JPS6358452B2 - - Google Patents

Abstract

PURPOSE:To stabilize a light-up angle adjusting drive irrespective of and variation in supply voltage as well as to make it performable with a simple electrical element. CONSTITUTION:A connection line, which connects an output line of a switch gear 40 for tilt angle indication to an emitter of a transistor TR2, is broken off and then a duty control unit is interposingly inset in the broken wires. And, when up signals a=L appear in an output line of the switch gear 40, an output transistor 54b of a relay driver 54 between these signals a=L repeats on-off operations in pulse form at a constant period. Time width in time of ON is short at a time when supply voltage is high but long when it is low. And, when the transistor TR2 of a motor driver is in a state of being energized with current, a relay RY1 is energized or intercepted by on-off operation of the transistor 54b whereby the relay RY1 gives an energizing current to a motor 10. With this constitution, a constant current is given to the motor 10 irrespective of supply voltage. Therefore, a light-up adjuster becomes stable and accurate enough.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an optical axis adjustment device for a headlight.
In particular, the present invention relates to an optical axis adjustment device for an on-vehicle headlight, which drives the on-vehicle headlamp to a retracted position and a pulled-out position, and adjusts the illumination angle in accordance with an optical axis angle instruction in the pulled-out position.

[Prior art]

For example, in a car, the angle of the optical axis of the headlight relative to the road surface changes because the amount of suspension deflection changes depending on whether there is a driver alone, a passenger, or the position and weight of loaded luggage. The angle of the optical axis is too small,
Alternatively, if the angle is too large, it will not only be difficult to drive, but if the angle is too small, it will be dangerous because it will dazzle the driver of an oncoming vehicle.

Therefore, I set up a retractable headlight.
It has been proposed to use a retractable motor to adjust the optical axis of the headlight in accordance with the vehicle height (weight) (Japanese Patent Laid-Open No. 138043/1983).

This optical axis adjustment device is equipped with a brush that rotates together with a motor that drives the headlight, and contacts that come into contact with this brush. This retractable headlight is further equipped with a contact point for adjusting the illumination point. When the light point adjustment switch is turned on when the headlight is turned on, the motor is energized by the light point adjustment contact, and the headlight points slightly downward.If you adjust the length of the light point adjustment contact, The illumination angle of the headlight can be adjusted further downward from the normal position.

French Patent Specification No. 1,592,664 discloses a system that detects the vehicle height in several stages (multi-stages) using four switches, and adjusts the irradiation angle of the headlamp in several stages accordingly.

In any of the above conventional examples, the irradiation angle is automatically determined by selectively connecting the brush provided in the headlamp tilting mechanism and the sensor switch to energize and stop the motor in forward and reverse directions.

In this type of retractable headlamp device that positions the headlamp between the retracted position and the pulled-out position, a retract motor that drives the headlamp between the retracted position and the pulled-out position and a retractable motor that drives the headlamp between the retracted position and the pulled-out position and the angle of the optical axis of the headlamp in the pulled-out position, that is, the irradiation angle, are adjusted to the vehicle body. It is preferable that the lamp drive mechanism includes only one electric motor, in common with a motor for finely adjusting the illumination angle according to the vehicle height or inclination of the lamp.

However, if the motor is simply shared, the drive stroke is large in the retract drive, and it is preferable to drive from the storage position to the pull-out position or vice versa relatively quickly, and for this reason, the motor must be driven with high torque. When adjusting the illumination angle at the drawer position, it is necessary to
Since the adjustment range is narrow and fine adjustments are required, it is not necessary to drive the motor at high speed; rather, in order to achieve control accuracy, it is recommended to drive the motor at low speed to avoid overruns. preferable. As described above, in terms of motor energization, the retract drive and the irradiation angle adjustment drive have contradictory demands.

Such a request is achieved by setting the motor applied voltage and/or energizing current in two stages: in retract drive, the applied voltage (current) is increased to achieve high torque drive, and in adjustment drive, the applied voltage (current) is lowered to achieve high torque. Just drive it.

