JP2000071865A - Automatic optical axis adjusting device for head light - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the radiating direction of a head light in the normal condition by measuring a distance between a body over wheels and a lower arm fitted to the wheels with a distance measuring means, and controlling an optical axis adjusting means on the basis of the measured value of the distance measuring means. SOLUTION: A main control circuit 22 computes a distance between a front ultrasonic sensor 11 and a lower arm and a distance between a rear ultrasonic sensor 15 and the lower arm, and thereafter, computes a difference between both the distances so as to detect the inclining condition of a vehicle. In the case where the distance between the front ultrasonic sensor 11 and the lower arm is longer than the distance between the rear ultrasonic sensor 15 and the lower arm, since the rear seat side of the vehicle is sunken and a driver's seat side is floated, the radiating direction of head lights 37, 31 is directed upward. The main control circuit 22 corrects the radiating direction of the head lights 37, 31 to the downward direction through a head light optical axis driving device 23, and maintains the radiating direction of the head lights 37, 31 in the normal condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic headlight optical axis adjusting device which can maintain the irradiation direction of a headlight in a normal state by detecting an inclination state of a vehicle body.

[0002]

2. Description of the Related Art Conventionally, a so-called halogen lamp in which a halogenated gas is sealed in an incandescent lamp is generally used as a vehicle headlight. This halogen lamp has an advantage that it can emit a large light flux more efficiently than an incandescent lamp or the like.

In recent years, HID (High-voltage sodium lamps, metal halide lamps, etc.) have recently been developed.
Intensity Discharge Lamp)
Attempts have been made to use discharge lamps as headlights for vehicles. This discharge lamp is a lamp that has been widely used as a street lamp so far, and can be driven with low power and has a large amount of light emission, so that it is also suitable as an in-vehicle headlight. This discharge lamp is configured such that a pair of electrodes and an ionizable enclosure are accommodated in an arc tube, and a high voltage is applied between the pair of electrodes to break the insulating state due to the enclosed gas, and the ions between the electrodes are destroyed. The flow is started and an arc discharge is generated, thereby outputting light.

When a large number of people are loaded on the rear seats or a large amount of luggage is loaded on the trunk, the vehicle body tilts downward and the vehicle headlights face upward. In such a state, since the HID discharge lamp emits a large amount of light, the driver of the oncoming vehicle or the preceding vehicle may obstruct the view,
There was a risk of causing a traffic accident. For this reason, an automatic optical axis adjustment device that automatically adjusts the optical axis of a vehicle headlight to an appropriate position has been proposed.

FIG. 5 is a configuration diagram showing a conventional headlight automatic optical axis adjusting device disclosed in Japanese Patent Application Laid-Open No. 9-2148, for example. In the figure, reference numeral 1 denotes an ultrasonic sensor including a pair of transmitting and receiving ultrasonic vibrators and the like, which are provided on the front and rear end sides of the automobile so as to face the road surface G, respectively. Reference numeral 2 denotes an ultrasonic transmission / reception circuit which emits a predetermined pulsed ultrasonic wave from the ultrasonic sensor 1 and detects a reflected wave of each ultrasonic sensor 1 for each ultrasonic emission.

Reference numeral 3 denotes a control circuit for calculating an angle of the vehicle with respect to the road surface G based on each arrival time of each reflected wave to each ultrasonic sensor 1. Reference numeral 4 denotes a driving circuit for driving the headlight optical axis driving device 6 in response to a signal g from the control circuit 3, and reference numeral 5 denotes a position of the output shaft of the headlight optical axis driving device 6, and the detection signal V is used as a control circuit. Reference numeral 6 denotes a position sensor for outputting to the headlight 3, and a headlight optical axis driving device 6 for automatically adjusting the irradiation angle of the headlight 7 based on a signal g from the control circuit 3.

Next, the operation will be described. The ultrasonic transmission / reception circuit 2 emits a predetermined pulsed ultrasonic wave to the road surface G from the ultrasonic sensors 1 provided on the front and rear end sides of the vehicle, and emits the reflected waves by each ultrasonic sensor 1. Detect each time. Then, the control circuit 3 determines the road surface G of the vehicle based on the respective arrival times of the respective reflected waves to the respective ultrasonic sensors 1.
Is calculated, and the calculation result and the position sensor 5 are calculated.
And outputs a signal g to the drive circuit 4 in accordance with the detection signal V from The drive circuit 4 automatically adjusts the irradiation angle of the headlight 7 based on the signal g.

