JPH0579538B2 - - Google Patents

Abstract

PURPOSE:To improve safety and reliability by restoring the lighting direction of a lighting means to a forward direction by outputting a prescribed restoration signal when a control signal having a pulse width corresponding to the steering angle of a steering wheel is not inputted after the completion of a prescribed cycle. CONSTITUTION:The steering state of a steering wheel is detected by the detecting means 1 and 2, and the detection signal is inputted into a control signal generating circuit 3. The control signal supplied from the control signal generating circuit 3 is outputted into a motor control circuit 4, and an electric motor 46 is driven to change the lighting direction of the head lamps. In this case, a fail-safe circuit 4A and a servomotor control circuit 48 are installed in the motor control circuit 4. A plurality of AND gates AND1 and AND2. OR gate OR1 and others are installed in the fail-safe circuit 4A, and an electric signal (restoration signal) having a prescribed pulse form is inputted into the AND gate AND2 from an oscillator OS.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cornering lamp system for a vehicle that changes the irradiation direction of a lighting means in conjunction with steering wheel steering.

[Conventional technology]

Vehicles, especially automobiles, are equipped with headlights to illuminate the road ahead at night, but these headlights illuminate only the front of the vehicle in a fixed manner; When the vehicle is approaching, the direction in which the vehicle is traveling cannot be sufficiently illuminated. In other words, when cornering or the like, the vehicle is not sufficiently illuminated in the direction in which the vehicle is actually traveling, which may pose a danger.

In order to solve this problem, cornering lamp systems have recently been proposed in which the direction of illumination of the headlights is varied in conjunction with the steering of the vehicle's steering wheel so that the direction of travel is illuminated.

[Problem that the invention seeks to solve]

However, conventionally proposed cornering lamp systems mechanically connect the steering wheel steering mechanism and the irradiation direction variable mechanism to make the irradiation direction of the headlights follow the steering angle steplessly (linearly). ) They are often mechanically configured to be variable, which not only complicates the overall system structure, but also requires special design depending on the vehicle type. In addition, since the steering wheel steering mechanism and the irradiation direction variable mechanism are mechanically connected, the irradiation direction of the headlights can be varied regardless of whether it is day or night.
This would impede durability.

[Means for solving problems]

The present invention has been made in view of these problems, and it is designed to periodically generate a control signal with a pulse width that corresponds to the steering angle, and to control the actual operation of the lighting means based on the generated control signal. The positional deviation between the irradiation direction of the lamp and the target irradiation direction determined in association with the steering angle is detected, and the irradiation direction of the lighting means is varied by driving an electric motor to make this detected positional deviation zero. In addition, if the control signal is not input even after a predetermined period, a return signal is sent in place of the control signal, and the irradiation direction of the lighting means is forcibly returned to approximately the front direction. It is designed to be fixed.

[Effect]

Therefore, according to the present invention, it is possible to linearly vary the irradiation direction of the lighting means by following the steering angle by using the electric motor, and the control signal is not input even if it exceeds a predetermined period. In an unexpected situation, the irradiation direction of the lighting means is forcibly returned to the substantially front direction and becomes fixed.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The vehicle cornering lamp system according to the present invention will be explained in detail below. FIG. 1 is a block diagram showing an embodiment of this cornering lamp system. In the figure, 1 is a rotating disk that rotates in conjunction with the steering of the steering wheel, and 2 is a photo sensor having two pairs of light emitting elements and light receiving elements (not shown). The rotating disk 1 is configured to rotate to the right in the figure when the handle is steered to the right, and to the left when the handle is steered to the left. A plurality of slits 1a of the same shape are formed at equal angular intervals on the outer peripheral flange surface of the rotating disk 1, and a light emitting element and a light receiving element of the photo sensor 2 are disposed facing each other at the passing positions of the slits 1a. , a photo interrupter including a first light emitting element and a light receiving element, and a photo interrupter including a second light emitting element and a light receiving element are arranged adjacent to each other in the photo sensor 2. Then, as the rotating disk 1 rotates clockwise or counterclockwise and passes through the slit 1a, a pulsed electrical signal having the same waveform but with a phase shift of approximately 90° is generated in the first and second photointerrupters. This pulsed electric signal is input to the rotation direction determining circuit 31 in the control signal generating circuit 3 via the terminals 3a and 3b.