But there is a further problem. This is because the motor power supply voltage fluctuates widely on a vehicle, and the torque and/or speed of the motor fluctuates depending on the voltage. Therefore, if the adjustment drive is set so that a low current that does not cause overrun flows through the motor, it may become difficult to drive the lamp up when the on-board battery voltage drops, or conversely, it may become difficult to drive the lamp up even at low voltage. If a current is set to flow through the motor to enable up-drive, overrun may occur during adjustment drive when the voltage of the on-board battery is high.

This problem can be solved by passing current to the motor through a constant voltage circuit, but since the starting current of the motor is around 20A and the fluctuation range of battery voltage is extremely large, a constant voltage circuit is not suitable for high voltage circuits. The current capacity and voltage control range are quite wide, and the capacity is extremely large, making it difficult to put it into practical use at present.

[Purpose of the invention]

The present invention provides stable illumination angle adjustment drive despite fluctuations in motor power supply voltage, and
The aim is to do this with as simple an electrical element as possible.

[Structure of the invention]

In order to achieve the above object, in the present invention,
The lamp drive mechanism includes one electric motor, supports the headlamp, drives the headlamp to the retracted position and the drawn-out position, and adjusts the irradiation angle at the drawn-out position; a rotation angle sensor for indicating the tilt angle of the lamp optical axis; and a tilt angle indicating means for indicating the tilt angle of the lamp optical axis; A motor that selectively energizes or deenergizes an electric motor in accordance with a motor energization control signal and applies an energizing current to the motor in accordance with an energizing current value control signal. The motor includes a driver; and energizing current value control means that detects the motor power supply voltage and generates the energizing current value control signal that instructs the energizing current value according to the detected voltage.

According to this, since the motor current value is controlled according to the motor power supply voltage, the motor rotates with a desired torque despite fluctuations in the power supply voltage. Such current value control can be easily implemented using a relatively simple combination of electrical elements, as will be clear from the embodiments described below.

In a preferred embodiment of the present invention, the control signal generating means includes a retract switch that instructs the headlamp to be driven to the retracted position and the extended position; the motor driver controls the motor energizing current in response to instructions from the retract switch. A relay is included that lowers the motor energizing current for motor energizing when adjusting the irradiation angle.

According to this, in the retract drive, the headlamp is driven quickly with high torque. Irradiation angle adjustment is performed accurately and reliably with low torque, and is virtually unaffected by fluctuations in power supply voltage.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

〔Example〕

FIG. 1 shows the appearance of a lamp drive mechanism according to an embodiment of the present invention. The headlamp 1 is a right headlamp arranged on the right side of the vehicle facing forward. The headlamp 1 is rotatably supported at one end by a bracket 3 via a pin 2, and the bracket 3 is fixed to a vehicle body 4. A ring 6 is rotatably supported on the headlamp 1 by a pin 5, and the other end of the link 6 is supported pivotally on an arm 7. The arm 7 is fixed to a drive shaft 9 of a speed reduction mechanism 8. An electric motor 10 is connected to the input shaft of the speed reduction mechanism 8.
The rotating shafts of the two are connected.

In the above configuration, pin 2 to motor 10 constitute a headlamp drive mechanism. FIG. 1 shows the headlamp 1 in an upright position (in the drawn-out position). When the motor 10 rotates in this state, the drive shaft 9 and the arm 7 rotate, thereby the link 6 moves downward, and the headlamp 1 rotates downward about the pin 2 and is stored.

FIG. 2 shows the speed reduction mechanism 8. The speed reduction mechanism 8 includes
A reduction gear 11 is connected to the output shaft of the motor 10 and transmits rotational force to the drive shaft 9.
This reduction gear 11 is equipped with a rotation angle sensor 12. This sensor 12 is composed of a brush plate 13 and a brush 14.