[0008]

A conventional headlight automatic optical axis adjusting device is constructed as described above.
On uneven roads or snowy roads with irregularities, the distance from the road surface to the vehicle bottom (vehicle ground height) cannot be accurately measured, and, for example, the irradiation direction of the headlights becomes upward, causing dazzling oncoming vehicles. There were issues such as.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and can detect a leaning state of a vehicle body without being affected by a road surface condition, and can maintain a normal irradiation direction of headlights. An object of the present invention is to obtain a headlight automatic optical axis adjusting device.

[0010]

Means for Solving the Problems An automatic optical axis adjusting device for a headlight according to the present invention measures a distance between a body above a wheel and a lower arm attached to the wheel by distance measuring means. The optical axis adjusting unit is controlled based on the measurement value of the distance measuring unit, and the irradiation direction of the headlight is maintained in a normal state by the control unit.

In the headlight automatic optical axis adjusting device according to the present invention, the distance measuring means is an ultrasonic sensor for measuring a distance between a body above the wheel and a lower arm attached to the wheel. It was done.

[0012] In the headlight automatic optical axis adjusting device according to the present invention, the distance measuring means includes a coil constituting an oscillator mounted on the body above the wheel and the body above the wheel, and an oscillation state of the oscillator. By detecting the change, the distance between the coil and the lower arm is measured by a magnetic field distance measuring device.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a configuration diagram showing a headlight automatic optical axis adjustment device according to Embodiment 1 of the present invention, and FIG. 2 is a mounting position of an ultrasonic sensor of the headlight automatic optical axis adjustment device according to Embodiment 1 of the present invention. FIG.
In the figure, reference numeral 11 denotes a front ultrasonic sensor (distance measuring means) for measuring a distance between a body 13 above a front wheel 12 and a lower arm 14 attached to the front wheel 12;
Reference numeral 5 denotes a rear ultrasonic sensor (distance measuring means) for measuring a distance between a body 17 above the rear wheel 16 and a lower arm 18 attached to the rear wheel 16.

Reference numeral 19 denotes a sensor switching circuit for connecting one of the front ultrasonic sensor 11 and the rear ultrasonic sensor 15 to the main control circuit 22, and reference numeral 20 denotes a front ultrasonic sensor 11 or a rear ultrasonic sensor inputted via the sensor switching circuit 19. A receiving circuit that outputs measurement data from the ultrasonic sensor 15 to the main control circuit 22, outputs an instruction command from the main control circuit 22 to the front ultrasonic sensor 11 or the rear ultrasonic sensor 15 via the sensor switching circuit 19. This is a transmission circuit.

Numeral 22 inputs the measurement data from the front ultrasonic sensor 11 and the rear ultrasonic sensor 15 while switching the sensor switching circuit 19, the distance between the front ultrasonic sensor 11 and the lower arm 14, and the rear ultrasonic sensor. Fifteen
A main control circuit (control means) for calculating a distance between the lower arm 18 and the lower arm 18. The main body circuit posture is detected from the calculated result, and the irradiation direction of the headlight is set to a normal state via the headlight optical axis driving device 23. To hold.

Reference numeral 23 denotes a headlight optical axis driving device (optical axis adjusting means) for driving the stepper motors 25 and 29 via motor drivers 24 and 28 to operate the headlight inclination changing devices 26 and 30, respectively. Headlight 2
It is a headlight inclination changing device (optical axis adjusting means) for changing the irradiation direction of 7, 31. 32 applies a voltage to the main control circuit 22 and, when the ignition switch 33 is turned off, a distance between the front ultrasonic sensor 11 and the lower arm 14, and a distance between the rear ultrasonic sensor 15 and the lower arm 18. It is a power supply circuit reset circuit for resetting the calculation result of the distance.

Next, the operation will be described. FIG. 3 is a waveform diagram showing a state of distance measurement in the headlight automatic optical axis adjusting device according to Embodiment 1 of the present invention. First,
When the ignition switch 33 is turned on and a voltage is applied to the main control circuit 22, the main control circuit 22 instructs the sensor switching circuit 19 to connect to the front ultrasonic sensor 11. Then, the main control circuit 22 outputs an ultrasonic signal from the transmission circuit 21 after the connection between the sensor switching circuit 19 and the front ultrasonic sensor 11 is performed. This ultrasonic signal
As shown in FIG. 3A, nine 40-kHz rectangular waves are output.

