JPS5987989A - Laser beam machine - Google Patents

Abstract

PURPOSE:To prevent dew condensation on the surface of an inclined plane mirror for changing the direction of laserlight right above a working table under a highly moist condition by separating the cooling stage of said mirror and the other cooling stage and interlocking the feeding and stopping of cooling water to said mirror to the transmission of the laser light. CONSTITUTION:The direction of laser light 2 transmitted from a laser oscillator 1 of a CO2 laser device is changed with aninclined plane mirror 6, and enters a machining head 3, from which the light is condensed by a lens to a work. An external part shielding mirror 5 movable from the point A-A to point A'-A' is provided between the oscillator 1 and the head 3, and the detectors 14, 15 of a mechanism for moving the mirror emit signals when the mirror 5 is at the above-mentioned respective points. A solenoid valve 9 is opened by the signal of the detector 15, then the cooling water flows in the mirror 5 to cool the mirror. A solenoid valve 10 is opened by the signal of the detector 14, then the cooling water flows in the mirror 6 to cool the mirror. The cooling water does not flow to the mirror through which the laser light is not transmitted and therefore the generation of dew condensation on account of the cooling on the mirror surface down to the dew point or below is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cooling method for a carbon dioxide laser device, and particularly to cooling a beam guide inclined plane mirror of a high-output carbon dioxide laser having a laser output of several kilowatts or more.

[Prior art]

In conventional carbon dioxide laser equipment, the oscillation medium, 1/-
In addition to Zagas, the circulation blower motor, the electrodes that provide electrical power, and the optical system that outputs the laser beam are directly or indirectly cooled with water, regardless of the oscillation or output of the laser beam. It was cooled by supplying water. Therefore, due to a temperature difference with the outside air or high humidity, dew condensation may occur on the inclined plane mirror, resulting in the problem that laser light is scattered or absorbed. However, due to dew condensation, dust from the atmosphere adheres, and the oscillation of laser light causes problems such as burn-in of the mirror sushi surface, resulting in loss of light.

In order to prevent condensation, it is possible to moisten the installation location of the laser device and adjust the temperature and humidity, but it is not practical as it requires a huge amount of nitrogen conditioning equipment, and air conditioning only near the inclined plane mirror is also possible. Although it is expected to be effective, it is necessary to operate it all the time.

In addition, the cooling temperature of the inclined plane mirror should be made close to the ambient temperature,
There is an idea to use indirect cooling, but the cooling is not sufficient and it is not practical.

[Purpose of the invention]

An object of the present invention is to prevent dew condensation from forming on the surface of an inclined plane mirror due to cooling in humid conditions.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

The laser beam 2 sent out from the laser device 1 enters the processing head 3 located in front, but the laser beam 2 and the processing head 3 are connected to each other.
Between 0 and 0, there is an external blocking mirror 5 which has a structure and mechanism that allows it to move from point A-A to A, /A/. When this external blocking mirror is at point A/A/, the laser beam is guided to the power meter 4. When the laser beam is at point A-A, the laser beam is guided to the processing head. The movement mechanism of the external blocking mirror includes:
Detection device 14, . 15 is attached, and the external shielding mirror is A.
-A.

When in A/A/, 14.15 respectively do not output a signal. The electromagnetic valves 9 and 10 open and close according to the signal from this detection device, thereby controlling the water supply to the external blocking mirror and the inclined plane mirror 6 that changes the direction of the laser beam.
do. That is, when measuring power with a power meter, the external shielding mirror is at the A/A/ point, and the detection device 15
A signal is output from the solenoid valve 9 to open the solenoid valve 9, and cooling water flows through the external shielding mirror for cooling. If the laser beam still advances to the processing head and is bent by the inclined plane mirror and focused by the condensing lens 7 for processing, the external blocking mirror is at point A-A, and a signal is output from the detection device 14 to trigger the electromagnetic valve. 10 is in the open state, and cooling water flows through the inclined plane mirror to cool it. Conversely, since cooling water does not flow through mirrors through which the laser beam does not pass, it is possible to prevent dew condensation from occurring when the mirror surface becomes below the dew point. In addition,
In the figure, 11 is a -hn workbench, 12 is a workpiece, and 13 is a chiller.

〔Effect of the invention〕

According to the present invention, even if the cooling water of the cooling device, which is necessary for cooling the gas in the laser oscillation device itself, is used to cool the external beam shutter and processing head, no condensation will occur due to overcooling, so the device can be simplified. It's a simple matter of opening and closing the external beam shutter, i, jll fK: Since the cooling water is controlled by the detection device, the only external control is opening and closing the external beam shutter. Wow

[Brief explanation of the drawing]

The figure is a schematic side sectional view of the laser processing device of the present invention. 1... Laser oscillator, 6... Inclined plane mirror.

Claims (1)

[Claims] 1. A device for circulating gas, a heat exchanger for cooling the gas, an optical system for laser generation, a cooling device for cooling this optical system, and a laser beam output from a laser oscillator.
A system consisting of a blocking and monitoring device, an inclined plane mirror that changes the direction of the laser beam at the center of the processing table, and a condensing lens that focuses the laser beam bent by the inclined plane mirror and hits the workpiece. , cooling the inclined plane mirror;
A laser processing apparatus characterized in that cooling other than that is separated, and automatically performs cooling water supply to the tilted plane mirror and stopping of water supply in conjunction with laser beam transmission from the laser oscillator.