The rotation direction determination circuit 31 has terminals 3a and 3b.
The direction of rotation of the rotary disk 1, that is, the steering direction of the steering wheel is determined based on the phase of the pulsed electric signal inputted through the . The UP signal and the DOWN signal sent from the output terminals 31a and 31b of the rotation direction determination circuit 31 are configured to transmit UP/DOWN signals.
It is designed to be input to the DOWN counter 32. The UP/DOWN counter 32 counts up or down its internal count value by the number of input UP signals or DOWN signals, and the voltage value corresponding to the count value in the UP/DOWN counter 32 is
Comparator 34 via D/A converter 33
It is designed to be set to the inverted input terminal of . A triangular wave reference voltage with a period of 20 msec is set at the non-inverting input terminal of the comparator 34 via a triangular wave generator 35.

The voltage value set to the inverting input terminal of the comparator 34 via the D/A converter 33 is
When the count value in the DOWN counter 32 is zero (when the steering wheel is in the straight steering position), the position is at the center of the vertical width of the triangular wave reference voltage set to the non-inverting input terminal of the comparator 34 via the triangular wave generator 35. Therefore, the control signal sent from the output terminal of the comparator 34 at this time becomes a periodic pulse signal with a duty ratio of 50%. Then, as the count value in the UP/DOWN counter 32 goes up or down, the set voltage value to the inverting input terminal of the comparator 34 decreases or increases in the D/A converter 33 in accordance with the up or down count value. I'm starting to do that. That is,
When the steering wheel is rotated clockwise or counterclockwise from the straight-ahead steering position, the duty ratio of the control signal sent from the output terminal of the comparator 34 is 50%.
It begins to increase or decrease starting from . That is, the pulse width of the control signal periodically sent out from the output terminal of the comparator 34 becomes variable according to the steering angle, and becomes wider when steering to the right and narrower when steering to the left. . and,
A control signal sent from the output terminal of this comparator 34 (output terminal 3c of the control signal generation circuit 3) is transmitted to the motor control circuit 4 via its input terminal 4a.
is now being entered.

The motor control circuit 4 includes a fail-safe circuit 4A that serves as an input section for control signals inputted through a terminal 4a, and a servo motor control circuit 4B that receives the output of the fail-safe 4A as an input. The fail-safe circuit 4A includes a resistor R0, one end of which is connected to a high potential power supply, and a resistor R0.
0 and input terminal 4a, and this inverter INV.
If the input signal is not inverted for a predetermined period (in this example, 40 msec), its Q output and Q bar output are set to "L" and "H". '' level, an AND gate AND1 whose input is the Q output of this retriggerable one shot RT, and an AND gate whose input is the Q bar output of this retriggerable one shot RT.
AND2, and an OR gate OR1 which receives the output of AND1 and the output of AND2 as inputs, and the potential generated at the connection point between resistor R0 and input terminal 4a is input to the other end of the input side of AND1. Also, the other end of the input side of AND2 has a 20 msec cycle sent by the oscillator OS and
A pulsed electrical signal (return signal) with a duty ratio of 50% is input.

