JPH0454031Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention allows the mirror housing to be rotated relative to the mirror base between a normal position and a retracted position that provides the driver with optimal rearward visibility. Regarding retractable door mirrors.

[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 and It has been proposed to use a surface wave motor as a drive source for rotating the mirror housing because the volume of the mirror housing that accommodates these becomes large and the degree of freedom in designing the door mirror is restricted. Japanese Patent Application No. 60-234596 (Japanese Unexamined Patent Publication No. 62-234) filed by the applicant of this application
-94444) discloses such a retractable door mirror.

FIG. 5 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 10 to be attached to the vehicle body.
A bracket 18 is fixed within the mirror housing 12, and a bearing 24 that supports a portion of the shaft portion 16 is fixed to the upper part of the bracket 18. Shaft 1
A vibrator (stator) and a movable body (rotor) constituting a surface wave motor are coaxially disposed in 6, the vibrator is fixed to the mirror housing 12 via a substrate 28, and the movable body is fixed to the shaft part 16. It is arranged so that rotation around the axis is prevented. The vibrator is composed of an elastic ring 32 and a piezoelectric element 34, and the movable body is composed of a rotor 36 including a rubber slider 38 that comes into contact with the elastic ring 32. Elastic ring 32 of the vibrator and slider 3 of the moving body
The contact surface with 8 is pressed by a compression coil spring 42. The compression coil spring 42 is disposed between a catch 44 that is prevented from moving upwardly on the shaft portion 16 by a washer 48 and another catch 46 that contacts the surface of the rotor 36, and is arranged between a catch 44 that is prevented from moving upwardly by a washer 48, and another catch 46 that contacts the surface of the rotor 36. Frictional force is applied to the contact surface between 38 and the elastic ring 32.

When a high frequency voltage is applied to the piezoelectric element 34, a traveling wave is formed in the elastic ring 32 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 ring 32 is rotated around the axis by the reaction force. That is, the mirror housing 12 is designed to be rotated. Such a surface wave motor is lightweight and compact, and has the characteristics of being able to obtain large torque at low speed rotation, and rotates the mirror housing 12 from the normal position to the retracted position, or from the retracted position to the normal position. When doing so, an appropriate frictional force is required on the contact surface between the elastic ring 32 and the slider 38.

[Problem that the invention attempts to solve]

However, in the conventional door mirror as described above, when the mirror housing 12 is not rotating, the compression coil spring 42 is used to cause the elastic ring 32 of the vibrator and the slider 38 of the moving body to act as a friction transmission clutch. The elastic ring 32 has been given a considerable elastic force.
There is a problem in that a frictional force greater than the above-mentioned appropriate frictional force is generated on the contact surface between the mirror housing and the slider 38, and the rotation of the mirror housing may not be carried out smoothly.

The purpose of the present invention is to provide an improved retractable door mirror using a surface wave motor, which eliminates the problems of the conventional retractable door mirror described above, that is, a retractable door mirror whose mirror housing can be rotated smoothly. There is a particular thing.

[Means for solving problems]

In the present invention, in the normal state, a predetermined frictional force is obtained in the connected state, and when the surface wave motor is energized in synchronization with the surface wave motor, it is in the disconnected state and the surface wave motor is activated under the spring force of the spring member. The present invention is characterized in that an electromagnetic friction transmission clutch is disposed between the mirror base and the mirror housing to release the above-mentioned frictional force so that the mirror housing can be rotated by driving.

[Effect]

In the present invention, with the above configuration, when the mirror housing is in the normal position or the retracted position, the electromagnetic friction transmission clutch is in the engaged state, so that a predetermined frictional force can be obtained. As a result, when a large impact is applied to the mirror housing from the outside, the mirror housing rotates slowly.

In addition, when rotating the mirror housing from the normal position to the retracted position or from the retracted position to the normal position by remote control, the electromagnetic friction transmission clutch is activated by energizing the surface wave motor and the electromagnetic friction transmission clutch. and becomes disconnected. As a result, only the minimum necessary spring force of the spring member is applied to the contact surface between the surface wave motor's vibrator and the moving object, minimizing the influence of the spring's pressing force on the rotation of the surface wave motor. It can be held down.

〔Example〕

Hereinafter, one embodiment of the retractable door mirror of the present invention will be described in detail with reference to FIGS. 1 to 4.

In FIG. 1, reference numeral 10 indicates a base to be fixed to the vehicle body, and a mirror housing 12 provided with a mirror 14 is rotatably supported by a shaft portion 16 fixed to the base 10. Inside the mirror housing 12, a bracket 18 is secured to the bottom of the housing by screws. An opening through which the shaft 16 is inserted is formed at the bottom of the housing, and a through hole is formed at the top of the bracket 18 to which a bearing 24 that receives a part of the shaft 16 is fixed, and these openings and through holes are connected to each other. are arranged so that they are in a straight line. Further, a substrate 28 having a central hole approximately the same size as the opening is fixed to the bottom of the mirror housing with a screw, with the shaft portion 16 rotatably inserted therethrough.