FIG. 3 shows the relative relationship between the brush plate 13 and the brush 14. The hatched portion of the brush plate 13 indicates an insulating portion. Also brazi 14
n, 14 ₁ , 14 ₂ , 14 ₃ , 14 ₄ , 14a, 14
b, 14c, 14d, 14e, 14g are brush contacts Sn, S ₁ , S ₂ , S ₃ , S ₄ , Sa, Sb, respectively.
It is provided with Sc, Sd, Se, and Sg, and is in contact with the brush plate 13 at this brush contact point. In addition, motor 1
0 rotation, the brush plate 13 rotates.

In addition to the above-mentioned right lamp, there is a left lamp as a headlamp, and the left lamp is also equipped with a similar drive mechanism, reduction gear, and rotation angle sensor.

FIG. 4 shows a manually operated knob 41 provided as an inclination angle indicating means. The manual operation knob 41 is fitted onto the shaft 21 of the tilt angle indicating switch device 40. The switch device 40 is installed around the driver's seat in the vehicle, and a manual operation knob 41 is arranged in a manner that is exposed inside the vehicle. A rotation direction detection switch SW3 is fixed to the shaft 21 of the manual operation knob 41, and normally a spring 22 causes a contact 23 (output end 27) to be open and a contact 24 (output end 25) to be open.
When the manual operation knob 41 is rotated clockwise, that is, in a direction that lowers the optical axis of the headlamp,
The contact 23 is closed, the contact 24 is opened, and the operating knob 41 rotates. When the operating knob 41 is rotated to a predetermined position and released, the spring 22 opens the contact 23 (output end 27), and the contact 24 (output end 27) opens.
5) is closed.

FIG. 5 shows the connection relationship between the above-mentioned equipment of the right lamp and the tilt angle indicating switch 40 provided with a manually operated knob. A manual knob 41 is fixed to the rotation shaft 21 of the tilt angle indicating switch device 40 . First set of five contacts 43n, 43
₁ , 43 ₂ , 43 ₃ , 43 ₄ are brush contacts, respectively.
Connected to Sn, S ₁ , S ₂ , S ₃ , and S ₄ . The electrical lines making these connections are the control signal generating means in this embodiment. The first selector 43 is shaped so that it can simultaneously contact only four of the five contacts of the first set, and similarly
The selector 44 also selects 4 of the 5 contacts of the second set.
It is shaped so that it can touch only the individual at the same time.

A first set of five contacts, a second set of five contacts, and first and second selectors are similarly provided for the left lamp. 1st for right lamp
The second selectors 43, 44 and the first and second selectors for the left lamp are fixed to the same rotating shaft 21, and the manually operated knob 4 is attached to the rotating shaft 21.
1 is fixed and a manually operated knob 41 is attached to this rotating shaft 21.
is fixed. The first selector 43 is connected to the emitter of a transistor TR1, and the collector of this transistor TR1 is connected to a relay RY2 and a diode D1. This diode D1 is further connected to the contact 27 of the rotation direction detection switch SW3 and the base of the transistor TR3. Further, the contact 25 of the rotation direction detection switch SW3 is connected to the base of the transistor TR3. Next, the second selector 44 is connected to the emitter of the transistor TR2, and the collector of this transistor TR2 is connected to the common contact Sc of the relay RY1 and the changeover switch SW1. Further, the relay RY3 is connected to the common contact Sc of the changeover switch SW1. Here, the state shown in FIG. 5 shows that relays RY1, RY2, and RY3 are all off. The connection for the left lamp is also similar.

Next, the first selector 43 and the second selector 4
When the knob 4 indicates "1", the first selector 43 contacts the contact 43n, does not contact any of the other contacts 43 ₁ to 43 ₄ , and selects the second selector 43n. 44 is shaped and arranged so that it does not contact the contacts 44n and 44 ₁ but contacts the other contacts 44 ₂ and 44 ₄ . When the knob indicates "3", the first selector 43 selects the contacts 43n, 4.
3 ₁ and 43 ₂ , and the second selector 44 contacts only the contact 44 ₄ . The contact and selector combination for the left lamp is also quite similar to that for the right lamp.