The servo motor control circuit 4B includes a positional deviation detection circuit 41 which receives the output signal from the OR gate OR1 in the fail-safe circuit 4A, a motor drive time calculation circuit 42 which receives the output of this positional deviation detection circuit 41, and a rotation direction determination circuit. circuit 43, and an AND gate circuit 4 whose inputs are the outputs of the motor drive time calculation circuit 42 and rotation direction determination circuit 43.
4, and a motor driver 45 that drives the electric motor 46 according to the output of the AND gate circuit 44.
and a potentiometer 47 whose output voltage is varied according to the rotational angular position of the electric motor 46. The servo motor control circuit 4 is configured such that the irradiation direction of a headlamp 5 (FIG. 2) provided in the vehicle can be varied by the rotational driving force of the electric motor 46 in the servo motor control circuit 4. That is, by supplying a current in the direction of arrow A to the electric motor 46, the output shaft of the motor (46a shown in FIG. 3) rotates clockwise.
By driving the crank gear 46b and worm gear 46c, the sub-reflector 5b rotatably provided on the back of the lamp 5a (Fig. 2) is rotated, and the irradiation direction of the headlamp 5 is directed to the right when viewed from the driver's seat side. It is becoming variable. Furthermore, by supplying current to the electric motor 46 in the direction of arrow B in the figure,
The output shaft 46a rotates counterclockwise, drives the crank gear 46b and the worm gear 46c, rotates the sub-reflector 5b, and changes the irradiation direction of the headlight 5 to the left when viewed from the driver's seat. ing.

A deceleration drive mechanism 51 is constructed by mechanically coupling a crank gear 46b and a worm gear 46c to the output shaft 46a of the electric motor 46, and this deceleration drive mechanism 51 is built into the back side of the headlamp 5.
The rotational force of this deceleration drive mechanism 51 is transmitted through a link 52 to swing the sub-reflector 5b to the right or left. Furthermore, when the electric motor 46 is not driven, the sub-reflector 5b is forcibly returned to its rotational center position by the "zero" mechanism 53 mechanically connected to the link 52, and the headlight 5 is turned off. Direction of irradiation to the front of the vehicle (front direction)
It is configured to be held and fixed to. Note that a potentiometer 47 is attached to the deceleration drive mechanism 51.
is installed, and this potentiometer 4
7, the positional deviation detection circuit 41, motor drive time calculation circuit 42, and rotation direction determination circuit 4
3. AND gate circuit 44 and motor driver 4
A servo motor control board 48 formed with 5 is disposed.

FIG. 4 is a circuit configuration diagram specifically showing the internal configurations of the positional deviation detection circuit 41, motor drive time calculation circuit 42, and rotation direction determination circuit 43 in the servo motor control circuit 4B. In other words, the positional deviation detection circuit 41 has a NOR gate 41
a, 41b, inverters 41c, 41d, negative logic input AND gates 41e, 41f, NPN transistor Q1, comparator CP1, resistor R1, and capacitor C1. In this positional deviation detection circuit 41, its comparator CP
The potential of the connection point P1 between the resistor R1 connected to the collector of the transistor Q1 and the capacitor C1 and the output voltage Va of the potentiometer 47 are set to the non-inverting input terminal and the inverting input terminal of the transistor Q1. There is. In addition, the motor drive time calculation circuit 42
are an OR gate 42a whose inputs are the outputs of the negative logic input AND gates 41e and 41f of the positional deviation detection circuit 41, an NPN transistor Q2 whose base input is the output of the OR gate 42a, a comparator CP2, resistors R2 to R5, and a capacitor C2. , C3. In this motor drive time calculation circuit 42, the comparator
The non-inverting input terminal and the inverting input terminal of CP2 are set so that the potential at the connection point between the resistor R2 connected to the collector of the transistor Q2 and the capacitor C2 and the divided voltage Vb between the resistor R4 and the resistor R5 are set. It's summery. Further, the rotational direction determination circuit 43 includes a negative logic input AND gate 41 of the positional deviation detection circuit 41.
The outputs of e and 41f are input to one end side.
The output of the NOR gates 43a and 43b is input to one end of the negative logic input AND gates 44a and 44b of the AND gate circuit 44. The output of the comparator CP2 in the motor drive time calculation circuit 42 is input to the other end of the negative logic input AND gates 44a and 44b.

