JPH10326506A - Apparatus for controlling irradiation direction of lighting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent any large influence on control of a lighting tool in an irradiation direction due to fluctuation of power supply to a stepping motor. SOLUTION: In an irradiation direction control device 1, a driver 4 for directing the irradiation of a lighting tool 5 to a desired direction comprises a stepping motor 6. When a detector 9 detects a power source voltage or current to be supplied to the stepping motor 6, the voltage or current is sent to a controller 3, thus limiting an allowable range of a rotating speed of the stepping motor 6. For example, the controller 3 stepwise or continuously defines the allowable range of the rotating speed of the stepping motor 6 according to a decrease in power source voltage or current. Otherwise, in the case where it is detected that the power source voltage of current is deviated from the predetermined range, the controller 3 stops the control of the stepping motor 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination direction control device for a lamp using a stepping motor as a drive source for directing the illumination direction of the lamp to a desired direction.

[0002]

2. Description of the Related Art There is known a device capable of changing the irradiation direction of a lamp attached to a vehicle by manual operation or automatically, and as the former example, it responds to changes in loading conditions and riding conditions. A so-called leveling device, which adjusts the direction of illumination of a lamp using an operation switch in the vehicle, is known.As an example of the latter, the direction of illumination of a lamp attached to the vehicle due to a change in the attitude of the vehicle is known. There is known a device (so-called auto-leveling device) that constantly corrects the irradiation direction of a lamp so as to cancel the change in the running posture of a vehicle in order to prevent the vehicle from becoming unstable.

This type of apparatus has some driving means for changing the irradiation direction of the lamp within a certain angle range. For example, the tilt angle of the reflecting mirror is controlled by an actuator using a stepping motor. There are devices designed to do this.

[0004]

When the supply voltage to the stepping motor fluctuates in the above-described apparatus, if the driving frequency of the stepping motor exceeds a certain allowable range, the operation of the stepping motor may not be guaranteed. Therefore, for example, in the case where the irradiation direction of a vehicle lamp has turned to an unexpected direction,
There is a problem that an inconvenience such as dazzling a driver or a pedestrian of an oncoming vehicle may occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lighting control apparatus for a lamp using a stepping motor, in which the control of the lighting direction of the lamp is not significantly affected by fluctuations in the power supply to the stepping motor. .

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a detecting means for detecting a power supply voltage or a current supplied to a stepping motor or a change thereof, and a detecting signal from the detecting means. Control means for limiting the permissible range of the rotation speed of the stepping motor in accordance therewith.

Therefore, according to the present invention, the allowable range of the rotation speed of the stepping motor is limited according to the fluctuation of the power supply, so that the stepping motor is not rotated in a state outside its operation guarantee.

[0008]

FIG. 1 shows a basic configuration of an apparatus according to the present invention.

The irradiation direction control device 1 includes a commanding means 2, a control means 3, and a driving means 4. A lamp 5 whose irradiation direction is controlled by the control means 3 via the driving means 4 includes, for example, a vehicle. In the case of a lamp, a headlamp (a fog lamp, a cornering lamp, and the like are included in addition to a headlamp in a narrow sense).

The driving means 4 is provided to direct the irradiation direction of the lamp 5 in a desired direction, and includes a stepping motor 6 and a driving mechanism 7 driven by the stepping motor 6.

The command means 2 is provided with a lamp 5
(For example, when the irradiation direction of the lamp 5 is controlled by a manual operation, the signal is an operation signal thereof. When the irradiation direction of the lamp 5 is automatically controlled, , Which is the detection signal (the detection signal of the vehicle attitude in the case of the auto-leveling device) serving as the basis.

The apparatus 1 is provided with a detecting means 9 for detecting a power supply voltage or current supplied from the power supply 8 to the stepping motor 6 or a change thereof, and the detection result by the detecting means 9 is controlled by the control means. 3 is sent.

The control means 3 limits the allowable range of the rotation speed of the stepping motor 6 according to the power supply voltage or current obtained by the detection means 9 or a change thereof.

FIG. 2 is a conceptual explanatory view of the processing by the control means 3. The supply voltage to the stepping motor 6 (this is referred to as "Vs") is plotted on the horizontal axis, and the stepping motor 6 is plotted on the vertical axis. Rotation speed (ie, drive frequency or pulse rate) (the upper limit is "N
U "and the lower limit is" NL ". ) Conceptually shows an example of the relationship between the two.

For example, as shown by a solid graph line g1 in FIG. 2, the upper limit NU is lowered stepwise as the supply voltage Vs decreases, or as shown by a broken line g2,
If L is reduced stepwise as the supply voltage Vs decreases, the allowable range of the rotational speed (when this is “ΔN”, ΔN = NU−NL) changes the stepwise change of the supply voltage Vs. Can be defined differently according to

It is to be noted that the supply voltage Vs is not limited to this, as shown by the graph lines g1 'and g2' indicated by the dashed line curve in FIG.
May be defined so that NU and NL are continuously reduced with a decrease in. Also, the supply voltage Vs may be replaced with the supply current.

