JPH02165888A - Laser beam machining method - Google Patents

Abstract

PURPOSE:To prevent the generation of an oxide film by irradiating a laser beam and executing cutting, while pushing aside a liquid by high pressure gas injected from a nozzle immersed into a liquid, at the time of bringing a work immersed into a liquid being in a no-oxygen state. CONSTITUTION:A laser beam LB oscillated by a laser oscillator 33 passes through an overhead beam member 39, a bend mirror device 37, and a bend mirror 43 in a Z axis carriage 21, and condensed by a lens in a working head 29. The beam irradiates a work W through the tip of a nozzle 31 and the work is cut. Water 39 of no-oxygen, etc., are put into a groove 3V of a base 3 and the work W and the tip of the nozzle 31 are also immersed into water. As for a distance between the surface of the work W and the nozzle 31, a prescribed distance is held by moving the working head 29 in the Z axis direction, and also, it is brought to position adjustment in the X axis and the Y axis directions. The laser beam LB irradiates the work W together with high pressure gas and executes cutting, while pushing aside a liquid by high pressure gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention 1 (Industrial Application Field) The present invention relates to a laser processing method for performing oxidation-free laser processing on a workpiece to be processed.

(Conventional technology) Conventionally, when cutting a workpiece made of stainless steel or steel using a laser beam, the laser beam is irradiated onto the workpiece, and nitrogen is used as an assist gas to cut the workpiece without oxidation. Conditions were created and a clean cut was performed.

In addition, since the cutting process uses the heat of the laser beam and the heat of the oxidation reaction, oxygen is used as an assist gas to lower the reflectance of the workpiece and improve absorption of the laser beam, resulting in non-oxidation cutting. was.

(Problem to be solved by the invention) By the way, in the conventional laser processing method described above, when nitrogen gas is used as the assist gas, the surface and cut surface of the workpiece become non-oxidized; The surface near the lower end of the cut surface is oxidized by air intrusion, causing backburn, which adversely affects welding and painting, and has a problem of deteriorating the aesthetic appearance.

In addition, when oxygen gas is used as the assist gas, a metal oxide film is formed on the cut surface, and furthermore, the vicinity of the cut portion, especially the back surface, is also discolored and deteriorated due to oxidation, which has an adverse effect on welding and painting, and reduces the aesthetic appearance. There was a problem with losses. Therefore,
In order to remove the negative effects caused by oxidation, an inert gas is used as the assist gas, and by appropriately setting the pressure, focus position, output, etc. of the assist gas, it is possible to remove the workpiece near the cut surface or the upper edge of the cut surface. Oxide film, deterioration, etc. on the surface, etc.
This prevented the occurrence of discoloration, etc.

However, since the back surface near the lower edge of the cut surface of the workpiece is in contact with air due to air being mixed in, there is a problem in that an oxide film is formed, which has an adverse effect on welding and painting, and also impairs the aesthetic appearance.

The purpose of the present invention is to improve the above-mentioned problems by immersing the workpiece to be processed into a liquid in an almost oxygen-free state to make the workpiece non-oxidized, thereby preventing the formation of an oxide film, deterioration, discoloration, etc. The object of the present invention is to provide a laser processing method that has the following advantages.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for cutting a workpiece immersed in an almost oxygen-free liquid using a laser beam. The nozzle provided at the tip of the processing head is immersed in the liquid, and while the surface of the workpiece and the tip of the nozzle are kept at a substantially constant distance, the liquid is swept away with high-pressure gas irradiated from the nozzle. This is a laser processing method that performs cutting by blowing a laser beam onto the workpiece.

(Function) By employing the laser processing method of the present invention, the workpiece to be processed is immersed in a liquid in an almost oxygen-free state, and
A nozzle provided at the tip of the processing head is also immersed in this liquid, so that the surface of the workpiece and the tip of the nozzle are maintained at a constant distance. In this state, the high-pressure gas irradiated from the nozzle sweeps through the liquid and blows it away, and the workpiece is irradiated with a laser beam, thereby shielding the workpiece from oxygen in the air, preventing oxidation, and performing oxidation-free cutting. As a result, good cutting quality is maintained.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

Referring to FIG. 1, a laser processing machine 1 includes a U-shaped base 3 that is open at the top and is disposed on, for example, a floor surface.

At the bottom of the U-shaped groove 3v of the base 3, a plurality of support columns 5 on which workpieces W made of stainless steel, steel, etc. are placed are erected.

On the upper surface of the support frames 3R, 3m integrated on both sides of the base 3, there are X-axis circumferential guide rails 7R, 7L extending in a direction perpendicular to the plane of the paper (hereinafter referred to as the X-axis direction) in FIG. It is laid down. Said base 3
An X-axis gear ledge 9 is provided above. This X
The shaft gear 9 includes frames 13R and 13L' which are provided with guide members 11R and 11L at the bottom thereof, which are guided by the X-axis guide rails 7R and 7L, and frames 13R and 13L.
It is composed of connecting frames 15U and 15D extending in the left-right direction (hereinafter referred to as the Y-axis direction) connecting the L.

With the above configuration, when the X-axis drive motor (not shown) is driven, the guide members 11R, 11L are guided by the X-axis circumferential guide rails 7R, 7L laid on the upper surface of the support frames 3R, 3L in the base 3, and the guide members 11R, 11L move. Therefore, the X-axis gearbox 9 is moved in the X-axis direction.

The connecting frames 15U, 15D are provided with Y-axis guide rails 17tJ, 17D extending in the Y-axis direction. This Y-axis circumference is the light rail 17U.