Next, the operation of the cornering lamp system configured as described above will be explained. That is, the steering wheel is now in the straight steering position, and the sub-reflector 5 is
b is located at the center of rotation, and the irradiation direction of the headlamp 5 is directed to the front. At this time, from the output terminal 3c of the control signal generation circuit 3, the
Since the count value in the UP/DOWN counter 32 is zero, the control signal to the motor control circuit 4 is sent periodically (20 msec period) with a duty ratio of 50%.
A pulse signal is being sent. i.e. this 50
% duty ratio periodic pulse signal (control signal) is sent to the fail-safe circuit 4 via the terminal 4a.
Since the signal input to A and then input to the retriggerable one shot RT via the inverter INV is inverted within 40 msec, its Q output is at the "H" level, and its Q bar output is at the "H" level. The "L" level is maintained, so the control signal passes through AND1 and is input to the positional deviation detection circuit 41 of the servo motor control circuit 4B via the OR gate OR1.

In this situation, if you turn the steering wheel and start steering to the right, for example, the steering wheel will change depending on the amount of right steering.
The count value in the UP/DOWN counter 32 goes up, and according to the up count value,
Comparator 34 via D/A converter 33
The voltage value set at the inverting input terminal of the voltage decreases. Therefore, the duty ratio of the pulse signal sent out from the output terminal of the comparator 34, that is, the control signal input to the motor control circuit 4 via the output terminal 3c of the control signal generation circuit 3 increases, and the pulse signal of the control signal increases. The width will increase according to the amount of right steering.

Now, by steering the steering wheel to the right from the straight-ahead steering position, the duty ratio of the control signal input to the motor control circuit 4 increases, and the pulse width of the control signal widens, as shown in FIG. 5a. Assume that the pulse width becomes W1 compared to the pulse width W during straight-ahead steering. This control signal passes through AND1 in fail-safe circuit 4A, and OR gate OR1
is input to the positional deviation detection circuit 41 of the servo motor control circuit 4B via the control signal, and at the rising edge of this control signal (point a shown in FIG.
At point a shown in FIG. b), the transistor Q1 becomes non-conductive. Due to this non-conduction of the transistor Q1, the capacitor C1 starts to be charged via the resistor R1, and the potential at the connection point P1 between the capacitor C1 and the resistor R1, that is, the running potential to the non-inverting input terminal of the comparator CP1 increases. It begins to rise (point a shown in Figure 5c). On the other hand, at this time, comparator CP1
The voltage set via the potentiometer 47 at the inverting input terminal of the electric motor 46 (Va shown in FIG. The value corresponds to the center position (2.5V in this embodiment). Therefore,
When the potential of the connection point P1 input to the non-inverting input terminal exceeds the voltage Va set to the inverting input terminal (point b in Figure 5 c), the output of the comparator CP1 goes to the "H" level. (Fig. 5 d)
point shown). When the base voltage of transistor Q1 returns to the "H" level at the falling edge of the control signal shown in FIG. 5a (FIG. 5b),
point), the potential set to the non-inverting input terminal immediately becomes approximately equal to the ground potential (point c in Figure 5c),
The output of the comparator CP1 becomes "L" level (point c shown in FIG. 5d). That is, in the pulse width W1 of the control signal, the path width (ΔW=W1-W) is determined by the difference from the pulse width W during straight steering.
Then, the output level of the comparator CP1 becomes "H". And the output of this comparator CP1 is
Output of negative logic input AND gate 41e (Fig. 5h)
This “H” level signal with a pulse width of ΔW is used to calculate the motor drive time as the amount of positional deviation between the target illumination direction of the headlight and the actual illumination direction, which is determined in association with the steering wheel steering angle. It comes to be input to the circuit 42 and the rotation direction determination circuit 43.
In addition, Fig. 5 e, f, g and i are respectively
The outputs of the NOR gate 41b, inverter 41c, inverter 41d, and negative logic input AND gate 41f are shown.