Reference numeral 32 indicates an elastic ring;
For example, it is formed from a copper plate. As shown enlarged in FIG. 2, a piezoelectric element 34 is integrated into one surface of the elastic ring 32 to form a surface wave vibrator 40. The vibrator 40 is the shaft portion 1
6 and rotatably arranged coaxially and rotatably on the substrate 2.
It is fixed at 8. On the other hand, the reference numeral 36 indicates a moving body or rotor, and a plastic rubber ring or slider 38 that contacts the elastic ring 32 is adhered to one surface of the moving body. The rotor 36 can slide in the axial direction with respect to the shaft portion 16 while being prevented from rotating, and is pressed toward the vibrator 40 by a compression coil spring 42 . Reference numeral 46 is a spring 42
The spring receiver 46 is in contact with the surface of the rotor 36. The spring force of the compression coil spring 42 described above provides the minimum pressing force required by the surface wave motor.

The coil spring 4 is indicated by the reference numeral 144.
This spring receiver 144 is fixed to the shaft portion 16 by a washer 160.

Reference numeral 170 denotes a thrust ball bearing, which is disposed so as to be movable in the axial direction of the shaft portion 16 while being prevented from rotating relative to the shaft portion 16 . The flat spring 148 is fixed to the lower end of the thrust ball bearing, and the tip of the flat spring 148 is attached to the spring receiver 14.
It is in contact with 4. When the mirror housing 12 is in its normal position, the flat spring 14 is attached as shown.
Thrust ball bearing 17 due to the elastic force of 8
0 is pressed against the inside surface of the top of the bracket 18. In other words, the ball portion 170a is pressed while being positioned within the groove on the bracket side. If the mirror housing 12 receives a strong impact from the outside in this position, the bracket 1
8 rotates while pressing the thrust ball bearing 170 downward. The maximum travel distance of the thrust ball bearing 170 corresponds to the depth of the groove in the inner surface of the bracket 18, and then:
The flat spring 148 is a thrust ball bearing 170
Since the mirror housing 12 is pressed upward, the rotational speed of the mirror housing 12 is suppressed by the rolling friction force between the ball portion 170a and the inner surface of the bracket.

In addition, when rotating the mirror housing 12 from the normal position to the retracted position by remote control, the thrust ball bearing 170 can be activated by energizing the solenoid 146 in synchronization with the excitation of the piezoelectric element 34.
The solenoid 14 resists the elastic force of the flat spring 148.
6 and is moving away from the bracket 18. This allows the surface wave motor to be driven smoothly. Mirror housing 12
The same applies to the case of returning from the storage position to the normal position.

The above-mentioned spring receiver 144, solenoid 146, flat spring 148, thrust ball bearing 170
constitutes an electromagnetic friction transmission clutch interposed between the mirror base 10 and the mirror housing 12.

As shown in FIG. 3, electrodes 50 and 52 are provided on the surface of the piezoelectric element 34 described above.
A sine wave voltage from the inverter 54 to the electrode 50
V ₀ sinωt is applied, and a cosine voltage V ₀ cosωt with a phase shift of 90 degrees is applied to the electrode 52.
As a result, bimorph-type bending vibration is generated in the piezoelectric element 34 and the elastic ring 32, which becomes a traveling wave and circulates on the ring. The vibrator 40 is fixed to the mirror housing 12, and the rotor 36 is prevented from rotating around the shaft 16, so the reaction force of the rotor 36 causes the mirror housing 1 to move.
2 will be rotated. Symbol E is the ground electrode for electrodes 50 and 52. By reversing the high frequency voltages applied to the electrodes 50 and 52 using the polarity switch 56, the electrodes 50 and 52 can be rotated in the opposite direction.

A plate 62 having three conductor patterns 60 (60a to 60c) for detecting the rotational position of the mirror housing 12 is fixed on the bearing 24, as shown in FIG. Each conductive pattern 60
A bridge member 66 having three contact points 64 (64a-64c) in contact with the shaft 16 is attached to a cover member 68 secured to the shaft portion 16 by a speed nut 70. A circuit diagram for detecting the rotational position of the mirror housing 12 is shown in FIG.
When the mirror housing is in its normal position, two of the three contacts 64, namely 64a and 64b, are in contact with the corresponding conductor patterns 60a and 60b, respectively, and contact 64c is not in contact with the conductor pattern 60c. When the switch 72 is turned on in this state, a closed circuit is formed by the power source 74, the switch 72, the relay 76, the conductive pattern 60, the bridge member 66, and the diode 78, and the coil of the relay 76 is excited. The movable contact of this relay 76 is provided as a changeover switch for turning on and off the inverter 54 in FIG. 3, and the inverter 54 is turned on at the same time as the coil of the relay 76 is energized. Further, since the switch 72 and the switch 56 (FIG. 3) are designed to operate in conjunction with each other, the electrode 50 has V ₀
A high frequency voltage of V ₀ cosωt is applied to the electrode 52 and sinωt, respectively. This activates the surface wave motor and rotates the mirror housing from the normal position toward the retracted position (in the direction of arrow B in FIG. 1). When the mirror housing 12 comes to the storage position,
The contact point 64b of the bridge member 66 is connected to the conductor pattern 6.
0b, and the contact 64c comes into contact with the conductor pattern 60c. In this state, since reverse voltage is applied to diode 80, relay 7
No current flows through coil 6, and relay 76
The movable contact returns to the OFF position and the piezoelectric element 34
The excitation voltage to becomes 0, and the mirror housing 12 stops rotating.

