JPH06483B2 - Vehicle headlight optical axis adjustment device - Google Patents

Abstract

PURPOSE:To prevent an overrun of downward turn of a headlight owing to the gravity, by controlling to drive the downward turn of the headlight at a speed lower than that of the upward turn. CONSTITUTION:A headlight 1 is installed to turn driven by a motor 9 which can be controlled to drive in the direct and reverse directions and connected to a control unit 20. Responding to the direct and reverse rotations of the motor 9, the headlight 1 is turned upward and downward respectively, and the downward turn is set to be at a lower speed than the upward turn. Therefore, even though a downward inertia is produced by the gravity of the housing 2, an overrun of the downward turn of the headlight 1 is avoided perfectly and the headlight is kept at the desirable position with a high accuracy, since the downward turn of the headlight 1 is slower than the upward turn.

Description

Description: TECHNICAL FIELD The present invention relates to an optical axis adjusting device for a vehicle headlight that vertically drives a headlight by a motor or the like to adjust the optical axis of the headlight. .

[Prior Art] Conventionally, in a device that uses a motor to rotate headlights in the up-down direction, the motor is continuously driven at the same speed in the up-down direction, and when the optical axis angle reaches a target position, power is turned on. Had been stopped.

[Problems to be Solved by the Invention] However, in the above configuration, when the headlight is rotated downward, gravity acting on the headlight is added to the rotational force of the motor, so that the rotation speed is higher than that in the case of upward rotation. And get faster. Therefore, in the case of downward rotation, the amount of overrun with respect to the target angle becomes larger than upward,
There is a problem that the headlight is displaced from the target optical axis.

The present invention has been made in order to solve the above-mentioned problems of the conventional technique, and is for a vehicle headlight that can stop the headlight at a predetermined target position when the headlight is rotationally driven downward. An object is to provide an optical axis adjusting device.

[Means for Solving the Problems] The present invention made to achieve the above object is to provide a driving means for rotating a headlight mounted on a vehicle in a vertical direction, and a driving means for driving the headlight in a downward direction from an upward direction. Is provided with a control means for variably controlling the driving speed at a slower speed.

Here, the drive means refers to a direct current motor, a pulse motor, etc., and the control means means to control the drive means by current or voltage, such as variable frequency, variable duty ratio, or current / voltage value. It includes means for variably controlling the amount of electricity.

[Operation] In a device in which the headlight is driven in the vertical direction by the rotation driving means, an inertial force corresponding to gravity is applied when the headlight is driven in the downward direction, and the headlight overruns and stops. According to the present invention, the driving speed in the downward direction is controlled to be slower than the driving speed in the upward direction, so that the overrun of the rotational driving of the headlight is completely eliminated, and the headlight is stopped with high accuracy. Because you can
There is no deviation of the optical axis when driving, and comfortable driving is possible.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.
In FIG. 2, reference numeral 1 is a headlight, and an operating wheel 3 is attached to a side portion of a housing 2 of the light 1.
Handwheel 7 via link 4, actuating wheel 5 and link 6
Is connected to the operating vehicle 7a. One end of the shaft 8 of the flywheel 7 is mounted so as to be rotationally driven by a motor 9. The motor 9 is connected to the control means 20 and is variably controlled so that it can rotate forward and backward.

The control means 20 is configured as a circuit as shown in FIG. 1, and 30u is connected to a central control unit (MCU) 22 with a resistor 3 connected thereto.
A transistor connected via 1u and 32u,
A diode 33 is provided on the output side of the transistor 30u.
It is connected to the DC power supply 36 via u and the relay 34u. One fixed contact 34ua of the relay 34u is connected to the power source 36, the other fixed contact 34ub is connected to the frequency drive circuit 40, and the movable contact 34uc is connected to the DC motor 9.
It is connected to the.

On the other hand, the transistor 30d, the resistors 31d and 32d, the diode 33d, and the relay 34d are
u, the relay 34u, etc. are connected.

Light switching means 5 connected to the MCU 22
0 is an upward switch 5 for the headlight 1 (Fig. 2)
0u and a downward switch 50d.

In the above configuration, the output signal from the MCU 22 causes
When the transistor 30u is turned on and the transistor 30d is turned off, the relay 34u is turned on to connect the movable contact 34uc to the fixed contact 34ua, and the terminal 9a of the DC motor 9 is connected.
Is connected to the current power source 36, while the relay 34d is turned off to connect the movable contact 34dc to the fixed contact 34d, and the terminal 9b of the DC motor 9 is connected to the frequency drive circuit 40. As a result, the DC motor 9 is rotationally driven so that the headlight 1 is directed upward.

On the other hand, the transistor 30u is off and the transistor 30d is
When is turned on, the relay 34u is turned off, the terminal 9a of the DC motor 9 is connected to the frequency drive circuit 40, the relay 34d is turned on, and the terminal 9b is connected to the DC power supply 36. As a result, the DC motor 9
Rotates in the reverse direction to the above case, and rotationally drives so that the headlight 1 faces downward.

When the transistors 30u and 30d are both off, the relays 34u and 34d are both off, the terminals 9a and 9b of the DC motor 9 are short-circuited, and the motor 9 is stopped.