The output of the negative logic input AND gate 41e input to the motor drive time calculation circuit 42 is the output of the OR gate 4.
2a and becomes the base input of transistor Q2 (FIG. 5j). This results in transistor Q
2 is turned on for its pulse width ΔW, and the set voltage to the non-inverting input terminal of the comparator CP2 begins to drop due to the discharge of the charge of the capacitor C2 through the resistor R2 (point b in FIG. 5k). and,
When the set voltage to this non-inverting input terminal falls below the divided voltage (Vb shown in Figure 5k) of resistor R4 and resistor R5 set to the inverting input terminal, the output of comparator CP2 becomes It becomes "L" level (point d in Figure 5 l). Then, at point c in FIG. 5j, when transistor Q2 is turned off,
Capacitor C2 comes to be charged via resistor R3, and the set voltage to the non-inverting input terminal of comparator CP2 gradually increases. When the set voltage to the non-inverting input terminal rises and exceeds the divided voltage Vb set to the inverting input terminal (point e in Figure 5), the output of the comparator CP2 goes to the "H" level. (point e in Figure 5 l). That is, the output of the comparator CP2 becomes "L" level for a time period τ corresponding to the pulse width ΔW detected as the amount of positional deviation between the target irradiation direction determined in association with the steering wheel steering angle and the actual irradiation direction,
The output of this comparator CP2 (positional deviation calculation signal) is input to the negative logic input AND gates 44a and 44b of the AND gate circuit 44.
In this embodiment, capacitor C2 and resistor R
3, the charging time constant determined by the capacitor C
2 and the resistor R2, and the design values of the charging time constant and the discharging time constant determine the value of time τ (positional deviation calculation time) according to the above ΔW. Needless to say, it is possible to adjust the

On the other hand, the outputs of the NOR gates 43a and 43b in the rotational direction discrimination circuit 43 (Fig. 5 m and n) are the negative logic input MND of the positional deviation detection circuit 41.
At the rising edge of the positional deviation detection signal with a pulse width of ΔW sent by the gate 41e, it is inverted to the "L" and "H" levels, so the positional deviation calculation signal of the comparator CP2, which is generated τ ₁ hour later than this, is It passes through the negative logic input AND gate 44a side and is output (FIG. 5o), and this negative logic input AND
Based on the "H" level positional deviation calculation signal sent from the gate 44a, the levels of the output terminals 45a and 45b of the motor driver 45 become "H" and "L" from the intermediate level position (Fig. 5q and r). ,
During the positional deviation calculation time τ, a drive current in the A direction is supplied to the electric motor 46. That is, by supplying the drive current in the A direction, the drive shaft 46a of the electric motor 46 rotates clockwise, and the rotation of the sub-reflector 5b accompanying the rotation of the output shaft 46a in the clock direction causes rotation of the sub-reflector 5b. As a result, the direction of illumination of the headlight 5 becomes variable to the right (handle steering direction) as viewed from the driver's seat (see FIG. 6). When the irradiation direction of the headlight 5 changes to the right, a voltage is set to the non-inverting input terminal of the comparator CP1 via the potentiometer 47 according to the rotation angle position of the output shaft 46a of the electric motor 46.
As Va increases, the pulse width ΔW of the positional deviation detection signal determined based on the next control signal sent via the control signal generation circuit 3 becomes narrower, and the positional deviation calculation time τ corresponding to this ΔW is shortened. The operation is repeated, and the pulse width ΔW of the position deviation detection signal
At the point when becomes zero, the target irradiation direction and the actual irradiation direction of the headlamp 5 will accurately match.
The positional deviation calculation time τ becomes shorter as the irradiation direction of the headlight 5 approaches the target irradiation direction, and accordingly, the drive current supplied to the electric motor 46 is cut off during one cycle of the control signal. but,
That is, the drive current is intermittently supplied only during the position deviation calculation time τ for each cycle of the control signal, but after the drive current is cut off, the inertia force causes the electric motor 46 to rotation continues,
Partly because the period of the control signal is short, the sub-reflector 5b rotates as if linearly, and the irradiation direction of the headlamp 5 matches the target irradiation direction. Moreover, as the irradiation direction of the headlight 5 approaches the target irradiation direction, the supply time of the drive current becomes shorter, so the inertial force is gradually weakened and the point where the actual irradiation direction and the target irradiation direction match This makes it possible to prevent the electric motor 46 from overrunning.

