JP2633388B2 - Drive device for retractable door mirror - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a drive device for a retractable door mirror of an automobile, that is, a device for rotating a visor holding a mirror body with respect to a stay fixed to a door to set the visor in a retracted position and an upright position.

2. Description of the Related Art Conventionally, in a retractable door mirror, generally, a shaft extending in a substantially vertical direction is fixed to a stay, a cylindrical bearing portion is formed in a visor, and this bearing portion is fitted to a stay shaft. The visor can be rotated with respect to the stay. As the driving device, an electromagnetic motor is generally mounted on a visor side, and its rotation is transmitted to a stay shaft via a speed reduction mechanism. In the above configuration, the stay axis is fixed,
By operating the electromagnetic motor, the motor itself revolves around the axis of the stay, and accordingly, the visor rotates to set the storage position and the standing position.
Also, the reduction mechanism is provided because the output shaft of the electromagnetic motor rotates at a high speed and the obtained torque is small, and in general, large and small spur gears that mesh with each other are connected to the output shaft of the motor and the stay. It is used several times between the shaft.

[Problems to be solved by the invention]

However, in the case where the speed reduction mechanism is configured in this manner, there is a problem that noise is generated from the spur gear that meshes immediately after the output shaft of the motor because the spur gear rotates at high speed. In addition, there is a problem that a large space is required in the visor in order to use the spur gears in a stacked state, and the number of parts is increased to increase the cost. Therefore, a technical problem to be solved by the present invention is to make it possible to configure a driving device for a retractable door mirror in a small space with a small number of components, and at the same time to prevent the generation of noise.

[Means for Solving the Problems and Functions / Effects]

The drive device for a retractable door mirror according to the present invention is configured as follows in order to solve the above technical problem. That is, the reduction mechanism that connects the motor and the vertical shaft
The motor includes a first reduction gear on the motor side and a second reduction gear on the vertical axis side. The first reduction gear comprises a worm and a worm wheel, and the second reduction gear comprises a pair of spur gears. I have. The first reduction gear includes a first worm connected to an output shaft of the motor, a first worm wheel meshing with the first worm, and a second worm formed coaxially with the first worm wheel. And a second worm wheel that meshes with the second worm. The torsional angles of the first worm wheel and the second worm are set in directions that cancel out the respective thrust forces. In this configuration, the rotation of the motor is first transmitted to the vertical shaft via the spur gears constituting the second reduction stage after being greatly reduced by the engagement of the worm and the worm wheel constituting the first reduction stage. Although the output shaft of the motor rotates at high speed, almost no sound is generated when the worm and the worm wheel mesh with each other, and the meshing of the spur gear is performed at a low speed after being sufficiently reduced in the first reduction gear. There is almost no sound in the part. Therefore, the visor can be driven quietly. Further, if a worm and a worm wheel are used, a large reduction ratio can be obtained by one engagement, and the number of parts can be reduced, so that the drive device can be made compact. Further, by limiting the twist angle between the first worm wheel and the second worm, the first worm wheel and the second
Since a large thrust load is not applied to the bearing of the worm, the bearing can be designed to be compact. Therefore, the size of the entire driving device can be further reduced.

