JPS6284888A - Method and device for cutting welding by laser - Google Patents

Abstract

PURPOSE:To improve the welding efficiency, and to reduce the cost of a device by melting an object to be worked, by irradiating laser beam from one side of the object to be worked, in an inert gas atmosphere, and subsequently, executing the welding by irradiating the laser beam to its melted part from the other side. CONSTITUTION:The aperture 3 for insertion of an object to be worked W is provided on one side face which is opposed, of a working chamber 1, and also, in accordance with the aperture 3, a movable device 4 is provided on the upper and the lower parts. Also, an aperture 6 for moving a pair of laser working heads 5a, 5b is installed to the other opposed side face of the working chamber 1, respectively. The object to the worked W is inserted into the working chamber 1 from the aperture 3, and melted successively in an inert gas through the first working head 5a. Subsequently, the melted surfaces of the object to be worked W are butted and a laser welding is executed by the second working head 5b. The cutting welding is executed in an inert gas atmosphere by one set of laser beam machine, therefore, the cost of device is reduced and the welding efficiency can be improved.

Description

[Detailed description of the invention] [Technical field of invention] In this invention, a workpiece is cut by laser.

The present invention relates to a laser cutting and welding method for welding the fused portion using a laser, and an apparatus therefor.

[Technical background of the invention and its problems]

Generally, when a workpiece made of a steel plate or the like is cut with a laser, the cutting is performed in the atmosphere using oxygen as an assist gas. Therefore, an oxide film is formed on the cut surface. Therefore, when laser welding is performed by abutting cut surfaces with oxide films formed in this manner, cracks and bubbles occur in the welded portion, reducing the mechanical strength of the welded portion. In order to prevent such a decrease in mechanical strength, it is possible to cut the material with a laser, remove the oxide film on the cut surface, and then weld it.
This method cannot be said to be advantageous in terms of production since one additional step is required. Therefore, conventionally, when welding with a laser, the workpiece is cut by a mechanical method such as jarring or cutting, and the cut surfaces are butted together and welded. However, since such a method requires machining equipment that is different from laser welding, not only does the equipment cost increase, but it is also difficult to expect much improvement in production efficiency.

[Purpose of the invention]

The purpose of this invention is to perform cutting and welding with one laser processing device, thereby making it possible to perform welding with high mechanical strength efficiently.

[Summary of the invention]

In an inert gas atmosphere, the part to be cut is irradiated with laser light from one side of the workpiece to fuse it, and then the part to be cut is irradiated with laser light from the other side of the workpiece to weld. This eliminates the factors that reduce the mechanical strength of the weld, and makes use of the dross that occurs at the edge of the weld on the laser irradiation side during fusing.

This enables efficient welding with high mechanical strength.

In addition, the equipment for carrying out this cutting and welding includes a processing chamber configured to be able to be replaced with inert gas, a moving device that moves the workpiece to a fixed position in the processing chamber, and a machine that moves the workpiece to a fixed position in the processing chamber. A first machining head is installed on one side of the workpiece, and irradiates a laser beam emitted from a laser oscillator to a portion of the workpiece to be cut to fuse it, and a first processing head is installed on the other side of the workpiece. a second machining head that welds the welded part of the workpiece by irradiating it with a laser beam from the opposite side; By configuring it with an optical system that leads to two processing heads.

This makes cutting and welding using a laser more efficient.

[Embodiments of the invention]

Hereinafter, the present invention will be described based on embodiments with reference to the drawings.

FIG. 1 shows the configuration of a laser cutting and welding device which is an embodiment of the present invention. This laser cutting and welding device is equipped with a cubic-shaped processing chamber ω, and a workpiece (W) is removably inserted into the processing chamber (υ) on one opposing side of the processing chamber ω, as shown in FIG. There is an opening (■) reinforced by a caul plate (■) that can be used.

Corresponding to the width (2), a moving device for supporting and guiding the workpiece (W) and moving it to a fixed position within υ is provided at the upper and lower parts of the processing chamber ω. Also,
On the other opposing side of the processing room (G).

