JPS602959B2 - Laser processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the improvement of a nozzle of a processing head that jets assist gas to the processing section of a workpiece (workpiece material) when the processing section is irradiated with a laser beam. More specifically, the present invention relates to a laser processing device equipped with an injection nozzle for removing melted matter and evaporated matter generated during processing of a workpiece, and for ejecting a mixed assist gas that also serves as a cooling effect around the processing section.

Generally, the assist gas used during laser processing is oxygen (02), which can promote oxidation reactions.

However, since oxygen as an assist gas is expensive, it is not used as it is, but rather mixed with air. The mixing ratio of air and oxygen is selected depending on the type of workpiece, and gas cylinders with that mixing ratio are currently prepared in advance and replaced each time the type of workpiece changes.

By the way, conventionally, the required amount of oxygen can be adjusted depending on processing conditions such as the material of the workpiece, the processing speed, and the thickness of the arc. However, the type and mixing ratio of the mixed gas is determined by using a gas cylinder specified by the manufacturer in advance. However, there is a problem in that it is impossible for anyone other than a trader to freely adjust the mixing ratio of the mixed gas sealed in this gas cylinder as necessary, and the cost is high.

The present invention has been made to effectively solve these problems in the prior art, and its purpose is to provide a laser processing device that can freely adjust the mixture of assist gases and that can perform processing with high precision. It is something to do.

According to the present invention, this purpose is achieved by dividing the assist gas into the main assist gas and the sub-assist gas, and when injecting the main assist gas to the machining part of the workpiece, the main assist gas is provided in the injection passage. This is achieved by sucking the sub-assist gas from the suction passage so that the desired mixing ratio can be adjusted.

Hereinafter, preferred embodiments of the present invention will be described based on the accompanying drawings.

1 and 2 show a front view and a plan view of an NC-controlled laser processing apparatus according to the present invention, and this laser processing apparatus 1 mainly includes a laser processing machine 3 and a laser processing machine using a carbon dioxide laser. The workpiece W, which is composed of an oscillator 5, a power supply device 7 for the laser oscillator 5, and a cooling system (not shown) for cooling the oscillation mixed gas in the laser oscillator 5, is processed by the laser processing machine 3. N.C.
Positioned by control.

The laser processing machine 3 includes a plurality of mirrors 13a that irradiate a laser beam 4 (laser beam) 9 oscillated from a laser oscillator 5 onto a workpiece W layered on a fixed table 11, which is referred to as a table. 13b and 13c are attached so as to be adjustable.

Further, the entrusted laser beam 9 passes through a condensing lens 15a and a nozzle 15b provided in the processing head 15, and strikes the surface of the workpiece W or a processing portion slightly below the surface.
is focused and irradiated.

As a result, the workpiece W absorbs the optical energy of the laser beam 9, and the processed portion Z of the workpiece W is melted and evaporated, resulting in groove processing and
Cutting, welding, etc. are performed.

A positioning device 17 for gripping a plate-shaped workpiece W is provided on one side in the longitudinal direction of the fixed table ring 1.
A reference stopper in the direction is provided, and an x-mari carriage 21 that moves in the front-rear direction in FIG. 2 along the X-axis guide rail 19 is attached.

The X-axis guide rail 19 is a Y-axis (not shown) installed in the longitudinal direction (left-right direction in FIG. 2) of the fixed table 11.
It is placed on a Y-axis carriage 23 that moves along an axis guide rail.

The X-axis guide rail 19 and the Y-axis guide rail (not shown) are laid orthogonally, and the X-axis carriage 21 guided by the X-axis guide rail 19 is driven by a servo motor 25, and the The Y-axis carriage 23 guided by the rail is driven by a servo motor (not shown).

Reference numeral 27 denotes a moving table that is provided integrally with the Y-axis carriage 23. On this moving table 27, there are a plurality of free stroke bearings 2 that support the work W.
9 is rotatably buried.

Further, a reference stopper 31 in the X-axis direction is provided on the negative side of the moving table 27.
is provided so as to be able to appear and retract from the surface (bus line) through which the workpiece W passes.

A dust collector 33 is installed below the fixed table 11 to suck out slag, gas, etc. generated by laser processing, and this dust collector 33 is connected to a vacuum pump or the like (not shown). The nozzle 15b attached to the tip of the processing head 15 constitutes a so-called mixing nozzle 35, which serves as both the laser beam 9 irradiation nozzle and the assist gas injection nozzle, as described above.
The mixing nozzle 35 is composed of a cylindrical reference nozzle assembly 37 and a movable nozzle assembly 39, as shown in FIG. Further, a tapered nozzle portion 43 is formed at the bottom. The reference nozzle assembly 37 is hermetically screwed to the lower end of the processing head 15 via a threaded portion 41a at its upper end, and is fixedly held from the outside by a lock screw 45.

Further, the movable nozzle assembly 39 is screwed onto the outer circumferential portion of the basic nozzle assembly 37 via the threaded portion 41b, and the reference/zzle assembly 39 has a mixing injection nozzle portion 47 formed in its center. At the same time, an inlet 49 for the auxiliary assist gas is formed in the side wall.

