JPH0541077Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to a drive device for an electric rearview mirror, and in particular, the actuation rod and the operating shaft provided on the rotational center line of the worm wheel have a ball portion. This invention relates to a driving device for an electric rearview mirror that can be easily tilted around the center and can have a large tilting angle.

[Prior Art] An example of a drive device that automatically adjusts the reflection angle of a back mirror by a motor is shown in FIGS. The structure is such that swing motion can be performed centering on the . That is, the actuator housing 1 is constructed by fitting a front housing 1a and a rear housing 1b so as to be divided into two parts in the front and rear, and includes a motor (not shown), a worm 2 attached to the output shaft of the motor, and a worm 2 attached to the output shaft of the motor. It houses a worm wheel 3 that meshes with the worm 2.

As can be seen from Figure 6, the worm wheel 3
The worm wheel 3 is fitted at both ends into annular support parts 8a and 8b provided on the front housing 1a and the rear housing 1b, respectively, so that the center line of rotation thereof is perpendicular to the mirror surface.
A pivot screw 4 is inserted into the center of the wheel and is engaged to rotate integrally with the wheel. The pivot screw 4 has a hemispherical recess 5 formed in the center of the back surface of its bottom plate 4A, and the recess 5
By fitting the hemispherical protrusion 6 provided on the front housing 1a side into the pivot screw 4
It is supported so that it can tilt in an arc as shown by arrow B around the pivot position.

Also, the threaded portion 4B on the circumferential surface of the pivot screw 4
An adjuster nut 7 is engaged with the adjuster nut 7, and the movable pivot P is attached to the tip of the adjuster nut 7.
is formed and connected to the back surface of the mirror holder, and by rotating the worm wheel 3 and pivot screw 4 by a motor, the adjusting nut 7 is moved back and forth in the front and back direction of the mirror surface to adjust the inclination angle of the mirror. ing.

[Problems to be solved by the invention] This type of drive device needs to be assembled so as not to cause specular vibration (chatter), but there may be dimensional variations (tolerances) of the molded parts or assembly problems. There is a drawback that large play is likely to occur in the thrust direction of the pivot screw 4 due to inevitable misalignment. That is, in the conventional drive device, for example, as shown in FIG. 6, the backlash in the thrust direction is mainly caused between the rear housing 1b and the worm wheel 3, the front housing 1a and the pivot screw 4, and the worm wheel 3 and the pivot. This is thought to occur because there is a gap between the combination with the screw 4, and tuning the gap requires a considerable amount of man-hours (labor). Moreover, in order to enable the arcuate swinging motion (arrow B) of the adjuster nut 7, the lower fitting inner surface of the worm wheel 3 and the pivot screw 4 has a spherical surface 3.
M, and is fitted so that it can tilt with respect to this spherical surface using the protrusion 6 of the pivot screw 4 as a fulcrum, but the pivot screw 4 that forms a fitting surface with the spherical surface Since the contact position with the curved surface 4N is close to the diameter line S of the spherical surface as shown in the same enlarged view, a slight deviation in the dimensions of the component causes a large play in the thrust direction.
This was the main reason why tuning was difficult.

In order to reduce the above-mentioned tuning man-hours and to reduce backlash in the thrust direction, the inventors of the present invention first integrated a conical bottom plate into the lower part of the worm wheel 30 as proposed in Utility Application No. 166701/1983. At the same time, we proposed a mirror drive device in which a pivot screw 40 is provided integrally with the wheel on the center line of the bottom plate, and the pawl portion 41 of an adjuster nut is engaged with the thread groove of the screw (Fig. 7). reference). But the above is
The engagement load of the claw portion 41 of the adjuster nut with respect to the thread groove of the screw 40 tends to vary. In other words, when attempting to tilt the mirror holder to a large extent, the claw portion 41 of the adjuster nut is strongly pressed against the thread groove of the screw 40, so the engagement load of the claw portion fluctuates, increasing the frictional resistance against the screw 40, and the worm wheel Movement becomes worse. Therefore, the reflection angle adjustment speed of the back mirror becomes slow.

Here, the present invention aims to improve the problems of the above-mentioned previous designs. In other words, it reduces the number of man-hours for tuning, reduces backlash in the thrust direction, and prevents the engagement load of the adjuster nut's pawl with the screw's thread groove from changing when the mirror holder is tilted significantly. It was made into
In particular, it is an object of the present invention to provide a driving device for an electric rear view mirror in which an operating rod and an operating shaft can be easily tilted about a spherical portion provided on the center line of rotation of a worm wheel.

