JP2590562Y2 - Mirror control device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door mirror for a vehicle, and more particularly to an electric mirror control device which automatically stops a mirror body at a standing position and a storage position.

[0002]

2. Description of the Related Art A conventional electric mirror is disclosed in
As disclosed in Japanese Patent No. 72431, a motor circuit, a reduction gear train, a rotating portion, and a position detecting portion, a shaft mounted on a projecting portion of a base fixed to a vehicle door panel or a triangular window, The mirror body is rotatably mounted via a rotating part on the mirror mounting frame side, and the motor circuit is operated in normal and reverse directions by changing the polarity of the drive voltage by an operation switch in the cabin, thereby standing or storing the mirror body. It is turning. When the mirror body reaches the standing position or the storage position, the position of the mirror body is regulated by mechanical stopping means such as a stopper provided in the rotation range of the rotation unit, and the motor circuit is shut off by the position detection unit. It is.

In the motor circuit disclosed in the above publication, a motor and a posistor are connected in series, a diode is connected in parallel with the forward and reverse directions, and a forward and reverse rotation circuit is constituted by a contact circuit of a position detection unit. ing. The position detection unit is an electrically sliding type changeover switch whose contacts are switched at the mirror body standing position or retracted position to shut off one of the forward and reverse circuits and activate the other circuit. To However, since the diodes in the forward and reverse circuits are in opposite directions, the circuit does not operate unless the polarity of the drive voltage is switched by operating the operation switch. The position detection unit detects the position by attaching a PC board on which a slide electrode is printed to one of the mirror body rotation surface on the upper part of the shaft and the lower surface of the upper frame for mounting the motor circuit, and providing a sliding contact on the other. To form contacts,
As the mirror body rotates, the slide electrode is turned on or off by a sliding contact to shut off the motor circuit and switch to the inverting circuit.

[0004]

When the position detecting section is of the slide contact type as described above, there is a possibility that vibrations peculiar to the vehicle, poor contact due to dust and the like, and poor insulation due to moisture may occur. It is difficult to achieve perfect synchronization with the operation timing of the motor, and the stop position is likely to shift. Moreover, the assembling work in consideration of the above matters is difficult and unitization is not easy. An object of the present invention is to provide a control device for an electric retractable mirror which can solve the above-mentioned deficiencies, has good assemblability, and can operate reliably in synchronization with the operation timing of a mechanical stopping means. .

[0005]

According to the present invention, a mirror body is rotatably mounted on a shaft provided on a base overhang, and a built-in motor is rotated forward and reverse by an operation switch to achieve the above object. At the same time as stopping the mirror body at the standing or stored position by mechanical stopping means provided around the shaft,
In a door mirror that cuts off the motor circuit,
The polarity of the DC power supply is switched reversibly and the DC
Forward / reverse switching between forward and reverse rotation of the motor by applying voltage
An inverting circuit, and furthermore, the forward / reverse inverting circuit and the motor
Between the first PTC thermistor and the first diode
A non-inverting circuit composed of a series connection and a second PTC circuit
The first and second diodes have opposite polarities.
Inverting circuit composed of two diodes connected in series
This is characterized in that a parallel connection circuit is arranged.

[0006]

When the door mirror rotates to reach the standing or retracted position and its position is regulated by the mechanical stopping means of the rotating portion,
The drive of the motor is locked. At that time, an overcurrent flows through the motor, the PTC thermistor connected to the forward diode generates heat, the motor current is suppressed to 100 to 150 mA, and the circuit is almost shut off. Then, if the polarity of the drive voltage is switched by the operation switch, the diode which has blocked the current in the reverse direction with respect to the current of the circuit becomes forward with respect to the current of the circuit, and the PTC thermistor connected thereto is also changed. Since it is not overheated, a reverse current flows in the circuit where the current has been blocked, the motor reversely rotates, and the door mirror starts rotating in the reverse direction.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. FIG. 1 is a front view showing an embodiment of the present invention, wherein 1 is a base, 2 is a base overhang, 3 is a shaft standing on the base overhang 2, 4 is a frame for attaching a mirror (mirror), 5
Is a mirror body, 6 is a motor, 7 is a spring provided around a shaft, 8 is a worm provided on a motor output shaft,
9 is a worm wheel, 10 is a motor control unit, 11 is a gear box with a built-in reduction gear train, 12 is an end gear of the reduction gear train, 13 is a clutch gear that meshes with the end gear 12, and 14 is provided on the upper surface of the base overhanging part 2. It is a stopper. Note that a plurality of steel balls (not shown) are provided on the upper or lower surface of the clutch gear 13.

