JP2865566B2 - Vehicle headlight irradiation angle position adjustment device - Google Patents

Abstract

PURPOSE:To generate no misoperation, even electric power supply is taken from the nearest battery line and earth line into a drive unit part. CONSTITUTION:A constant current Ic with a value matching a set radiation angle position is outputted from a setting equipment 1-1 so as to be given to left/right front light drive units 2-1, 3-1. Assuming that the set radiation angle position is changed in a down direction and the output current Ic becomes small, in the drive unit 2-1, the voltage Vsp at a point P1 is dropped and the voltage Vo of a point P3 is also dropped following that. When Vo is a value of [(Bz/2)-alpha] or less, the output of CP2 becomes 'L' and a motor M is rotated reversely and the radiation angle position of the front light 4 is lowered. By the reverse rotation of the motor M, the voltage Vpv of a point P2 is raised and Vo is also raised following this. When Vo becomes [(Vz/2)-alpha] or more, the output of CP2 is returned back to 'H' level and the motor M is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular headlamp suitable for use in remotely adjusting the irradiation angle position of a headlamp held to be tiltable with respect to a vehicle body from a driver's seat side. The present invention relates to an irradiation angle position adjusting device.

[0002]

2. Description of the Related Art In a vehicle, especially an automobile, a large load is applied to a front wheel side or a rear wheel side of a vehicle body because a vehicle body and an axle are connected by a suspension device composed of a leaf spring, a coil spring or the like. The attitude of the vehicle body will be in the forward sunken or sunken state, which will change the vertical illumination angle of the headlamp with respect to the road surface and impair driving safety. If this happens, there is a danger that the driver of the oncoming vehicle will be significantly dazzled. In order to correct such a change in the irradiation angle of the headlight with respect to the road surface, the headlight is held so as to be tiltable with respect to the vehicle body, and the irradiation angle position of the headlight is remotely controlled from the driver's seat side. Various irradiation angle position adjusting devices configured to be adjustable by operation have been proposed.

FIG. 7 shows an example of such a case. In FIG.
Is an irradiation angle position setting device (variable resistor) disposed on the driver's seat side, 2 is a right headlight drive unit attached to a right headlight 4 held to be tiltable with respect to the vehicle body, 3 is a left headlight 5
It is a left headlight drive unit attached to. According to this irradiation angle position adjusting device, the irradiation angle positions of the headlights 4 and 5 can be automatically adjusted by operating the irradiation angle position setting device 1. That is, when the irradiation angle position setter 1 is operated to change the voltage (set voltage) Vsp at the divided voltage take-out point, the right headlight drive unit 2 and the left headlight are moved to positions corresponding to the set voltage Vsp. The drive unit 3 adjusts the irradiation angle positions of the right headlight 4 and the left headlight 5.

[0004]

However, according to such a conventional irradiation angle position adjusting device, the positions of the right headlight driving unit 2 and the left headlight driving unit 3 are set at a distance from the irradiation angle position setting device 1. Right headlight drive unit 2 and left headlight drive unit 3
Power is drawn from the nearest battery line and earth line to the right headlight drive unit 2
In addition, the power supply potential and the ground potential in the left headlight drive unit 3 are different from those in the irradiation angle position setting device 1, and the correspondence between the set irradiation angle position and the set voltage Vsp changes, which may cause a malfunction. There was.

In order to solve this, as shown in FIG. 8, the power supply voltage to the irradiation angle position setting device 1 is divided into a right headlight drive unit 2 and a left headlight drive unit 3 via a line L2. A method of connecting the grounds of the right headlight drive unit 2 and the left headlight drive unit 3 to the ground line of the irradiation angle position setting device 1 via the line L3 is conceivable. However, in such a method, the setting voltage Vs from the irradiation angle position setting device 1 is used.
In addition to the supply line L1 for p, lines L2 and L3 are required, which complicates wiring and increases costs. Also,
In order to match the potential difference in the irradiation angle position setting device 1 with the potential difference in the right headlight driving unit 2 and the left headlight driving unit 3, the irradiation angle position setting device 1 controls the right headlight driving unit 2 and the left headlight driving. In accordance with the distance to the unit 3 (depending on the type of vehicle), it is necessary to take measures such as inserting a resistor on the irradiation angle position setting device 1 side.

