JPH0572972B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD This invention relates to a device for measuring the optical axis position of a headlamp mounted on an automobile. Conventional technology For example, Japanese Patent Application Laid-Open No. 1983-1980 is used to measure and adjust the optical axis position of a headlamp installed in a car.
Those disclosed in Japanese Patent Application Laid-open No. 179639 and Japanese Patent Application Laid-Open No. 147237/1983 are known. This type of device projects direct irradiation light or reflected light from a headlamp onto a predetermined light-receiving screen, uses a light-receiving element, etc. to detect whether or not the light distribution pattern falls within a specified range. The information is fed back to, for example, an industrial robot for optical axis adjustment to operate an adjuster screw attached to a headlamp. Problems to be Solved by the Invention In the conventional method, the irradiated light itself from the headlamp is used as a medium for adjusting the optical axis. Therefore, in order to reflect the irradiated light on the screen, it is necessary to It is necessary to secure a space, and the device itself becomes large-scale. In addition, as headlamps themselves have diversified in recent years due to the increase in car models and the adoption of halogen lamps, it is necessary to move screens etc. according to the type of headlamps, especially on automated lines. The time and accuracy required for axis adjustment tend to be problems. Means for Solving the Problems The present invention provides an optical axis measuring device that uses small-scale equipment and can provide greater accuracy than conventional devices. That is, the present invention relates to a device for measuring the optical axis position prior to optical axis adjustment. The optical axis position is measured using the vertical and horizontal inclinations as media. More specifically, as shown in the examples, the device measures the optical axis position of a headlamp based on the inclination of the lens surface by pressing a measuring head against the lens surface of the headlamp, and the measuring head presses the measuring head against the lens surface of the headlamp. A contact sensor that detects the inclination of the lens surface by coming into contact with at least three measurement points on the surface, and a sensor that is provided in the center of the area surrounded by the three measurement points and presses the sensor. It includes a center rod that can slide in the direction, and detecting means for confirming and detecting that the contact point of each sensor is pressed against the lens surface based on the sliding displacement when the center rod comes into contact with the lens surface. . As a contact type sensor, for example, three potentiometers are used, and these potentiometers are pressed against the lens surface of the headlamp in a direction substantially perpendicular to the surface. Function As the output processing of the three potentiometers mentioned above, the difference in the output of each potentiometer is calculated and determined, and it is determined whether the value is within the specified range or not, so that the optical axis of the headlamp is directed upward. You can determine whether it is pointing downward, or even to the left or right. In addition, the optical axis of the headlamp can be determined by giving the above judgment result as a forward or reverse rotation command to a screwdriver unit attached to an industrial robot, and rotating the adjuster screw attached to the headlamp. Adjust so that it falls within the range. In this case, the determination result can be visually displayed to allow the operator to operate the adjuster screw. Embodiment FIG. 7 shows the entire inspection apparatus including the optical axis measuring device of the present invention, in which industrial robots 2 are installed on both sides of a vehicle body transport line by a transport device (not shown), corresponding to the left and right headlamps 1. In addition, a laser oscillation device 4 and a light receiving plate 5 are arranged in front of the industrial robot 2. 6 is a main controller, and 7 is a robot controller. The vehicle body 8 is positioned on a trolley 9 of the transport device, and when the trolley 9 reaches a predetermined inspection position, the
The whole thing is positioned and stopped. The industrial robot 2 is equipped with an electric screwdriver unit 10 at the tip of its robot arm, and a fourth
As shown in the figure, the adjuster screws 11 and 12 attached to the headlamp 1 are rotated.
Incidentally, the screw driver unit 10 is equipped with a pulse encoder 14 on a DC motor 13 serving as a drive source in order to manage the rotation angle of the adjuster screws 11 and 12 (see FIG. 10). As shown in FIGS. 8 and 9, the optical axis measuring device 3 has a slide base 16 mounted on a base 15, and a swing arm 17 rotatably supported by the slide base 16.
The slide base 16 slides on the guide rail 19 by the action of the cylinder 18, while the swing arm 17 swings between the measurement position _Q1 and the retreat position _Q2 by the action of the cylinder 20. A measuring head 21 is attached to the tip of the swing arm 17, and details of this measuring head 21 are shown in FIGS. 1 to 6. In FIGS. 1 to 6, 22 is the measurement head 2.