The above has described the operation in the case of right steering starting from the straight steering position, but in the case of left steering starting from the straight steering position, the count value in the UP/DOWN counter 32 decreases and this Since the voltage value set at the inverting input terminal of the comparator 34 increases in accordance with the down count value,
Positional deviation detection circuit 4 of servo motor control circuit 4B
1, the duty ratio of the control signal input to the output terminal 1 is reduced. Now, by steering the steering wheel to the left from the straight-ahead steering position, the duty ratio of the control signal decreases, and the pulse width of this control signal becomes narrower, as shown in FIG. Assume that the pulse width becomes W2. That is, at the rising edge of this control signal, transistor Q1 becomes non-conductive, and comparator CP
The potential set to the non-inverting input terminal of No. 1 begins to rise (point a1 in FIG. 7c). And this comparator
At the point when the potential set to the non-inverting input terminal of CP1 exceeds the voltage Va set to the inverting input terminal (point c1 in Fig. 7c), the output of comparator CP1 becomes "H" level and at the same time (c1 in Fig. 7d)
point), the base potential of the transistor Q1 becomes "H" level (point c1 in FIG. 7b). Therefore,
At this point, transistor Q1 becomes conductive,
Since the set potential of the non-inverting input terminal of comparator CP1 is approximately equal to the ground voltage, the comparator
The output of CP1 instantly becomes inverted to the "L" level. On the other hand, negative logic input AND gate 41f
The output becomes "H" level at the falling edge of the control signal shown in Figure 7a (b1 in Figure 7i).
point), becomes the "L" level due to the instantaneous output of the "H" level from the comparator CP1. That is,
In the pulse width W of the control signal during straight steering, the output of the negative logic input AND gate 41f becomes "H" level at a pulse width (ΔW'=W-W2) determined by the difference from the pulse width W2 during left steering. , this "H" level signal with a pulse width of ΔW' is used as the amount of positional deviation between the target irradiation direction determined in association with the steering wheel steering angle and the actual irradiation direction of the headlight, and is calculated by the motor drive time calculation circuit. 42 and a rotation direction determination circuit 43. Upon receiving this positional deviation detection signal with a pulse width of ΔW′,
The motor drive time calculation circuit 42 generates a misalignment calculation signal of time τ' corresponding to this pulse width ΔW' (FIG. 7l). On the other hand, the outputs of the NOR gates 43a and 43b in the rotational direction discrimination circuit 43 (Fig. 7 m and n) are inverted to "H" and "L" levels at the rising edge of the positional deviation detection signal with a pulse width of ΔW'. Therefore, the position deviation calculation signal that occurs with a delay of τ′ time is the negative logic input.
Passes through the AND gate 44b side and is output (7th
Figure p), based on the "H" level positional deviation calculation signal sent from this negative logic input AND gate 44b,
Output terminals 45a and 45b of motor driver 45
The level becomes "L" and "H" from the intermediate level position (Fig. 7 q and r), and a drive current in the B direction is supplied to the electric motor 46 during the position deviation calculation time τ'. . That is, by supplying the drive current in the B direction, the drive shaft 46a of the electric motor 46 rotates counterclockwise, and the rotation of the sub-reflector 5b due to the counterclockwise rotation of the drive shaft 46a causes the drive shaft 46a to rotate counterclockwise. Therefore, the irradiation direction of the headlight 5 can be varied to the left (handle steering direction) when viewed from the driver's seat side. When the irradiation direction of the headlight 5 changes to the left, the voltage Va set to the non-inverting input terminal of the comparator CP1 via the potentiometer 47 changes depending on the rotation angle position of the drive shaft 46a of the electric motor 46. The pulse width ΔW' of the positional deviation detection signal determined based on the next control signal sent out via the control signal generation circuit 3 is narrowed, and the positional deviation calculation time τ' corresponding to this ΔW' is shortened. This operation is repeated, and when the pulse width ΔW' of the positional deviation detection signal becomes zero, the target irradiation direction and the actual irradiation direction of the headlamp 5 come to match. In addition, in this embodiment, the operation when steering to the right and steering to the left from the straight-ahead steering position was explained, but the operation when steering to the left after steering to the right,
Even in the case of right steering after left steering, the irradiation direction of the headlight 5 follows the steering angle and changes linearly in the same way.