The present invention has been made in order to solve such a problem, and an object of the present invention is to draw power from a battery line and a ground line nearest to a headlight drive unit. Even if the power supply potential or the ground potential in the headlamp drive unit is different from that in the irradiation angle position setting unit, there is no risk of malfunction and there is no need to provide complicated wiring, and wiring of the vehicle body is eliminated. An object of the present invention is to provide an irradiation angle position adjusting device which can be simplified and the number of wiring lines can be reduced.

[0007]

In order to achieve such an object, in the first invention (the invention according to claim 1), the irradiation angle position setting section includes: an irradiation angle position setting section;
Current conversion means for converting the irradiation angle position set via the irradiation angle position setting means into a constant current having a value corresponding to the position and outputting the constant current. Further, the headlight driving unit unit detects the actual irradiation angle position of the headlight according to the signal conversion means for converting the output current from the current conversion means into a physical quantity corresponding to the current value, and according to the position. Irradiation angle position detecting means for converting to a physical quantity, comparing the physical quantity from the irradiation angle position detecting means with the physical quantity from the signal converting means,
An irradiation angle position adjusting means for adjusting the irradiation angle position of the headlight based on the comparison result.

[0008] In the second invention (the invention according to claim 2), the irradiation angle position setting unit includes an irradiation angle position setting unit and an irradiation angle position set via the irradiation angle position setting unit. Current conversion means for converting the current into a constant current having a value corresponding to the position and outputting the constant current. The headlight drive unit includes a signal conversion unit that converts an output current from the current conversion unit into a voltage Vsp corresponding to the current value;
A potentiometer produces a voltage Vpv in accordance with one end to the supply voltage V _B is the actual irradiation angle position to the reference voltage V _REF is applied the divided voltage drawing point headlamp at its other end, the voltage taken out from the potentiometer Vpv
And a voltage Vsp from the signal conversion means, and an irradiation angle position adjusting means for adjusting the irradiation angle position of the headlight based on the comparison result; a reference voltage V _REF applied to the other end of the potentiometer; Level drop detecting means for detecting an abnormal level drop of Vsp based on the voltage Vsp from the means.

The third invention (the invention according to claim 3) is the invention according to the first invention or the second invention, wherein a plurality of headlight drive units are provided, and an irradiation angle position on these headlight drive units is provided. The output current from the setting unit is generated in parallel by extracting the divided voltage generated at the divided voltage extraction point of the variable resistor constituting the irradiation angle position setting means in the irradiation angle position setting unit in parallel. It is.

[0010]

Therefore, according to the present invention, in the first invention, when the irradiation angle position of the headlight is set in the irradiation angle position setting section, a constant current having a value corresponding to the set irradiation angle position is output. You. This output current is supplied to the headlight drive unit. The headlight drive unit converts the output current from the irradiation angle position setting unit into a physical quantity (for example, voltage or magnetic force) corresponding to the current value, and converts the converted physical quantity and the actual irradiation angle position of the headlight. And adjusts the irradiation angle position of the headlight based on the comparison result.

In the second invention, when the irradiation angle position of the headlight is set in the irradiation angle position setting section, a constant current having a value corresponding to the set irradiation angle position is output. This output current is supplied to the headlight drive unit. The headlight drive unit converts the output current from the irradiation angle position setting unit into a voltage Vsp according to the current value,
The converted voltage Vsp is compared with the voltage Vpv extracted from the potentiometer, and the irradiation angle position of the headlight is adjusted based on the comparison result. Further, based on the reference voltage _VREF applied to the other end of the potentiometer and the voltage Vsp from the signal conversion means, an abnormal level drop of Vsp is detected. Further, in the third invention, the output current from the irradiation angle position setting unit to the plurality of headlight drive units is divided by the divided voltage generated at the divided voltage extraction point of the variable resistor constituting the irradiation angle position setting means. Voltages are taken out in parallel and generated individually.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. [Embodiment 1] FIG. 1 is a circuit diagram of an irradiation angle position adjusting apparatus showing an embodiment of the present invention. In FIG.
1 is an irradiation angle position setting device arranged on the driver's seat side, and 2-1.
A right headlight drive unit attached to the right headlight 4 held so as to be tiltable with respect to the vehicle body, and 3-1 is a left headlight drive unit attached to the left headlight 5.

