JPH05305845A - Vehicle headlights - Google Patents

Abstract

PURPOSE:To prevent an optical axis from varying in the same direction in the case where a steering wheel is steered in the reverse direction to the turning direction at the time of drift traveling. CONSTITUTION:A steering angle sensor 4 is installed in a steering wheel 5, while each wheel speed sensor 6 is installed in both front and rear wheels 7 and 8. An actuator 2 is driven by an actuator drive circuit according to a steering direction and a steering angle, and an optical axis of a lamp unit 1 is adjusted in the steering direction. At the time of drift traveling, a racing state of each rear wheel is detected by the wheel speed sensor 6, and the actuator 2 is driven by the actuator drive circuit and the optical axis of the lamp unit 1 is put back to the center of a vehicle irrespective of steerage of the steering wheel 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle headlamp.

[0002]

2. Description of the Related Art Among vehicle headlights, for example, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent Laid-Open No. 2-231845, there is known one in which an optical axis is changed in a steering direction in synchronization with steering of a steering wheel based on a detection action of a steering angle sensor.

[0003]

Since the optical axis of the lamp unit is variably controlled in the steering direction of the steering wheel, when the steering wheel is steered in the opposite direction to the turning direction when the wheels drift during turning of the vehicle. The optical axis changes in the direction opposite to the direction the driver wants to see, and depending on the running condition of the vehicle, the direction the driver wants to see and the irradiation direction of the lamp unit may not necessarily match.

Therefore, according to the present invention, the irradiation direction of the lamp unit can be variably controlled to the turning direction when the vehicle turns, and when the steering wheel is steered in the opposite direction to the turning direction when the wheels drift during the turning, (EN) Provided is a vehicle headlamp which can return the irradiation direction of a unit to the center of a vehicle to eliminate the deviation of the irradiation direction and further improve the visibility.

[0005]

Lamp driving means for rotating a lamp unit to change an optical axis, a steering angle sensor for detecting a steering angle of a steering wheel, and wheels for detecting wheel speeds of front wheels and rear wheels. The lamp drive means is drive-controlled based on the speed sensor and the detection actions of the steering angle sensor and the wheel speed sensor, and when the front wheels and the rear wheels are normally rotating, the optical axis of the lamp unit is changed in the steering direction of the steering wheel. Alternatively, it is provided with an optical axis control means for fixing the optical axis of the lamp unit to the center of the vehicle when the rear wheels idle.

[0006]

When the front wheels and the rear wheels are normally rotating, a drive control signal is output from the optical axis control means to the lamp driving means according to the detection value of the steering angle sensor, and the lamp unit is rotated by the required angle in the steering direction. Then, the optical axis is changed in the steering direction.

When the front wheels or the rear wheels are idling, a drive control signal is output from the optical axis control means to the lamp drive means based on the detection action of the wheel speed sensor, and the lamp unit is turned on regardless of the steering direction of the steering wheel. Rotation is controlled so that the shaft becomes the center of the vehicle.

[0008]

An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, 1 is a lamp unit, 2 is an actuator such as a servo motor as a lamp driving means for rotating the lamp unit 1 itself or a reflector (not shown) in the left-right direction to change the optical axis. 2 is driven and controlled by the optical axis control means 3.

Reference numeral 4 is a steering angle sensor for detecting the steering angle of the steering wheel 5, 6a and 6b are wheel speed sensors for detecting the wheel speeds of the front wheels 7a and 7b, and 6c and 6d are the wheel speeds of the rear wheels 8a and 8b. In the wheel speed sensor, the steering angle sensor 4 and the wheel speed sensors 6a to 6d are all connected to the input side of the optical axis control means 3.

FIG. 2 shows the details of the optical axis control means 3.

9 receives the detection signal of the steering angle sensor 4,
A steering direction detection circuit for detecting the steering direction of the steering wheel 5, 10 is a steering angle amount calculation circuit for inputting the detection signal of the steering angle sensor 4 and converting it to a steering angle amount, and 11 is an output of the steering angle amount calculation circuit 10. The steering direction detection circuit 9 and the optical axis angle calculation circuit 11 are optical axis angle calculation circuits that input a signal and convert them into an optical axis change angle amount. The steering direction detection circuit 9 and the optical axis angle calculation circuit 11 of the actuator drive circuit 12 that outputs a drive control signal to the actuator 2. It is connected to the input side.

Reference numeral 13 denotes wheel speed sensors 6a, 6b and 6
c, enter the detection signal 6d, the front wheels 7a, a wheel speed average value V _WFR of 7b, the rear wheels 8a, the wheel speed calculating circuit for calculating the wheel speed average value V _wrr of 8b, the actuator driving circuit 12 Connected to the input side of.

The actuator drive circuit 12 inputs the output signals of the steering direction detection circuit 9 and the optical axis angle calculation circuit 11 to drive the actuator 2 so as to obtain a predetermined optical axis change angle amount in a predetermined direction. Output a signal.

Further, the actuator drive circuit 12
Inputs the output signal of the wheel speed calculation circuit 13, _{compares the} front wheel speed average value V _WFr and the rear wheel speed average value V _WRr, and when the deviation value is equal to or more than a predetermined amount, the actuator 2 has an optical axis A drive control signal is output so as to return to the center.

