JPS61169188A - Cutting and welding method using laser beam - Google Patents

Abstract

PURPOSE:To prevent defective processing by passing a gas such as air between two sheets of materials facing each other or irradiating laser light thereto or disposing an object which absorbs the laser light thereto. CONSTITUTION:The laser beam 2 is condensed onto a square pipe 5 to form holes 6 on the surface. The gas 8 such as air, nitrogen, argon or CO2 is passed in large volume through an aperture 7 of the pipe 5 during the processing of the holes. The swarf 9 produced by the processing with the laser light 2 is discharged through the aperture 10 by the gas 8 and the pipe 5 is satisfactorily processed with the holes on the rear side without the swarf 9. An iron plate 11 which reflects the laser light 2 is other wise disposed in the pipe 5 and the pipe is processed with the holes by the laser. The plate 11 reflects irregularly the laser light past the holes 6 thereby preventing the injury of the pipe 5. The defective processing is prevented by such method.

Description

[Detailed description of the invention] [Industrial application field]

This invention uses a laser beam to produce a shape in which materials (plates, etc.) face each other vertically or horizontally, such as a box-shaped material, a pipe-shaped material (square, round, etc.), or a U-shaped material. This relates to a method for performing processing such as cutting, drilling, welding, etc.

[Conventional technology]

It is already a well-known fact that carbon dioxide lasers and YAG lasers are used for processing such as cutting, drilling, welding, and heat treatment of metals and nonmetals. When processing using a laser beam, such as cutting or drilling, normally when the workpiece is metal, oxygen gas is blown into the material coaxially with the laser beam, while when processing non-metals, , spray with air or nitrogen. Similarly, when welding metals, welding is performed by blowing an inert gas such as argon gas or helium gas coaxially with the laser beam. In the process of drilling or cutting using a laser beam, a hole is formed in the workpiece when drilling, and a groove is formed when cutting. Go through. Also, when welding thin plates with perfect predication, welding progresses while forming a tiny hole called a keyhole, so a certain percentage of the laser beam passes through to the back side. In this process, cutting, drilling, and welding are performed well, but when processing the box-shaped material or pipe-shaped material, the beam that passes through the back side may not match the processed material. It hits the opposing plate and melts or damages that part. Alternatively, at the same time, cutting powder from the material of the processed part may accumulate near that part, causing similar damage or significantly reducing the commercial value of the material.

[Problems to be solved by the invention]

Figure 5 shows a conventional example of making a large number of small holes on the -F side of a U-shaped material. Make a small hole (3) on the top. However, immediately after the hole (3) was formed, the laser beam (
2) passes through the hole (3) and is irradiated onto the lower material;
Damaged areas (4) such as holes and melting are formed in the irradiated area. For this reason, the conventional method has a problem in that good processing cannot be achieved and product defects occur frequently. This invention was made to solve the above-mentioned problems, and aims to provide a method that can perform stable cutting, drilling, welding, etc. without damaging opposing materials.

[Means to solve the problem]

The method according to this invention is one of the following five methods.
The above problem is solved by using more than one. That is, this method prevents damage caused by direct laser beam irradiation and reduces or eliminates cuts that adhere to the back surface. ■ Flow a gas such as air, nitrogen, argon, or CO2 gas between the two plates.

[Effect]

■ Place an object that reflects or absorbs laser light between the two materials. ■ Apply an oil film or a non-spatter welding material to the surface of the material opposite to the side to be processed. ■ Fill the space between the two plates with a gas that easily absorbs the laser beam. The figures will be described as an example of the implementation. Figure 1 is a diagram explaining the effect of the above (■), and shows the square pipe (
When forming (cutting) a square hole (6) by concentrating the laser beam (2) on the material surface in 5), use the square pipe (5).
In the prior art, by flowing a large amount of air (8) through the opening example, the chips (9) adhering to the back side can be expelled from the other openings 00. This allows for good hole machining with almost no chips on the back side. Although air is used as the gas in FIG. 1, other gases such as nitrogen, argon, and CO2 may also be used. Next, FIG. 2 is a diagram illustrating the effect of (2) above. A steel plate (11) is placed inside the square pipe (5) and a hole is machined using a laser beam (2), but all the laser beams that pass through the process are irradiated onto the steel plate α1). A part of the beam is absorbed by the iron plate (11), and the rest is reflected and diffusely reflected inside the square pipe (5), so that it does not damage the square vibrator. In addition, since the chips accumulate on the iron plate 01),
The inside of the pipe will not get dirty with chips. In Figure 2, a steel plate (11) is used as the material to be inserted inside, but a material that reflects the laser beam well, such as copper, may also be used, or an absorbing material such as firebrick, which absorbs most of the laser beam, may be used. Good too. FIG. 3 shows an example for explaining the effect of (2) above, in which an oil film (1
After applying 2), when cutting the square hole (6) with a laser beam, chips are difficult to adhere to the oil film, so
Product damage can be reduced. In FIG. 3, an oil film 02 is applied, but a non-sputter coating material used in arc welding or the like may be used. However, the non-sputter coating material needs to be removed later. Fig. 4 is an example to explain the effect of (2) above, in which the hole is drilled after filling the inside of the square vibrator with a gas that strongly absorbs carbon dioxide laser, such as CO2 gas or sulfur hexafluoride gas. It is something. Normally, during hole drilling, the laser beam 2 passes through the cutting groove.
The laser beam passes through to the back side and is irradiated on the back side, but if the square pipe (5) is filled with a gas that strongly absorbs the laser beam, the intensity of the laser beam that has passed through it will decrease rapidly, causing damage to the back side (
For example, holes, discoloration and melting) are eliminated. Finally, the above ■ is similar to the above ■, and the above ■
This is the action of blowing away the chips, and the above item (2) is the same effect obtained by sucking them in. The above embodiments have been explained only when making a square hole in a square pipe, but the workpiece is not limited to a square pipe, but can also be a round pipe with two or more pieces of material, such as a U-shaped or box-shaped pipe. Applicable to all opposing shapes. Furthermore, the processing contents are not limited to square holes, but can be applied to general hole processing such as micro holes and round holes, as well as cutting and welding, with exactly the same effect. Furthermore, the processing materials can be generally applied to non-metallic materials such as plastics and wood, and metallic materials such as iron plates.

【Effect of the invention】

As described above, according to the present invention, one or more of the above items (1) to (4) are combined to process the material using a laser beam, so that the opposite side of the material to be processed is not damaged. This has the effect of allowing defect-free machining.

[Brief explanation of drawings]

1 to 4 are diagrams showing an example of hole processing using a laser beam according to an embodiment of the present invention, and FIG. 5 is a diagram showing an example of hole processing using a conventional method. In addition, in the figure, the same reference numerals indicate the same or equivalent parts. In the figure, (1) is the processed material, (2) is the laser beam, (1j
is an iron plate, and α2) is an oil film.

Claims (1)

[Claims] Two materials have a shape such that they face each other vertically or horizontally, and one side is cut by a laser beam,
Or in a method of processing such as drilling or welding, (1) flowing a gas such as air, nitrogen, argon, carbon dioxide, etc. between the two facing materials. (2) Placing an object that reflects or absorbs laser light between the two opposing materials. (3) Apply an oil film or apply a welding non-spatter material to the surface of the non-workpiece that faces the workpiece. (4) Filling the space between the two opposing materials with a gas that absorbs laser light. (5) Sucking the air between the two facing materials. A cutting and welding method using a laser beam that uses one or a combination of the following.