In this embodiment, the irradiation angle position setting device 1
-1 indicates a variable resistor RV1, resistors Ra and Rb, and PN
It has a P transistor Q1, resistors R1 and R2, a Zener diode ZD1, and a diode D1. The right headlight drive unit 2-1 includes resistors R3 to R9.
, A variable resistor (potentiometer) RV2, a Zener diode ZD2, a capacitor C1, diodes D2 to D4, comparators CP1 and CP2, relays R _y1 and R _y2, and a motor M. The left headlight drive unit 3-1 has the same configuration as the right headlight drive unit 2-1.

In the right headlamp drive unit 2-1, the resistors R4 and R5 have the same resistance value, the resistors R4 and R5 are connected in series, and one end of the resistor R4 is connected to the resistor R3 and the transistor Q1. The other end of the resistor R5 is connected to a divided voltage extraction point P2 of the variable resistor RV2. The voltage Vpv generated at the divided voltage extraction point P2 of the variable resistor RV2 is the motor M
It changes according to the rotation angle position of. Further, the irradiation angle position of the headlight 4 is increased by the forward rotation of the motor M, and is decreased by the reverse rotation.

When the voltage between the anode and the cathode of the Zener diode ZD2 is Vz, the resistors R6 to R8
, And a comparison reference voltage of [(Vz / 2) + α (α ≒ 0)] is applied to the non-inverting input of the comparator CP1, and [(Vz /
2) -α]. Further, when the actual irradiation angle position of the headlight 4 matches the irradiation angle position set by the irradiation angle position setting device 1-1, the voltage Vsp at the point P1 and the voltage Vpv at the point P2.
And the voltage Vo generated at the connection point P3 between the resistors R4 and R5 becomes [(Vz / 2) -α] <Vo <[(V
z / 2) + α].

Next, the operation of the irradiation angle position adjusting device thus constructed will be described by taking the right headlight 4 as a representative. Now, it is assumed that the actual irradiation angle position of the right headlight 4 matches the irradiation angle position set by the irradiation angle position setting device 1-1. In this case, the connection point P between the resistors R4 and R5
3 is [(Vz / 2) -α] <Vo <
Since it is within the range of [(Vz / 2) + α],
The comparison outputs of the comparators CP1 and CP2 maintain the “H” level state. Therefore, the energization of the relays R _y1 and R _y2 is not performed, and the movable contacts S ₁ and R _{1 of} the relays R _y1 and R _y2 are not _activated .
Since both S2 are connected to the fixed contacts S1a and S2a, the motor M maintains the stopped state.

In such a state, when the irradiation angle position setting device 1-1 is operated to change the point of extraction (set irradiation angle position) of the divided voltage from the variable resistor RV1, that is, between the base and the emitter of the transistor Q1, changing the voltage V _BE1, constant base current I _B1 corresponding to the voltage V _BE1 between the base emitter flows. As a result, the collector current I h _FE times the base current I _B1 is applied to the transistor Q1.
c flows, and the voltage drop V _R1 across the resistor R1 is controlled to be constant. This voltage drop _VR1 does not change even if the power supply voltage to the irradiation angle position setting device 1-1 changes. That is, from the irradiation angle position setting device 1-1, the irradiation angle position setting device 1-1.
A constant current Ic (Ic = V _R1 / R1) determined only by the set irradiation angle position without depending on the power supply voltage to the power supply is output.

The output current Ic from the irradiation angle position setting unit 1-1 is divided into て, and the right headlight drive unit 2-1
Given to. In the right headlight drive unit 2-1, the voltage Vsp at the connection point P1 changes according to the output current Ic from the irradiation angle position setting device 1-1. Here, if it is assumed that the setting of the irradiation angle position in the irradiation angle position setting device 1-1 has been changed in the down direction, the output current Ic from the irradiation angle position setting device 1-1 becomes small. , The voltage Vo generated at the connection point P3 also decreases. When the voltage Vo generated at the connection point P3 decreases and becomes a value corresponding to the set irradiation angle position of [(Vz / 2) -α] or less, the comparison output of the comparator CP2 becomes the “L” level, The relay _Ry2 is energized and energized.
By energizing energizing of the relay R _y2, the movable contact S2 of the relay R _y2 is connected to the fixed contact point S2b side, the current flows in the shown direction A to the motor M, the motor M is reversely rotated, the headlamp 4 The irradiation angle position starts to decrease.

When the motor M rotates in the reverse direction, the variable resistor RV
2, the voltage Vpv generated at the divided voltage extraction point P2 increases, and the voltage Vo generated at the connection point P3 starts to increase accordingly. When the voltage Vo generated at the connection point P3 becomes equal to or higher than [(Vz / 2) -α], the comparator CP
2 returns to the “H” level, the energization of the relay R _y2 is released, the movable contact S2 of the relay R _y2 is connected to the fixed contact S2a, and the motor M stops. As a result, the irradiation angle position of the right headlamp 4 coincides with the set irradiation angle position after being changed by the irradiation angle position setting device 1-1.

