JPH04367384A - Cutting/welding method for metallic plate by laser beam - Google Patents

Abstract

PURPOSE:To efficiently execute cutting and welding of a metallic plate by a simple mechanism by cutting end parts of both metallic plates to be joined, gripped by a clamp, with a laser beam and executing laser welding along a weld line prepared by butting both these end parts. CONSTITUTION:End parts of metallic plates M1, M2 gripped by clamps C1, C2, respectively are cut by moving laser beam cutting torches Tc1, Tc2 in the width direction, respectively. An output of a laser light in that case is, for instance, about 1KW for a 3mm soft steel plate, and oxygen gas is supplied as assist gas. Subsequently, the clamp C2 is moved toward the clamp C1 direction, and by butting both cut end parts, a weld line L is formed. Also, by allowing a back bar B to abut on the lower face of both the metallic plates, the welding preparation is completed. Thereafter, welding is executed by moving a laser beam welding torch Tw along the weld line L, while supplying a filler wire F. An output of a laser light in that case is, for instance, about 5KW for a 3mm soft steel plate, and helium gas is supplied as assist gas.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting and welding the ends of metal plates such as hot-rolled steel plates and pickled steel plates for continuous threading.

0002

[Prior Art] Such continuous metal plate threading is described in "Tetsu to Hagane 71 No. 14 (1985) P1677-P1
684, the ends of the two metal plates to be joined are brought together, and welding is performed by moving a laser welding torch along the joining line while supplying filler wire if necessary. The ends for welding were cut mechanically using a double cut shear or the like to form a butt line.

However, the clearance and lap distance of the shear blade used for such mechanical cutting cannot be easily changed once set to a certain clearance or lap distance, and therefore it is difficult to obtain a highly accurate cutting condition. In this case, the range of types and thicknesses of metals to be cut is extremely limited. Therefore, there is a problem in that sufficient cutting accuracy cannot be obtained when cutting plates made of many types of steel and of different thicknesses.

In order to solve the problems caused by mechanical cutting, for example, Japanese Patent Publication No. 3-20312,
“Tetsu to Hagane 71 No. 14 (1985) P159
Cutting using a laser is known as described in 9.

[0005] Laser cutting has the advantage that not only can the above-mentioned problems of conventional mechanical cutting be solved, but also that special large-scale attached equipment is not required.

[0006]

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for efficiently performing butt welding of metal plates such as hot rolled steel plates using a simple mechanism when using laser cutting. .

[0007]

[Means for Solving the Problems] In the laser cutting and welding method of metal plates of the present invention, both metal plates to be joined are held by respective clamps, and two laser cutting torches placed between the two clamps are used. , while maintaining their relative positions, move the metal plates in the width direction, cut the ends of both metal plates, then butt the ends of the metal plates, and run a laser welding torch along this butt line. It is characterized by moving to form a weld line.

Further efficiency can be achieved by using one of the two laser cutting torches used for cutting as the welding torch.

[0009]

[Operation] By cutting the ends of both jointed metal plates held by a clamp with a laser beam, the output of the laser beam and the flow rate of assist gas such as oxygen can be changed even if the type or thickness of the metal plate changes. This makes it possible to always obtain a highly accurate cut surface and perform butt welding using the same laser generation equipment.

Moreover, such laser cutting can prevent the generation of blowholes due to the dissolution of oxygen, etc. in the metal near the cut surface, and since both cutting and welding are performed by laser, filler wire may be added if necessary. This makes it possible to form clean welds.

[0011]

【Example】

Embodiment 1 FIG. 1 shows the procedure in a first embodiment of cutting and welding according to the present invention.

(a) of the same figure shows the preceding metal plate M to be joined.
1 and the laser torch Tc for cutting the metal plate M2
1 and Tc2, the respective torches Tc1 and Tc2 are connected to the clamps C1 and C2.
The tail end of the metal plate M1 held by the metal plate M
2 are placed at regular intervals, facing the tip.

Next, in step (b), the laser cutting torches Tc1 and Tc2 are moved in the width direction of both metal plates M1 and M2 to cut the ends of both metal plates. At this time,
The output of the laser light from both torches is approximately 1 kW when the metal plate is a mild steel plate with a thickness of 3 mm, and oxygen gas is supplied as the assist gas.

[0014] As shown in (c), the clamp C
2 in the direction of the clamp C1 to form a butt weld line L, and at the same time, apply the back bar B to the lower surfaces of both metal plates to complete welding preparation.

Thereafter, as shown in FIG. 3(d), welding is performed by moving the laser welding torch Tw along the welding line L while supplying the filler wire F. At this time, when the metal plate is a mild steel plate with a thickness of 3 mm, the laser light output of the torch is approximately 5 kW, and helium gas is supplied as the assist gas.

Embodiment 2 FIG. 2 shows a second embodiment of the present invention in which a cutting laser torch is used as a welding torch.

In FIG. 1(a), as in the case of FIG. 1(a), the tail end of the preceding metal plate M1 and the tip of the next metal plate M2 are held by clamps C1 and C2, respectively, and a torch for laser cutting and welding is held. Tcw and laser cutting torch Tc are arranged at a constant interval.

Next, in step (b), the ends of both metal plates are cut by moving both torches Tcw and Tc in the width direction of both metal plates.

Then, as shown in (c), the clamp C2 is moved in the direction of the clamp C1 to form a butt weld line L, and at the same time, the back bar B is applied to the side opposite to the welding torch of both metal plates to prepare for welding. complete.

Thereafter, as shown in (d), the position of the cutting/welding torch Tcw is first adjusted in the longitudinal direction of the metal plates so that it is centered on the butt line, and the welding line is adjusted while supplying the filler wire F. Move along L and perform welding.

[0021]

[Effects of the Invention] The following effects can be obtained by the present invention.

(1) Since cutting conditions can be set using easily controllable items such as laser light output and assist gas flow rate, accuracy can be maintained even if the type and dimensions of the metal plate to be cut or welded change. A good cut surface can be easily obtained automatically.

(2) Since cutting and welding are both performed using a laser torch, equipment that requires high rigidity such as a mechanical shear is not required, and the equipment can be made smaller and lighter.

[Brief explanation of the drawing]

FIG. 1 shows each step of a first embodiment of the present invention.

FIG. 2 shows each step of a second embodiment of the present invention.

[Explanation of symbols]

B Back bar C1 Clamp C2 for the first metal plate Clamp L for the second metal plate Welding line M1 First metal plate M2 Second metal plate Tc1 Laser cutting torch Tc for the first metal plate
2 Laser cutting torch Tw for the second metal plate
Laser welding torch Tc Laser cutting torch

Claims (2)

[Claims] Claim 1: Both metal plates to be joined are held by respective clamps, and two laser cutting torches placed between the two clamps are moved in the width direction of the metal plates while maintaining their relative positions. , after cutting the ends of both metal plates, the ends of the metal plates are abutted, and a laser welding torch is moved along the abutment line to form a weld line. Cutting and welding methods. 2. Holding both metal plates to be joined with respective clamps, moving two laser cutting torches placed between the two clamps in the width direction of the metal plates while maintaining their relative positions, After cutting the ends of both metal plates, the ends of the metal plates are butted together, and one of the laser cutting torches is also used as a welding torch along this butt line, and it is moved in the width direction to form a weld line. A method for cutting and welding a metal plate using a laser, characterized by forming a metal plate.