Next, the operation of the failsafe circuit 4A in the cornering lamp system that performs such basic operations will be explained. That is, for example, suppose that the input line for the control signal to the motor control circuit 4 is shorted to the GND potential at point a shown in FIG. That is, the figure a shows the voltage waveform of the control signal generated at the connection point between the resistor R0 and the input terminal 4a, the figure b shows the output waveform of the inverter INV, the figure c shows the Q output waveform of the retriggerable one-shot RT, and the figure Figure d shows the Q bar output waveform, Figure e shows the feedback signal waveform sent out by the oscillator OS, Figure f shows the output waveform of the OR gate ORI, and the input line of the control signal is at point a shown in the figure. When shorted to the GND potential, the voltage level of the control signal generated at the connection point between the resistor R0 and the input terminal 4a becomes "L", and the output level of the inverter INV becomes "H". If this state continues for 40 msec or more, at point b shown in the figure, the Q output of the retriggerable one-shot RT is inverted to "L" level, its Q bar output is inverted to "H" level, and the gate of AND1 is inverted. is closed, and the AND2 gate is opened in its place. Therefore, from now on, this
The return signal (Fig. 8 e) sent from the oscillator OS now passes through AND2, and this return signal passes through the OR gate OR1 to the servo motor control circuit 4B.
It is now input to the positional deviation detection circuit 41 of. That is, the positional deviation detection circuit 41 includes an oscillator.
A periodic pulse-like electrical signal (return signal) with a duty ratio of 50% sent out by the OS is now input, and based on this return signal, the irradiation direction of the headlight 5 is forcibly directed toward the front. It will be returned to and fixed.

In addition, if the input line of the control signal to the motor control circuit 4 becomes open due to a disconnection or the like, for example at point a in FIG. 9, the resistor R0 and the input terminal 4a
The voltage level of the control signal generated at the connection point becomes "H", and the output level of the inverter INV becomes "L". If this state continues for 40 msec or more, at point b shown in the figure, the Q output of the retriggerable one-shot RT is inverted to "L" level, the Q output is inverted to "H" level, and the gate of AND1 is inverted. At the same time as it is closed, the gate of AND2 is opened, and in the same manner as described above, the return signal (Fig. 9 e) passing through this AND2 is inputted to the position deviation detection circuit 41 of the servo motor control circuit 4B via the OR gate OR1. Based on this return signal, the irradiation direction of the headlight 5 is forcibly returned to the front direction and fixed.

That is, when the control signal sent out by the control signal generation circuit 3 is directly input to the positional deviation detection circuit 41 of the servo motor control circuit 4, the above-mentioned shorting of the control signal line to the GND potential is necessary. In the case where an open state occurs due to wire breakage or the like, the illumination direction of the headlight 5 will reach the maximum deflection angle position in the left or right direction and become fixed. By providing such a fail-safe circuit 4A, in the event that an unexpected situation occurs where the periodic control signal is no longer inputted via the control signal generation circuit 3 due to some factor,
The irradiation direction of the headlight 5 is forcibly returned to the front direction and fixed, thereby ensuring safety during driving in this unexpected situation.

