JPH04197593A - Method for cooling optical parts at outer part of laser beam machine - Google Patents

Abstract

PURPOSE:To prevent dew condensation caused by excess cooling and realize stability of service life. of optical parts by opening/closing a valve in cooling water passage synchronized with open/close of a shutter in a laser beam oscillator. CONSTITUTION:The carbon dioxide gas laser beam oscillator 5 is operated, and at the time of opening the shutter in the oscillator, the laser beam irradiates and machines a material W to be machined through a reflecting mirror 7 and a condensed lens 9 and heats this at the same time. A solenoid valve 13 is opened together with the shutter in the oscillator 5 with command of an NC device 3 to flow cooling water in the cooling water passage through a heat exchanger 11. By using a timer 15 between the solenoid valve 13 and the NC device 3, the solenoid valve 13 is closed after passing the fixed time from closing of the shutter with off-delay-timer. Therefore, as the reflecting mirror, etc., is not cooled to lower than the necessary temp., the moisture in the outer air is not condensed on surfaces of these parts.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Field of Industrial Application) This invention relates to a method for cooling external optical components of a laser processing machine.

(Prior art) ゛Reflection mirrors and condensing lenses outside the oscillator of laser processing machines are made of materials that reflect or transmit laser light with high efficiency. Alternatively, it was necessary to perform forced cooling using cooling water.

However, when water is used for cooling, condensation may occur on the surfaces of reflective mirrors, condensing lenses, etc. depending on the outside temperature and humidity, and water droplets may adhere to the surfaces of reflective mirrors, condensing lenses, etc. . In the case of a carbon dioxide laser, these water droplets absorb light, so that the reflecting mirror, condensing lens, etc. are heated and may be damaged.

In addition, when cooling with outside air, not only is the cooling capacity insufficient, but when cooling a condensing lens, air is applied directly to the surface of the condensing lens, so dust 1.
Dust similarly absorbed the carbon dioxide laser beam, causing the condenser lens to heat up and sometimes break.

(Problems to be Solved by the Invention) In general, reflective mirrors, condensing lenses, and the like used for reflecting and transmitting laser light have low resistance to water, and their coatings tend to peel off. However, due to the recent demand for high output oscillators, water cooling has no choice but to be used. If the temperature of the cooling water is close to the temperature of the outside air, the possibility of condensation will be reduced, but in many places the oscillator side is also water-cooled, and an increase in the temperature of the cooling water will directly reduce the oscillation efficiency and, in other words, the laser output. becomes.

This invention was created with attention to these points, and it prevents contamination and condensation on the laser reflecting mirror and condensing lens, stabilizes the lifespan of these external optical components, and provides high output power. The object is to provide an effective method for cooling external optical components of a laser.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a laser that cools a reflecting mirror for changing the optical path of a laser beam, a condensing lens, etc. by circulating water or the like. A processing machine is provided with a valve for regulating water circulation in its cooling waterway, and the valve is opened and closed in synchronization with the opening and closing of a shutter of a laser oscillator.

(Function) With this configuration, when the laser processing machine is operated and the shutter of the oscillator is opened, the laser beam passes through the reflecting mirror, the condensing lens, etc., and irradiates the workpiece. in this case,
As mentioned above, the reflective mirror, condenser lens, etc. are heated by the laser beam, but at the same time, the valve installed in the cooling channel opens and is cooled by the cooling water, so the temperature rise of the reflective mirror, condenser lens, etc. is prevented. It will subside as it becomes. When the laser processing is completed, the valve is closed, so that the reflecting mirror, condensing lens, etc. are not unnecessarily cooled. Therefore, moisture in the outside air does not condense on the surfaces of these parts.

(Example) Next, an example of the present invention will be described based on the drawings. FIG. 1 is an explanatory diagram in which the method of the present invention is implemented in a carbon dioxide laser processing machine. As shown in the figure, the carbon dioxide laser processing machine 1 is controlled by an NC device 3, and the laser beam emitted from the carbon dioxide laser oscillator 5 is reflected by a reflection mirror 7.
The optical path is changed by 90 degrees, and the light is focused by the condensing lens 9, and the condensed fish is tied onto the workpiece W to be drilled and cut.

Performs laser processing such as welding.

On the other hand, the cooling water made low temperature by the heat exchanger 11 cools the laser gas etc. of the carbon dioxide laser oscillator 5, and also cools the reflection mirror 7° condensing lens 9 etc. through the electromagnetic valve 13, and returns to the heat exchanger 11. It is returned to the factory to be cooled and used for circulation. The electromagnetic valve 13 opens when the shutter of the carbon dioxide laser oscillator 5 opens according to a command from the NC device 3, and allows the cooling water to pass therethrough.When the shutter closes, the solenoid valve 13 stops the cooling water after a certain period of time. A timer 15 provided between the solenoid valve 13 and the NC device 3 is an off-delay timer that closes the solenoid valve 13 after a certain period of time from when the shutter is closed.

With this configuration, when laser processing starts, the reflecting mirror 7, condensing lens 9, etc. are cooled by cooling water, but when laser processing is finished, after a certain period of time,
When their temperature drops to a suitable temperature, the cooling water is turned off. Therefore, the reflecting mirror 7, condensing lens 9, etc. are not cooled down to a temperature lower than necessary, so that no dew condensation occurs.

As mentioned above, an object of the present invention is to cool an external optical component so that moisture in the outside air does not condense on its surface by cooling it too much. Therefore, as in the present invention, if the inflow and outflow of cooling water is regulated by a solenoid valve and the amount of cooling water is controlled by laser output, the effect will be further improved. Furthermore, the relatively high temperature cooling water that comes out after cooling the laser oscillator may be used as cooling water for external optical components. Further, the cooling water before entering the external optical component may be heated with a heater or the like so that the difference between the cooling water and the outside temperature is reduced.

[Effects of the Invention] As can be understood from the above description, the present invention has the structure set forth in the claims, so it prevents contamination and dew condensation of the laser reflecting mirror and condensing lens, and In addition to stabilizing the lifespan of external optical components of a high-output laser, it is possible to provide an effective cooling method for external optical components of a high-output laser.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the present invention implemented on a carbon dioxide laser processing machine. 1... Carbon dioxide laser processing machine 13... Solenoid valve 15... Timer agent Patent attorney Hidekazu Miyoshi\ Figure 1

Claims (1)

[Claims] Reflective mirrors and condensing lenses for changing the optical path of laser beams, etc.
A laser processing machine that is cooled by water circulation, etc., wherein a valve for regulating water circulation is provided in the cooling channel, and the valve is opened and closed in synchronization with the opening and closing of a shutter of a laser oscillator. How to cool external optics.