If the power supply voltage or current obtained by the detecting means 9 deviates from the allowable range, the control means 3
Stops the control of the stepping motor 6. this is,
Rather than rotating the stepping motor 6 in a state where operation is not guaranteed, stopping the control of the motor does not change the irradiation direction of the lamp 5 unnecessarily and the irradiation direction does not face an unexpected direction. (That is, the control unit 3 can always grasp the stop position.) This is preferable.

Although FIG. 1 shows a configuration in which the power supply 8 is provided with the detecting means 9 to directly detect the voltage or current supplied to the stepping motor 6, the present invention is not limited to this. A state detecting means for monitoring the rotation state of the stepping motor based on the coil current, position, speed, etc. of the stepping motor may be provided, whereby the influence of the power supply fluctuation may be indirectly detected from the behavior of the stepping motor.

The method of changing the irradiation direction of the lamp 5 by the driving means 4 includes a method of changing the irradiation direction by tilting the entire lamp by the driving means 4 and a method of driving a part of the components of the lamp. There is a way to control. For example, a method of changing the direction of reflected light by tilting the reflecting mirror in the lamp 5 in the vertical plane by the driving means 4 or changing the direction of irradiation light passing through the lens by tilting the lens by the driving means 4. Examples of the method include a method of changing. In addition, instead of tilting the entire reflecting mirror or lens, the main part of the irradiation light may be changed in a desired direction by controlling the position of a part of the reflecting mirror or the lens. A method in which the light / dark boundary in the light distribution pattern of the lamp is changed up and down by moving the light in a predetermined direction by the driving means 4,
The reflecting means and the light source, the lens and the reflecting mirror, or the lens and the shade or the like are appropriately combined and the driving means 4 is used.
Various embodiments are possible depending on the combination of the optical components of the lamp, such as a method of changing the direction of the irradiation light vertically by moving them together.

[0020]

3 to 5 show an embodiment in which the present invention is applied to an irradiation direction control device for a vehicular lamp.

The device 10 is an auto-leveling device for automatically following the change in the attitude of the vehicle to correct the irradiation direction of the lamp. As shown in FIG. It has a built-in ECU (Electronic Control Unit) 11, and input signals to the ECU 11 are detection signals from vehicle height sensors 12, 13 provided on axles before and after the vehicle, and a headlamp switch 1.
4, an ignition signal (hereinafter, referred to as "SW"), which is an engine start signal.
It is described as “Ig”. ), Detection signals from the vehicle speed sensor 15.

The vehicle height sensors 12 and 13 are means for detecting the vehicle posture, and are provided for detecting the vehicle posture (including the vertical inclination in the traveling direction of the vehicle) during stationary and / or motion. , A method to detect the amount of expansion and contraction of the axle suspension, a method to measure the distance between the vehicle height sensor and the ground using detection waves such as ultrasonic waves or laser light, or a method using a gyro sensor (such as a two-wheeled vehicle) Is used.) And the like.

The correction signal output from the ECU 11 is sent to driving units 16 and 16 'for controlling the irradiation directions of the lamps provided on the left and right of the front part of the vehicle. The driving units 16 and 16 'have a stepping motor 1 as a driving source.
6a, 16'a and their motor drive circuits 16b, 1
6'b are provided. In addition, the rotation of the stepping motors 16a and 16'a, for example,
Actuators 16c, 1 provided in 7, 17 '
The sliding axis 6'c is moved in the front-rear direction of the vehicle, whereby the reflecting mirror is tilted in a vertical plane, whereby the direction of the optical axis of the reflecting mirror in the lamp is changed and the lamps 17 and 17 ' The irradiation directions are respectively controlled.

FIG. 4 shows an example of the structure of a main part (however, only one drive unit 16 is shown), and power is supplied to a computer 18, a stepping motor 16a, and a motor drive circuit 16b, which are control centers. The power supply circuit 19 has the function of the detection means 9 described above.

That is, the SW signal and the I signal
The g signal is input via an OR (sum) circuit 21 formed by the diodes 20, 20 '. In other words, the SW signal in this case is an H (high) signal when instructing lighting, an L (low) signal when instructing extinguishing, and the Ig signal is an H signal when the engine is started, and an L signal otherwise. .

The power supply circuit 19 outputs the SW signal or I signal
When the g signal is an H signal, various voltages generated from these signal voltages are supplied to each part of the circuit as a power supply voltage, and a power supply voltage obtained as a signal voltage of the SW signal or the Ig signal (that is, The signal supplies a predetermined power supply voltage to the power supply circuit 19.
v ". ) To the computer 18.