When the irradiation angle position set by the irradiation angle position setting device 1-1 is changed in the upward direction, the output current Ic from the irradiation angle position setting device 1-1 becomes large, so that the connection point P1 Rises, and the voltage Vo generated at the connection point P3 accordingly rises. When the voltage Vo generated at the connection point P3 increases to a value corresponding to the set irradiation angle position equal to or more than ((Vz / 2) + α), the comparison output of the comparator CP1 becomes “L” level, and the relay R _y1
Is energized. By energizing the relay R _y1 ,
Movable contacts S1 of the relay R _y1 is connected to the fixed contact point S1b side, and current flows in the illustrated direction B to the motor M, the motor M
Rotates forward, and the irradiation angle position of the headlight 4 starts to increase.

When the motor M rotates forward, the variable resistor RV
2, the voltage Vpv generated at the divided voltage take-out point P2 decreases, and the voltage Vo generated at the connection point P3 starts to decrease accordingly. When the voltage Vo generated at the connection point P3 becomes equal to or less than [(Vz / 2) + α], the comparator CP
1 returns to the “H” level, the energization of the relay R _y1 is released, the movable contact S1 of the relay R _y1 is connected to the fixed contact S1a, and the motor M stops. As a result, the irradiation angle position of the right headlamp 4 coincides with the set irradiation angle position after being changed by the irradiation angle position setting device 1-1.

Attention is now paid to the voltage Vsp at the connection point P1 in the right headlamp drive unit 2-1. The voltage Vsp depends on the output current Ic from the irradiation angle position setting device 1-1. Change. That is, even if the power supply potential and the ground potential in the right headlight drive unit 2 are different from those in the irradiation angle position setting device 1-1, the output current Ic from the irradiation angle position setting device 1-1 and the setting irradiation angle The correspondence with the position does not change, and the voltage Vsp at the connection point P1 changes according to the output current Ic that does not change.

For this reason, even if power is drawn into the right headlight drive unit 2-1 and the left headlight drive unit 3-1 from the nearest battery line and ground line, that is, wiring as shown in FIG. However, there is no risk of malfunction. That is, in the irradiation angle position adjusting device according to the present embodiment, there is no possibility that a malfunction occurs even if wiring similar to that shown in FIG. 7 is performed. Therefore, it is not necessary to provide complicated wiring as shown in FIG. Body wiring is simplified, and the number of wiring lines is reduced.

In the first embodiment, the current Ic output from the irradiation angle position setting device 1-1 is divided by 1 /
It is assumed to provide shunts to 2 to right headlamp drive unit 2-1 and the left headlamp drive unit 3-1, as an irradiation angle locator 1-2 as shown in FIG. 3, the current I _c1,
The I _c2 lines L1-1, or as providing the right headlamp drive unit 2-1 and the left headlamp drive unit 3-1 through L1-2. In this case, the voltage between the base and the emitter of the transistors Q1 and Q3 is temperature-compensated by the transistor Q2. That is, when the temperature increases, the voltage V _BE2 between the base and the emitter of the transistor Q2 decreases, I2 increases, and the potential at the point P4 increases. The voltages V _BE1 and V between the base and the emitter of the transistors Q1 and Q3
If _BE3 is to have the same temperature characteristics as V _BE2, V _BE1,
V _BE3 also becomes smaller by the same voltage as V _BE2 ,
The voltages at the six points are unchanged.

In the first embodiment, the relays R _y1 and R _y2 are used to drive the motor M. However, a motor driver IC, a bridge circuit of a transistor, or the like may be used. Further, a high-output operational amplifier may be used instead of the comparators CP1 and CP2, and the motor M may be directly driven by the output of the operational amplifier.

[Embodiment 2] FIG. 4 is a circuit diagram of an irradiation angle position adjusting apparatus showing another embodiment (Embodiment 2) of the present invention. In this embodiment, the irradiation angle position setting device 1-3 is used.
In addition, a variable coil CL1 whose inductance changes as the magnetic core moves is used. That is, in the irradiation angle position setting device 1-3, a frequency corresponding to the inductance of the variable coil L1 is obtained from the oscillation circuit 1-31, and this frequency is converted into a voltage value by the F / V converter 1-32. This voltage value is applied to transistors Q1 ', Q
The constant currents _Ic1 and _Ic2 are converted to constant currents _Ic1 and _Ic2 via the 2 'and Q3', and the right headlight drive unit 2-2 and the left headlight drive unit 3-
2 to flow through.