In addition, although FIG. 5 shows two sets of contacts and two selectors distributed on a plane, two drawer contacts each contacting two sets of contacts and two sets of selectors The selectors are formed on the same printed circuit board concentrically and on the same plane with different radii, and each selector has brushes that contact four contacts, and the drawer connection brush connects to the ring-shaped drawer. It is in constant contact with one of the contacts.

The resistor R1 is a limiting resistor that lowers the value of current flowing to the motor 10. This resistor R1 is connected in series with the motor 10 by a relay RY3 during optical axis adjustment.

Further, the contacts Sa, Sb and Sc of the changeover switch SW1 are switched by brush contacts of the rotation angle sensor 12 shown in FIG.

In addition, when retracting switch SW2 is turned to the UP side, the head lamp will stand up.
When you flip the switch to the down side, the headlamp will be retracted.

In the above configuration, relays RY1, RY2,
RY3 and transistors TR1 to TR4 constitute a motor driver.

The components explained above are the main body of the adjustment device, and resistors 50 and 5 for detecting motor power supply voltage are used as energizing current value control means to be explained below.
1, comparator 52, oscillator 53, relay driver 5
4, a voltage responsive duty control device composed of a duty control synchronization circuit 55, a constant voltage resistor 56, and a constant voltage diode 57 is connected. This voltage-responsive duty control device was originally designed to control the output line (from 40 to 55) of the tilt angle indicating switch device 40.
In order to carry out the present invention, the line connected to the emitter of transistor TR2 is connected to the emitter of transistor TR2.
The connection wire is broken and a duty control device is inserted there, and the switch device 40 outputs an up signal a=L according to the output of the tilt angle indicating switch device 40 (up signal a=L) and the power supply voltage (12V). While outputting L, instead of this up signal a, a relay drive signal c with a duty corresponding to the power supply voltage is applied to the emitter of the transistor TR2.

That is, when the up signal a=L does not appear on the output line of the tilt angle indicating switch device 40 (a=H), the duty control synchronization circuit 55
The transistor 55a is on, which causes the transistor 55b to be on, forcing the cathode side of the diode D2 to become H (connected to the power supply side).
Therefore, a reverse voltage is applied to the diode D2, and the voltage at the positive phase input terminal (+) of the operational amplifier 53a is fixed to the voltage Vz of the constant voltage diode 57. Therefore, if the voltage at the negative phase input terminal (-) is lower than Vz, it will rise, if it is higher, it will fall and stabilize at Vz,
The output of the oscillator 53 is stabilized at the plus peak level of the triangular wave. As a result, the output of the comparator 52 is L.
In this case, the transistor 54a of the relay driver 54 is off, but since the transistor 55a is on, the transistor 54a passes through the diode D3.
Transistor 5 to draw in the base potential of 4b
Transistor 54b is off regardless of the state of transistor 4a. With this transistor 54b,
The emitter of the motor driver's transistor TR2 and the device ground are cut off, and the relay RY2 is not energized.

When the up signal a=L appears on the output line of the tilt angle indicating switch device 40, the transistor 55a of the duty control synchronization circuit 55 is turned off, which turns off the transistor 55b, and the voltage on the cathode side of the diode D2 becomes It is cut off from the power supply line and only the output of the operational amplifier 53a is controlled. For example, when the voltage at the negative phase input terminal (-) of the operational amplifier 53a is higher than Vz, the output of the amplifier 53a becomes L, and the input voltage at the positive phase input terminal (+) of the amplifier 53a is Vz divided by the resistors 60 and 62. The voltage will be increased.

In addition, the capacitor 53b is also discharged to the output terminal of the amplifier 53a through the resistor 61, and the input voltage at the negative phase input terminal (-) falls, and when it reaches the voltage obtained by dividing Vz by the resistors 60 and 62, the output of the amplifier 53a becomes H. becomes.

This time, the input voltage at the positive phase input terminal (+) of the amplifier 53a returns to Vz and is applied to the capacitor 53 through the resistor 61.
b is charged, and the negative phase input terminal (-) of the amplifier 53a
Input voltage increases. This is repeated while a=L, and the oscillator 53 outputs a triangular wave voltage.

