JP2001212690A - Laser processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser processing method for protecting turning-up of an edge portion of a protection sheet that is cut and left on a processed work during a cutting processing. SOLUTION: A laser bam L is irradiated to a processed work 3 while gas is injected toward the processed work 3 through both of a gas passages 6 and 7 so that processed work 3 can be cut at a predetermined profile. Further, the processed work 3 is supported on a non-illustrated worktable so that a side of a protection sheet 5 on the processed work is in an upside position. Pressure of gas in a second gas passage 7 during a cutting processing is higher than the pressure of gas in a first gas passage 6. During a cutting processing, edge portions 5A, 5A of the protection sheet 5 at a cut place 3A is strongly pushed toward a base material 4 by gas of the second gas passage 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laser processing method, and more particularly, to a laser processing method for a workpiece whose surface is covered with a protective sheet.

[0002]

2. Description of the Related Art Heretofore, there has been known a method of irradiating a workpiece having a protective sheet attached to a surface thereof with a laser beam to cut the workpiece into a required shape. In such a conventional laser processing method, a workpiece is cut into a required shape by irradiating a laser beam while injecting an assist gas to a cutting processing position. For this reason, in the conventional laser processing method, when cutting is performed while supporting the workpiece so that the protective sheet is on the upper surface, the assist gas blown to the cutting position during the cutting process causes the position of the position already cut to be cut. It has been pointed out that the protective sheet is peeled up and turned up, and this comes into contact with the touch sensor to cause poor cutting. Therefore, a laser processing method that further solves such a defect has been proposed (for example, JP-A-2-295688 and JP-A-7-241688).
No.). That is, in the processing method disclosed in Japanese Patent Application Laid-Open No. 2-295688, a workpiece is irradiated with a laser beam through a special condenser lens having a flat surface and a convex surface. Thereby, the protective sheet is melted and evaporated by the laser beam condensed by the flat surface of the condenser lens, and at the same time, the inner side where the protective sheet is covered by the laser beam condensed by the convex surface of the condenser lens. The base material on the side is cut. On the other hand, in the processing method disclosed in JP-A-7-241688, a workpiece is irradiated with a laser beam to first burn a protective sheet on the surface of a base material so that the protective sheet does not peel off during the subsequent cutting. . After the protective sheet is baked on the surface of the base material in this way, the base material is irradiated with a high-output laser beam to perform necessary cutting.

[0003]

However, in the former processing method (Japanese Patent Application Laid-Open No. 2-295688), a processing head having a special condenser lens is required, which is required for laser processing. There was a disadvantage that the cost was high. On the other hand, the latter processing method described above (Japanese Patent Laid-Open No. 7-241688) has a drawback that the protective sheet is not easily peeled off when the protective sheet originally baked on the surface of the base material after the cutting is completed. was there.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides an inner nozzle which is disposed on the inner side and through which a laser beam passes, an outer nozzle provided surrounding the inner nozzle, and an inner nozzle. A first gas passage formed by the inner space of the first nozzle, a second gas passage formed in a space between the outer periphery of the inner nozzle and the inner periphery of the outer nozzle, and a first gas passage and a second gas passage. A gas supply source for supplying a gas, the workpiece having a protective sheet adhered to the surface thereof is supported such that the protective sheet faces upward, and the workpiece is processed via the first gas passage and the second gas passage. A laser processing method in which a workpiece is irradiated with a laser beam while injecting a gas into the workpiece to cut the workpiece into a required shape. Supply pressure to the first gas passage It is obtained by a high pressure than the pressure of that gas.