An opening 0 is provided through which the pair of laser processing heads (5a) and (5b) can be moved in the vertical direction. The pair of laser processing heads (5a), (
5b) can be independently moved along this opening 0 by a drive device (not shown), and each opening 0 is always shielded by the slide cover attached to these laser processing heads (5a) and (5b). It is now possible to do so.

Of the pair of laser processing heads (5a) and (5b).

A processing head (
5a) is a first processing head for cutting the workpiece (W), and a processing head (5a) provided on the other side of the workpiece (W) facing the first processing head; 5a)
is a second processing head for welding the workpiece (W).

Each processing head (5a), (5b) is provided with a nozzle (9) at the tip protruding into the processing chamber (υ),
From this nozzle (9), a laser beam is emitted which is reflected by a folding mirror (10) provided in the rear end located outside the processing chamber α) and then focused by a condensing lens (11). It has become. In addition, these processing heads (5a
), (5b) are pipes (1) slidably penetrating the processing chamber wall and connected to each processing head (5a), (5b).
Inert gas such as argon supplied from 2) is discharged from the nozzle (9) to replace the air in the processing chamber (1) with the inert gas.

The laser beam is oscillated from a laser oscillator (not shown) and guided to the first processing head via a folding mirror (13), and the second processing head is placed on the path of the laser beam oscillated from the laser oscillator. It is guided via a movable folding mirror (14) which is removably inserted.

Next, a method for cutting and welding workpieces will be described.

First, as shown in Fig. 3(A), a pair of workpieces (W, ) and (w2) to be cut and welded are placed in a processing chamber (
1) is inserted into the processing chamber (1) through the opening (2) provided on one side facing each other, and the part to be cut of one workpiece (W machining) is moved to the first processing head using the moving device r11 (A). Move and position it so that it faces you. - Release an inert gas from the power cylinder 1 processing head or the first and second processing heads to replace the air in the processing chamber α) with the inert gas. Thereafter, as shown by the broken line in FIG. 1, the movable folding mirror (14) is moved backward to guide the laser beam emitted from the laser oscillator to the first processing head via the folding mirror (13). By moving the first processing head,
The workpiece (W,) is fused and cut along the broken line (15a) in FIG. 3(A) with the laser beam (L) irradiated from this processing head.

Next, as shown in figure (B), the workpiece (wl) is moved backward by the moving device 0), and the melted end is taken out of the processing chamber (1). At the same time, the workpiece (2) is moved and positioned so that its cutting leg faces the first processing head. Then, the workpiece is cut along the broken line (15b) in the same way as the workpiece is cut by melting.

After the workpiece (S2) is moved back and the melted tip is removed from the processing chamber ■, the workpiece (S2) is removed as shown in figure (e). The respective melted surfaces are moved to butt each other, and the abutted portions are positioned so as to face the second processing head.

Thereafter, the movable folding mirror (14) is moved forward to the position shown by the solid line in FIG.
Guide to the processing head. By moving this second machining head, the laser beam (L) emitted from this machining head is applied to the workpieces (w, ) and (Wz) mentioned above.
Irradiate from the opposite side of the processing head to weld the butt portion.

Note that this welded workpiece is then transferred to the moving equipment VX (
b) is taken out of the processing chamber (1).

When a workpiece is cut and welded with a laser as described above, welding with high mechanical strength can be performed efficiently and easily. That is, conventionally, a workpiece made of, for example, a steel plate was cut in air using oxygen as an assist gas.

An oxide film forms on the cut surface and if it is used for welding as is.

The oxide film causes cracks and bubbles, making it impossible to weld with high mechanical strength.In order to increase the mechanical strength, cutting had to be done by mechanical processing such as jarring. In the above method, since cutting is performed in an inert gas atmosphere, a film such as an oxide film that deteriorates mechanical strength is not formed, and therefore welding with high mechanical strength can be performed. Moreover, since cutting and welding are all done by laser processing, efficiency can be greatly improved compared to conventional methods.

Moreover, the laser cutting and welding method in this invention is
By irradiating a laser beam from one side of the workpiece and fusing it, dross (16) is generated at the edge of the fused surface on the opposite side to the laser beam irradiation side, as shown in Fig. 4, and then Since the dross (16) is irradiated with a laser beam from the side of the dross (16) and welded using the dross (16) as a filler, the required welding can be performed even without supplying filler.