A movable nozzle assembly 39 is attached to the reference nozzle assembly 37.
When screwed, there is an ejection passage 51 between the tip of the reference nozzle assembly 37 and the inner wall surface of the movable nozzle assembly 39, through which the laser beam 9 and the main assist gas G are ejected;
Branching from this jetting passage 51, the secondary assist gas G2
A suction passage 53 for the assist gas G2 is formed to communicate with the inlet 49 of the assist gas G2.

In this embodiment, compressed air is used as the main assist gas G, and oxygen is used as the sub assist gas G2.

In addition, the reference nozzle assembly 37 and the movable nozzle assembly 39
A sealing member 55, such as an O-ring, is interposed between the assist gas and the assist gas to maintain airtightness of the assist gas.

Further, the passage area of the suction passage 53Z for the secondary assist gas G2 can be adjusted as appropriate by rotating the movable nozzle assembly 39 with respect to the threaded portion 41b of the reference nozzle assembly 37.

The main assist gas such as the compressed air C. As shown in FIG.
5a is removed, and the flow rate is constantly measured by passing it through a flowmeter 61, and it is ejected from the nozzle part 43 via other necessary devices (not shown). Further, a sub-assist gas G2 such as oxygen is sent from a pressure supply source 63 such as an oxygen cylinder through a filter 65 to a pressure regulating valve 67, where the pressure is set lower than that of the main assist gas G.

The oxygen flow rate can be adjusted by a flow rate adjustment device 69 such as a throttle valve, the flow rate of the sub-assist gas G2 is constantly measured by a flow meter 71, and the entry of compressed air is controlled by a check valve 75 provided in a flow path 73. To prevent.
The sub-assist gas G2 ejected from the sub-assist gas inlet 49 into the suction passage 53 is sucked by the ejection pressure of the main assist gas G, which is ejected from the nozzle part 43 and the mixed injection nozzle part 47 through the ejection passage 51, It mixes with the main assist gas G and is ejected to the machining pattern of the workpiece W.

In addition, the secondary assist gas G2 with respect to the main assist gas G,
A switching valve (not shown) is provided in the flow path 53 to increase or decrease the ratio between the main assist gas G and the sub assist gas G2.
Furthermore, by inputting the flow rate of the main assist gas G, the flow rate of the sub-assist gas G2, and the machining conditions, etc. to an NC device (not shown), both can be set by the NC device itself. It is also possible to manage the mixing ratio of the assist gases G, , G2.

With such a device, the mixing ratio of the secondary assist gas G2 can be freely set from 20% to 100%.

As described above, according to this embodiment, when the main assist gas G is injected during laser processing, the sub assist gas G2 is
Since the assist gas is sucked in an appropriate amount and is injected into the processing portion of the workpiece W, it is possible to inject a mixed assist gas suitable for the material to be processed on the workpiece W.

As described above, the present invention provides a laser beam and a main assist gas ejection passage, as described in the claims.
The sub-assist gas intake passage is branched from this ejection passage and connected to the sub-assist gas intake passage, and when the main assist gas is ejected, the sub-assist gas is mixed by suction and injected from the mixing nozzle 35. This has the advantage that laser processing can be easily and inexpensively performed without using gas alone. In addition, the closing area of the secondary assist gas suction passage can be adjusted freely, so the mixture ratio of the assist gas can be adjusted according to the processing conditions and material of the workpiece, and the flow rate can also be adjusted. High-precision machining and high-speed machining can be performed.

In addition, according to the above embodiment, air is used as the main assist gas,
Although oxygen is used as the secondary assist gas, the present invention is not limited to this, and any gas may be used as long as it is a mixture of two gases, such as oxygen and nitrogen.

It should be noted that the present invention is not limited to the above-described embodiments, and may be implemented in other embodiments, and the numbers attached to the claims do not limit the technical scope.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a laser processing apparatus embodying the present invention, and FIG. 2 is a plan view of FIG. 1. FIG. 3 is an enlarged sectional view of the main part of the present invention.

Explanation of main symbols shown in the drawings: W... Workpiece, 15... Processing head, 15b... Nozzle, 9... Laser beam, 1... Laser processing device, 15b... Nozzle, 3
7... Reference nozzle assembly, 39... Movable nozzle assembly, G,... Main assist gas, 51... Ejection passage,
G... secondary assist gas.

Crowding map Figure 2 figure M the gunwale

Claims (1)

[Scope of Claims] 1. While irradiating the processing portion Z of the workpiece W placed on the table with the laser beam 9 from the nozzle 15b detachably attached to the processing head 15, assist gas is injected to generate the laser beam. In the laser processing apparatus 1 that performs processing, the nozzle 15b is composed of a reference nozzle assembly 37 and a movable nozzle assembly 39, and an ejection passage for the laser beam 9 and the main assist gas G_1 is provided inside the reference nozzle assembly 37 and the movable nozzle assembly 39. 51 and a suction passage 53 for sucking and ejecting the sub-assist gas G_2 in the middle of the ejection passage 51 are provided in communication with each other. 2 By moving the movable nozzle assembly 39 relative to the reference nozzle assembly 37, the secondary assist gas G
The laser processing apparatus according to claim 1, wherein the opening area of the suction passage 53 of _2 is adjustable.