As shown in FIG. 3, the frequency drive circuit 40 includes an oscillator 75A including resistors 70a and 71a, inverters 72a and 73a, and a capacitor 74a, and resistors 70b and 7A.
1b, inverters 72b and 73b, and capacitor 74
and an oscillator 75B consisting of b, and FIG.
As shown in (B), the time constant is such that the oscillator 75B oscillates at a higher frequency than the oscillator 75A.
The outputs of both oscillators 75A and 75B are connected to one input terminals of the gates 74 and 75, respectively, and the other input terminal of the gate 74 is connected to the MCU 22 and the other input terminal of the gate 75 is connected to the MCU 22 via the inverter 76. It is connected. The output sides of the gates 74 and 75 are connected to the input terminal of the gate 77. The output side of the gate 77 is connected to the interface transistor 79 via the resistors 78a and 78b, and further via the diode 80 and the resistor 81. The power transistor 82 is connected to the power transistor 82, and the power transistor 82 is connected to the relays 34u and 34d.

In the frequency drive circuit 40, the oscillators 75A, 75
The output of B is input to the gates 74 and 75, respectively. The U / D signal from the MCU 22 is input to the other inputs of the gates 75 and 74. When the U / D signal is at the H level, the gate 74 is turned on to output the oscillation frequency signal of the oscillator 75A, When the / D signal is at the L level, it is inverted by the inverter 76 so that the gate 75 becomes conductive and the oscillator 75B
The oscillation frequency signal of is output. Therefore, the power transistor 82 is the interface transistor 80.
That is, the U / D signal is driven at an H level at a low frequency shown in FIG. 4 (A), and the U / D signal is driven at an L level at a high frequency shown in FIG. 4 (B). Driven.

Next, the operation will be described with reference to the flowchart of FIG. Now, when the upward switch 50u shown in FIG. 1 is turned on, the input to the MCU 22 changes from H level to L level. This allows
In step 100 of the flowchart of FIG. 5, it is determined that the upward switch 50u is on, and the process proceeds to step 110, in which a signal from the MCU 22 turns on the transistor 30u and turns off the transistor 30d, so that U /
The D signal is set to H level. As a result, the DC motor 9 is driven at the frequency of the oscillator 75A shown in FIG. 3 (FIG. 4A), and the headlight 1 shown in FIG. 2 is driven upward.

On the other hand, when the downward switch 50d (FIG. 1) is turned on, the input to the MCU 22 changes from the H level to the L level, and the downward switch 50d is turned on in step 120 of the flowchart of FIG. Is determined, and the process proceeds to step 130. In step 130, the MCU 22
Turns off the transistor 30u, turns on the transistor 30d, sets the U / D signal to L level, drives the DC motor 9 at the frequency of the oscillator 75B in FIG. 3 (FIG. 4B), and is shown in FIG. The headlight 1 is driven downward.

In addition, the upward switch 50u and the downward switch 50
When both d are off, the inputs to the MCU 22 are both H
At the level, proceed to step 140 in FIG.
Turns off the transistors 30u and 30d in FIG. 1 to stop the DC motor 9.

In the above operation, the driving frequency becomes higher, that is, the rotational force becomes smaller, when the headlight 1 is driven downward than when it is driven upward. Therefore, due to the gravity of the housing 2 of the headlight 1 and the like, an inertial force that tries to speed up the driving force acts when driving downward, but since the rotational force for downward driving is set small, the target stop position It is possible to stop at a predetermined position by eliminating the amount of overrun.

Instead of the oscillators 75A and 75B, the MCU2
2 may oscillate directly to drive the transistor.

Further, instead of selecting the upward rotation or the downward rotation with the upward and downward switches 50u and 50d, the vehicle speed signal or the vehicle height signal is input to the MCU, and the MCU rotates upward from the signal state, The downward rotation may be selected.

Furthermore, a DC motor is controlled by a constant current power supply to change the current value, or a constant voltage power supply is used to change the voltage value, or the DC motor is driven by a duty wave to change the duty ratio. A method of changing and controlling may be used. In this case, for example, the one-chip microcomputer MBL6
By using the output compare function of 803, duty control can be easily performed.

[Advantages of the Invention] As described above, according to the present invention, when the headlight is rotationally driven downward, the headlight can be stopped at the target position with high accuracy.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment according to the present invention, FIG. 2 is a schematic configuration diagram of the embodiment, FIG. 3 is a circuit diagram showing an essential part of the embodiment, and FIG. Waveform diagram for explaining the operation, No. 5
The figure is a flowchart according to the embodiment. DESCRIPTION OF SYMBOLS 1 ... Headlight 9 ... DC motor (driving means) 20 ... Control means 40 ... Frequency drive circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuhiro Saka, 1-1, Showa-cho, Kariya city, Aichi Nihon Denso Co., Ltd. (56) Reference JP-A-60-35636 (JP, A)

Claims (1)

[Claims] 1. A drive means for rotatably driving a headlight mounted on a vehicle in an up-down direction, and a control means for variably controlling the drive means at a lower drive speed in a downward direction than in an upward direction. Optical axis adjustment device for vehicle headlights.