JPH0450105B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a laser welding device suitable for precision machining of minute parts.

Conventional configurations and their problems In recent years, laser welding has come to be used significantly for precision machining of minute parts.

A conventional laser welding device will be explained below.

FIG. 1 shows a processing section of a conventional laser welding device. 1 is a laser beam oscillated by a processing laser oscillator, 2 is a processing lens that focuses the laser beam 1, 3 is a protective glass for preventing damage to the processing lens 2, and 4 is the processing lens 2 and the protective glass. 3 is a lens holder that serves as a passage for the laser beam 1, and 5 is a spacer. 6 is a sheet metal part, and 7 is a shaft part, both of which are examples of workpieces. 8 is smoke generated from the workpieces 6 and 7 during welding, and 9 is spatter, which is an example of flying objects.

A conventional laser welding device configured as described above will be explained.

First, a laser beam 1 oscillated by a processing laser oscillator passes through a lens holder 4, is focused by a processing lens 2, passes through a protective glass 3, and is focused. Part 7 is reached and welding is performed. At this time, depending on the material or surface treatment of the sheet metal part 6 and the shaft part 7, evaporation and flying objects such as smoke 8 and spatter 9 are often generated, and it is impossible in principle to prevent these from occurring. Then, the smoke 8 and spatter 9 rise and adhere to the lower surface of the protective glass 3, blocking the transmission of the laser beam 1, reducing the output of the laser beam 1 on the processed surfaces of the sheet metal parts 6 and shaft parts 7, and causing melting. The problem is that the condition deteriorates and the bonding strength decreases, resulting in incorrect welding.
In addition, especially in mass production, smoke 8 may be added to the protective glass 3.
If spatters 9 adhere to the protective glass 3, the protective glass 3 must be periodically or arbitrarily inspected and cleaned or replaced in order to prevent welding errors, resulting in time loss and quality problems. Not only that, but it also caused a negative effect on productivity, which was a major problem.

OBJECT OF THE INVENTION The present invention solves the above-mentioned conventional problems by preventing evaporation of smoke and spatter and adhesion of flying objects to the protective glass, and preventing the laser beam from adhering to the processing surfaces of sheet metal parts, shaft parts, etc. The purpose is to achieve and maintain stable welding conditions without reducing output, thereby improving quality and productivity.

Structure of the Invention The present invention includes a processing laser oscillator, an optical system for condensing a laser beam, a protective glass for preventing damage to the processing lens, a nozzle provided on the lower surface of the protective glass, and an air or non-condensing an active gas supply device, the nozzle is provided with a gas inflow hole and an inflow hole, and the hollow part of the nozzle is shaped to widen on the workpiece side, and the gas from the supply device is provided with a gas inflow hole and an inflow hole of the nozzle. The gas flow prevents smoke and spatter generated from the workpiece during welding from evaporating and from adhering to the bottom surface of the protective glass. By preventing this, it is possible to provide a stable welding condition, maintain a good condition at all times, and improve welding quality and productivity.

DESCRIPTION OF THE EMBODIMENTS FIGS. 2 and 3 are cross-sectional views of a nozzle in an embodiment of the present invention. In FIG. 2, reference numeral 10 denotes an inflow hole 11 with an angle that allows air or inert gas to be blown directly onto the lower surface of the protective glass, a hollow part whose cross-sectional shape widens on the workpiece side, and an outflow hole 12. A nozzle having: In FIG. 3, reference numeral 13 designates an inflow hole 14 through which air or inert gas can be blown along the lower surface of the protective glass, a hollow portion whose cross-sectional shape widens toward the workpiece, and an outflow hole 15. It is a nozzle with

In addition, FIG. 4 shows the second laser welding device of the present invention.
It is a figure which shows the cross section of the processed part when the nozzle 10 shown in the figure is used. In FIG. 4, 16 indicates the flow of air or inert gas, and 17 is a supply device for air or inert gas.

The laser welding apparatus of this embodiment configured as described above will be explained.

First, a laser beam 1 emitted from a processing laser oscillator passes through a lens holder 4, is focused by a processing lens 2, passes through a protective glass 3, and is focused. reached and welded. At the same time or continuously, the supply device 1
Air or inert gas is supplied from 7 to the inflow hole 11, flows along the lower surface of the protective glass, and forms a kind of curtain. Then, a part flows out from the outflow hole 12, and a part flows out along the inner slope of the nozzle 10 in a direction away from the processing section, or flows out as a kind of vortex flow. Therefore, the evaporation and flying objects such as smoke 8 and spatter 9 generated from the sheet metal parts 6 and shaft parts 7 during welding are removed by the flow of air or inert gas formed by the cross-sectional shape of the nozzle 10, and the protective glass is removed. The particles can be scattered in the direction away from the processing area without rising towards the processing area. Furthermore, even if the spatters 9 rise to the vicinity of the protective glass 3, the curtain of air or inert gas formed on the lower surface of the protective glass 3 prevents the spatters 9 from adhering to the lower surface of the protective glass 3. It can be prevented.

In addition, in FIGS. 2 and 3, if the outflow holes 12 and 15 are not provided, the flow of the supplied air or inert gas will be greatly disturbed, and the smoke 8 and spatter 9 may be drawn into the lower surface of the protective glass. many,
It has been found through experiments that this causes interference with the transmission of the laser beam 1.

As described above, according to this embodiment, the nozzle of the laser welding device has a hollow section having an inflow hole and an outflow hole for air, inert gas, etc., and whose cross section widens on the workpiece side. By providing this, it is possible to effectively prevent evaporation and flying debris generated from the workpiece from adhering to the protective glass for preventing damage to the processing lens due to the gas flow.

Effects of the Invention The present invention provides a processing laser oscillator, an optical system for condensing a laser beam, a protective glass for preventing damage to the processing lens, a nozzle provided on the lower surface of the protective glass, and an air or an inert gas supply device, the nozzle is provided with a gas inflow hole and a gas outflow hole, and the hollow part of the nozzle is shaped to widen on the side of the workpiece, and the gas from the supply device is provided with a gas inflow hole and an outflow hole of the nozzle. By configuring the gas flow to flow in from the outflow hole and out from the hollow part, the gas flow prevents evaporation and flying debris generated from the workpiece during welding from adhering to the bottom surface of the protective glass, resulting in a stable flow. It is possible to provide and maintain the welding condition. Furthermore, there is no need to clean or replace the protective glass, making it possible to realize an excellent laser welding device that not only improves quality but also improves productivity.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the processing part of a conventional laser welding device, FIG. 2 is a sectional view of a nozzle in one embodiment of the present invention, FIG. 3 is a sectional view of a nozzle in another embodiment, and FIG. 4 1 is a cross-sectional view of a laser welding device in one embodiment of the present invention. 2... Lens for processing, 3... Protective glass, 1
0,13... Nozzle, 11... Inflow hole, 12...
Outflow hole, 17...supply device.

Claims (1)

[Claims] 1. A processing laser oscillator, an optical system that focuses the laser beam, a protective glass to prevent damage to the processing lens, a nozzle provided on the bottom surface of the protective glass, and an air or inert gas supply device. The nozzle is provided with a gas inflow hole and a gas outflow hole, and the hollow part of the nozzle is shaped to expand on the side of the workpiece, and the air or inert gas from the supply device is provided in the nozzle inflow hole. inflow,
A laser characterized in that a curtain of the air or inert gas is formed on the lower surface of the protective glass, and the air or inert gas is configured to flow out from the outlet hole and the hollow portion toward the workpiece. Welding equipment.