JPS61235086A - Laser welding equipment - Google Patents

Abstract

PURPOSE:To obtain a laser welding equipment which can execute a laser welding exactly and with high accuracy by measuring a gap width in a butt part of the preceding plate and the following plate, by non-contact before welding, deciding whether its measured value is correct or not, and thereafter, executing the laser welding. CONSTITUTION:When steel is welded by a laser beam, a gap width G of a butt part of the preceding plate 15a and the following plate 15b is detected as a positive image by an optical detecting means (video camera) 20. Subsequently, from this positive image, the gap width G is calculated by an operating means 26, and the calculated gap width G is compared with a reference value by a comparing circuit 25 and decided. Also, in accordance with an output signal of the comparing circuit 25, a control for starting or stopping the welding is executed by a welder controlling circuit 27. As a result, a laser welding can be executed exactly and with high accuracy.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a laser welding device for welding steel using laser light. Laser welding device C: is designed to perform welding after detecting the inside of the gap.

[Conventional technology]

FIG. 6 is a plan view of a conventional laser welding device.

In FIG. 1, (4) is a moving block equipped with a duct for transmitting laser light from a laser oscillator (not shown);
(5) is a feed screw that moves the moving block (4), (
6) is the bearing of the feed screw (5), and the pair of supports (7),
(7) Supervision: Both ends of the installed crossbeam (8) (- are provided. CLO is the servo motor for rotating the feed screw (5), αB is the motor shaft 1 of the servo motor αG:
The fixed drive gear, (b) is one end of the feed screw (5) (
- A fixed gear that meshes with the drive gear (b). The targets are the side of the moving block (4) (2 installed processing heads, α4 is the bed, (15a) is the leading plate placed on the bed (b), (15b) is the trailing plate placed on the bed 041m board, αQ is the leading board (15a) and trailing board (15b)
) is the welding line.

A conventional laser welding device is configured as described above, for example, a leading plate (15a) and a trailing plate (15a) to be welded.
5b) The ends in the longitudinal direction, that is, in the direction of arrow X in FIG. 6, are butted against each other on one bed CI4.

Next (2) The butting part of the leading plate (15a) and the trailing plate (15b), that is, the weld line (9) C: Welding is performed by irradiating the laser beam emitted from the processing head 4. At this time, the servo motor is rotated, and the rotational force is transmitted to the drive gear (111,
The transmission is transmitted to the feed screw (5) via the gear (a), and the rotation of the feed screw (5) (: moves the moving block (4) in the direction of arrow Y in Fig. 6 (:), causing the moving block (4) c Welding is performed by moving the attached processing head (2) along the welding point αQ.

[Problem that the invention seeks to solve]

In the conventional laser welding apparatus as described above, the leading plate (15a) and the trailing plate (15b) are positioned and matched by a clamper on the bed plate 4.
15a) and the trailing plate (15d).
Although the gap amount is several tens of μm, it is impossible to judge whether it is an appropriate gap amount or not, and there is a problem that reliable and highly accurate welding cannot always be obtained.

This invention was developed in order to solve this problem, and the amount of gap at the abutting portion between the leading plate and the trailing plate is measured before welding (without contact), and the gap amount is determined by laser welding C2. To provide a laser welding device capable of performing reliable and highly precise laser welding by performing C laser welding after determining whether it is appropriate.

[Means for solving problems]

The laser welding apparatus according to the present invention includes an optical detection means for capturing an image of the abutting portion of a leading plate and a trailing plate to be welded, and an operation for calculating a gap amount from a normal image of the abutting portion imaged by the optical detecting means. means, a comparison circuit that makes a decision by comparing the gap amount calculated by the calculation means C2 with a preset reference value of the gap amount, and starts welding in response to a signal that is judged and outputted by the comparison circuit. The welding machine control circuit is configured to include a welding machine control circuit for starting and stopping the welding machine.