170 is provided with a Y-axis gearledge 19 that is guided by Y-axis layer guide rails 17LJ and 17D and is movable in the Y-axis direction. For example, on the left side of the Y-axis gear 19, a Z-axis gear 21 extending in the vertical direction (hereinafter referred to as the Z-axis direction) is provided.

The frame 13R is provided with a transmission member 23 that is operatively connected to a Y-axis drive motor (not shown). This transmission member 23 is provided with one end of a ball screw 25, and the other end of the ball screw 25 is supported by the frame 13L. A nut member 27 is screwed onto the ball screw 25, and this nut member 27 is connected to the Y-axis gear 1.
It is located in

With the above configuration, when the Y-axis drive motor (not shown) is driven, the ball screw 25 is rotated via the transmission member 23, so the Y-axis gear ledge 19 is rotated via the nut member 27.
is guided by the Y-axis peripheral guide rails 17U and 17D and moved in the Y-axis direction.

At the bottom of the Z-axis gear ledge 21 is a processing head 29 that is movable in the Z-axis direction by a Z-axis drive motor (not shown).
A nozzle 31 for irradiating a laser beam is provided at the lower end of the processing head 29.

With the above configuration, when the Z-axis drive motor (not shown) is driven, the processing head 29 moves in the Z-axis direction, and the position of the tip of the nozzle 31 provided at the tip of the processing head 29 and the top of the plurality of support columns 5 are adjusted. The distance from the surface of the workpiece W placed on the surface is adjusted.

A base 35 on which a laser oscillator 33 is mounted is disposed behind the base 3, for example on the right side. An over Radbeam member 39 is connected to the laser oscillator 33 and passes the laser beam LB to a pend mirror device 37 provided on the frame 13R.

Furthermore, the pend mirror device 37 and the two-axis carriage 21
An overhead beam member 41 is connected to the two-axis carriage 21, and a pend mirror 43 is provided within the two-axis carriage 21. The laser beam LLB oscillated by the laser oscillator 33 is transmitted to the overhead beam member 39. The light passes through the pend mirror device 37° over the Radbeam member 41 and the pend mirror 43 in the two-axis carriage 21, is focused by a condensing lens (not shown) provided in the processing head 29, and is further directed from the tip of the nozzle 31 toward the workpiece W. The workpiece W is cut by the irradiation.

As shown in FIG. 1, a substantially oxygen-free liquid 39 is placed in the groove 3 of the base 3, and the workpiece W is immersed in this liquid 39. The tip of the nozzle 31 is also immersed in the liquid 39. Furthermore, the distance between the surface of the workpiece W and the tip position of the nozzle 31 is always maintained at a constant distance, for example, about 0.3 to Q, 5 mm, by moving the processing head 29 in the Z-axis direction.

The liquid 39 is preferably water with low oxygen content, and more preferably boiled water, distilled water, or water to which a rust preventive has been added.In short, the liquid may be substantially oxygen-free.

With the above configuration, the work W is placed on the plurality of support columns 5, and the distance between the surface of the work W and the tip position of the nozzle 31 is kept constant, for example, about 0.3 to 0.5 mm. . In this state, the laser beam LB emitted from the laser oscillator 33 is irradiated onto the surface of the work W from the nozzle 31 provided at the tip of the processing head 29 together with a high pressure gas of, for example, about 10 ka/cm2, and the high pressure gas causes the liquid 3 A predetermined cutting process is performed by blowing the material while separating it. Furthermore, the processing head 29
By moving in the X-axis, Y-axis, and Z-axis directions, desired cutting is performed on each part of the workpiece W.

In this way, by immersing the workpiece W in the liquid 39 and cutting it with the laser beam L8, the workpiece W is shielded from oxygen in the air, preventing oxidation, and can be cut in an oxidized state. Therefore, it is possible to prevent the formation of an oxide film, deterioration, discoloration, etc. on the workpiece W, and to obtain a product that maintains good cutting quality.

Note that the present invention is not limited to the embodiments described above, and can be implemented in other embodiments by making appropriate changes. For example, in this embodiment, the laser beam processing machine 1 is of a type in which the workpiece W is fixed and the laser beam LB is moved, but the laser processing machine 1 is of a type in which the laser beam LB is fixed and the workpiece W is moved. is also possible.

[Effects of the Invention] As understood from the description of the embodiments above, according to the present invention, since the structure is as described in the claims, the workpiece is immersed in the liquid and the processing head is The nozzle provided at the tip is also immersed in the liquid, and cutting is performed while maintaining a constant distance between the surface of the workpiece and the tip of the nozzle, thereby shielding the workpiece from oxygen in the air and preventing oxidation. , cutting can be performed in a non-oxidized state. Therefore, it is possible to prevent the formation of an oxide film, deterioration, discoloration, etc. on the workpiece, and to obtain a product that maintains good cutting quality.

[Brief explanation of the drawing]

FIG. 1 is a front view of a laser processing machine according to an embodiment for carrying out the laser processing method of the present invention. 1... Rede processing machine 29... Processing head 3
1... Nozzle 39... Liquid agent Patent attorney Yasu Miyoshi Male 1... Laser processing machine 31... Nozzle 29... Processing head 39... Liquid Fig. 1

Claims (1)

[Claims] When cutting a workpiece immersed in an almost oxygen-free liquid using a laser beam, the nozzle provided at the tip of the processing head is immersed in the liquid, and the surface of the workpiece and the tip of the nozzle are A laser processing method characterized in that cutting is performed by irradiating a workpiece with a laser beam while blowing away the liquid with high-pressure gas irradiated from a nozzle while holding the workpiece at a substantially constant distance.