[Means for Solving the Problems] In order to achieve the above object, the present invention supports a mirror holder to which a mirror is attached so as to be tiltable with respect to an actuator housing, and a mirror holder that is housed in the actuator housing. An operating rod having a spherical portion at its tip that fits into a spherical catch located at a position distant from the center of rotation of the mirror holder is driven forward and backward in the front and back direction of the mirror surface through a terminal gear element of the electric reduction gear mechanism. In the device for adjusting the reflection angle of the mirror, a conical bottom plate is integrally formed at the lower part of the terminal gear element, and several window holes are formed at predetermined intervals on the bottom plate surface to make it deformable. , comprising an operating shaft having a spherical portion at its rear end on the center line of rotation of the bottom plate, and a concave spherical socket formed integrally with the terminal gear element and preventing rotation of the spherical portion, One of them is integrally provided with a threaded rod with a thread formed on its circumferential surface, and the other is integrally provided with a flexible claw that engages with the thread, so that when the terminal gear element rotates, the operating rod is operated via the operating shaft. It is characterized by being driven forward and backward in the front and rear directions of the mirror surface.

[Example] Hereinafter, an example of the drive device of the present invention will be specifically described based on the drawings. Figure 1 is an enlarged cross-sectional view schematically showing the present drive device incorporating a reduction gear mechanism with a worm wheel as the end gear element, and Figure 2 is an operation diagram with the end gear element of the reduction gear mechanism and a ball section at the rear end. FIG. 3 is an enlarged sectional view showing the engagement relationship with the shaft. Moreover, FIG. 3 is a sectional view of the main part showing a modification of the present invention.

In the figure, 10 is an actuator housing. This housing is front housing 1
It is constructed by fitting two parts into a rear housing 0a and a rear housing 10b.

At approximately the center of the front surface of the actuator housing 10, there is a mirror holder 1 having a reflecting mirror (not shown).
There is a center pivot 30 that is the center of rotation of the mirror holder, and a spherical portion 13 that fits into a spherical seat 15 provided on the back surface of the mirror holder is located at a predetermined distance from the center of rotation of the mirror holder. An operating rod 12 for adjusting the angle is provided in a protruding manner (FIG. 1).

Now, the mirror holder with the mirror attached is supported so as to be tiltable relative to the actuator housing.
Further, an electric reduction gear mechanism (not shown) is incorporated in the actuator housing to move the operating rod 12 forward and backward. Reference numeral 16 is a terminal gear element (worm wheel in the illustrated example) of this electric reduction gear mechanism, and this worm wheel 16 is provided in the front and rear housings 11a and 11b so that its central axis is perpendicular to the mirror surface. It is rotatably supported by annular support parts 17a and 17b.

A thin conical bottom plate 19 is integrally formed in the lower part of the worm wheel 16, and several fan-shaped window holes 21 are formed at intervals of 120 degrees on the bottom plate surface, so that the worm wheel 16 can be deformed. Furthermore, the bottom plate 1
The operating shaft 1 has a ball portion 22 at the rear end on the center line of the shaft 9.
8, and a concave spherical socket 20 which is integrally formed with the bottom plate 19 of the worm wheel 16, and into which the spherical portion 22 is fitted and prevented from rotating. Incidentally, as a means for preventing rotation, it is preferable to provide a small protrusion 23 on the spherical side and a rotation preventing groove 24 in which the small protrusion 23 engages on the concave spherical socket side, as shown in the exploded view of FIG.

Reference numeral 25 is a hemispherical recess formed in the center of the lower surface of the bottom plate 19, and 26 is a fulcrum of the worm wheel 16 that fits into the recess.

The operating shaft 18 is formed as a hollow or solid rod, and a thread 18B is formed on the outer circumferential surface of the rod. On the other hand, a flexible pawl 12B constituting a nut that engages with the screw 18B is integrally formed at the other end of the operating rod 12 provided on the back surface of the mirror holder. In this way, when the worm wheel 16 rotates, the operating rod 12 is driven back and forth in the front and rear directions of the mirror surface via the operating shaft 18, thereby adjusting the reflection angle of the rear mirror.

As shown in FIG. 3, the operating rod 12 is configured as a threaded rod with a thread formed on its circumferential surface, and the operating shaft 18 is integrally provided with flexible claws constituting a nut that engages with the thread. There is no problem even if the configuration is set.