[For production]

In this invention, the optical detection means detects the gap amount at the abutting portion of the leading plate and the trailing plate as a correct image, the calculating means calculates the gap amount from the correct image, and the calculated gap amount is sent to the comparison circuit. The welding machine control circuit (2) performs control to start or stop welding based on the output signal (2) of the comparison circuit.

[Embodiment 1] FIG. 1 is a front view of a laser welding device showing one embodiment of the present invention, and FIG. 2 is a plan view of the laser welding device. Diagram C
2, the same components as those of the conventional example are given the same reference numerals and redundant explanations will be omitted.

Symbol (1) is a laser oscillator that emits a laser beam, (
2a) is an expandable beam transmission duct that transmits the laser beam, (2b) is a normal beam transmission duct, and (3) is a beam transmission duct that supports (2a) and (2b) and (=transmission that changes the optical path). The duct support member, αη is the laser beam emitted from the processing head (to), and the handle is the side part of the processing head (C): industrial video cameras installed in parallel, leading plate (15a) and trailing plate (15b). ).

FIG. 3 is a block diagram for detecting an abnormality in the gap of members to be welded by the laser welding device.

In Figure C2, (15a) and (15b) are the leading plate and the trailing plate to be welded, and G is the leading plate (15a) and the trailing plate (15
b) The gap at the butt part, Qη is an enlarging optical system that magnifies the image of the gap G, the wire is a binarization circuit that converts the normal image of the video camera into a binarized image, and the width of the gap G is 2 An arithmetic circuit that operates from the output signal of the value conversion circuit (A), (C)
is a CRT that displays the calculation results of the calculation circuit (2), (a)
(c) is a comparator circuit that compares and determines the value of the gap amount calculated by the arithmetic circuit (2) with a preset reference value of the gap amount, and (c) is an arithmetic means consisting of a binarization circuit gradient and an arithmetic circuit wire. , (a) is a welding machine control circuit that controls the processing head υ(: laser jj0 processing).

Next, the leading plate (15a) and the trailing plate (1
The operation for detecting an abnormality in the gap width of the gap G in the abutted portion in step 5b) will be described with reference to the block diagram in FIG. 5 and the broach yard in FIG. 4.

First, in step 100, the leading plate (15a) and the trailing plate (15b) to be welded on the bed 0 (1-1) are butted against each other to start. Next, in step 101, the matching of the leading plate (15a) and the trailing plate (15b) is completed.

Then, in step 102, the servo motor αa rotates to rotate the feed screw (5), and the movable block (4) accordingly moves in the Y direction (-), and the video camera mounted on the movable block (4) Move along the welding line CL0 between the leading plate (15a) and the trailing plate (15b), and perform gap GO scanning at the abutting part (==).In step 103, the video camera is installed: The image of the gap G is enlarged by the optical system ai>, and the enlarged normal image of the gap G is captured on the video camera.In step 104, the enlarged normal image of the gap G is sent to the binarization circuit (to ) (: Therefore, the binarized image C: is converted.

In step 105, the binarized image has a gap G of black,
Others indicate that the image will be white. At step 106,
The value of the black image portion corresponding to the gap Gc of the binarized image is calculated by C2 in the calculation circuit. In step 107, the calculation result of the gap G by the calculation circuit (to) C is CR
T(c)C: Display. In step 108, the comparison circuit (2
) compares the gap width value calculated by the arithmetic circuit - with a preset gap width reference value Rf, and determines that ζ is within the reference value.
It is determined in step 109 whether there are two.

Then, when the value of the gap width calculated by the calculation circuit (to) is within the reference value, a welding start signal is outputted to the comparison circuit as shown in step 110. Step 111
Now, the welding machine control circuit (2) that received the welding start signal
drives the servo motor αO (= processing head o
Welding is performed by step 3. That is, the servo motor (to) is driven to return the processing head (to) to the original position C: and then the servo motor (to) is driven again to move the processing head (to) to the feed wheel 17 (5).
) and move the processing head (2) in the Y-axis direction, turn on the laser oscillator (1) and send the laser beam emitted from the laser oscillator (1) to the beam transmission duct) (
2a), moving block (3), beam transmission duct) (2
b) from the processing head (2) to the preceding plate (15a
) and the trailing plate (15b) at the welding line αQ (:: irradiated and welded. Then, in step 112, welding is completed.