The right headlight drive unit 2-2 and the left headlight drive unit 3-2 correspond to the right headlight drive unit 2-1 and the left headlight drive unit 3--2 described with reference to FIG.
1, but a motor driver 2-21 is used in place of the relays _Ry1 and _Ry2 . In the irradiation angle position adjusting device, the use of the variable coil CL1 whose inductance is changed by the movement of the magnetic core allows the irradiation angle position to be set in a non-contact manner when used for auto-leveling, thereby improving durability. ,It is valid.

[Embodiment 3] FIG. 5 is a circuit diagram of an irradiation angle position adjusting apparatus showing another embodiment (Embodiment 3) of the present invention. In this embodiment, the output currents I _c1 and I _c2 from the irradiation angle position setting device 1-2 are converted to the right headlight drive unit 2-
3. The output currents I _c1 and I _c2 are given to the left headlight drive unit 3-3, and are converted into magnetic force in the right headlight drive unit 2-3 and the left headlight drive unit 3-3.

That is, in the description of the right headlight drive unit 2-3, the output current _Ic1 from the irradiation angle position setting device 1-2 is supplied to the coil CL2 wound around the core 2-31, and At 31, a magnetic force corresponding to I _c1 is generated. On the other hand, the actual rotation angle position of the motor M, that is, the right headlight 4
Is detected by the position detection means 2-32, and a current Ipv corresponding to the detected irradiation angle position is obtained from the current conversion means 2-33. Then, the current conversion means 2-33
Current Ipv from the coil C wound around the core 2-31
L3 to generate a magnetic force corresponding to Ipv in the core 2-31. Magnetic force and I according to I _c1 generated in core 2-31
The magnetic force according to pv acts in a direction to cancel each other out, and the difference of this magnetic force is detected by the Hall element 2-34. The difference in the magnetic force detected by the Hall element 2-34 is determined by the motor driver 2-3.
35. The motor driver 2-35 drives the motor M so that the difference between the magnetic forces detected by the Hall element 2-34 becomes zero.

[Embodiment 4] FIG. 6 is a circuit diagram of an irradiation angle position adjusting apparatus showing another embodiment (Embodiment 4) of the present invention. In this embodiment, the irradiation angle position setting device 1-
4 is a variable resistor RV1, resistors R12 to R16, P
NP transistors Q1 and Q3 and NPN transistor Q
2, Q4, a Zener diode ZD1, diodes D1 and D2, and a lamp LP. The right headlight drive unit 2-4 includes resistors R17 to R30, a potentiometer RV2, a varistor ZNR1, capacitors C2 to C7, a Zener diode ZD3, a diode D5, a NAND gate NAND1, a comparator CP1 to CP6, , A reference voltage circuit 2-41, a control logic 2-42, a constant voltage circuit 2-43, a motor driver 2-44, a motor lock detection circuit 2-45, and a motor M. The left headlight drive unit 3-4 has the same configuration as the right headlight drive unit 2-4.

In the irradiation angle position setting device 1-4, the emitter of the transistor Q1 is connected to the base of the transistor Q2, and the divided voltage extraction point P0 of the variable resistor RV1 is connected to the base of the transistor Q1. Further, the emitter of the transistor Q3 is connected to the base of the transistor Q4, and the variable resistor RV is connected to the base of the transistor Q3.
One divided voltage take-out point P0 is connected. That is, in the irradiation angle position setting device 1-4, the variable resistor RV1
Is applied in parallel to the bases of transistors Q1 and Q3, and constant currents I _c1 and I _c2 corresponding to the divided voltages (set irradiation angles).
Is generated and flows in the headlight drive units 2-4 and 3-4 through the lines L1-1 and L1-2 via the transistors Q2 and Q4.

In the right headlight drive unit 2-4, the level drop detection circuit 2-
46 are constructed, and a level rise detection circuit 2-47 is constructed using the comparator CP6 as a component. Also,
The lowest voltage detection circuit 2-48 is constructed using the comparator CP3 as a component, and the highest voltage detection circuit 2-49 is configured using the comparator CP4 as a component.