Further, the laser cutting and welding device of the present invention performs cutting and +8 welding with one device, and the high 1a laser processing device is used for multiple purposes, so the equipment cost can be reduced.

Next, other embodiments will be described.

In the above embodiment, an example was shown in which a workpiece consisting of a pair of plates was cut and welded.
) and (B), the workpieces (V
a), (15b), and weld the fused surfaces against each other as shown by the solid line (17), or as shown in Figures 6 (A) to (C), Both sides of the workpiece (W) consisting of a body are melt-cut to a predetermined size along the broken line (18), and the melted surfaces are brought together to form a tubular body (19).
This can also be applied to the case where the abutted portions are made into 28-touch lines to form a seam tube (20) as shown by the solid line (I7). In these cases, if the cutting is done from the inner surface of the tube or from the direction that will become the inner surface of the tube, welding will be done from the outer surface of the tube, and conversely, if the cutting is done from the outer surface of the tube or from the direction of the outer surface, the welding will be done from the outer surface of the tube. This is done from the inside of the tube.

Furthermore, as shown in FIGS. 7(A) and (8), the workpiece (litu) consisting of a pair of plates (w2) is indicated by the broken line (
15a).

It can also be applied to the case where fusing is performed as shown in (15b), the fusing edges where dross is generated due to this fusing are opposed, and edge welding is performed as shown in solid line (17).

Further, as shown in FIGS. 8(A) and 8(B), the workpieces (wx) and (W2) consisting of a pair of wires or rods are irradiated with laser light (L) from the side. broken fi (15a)
).

It can also be applied to the case where the welding is performed as shown by (15b), the fused surfaces are brought together and the laser beam (L) is irradiated from the opposite side, and welding is performed as shown by the solid line (17).

The present invention can also be applied to cutting and welding active metal materials such as titanium in addition to mild steel and stainless steel. Also, when welding relatively thick materials, it is optional to use filler together with dross, since undercuts are likely to occur.

〔Effect of the invention〕

In an inert gas atmosphere, the part to be cut is irradiated with a laser beam from one side of the workpiece to fuse it, and then the welded part is irradiated with a laser beam from the other side to weld. By eliminating the factors that reduce the mechanical strength of the weld and utilizing the dross generated by fusing, it has become possible to efficiently perform welding with high mechanical strength. Furthermore, since cutting and welding are performed using one laser processing device, the equipment cost can be reduced.

[Brief explanation of drawings]

FIGS. 1A and 1B are a front view and a side view, respectively, showing the configuration of a laser cutting and welding device according to an embodiment of the present invention, and FIG. 2 is a perspective view of its processing chamber, and FIG. 3
Figures (A) and (B) are process diagrams for explaining the laser cutting and welding method, and Figure 4 is a perspective view showing dross generated at the edge of the fused surface. Figure 5 (A) and (B), Figure 6 (A) or C
), FIGS. 7A and 7B, and FIGS. 8A and 8B are explanatory diagrams of other different embodiments of the present invention, respectively.

Claims (2)

[Claims] (1) A process of irradiating a laser beam to a portion to be cut of the workpiece from one side of the workpiece in an inert gas atmosphere to fuse it, and cutting the workpiece from the other side of the workpiece. A method for cutting and welding using a laser, comprising the step of irradiating a laser beam onto a fusing part to weld the fusing part. (2) A processing chamber configured to allow inert replacement, a moving device for moving the workpiece to a fixed position within the processing chamber, and a moving device configured to move the workpiece to a fixed position within the processing chamber, and a A first machining head is installed, and irradiates a laser beam emitted from a laser oscillator to a portion to be cut of the workpiece to fuse it, and a first machining head is installed on the other side of the workpiece positioned at a predetermined position in the machining chamber. a second processing head that is installed and welds by irradiating a laser beam oscillated from the laser oscillator to a fused portion of the workpiece that has been fused by irradiation with the laser beam from the opposite side; and an optical system that selectively guides the laser beam to the first or second processing head.