JPS6293093A - Weld line detecting device - Google Patents

Abstract

PURPOSE:To detect the position of a weld line without being affected by a rust, flaw, etc. by processing the weld line of the body to be worked to the binarization image in black and white and by removing the abnormal value from the measuring value by measuring the position which is from the base line of the weld line in plural places. CONSTITUTION:The reflecting beam irradiated on a weld line 25 is made incident onto the CCD camera 20 which is fitted to the welding head 5 of a beam welding machine. This optical signal is converted into an electrical signal and fed to a picture processor 23. The picture processor 23 projects the picture of the weld line 25 as the binarization image in black and white on a monitor TV 24. The dimension of the weld line 25 from the base line is measured by dividing this binarization image plurally. The dimension which varies too much from the other dimensions is removed by comparing the dimension at the distance 24a-24e from the base line. The effect of the flaw, rust, etc. 26 is removed for the detection of the weld line 25 by averaging the similar dimensions 24a, 24b, 24d, 24e.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a welding line detection device for a welding machine.

[Prior Art] Fig. 4 shows an example of a conventional weld line detection device disclosed in, for example, Japanese Patent Application Laid-open No. 57-149078.
r+I'l -r-dimension; n! E
Ii! /l 1. −? Tanyo A lis'l
If? I? Figure 6 is an enlarged perspective view of the main parts of the seat device, and is a waveform chart showing an example of a detected waveform of a weld line. Inside the processing chamber (1) there is a workpiece (2) and a processing table (3) for moving the workpiece (2).
is provided. Furthermore, the sliding mechanism (4) includes a welding head (5), a solid-state camera using a C0D (charged coupled device) image sensor (6), that is, a CCD camera (7), and a surface to be observed observed by a COD camera 7 (7). A light source (8) is provided for providing irradiation light.

The sliding mechanism (4) is installed between the machining chamber (1) by the electric motor (9) and the drive system (10) connected to it, and is positioned relative to the workpiece (2) through a sealing material Qll. The distance traveled is detected by the detector (2). (To) is an image processing device, C4 is a monitor television that monitors the image signal,
4 is the motor control panel.

Now, when strong illumination light is applied from the light source (8) to the welding joint of the workpiece (2), the reflected light from the observation surface is dark at the joint and bright at other parts. There, the CCD camera (7)
When you look at the relevant observation surface, a waveform as shown in FIG. 6 will be obtained on the monitor TV, depending on the RKK. In other words, the level (16a) indicates the high brightness portion, that is, the reflected light from the surface other than the seam, and the level (16b) represents the low brightness reflected light portion from the seam. Therefore, the troughs of the waveforms become welded seams.

[Problems to be Solved by the Invention] According to the conventional weld line detection device configured as described above, the position of the weld line can be measured, but the size of the gap between the bath tangents cannot be determined, and the measurement location cannot be determined. Since there is only one spot, there is a problem that if there are scratches, rust, etc. near the weld line, it is difficult to distinguish between the scratches, rust, etc. and the weld line. There is also the problem that when the bath tangent illumination device enters the objective lens obliquely, errors occur in the detection of the weld line due to the effects of shadows and the like.

The present invention was made to solve the above problems, and it measures the size of the gap between the bath tangents and determines the position of the weld line without being affected by scratches, rust, etc. near the weld line. The purpose of this invention is to obtain a welding line detection device that measures . Another purpose is to eliminate weld line detection errors due to the incident angle of the lighting device.

Means for Solving Problem 1] The present invention has been made to achieve the above object,
Image processing the welding line of the workpiece into a black and white binary image, measuring multiple positions of the processed welding line from the reference line, removing abnormal values from these measured values and only normal values. The present invention provides a weld line detection device that measures the size and position of a gap between weld lines by averaging the values using .

[Function] Detects the position of the weld line on the workpiece without being affected by rust, scratches, etc., and also detects the size of the gap between the weld lines and determines whether beam welding is possible.