Worm wheel 16 and concave spherical socket 20
It is possible to integrally mold the worm wheel 16A with an engineering plastic such as polyacetal or polycarbonate, but as shown in FIG. It is also possible to provide a holding member 20B that is caulked 25 on the worm wheel side, bring the spherical part 22 into contact with the concave spherical part 20A, and then fix the periphery of the spherical part 22 with the holding member 20B. It is.

[Effects of the invention] According to the invention configured as described above, when the terminal gear element rotates, the operating rod is driven forward and backward in the front and rear directions of the mirror surface via the operating shaft, so that the mirror holder with the mirror attached is placed in the center. Swing movement is possible around the pivot, and the tilt angle of the rearview mirror can be easily adjusted.

In particular, the operating shaft includes an operating shaft having a spherical portion at its rear end on the center line of rotation of the bottom plate of the terminal gear element, and a concave spherical socket formed integrally with the terminal gear element and preventing rotation of the spherical portion; Alternatively, one of the operating shafts is integrally provided with a screw rod with a thread formed on its circumferential surface, and the other is integrally provided with a flexible claw that engages with the screw, so that it is installed on the rotation center line of the terminal gear element. Only the operating rod and the operating shaft can be easily tilted around the spherical part, and the angle of inclination can be made much larger than that of the conventional type. As a result,
When trying to tilt the mirror holder greatly, it is possible to avoid large fluctuations in the engagement load of the claws with the thread grooves, and the movement of the gear element becomes slow, slowing down the reflection angle adjustment speed of the back mirror. Demerits can be improved.

In addition, in the present invention, a conical bottom plate is integrally formed at the bottom of the terminal gear element, and several window holes are formed at predetermined intervals on the bottom plate surface so that it can be deformed. Vibrations in a direction perpendicular to the axis of the shaft are absorbed by the conical bottom plate having the window hole, thereby preventing noise such as pulsation and chatter caused by the vibrations.

[Brief explanation of the drawing]

Figure 1 is an enlarged cross-sectional view schematically showing the present drive device incorporating a reduction gear mechanism with a worm wheel as the end gear element, and Figure 2 is an operation diagram with the end gear element of the reduction gear mechanism and a ball section at the rear end. FIG. 3 is an enlarged sectional view showing the engagement relationship with the shaft. Also the third
5 and 4 are sectional views of essential parts showing a modification of the present invention, FIG. 5 is a schematic side view of a rearview mirror drive device, and FIGS. 6 and 7 are schematic sectional views of a conventional drive device. . 10... Actuator housing, 12...
Operating rod, 12B... Flexible claw, 13... Ball portion, 14
...Mirror holder, 15...Spherical catch, 16...
...Terminal gear element (worm wheel), 1
8... Operating shaft, 18B... Screw, 20A... Concave ball portion, 20B... Holding member.

Claims (1)

[Claims for Utility Model Registration] 1. A mirror holder 14 to which a mirror is attached is supported so as to be tiltable relative to the actuator housing 10, and the actuator housing 10
said mirror holder 14 via a terminal gear element 16 of an electric reduction gear mechanism housed within.
The spherical catch 15 is located away from the center of rotation of
An operating rod 12 with a ball portion 13 at its tip that fits into the
In this device, a conical bottom plate 19 is integrally formed at the lower part of the terminal gear element 16, and several pieces are arranged at predetermined intervals on the bottom plate surface. A window hole 21 is formed so that the operation shaft 18 can be deformed, and the operating shaft 18 is provided with a ball part 22 at the rear end on the center line of the bottom plate 19. A concave spherical socket 20 that prevents rotation, one of the operating rod 12 or the operating shaft 18 has a threaded rod with a thread 18B formed on the circumferential surface, and the other has a flexible claw that engages with the thread. 12B, respectively, and when the terminal gear element 16 rotates, the operating rod 12 is driven forward and backward in the front and back direction of the mirror surface via the operating shaft 18. 2. The terminal gear element 16 includes a concave spherical portion 20A that constitutes a part of the concave spherical socket, and a holding member 20B that is disposed around the outer periphery of the spherical portion 22 that abuts the concave spherical portion and is caulked to the terminal gear element.
A drive device for an electric rear view mirror according to claim 1, which is provided with the following. 3. The electric rear view mirror drive device according to claim 1 or 2, wherein the terminal gear element 16 is a worm wheel.