JPH0245958B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser cutting method for cutting a workpiece with a laser beam.

[Conventional technology]

FIG. 3 is a cross-sectional view for explaining a conventional laser cutting method. A first cylindrical body 2 of the laser processing machine through which the laser beam 1 passes is bent at a right angle at the center, and a total reflection mirror for reflecting the laser beam 1 is attached to this bend. This first
A second cylinder 4 is screwed onto the tip of the cylinder 2, and a condenser lens 5 for focusing the laser beam 1 is disposed within the second cylinder 4. Further, a through hole 7 is provided protruding from the condenser lens 5 of the second cylindrical body 4 on the workpiece 6 side.
Gas is supplied into the cylinder 4.
Furthermore, a small diameter nozzle 8 is provided at the tip of the second cylinder 4.
A workpiece 6 is placed in front of this nozzle 8 and processed by the laser beam 1 with high energy density.

Next, the operation will be explained. As shown in FIG. 3, the laser beam 1 is bent by a total reflection mirror 3 so as to be irradiated perpendicularly to the workpiece 6. As shown in FIG. The bent laser beam 1 is focused by a condenser lens 5, and is irradiated onto a workpiece 6 through a nozzle 8. At this time, by moving the workpiece 6 as shown by the arrow, the workpiece 6 can be cut into an arbitrary shape. Further, the gas introduced through the communication port 7 is injected onto the workpiece 6 through the nozzle 8, and the molten or vaporized metal is removed by this gas.

In this cutting method, the workpiece 6 has a low viscosity of molten metal such as carbon steel or molten oxide generated when oxygen is used as a gas.
There is no problem in this case, but the situation is completely different when the workpiece 6 is made of stainless steel, aluminum, or the like, where the viscosity of the molten metal is extremely high.

FIG. 4 shows a cross section of a cut portion when a workpiece 6 of high viscosity molten metal is cut by such a method, and 9 is a cutting groove. In this case, no matter how appropriately the laser output, processing speed, etc. are controlled, the molten metal 10 will adhere to the back surface of the lower part of the cutting groove 9, and this molten metal 10 cannot be easily removed.

[Problem that the invention seeks to solve]

As mentioned above, in the conventional cutting method, the cutting groove 9
The molten metal 10 tends to adhere to the back surface of the lower part of the
Post-processing is required to remove them. This increases the number of processing steps and processing costs, which is a major problem especially in laser cutting of workpieces 6 such as stainless steel and aluminum.

The present invention was made to solve the above-mentioned conventional problems, and aims to provide a laser cutting method that can easily prevent the adhesion of molten metal, is extremely inexpensive, and has excellent product precision. This is what I did.

[Means for solving problems]

In the present invention, when cutting a workpiece made of a material with high viscosity of molten metal, a mixture of alcohol, graphite, and powdered clay is applied to the lower back surface of the workpiece, and a laser beam is irradiated onto the workpiece. It is designed to be cut.

[Effect]

A mixture of alcohol, graphite, and powdered clay was applied to the back side of the workpiece to prevent the metal melted by the laser beam from directly adhering to the backside of the workpiece, and the mixture was removed after processing. do.

〔Example〕

FIG. 1 is a sectional view for explaining an embodiment of the present invention, and portions indicated by 1 to 5, 7, and 8 are completely the same as the conventional example shown in FIG. 6a is a workpiece, the back surface of which is coated with a kneaded material 11 of alcohol (for example, methanol), graphite, and powdered clay.

When the workpiece 6a whose back surface is coated with the kneaded material 11 as described above is irradiated with the laser beam 1 and cut, the kneaded material 11 becomes metal melted by the laser beam 1, as shown in FIG. Since this prevents molten metal from directly adhering to the back surface of the workpiece 6a, processing can be performed without molten metal adhering to the back surface of the workpiece 6a. Note that even if molten metal adheres to the kneaded material 11, it can be easily removed by removing the kneaded material 11.

In the example, graphite and powdered clay were mixed at a ratio of 9:1 by weight, this mixture and methanol were kneaded at a ratio of 1:1 by weight, this kneaded product was applied to the back side of the workpiece, and the laser beam was applied to the back surface of the workpiece. When cutting with a beam, very good results were obtained.

〔Effect of the invention〕

As is clear from the above description, the present invention applies a kneaded mixture of alcohol, graphite, and powdered clay to the back side of a workpiece, irradiates the surface of the workpiece with a laser beam, and applies a mixture of alcohol, graphite, and powdered clay to the back side of the workpiece. Since the workpiece is cut, processing can be performed without molten metal adhering to the back surface. As a result, not only can highly accurate products be obtained, but the step of removing molten metal after laser processing can be omitted, and the kneaded material is extremely inexpensive, and moreover, it can be easily washed with water after processing. This method has great effects, such as being able to remove kneaded materials.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the laser cutting method according to the present invention, FIG. 2 is a cross-sectional view showing the shape of a cut surface when a workpiece is cut by the laser cutting method of the present invention, and FIG. 4 is a cross-sectional view showing a conventional laser cutting method, and FIG. 4 is a cross-sectional view showing the shape of a cut surface when a workpiece is cut by the conventional laser cutting method. In the figure, 1 is a laser beam, 2 is a first cylinder, 3 is a total reflection mirror, 4 is a second cylinder, 5 is a condensing lens, 6a is a workpiece, 7 is a through hole, 8 is a nozzle,
9 is a cutting groove, and 11 is a kneaded material. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A method of cutting a workpiece with a laser beam, in which a mixture of alcohol, graphite, and powdered clay is applied to the back side of the workpiece, and the surface of the workpiece is irradiated with a laser beam. , a laser cutting method characterized by cutting this workpiece. 2. The laser cutting method according to claim 1, wherein methanol is used as the alcohol. 3 The kneaded material was mixed with graphite and powdered clay in a weight ratio of 9:
1. The laser cutting method according to claim 1, wherein the mixture and methanol are kneaded at a weight ratio of 1:1.