JP2010123665A - Gas laser oscillator, and laser processing machine including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a gas laser oscillator capable of efficiently removing particles from a laser gas only by making the laser gas pass through a capture passage; and a laser processing machine including the same. <P>SOLUTION: This laser oscillator 1 includes a passage changeover means 27 in an intermediate part of a gas passage 12 of the laser gas. The laser gas is circulated in the gas passage 12 to pass through a filter 32 by a passage changeover plate 35 of the passage changeover means 27 in a state where laser light L does not oscillate. Thereby, particles 30 in the laser gas are efficiently captured by the filter 32. When the laser light L does not oscillate, the laser gas is circulated in the gas passage 12 so as not to pass through the filter 32 by a passage changeover plate 35 as shown in Fig.3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas laser oscillator and a laser processing machine including the same, and more particularly to a gas laser oscillator configured to remove particles (dust) from a laser gas and a laser processing machine including the gas laser oscillator.

Conventionally, a discharge excitation type gas laser oscillator provided with a main electrode in a gas container filled with a laser gas and a fan or a blower for circulating the laser gas in the gas container while flowing the laser gas in a discharge space between the main electrodes, Known (for example, Patent Document 1 and Patent Document 2).
In such a conventional gas laser oscillator, it is known that oxide powder of electrode material called particles is generated by discharge and floats in the laser gas. When the particles adhere to the pair of mirrors constituting the resonator, the transparency of the particles decreases, the laser light is absorbed by the particles, the output decreases, and both mirrors are heated and damaged. Also, if particles adhere to the electrode and become a protrusion, the discharge current concentrates on the electrode and damages the electrode, or if there are many particles floating in the laser gas, current flows through the particles and flows outside the electrode. The problem is that the discharge energy is deprived and the output of the laser beam decreases.
Therefore, conventionally, maintenance is regularly performed to remove particles adhering to the gas passage of the gas laser oscillator. Considering the current situation, if the particles generated and floating in the gas laser oscillator can be removed, the life of the laser gas can be extended, the maintenance interval can be lengthened, and the running cost can be reduced. Is possible.
JP-A-3-255680 Japanese Patent No. 2936264

By the way, conventionally, in the above-described gas laser oscillator, proposals for removing particles from the laser gas have been made. More specifically, in the laser oscillator disclosed in Patent Document 1, the middle of the laser gas circulation channel is divided into two inner and outer channels by a partition member, and a dust filter for capturing particles in the outer channel is provided. ing. However, in the apparatus of Patent Document 1, resistance to the flow of the laser gas is applied by the dust filter, so that the circulation flow of the laser gas is deteriorated, and many laser gases pass through the inner flow path where the dust filter is not provided. Will flow. For this reason, the apparatus disclosed in Patent Document 1 has a drawback in that the particle capture rate by the dust filter is poor.
On the other hand, in the apparatus of Patent Document 2, a part of the laser gas is sucked through a small-diameter external pipe connected to the laser chamber, and particles are removed by a filter arranged in the middle of the external pipe. I try to return it. However, the apparatus disclosed in Patent Document 2 has a drawback in that the particle capture rate is poor because only a part of the laser gas can be taken into the external pipe. In the apparatus of Patent Document 2, a pump for taking a part of the laser gas into the external pipe has to be provided separately from the laser gas circulation blower in the laser chamber.

In view of the circumstances described above, the present invention described in claim 1 is a gas laser oscillator including a gas passage through which laser gas circulates through a discharge space formed between discharge electrodes.
In the middle of the gas passage, a capturing passage having a capturing means for capturing particles in the laser gas and a non-capturing passage not having the capturing means are provided, and a flow path is provided so that the laser gas circulates through one of the passages. A flow path switching means for switching between the two is provided.
According to a second aspect of the present invention, on the premise of the configuration of the first aspect, the flow path switching means allows the laser gas to pass through the capture passage when the laser oscillation is stopped. .
Furthermore, the present invention described in claim 3 is a laser processing machine comprising the gas laser oscillator according to claim 1 or claim 2 and a control device that controls the operation of the gas laser oscillator and the laser processing machine.
The control device performs switching control of the flow path switching unit based on a signal input from a laser processing machine.