In this way, the tilt angle indicating switch device 4
When the up signal a=L appears on the 0 output line, the oscillator 53 starts oscillating from the plus peak level of the triangular wave, and provides a triangular wave voltage to the comparator 52.

The comparator 52 is H when the triangular wave voltage is lower than the voltage of the resistor 51;
When the voltage exceeds , a voltage of L is applied to the relay driver 54.

The relay driver 54 is configured so that the output of the comparator 52 is L.
When , the emitter of transistor TR2 of the motor driver is connected to equipment ground, and when it is H, it is disconnected from equipment ground.

On the other hand, since the voltage obtained by dividing the power supply voltage (12V) by the resistors 50 and 51 is applied to the positive phase input terminal (+) of the comparator 52, the duty of the output of the comparator 52 is determined by the power supply voltage, and the power supply voltage is Low and comparator 52
The L time of the output of transistor TR2, that is, the time when the emitter of transistor TR2 is connected to the device ground becomes longer, and the opposite is true when the power supply voltage is high.

As a result of the above operation, when the up signal a=L appears on the output line of the tilt angle indicating switch device 40, the output transistor 54b of the relay driver 54 turns on and off in a pulsed manner at regular intervals while a=L. Repeatedly, when the power supply voltage is high, the ON time width becomes short, and when the power supply voltage is low, it becomes long. When the transistor TR2 of the motor driver is in a conductive state, the relay is activated by turning on and off the transistor 54b.
RY1 is energized and cut off. This relay RY1 applies an energizing current to the motor 10, and in this case, a constant current is applied to the motor 10 regardless of the power supply voltage.

Next, the retraction drive and irradiation angle adjustment drive of the headlight using the electric circuit shown in FIG. 5 will be explained. Since the left and right lights are tilted in exactly the same way and are performed at the same time, only the operation of the right light will be described below.

First, the raising and retracting operations of the headlamp, that is, the retract drive will be explained. FIG. 5 shows the headlamp in an upright position. In this state, when the retract switch SW2 is turned to the down side, the contact Sb of the changeover switch SW1 is grounded to the equipment (hereinafter simply referred to as grounding or grounding). For this reason, the relay
RY1 and relay RY3 conduct and motor 10
rotates in the normal direction, thereby retracting the headlamp. At this time, the brush plate 13 rotates in accordance with the rotation of the motor 10, and when the headlamp reaches a predetermined storage position, the brush contact Sb contacts the insulating part of the brush plate 13, and the brush contact Sa contacts the conductor of the brush plate 13. the selector switch
By switching SW1, relay RY1 and relay RY3 are cut off, and motor 10 is stopped.

Next, when the retract switch SW2 is turned to the UP side, the changeover switch SW1 is switched to the contact Sa side, and the contact Sa of the changeover switch SW1 is grounded. Therefore, relay RY1 and relay
RY3 becomes conductive and the motor 10 rotates in the forward direction, thereby causing the headlight to stand up. At this time, similarly to the retracting operation, when the motor 10 rotates forward and the headlamp reaches a predetermined standing position, the brush contact Sa contacts the insulating part of the brush plate 13, and the brush contact Sb contacts the conductive part of the brush plate 13. By switching switch SW1, relay RY1
Then, relay RY3 is cut off and motor 10 is stopped.

Next, the illumination angle adjustment drive will be explained. now,
Manual operation knob 4 of the tilt angle indicating switch device 40
1 is in the "1" position and the headlamp is set at the indicated position, the selector Sg of the rotation angle sensor 12 is set to the contact position as shown in FIG.
It is in contact with S ₁ . In this state,
The first and second tilt angle indicating switch devices 40
Since the selectors 43 and 44 are not in contact with the contacts 43 ₁ and 44 ₁ , relay RY1 and relay RY2
is not energized and the motor 10 is stopped.