In the right headlight drive unit 2-4,
The power supply voltage + V _B is applied to one end of the potentiometer RV2, and the reference voltage V _REF (+6 V) generated by the reference voltage circuit 2-41 is applied to the other end of the potentiometer RV2. Further, the reference voltage V _REF applied to the other end of the potentiometer RV2 is supplied to the inverting input of the comparator CP5 in the level drop detection circuit 2-46 by the comparison reference voltage VT.
H1 is set. The connection point P1 between the resistor R19 and the capacitor C5 is connected to the non-inverting input of the comparator CP5.
Is applied. The set voltage Vsp generated at the connection point P1 is also applied to the inverting input of the comparator CP6 in the level rise detection circuit 2-47, and the divided voltage of the resistors R29 and R30 is applied to the non-inverting input of the comparator CP6. It is set as VTH2.

The reference voltage V _REF generated by the reference voltage circuit 2-41 is applied to the inverting input of the comparator CP3 in the lowest voltage detecting circuit 2-48 and the non-inverting input of the comparator CP4 in the highest voltage detecting circuit 2-49. They are set as comparison reference voltages VTH3 and VTH4. Further, the divided voltage of the resistors R25 and R26 is applied to the non-inverting input of the comparator CP3 in the lowest voltage detection circuit 2-48. Also, the maximum voltage detection circuit 2-
The divided voltage of the resistors R27 and R28 is applied to the inverting input of the comparator CP4 at 49. The motor lock detection circuit 2-45 includes a timer circuit (not shown), and when the energization time of the motor M continues for a predetermined time or more, the motor locks (the motor M is turned on even though the voltage is applied). As a result, it functions to send an “L” level signal to the NAND gate NAND1.

[Defects in Embodiment 1] Embodiment 1 (FIG. 1)
In the irradiation angle position adjusting device shown in (1), the power supply voltage + Vz is applied to one end of the potentiometer RV2 in the headlamp drive unit 2-1, but the other end is grounded. For this reason, whether the voltage Vsp at the point P1 has become 0 potential due to the setting of the irradiation angle position setting device 1-1 (it may occur at the end of the range depending on the setting), or the 0 potential due to a short circuit to the ground line at point A It is not possible to determine whether or not the point A is short-circuited to the ground line, and the setting of the irradiation angle position setting unit 1-1 is incorrect, and the irradiation angle position of the headlight 4 is set to a different position from the setting. It may be fixed.

[Defects in the First Embodiment] In the first embodiment, for example, when the wire is disconnected at the point A and short-circuited to the ground line or contacted with the positive side of the battery, the headlight drive unit 2- Both 1 and 3-1 get stuck,
I don't know which one is out of order. Further, even if the irradiation angle position setting device 1-1 is changed to the irradiation angle position setting device 1-2 as shown in FIG. 3, a similar problem occurs. For example, it is assumed that the line L1-2 is disconnected at the point B and is open or contacts the positive side of the battery. In this case, the transistor Q3 is turned off, and the current flowing between the base and the emitter of the transistor Q3 increases the base potential of the transistor Q1. Thereby, the transistor Q1
Is turned off, the current _Ic1 to the right headlight drive unit 2-1 is cut off, and both the headlight drive units 2-1 and 3-1 do not operate.

When the line L1-2 is short-circuited to the ground line at the point B, the transistor Q3 is not turned off, and the right headlight drive unit 2-1 operates normally. In automobiles, it is overwhelmingly short-circuited to the earth line. In this case, even if one stops moving, the other moves, so that safety is ensured and it is also known which one has failed. Therefore, practically, there is not much problem. However, as described above, when the line L1-2 is open or comes into contact with the positive side of the battery, both the headlight drive units 2-1 and 3-1 do not operate. In such a case, the right headlight drive unit 2-
1 is expected to operate normally.

On the other hand, the irradiation angle position adjusting device shown in FIG. 6 overcomes the drawbacks of the first embodiment as follows. [Overcoming the Defects] In FIG. 6, assume that the line L1-1 is short-circuited to the earth line at the point A. In this case, the set voltage Vsp generated at the point P1 becomes 0 potential.
This set voltage Vsp is applied to the inverting input of comparator CP5 of level drop detection circuit 2-46. The reference voltage V _REF is supplied to the non-inverting input of the comparator CP5 as the comparison reference voltage VTH1. As a result, the comparator CP5 detects the level drop of the set voltage Vsp, and sets the comparison output to the “L” level. The "L" level comparison output from comparator CP5 is applied to NAND gate NAND1. In response to this, the output of the NAND gate NAND1 becomes "H" level, the control operation of the control logic 2-42 is latched, and the irradiation angle position of the headlight 4 is fixed at the current setting irradiation angle position.

