JPS61212493A - Welding quality detecting device - Google Patents

Abstract

PURPOSE:To increase the reliability in the inspection of welding quality by inspecting the height of URANAMI bead on weld zone using a non-contact type displacement gage. CONSTITUTION:A laser beam machine is provided so as to irradiate laser beam 1 on the one side of the bodies 3a, 3b to be worked. A non-contact type displacement gage 17 is arranged on the back side further and is made scan able with moving in the horizontal direction via a motor and ball screw. The quality of welding can be judged by inspecting whether the height of build up place of the URANAMI bead 4c in butt URANAMI weld is constant or not. Namely after completion of welding, the height is measured by scanning the displacement gage 7 along the URANAMI bead 4c. An inspection is then performed by comparing with the height of the back bead 4c in the case of non-defective good. The inspection having no effect of assist gas is thus enabled and the reliability in quality inspection is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a welding quality inspection device K11A in a laser processing device.

[Conventional technology]

FIG. 6 is an external view showing a conventional welding quality inspection method disclosed in, for example, Japanese Patent Publication No. 56-22639. In the figure, (1) is a laser beam, which is focused by a processing lens (2) and irradiated onto a workpiece (3).

(1) is the evaporation and melted debris of the workpiece generated during processing; (2) is an optical detector such as a photodiode equipped with a filter (2).

Next, the operation will be explained. A laser beam (1) is focused by a processing lens (2), and is irradiated onto a workpiece (3) to perform laser processing such as cutting and welding.

Since the scattered particles α of the workpiece (3) are heated to a high temperature by the laser beam (1), they output light when scattered. In laser processing, there is a difference in the amount of evaporated matter and molten material generated when the processing amount is optimal and when it deviates from this optimal processing amount, and in relation to this, there is a difference in the light emission time due to the heating of the flying object (11). There is a big difference.

By detecting the light emission time due to the heating of this scattered object a force with an optical detector a1 such as a photodiode installed with a filter (b) placed upside down outside the laser beam (1), it is possible to determine whether laser processing is optimal. Detect.

[Problem that the invention seeks to solve]

Conventional welding quality detection devices are configured as described above, and attempt to detect the quality of laser processing such as welding using the light generated by evaporated matter or molten matter scattered from the workpiece, but the scattered matter is Since the light is disturbed by the flow of assist gas inside, there is a problem in that the detection of light is unstable and the inspection of welding quality is unreliable.

This invention was made to solve the above-mentioned problems, and aims to provide a highly reliable welding quality detection device that is not affected by the flow of assist gas during welding.

[Means for solving problems]

The welding quality detection device according to the present invention is a laser processing device equipped with a non-contact displacement meter for detecting the height of the uranami bead in butt welding. The welding quality is determined by comparing the height of the uranami bead in butt uranami welding with the height of the uranami bead in a good weld, and measuring whether there is any abnormality using a non-contact displacement meter.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a front view of the embodiment according to the invention, and Fig. 2 is a side sectional view thereof. In the figure, (1) is a laser beam,
The light is focused by the processing lens (2)K.

(3a) and (3b) are workpieces to which butt butt welding is to be performed. (5) and (6) are clamps that fix the workpiece, (7) is a non-contact displacement meter with wheels that can be moved horizontally by an electric motor (9) and a ball screw α1, and a fixed guide plate (8). ) is maintained by.

(lη is a laser light source, (2) is a lens, (2) is a laser beam α → from the laser light source is reflected on the back bead (4c),
This is the imaging surface on which the lens (2) is rotated to form an image.

Next, the operation will be explained. A laser beam (1) extracted from an oscillator (not shown) is focused by a lens (2) and positioned on the line of abutment between the workpieces (3a) and (3b). The abutting portions of the workpieces (3a) and (6b) are welded by being irradiated with a focused laser beam. At that time, since the workpieces (3a) and (3b) are butt welded, the weld meat is on the surface bead (
Overlay part of 4a), base material part (4b), back bead (4C)
It consists of overlay parts. The degree to which this butt back welding has been completed can be determined by checking whether the height of the fleshy part of the back bead (4c) is constant.

Therefore, K that performs this judgment is a non-contact type displacement needle (7).
is scanned to measure the height of the bead (4C) after welding is completed. This embodiment shows a triangulation method using a laser beam as an example of a non-contact displacement meter. The beam (14b) is projected onto the imaging plane (to) through the lens (2), and the build-up height of the back bead (4c) is detected based on the position of the image.

As a result of detecting the height of the back bead (4c) with the non-contact detector (7) through the above operations, if the height of this back bead differs from the back bead height of a good workpiece, It outputs a signal indicating welding defects and inspects welding quality. At this time, the non-contact displacement meter (7) is moved horizontally by an electric motor (9) and a ball screw (toward) in order to measure the back bead height of the workpiece (3) over the entire width direction of the plate. It has become.

〔Effect of the invention〕

As described above, according to the present invention, since a non-contact displacement meter using a laser beam is used to detect welding quality, a highly reliable detection of welding defects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing a welding quality detection device according to an embodiment of the present invention, FIG. 2 is a side sectional view of FIG. 1, and FIG. 3 is an external view showing a conventional welding quality detection method. (1) is the laser beam, (3a) and (3b) are the workpieces, (4C) is the Uranami bead, and (7) is the non-contact displacement meter. In the figures, the same reference numerals indicate the same or equivalent parts. Agent Patent Attorney Sanro Kimura Figure 2

Claims (1)

[Claims] A welding quality detection device characterized in that in butt uranami welding using a laser processing device, the height of the uranami bead of the welded portion is measured using a non-contact displacement meter, and the welded portion is inspected.