According to such a configuration, during the cutting process, the pressure of the gas in the second gas passage becomes higher than the pressure of the gas in the first gas passage located on the inner side. Therefore, the gas injected from the first gas passage flows downward through the cut groove of the workpiece cut by the laser beam. On the other hand, a part of the gas injected from the second gas passage flows inward, flows downward through the cut groove, and the other part diffuses outward. Therefore, the edge of the protective sheet adjacent to the cut groove is pressed against the surface of the base material of the workpiece by the gas injected from the second gas passage. Therefore, it is possible to prevent the edge of the cut protective sheet from being turned up during the cutting process.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, a processing head 1 of a laser processing apparatus is attached to a movable frame (not shown).
A condensing lens (not shown) for condensing the laser beam L is provided above the inside of the processing head 1. The processing head 1 is supported vertically downward, and a nozzle 2 is attached to a lower end of the processing head 1.
A processing table (not shown) is provided below the processing head 1, and a plate-shaped workpiece 3 is horizontally placed on the processing table. The workpiece 3 of this embodiment includes a plate-shaped stainless steel base material 4 and a vinyl protection sheet 5 attached to the entire surface (upper surface) of the base material 4. In this embodiment, the workpiece 3 is supported on a processing table such that the protection sheet 5 is on the upper side, and the workpiece 3 is cut. The laser processing device includes a laser oscillator (not shown). A laser beam L oscillated from the laser oscillator is guided to the processing head 1 by a plurality of reflecting mirrors (not shown), and then focused by a condenser lens. The workpiece 3 is irradiated through the lower end opening of the nozzle 2.

[0007] A movable frame (not shown) to which the processing head 1 is attached can be moved up and down by a lifting mechanism (not shown), and the movable frame and the processing table can be relatively moved on a horizontal plane. The nozzle 2 of the present embodiment includes a cylindrical inner nozzle 2A located on the inner side, and a cylindrical outer nozzle 2B provided to surround the inner nozzle 2A. The lower portion of the inner nozzle 2A and the outer nozzle 2B is formed in a tapered shape in which the lower end is reduced in diameter. In particular, the outer nozzle 2B
Is preferably installed so as to point in the vicinity of the inner working position. The inner space of the inner nozzle 2A is a first gas passage 6, and the annular space between the inner nozzle 2A and the outer nozzle 2B is a second gas passage 7. Further, the laser processing apparatus is provided with a supply source 11 of an assist gas (nitrogen), and this supply source 11 is connected to a first gas passage 6 of the processing head 1 via a first conduit 12. The first conduit 12 is provided with a first solenoid on-off valve 13, and the operation of the first solenoid on-off valve 13 is controlled by a control device (not shown). Note that the gas supply source 11 to be supplied to the first gas passage 6 and the gas supply source 11 to be supplied to the second gas passage 7 may be separately provided. The type of gas may be different.

The assist gas supply source 11 is
It is connected to the second gas passage 7 via a conduit 14.
The second conduit 14 is provided with a second electromagnetic on-off valve 15, and the operation of the second electromagnetic on-off valve 15 is also controlled by a control device (not shown). The first solenoid on-off valve 13 and the second solenoid on-off valve 15 have a pressure adjusting function, and the control device opens both of the on-off valves 13 and 15, and the respective gas passages 6 and 6 are controlled by the pressure adjusting mechanism provided therein. The pressure of the assist gas supplied to 7 can be adjusted. When the processing head 1 irradiates the workpiece 3 with the laser beam L to perform the cutting process, the control device opens the first electromagnetic on-off valve 13 and the second electromagnetic on-off valve 15.
The assist gas is injected from the lower end opening of the inner nozzle 2 to the cutting portion 3A of the workpiece 3 via the conduit 12 and the first gas passage 6. At the same time, the second conduit 14
The assist gas is supplied to the workpiece 3 at a position adjacent to the cutting portion 3A via the second gas passage 7 and the lower end opening. The pressure of the assist gas supplied to the first gas passage 6 and the second gas passage 7 is appropriately adjusted by controlling the operations of the first electromagnetic valve 13 and the second electromagnetic valve 15 by the control device. Can be. The above configuration is not different from that of a conventionally known laser processing apparatus.