On the other hand, if the value of the gap width calculated by the calculation circuit 4 is within the reference value (2), the comparison circuit (to) outputs a welding stop signal as shown in step 116.In step 114, the welding stop signal is received. The welding machine control circuit (b) stops welding by the processing head a3C, and drives the butt servo motor (C) to weld the leading plate (15) again.
a) and the trailing plate (15b) are brought into alignment. The subsequent operation is step 102ζ; return.

Through the above operations, the laser beam can perform butt welding of steel plates with high precision and reliability.

In FIG. 5, the same components as in the second embodiment of the present invention are given the same reference numerals as in the conventional example, and redundant explanation will be omitted. In this example, two industrial video cameras (1) and a window are used, each of which has a rotating mechanism of opaque screws (5a) and (5b) that are separate from the feed screw (5). 1: It is configured so that it can be moved accordingly. Then, one video camera (A) images half of the abutting portion between the leading plate (15a) and the trailing plate (15b), and the other video camera (A) images the remaining half of the abutting portion and aligns the butt. It detects gaps across the county. In addition, each opaque screw (5a), (5b) is connected to a dedicated servo motor.
driven by.

Control of the gap width of the gap G imaged by each video camera is carried out in the same manner as in the first embodiment, so a description of the operation will be omitted.

This embodiment has the advantage that the scanning time is short because the two video cameras (a)-m detect each half of the gap at the abutting portion.

〔Effect of the invention〕

As described above (: According to this invention C), the gear tooth width at the abutting portion of the leading plate and the trailing plate is detected as a normal image by an optical detection means, and the gear tooth width is calculated from the normal image by a calculating means,
The comparator circuit compares the calculated gear tooth width with the reference value to determine the output signal C of the comparator circuit.The welding machine control circuit starts or stops welding accordingly. This has the effect of providing reliable and highly accurate welding results.

[Brief explanation of drawings]

Fig. 1 is a front view of a laser welding device showing an embodiment of the present invention, Fig. 2 is a plan view of the same laser welding device, and Fig. 6 is a method for detecting gap abnormalities in members to be welded by the laser welding device. 4 is a flowchart showing the operation of the block diagram, FIG. 5 is a front view of a laser welding device showing a second embodiment of the present invention, and FIG. 6 is a front view of a conventional laser welding device. In Figure ≦2, (15a) is the leading board, (isb) is the trailing board, so is the video camera (optical detection means), (a) is the binarization circuit, (to) is the arithmetic circuit, (e) is a comparison circuit, (2)
is the calculation means, and (support) is the welding machine control circuit. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Patent Attorney Kimura San Roki 1 Figure 2o, Pi Geo f IXte flood filial ≧ short chi to government) Figure 2 Figure 5 Figure 6

Claims (2)

[Claims] (1) Optical detection means that images the abutting part of the leading plate and trailing plate to be welded by a laser beam, and calculation for calculating the value of the gap width from the correct image of the abutting part imaged by the optical detecting means. The gap width value calculated by the calculation means is compared with a preset gap width reference value, and when the gap width value is less than the reference value, a welding start signal is output, and the gap width value is set to the reference value. A laser welding device characterized by comprising a comparison circuit that outputs a welding stop signal in the above cases, and a welding machine control circuit that starts welding based on the welding start signal of the comparison circuit and stops laser welding based on the welding stop signal. . (2) The calculation means converts the normal image of the butt portion of the leading board and trailing board into a binarized image of the gap and other parts2.
2. The laser welding apparatus according to claim 1, further comprising a digitizing circuit and an arithmetic circuit for calculating the value of the gap width output from the binarizing circuit.