The receiving circuit 20 outputs the ultrasonic signal from the transmitting circuit 21 at the same time as receiving the ultrasonic signal reflected through the lower arm 14, and as shown in FIG. To the main control circuit 22. Here, the receiving circuit 20 requires twice as long as the transmission signal output from the transmission circuit 21. And the main control circuit 2
In step 2, the distance between the front ultrasonic sensor 11 and the lower arm 14 is calculated based on the following equation.

L (m) = 1/2 × C × TT T: Time from when the ultrasonic signal is output from the transmitting circuit 21 to when the receiving circuit 20 receives the ultrasonic signal C: Airborne propagation of the ultrasonic wave Speed (331.45 + 0.607)
t (m / s)) t: temperature

Next, the main control circuit 22 includes the sensor switching circuit 1
After instructing the rear ultrasonic sensor 9 to connect to the rear ultrasonic sensor 15, the distance between the rear ultrasonic sensor 15 and the lower arm 18 is calculated as in the case of the front ultrasonic sensor 11. Then, after calculating the distance between the front ultrasonic sensor 11 and the lower arm 14 and the distance between the rear ultrasonic sensor 15 and the lower arm 18, the main control circuit 22 calculates the difference between the distances, and calculates the inclination of the vehicle. Detect state.

Here, when the distance between the front ultrasonic sensor 11 and the lower arm 14 is longer than the distance between the rear ultrasonic sensor 15 and the lower arm 18, the rear seat of the vehicle sinks and the driver's seat sinks. Since it is floating, the irradiation direction of the headlights 27 and 31 is upward. Therefore,
The main control circuit 22 corrects the irradiation direction of the headlights 27 and 31 downward through the headlight optical axis driving device 23, and holds the irradiation directions of the headlights 27 and 31 in a normal state.

When the distance between the front ultrasonic sensor 11 and the lower arm 14 is shorter than the distance between the rear ultrasonic sensor 15 and the lower arm 18, the rear seat of the vehicle floats and the driver's seat sinks. Headlights 2
The irradiation direction of 7, 31 is downward. Therefore, the main control circuit 22 corrects the irradiation direction of the headlights 27 and 31 upward through the headlight optical axis driving device 23,
The irradiation direction of the headlights 27 and 31 is maintained in a normal state.

In the above embodiment, the front ultrasonic sensor 11 and the rear ultrasonic sensor 15 are mounted on the body 13 above the front wheel 12 or the body 17 above the rear wheel 16, respectively. The ultrasonic wave may be reflected on the bodies 13 and 17 by attaching the ultrasonic wave to the body 18.

As described above, according to the first embodiment, the posture of the vehicle body is determined by the front ultrasonic sensor 11 and the lower arm 14.
And the distance between the rear ultrasonic sensor 15 and the lower arm 18, the inclination state of the vehicle body is detected without being affected by the road surface condition, and the irradiation direction of the headlights 27 and 31 is detected. Can be maintained in a normal state.

Embodiment 2 FIG. 4 is a block diagram showing a headlight automatic optical axis adjusting device according to a second embodiment of the present invention. In the figure, the same reference numerals as those in the first embodiment denote the same or corresponding parts, and a description thereof will be omitted. .
Reference numerals 35 and 36 denote coils (distance measuring means) constituting oscillators attached to the body 13 above the front wheel 12 and the body 17 above the rear wheel 16, and 41 and 42 denote coils 3
The coils 35, 36 and the lower arms 14, 18 are resonated by detecting the change in the oscillation frequency.
Is a magnetic field distance measuring device that measures the distance between the two. Note that a change in the oscillation amplitude may be detected instead of the oscillation frequency.

Next, the operation will be described. The magnetic field distance measuring devices 41 and 42 cause the coils 35 and 36 to resonate by passing a current through the coils 35 and 36, respectively. And
When the distance between the coils 35 and 36 and the lower arms 14 and 18 changes, the oscillation frequency of the oscillator changes due to the influence of the eddy current loss. The magnetic field distance measuring devices 41 and 42 detect the change state of the oscillation frequency of the oscillator and output it to the main control circuit 22. Then, the main control circuit 22 measures the distance between the coils 35 and 36 and the lower arms 14 and 18 based on the input change state of the oscillation frequency. And
After calculating the distance between the coil 35 and the lower arm 14 and the distance between the coil 36 and the lower arm 18, the main control circuit 22 calculates the difference between the distances and detects the lean state of the vehicle.