  According to the above-described configuration, the trapping passage having the trapping means and the non-capturing passage without the trapping means are provided in the middle of the gas passage through which the laser gas circulates. Particles can be removed. Further, when the laser beam is oscillated, the laser beam can be oscillated without lowering the output by oscillating the laser beam while the laser gas is circulating through the non-capturing passage.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a laser processing machine. The laser processing machine 1 can cut a plate-like workpiece 2 into a required shape. ing.
The laser processing machine 1 includes a processing table 3 that supports a workpiece 2 and is movable in the X-axis direction on a horizontal plane, a portal frame 4 that is disposed across the processing table 3, and a portal frame 4. A machining head 5 that is attached and movable in the Y-axis direction orthogonal to the X-axis direction, and a gas laser oscillator 6 that oscillates the laser light L and is disposed adjacent to the portal frame 4 are provided. The machining table 3 is moved in the X-axis direction by a first drive mechanism (not shown), and the machining head 5 is moved in the Y-axis direction by a second drive mechanism (not shown) disposed on the portal frame 4. It can be done.
Further, the laser processing machine 1 includes a control device 7, which can control the operations of the first drive mechanism, the second drive mechanism, and the gas laser oscillator 6. The control device 7 includes an operation panel 7A operated by an operator, and the operator can input necessary items to the control device 7 by operating the operation panel 7A. In the control device 7, a machining program corresponding to machining data such as a material, a machining shape, and a dimension of the workpiece 2 to be machined is set and stored in advance.

  Then, when the operator sets the gas laser oscillator 6 in a state where the laser beam L can be oscillated and places and holds the plate-like workpiece 2 on the processing table 3, the operator operates the operation panel 7A to operate the target. Items necessary for machining the workpiece 2 are input to the control device 7 to start machining. The control device 7 controls the operation of the gas laser oscillator 6 and the two drive mechanisms based on a preset machining program. That is, the control device 7 first operates both drive mechanisms to move the machining head 5 relative to the machining start point of the workpiece 2, and then oscillates the laser beam from the gas laser oscillator 6 to irradiate the workpiece 2. At the same time, the machining head 5 and the machining table 3 are moved relative to each other via both drive mechanisms to cut the workpiece 2 into a required shape.

In this embodiment, the axial flow type gas laser oscillator 6 is configured as follows so that particles in the laser gas can be efficiently removed. That is, as shown in the schematic configuration diagram of FIG. 2, the gas laser oscillator 6 includes two cylindrical plasma tubes 11 having the same structure, and a gas passage 12 through which the laser gas circulates through each plasma tube 11. It has.
The two plasma tubes 11 are arranged in a line in the axial direction, and opposite ends of the two plasma tubes 11 are supported by a central manifold 13 as a common support member. The other end of the plasma tube 11 on the front side (left side in the drawing) is supported by a front manifold 14 as a support member, while the other end of the plasma tube 11 on the rear side (right side in the drawing) is a rear manifold 15. Is supported by.
A front mirror 16 as an output mirror is attached to the front end face of the front manifold 14, and a rear mirror 17 is attached to the rear end face of the rear manifold 15. The front mirror 16 and the rear mirror 17 are disposed so as to face each other, and the laser light L oscillated in the plasma tube 11 is resonated between the front mirror 16 and the rear mirror 17 and then a part of the front mirror 16. So that the light is transmitted to the outside.

In each of the plasma tubes 11, two pairs of discharge electrodes 21 and 22 are arranged in series at positions facing each other in the axial direction, and a discharge space is formed between the pair of discharge electrodes 21 and 22. Yes. One of each pair of discharge electrodes is disposed as a ground side discharge electrode 21 on both ends of each plasma tube 11, that is, on each manifold 13 to 15 side, and the other non-ground side discharge electrode 22. Is arranged at the center of each plasma tube 11 in the axial direction. In the present embodiment, the discharge electrode 21 on the ground side is used as an anode, and the discharge electrode 22 on the non-ground side is used as a cathode. The ground-side discharge electrode 21 may be a cathode, and the non-ground-side discharge electrode 22 may be an anode.
Each of the pair of discharge electrodes 21 and 22 is connected to a DC high voltage circuit as a power source via a wiring (not shown), and a laser gas is circulated between the discharge electrodes 21 and 22 in each plasma tube 11. By applying a main voltage between each pair of discharge electrodes 21 and 22, main discharge is performed between each pair of discharge electrodes 21 and 22 to excite laser gas and oscillate laser light L. . Then, the laser light L oscillated between the discharge electrodes 21 and 22 is transmitted through the front mirror 16 and emitted to the outside of the plasma tube 11 as described above, and then the machining head via the light guide unit 8. After being guided to 5, the workpiece 2 is irradiated.
A low pre-ionization voltage is applied between the pair of discharge electrodes 21 and 22 when the laser beam L is not oscillated.

  The gas laser oscillator 6 includes pipes 23 to 25 having one ends connected to the manifolds 13 to 15, a blower 26 serving as a blowing means connected to the other end of the central pipe 24, and a pipe 23 at the end. , 25 connected to the other ends of the flow path switching means 27, 27, the communication pipes 28, 28 communicating between the blower 26 and the flow path switching means 27, 27, and the middle of the pipes 23-25. And each heat exchanger 29 for cooling the laser gas.

When the blower 26 is operated by the control device 7, the laser gas is sent out in the two directions of both connecting pipes 28, 28. By this blower 26, the laser gas is connected to the front side (left side) connecting pipe 28, the front side flow path switching means 27, the pipe 23, the heat exchanger 29 disposed on the pipe 23, and the front manifold 14. A laser gas is supplied to the plasma tube 11 on the front side via the. Further, the laser gas passes through the rear side connecting pipe 28 from the blower 26, the rear side (right side) flow path switching means 27, the pipe 25, the heat exchanger 29 provided on the rear side, and the rear manifold 15. It is supplied to the plasma tube 11.
Then, the laser gas supplied to each plasma tube 11 and circulated along the inside in the axial direction flows into the blower 26 from the central manifold 13 through the heat exchanger 29 through the pipe 24 and again into each communication pipe. 28 and 28.
That is, the gas passage 12 is formed by the internal spaces of the plasma tubes 11, the manifolds 13 to 15, the pipes 23 to 25, the connection pipes 28, the heat exchangers 29, the flow path switching means 27, and the blower 26. It is configured.

Next, since the front-side and rear-side flow path switching means 27 and 27 have the same configuration and their arrangement directions are reversed, only the configuration of the front-side flow path switching means 27 will be described. That is, as shown in FIGS. 3 to 5, the flow path switching means 27 located on the front side includes a box-shaped housing 31 having a space inside, and particles 30 in the laser gas provided in the housing 31. A filter 32 to be captured, and a flow path switching plate 35 for switching so that the laser gas passing through the housing 31 passes through either the capture passage 33 having the filter 32 or the non-capture passage 34 having no filter 32. A rotary air cylinder 36 serving as a drive source for swinging the flow path switching plate 35. The operation of the rotary air cylinder 36 is controlled by the control device 7.
The flow path switching plate 35 closes the outlet of the filter 32 by the rotary air cylinder 36 and closes the non-capturing passage 34 at a position (see FIG. 3) where the non-capturing passage 34 communicating from the connecting pipe 28 to the pipe 23 is formed. The filter 32 is swung to a position (see FIG. 4) where a capture passage 33 for guiding the laser gas to the inlet of the filter 32 is formed.
The front-side flow path switching means 27 is configured as described above, and as described above, the rear-side flow path switching means 27 is similarly configured with an arrangement opposite to the front side.

The laser beam machine 1 is configured as described above, and the control device 7 controls the operation of the gas laser oscillator 6 as follows. When starting up the gas laser oscillator 6, the laser gas is positioned by the flow path switching plate 35 so as to pass through the capture passage 33.
For this reason, all the laser gas circulated in the gas passage 12 by the blower 26 passes through the filters 32 of both flow path switching means 27 and 27, and if particles 30 are present in the laser gas at that time. Captured by filter 32. Although the flow rate of the laser gas is reduced by the filter 32, at this time, no main voltage is applied to the discharge electrodes 21 and 22, and the laser beam L is not oscillated, so no problem occurs.

  Next, when the work piece 2 is placed on the processing table 3 and positioned by the operator, and the automatic mode button of the operation panel 7A is pressed to execute the processing by the processing program, the control device 7 The rotary air cylinders 36 of both the flow path switching means 27 and 27 are operated in synchronism so that each flow path switching plate 35 is swung so that the laser gas passes through the non-capturing passage 34. Therefore, the laser gas delivered by the blower 26 circulates in the gas passage 12 through the non-capturing passage 34 without passing through the filter 32. In this case, since the laser gas flows through the housing 31 without passing through the filter 32, the laser gas flow rate is faster than the case where the laser gas passes through the filter 32 as described above.

Thus, in a state where the laser gas is circulating through the gas passage 12 via the non-capturing passages 34 of both the passage switching means 27, 27, the control device 7 executes a preset machining program. Then, the control device 7 applies a main voltage to the discharge electrodes 21 and 22 from a power source (not shown) in response to a command for oscillating laser light while executing the machining program. The laser gas is excited by main discharge in the space and the laser beam L is oscillated, and the laser beam L is emitted from the front mirror 16 to the outside as described above.
Thereafter, the laser beam L is applied to the workpiece 2 through the light guide 8 and the processing head 5, and laser processing is started. Further, the processing head 5 and the workpiece 2 are placed in a horizontal plane via the both drive mechanisms. Therefore, the workpiece 2 is cut into a required shape. Further, the control device 7 stops the application of the main voltage to the discharge electrodes 21 and 22 according to a command for stopping the laser oscillation of the machining program, and stops the oscillation of the laser light L. In this way, when the machining program is executed to the end and the machining of the workpiece 2 on the machining table 3 is completed, the control device 7 sets both the flow path switching plates 35 in a state where the blower 26 is operated. The laser gas is swung so as to pass through the capture passage 33. Therefore, all the laser gas passes through the capture passages 33 and the filters 32 of both of the flow path switching means 27 and 27 and circulates in the gas passage 12. As a result, when there is a particle 30 in the laser gas, it is captured by the filter 32 of both flow path switching means 27 and 27.
As described above, while the machining program is automatically executed, the laser gas passes through the non-capturing passage 33 so that the velocity of the laser gas flowing through the discharge space does not decrease, and the trapping passage 32 is set for other setup times. To pass.

  Note that when the laser processing machine 1 is caused to oscillate in the manual mode, the operator presses the laser ON button on the operation panel 7A. Then, first, the flow path switching plates 35 of both flow path switching means 27 and 27 are swung. As a result, the laser gas flows through the non-capturing passages 34 of both the flow path switching means 27 and 27. Then, when the flow rate of the laser gas flowing through the discharge space reaches a predetermined flow rate after a few seconds, the main voltage is applied to the discharge electrodes 21 and 22 from the power source, the main discharge is performed, and the laser light L is oscillated.

As described above, the gas laser oscillator 6 of the laser beam machine 1 according to the present embodiment includes the flow path switching units 27 and 27, and when the workpiece 2 is cut, that is, when the laser beam L is oscillated. In this case, the laser gas circulates through the non-capturing passage 34 of both flow path switching means 27 and 27. On the other hand, when the workpiece 2 is not cut, that is, when the laser beam L is not oscillated, all the laser gas circulates through the capture passages 33 of the flow path switching means 27 and 27 and the filter 32 therefor.
Therefore, when the workpiece 2 is cut, the flow rate of the laser gas is not reduced by the filter 32, so that the output of the laser light L oscillated in the plasma tubes 11 and 11 is not reduced.
On the other hand, in a state where the cutting process is not performed, all the laser gas circulates through the filter 32 and circulates, so that the particles 30 existing in the laser gas can be efficiently captured by the filter 32. As described above, when the particles 30 are captured, the filter 32 becomes a resistance and the flow rate of the laser gas is slowed down. However, in this state, the laser light L is not oscillated, so the problem that the output of the laser light L decreases. Does not occur.

Next, FIG. 6 shows a second embodiment of the present invention. This second embodiment uses the gas laser oscillator 6 of the present invention in the laser processing machine 1 provided with the pallet changer 51. . The configuration of the gas laser oscillator 6 and the machining table 3 of the second embodiment and the first drive mechanism for moving the machining table 3 in the X-axis direction, and the configuration of the machining head 5 and the second drive mechanism for moving the machining head 5 in the Y-axis direction are as described above. This is the same as the first embodiment.
The pallet changer 51 includes a plurality of pallets P for placing and holding the workpiece 2, and the operation of the pallet changer 51 is controlled by the control device 7. The control device 7 controls the operation of the pallet changer 51, loads the pallet P holding the workpiece 2 into the processing table 3, and after unloading the pallet P from the processing table 3 after the cutting process is finished, The pallet P is carried into the processing table 3.
In the second embodiment, the operation of the flow path switching means 27, 27 of the gas laser oscillator 6 is controlled by the control device 7 in association with the operation of carrying the pallet P into and out of the processing table 3 by the pallet changer 51. It has become.

That is, the operator at the site operates the operation panel 7A of the control device 7 to activate the laser oscillator 6 so that the laser gas passes through the capture passages 33 of the flow path switching means 27 and 27 as shown in FIG. Keep it.
Thereafter, the operator sets a program for continuous machining using the operation panel 7A, and sets the laser beam machine 1 to the automatic operation mode.
Thereafter, the workpiece 2 is placed on the first pallet P on the pallet changer 51 side, and then the operator presses a set completion button for the workpiece 2 on the pallet P using the operation panel 7A.
At this time, if preparation for receiving the pallet P on the processing table 3 is completed, the pallet changer 51 carries the first pallet P onto the processing table 3 and positions it. Then, since the control device 7 can recognize that the pallet P has been carried onto the processing table 3 by a sensor (not shown), the control device 7 does not capture the laser gas in the flow path switching means 27, 2 as shown in FIG. The flow path switching plate 35 is swung so as to pass through the passage 34.
Thereafter, the control device 7 performs a necessary cutting process on the workpiece 2 in the same manner as in the first embodiment described above in accordance with a preset automatic mode machining program.

During this time, the workpiece 2 is placed on the second pallet P on the pallet changer 51 side by the operator, and the operator presses the set completion button of the workpiece 2.
When the cutting process on the first pallet P on the processing table 3 is completed, the control device 7 switches the flow path switching means 27 and 27 of the gas laser oscillator 6 so that the laser gas passes through the capture passage 33.
After that, after the first pallet P is carried out from the processing table 3 by the pallet changer 51 and then the second pallet P is carried into the processing table 3 and positioned, the control device 7 displays the flow path switching means 27, 27. The laser gas is switched so as to pass through the non-capturing passage 34 as shown in FIG. Thus, since the laser gas passes through the trapping passage 33 during the pallet exchange, the particles 30 generated during processing on the first pallet P and floating in the laser gas are removed by the filter 32. Thereafter, the control device 7 cuts the workpiece 2 on the second pallet P. In the second embodiment, the same operation and effect as the first embodiment can be obtained.
Of course, the present invention can be applied to a laser oscillator of a biaxial orthogonal type or a triaxial orthogonal type.

The perspective view which shows one Example of this invention. The schematic block diagram of the gas laser oscillator 6 shown in FIG. Sectional drawing of the principal part shown in FIG. Sectional drawing which shows the state from which the principal part of FIG. 2 differs. Sectional drawing which follows the VV line | wire of FIG. The whole block diagram which shows 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser processing machine 2 ... Workpiece 6 ... Gas laser oscillator 11 ... Plasma tube 12 ... Gas passage 23, 24, 25 ... Pipe 27 ... Flow path switching means 28 ... Connection pipe 30 ... Particle 32 ... Filter 33 ... Capture passage 34 …… Non-catch passage

Claims (3)

In a gas laser oscillator having a gas passage through which laser gas circulates through a discharge space formed between discharge electrodes,
In the middle of the gas passage, a capturing passage having a capturing means for capturing particles in the laser gas and a non-capturing passage not having the capturing means are provided, and a flow path is provided so that the laser gas circulates through one of the passages. A gas laser oscillator comprising a flow path switching means for switching between the two.   2. The gas laser oscillator according to claim 1, wherein the flow path switching means allows the laser gas to pass through the capture passage when the laser oscillation is stopped. A laser processing machine comprising the gas laser oscillator according to claim 1 or 2 and a control device that controls the operation of the gas laser oscillator and the laser processing machine.
The laser processing machine, wherein the control device switches and controls the flow path switching means based on a signal input from the laser processing machine.

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