JPH04157077A - Laser beam narrow gap welding method - Google Patents

Abstract

PURPOSE:To perform narrow gap welding without generating arc blow by oscillating a laser beam projected on the inside of a narrow gap by reflection mirrors inserted into the same narrow gap to melt a gap side wall. CONSTITUTION:The laser beam 1 is condensed by a condenser lens or a parabolic mirror 2 and projected on the inside of the narrow gap by a couple of reflection mirrors 5 and 6 which are inserted into the narrow gap and set up there. The one mirror 6 of these couple of reflection mirrors 5 and 6 is oscillated 7 by a necessary angle so that the laser beam 1 can be projected on both corners of the bottom of the narrow gas. In accordance with the oscillation 7 of the laser beam 1, a welding wire 8 is then fed and weld metal 9 is formed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a laser beam narrow gap welding method.

[Conventional technology]

Conventionally, when manufacturing welded structures, narrow gap welding has been performed to improve welding efficiency, and narrow gap welding methods using MIG and MAG welding have been put into practical use, and even higher quality welding is required. When welding carbon steel, low alloy steel, etc., narrow gap welding using the TIC method has been put into practical use. However, when welding carbon steel, low alloy steel, etc., there is a risk of magnetic blowing and welding defects when welding thick plates. (Yes, and this prevents widespread practical use.)

[Problem to be solved by the invention]

The present invention was proposed in view of these circumstances, and
Narrow gap welding can be performed without causing magnetic blow regardless of material type and magnetic properties G, and the side walls of the narrow gap can be reliably heated and melted to produce a sound welded part without weld defects. It is an object of the present invention to provide a laser beam narrow gap welding method that can form a narrow gap.

[Means to solve the problem]

To this end, the present invention is characterized in that the laser beam irradiated into the narrow groove is swung by a reflecting mirror inserted into the narrow groove to melt the groove sidewalls.

[Effect]

In the laser beam narrow gap welding method of the present invention, the laser beam is applied to the material of the object to be welded.

Since it has nothing to do with magnetic properties, it is possible to accurately irradiate a focused beam onto a targeted position.

In addition, by swinging the reflector inserted into the narrow gap by the required angle, the laser beam can be directed toward the side wall.
The groove sidewall can be reliably melted by irradiation.

Note that in order to guide the laser beam into the groove, it is preferable to use a beam with a large depth of focus that is focused using a long focal length lens or a parabolic mirror.

〔Example〕

An embodiment of the laser beam narrow gap welding method of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing the implementation procedure, and FIG. 2 is a front view thereof.

In FIGS. 1 and 2, a laser beam 1 is a laser beam that is sufficiently thin and long (with a large depth of focus) to irradiate into a narrow groove 4 having a depth and width corresponding to the thickness of a workpiece 3. In order to do this, the light is focused by a focusing lens or a parabolic mirror 2.

The focused laser beam 1 is inserted into the narrow gap 4 and is reflected by a pair of reflections @5. 6 irradiates the inside of the narrow gap 4. One of the reflecting mirrors 6 of this pair of reflecting mirrors 5.6
In order to irradiate both corners of the bottom of the narrow groove 4 with the laser beam 1, the swing 7 is performed by a necessary angle.

Then, welding is performed by feeding the welding wire 8 in accordance with the oscillation 7 of the laser beam 1, and the weld metal 9
is formed.

Thus, according to this welding method, the laser beam 1 can heat and melt the narrow gap 4 of the workpiece 3 regardless of the type of material or magnetic properties, so it can Narrow gap welding of materials that are prone to welding defects due to blowing is possible.

In addition, since the laser beam is oscillated 7 within the narrow groove 4 by the reflecting mirror 5.6, the side walls of the groove can be reliably melted and a sound weld metal 9 can be formed. (No need to take a large bevel angle for thick plates)
.

〔Effect of the invention〕

In short, according to the present invention, the laser beam irradiated into the narrow groove is swung by a reflecting mirror inserted into the narrow groove to melt the groove sidewalls, regardless of the type of material or magnetic properties. Laser beam narrow gap welding allows narrow gap welding to be performed without causing magnetic blow, and also reliably heats and melts the groove sidewalls of the narrow gap to form a sound weld without welding defects. Because you will find a way
The present invention is extremely useful industrially.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view showing an embodiment of the laser beam narrow gap welding method of the present invention, and FIG. 2 is a front view thereof. DESCRIPTION OF SYMBOLS 1... Laser beam, 2... Focusing lens or parabolic mirror, 3... Work to be welded, 4... Narrow gap, 5...
Reflector, 6... Reflector, 7... Swing of the reflector 6, 8
...Welding wire, 9...Welding metal. Figure 1 Figure 2

Claims (1)

[Claims] A laser beam narrow gap welding method characterized in that a laser beam irradiated into the narrow gap is swung by a reflecting mirror inserted into the narrow gap to melt the groove sidewalls.