The motor control unit 10 includes a PC board 15 fixed to a motor and a PC board 15
PTC thermistors 16, 17 and diode 1
8 and 19. As shown in FIG. 3, a forward rotation circuit 23 in which a first PTC thermistor 16 and a diode 18 are connected in series, and a second diode 19 in which a second PTC thermistor 17 and a diode 18 are connected in series in the reverse direction. The motor 6 is connected in series to a circuit in which the reverse rotation circuit 24 and the forward / reverse rotation circuit are connected in parallel to form a motor circuit. In FIG. 3, reference numeral 20 denotes a forward / reverse inversion circuit;
21 is a connector.

The operation of the present invention will be described. In FIG. 3, when the drive current is passed in the direction of arrow N and the mirror body 5 is raised, the diode 19 is in the opposite direction.
bc is formed, and a current flows through the first PTC thermistor 16 and the diode 18. When the mirror body reaches the upright position, the mechanical stop means operates to stop the rotation, and at the same time, the motor 6 is locked in driving, so that an excessive current flows to the motor circuit. As a result, the first PTC thermistor 16 generates heat, the circuit current is suppressed to 100 to 150 mA, and the circuit is almost shut off.

When the polarity of the driving voltage is switched by the forward / reverse inverting circuit 20 to store the mirror body 5, the circuit current is switched in the direction of the dotted arrow B, so that the motor circuit cda is formed. Then, the current flows through the second PTC thermistor 17. When the mirror body reaches the storage position, the position of the mirror body is regulated by the mechanical stopping means, so that the drive of the motor 6 is locked, and an excessive current flows through the circuit as described above. Then, the second PTC thermistor 17 generates heat, and the motor current becomes 100 to
At 150 mA, the circuit is near shut off. When the mirror body continues to be stopped at the standing or stored position, the mirror body is mechanically locked at the stop position because the mechanical stopping means locks the motor on the mirror body. Will be.

[0011]

According to the present invention, a PTC thermistor is used for disconnection in place of a conventional position detection unit having a slide contact for disconnecting or switching a motor circuit as a main component. Since the connected diode was used, and the circuit interruption by the PTC thermistor was caused by the motor lock caused by the mechanical stopping means,
The stop position of the mirror is uniquely determined by the mechanical stop means, and the difference between the electrical stop position by the position detection unit and the stop position by the mechanical stop means is eliminated as in the prior art, and the assembling work is simplified. In addition, accidents caused by poor insulation and poor contact caused by the position detector can be eliminated, and since the motor is locked at the stop position, holdability of the stop position is high and position accuracy is improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a schematic configuration of an embodiment of an electric storage mirror of the present invention.

FIG. 2 is a component arrangement diagram of a motor control unit of FIG. 1;

FIG. 3 is an electrical block diagram of FIG. 1;

[Explanation of symbols]

 Reference Signs List 1 base 2 overhanging part 3 shaft 4 frame 5 mirror body 6 motor 7 coil spring 8 worm 9 worm wheel 10 motor control unit 11 gear box 12 end gear 13 clutch gear 14 stopper 15 PC board 16 PTC thermistor 17 PTC thermistor 18 diode 19 diode 20 Reversing circuit 21 Connector

Claims (1)

(57) [Scope of request for utility model registration] A mirror body is rotatably mounted on a shaft set up on a base overhang portion, and a built-in motor is rotated forward and reverse by an operation switch to rotate the mirror body, and mechanical stopping means provided around the shaft is used. At the same time as stopping the mirror body in the standing or storage position,
In a door mirror in which a motor circuit is cut off, the polarity of a DC power supply is reversibly switched so that the DC
Forward / reverse switching between forward and reverse rotation of the motor by applying voltage
An inverting circuit, and furthermore, the forward / reverse inverting circuit and the motor
Between the first PTC thermistor and the first diode in series.
Non-inverting circuit and second PTC thermistor
And a second diode having a polarity opposite to that of the first diode.
Inverter circuit composed of series connection with Iode
Mirror control device characterized by arranging a column connection circuit
Place.