【Example】

Hereinafter, the driving device of the retractable door mirror according to the embodiment of the present invention shown in FIGS. 1 to 6 will be described in detail. FIG. 1 is an exploded perspective view of the driving device, and FIG. 2 is an enlarged sectional view of a main part. In the figure, 1 is a stand fixed to a stay attached to a vehicle body (door), and 2 is a bracket fixed to a visor holding a mirror body.
The stand 1 has a base 1a that extends in a substantially vertical direction.
The bracket 2 has a cylindrical bearing 2a formed on the base 2b. The vertical shaft 1a and the bearing portion 2a are fitted in a state where a moderation mechanism including the spring 3, the ball 4, and the detent plate 5 is interposed between the respective base portions 1b and 2b. A spring 6 is mounted around the bearing 2a. A first spur gear 7 having protrusions 7a formed at three circumferential positions and a clutch 8 having a recess 8a formed at a position corresponding to the protrusion 7a are mounted on the spring 6. Further, a stop ring 9 is attached to a portion of the shaft 1a protruding above the bearing portion 2a so as to determine the upper limits of the positions of the first spur gear 7 and the clutch 8 and to flex the spring 6. Have been. In the clutch 8, the shaft 1a is prevented from rotating by means such as a key. A hollow case 10 is mounted on the base 2b of the bracket 2, and a motor bracket 12 on which a motor 11 is mounted is mounted thereon. The motor 11 and the vertical shaft 1a are connected by a speed reduction mechanism formed in the hollow portion of the case 10. The motor bracket 12 is provided with a detection switch 19 for detecting a relative position with respect to the shaft 1a and stopping the motor 11 at a predetermined position. The speed reduction mechanism is configured as follows from a worm and worm wheel stage as a first reduction stage and a spur gear stage as a second reduction stage. First, the first worm 13 is directly connected to the output shaft of the motor 11, and the tip is supported by the case 10. A first worm wheel 14 meshing with the first worm 13 and a second worm 15 are formed coaxially and integrally with each other.
, And is supported by bearings 16 held therein. further,
The second worm wheel 17 meshing with the second worm 15
And a second spur gear 18 integrally formed coaxially, and the upper end thereof is rotatably held by the case 10 and the lower end thereof is rotatably held by the base portion 2b of the bracket 2. The second spur gear 18 meshes with the first spur gear. Also,
The case 10 in which these gears are stored is sealed with a lid 20. The torsional angles of the first worm wheel 14 and the second worm 15 are set in directions in which the respective thrust forces cancel each other. The twist angle is the first worm 13
For example, in the above-described example, the direction is set in a direction indicated by a thin line in FIG. When the positional relationship is changed as shown in FIGS. 4 to 6, the twist angle may be set as shown by a thin line in each figure. In addition,
In these figures, white arrows indicate the rotation direction of each worm, and arrows attached to the outside of the first worm wheel 14 and the second worm 15 indicate the thrust force generated respectively. When the motor 11 rotates in the reverse direction, the thrust forces are also directed in opposite directions, and these always act as loads in opposite directions. In this configuration, even when the motor 11 is rotated and its driving force is transmitted to the first spur gear 7, the first spur gear 7 does not rotate because the clutch 8 is prevented from rotating around the shaft 1a. The bracket 2 holding up to the second spur gear 18 rotates around the shaft 1a against the detent mechanism including the spring 3, the ball 4, and the detent plate 5. Then, the rotation of the motor 11 is stopped at a predetermined position by the action of the detection switch 19, and the visor is set to the storage position and the upright position. In this drive device, the rotation of the motor is firstly reduced between the worm and the worm wheel, which is the first speed reduction stage, so that almost no noise is generated during that period. Further, since the reduction ratio can be increased by using a worm as compared with a spur gear, the number of parts can be reduced and the apparatus can be made compact as a whole. Further, since the torsional angles of the first worm wheel 14 and the second worm 15 are set so as to cancel the thrust forces generated respectively, the bearing portions can be configured to be small.

[Brief description of the drawings]

1 to 6 show a drive device for a retractable door mirror according to one embodiment of the present invention, FIG. 1 is an exploded perspective view, FIG. 2 is an enlarged sectional view of a main part, and FIG. 4 to 6 are perspective views of a speed reduction mechanism according to a modification. 1 ... Stand, 1a ... Vertical axis, 1b ... Base part, 2 ...
... Bracket, 2a ... Bearing part, 2b ... Base part, 3 ...
... Spring, 4 ... Ball, 5 ... Detent plate, 6 ... Spring, 7 ... First spur gear, 7a ... Protrusion, 8 ... Clutch, 8a ... Recess, 9 ... Stop ring, 10 ... case, 11 ... motor, 12 ... motor bracket, 13 ... first worm, 14 ... first worm wheel, 15 ... second worm, 16 ... bearing, 17 ... second worm wheel, 18 ... second spur gear, 19 ... detection switch, 20 ... lid

Claims (1)

(57) [Claims] 1. A substantially vertical shaft (1a) is fixed to a stay fixed to a door of a vehicle body in order to set a storage position and an upright position by rotating a visor holding a mirror body with respect to a stay fixed to a door of the vehicle body. And the motor (1
1) is fixed, and the rotation of the motor (11) is
a) In a drive device for a retractable door mirror provided with a reduction mechanism (7, 13, 14, 15, 17, 18) for transmitting to the above (a), the reduction mechanism (7, 13, 14, 15, 17, 17, 18) Motor (1
1) 1st side reduction gear (13,14,15,17) and vertical axis (1a)
And the first reduction gear (13, 14, 15, 17) includes a worm (13, 15) and a worm wheel (14, 17). The second
The reduction gears (7, 18) are constituted by a pair of spur gears, and the first reduction gears (13, 14, 15, 17) are connected to a first worm (13) connected to an output shaft of a motor (11). A first worm wheel (14) meshing with the first worm (13); and a second worm wheel (14) formed coaxially with the first worm wheel (14).
A worm (15), and a second worm wheel (17) meshing with the second worm (15), and the torsional angles of the first worm wheel (14) and the second worm (15) are respectively generated. A drive device for a retractable door mirror, wherein the drive device is set in a direction to cancel the thrust force.