Here, when the knob 41 is rotated one step clockwise, the first tilt angle indicating switch device 40 is rotated.
The selector 43 connects the contacts 43n and ₄₃₁ to the second
The selector 44 contacts the contacts 44 ₃ and 44 ₄ . At this time, as mentioned above, the rotation direction detection switch
Contact 27 of SW3 is closed. Therefore, the base of the transistor TR3 is grounded, turning off the transistor TR3 and turning on the transistor TR4. Therefore, a predetermined voltage is applied to the base of the transistor TR1.

On the other hand, in the rotation angle sensor 12, since the selector Sg is connected to the contact _S1 , the contact ₄₃₁ of the tilt angle indicating switch device 40 is connected to the ground, and the transistor TR1 is connected via the first selector 43. The emitter of the transistor TR1 is connected to ground, and the transistor TR1 is turned on. By the way, relay RY
2 is energized, and the motor 10 is energized to reverse rotation. At this time, once the transistor TR1 is turned on, the base of the transistor TR3 is grounded by the diode D1, so that the relay RY2 continues to be energized. This causes the selector Sg of the rotation angle sensor 12 to rotate counterclockwise. When the selector Sg comes into contact with the contact _S2 , the selector Sg becomes a floating state and the energization to the relay RY2 is stopped. Similarly, each time the knob of the tilt angle indicating switch device 40 is rotated one step clockwise, the motor 10 rotates the selector Sg of the rotation angle sensor 12 one step counterclockwise and then stops. It will be done.

Here, the headlamp does not stop at a predetermined position and overruns, causing the selector of the rotation angle sensor 12 to
If Sg does not stop at contact S ₂ and overruns to contact S ₃ , the second selector 44
Since it is in contact with 4 ₃ , it is connected to ground via selector Sg. As a result, the up signal a=L is applied to the duty control synchronization circuit 55, and the transistor 54b of the relay driver 54 starts turning on and off with a duty according to the power supply voltage. At this time, since the contact 25 of the rotational direction detection switch SW3 is closed, the transistor TR3 is on and the transistor TR4 is off, so an on voltage is applied to the base of the transistor TR2. Therefore, when the second selector 44 is grounded (when the up signal a=L is generated), the transistor TR2 turns on and off with a duty according to the power supply voltage, and the relay RY1 turns on and off. Power is turned on and off in synchronization. As a result, a pulsed current flows through the motor 10 with a duty corresponding to the power supply voltage, and the motor 10 reverses.
When the selector Sg rotates clockwise and contacts the contact _S2 , the selector Sg becomes floating and the up signal a=L to the duty control synchronization circuit 55 disappears (a=H). In response, transistor 55a of circuit 55 is turned on, transistor 55b is turned on, and oscillator 53
stops oscillating when its output reaches the plus peak level, and as a result, the output of the comparator 52 becomes H, the transistor 54b is turned off, and the current supply to the relay RY1 is stopped. In this way, if an overrun occurs when the optical axis of the headlamp is lowered, it is automatically raised and stopped at a predetermined position. During this rise, as mentioned above, the motor 10 is driven at a constant current by duty control corresponding to the power supply voltage, so there is no excess or deficiency of drive torque, no overrun, no drive failure, and stable operation. Stops at a predetermined position.

Contrary to the above, for example, when the knob of the tilt angle indicating switch device 40 is in the "3" position, the first selector 43 is connected to the contacts 43n, ₄₃₁ and _432.
, the second selector 44 is in contact with only the contact ₄₄₄ , and in the rotation angle sensor 12, the selector Sg is correspondingly in contact with the contact _S3 , and the knob is turned back. When rotated one step clockwise, the first selector 43 contacts only the contacts 43n and ₄₃₁ , and the second selector 44 contacts the contacts ₄₄₃ and ₄₄₄ .

At this time, as mentioned above, turn on the rotation direction detection switch.
The contact 25 of SW3 remains closed. Therefore, when the second selector 44 is connected to ground via the selector Sg, the up signal a=L is given to the circuit 55, the transistor TR2 is turned on, and the transistor of the relay driver 54 is turned on with a duty corresponding to the power supply voltage. 54b is turned on and off, a constant current (pulsed) flows through the motor 10, and the motor 10 rotates in reverse. This rotates selector Sg clockwise,
Selector Sg is in a floating state (a=H), transistor 54b of relay driver 54 is turned off, and pulse energization to relay RY1 is stopped.

