JPS62244734A - Optical axis adjuster for headlamp - Google Patents

Abstract

PURPOSE:To make it correspondable to right and left tilts, by performing optical axis adjustments with the body tilt detecting sensor installed on either side in front and in the rear of a car body. CONSTITUTION:A first potentiometer 1 is interlocked with a light driving part 10, and the resistance value varies in proportion as an optical axis varied. And, a second potentiometer 21 is installed at the left in front of a car body, while a third potentiometer 22 is installed at the right in front of the car body, forming a combined resistor 2. In addition, a fourth potentiometer 32 is installed at the right in the rear of the car body, forming a second combined resistor 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical axis adjustment device for a vehicle headlamp.

[Conventional technology]

Vehicle headlights automatically adjust their optical axes according to the load. A conventional optical axis adjustment device of this type is disclosed in, for example, Japanese Patent Laid-Open No. 59-26339. This device is designed to prevent the drive motor that moves the optical axis of the headlamp in the vertical direction from being subject to an abnormally large load and burning out due to a failure of the optical axis adjustment mechanism.

FIG. 5 shows the specific circuit groove configuration,
In the figure, CON is the control circuit, MOR is the motor circuit, P R
T is a drive motor protection circuit. Further, VR+ and VR, are variable resistors for detecting the amount of vehicle height displacement, in which the movable element Sf+SrO1 moves according to the displacement stage between the vehicle body and the axle part. , VR RIr is the vehicle height displacement detection section at the front of the vehicle.

is provided at the vehicle height displacement detection section at the rear of the vehicle.

VR2 is a variable resistor for optical axis detection, and variable resistors VR,
, and VR, are connected at one terminal to the anode of the power source E via the ignition switch SW, and one terminal of the variable resistor ■RIf is connected via the balancing variable resistor VR3b. Ignition switch S
It is connected to the anode of the power source E via W. The cathode of the power source E is grounded. In addition, the anti-ignition switch side terminal of the variable resistor VR, , for detecting the amount of vehicle height displacement is directly grounded, and the variable resistor VR, , for detecting the amount of vehicle height displacement is directly grounded.
The terminal on the opposite side of the ignition switch is the variable resistor VR for balance, and the variable resistor VR for optical axis detection.

The opposite terminal of the ignition switch is grounded via a zero adjustment variable resistor VR8c.

Then, variable resistors V RIt and V
Each movable element Sf, S of R, , is connected to a comparator C0, which will be described later.
Grounded to the input terminal of M3.

Specifically, for example, the mover S7 is connected to the inverting input terminal of the comparator C0M3, and the mover Sf is connected to the non-inverting input terminal of the comparator COM3. A shaft angle setting circuit is configured.

Therefore, when the ignition switch SW is turned on, a voltage is generated between the movable elements of the variable resistors VRrt, VR, and VR and the ground. The magnitude of this voltage changes depending on the position of each movable element; when the movable element moves to the anode end of power supply E, the voltage increases, and conversely, when it moves to the ground side end, the voltage increases. becomes smaller.

Then, the voltage vSf between the movable element of the variable resistor VR+t for setting the optical axis and the ground becomes a magnitude corresponding to the ups and downs of the front of the vehicle body, and the voltage vSf between the movable element of the variable resistor VR The voltage between the movable element and the ground, VS, has a magnitude corresponding to the ups and downs of the vehicle body, and the voltage between the movable element of the variable resistor VR, and the ground, that is, the optical axis detection voltage VD, has a magnitude corresponding to the rise and fall of the vehicle body. The size depends on the angle of the optical axis.

In addition, the front vehicle height detection voltage ■Sf and the rear vehicle height detection voltage VS
, is input to the comparator C0M3 consisting of a differential amplifier,
Comparator C0M3 outputs the difference between the two voltages VS, -VS
A voltage corresponding to f is output. The output voltage VS of this comparator C0M3 is inputted as an optical axis setting voltage to the control circuit COM together with the optical axis detection voltage VD, where the optical axis detection voltage V
It is compared with D. In other words, the optical axis of a car's headlights must always be approximately parallel to the road surface, and when comparing the vehicle height at the front of the vehicle with the vehicle height at the rear, the vehicle height at the front is higher. If the height of the vehicle is higher than that of the rear side, the optical axis should be directed downward, and if the vehicle height is approximately equal on the front and rear sides, the optical axis should be pointing directly ahead. You need to orient yourself. Therefore, the angle of the optical axis to be set is determined by the relationship between the vehicle height on the front side and the vehicle height on the rear side of the vehicle. Therefore, the output voltage VS of the comparator C0M3, which compares the front vehicle height detection voltage VS and the rear vehicle height detection voltage VS, is used as the optical axis setting voltage.