As described above, according to the cornering lamp system according to the present embodiment, the irradiation direction of the headlight 5 can be linearly varied by following the steering angle using the electric motor 46. Compared to a cornering lamp system, the system structure can be simplified, and there is no need for a special design depending on the vehicle type. Furthermore, since it is possible to perform variable operation of the irradiation direction of the headlight 5 only at night, its durability can be greatly improved. In such a case that a periodic control signal is no longer input through the headlamp, a fail-safe operation is provided in which the direction of illumination of the headlight 5 is forcibly returned to the front direction and fixed. Become.

In addition, in this embodiment, a fail-safe operation was used in which the irradiation direction of the headlamp 5 was forcibly returned to the front direction and fixed, but the fixed position of the irradiation direction does not necessarily have to be directly in front of the user. In order to ensure visibility for the person, the swing angle position may be set slightly to the left of the front.

〔Effect of the invention〕

As explained above, according to the vehicle cornering lamp system according to the present invention, a control signal having a pulse width corresponding to a steering angle is periodically generated, and based on the generated control signal, the actual lighting means is controlled. The positional deviation between the irradiation direction of the lamp and the target irradiation direction determined in association with the steering angle is detected, and the irradiation direction of the lighting means is varied by driving an electric motor to make this detected positional deviation zero. In addition, if the control signal is not input even after a predetermined period, a return signal is sent in place of the control signal, and the irradiation direction of the lighting means is forcibly returned to approximately the front direction. Since it is fixed, it is possible to linearly vary the irradiation direction of the lighting means by following the steering angle using an electric motor, which makes the system more efficient than conventional mechanical cornering lamp systems. The structure is simplified, there is no need for a special design depending on the vehicle type, the irradiation direction can be varied only at night, and the durability can be greatly improved. In addition, in the case of an unexpected situation in which the control signal is not input even after a predetermined period, the irradiation direction of the lighting means is forcibly returned to the substantially front direction and fixed. It will be possible to ensure safety while driving.

[Brief explanation of the drawing]

FIG. 1 is a block circuit configuration diagram showing an embodiment of a vehicle cornering lamp system according to the present invention, FIG. 2 is an external perspective view of a headlamp whose irradiation direction is variable using this cornering lamp system, and FIG. Figure 3 is an external perspective view showing the deceleration drive mechanism connected to the electric motor in this cornering lamp system, and Figure 4 specifically shows the internal configuration of the servo motor control circuit in the cornering lamp system shown in Figure 1. 5 is a time chart explaining the operation of this cornering lamp system when steering to the right from a straight steering position, and FIG. 6 is a cross-sectional plan view of the headlight shown in FIG. FIG. 7 is a time chart illustrating the operation of this cornering lamp system when steering to the left from a straight ahead steering position, and FIGS. 8 and 9 are time charts illustrating the operation of the fail-safe circuit in this cornering lamp system. . 3...Control signal generation circuit, 31...Rotation direction determination circuit, 32...UP/DOWN counter, 33...
...D/A converter, 34...Triangular wave generator, 3
4...Comparator, 4...Motor control circuit, 4
A...Fail-safe circuit, INV...Inverter, RT...Retriggerable one shot, OS...
...oscillator, AND1, AND2...and gate,
OR1...OR gate, 4B...Servo motor control circuit, 41...Position shift detection circuit, 42...Motor driving time calculation circuit, 43...Rotation direction discrimination circuit, 44...AND gate circuit, 45...Motor driver , 46... electric motor, 47... potentiometer.

Claims (1)

[Claims] 1. In a vehicle cornering lamp system that changes the irradiation direction of a lighting means in conjunction with steering wheel steering, the control signal generating means periodically generates a control signal with a pulse width corresponding to the steering angle, and the control signal generating means a positional deviation detection means for detecting a positional deviation between an actual irradiation direction of the lighting means and a target irradiation direction determined in association with the steering angle based on a control signal to be generated; and a positional deviation detected by the positional deviation detection means. irradiation direction variable means for driving an electric motor to vary the irradiation direction of the lighting means in order to make the control signal zero; and return signal sending means for forcibly returning and fixing the irradiation direction of the lighting means substantially toward the front.