-described embodiments may be combined as appropriate.

1 ... Power transmission device 2 ... Case 3 ... Motor 4 ... Worm 10 ... Door mirror device 12 ... Door mirror body 16 ... Warm wheel (external device)
32 ... Rotating shaft 43 ... Insertion unit 46 ... Transmission unit

Claims (5)

With the case
A motor supported by the case and having a rotating shaft,
A resin worm having an insertion portion into which the rotating shaft is inserted and transmitting the driving force of the motor to an external device.
In a power transmission device equipped with
The worm
A cylinder provided in the insertion portion and arranged between the rotation shaft and the worm, and
A transmission unit to which the rotation of the rotation shaft is transmitted, and
A power transmission device characterized by having. The power transmission device according to claim 1, wherein the transmission unit abuts on the tip end portion of the rotation shaft in the circumferential direction of the rotation shaft. The power transmission device according to claim 1 or 2, wherein the tubular body is formed of a metal material and is arranged in the insertion portion in a state of being integrally formed with the worm by insert molding. The power transmission device according to claim 1 or 2, wherein the tubular body is formed of a member separate from the worm and is arranged in the insertion portion in a state of being press-fitted into the insertion portion. A door mirror device according to any one of claims 1 to 4, wherein the power transmission device is provided on the door mirror main body.

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