〔Example〕

1 and 2 are a front view and a plan view showing an embodiment of the present invention. As shown in the figure, the welding head of the welding machine (5
) is attached with a tube θη for enlarging and photographing the weld line (c) of the workpiece (2), and the objective lens α &
There are four half mirrors near the center and a COD camera mount at the rear end. L: A lamp (21) is installed perpendicularly to the cylinder αη so that light hits the half mirror (to), and the brightness of this lamp (C) is adjusted by a power source (A). The CCD camera (4) is connected to the image processing device via a cable bundle, and the images taken are displayed on a monitor TV □□□. Figure 6 is an enlarged image of the welding line (A) shown on a monitor TV (C) in white and black, and shows scratches and rust on a part of the workpiece (2). etc. (24a) to (24e) are the distances of the welding line (a) from the reference line, and (24L+) to (24e)
4e) is the size of the gap between the welding lines (c).

A detailed explanation of the present invention configured as above is as follows. First, the CCD attached to the welding head (5)
The welding head (5) or the workpiece (2) is moved so that the welding line (c) of the workpiece (2) is in the field of view on the objective lens side of the camera. Bath tangent (c) to the field of view of the objective lens
When it turns on, turn on the lamp power switch and let the lamp (c) generate light. The light generated by the lamp 1) travels in the direction shown by the broken line (3), is reflected by the half mirror C9, passes through the objective lens 08, and reaches the welding line (3). The light that reaches the welding line - hits the surface of the workpiece (2) and is reflected, and the reflected light (solid line @) is reflected by the objective lens (toward).
, half mirror (to)? Pass through and enter the CCD camera (1). The optical signal of the image of the weld line entered by the CCD camera (a) is converted into an electrical signal and sent to the image processing device. The image processing device projects the image of the weld line onto a monitor television (c) as a binary image of white and black. The screen of the black-and-white binarized image displayed on the monitor television (c) is divided into, for example, five parts in the X direction, and the dimensions of the weld line from the reference line are measured. Its dimensions are shown in (24a) to (24e). Ma'r-
The measured dimensions of the gap between the weld line (c) are (24f) to (2
4j). By the way, in this case, the workpiece (2)
Scratches, rust, etc. on the surface (A) are considered to be welding (C). Therefore, the distance from the reference line (24C), C24h
) dimensions will cause errors in weld line detection. To prevent this error, the distance from the reference line (24a),
(24b), (24C).

Compare the dimensions of (24d) and (24e) and remove the dimension (24C) whose dimensions are even different from the other dimensions. In this way, the similar ivy dimensions (24a)-(24b),
Average only (24d) and (24e), @tangent (a)
For detection, remove the effects of scratches, rust, etc. (a).

(Effects of the Invention) As is clear from the above description, according to the present invention, the number of detected weld lines is measured in plurality and abnormal values are removed. In addition, it is possible to measure the size of the gap between the welding lines, and it is also possible to determine whether the workpiece can be welded, thereby preventing the production of defective products.In addition, the welding line can be illuminated by coaxial epi-illumination. Since it uses lighting, the equipment can be simplified.

[Brief explanation of drawings]

Fig. 1 is a front view showing an embodiment of the present invention, Fig. 2 is a plan view of Fig. 1, Fig. 6 is an enlarged view of the main part of Fig. 1, and Fig. 4 is an example of a conventional weld line detection device. FIG. 5 is an enlarged perspective view of the main part of FIG. 4, and FIG. 6 is a waveform diagram showing an example of a detected waveform of a weld line. (2)...Workpiece, (5)...Welding head, 08
...Objective lens, wire...COD camera,? Bu...
Lang, (c)...Lamp power source, kiln...image processing device, (c)...monitor television, (c)...welding wire. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Patent Attorney Tadashi Sato Year 23: ii'1lffJt i
Figure 3 Figure 4-5 Figure 1r Figure 6

Claims (1)

[Claims] (1) In a welding line detection device of a welding machine that welds a workpiece by irradiating a beam such as a laser beam or an electron beam to the workpiece through a welding head, the welding line of the workpiece is detected in black and white. The weld line can be determined by processing the image into a binary image, measuring multiple positions of the processed weld line from the reference line, removing abnormal values from these measured values, and averaging using only the normal values. A welding line detection device designed to measure the size and position of the gap.