Mirror housing 12 from storage position to normal position
In order to rotate the switch 72 back (in the direction of arrow A in FIG. 1), switch 72 from the position shown, and the
0c, bridge member 66, conductor pattern 60a,
The relay 76 and the switch 72 form one closed circuit, and the coil of the relay 76 is energized, which causes the movable contact of the relay 76 to be in the ON position. Since the switch 56 is switched in conjunction with the switch 72, a high frequency voltage of V ₀ cosωt is applied to the electrode 50 of the piezoelectric element 34, and a high frequency voltage of V ₀ sinωt is applied to the electrode 52, and the mirror housing rotates in the opposite direction. Stops at normal position.

As described above, since current flows through the solenoid 146 at the same time as a high frequency voltage is applied to the piezoelectric element 34, the thrust ball bearing 170 is attracted to the solenoid 146 against the elastic force of the flat spring 148, moves away from the bracket 18, and is moved away from the electromagnetic force. The type friction transmission clutch is in a disengaged state. As a result, only the minimum necessary spring force of the compression coil spring 42 is applied to the surface wave motor, and the surface wave motor is smoothly driven.Furthermore, when the surface wave motor is not operating, the flat spring 148 presses the thrust ball bearing 170 upward, so the rolling friction between the ball portion 170a and the inner surface of the bracket causes
The electromagnetic friction transmission clutch remains connected.

In the embodiment described above, the vibrator 40 is fixed to the mirror housing 12, and the rotor 3 is fixed to the mirror housing 12.
6 is disposed so as to be slidable in the axial direction with respect to the shaft portion 16 while being prevented from rotating around the axis, and the rotor 36 is fixed to the mirror housing 12.
The same holds true even if the vibrator 40 is disposed relative to the shaft portion 16. In this case, it goes without saying that the elastic ring 32 and the rubber ring slider 38 are arranged so as to be in face-to-face contact with each other.

[Effect of idea]

As explained above, according to the retractable door mirror of the present invention, when the mirror housing is stopped at the normal position or the retracted position, the electromagnetic friction transmission clutch interposed between the mirror base and the mirror housing is in the engaged state. Therefore, when the mirror housing receives a strong impact from the outside, the rotation speed of the mirror housing is suppressed. Also,
Since the electromagnetic friction transmission clutch is in the disengaged state when rotating the mirror housing, only the minimum necessary spring force is applied to the surface wave motor, and the mirror housing can be rotated smoothly.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the retractable door mirror of the present invention, with main parts shown in cross section. Figure 2 is an enlarged sectional view of the vibrator and rotor that make up the surface wave motor, Figure 3 is a driving circuit diagram of the surface wave motor, Figure 4 is a position detection circuit diagram of the mirror housing, and Figure 5 is a conventional storage FIG. 3 is a partially cutaway front view showing the type door mirror. 10...Base, 12...Mirror housing,
16... Shaft portion, 18... Bracket, 24... Bearing, 32... Elastic ring, 34... Piezoelectric element,
36...Rotor, 38...Rubber ring, 40...
... Vibrator, 42 ... Compression coil spring, 46
... Spring receiver, 50, 52 ... Electrode, 54 ... Inverter, 56 ... Switch, 60 ... Conductor pattern, 62 ... Plate, 64 ... Contact, 68 ...
...Cover member, 72...Switch, 76...Relay, 78...Diode, 144...Spring receiver,
146... Solenoid, 148... Flat spring, 17
0...Thrust ball bearing.

Claims (1)

[Claims for Utility Model Registration] A mirror base, a shaft portion fixed to the mirror base, a mirror housing rotatably attached to the shaft portion, and a mirror housing provided within the mirror housing concentrically with respect to the shaft portion. a surface wave motor disposed; a spring member disposed within the mirror housing and pressing the vibrator and rotor of the surface wave motor;
A retractable door mirror including an electromagnetic friction transmission clutch disposed between the mirror base and the mirror housing and energized in synchronization with the surface wave motor, wherein the electromagnetic friction transmission clutch is in a normal state. In this case, a predetermined frictional force is obtained in the joint state,
When energized in synchronization with the surface wave motor, the mirror housing is turned off and the frictional force is released so that the mirror housing can be rotated by the drive of the surface wave motor under the spring force of the spring member. A retractable door mirror featuring