Taking an FR vehicle (front engine / front drive type vehicle) as an example, this is the rear wheel 8 when turning.
When the vehicle drifts, the rear wheels 8 idle and the front wheel speed average value V _WRr significantly increases as shown by the line b with respect to the front wheel speed average value V _WFr substantially the same as the vehicle speed shown by the line a in FIG. To do.

[0017] Thus, by to return to the wheel idling region original vehicle around the optical axis of the lamp unit 1 after between the rear-wheel average point of change value V _WRr P _1, P ₂ for the front wheel speed average value V _WFR However, it is necessary to avoid the hunting of the actuator 2 in the case where the errors of the front and rear wheel speed average values V _WFr and V _WRr and the idling due to the drift of the rear wheels 8 end in a very short time. Therefore, when the constant α is set and the rear wheel speed average value V _WRr is larger than the value obtained by adding the front wheel speed average value V _WFr and the constant α, the optical axis adjustment by the steering response is released to set the optical axis to the vehicle. It may be controlled so that it returns to the center.

Next, the operation of the apparatus of the above embodiment will be described with reference to the above-mentioned F.
An example of control in the R vehicle will be described with reference to the flowchart shown in FIG.

When a headlamp switch (not shown) is turned on (step 100), the steering angle θ of the steering wheel 5 is detected by the steering angle sensor 4 in step 101, and steering is performed based on the detection signal of the steering angle sensor 4. The steering direction is detected by the direction detection circuit 9, and the steering angle amount calculation circuit 1 is also provided.
0, the optical axis angle calculation circuit 11 determines the optical axis change angle amount, and the respective output signals are output to the actuator drive circuit 12
Entered in.

In step 102, the wheel speed sensors 6a-6d.
When the wheel speeds of the front wheels 7a and 7b and the rear wheels 8a and 8b are detected by the wheel speed calculation circuit 13, the front wheel speed average value V
_WFr and the rear wheel speed average value V _WRr are calculated, and the output signal thereof is input to the actuator drive circuit 12.

In step 103, the wheel speed calculation circuit 13
On the _basis of the output signal of, _whether the front and rear wheels 7, 8 are rotating normally or whether the rear wheels 8 are drifting and idling, based on the determination of the wheel speed value V _WRr > V _WFr + α. To be judged.

If the result in step 103 is negative, it is determined that the front and rear wheels 7, 8 are rotating normally, and step 104
Then, a drive control signal is output from the actuator drive circuit 12 to the actuator 2, and the actuator 2 is driven to move the optical axis of the lamp unit 1 in the steering direction of the steering wheel 5 at a change amount according to the steering angle θ. Change.

If the result in step 103 is affirmative, it is determined that the rear wheels 8 are idling due to drift, and step 105
Then, the drive control signal is output from the actuator drive circuit 12 to the actuator 2, and the actuator 2 is driven to return the optical axis of the lamp unit 1 to the center of the vehicle and fix it.

In step 106, it is determined whether or not the steering angle of the steering wheel 5 is 0 °. If the determination is negative, the process returns to step 105 and the optical axis of the lamp unit 1 is centered on the vehicle until the steering angle of the steering wheel 5 becomes 0 °. Controlled. Step 1
In the affirmative case of 06, the process returns to step 103 and the same optical axis control as described above is performed.

The above is an example of the optical axis control of the lamp unit 1 in the FR vehicle, but in the case of the optical axis control in the FF vehicle (front engine / front drive type vehicle), the idling of the front wheels 7 is detected. Control similar to that described above is performed.

[0026]

As described above, according to the present invention, when the vehicle is turning, it is possible to improve the visibility by changing the optical axis of the lamp unit in the steering direction of the steering and illuminating the steering direction to improve the visibility. Even if the wheel spins due to drift during traveling and the steering is steered in the opposite direction to the turning direction, it is possible to detect the slip of the wheel and control the optical axis of the lamp unit to be the center of the vehicle. As described above, the illumination direction does not change in the direction opposite to the direction that the driver wants to see, and thus there is an advantage that the visibility can be further improved.

[Brief description of drawings]

FIG. 1 is a schematic system diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram of a control circuit of the embodiment.

FIG. 3 is a graph showing front and rear wheel speeds during drift.

FIG. 4 is a flowchart showing an example of the operation of the embodiment.

[Explanation of symbols]

1 ... Lamp unit, 2 ... Lamp driving means, 3 ... Optical axis control means, 4 ... Steering angle sensor, 5 ... Steering, 6 ... Wheel speed sensor, 7 ... Front wheel, 8 ... Rear wheel.

Claims (1)

[Claims] 1. A lamp driving means for rotating a lamp unit to change an optical axis, a steering angle sensor for detecting a steering angle of a steering wheel, and a wheel speed sensor for detecting each wheel speed of front wheels and rear wheels. The lamp drive means is drive-controlled based on the detection actions of the steering angle sensor and the wheel speed sensor, and when the front wheels and the rear wheels are normally rotating, the optical axis of the lamp unit is changed in the steering direction of the steering wheel so that the front wheels or the rear wheels can be rotated. A vehicle headlamp, comprising: an optical axis control means for fixing the optical axis of the lamp unit to the center of the vehicle when idling.