FIG. 6 shows the relationship between the up signal a, the down signal b, and the relay drive signal c when adjusting the illumination angle.

Note that as long as the settings are the same, the left lamp also performs the same operation as the right lamp at the same time.

In the above embodiment, in the headlamp down drive in illumination angle adjustment, duty control is not performed to keep the motor torque constant despite fluctuations in the power supply voltage. This means that in case of down
This is because the motor load is small, so motor torque fluctuations do not have a large effect, and even if an overrun occurs, the next up drive returns it to the predetermined position with constant torque drive. Also,
In retract drive, the lamp is only driven to the upright position (drawn out position) or retracted position, so
There is no need for particularly detailed positioning control; rather, high-torque and fast driving is desired. Therefore, in the retract drive, the resistor R1 is short-circuited to achieve high torque drive, and constant current control is not performed.

〔Effect of the invention〕

As explained above, in the motor energization mode in which illumination angle adjustment becomes unstable due to fluctuations in the motor power supply voltage, the present invention applies an energizing current corresponding to the motor power supply voltage to the motor to drive the motor at a constant torque. Therefore, the irradiation angle adjustment drive is stable and accurate, and can be easily performed by combining extremely simple electric elements. A large capacity constant voltage device is not required.

[Brief explanation of drawings]

FIG. 1 is a side view showing the appearance of a lamp drive mechanism according to an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the speed reduction mechanism 8 shown in FIG. 1. FIG. 3 is a plan view of the brush plate 13 of the rotation angle sensor 12 incorporated in the deceleration mechanism 8, and also shows the arrangement relationship between the contact points of the plate 13 and the brush. FIG. 4 is a partial cross-sectional view showing the manually operated knob and rotation direction detection switch, FIG. 5 is an electric circuit diagram showing the entire electric circuit configuration of this embodiment, and FIG.
It is a waveform diagram which shows the state of c. 1: Headlamp, 2, 5: Pin 3: Bracket, 6: Link 7: Arm, 8: Reduction mechanism 10: Motor (The above is the headlamp drive mechanism) 12: Rotation angle sensor 40: Tilt angle indicating switch device (tilt angle indicating means) Connection between the rotation angle sensor 12 and the switch device 40 and the connection including the retract switch SW2 (The above are control signal generation means) RY1, RY2, RY3: Motor drive relay R1: Current limiting resistor TR1 to TR4: Transistor D1: Diode (The above are motor drivers) 50, 51: Voltage dividing resistor, 52: Comparator 53: Oscillator, 54: Relay driver 55: Duty control synchronous circuit, 56: Resistor 57: Constant voltage diode (The above is the energizing current value control means) SW1: Changeover switch, SW2: Retract switch SW3: Rotation direction detection switch.

Claims (1)

[Scope of Claims] 1. A lamp drive mechanism including one electric motor, supporting a headlamp, driving the headlamp to a retracted position and a drawn-out position, and driving the irradiation angle adjustment in the drawn-out position; a rotation angle sensor that detects the tilt angle of the lamp; tilt angle indicating means that indicates the tilt angle of the lamp optical axis; a control signal generating means for generating an energizing control signal; a motor driver that selectively energizes and deenergizes the electric motor in accordance with the motor energizing control signal and applies an energizing current to the motor in accordance with the energizing current value control signal; and energizing current value control means for detecting a motor power supply voltage and generating the energizing current value control signal for instructing a energizing current value according to the detected voltage. 2. The control signal generating means includes a retract switch that instructs to drive the headlamp to the retracted position and the drawn position; the motor driver increases the motor energizing current in response to instructions from the retract switch; The optical axis adjustment device for a headlight according to claim 1, further comprising a relay that lowers the motor energizing current when the motor is not energized.