1 frame, and this frame 22 has three gauge sensors 23, 24, and 25 that are integrated with a dial gauge and a potentiometer, and each gauge sensor 23, 2
Three guide rods 26, 2 corresponding to 4, 25
7 and 28 are arranged. Each guide rod 2
6, 27, 28 pass through the frame 22 as shown in FIGS. 5 and 6, and guide plates 29, 30, 31 and pads 32, 33,
34 are integrally attached. Further, auxiliary rods 35, 36, 37 are protruded from the back sides of the guide plates 29, 30, 31, and these auxiliary rods 35, 36, 37 are inserted into holes (not shown) formed on the frame 22 side. There are instructions for insertion. And each guide plate 29, 30, 31
The corresponding gauge sensors 23, 24,
Twenty-five probes 38, 39, and 40 are in contact with each other. Therefore, each guide rod 26,2
The slide displacements of 7 and 28 are caused by the guide plate 29,
The displacement of each guide rod 26, 27, 28 is transmitted via gauge sensors 30, 31 to gauge sensors 23, 24, 25. A back plate 41 is provided on the back side of the frame 22.
A reflecting mirror 42 is attached to this back plate 41. The back plate 41 is the fifth
As shown in the figure, its upper end is connected to the rear end of the guide rod 27 via a spherical joint 43, and the rear ends of the remaining two guide rods 26 and 28 are in contact with the lower part of the back plate 41. The back plate 41 is always biased by a tension coil spring 44 so as to come into contact with the rear ends of the guide rods 26, 28, and the inclination of the back plate 41 changes depending on the amount of displacement of each guide rod 26, 27, 28 described above. will change. At the center of the arrangement of the three guide rods 26, 27, 28, another center rod 45 is provided as shown in FIG. This center rod 4
5 is provided with a pad 46 at its tip and biased forward by a coil spring 47, and furthermore, a dog 48 is attached approximately at the center in the longitudinal direction. There is a proximity switch 49 below the center rod 45, and this proximity switch 49 is turned on and off in accordance with the approach and separation of the dog 48 of the center rod 45.
OFF operates. Therefore, the proximity switch 49 of the center rod 45 allows each gauge sensor 23, 24, 25 to detect whether the contact point 38, 39, 40 is correctly pressed against the lens surface P, as will be described later. Detection means is configured. Note that a linear sensor such as a potentiometer may be used as this detection means. Next, the operation of the optical axis inspection device as described above will be explained in the 10th section.
This will be explained with reference to FIGS. Incidentally, as shown in FIG. 2, boss portions B may be formed at three locations on the lens surface P of the headlamp 1 as polished surfaces. Therefore, in this embodiment, the inclination of the lens surface P of the headlamp 1 is detected by pressing the pads 32, 33, and 34 against the boss portion B. As mentioned above, until the vehicle body 8 is positioned at a predetermined inspection position, the slide base 16 of the optical axis measuring device 3 waits at the re-advancement limit position on the base 15, and the swing arm 17 also moves to the retracted position shown in FIG. position
It's in Q ₂ . When the vehicle body 8 is positioned at a predetermined inspection position,
As the swing arm 17 swings to the measurement position _Q1 , the slide base 16 starts to move backward. The slide base 16 has pads 32, 33, 34, and 46 of the measuring head 21 in contact with the lens surface P of the head lamp 1, and the center rod 4
5 moves backward until the proximity switch 49 is turned on. In other words, the ON operation of the proximity switch 49 means that the relative positional relationship between the lens surface P of the headlamp 1 and each gauge sensor 23, 34, 25 has become a predetermined measurable state. The slide base 16 is stopped and positioned. Note that if the proximity switch 49 does not turn ON even after the slide base 16 has retreated a predetermined amount, it is likely that the vehicle body has been pulled off the line in the previous process, so subsequent operations may be difficult. is not carried out. Further, a command is given to the industrial robot 2 to apply the screwdriver unit 10 to the adjuster screw 12 (FIG. 4) for adjusting the horizontal angle of the headlamp 1. In this case, although the position of the adjuster screw 12 differs depending on the vehicle type, the position data of the adjuster screw 12 for each vehicle type is given to the industrial robot 2 based on the vehicle type signal. When the screwdriver unit 10 is set in the correct position, the outputs B _s and C _s of the gauge sensors 23 and 25 are A/D converted and input to the CPU 50, while the head lamp type (for example, whether it is a halogen lamp or not) and the Since unique correction data for each vehicle type is stored in advance in the memory 51 according to the shape, etc., the correction data D _b and D _c corresponding to the gauge sensors 23 and 25 are taken into the CPU 50 . Then, X _h corresponding to the horizontal inclination of the headlamp 1 is determined based on equation (1), and it is determined whether the value of X _h is within a specified range. X _h = (B _s , C _b ) − (C _s + D _c ) ...(1) If the value of X _h is within the specified range, "Left and right direction OK" will be displayed and the screwdriver A command is given to the unit 10 to rotate the adjuster screw 12 by N rotations, and the value of X _h is adjusted to approximately the center value within the specified range. In other words, since the screwdriver unit 10 uses the DC motor 13 with the pulse encoder 14 as its driving source, by setting the specifications as shown in Table 1, the rotation angle per pulse is 360° ÷ 50.
