JPH01204835A - Retractable door mirror - Google Patents

Abstract

PURPOSE:To make output of a surface wave motor adjustable with a gearing means by installing a driving gear in a drive shaft of the surface wave motor free of sliding motion in the thrust direction, and fitting a driven gear being engaged with this driving gear externally in a support shaft of a mirror housing. CONSTITUTION:A mirror housing 12' is provided with a mirror 14 and rotatably supported by a shaft part 16' of a mirror base 10' being attached to a car body. In this case, a surface wave motor 60 as a driving means is set up in this shaft part 16'. A drive shaft 61 of the surface wave motor 60 is fitted in a worm driving gear 62 free of sliding motion, while a worm driven gear 63 being fitted in this work driving gear 62 is fitted in the shaft part 16' free of rotation. With this constitution, the mirror housing is rotated by the surface wave motor. At this time, reaction in the thrust direction received by the worm driving gear 62 is supported by thrust bearings 64, 65 without being added to the shaft part 16'.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a retractable door mirror whose mirror housing can be rotated between a normal position and a retracted position to provide the driver with optimal rear visibility. Regarding.

[Conventional technology]

This type of retractable door mirror is equipped with an electric motor and a group of reduction gears inside the mirror housing in order to rotate the mirror housing around an axis fixed to the mirror base, but these are heavy. The use of a surface wave motor as a drive source for rotating the mirror housing has been proposed for reasons such as the volume of the mirror housing that accommodates these components becoming large and the degree of freedom in designing the door mirror being restricted. Such a retractable door mirror is disclosed in Japanese Patent Application No. 60-234596 filed by the applicant of the present application.

FIG. 4 shows a retractable door mirror using a surface wave motor as a driving source.

The mirror housing 12 includes a mirror 14 and is rotatably supported around a shaft portion 16 of a mirror base IO to be attached to the vehicle body. Mirror housing 12
A bracket 18 is fixed inside, and a bearing z4 that supports a part of the shaft portion 16 is fixed to the upper part of the bracket 18. A vibrator (stator) and a movable body (rotor) constituting a surface wave motor are disposed coaxially on the shaft portion 16, the vibrator is fixed to a mirror housing, and the movable body is attached to the shaft portion 16 for rotation around the axis. is placed in a state where it is blocked. The vibrator is composed of an elastic ring 32 and a piezoelectric element 34, and the moving body is a rubber slider 38 that comes into contact with the elastic ring 32.
The rotor 36 includes a rotor 36. The contact surface between the elastic ring 32 of the vibrator and the slider 38 of the moving body is pressed by a compression coil spring 42. The compression coil spring 42 is disposed between a seat 44 that is prevented from moving toward the shaft output by a washer 48 and another seat 46 that contacts the surface of the rotor 36, and the compression coil spring 42 is arranged between the slider 38 and the elastic ring 32. It applies a frictional force to the contact surface.

When a high frequency voltage is applied to the piezoelectric element 34, the elastic ring 3
2, a traveling wave is formed due to bending vibration, and the rotor 36 attempts to rotate in a direction opposite to the direction of the traveling wave. Since the rotor 36 is prevented from rotating around the axis, the elastic link 32 is rotated around the axis by the reaction force. That is, the mirror housing 12 is rotated. Such surface wave motors are lightweight and compact, and have the characteristics of being able to obtain large torque at low rotation speeds. 56 is a switch for detecting the rotation angle of the mirror housing 12.

[Problem to be solved by the invention]

However, in the conventional door mirrors as mentioned above,
#16 rotatably supports the mirror housing 12
doubles as the drive shaft of the two-surface wave motor. For this reason, the output of one surface wave motor cannot be increased or decelerated by gear means.

In some cases, it may be necessary to construct both of the above-mentioned shafts (the mirror housing support shaft and the surface wave motor drive shaft) separately, and to interpose gear means between the two shafts.

If a spur gear is used as the above-mentioned gear means, there will be no separate problem, but if a worm gear or a helical gear is used, a thrust force will be applied to the drive shaft (output shaft) of the surface wave motor.

When a surface wave motor receives thrust on its drive shaft (output shaft), its operation is hindered.

The present invention has been made in view of the above-mentioned circumstances, and what happens when the drive shaft (output shaft) of the surface wave motor and the obstructing shaft of the mirror housing are configured separately and a gear transmission structure is adopted. An object of the present invention is to provide a retractable door mirror driven by a single surface wave motor, which has a structure in which no thrust is applied to the drive shaft (output shaft) of the surface wave motor even when a gear is used.

[Means to solve the problem]

The retractable door mirror according to the present invention was created to achieve the above object. join to.

(n) A receiving gear that meshes with the original gear is externally fitted onto the mirror housing support shaft, and the receiving gear and the mirror housing are connected by some means (for example, by a friction clutch).

[For production]

According to the above means, since the base gear can slide freely in the thrust direction with respect to the surface wave motor drive shaft (output shaft), the thrust force that the base gear receives due to the reaction force of the tooth surface is applied to the surface wave motor drive shaft ( (output shaft). The above thrust force is supported by a thrust receiver provided separately from the drive shaft.

〔Example〕

FIG. 2 is a sectional view of a retractable door mirror according to an embodiment of the present invention, and corresponds to FIG. 4 in the conventional example.

In order to facilitate comparison between the two figures, similar parts that correspond to each other are shown with the same drawing reference number and a dash.

Reference numeral 60 indicated by a phantom line is a surface wave motor, the contents and configuration of which are the same as the surface wave motor described with reference to FIG.

61 is a drive shaft that outputs the rotational force generated by the surface wave motor 60, and is D-cut. The worm gear 62 has a D-cut hole, and is fitted into the drive shaft so as to be slidable in the axial direction.

A worm receiving gear 63 that meshes with the worm source gear is rotatably fitted to the mirror housing support shaft 16'.

When the surface wave motor 60 rotates, the worm gear 62 is rotated, and the worm gear 62 attempts to rotate the worm receiving gear 63.

Since the worm receiving gear 63 is restrained from rotating relative to the mirror housing support shaft by frictional force, the mirror housing 12' equipped with one surface wave motor 60 is rotated by the reaction force. At this time, the worm gear 62 receives a thrust force in a direction perpendicular to the plane of the paper.

FIG. 1 shows a cross section taken along line 1-1 in FIG.

The worm gear 62 is fitted onto the D-cut drive shaft 61 so as to be slidable in the thrust direction (up and down in the figure). The illustrated upward thrust of the worm gear 62 is supported by a thrust bearing 64, and the illustrated downward thrust is supported by a thrust bearing 65.

According to this structure, the reaction force in the thrust direction that the worm gear 62 receives is not applied to the drive shaft 61 but is supported by the thrust bearings 64 and 65, so that the surface wave motor 60 is operated by the thrust force. There is no risk of this being interfered with.

Figure 3 shows an embodiment different from the above. The difference from the embodiment shown in FIG. 1 is that a single steel ball 66 is used instead of the thrust bearing 65 to receive the downward thrust force in the figure. This example also provides the same effects as the previous example.

〔Effect of the invention〕

According to the retractable door mirror of the present invention, the rotational output of one surface wave motor can be increased, decelerated, and transmitted through a gear mechanism, and the drive shaft of the surface wave motor can be transmitted using any type of gear. Thrust force cannot be applied to (output shaft).

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing one embodiment of the retractable door mirror of the present invention, with main parts shown in cross section. Second
The figure is a partially cutaway front view of the above embodiment. FIG. 3 is a partial plan view of an embodiment different from the above. FIG. 4 is a partially cutaway front view of the conventional example. DESCRIPTION OF SYMBOLS 10...Mirror base, 12.12'...Mirror housing, 16.16'...Mirror housing support shaft, 18...Bracket, 24...Bearing, 32...
Elastic ring, 34... Piezoelectric element, 36... Rotor, 38... Slider, 42... Coil spring,
60... Surface wave motor, 61... Drive shaft (output shaft)
, 62... Worm original gear, 64.65... Thrust bearing, 66... Steel ball.

Claims (1)

[Claims] 1. (a) A mirror housing is rotatably supported by a shaft fixed to a mirror base to be attached to the vehicle body, and the mirror housing is moved by a driving means disposed within the mirror housing. A retractable door mirror configured to rotate around the support shaft between a normal position and a retracted position, (b) the drive means is disposed on a drive shaft separate from the support shaft; A surface wave motor comprising an annular vibrator formed by incorporating a piezoelectric element into an elastic body, and an annular rotor disposed coaxially with the drive shaft and having a surface in contact with one end surface of the elastic body. The contact surface between the elastic body and the rotor is in contact with each other so as to convert a traveling wave, which is synthesized by a transverse wave and a longitudinal wave excited on the surface of the elastic body, into rotation of the rotor in one direction. one of the vibrator or the rotor is fixed to the mirror housing, and the other is disposed so as to be movable in the axial direction while being prevented from rotating around the axis; (c) on the drive shaft; On the other hand, the original gear is externally fitted by locking the sliding movement in the axial direction and the rotation around the axis, and (d) the receiving gear fitted to the support shaft is A retractable door mirror, comprising: (e) a means for supporting the thrust of the receiving gear;