In this embodiment, when performing the cutting, the pressure of the assist gas supplied to the second gas passage 7 is higher than the pressure of the assist gas supplied to the first gas passage 6 by the control device. The two electromagnetic on-off valves 13 and 14 are controlled so that As described above, in the present embodiment, the workpiece 3 is supported on the processing table so that the protection sheet 5 is directed upward, and cutting is performed into a required shape. Therefore, during the cutting, the assist gas in the second gas passage 7 has a higher pressure than the pressure of the assist gas injected into the first gas passage 6, so that the processing portion (cut groove) 3A by the laser beam L is used. Edge 5 of the protective sheet 5 located adjacent to the
The assist gas in the second gas passage 7 is injected from above toward the vicinity of A and 5A. Here, FIG. 2 is an enlarged view showing the flow of gas injected from both gas passages 6 and 7 to the processing location (cut groove) 3A. This figure 2
As shown in the figure, the gas G1 injected from the first gas passage 6
Flows downward through a processing location (cut groove) 3A of the workpiece 3 cut by the laser beam L. On the other hand,
A part of the gas G2 injected from the second gas passage 7 flows inward, flows downward through the processing location (cut groove) 3A, and the other part diffuses outward. It flows like so. Thereby, the edge 5 of the protection sheet 5
Since A and 5A are strongly pressed against base material 4, it is possible to prevent the edges 5A and 5A from being turned up.

In the above embodiment, the entire space between the inner nozzle 2A and the outer nozzle 2B is defined as the second gas passage 7. However, the following structure may be adopted. That is, as shown in a horizontal sectional view in FIG. 3, the plate-shaped member 21 is provided at a lower position in the nozzle 2 so as to close the space between the inner nozzle 2A and the outer nozzle 2B. Then, a plurality of through holes 21 surrounding the inner nozzle 2 </ b> A are formed in the plate-shaped member 21.
a may be provided. Also in such an embodiment, surrounding the assist gas injected from the first gas passage 6,
Assist gas can be injected from the lower end of the second gas passage 7 toward the workpiece 3. Further, in the above embodiment, plate-shaped stainless steel is used as the base material 4 of the workpiece 3, but the present invention is applicable to any workpiece in which the protective sheet 5 is attached to the surface of the base material 4. Can be cut and processed. Further, in the above-described embodiment, the case where the present invention is implemented by the laser processing device not provided with the touch sensor has been described. However, a laser processing device provided with a touch sensor that comes into contact with the surface of the workpiece may be used. . Further, in the above embodiment, both gas passages 6 and 7 are supplied from the same supply source 11.
Although nitrogen is supplied to the inside, the type of gas supplied to both gas passages 6 and 7 may be changed according to the material of the workpiece.

[0011]

As described above, according to the present invention, there is obtained an effect that the edge of the protection sheet cut at the time of cutting can be prevented from being turned up.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a gas flow in the main part of FIG. 1;

FIG. 3 is a horizontal sectional view of a nozzle showing another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Processing head 2 Nozzle 2A Inner nozzle 2B Outer nozzle 3 Workpiece 4 Base material 5 Protective sheet 6 First
Gas passage 7 First gas passage 11 Supply source

Claims (2)

[Claims] An inner nozzle disposed on an inner side through which a laser beam passes; an outer nozzle provided to surround the inner nozzle; and a first nozzle formed by an inner space of the inner nozzle.
A gas passage, a second gas passage formed in a space between the outer periphery of the inner nozzle and the inner periphery of the outer nozzle, a gas supply source for supplying gas to the first gas passage and the second gas passage, A workpiece having a protective sheet attached to the surface thereof is supported such that the protective sheet faces upward, and the workpiece is sprayed onto the workpiece via the first gas passage and the second gas passage while injecting gas to the workpiece. A laser processing method for irradiating a workpiece with a laser beam to cut the workpiece into a required shape, wherein the pressure of gas supplied to the second gas passage is reduced by the first gas passage. A laser processing method wherein the pressure is higher than the pressure of the gas supplied to the substrate. 2. The pressure of the gas supplied to the two gas passages is reduced so that a part of the gas injected from the second gas passage passes through the cut groove of the work to a lower side of the work. The laser processing method according to claim 1, wherein the adjustment is performed.