On the other hand, in FIG. 6, it is assumed that the operation at the irradiation angle position setting device 1-4 sets the voltage Vsp at the point P1 to the lowest voltage that can occur at the end of the range. Minimum value in this case, set voltage Vsp is the lowest value of the voltage Vpv generated in the divided voltage drawing point P2 of the potentiometer RV2, i.e. equal to the reference voltage V _REF applied to the other end of the potentiometer RV. That is,
By operations in the irradiation angle locator 1-4 does not become lower than the set voltage Vsp is the reference voltage V _REF. Therefore, the short-circuit to the ground line at the point A is not mistaken for the setting by the irradiation angle position setting device 1-4, and the short-circuit to the ground line at the point A is reliably detected and the headlight 4 is detected.
Can be fixed to the currently set irradiation angle position. In this embodiment, the potentiometer R
The reference voltage V _REF applied to the other end of V2 is set as the comparison reference voltage VTH1.
It may be set to be lower than _{RE F.}

[Overcoming the Defects] In FIG.
It is assumed that 1-2 is disconnected at point B, short-circuited to the ground line, or contacted with the positive side of the battery. In this case, even if the transistors Q3 and Q4 are turned off, the potential of the variable resistor RV1 with respect to the divided voltage extraction point P0 is not affected, so that the transistors Q1 and Q2 are not turned off, and the right headlight drive is not performed. Unit 2-1 operates normally. In other words, in this embodiment, if one of the members stops moving due to the disconnection, the other member moves regardless of the disconnection state, so that safety is ensured, and it is also known which one has failed, and there is no practical problem. Does not occur.

In this embodiment, when the set voltage Vsp exceeds the comparison reference voltage VTH2 in the level rise detection circuit 2-47 due to some abnormality, the comparison output of the comparator CP6 becomes "L" level and the NAND gate The output of NAND1 becomes "H" level, the control operation in the control logic 2-42 is latched, and the irradiation angle position of the headlight 4 is fixed at the current setting irradiation angle position. Also, when the power supply voltage + V _B decreases abnormally, the divided voltage between resistors R25 and R26 is smaller than the comparison reference voltage VTH3 at the lowest voltage detection circuit 2-48, the comparison output of the comparator CP3 is "L" Level, the output of the NAND gate NAND1 becomes “H” level, the control operation in the control logic 2-42 is latched, and the headlight 4
Is fixed to the currently set irradiation angle position.

When the power supply voltage + V _B rises abnormally, the divided voltage of the resistors R27 and R28 becomes higher than the comparison reference voltage VTH4 in the maximum voltage detection circuit 2-49, and the comparison output of the comparator CP4 becomes higher. The output level of the NAND gate NAND1 changes to the "L" level, the output of the NAND gate NAND1 changes to the "H" level, the control operation of the control logic 2-42 is latched, and the irradiation angle position of the headlight 4 is fixed at the current setting irradiation angle position. You. When the energization time of the motor M continues for a predetermined time or more, the motor lock detection circuit 2-48 sends an "L" level signal to the NAND gate NAND1 assuming that the motor is locked, and outputs the signal from the NAND gate NAND1. The output becomes “H” level, the control operation in the control logic 2-42 is latched, and the power supply to the motor M is cut off.

[0043]

As apparent from the above description, according to the present invention (first to third inventions), the irradiation angle position setting unit outputs a constant current having a value corresponding to the set irradiation angle position. Therefore, even when the power is drawn from the nearest battery line and the ground line to the headlight drive unit, the power supply potential and the ground potential at the headlight drive unit are different from those at the irradiation angle position setting unit. Even if it is, the correspondence between the set irradiation angle position and the output current does not change, no malfunction occurs, the complicated wiring is unnecessary, the body wiring is simplified, and the number of wiring lines is reduced. It can be reduced. Further, in the second invention, since so as to detect abnormal levels decrease in Vsp on the basis of the voltage Vsp from the reference voltage V _{RE F} and the signal conversion means is applied to the other end of the potentiometer, to the effect In addition, it is possible to prevent a short circuit to the ground line from being mistaken for the setting in the irradiation angle position setting unit.