= 7.2°. Also, adjust the screw pitch of the adjuster screw 12 attached to the headlamp 1 by 1 mm.
In this case, the amount of movement per pulse is 1mm ÷ 50
=0.02mm.

[Table] Therefore, screwdriver unit 1
By giving a predetermined amount of rotation command to 0, fine optical axis adjustment can be performed. Thereafter, in preparation for adjusting the optical axis of the headlamp 1 in the vertical direction, the industrial robot 2 applies the screw driver unit 10 to the adjuster screw 11 for vertical adjustment. On the other hand, if the previous value of X _h is outside the specified range _, then
Determine whether the value of deviates from the specified range in the positive direction or in the negative direction, that is, whether the optical axis, which correlates with the inclination of the head lamp's head lamp, is to the right or to the left. , accordingly gives a command to the screwdriver unit 10 to rotate clockwise or counterclockwise. In this case, the value of X _h is better as it is closer to zero, so X _h
The above cycle is repeated until the value is within the specified range. Regarding vertical optical axis adjustment of the headlamp 1, calculate the value of V _h based on equation ₍ 2),
The adjuster screw 11 is rotated until the value falls within the specified range. A _s is the value of the gauge sensor 24, and D _a is the correction data. V _h = (B _s + D _b ) + (C _s + D _c ) / 2 - (A _s - D _a ) ...(2) Then, when the optical axis adjustment in the vertical direction is completed, the adjustment is completed first. Since the horizontal position may have changed, check again whether both the horizontal and vertical directions are within the specified range. If both are within the specified range, select “All”.
"OK" is displayed, and the industrial robot 2 returns to the home position, and the swing arm 17 returns to the retracted position. On the other hand, if at least one of them deviates from the specified range, the adjustment must be repeated from the beginning, and a counter counts the number of times the adjustment is repeated. When the number of repetitions reaches the household number N, there is a high possibility that adjustment is not possible due to an abnormality in the installation of the headlamp itself, so "adjustment not possible" is displayed and the process ends. Next, the operation of the laser oscillation device 4 shown in FIG. 7 will be explained. As shown in FIG. 7, the laser beam L _a output from the laser oscillation device 4 is set in advance to be reflected by the reflecting mirror 42 of the measurement head 21 . On the other hand, the reflecting mirror 42 is tilted following the displacement of the guide rods 26, 27, and 28, that is, the inclination of the lens surface P of the headlamp 1, as shown in FIGS. Then, as mentioned above, when the optical axis of the headlamp 1 is within the specified range in both the vertical and horizontal directions, the reflected light of the laser beam L _a is received by the light receiving plate 5, and the actual measurement data of the optical axis is read. .
This measured data is stored as a unique value for each vehicle body.
Stored. Effects of the Invention According to the present invention, since the measuring head is directly pressed against the lens surface of the headlamp and the optical axis position is measured based on the inclination of the lens surface, a large space is secured unlike the conventional method. This eliminates the need for high-precision optical axis measurement with small-scale equipment, and also reduces the time required for optical axis measurement.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the measuring head, Fig. 2 is a view taken in the direction of arrow B in Fig. 1, Fig. 3 is a view taken in the direction of arrow A in Fig. 2, Fig. 4 is a left side view of Fig. 2, Figure 5 is a sectional view taken along line C-C in Figure 4, and Figure 6 is a cross-sectional view taken along line D-C in Figure 4.
7 is a plan view of the optical axis inspection device including the measuring device of the present invention, FIG. 8 is an enlarged view of the optical axis measuring device of FIG. 7, and FIG. 9 is a diagram of the optical axis measuring device of FIG. 8. The left side view and FIG. 10 are circuit diagrams of the optical axis measuring device, and FIGS. 11 and 12 are flowcharts of optical axis measurement and adjustment operations. 1... Head lamp, 3... Optical axis measuring device, 8
... Vehicle body, 21 ... Measuring head, 23, 24, 2
5... Gauge sensor, 38, 39, 40... Measuring head, 45... Center rod (detection means), 4
8...Dog, 49...Proximity switch (detection means),
P... Lens surface.

Claims (1)

[Scope of Claims] 1. A device for measuring the optical axis position of a headlamp based on the inclination of the lens surface by pressing a measuring head against the lens surface of a headlamp mounted on a vehicle body, the measuring head comprising: A contact sensor that detects the inclination of the lens surface by coming into contact with at least three measurement points on the lens surface, and a contact sensor that is provided in the center of the area surrounded by the three measurement points and that detects the direction in which the sensor is pressed. Detection means for confirming and detecting that the contact point of each sensor is pressed against the lens surface based on the slide displacement when the center rod contacts the lens surface. A headlamp optical axis measuring device characterized by: