JPS59133983A - Laser working device - Google Patents

Abstract

PURPOSE:To avoid waste of gas and to reduce operation expenses of a working device by utilizing it effectively in a working device which uses jointly the laser oscillator and the plasma generating device by using a discharged gas of a laser oscillator as a part of a plasma gas of a plasma generating device. CONSTITUTION:A laser gas is fed by a feed pipe 6 from a feed device 5 into a laser tube 2 of a laser oscillator 1, and a laser light is generated by discharge by an electrode 3, its direction is changed to 90 deg. by a reflection mirror 10, it is condensed by a lens 11, passes through in an electrode 14 of a plasma generating device 13, it is focused to a working part of an object 12 to be worked, and working such as cutting, etc. is executed. In this case, a laser gas is collected by a pipe 6', and a part of said gas passes through a feed pipe 7 and is fed to a plasma torch nozzle 15 together with a plasma gas fed from a gas feed device 8. A part of the laser gas is used as the plasma gas, therefore, the quantity of use of gas is reduced as a whole.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser processing apparatus that uses a laser oscillator and a plasma generator in combination.

Gas lasers include He-N e laser, Ar laser,
There are CO2 lasers, etc., and the laser oscillator is CO2
Taking a laser as an example, a gas mixture of CO2, N0% He, N2, etc. is used as a laser gas, and this is sealed in a laser tube to generate a gas discharge and oscillate a laser beam.

At this time, if the temperature of the laser gas exceeds a certain temperature (200°C), it will not oscillate efficiently, so the laser gas is flowed into the laser tube at high speed and is circulated by a laser gas supply device to cool it down. drain,
New gas is constantly supplied.

In addition, plasma generators use a power supply to apply voltage between electrodes to generate arc discharge, supplying plasma gas to the surrounding area to generate plasma, and in general, plasma processing requires low operating costs. Gasification accounts for more than 80%.

When processing using a laser oscillator and a plasma generator together, in conventionally known equipment, the laser gas and plasma gas are supplied from separate systems, and the exhaust gas from the laser oscillator is disposed of outside. In addition, the consumption of plasma gas is large, and it is necessary to supply processing gas, shielding gas, etc., so gasification accounts for the majority of operating costs, making it uneconomical.

The present invention has been made based on the above-mentioned viewpoints, and its purpose is to provide a laser processing apparatus with high processing efficiency and low operating costs.

The gist of this is that by using the exhaust gas of the laser oscillator as part of the plasma gas of the plasma generator, waste of gas can be eliminated and the cooling device for the laser gas can be omitted or simplified. be.

The details of the configuration of the present invention will be explained below based on the drawings.

FIG. 1 is an explanatory diagram showing one embodiment of a laser processing apparatus according to the present invention, and FIG. 2 is an explanatory diagram showing another embodiment of the present invention.

In Figure 1, 1 is a laser oscillator, 2 is a laser tube, 3 is a discharge electrode, 4.41 is a reflecting mirror of laser oscillator 1, 5 is a laser gas supply device, 6.6' is a laser gas supply tube, and 7 is a laser oscillator. 1 is a gas supply pipe that draws the exhaust gas from 1 and sends it to the plasma generator; 8 is a gas supply device; 9 is a casing; 10 is a laser beam reflection plate; 11 is a focusing lens; 12
1 is an island to be processed, 13 is a plasma generator, 14 is one electrode for plasma generation, 15 is a plasma torch nozzle, 1
5a is a hole provided at the tip of the nozzle 15, 16 is an electric wire device for generating plasma, and 17 is a resistor.

In this embodiment, a single straight laser tube 2 of the laser oscillator 1 is used, but in order to increase the tube length and increase the output, an appropriate reflecting mirror is used to change the optical path of the laser beam. , a plurality of laser tubes may be provided. Also, laser tube 2
Details such as the external cooling water jacket are omitted.

The discharge electrode 3 discharges the laser gas within the laser tube 2 to excite the particles of the laser gas and generate laser light.

The reflecting mirror 4 totally reflects the laser light generated in the laser tube 2,
The reflecting mirror 41 is semi-transparent and transmits a portion of the laser beam.

The laser gas supply device 5 sends laser gas into the laser tube 2 from a laser gas supply tube 6, causes it to flow inside the laser tube 2 at high speed, recovers it from the laser gas supply tube 6', cools it, and circulates it.

At this time, the laser gas supply device 5 is configured to send, for example, two-fifths of the collected laser gas to the gas supply pipe 7 as exhaust gas, and circulate three-fifths of the collected laser gas. Further, the discharged insufficient amount is newly supplied by the laser gas supply device 5.

Since the amount of exhaust gas increases as the laser oscillator becomes larger, it is very advantageous to utilize this in large laser oscillators.

The composition of the laser gas is different from that of the plasma gas, and the amount of exhaust gas from the laser oscillator is small compared to the consumption of plasma gas (according to experiments, 1.2 kW
The exhaust gas of the laser oscillator 1 is approximately 1'00 #/'h
On the other hand, the plasma gas of a 1.5 kW plasma generator is approximately 800β/h. ) In order to use this as a plasma gas, the composition of the gas must be changed and at the same time, the insufficient gas must be supplied.

An example of the volume ratio composition of laser gas and plasma gas is shown below: Laser gas; Ar:He:CO2:N2 #O~0.5:9
．． :1. : 3 plasma gas; Ar :He :CO2:N2 L=, 0.5~1 :
The ratio is 3:1:3.

The gas supply device 8 supplies the insufficient gas at an appropriate rate,
The exhaust gas from the laser oscillator 1 is mixed with this and sent to the plasma generator as a composition and amount suitable for plasma gas.

The reflecting plate 10 is attached to the casing 9 and reflects the laser light emitted from the laser oscillator 1 to change the optical path.

The lens 11 is mounted in the casing 9 so as to be freely positionable by sliding control movement in the tube axis direction, and focuses the laser light reflected on the reflector plate 10 to a processing point on the workpiece 12 .

The power supply device 16 applies a voltage sufficient to start and generate a discharge between the electrode 14 (cathode) of the plasma generator 13, the electrode nozzle 15 (anode), and the workpiece 12 (anode). In this case, the nozzle 15 (anode) and the workpiece 12
(anode), a suitable potential difference is applied by a resistor 17.

The plasma generator 13 is provided coaxially with the optical axis of the laser beam, and generates plasma by supplying mixed plasma gas from the gas supply pipe 7 and applying voltage by the power supply device 16, and this plasma is generated by the laser beam. Irradiation is directed towards the irradiation point.

The workpiece 12 is attached to a workpiece of a cross table (not shown) connected to a numerical control device (not shown), and the workpiece is two-dimensionally moved according to commands from the numerical control device. do.

Laser gas particles in the laser tube 2 of the laser oscillator 1 are excited by the discharge from the discharge electrode 3 and generate one laser beam, which successively causes stimulated radiation and is emitted between the reflector 4 and the reflector 4/. The laser beam resonates to increase its intensity, transmits through the reflecting mirror 41, and is sent out as a beam of laser light.

At this time, the laser gas flowing through the laser tube 2 is recovered by the laser gas supply device 5, and a part of it is guided as exhaust gas to the gas supply tube 7, where it is mixed with an appropriate gas from the gas supply device 8 and is used to generate a plasma generator. 13 and used as plasma gas.

A laser beam emitted from a laser oscillator 1 is reflected by a reflection plate 10 to change its optical path, and then is focused by a lens 11 and collected at a processing point on a workpiece 12.

On the other hand, a voltage is applied to the plasma generator 3 by the power supply device 16 to cause arc discharge, and the mixed plasma gas is supplied to generate plasma.

Since this plasma is configured to gather at the laser beam irradiation point of the workpiece 12, a high energy density impact is applied to the laser beam irradiation point, and processing such as welding, cutting, fusing, etc. I can do it.

The workpiece 12 of the cross table (not shown) to which the workpiece 12 is attached is moved two-dimensionally by commands from a numerical control device (not shown), so the workpiece 12 can be positioned at a desired position and at the desired circumference. Processing is performed.

According to an experiment using an embodiment of the present invention, a 400 W plasma generator was used, and the laser oscillator was
When a gas of K and W was used, it could be used as a Narazuma gas by adding about 200j2/h of gas to the exhaust gas from the laser oscillator.

Furthermore, since laser oscillation is not hindered even if the laser gas is not specially cooled, costs for the apparatus and operation can be reduced.

FIG. 2 is an explanatory diagram showing an embodiment of the present invention in which a magnetic field coil is provided at the tip of a nozzle of a plasma generator.

In FIG. 2, 9.11 to 16 indicate the same components as shown in FIG. 1, and 8 is a magnetic field coil.

The magnetic field coils 18 are provided radially along the inner wall of the hole 15a at the tip of the nozzle 15, centered on the axis of the hole 15a', and have magnetic poles configured to surround the generated plasma. A voltage is applied by the device to generate a magnetic field directed toward the center of the hole 15a.

Further, the magnetic field coil 18 may be provided coaxially so as to be wound around the axis of the hole 15a to generate a magnetic field substantially coaxial with the laser beam and plasma.

The generated plasma is constricted by this magnetic field, its cross-sectional area becomes smaller, its electrical density increases, and it is ejected as high-temperature, high-pressure plasma.

Generally, a plasma generator has a central rod-shaped electrode (cathode).
A voltage is applied between the nozzle (anode) or the workpiece (anode) to generate an arc discharge, and plasma gas flows around the arc to flow out from the tip of the nozzle to cool the area around the arc. At the same time, the electrical resistance is increased to narrow the arc, increasing the electrical density in the arc and generating high-temperature, high-pressure plasma.

At this time, as the arc is narrowed to reduce its cross-sectional area, the electric density increases and high-temperature, high-pressure plasma can be generated, so in addition to cooling by gas flow, heat absorption by gas dissociation is utilized.

In this example, a magnetic field coil is provided at the tip of the nozzle of the plasma generator to generate a magnetic field, and this magnetic field narrows the plasma to increase the electric density and generate higher temperature and higher pressure plasma. be.

Although not shown, similarly to the previous embodiment, the laser gas flowing in the laser tube of the laser oscillator is collected by the laser gas supply device, and a portion of it is collected as exhaust gas by the gas supply tube 7.
The gas is mixed with an appropriate gas from the gas supply device, sent to the plasma generator 13, and used as a plasma gas.

Since the present invention is configured as described on paper, the exhaust gas of the laser oscillator is used as part of the plasma gas of the plasma generator, so the processing efficiency is high.
A laser processing device with low operating costs can be provided.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of a laser processing apparatus according to the present invention, and FIG. 2 is an explanatory diagram showing another embodiment of the present invention. 1−・−1−−−−−−−−−−Laser oscillator 5 −
----------- --- Laser gas supply device 7 ---
−−−−−−−−−−−Gas supply pipe 8−・−−−1−
------------・----1--Gas supply device 12-・
−−11−−−−−−−−−−−−−・Workpiece 1
3---1. <Tukusu Research Institute Agent (7524) Shotabe Mogami

Claims (2)

[Claims] (1) In a laser processing device that uses both a laser oscillator and a plasma generator for processing, connect the laser oscillator's lede gas exhaust pipe to the plasma generator gas supply pipe to remove the exhaust gas from the laser oscillator. The above laser processing device is characterized in that it is used as part of plasma gas. (2) The laser processing device according to claim 1, wherein a magnetic field coil is provided at the nozzle tip of the plasma generator.