In such a conventional configuration, the reference voltage of the comparator is the output voltage from the front vehicle body tilt sensor, the rear vehicle body tilt sensor, or the optical axis detection voltage, and each potentiometer (3 pieces) each have 3 wires (+
, E, output), the output voltage of each potentiometer changes, which causes the reference voltage to change, causing the problem of unstable circuit operation. . Furthermore, there is a problem in that there are many wiring locations, resulting in high costs due to materials, man-hours, etc.

The present applicant has focused on the problems of the prior art, and has developed an optical axis adjustment device for headlights that prevents circuit malfunction by blocking changes in the reference voltage, requires fewer wiring lines, and is inexpensive. is proposed.

The device has a fixed reference voltage, and consists of a tilt sensor installed at the front of the vehicle body, a tilt sensor installed at the rear of the vehicle body, and an optical axis detector connected in series, and is installed at the front and rear of the vehicle body. A tilt sensor and an optical axis detector connected in series automatically adjust the optical axis in a stable manner according to the tilt of the vehicle body.

However, in the optical axis adjustment device proposed earlier, the variable resistor for detecting the inclination of the vehicle body was installed in the front and rear of the vehicle body. Although it functions satisfactorily when the vehicle is tilted, it cannot respond to partial tilts of the vehicle, such as when the vehicle tilts to the left or right, and cannot accurately detect the tilt, so high-precision optical axis adjustment is required. This left the problem that it could not be done.

Furthermore, it was necessary to install the variable resistor at the center of the vehicle body, making it difficult to secure an installation location. The present invention has been made in view of the above-mentioned problems, and is capable of accurately detecting the longitudinal inclination of the vehicle body even when the vehicle body is tilted from side to side. The purpose is to provide a regulating device.

[Means for solving problems]

The optical axis adjustment device for a headlamp according to the present invention solves this problem by attaching detection sensors for detecting the inclination of the vehicle body to each of the left and right sides of the front and rear of the vehicle body.

[For production]

The optical axis is automatically adjusted according to the left and right inclination of the vehicle body using vehicle body inclination detection sensors attached to the left and right sides of the front and rear of the vehicle body.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4. FIG. 1 is a specific circuit configuration diagram, and 1 in the figure is a first potentiometer that is linked to the optical drive unit 10. For example, as the optical axis changes upward, the resistance value increases. Conversely, as the resistance changes downward, the resistance value decreases.

21 is the second potentiometer, located at the front left side of the vehicle body (
It is located at the top of the tire, and the resistance value increases as the part lowers.

Reference numeral 22 denotes a third potentiometer, which is installed on the front right side of the vehicle body (above the tire), and its resistance value also increases as the portion lowers, and has the same characteristics as the second potentiometer. 2 is a first composite resistor, and the second and third potentiometers 21 and 22
The combined resistance value is Reference numeral 31 designates a fourth potentiometer, which is provided on the rear left side of the vehicle body (above the tire), and its resistance value decreases as the position of the potentiometer is lowered. Reference numeral 32 designates a fifth potentiometer, which is installed on the rear right side of the vehicle body (above the tire), and the resistance value also decreases as the portion lowers, and has the same characteristics as the fourth potentiometer. 3 is the second
The combined resistor has a combined resistance value of the fourth and fifth potentiometers.

1st. The resistance value of the second composite resistor indicates the average value of the inclinations when the vehicle body is inclined in the left-right direction. Also, the second. Third. The fourth and fifth potentiometers are all connected in series, and the rates of change of the first and second combined resistors are exactly opposite, so if the front and rear of the car body are lowered by the same amount at the same time, The configuration is such that all combined resistance values do not change. One end of the fifth potentiometer 32 is grounded. One end of the second potentiometer 21 is connected to one end of the first potentiometer 1, and the connection point thereof is connected to a comparison input terminal of a comparator.