Here, when the distance between the coil 35 and the lower arm 14 is longer than the distance between the coil 36 and the lower arm 18, the rear seat of the vehicle sinks and the driver's seat floats. The irradiation direction of the lights 27 and 31 is upward. Therefore, the main control circuit 22 controls the headlights 27 and 27 via the headlight optical axis driving device 23.
The irradiation direction of 31 is corrected downward, and the headlights 27,
The irradiation direction of 31 is maintained in a normal state.

When the distance between the coil 35 and the lower arm 14 is shorter than the distance between the coil 36 and the lower arm 18, the rear seat of the vehicle floats and the driver's seat sinks. The irradiation directions of 27 and 31 are downward. Therefore, the main control circuit 22 controls the headlights 27 and 3 via the headlight optical axis driving device 23.
Correct the irradiation direction of 1 upward, and adjust the headlights 27 and 3
The irradiation direction of No. 1 is maintained in a normal state.

As described above, according to the second embodiment, the posture of the vehicle body is detected from the distance between the coil 35 and the lower arm 14 and from the distance between the coil 36 and the lower arm 18. Thus, the tilting state of the vehicle body can be detected without being affected by the influence of the headlights 27 and 31, and the irradiation direction of the headlights 27 and 31 can be maintained in the normal state.

[0030]

As described above, according to the present invention, the distance between the body above the wheel and the lower arm attached to the wheel is measured by the distance measuring means. Since the control unit controls the optical axis adjusting unit based on the above, and maintains the irradiation direction of the headlight light in the normal state by the control unit, the tilting state of the vehicle body is detected without being affected by the road surface condition, and the headlight is detected. There is an effect that the irradiation direction can be maintained in a normal state.

According to the present invention, since the distance measuring means is constituted by the ultrasonic sensor for measuring the distance between the body above the wheel and the lower arm attached to the wheel, the distance measuring means is not affected by the road surface condition. This has the effect of detecting the leaning state of the vehicle body and keeping the irradiation direction of the headlights in the normal state.

According to the present invention, the distance measuring means is provided by detecting a change in the oscillation state of the oscillator and the coil constituting the oscillator attached to the body above the wheel and the body above the wheel. Because it is composed of a magnetic field distance measuring device that measures the distance between the coil and the lower arm, it is possible to detect the leaning state of the vehicle body without being affected by the road surface condition and maintain the headlight irradiation direction in the normal state. There is.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a headlight automatic optical axis adjusting device according to a first embodiment of the present invention;

FIG. 2 is a configuration diagram showing a mounting position of an ultrasonic sensor of the headlight automatic optical axis adjusting device according to the first embodiment of the present invention;

FIG. 3 is a waveform diagram showing a state of distance measurement in the headlight automatic optical axis adjusting device according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram showing a headlight automatic optical axis adjusting device according to a second embodiment of the present invention;

FIG. 5 is a configuration diagram showing a conventional headlight automatic optical axis adjusting device disclosed in, for example, Japanese Patent Application Laid-Open No. 9-2148.

[Explanation of symbols]

11 front ultrasonic sensor (distance measuring means), 12 front wheel, 13, 17 body, 14, 18 lower arm, 1
5 rear ultrasonic sensor (distance measuring means), 16 rear wheels,
22 main control circuit (control means), 23 headlight optical axis driving device (optical axis adjusting means), 26, 30 headlight inclination changing device (optical axis adjusting means), 27, 31 headlight, 35, 36 coil (distance Measuring means), 41,
42 Magnetic field distance measuring device (distance measuring means).

Claims (3)

[Claims] 1. An automatic optical axis adjusting device for a headlight having an optical axis adjusting means for tilting and adjusting an optical axis of headlight light in a vertical direction of a vehicle body, comprising: a body above a wheel; and a lower arm attached to the wheel. Distance measuring means for measuring the distance between the two, and control means for controlling the optical axis adjusting means based on the measurement value of the distance measuring means, and for maintaining the irradiation direction of the headlight light in a normal state. An automatic optical axis adjustment device for headlights. 2. The light of a headlight according to claim 1, wherein the distance measuring means is an ultrasonic sensor for measuring a distance between a body above the wheel and a lower arm attached to the wheel. Automatic axis adjustment device. 3. A distance measuring means comprising: a coil constituting an oscillator attached to a body above the wheel and a body above the wheel; and detecting a change in the oscillation state of the oscillator, thereby forming the coil and the lower arm. 2. The automatic optical axis adjusting device for a headlight according to claim 1, further comprising a magnetic field distance measuring device for measuring a distance between the headlights.