JPS6029347A - Optical axis adjusting device for headlight - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for adjusting the optical axis of a vehicle headlamp by operating a knob according to the load 20.As a conventional headlamp optical axis adjustment device, For example, there is one shown in FIG. The potentiometer 1 is switched as desired by operating a knob. The potentiometer 2 switches according to changes in the optical axis of the headlight. 3 is a comparison circuit that compares the output voltages of potentiometer 1 and potentiometer 2 and outputs the result. 4 is a motor drive circuit, and as a result of the comparison of the comparison circuit, if an output signal is output to 3a, the transistor Trl is turned on via the resistor R1, and the relay R is turned on.
yt operates, contact am switches, current i+ flows, and motor 5 rotates forward. Further, when an output signal is output to 3b, contact br is switched in the same way, current it flows, and motor 5 rotates in reverse. With the above configuration, when the knob is operated, the motor rotates so that the output voltage of potentiometer 1 and the output voltage of potentiometer 2 are always equal, and the optical axis of the headlight can be adjusted.

However, in conventional optical axis adjustment devices like this, a potentiometer is used to detect the direction of the original axis and the voltage is compared, which has the problem of short durability of the potentiometer and large deterioration over time. This invention has been made by focusing on these conventional problems, and uses a variable inductance to detect the direction of the optical axis and uses a method to compare the pulses of the oscillation wave.
Therefore, it is an object of the present invention to solve the above problems.Hereinafter, the present invention will be explained based on the drawings.

FIG. 2 is a circuit diagram showing an embodiment of the present invention. First, to explain the configuration, 6 is a variable inductance, and the inductance automatically changes according to changes in the optical axis direction of the headlight. Reference numeral 7 denotes an oscillator, which is composed of an inverter circuit INV, 1, a resistor R1, and capacitors C+ and Ct. 8
is a waveform shaping circuit, and the inverter circuit INV, 2, I
Consists of NV, 3. 9 is a reference pulse circuit, which consists of a variable resistor VR, a capacitor Can, and a monostable multi, and the pulse of the monostable multi can be varied by operating the variable resistor vRtl. 10 is a comparison circuit. ,
Inverter circuit INV, 4 to 7, NOR circuit N0RI,
N0R2, D type flip 70 tube circuit D-FFI,
The D-FF2 compares the pulse of the reference pulse circuit with the output pulse of the waveform shaping circuit, and outputs the result. In other words, if the former is longer than the latter, D
- Output from FF2, if the latter is longer than the former, I/'
Output from iD-FFI.

4#'i In the motor drive circuit, the base resistor R,, R weight, the transistor TrI r Tr,, S'R'lIr R
h j t), and the flip-flop circuit D −F
When the output is output from FI, it is transmitted to the transistor T via the resistive island.
r is turned on, relay 17□ is activated, contact al is switched, current 11 flows through motor 5, and motor 5 is rotated forward (or reversed). In addition, flip Flora 1 circuit D-FF2
When the output is output from the transistor Trf via the resistive island
fi Zf on 1. , Relay Rh operates and contact b+
The switching motor 5 receives a current i! flows and reverses motor 5 (
or forward rotation).

Next, the operation of the optical axis driving device of the present invention having the above-described configuration will be explained.

When the variable resistor VR is operated to adjust the optical axis of the headlamp, the pulse of the monostable multi changes, and a difference occurs between the output pulse of the waveform shaping circuit 8 and the motor 5 to eliminate this difference. rotates to adjust the original axis and change the variable inductance. In other words, if you operate the variable resistor VR so that the output width of the monostable multi is increased as shown in Figure 3, the output width of INV, 3 and the monostable unit that turns on at the rising edge of the output pulse of INV, 3 will change. If you take the NOR between INV, which is the inverted signal of the stable multi output, and the output pulse of 4, you get N0R.
The output of D-FF1u INV, 3 (2) inverted signal terminal INV, 60 rises, the output is held, the base current flows through the resistor R + 'x, and the transistor T
r is turned on, relay RV+ is activated and contact l is switched, current t flows through motor 5 and it rotates forward, the optical axis drive device is activated, and as light a changes, the variable inductance changes. I'll go.