4 is a high reference voltage section, which includes resistors 41 and 42 connected in series.
One end is connected to the (+) side and the other end is connected to ground, and the connection point between both resistors that generates the higher reference voltage is connected to the reference input terminal of the first comparator 6, which will be described later. has been done. 5 is a low reference voltage section, and a resistor 5 connected in series
1 and 52, one end is connected to the (+) side and the other end is connected to ground, and the connection point of both resistors that generates the lower reference voltage is connected to the reference input terminal of the second comparator 7. It is connected. 6 is the first comparator, which has a high reference voltage (Vu)
and comparison input (Vc), and when ■,>VU, the output voltage O1 becomes rHJ level. 7 is the second comparator, which compares the low reference voltage (■) and the human power (V).

When V,>V, the output voltage 02 becomes rHJ.
level. FIG. 2 explains the output characteristics when the comparators 6.7 are connected in this way, and shows the circuit configuration and characteristics.

8 is a motor drive circuit in which the output terminal of the first comparator 6 is connected to the base of a transistor 82 via a resistor 81;
The emitter of the transistor is connected to ground, and the collector is connected to the (+) side through the coil of a relay 83. The contact 84 of the relay 83 has a normally open terminal connected to the (+) side, a normally closed terminal connected to the ground, and a common terminal connected to the motor 9.

The output terminal of the second comparator 7 is connected to the base of the transistor 8 through a resistor 85, the emitter of the transistor is connected to ground, and the collector is connected through the coil of a relay 87 (
+) side. The contact 88 of the relay 87 has a normally open terminal connected to the (+) side, a normally closed terminal connected to the ground, and a common terminal connected to the motor 9. Reference numeral 10 denotes an optical axis drive section, which changes the optical axis upward when the motor 9 rotates in the normal direction, and changes the optical axis downward when the motor 9 rotates in the reverse direction. At the same time, the first potentiometer 1 is operated and its resistance value changes. 11 is a semi-fixed resistor for initial adjustment.

In addition, 1. 2nd and 3rd. 4th. The fifth potentiometer 1, 21, 22, 31, 32 has the same function as other elements whose resistance value changes, such as a magnetoresistive element.

In addition, FIGS. 3(a), (b), and (C) are characteristic diagrams of variable resistance sensors that are vehicle body tilt detection sensors, and (
a) is a characteristic diagram of a variable resistor attached to the rear of the vehicle body. (b) is a characteristic diagram of a variable resistor attached to the front part of the vehicle body. Furthermore, (C1 is a characteristic diagram showing the characteristics of the variable resistors in the front and rear of the vehicle body at the same time.

Furthermore, Fig. 4 shows the mounting positions of potentiometers 21, 22 and 21, 32 that are mounted on the vehicle body, and the shaded area indicates the range of mounting positions of each potentiometer. located on the upper body of the tire.

Next, regarding the circuit operation of FIG. 1, first, when the present adjustment device is stopped, the comparison input voltage is between the high reference voltage and the low reference voltage (vL<Vc×Vu). Further, the initial optical axis can be adjusted using the semi-fixed resistor 11.

That is, when the front of the vehicle body lowers, the resistance value of the first composite resistor 2, which is a composite resistance of the second potentiometer 21 and the third potentiometer 22, increases, and the resistance value of the first composite resistor 2, which is the composite resistance of the second potentiometer 21 and the third potentiometer 22, increases, and the resistance value of the first composite resistor 2, which is the composite resistance of the second potentiometer 21 and the third potentiometer 22, increases, The comparison input voltage (Vc) of the comparator increases, and ■.

〉■υ, the output of the first comparator 6 becomes rHJ level, the motor drive circuit 8 is activated, the motor 9 rotates forward, and the optical axis is changed upward by the optical axis drive unit 10. 1
The resistance value of potentiometer 1 increases until the comparison input voltage V, V, <V.