According to the third aspect of the invention, the output current from the irradiation angle position setting unit to the plurality of headlamp drive unit units is set at the divided voltage extraction point of the variable resistor constituting the irradiation angle position setting means. Since the generated divided voltages are taken out in parallel and generated individually, for example, in addition to the above-mentioned effects, for example, when the headlamp drive unit is composed of two, a right headlamp drive unit and a left headlamp drive unit, If one of them becomes stuck due to a disconnection, make the other move regardless of the disconnection condition to ensure safety and to know which one is malfunctioning so that there is no practical problem. It is possible to do.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of an irradiation angle position adjusting device showing one embodiment (embodiment 1) of the present invention.

FIG. 2 is a diagram showing a wiring state of the irradiation angle position adjusting device.

FIG. 3 is a circuit diagram showing another example of an irradiation angle position setting device in the irradiation angle position adjusting device.

FIG. 4 is a circuit configuration diagram of an irradiation angle position adjusting device showing another embodiment (Embodiment 2) of the present invention.

FIG. 5 is a circuit configuration diagram of an irradiation angle position adjusting device showing another embodiment (Embodiment 3) of the present invention.

FIG. 6 is a circuit configuration diagram of an irradiation angle position adjusting device showing another embodiment (Embodiment 4) of the present invention.

FIG. 7 is a diagram showing a wiring state of a conventional irradiation angle position adjusting device.

8 is a diagram showing a wiring state of the irradiation angle position adjusting device which can be considered for the purpose of preventing malfunction of the irradiation angle position adjusting device shown in FIG. 7;

[Explanation of symbols]

1-1: Irradiation angle position setting device, 2-1: Right headlight drive unit, 3-1: Left headlight drive unit, RV1: Variable resistor, Q1: PNP transistor, RV2: Variable resistor (potentiometer), M: Motor, ZD1, ZD2
... Zener diode, R3-R8 ... Resistance, CP1, C
P2 ... Comparator, _Ry1 , _Ry2 ... Relay, 2-46 ...
Level drop detection circuit.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shinji Teraoka 500 Kitawaki, Shimizu-shi, Shizuoka Prefecture Koito Manufacturing Co., Ltd. Shizuoka Plant (56) References JP-A-59-195440 (JP, A) JP-A-5959 -118542 (JP, A) JP-A-5-85256 (JP, A) JP-A-5-24474 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60Q 1/076

Claims (3)

(57) [Claims] 1. An irradiation angle position setting means, and a current conversion means for converting an irradiation angle position set via the irradiation angle position setting means into a constant current having a value corresponding to the position and outputting the constant current. An irradiation angle position setting unit, a signal conversion unit that converts an output current from the current conversion unit into a physical quantity corresponding to the current value, and detects an actual irradiation angle position of the headlight and responds to the position. Irradiation angle position detecting means for converting the physical quantity from the irradiation angle position detecting means and the physical quantity from the signal converting means, and adjusting the irradiation angle position of the headlight based on the comparison result. An irradiation angle position adjusting device for a vehicle headlight, comprising: a headlight driving unit having irradiation angle position adjusting means. 2. An irradiation angle position setting means, and a current conversion means for converting an irradiation angle position set via the irradiation angle position setting means into a constant current having a value corresponding to the position and outputting the constant current. and irradiation angle position setting unit comprising Te, a signal conversion means for converting the output current from said current converting means into a voltage Vsp corresponding to the current value, the power supply voltage V _B on the one end is the reference voltage V _REF at the other end A potentiometer that generates a voltage Vpv corresponding to the actual irradiation angle position of the headlight at the applied voltage division point, and compares a voltage Vpv extracted from the potentiometer with a voltage Vsp from the signal conversion unit, and irradiation angle position adjusting means for adjusting the irradiation angle position of the headlight based on the comparison result, the reference voltage V _REF and the signal conversion means is applied to the other end of the potentiometer La voltage Vsp
A headlamp drive unit comprising: a headlamp drive unit for detecting an abnormal decrease in the level of Vsp on the basis of the above. 3. The headlamp driving unit according to claim 1, wherein a plurality of headlamp driving units are provided, and an output current from the irradiation angle position setting unit to the headlamp driving unit is set to the irradiation angle position setting. Wherein the divided voltage generated at the divided voltage take-out point of the variable resistor constituting the irradiation angle position setting means in the section is taken out in parallel to generate each divided voltage, and the irradiation angle position of the vehicular headlamp is produced. Adjustment device.