FIG. 5 is a flowchart showing an example of processing in the computer 18. When the operation of the apparatus 10 is instructed by the above-mentioned OR signal (H signal) of the SW signal and the Ig signal, first, in S1, the power supply circuit is started. 19, a supply voltage to the stepping motor 16a (16'a) (this is referred to as "Vm") is detected.

Then, in S2, it is determined whether or not Vm is equal to or more than the upper limit value (hereinafter referred to as "V3").
If m ≧ V3 ”, the process proceeds to S8 and the stepping motor 1
6a (16'a) is stopped, but "Vm <V
If "3", the process proceeds to S3.

In S3, Vm is set to a predetermined value (this is set to "V2").
(Where V2 <V3). ), And if "Vm≥V2", the process proceeds to S7, in which the drive frequency of the stepping motor 16a (16'a) is limited to a predetermined value (this is described as "Fa") or less. I do. Also, "Vm
If <V2 ”, the process proceeds to S4.

In S4, Vm is set to its lower limit (this is referred to as "V
1 "(however, V1 <V2). ), And if “Vm ≧ V1”, the process proceeds to S6, where the driving frequency of the stepping motor 16a (16′a) is set to a predetermined value (this is set to “Fb” (where Fb <Fa)). It is limited to the following. If “Vm <V1”, the process proceeds to S5, where the control of the stepping motor 16a (16′a) is stopped.

In the apparatus 10, however, the allowable range of the driving frequency of the stepping motor 16a (16'a) is defined in two steps according to the power supply voltage, and therefore, the actuator 16c (16'c) Can be defined in a range corresponding to V1 ≦ Vm ≦ V3. Therefore, as long as the range is wider than the supply voltage range of the computer 18, the actuator 16c (16 ')
c) can be controlled without hindrance, and a decrease in the following speed of the actuator due to the influence of the power supply fluctuation can be prevented. In the case of “Vm ≧ V3 or Vm <V1”, the control of the stepping motor 16a (16′a) is stopped to protect the motor and the lamp 17 (1).
By fixing the irradiation direction 7 '), it is possible to prevent the irradiation direction from inadvertently changing, thereby ensuring the safety of night driving.

Note that S2 and S8 described above indicate the control of Vm at the time of overvoltage, but this control is unnecessary if the adverse effect at the time of overvoltage can be prevented by a constant power supply circuit or the like. .

In the above configuration, the detection signal Sv is sent from the power supply circuit 19 to the computer 18. However, as shown by the two-dot chain line in FIG. 4, the detection signal Sv is transmitted to the motor drive circuit 16b (16 '). b), and the stepping motor 16a (16'a)
A configuration that changes the threshold value of the limiter circuit that defines the upper limit value of the driving frequency may be used.

[0034]

As is apparent from the above description, according to the first aspect of the present invention, the allowable range of the rotational speed of the motor is limited according to the fluctuation of the power supplied to the stepping motor. The stepping motor is prevented from being rotated in a state out of its operation guarantee, so that the irradiation direction of the lamp can be prevented from being directed in an unexpected direction.

According to the second aspect of the present invention, the influence of the power supply fluctuation on the rotation control is determined by defining the allowable range of the rotation speed of the stepping motor stepwise or continuously according to the decrease of the power supply voltage or current. It can be hard to receive.

According to the third aspect of the invention, when it is detected that the power supply voltage or the current deviates from the predetermined range, the control operation of the stepping motor is stopped to ensure the control operation. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of an apparatus according to the present invention.

FIG. 2 is a graph for conceptually explaining processing by a control unit;

3 shows an embodiment of the present invention together with FIGS. 4 and 5, and FIG. 3 is a circuit block diagram showing a configuration of the device.

FIG. 4 is a circuit block diagram showing a configuration of a main part of the device.

FIG. 5 is a flowchart showing the flow of processing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Irradiation direction control device, 3 ... Control means, 4 ... Drive means,
5 lamp, 6 stepper motor, 9 detection means

Claims (3)

[Claims] An illumination direction control device for a lamp having a stepping motor as a driving means for directing the illumination direction of the lamp in a desired direction, comprising: And a control means for limiting an allowable range of the rotation speed of the stepping motor in accordance with a detection signal from the detection means. 2. The illumination direction control device for a lamp according to claim 1, wherein when the detection means detects a decrease in the power supply voltage or the current, the control means adjusts the rotation speed of the stepping motor in accordance with the decrease. An illumination direction control device for a lamp, wherein an allowable range is defined stepwise or continuously. 3. The lighting direction control apparatus for a lamp according to claim 1, wherein the control means detects the power supply voltage or the current deviating from a predetermined range by the control means. An irradiation direction control device for a lamp, wherein the control is stopped.