(At this time, V,<V,), the output of the first comparator 6 becomes rLJ level, the motor drive circuit stops, and the motor 9 stops. With this, the optical axis is automatically adjusted to the appropriate position.

Note that if the vehicle body is also tilted left and right at this time, the first combined resistance value is a value that corresponds to the left and right tilt.

Furthermore, when the rear of the vehicle body lowers, the resistance value of the second composite resistor 3, which is the composite resistance of the fourth potentiometer 31 and the fifth potentiometer 32, decreases, so the comparison input voltage (■,) decreases. ,v,<y.

Then, the output of the second comparator 7 becomes rHJ level, the motor drive circuit 8 is activated, the motor 9 is reversely rotated, the optical axis is changed downward by the optical axis driver 10, and the first potentiometer 1 The resistance value of is decreasing. When the comparison input voltage (VC) becomes V, < VC (at this time, Vc minus Vu), the output of the second comparator 7 becomes rLJ level, the motor drive circuit stops, and the motor stops, so the light The axis is automatically adjusted to the proper position. Also at this time, if the vehicle body is tilted left and right, the resistance value of the second composite resistor 3 is a value corresponding to the left and right tilt. Furthermore, if the front and rear parts of the vehicle are lowered at the same time, the second, third, and so on. Since the combined resistance value of the fourth and fifth potentiometers 21, 22, 31, and 32 does not change, the comparison input voltage also does not change, and the optical axis does not change.

Moreover, since the switch SW is inserted into the power supply line, the circuit operation of the present device can be arbitrarily restricted and malfunctions caused by shaking of the vehicle body or the like can be prevented.

In other words, since this device operates only when this switch SW is closed, it can accurately detect when the vehicle body is tilted not only from front to back but also from side to side, and adjust the optical axis of the headlights with high precision. can.

〔Effect of the invention〕

As is clear from the above-mentioned embodiments, according to the present invention, vehicle body inclination detection sensors are provided on the left and right sides of the front of the vehicle body, and on the left and right rear sides of the vehicle body, and the optical axis is automatically adjusted in accordance with the inclination of the vehicle body. Therefore, the tilt of the front and rear of the car body,
This has the advantage that the optical axis of the headlights can be adjusted accurately and with high precision even in response to the left and right inclination of the vehicle body. Further, the mounting position of the vehicle body tilt sensor is not limited to the left and right center of the vehicle body, but may be close to the wheels, and has the advantage that relatively rough mounting is a condition.

[Brief explanation of drawings]

Fig. 1 is a circuit configuration diagram of a headlamp optical axis adjustment device showing an embodiment of the present invention, Fig. 2 is a circuit diagram of the comparator of Fig. 1 and a diagram showing output characteristics, and Fig. 3 (al. , (b). FC) is a characteristic diagram of a variable resistor which is a vehicle body tilt sensor, and FIG. 4 is a schematic plan view for explaining the mounting position of the vehicle body tilt sensor. FIG. 5 is a circuit diagram of a conventional optical axis adjustment device. 1, 21.22.3L 32... Potentiometer, 2゜3... Combined resistor, 4... High reference voltage section, 5
...Low reference voltage section, 6.7...Comparator, 8...Motor drive circuit, 9...Motor, 10...Optical axis drive section, 11...Semi-fixed resistor. Patent Applicant Ichikoh Industries Co., Ltd. Agent Patent Attorney Tadashi Akimoto Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. a first variable resistor whose resistance value changes in accordance with the direction of change of the optical axis of the headlamp; a left and right side of the front of the vehicle that are connected in series with the first variable resistor; and second and third variable resistors and fourth and fifth variable resistors, which are provided on the left and right sides of the rear, and whose resistance values change at opposite rates of change depending on the direction of inclination of the vehicle body; a high reference voltage section that generates the higher reference voltage; a low reference voltage section that generates the lower reference voltage; A first comparator that compares the potential of the reference voltage part with the potential of the low reference voltage part, and a second comparator that also compares the potential of the connection point with the potential of the low reference voltage part. It is characterized by being comprised of a motor drive circuit that rotates forward or reverse, and an optical axis drive section that changes the optical axis of the headlamp and changes the resistance value of the first variable resistor by rotation of the motor. Optical axis adjustment device for headlights.