When both pulses become equal, the output signal of N0RI disappears and the outputs of fi and D-FFI are cleared, so the transistor Tr1 is turned off, the contact a returns to its original state, and the motor 5 stops.

If the variable resistor VR is operated in the opposite direction, the result will be as shown in FIG. That is, the inversion of the output signal of INV, 3, 4g
If you take the NOR between the output signal of INV, 5 and the output signal of the monostable multi, you will get the output of N0R2, which is the output signal of D-FF.
2 is INV, which is an inverted signal of the monostable multi output signal;
The output is held at the rising edge of the output signal of 7, and the output is held through the resistor R and the transistor +1. , the base current flows to turn on the relay Ry! operates, and the contact switches/changes.
At step 5, the current i flows and reverses, and the optical axis drive device operates to change the optical axis and the variable inductance changes, and when the pulses of both become equal, the motor stops.

FIG. 5 is a structural diagram showing an example of an optical axis driving device.

The plate is a headlamp, and 12a is a frame holding the headlamp HLt. This frame is rotatably supported around a shaft 12b, and the light of the headlamp HLt is changed by the rotation of the shaft. The axis changes upward or downward. 12c is a drive shaft disposed on the back side of the upper end of the frame 12a, and when the motor 5 rotates forward (or reversely), it extends to the left in the figure or is pulled in to the right through the IJIL mechanism 12d. It is configured as follows. 6a is a variable inductance whose inductance value changes as the ferrite core 6b attached to the drive shaft 12c moves in and out of the air core. That is, the rotation of the motor 5 moves the drive shaft 12c back and forth, and the frame body 1
When 2a rotates and the optical axis of the headlamp HL changes, the inductance value of the variable inductance 6a changes at the same time.

As described above, according to the present invention, when a variable inductance is used to detect the direction of the optical axis, the pulse width determined by the variable inductance value is compared with a reference pulse width that is set arbitrarily. Since it was made to adjust the nine glazes, the optical axis detection part is non-contact, which has the effect of improving durability.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a conventional optical axis adjustment device, Fig. 2 is a circuit diagram showing an example of the implementation of the present invention, and Figs. 3 and 4 are time charts for explaining the operation of the circuit shown in Fig. 2. , FIG. 5 is a sectional view taken along the line -fl of the mechanism section. 4...Motor drive circuit, 5...Motor, 6...Variable inductance 7...Oscillator, 8...Waveform shaping circuit, 9...1 reference pulse box, VR...Reference pulse Variable resistor for width adjustment, 10... Comparison circuit. Patent Applicant: Ichikoh Industries Co., Ltd. Agent, Patent Attorney: Tadashi Akimoto Figure 3 (IIJV button output (place number) -1-m-ri-f--)
-1 (Naka-Multi output signal - 1-cho-1-1-1-1-J--------1- (lNV, 4111 output signal) -shi-11-F-] -111''-(NORI/) outgoing issue) -[1-1111-J]-Figure 4 (INV, output of 3>-1 [-1]---J- 1-1
-(lNV, 5nouthE1.) -shi-m-[-1]
−−−"−〇−ψ−Fmulti n output Kai)−1"−−
1--111 "--l-1 (NOR2's output No. 1)-
m--"1-1--ft-Figure 5 1-b

Claims (1)

[Claims] an optical axis drive device that changes the direction 5 of the original axis of a headlamp of a vehicle according to the rotation of a motor; a variable inductance whose inductance changes in accordance with the direction of the optical axis of the headlamp;
An oscillator whose oscillation frequency changes as the variable inductance changes, a waveform shaping circuit that shapes the signal output from this oscillator into a pulse wave, and a waveform shaping circuit that is set according to the magnitude of the load applied to the vehicle. a reference pulse circuit that generates a single pulse with a width of 1. An optical axis adjustment device for a headlamp, comprising a motor drive circuit that rotates a motor forward or reverse.