1. Field of the Invention
The present invention relates to a laser processing device comprising a laser oscillator for outputting a laser beam by exciting a laser gas and a laser machine for conducting laser processing, such as laser cutting or laser welding, by irradiating a work to be processed with a laser beam output from the laser oscillator.
2. Description of the Related Art
A laser processing device in general use includes a laser oscillator and a laser machine. A laser beam is output from the laser oscillator, and is focused on a work to be processed, by a focusing lens of the laser machine. As a result, the work to be processed is processed by a laser. In the case where a work to be processed is processed by this ordinary laser processing device, the processing conditions are predetermined based on the material of the work to be processed, the shape into which to be processed and the required cutting quality.
In
At the time of laser processing, the processing conditions included in the work data table are accessed and the laser processing operation is executed based on these processing conditions. Especially, and in the case of Japanese Unexamined Patent Publication No. 5-23883 as shown in
In the conventional laser oscillator as disclosed in Japanese Unexamined Patent Publication No. 5-23883, the pressure of the laser gas, though adjusted at the time of activating or deactivating the laser oscillator in some cases, is normally fixed to a specified value and not changed during the laser processing operation. A change in the laser gas pressure in the laser oscillator leads to a change in the characteristic of the laser beam output, and therefore it is desirable to set the laser gas pressure at an optimum level in accordance with the work material, the shape into which to be processed, the required cutting quality, etc. In the conventional laser processing device as disclosed in Japanese Unexamined Patent Publication No. 5-23883, the laser gas pressure is not changed and, therefore, an improvement in the processing performance of the laser processing device is limited.
In the prior art, therefore, it is difficult to process a plurality of works different in material, the shape into which it is to be processed or the required cutting quality in the same laser processing device. In processing these works, a plurality of laser processing devices or a plurality of focusing lenses having different focal lengths are required to be prepared for different materials of the work, or a plurality of processing heads are required to be used in accordance with the work material.
The present invention has been achieved in view of this situation, and the object thereof is to provide a laser processing device in which the processing performance is further improved by outputting the laser beam suited to the work material, the shape into which it is to be processed and the required cutting quality.
In order to achieve the object described above, according to a first aspect of the invention, there is provided a laser processing device comprising a laser oscillator for outputting a laser beam by exciting a laser gas, a laser machine for irradiating a work with a laser beam output from the laser oscillator, and a control means for controlling the laser oscillator and the laser machine, wherein the control means includes a storage means for storing a processing program for the work, and the processing program includes a required laser gas pressure value of the laser oscillator for the laser processing operation, which value is determined in accordance with the processing specifics of the work, wherein the control means further includes a laser gas pressure command transmission means for transmitting a laser gas pressure command based on the required laser gas pressure value to the laser oscillator, and wherein the laser oscillator includes a laser gas pressure changing means for changing the laser gas pressure of the laser oscillator in accordance with a laser gas pressure command transmitted by the laser gas pressure command transmission means.
Specifically, in the first aspect of the invention, the required laser gas pressure value is stored as the work processing conditions in accordance with the work material, the shape into which it is to be processed and the required cutting quality. Therefore, the laser gas pressure of the laser oscillator can be changed based on the required laser gas pressure value at the time of laser processing. Thus, a laser beam suitable for the work material, the shape into which it is to be processed and the required cutting quality can be output for an improved processing performance of the laser processing device.
According to a second aspect of the invention, there is provided a laser processing device as set forth in the first aspect, wherein the control means further includes a required laser gas pressure value adjusting means for adjusting the required laser gas pressure value.
Specifically, in the second aspect, the operator of the laser processing device can easily and simply adjust the required laser gas pressure value during the laser processing operation. Also, as the processing program is not required to be replaced, the processing operation can be switched from any one of a plurality of given works quickly to a different work, if required, during the laser processing operation.
According to a third aspect of the invention, there is provided a laser processing device as set forth in the second aspect, wherein the required laser gas pressure value adjusting means is a numerical value input means.
Specifically, in the third aspect, the operator can input a specific required laser gas pressure value.
According to a fourth aspect of the invention, there is provided a laser processing device as set forth in the second aspect, wherein the required laser gas pressure value adjusting means is a switching means for switching between a high pressure mode and a low pressure mode, and the required laser gas pressure value is adjusted in accordance with the high pressure mode or the low pressure mode switched by the switching means.
Specifically, in the fourth aspect, the required laser gas pressure value can be easily changed.
According to a fifth aspect of the invention, there is provided a laser processing device as set forth in the fourth aspect, wherein the high pressure mode and the low pressure mode are switched automatically by the switching means in accordance with the thickness of the work and/or the laser output of the laser oscillator included in the processing program.
Specifically, in the fifth aspect, a more suitable mode can be automatically selected in accordance with the contents of the processing program before performing the laser processing operation.
According to a sixth aspect of the invention, there is provided a laser processing device as set forth in the second aspect, wherein the required laser gas pressure value adjusting means automatically adjusts the required laser gas pressure value in accordance with the thickness of the work and/or the laser output of the laser oscillator included in the processing program.
Specifically, in the sixth aspect, the required laser gas pressure value can be automatically changed to an optimum value in accordance with the contents of the processing program before the laser processing operation.
According to a seventh aspect of the invention, there is provided a laser processing device comprising a laser oscillator for outputting a laser beam by exciting a laser gas, a laser machine for irradiating a work with the laser beam output from the laser oscillator, and a control means for controlling the laser oscillator and the laser machine, wherein the control means includes a storage means for storing a processing program for the work, wherein the processing program includes the thickness of the work and/or the laser output of the laser oscillator, wherein the storage means has stored therein the relation between the work thickness and/or the laser output and the required laser gas pressure value, wherein the control means includes a laser gas pressure command transmission means for transmitting to the laser oscillator a laser gas pressure command based on the required laser gas pressure value determined from the relation between the work thickness and/or the laser output and the required laser gas pressure value, and wherein the laser oscillator includes a laser gas pressure changing means for changing the laser gas pressure of the laser oscillator in accordance with the laser gas pressure command transmitted by the laser gas pressure command transmission means.
Specifically, in the seventh aspect, even in the case where a conventional data table of the processing conditions not containing the required laser gas pressure value is used, the optimum required laser gas pressure value can be set from the thickness of the work and/or the laser output. As a result, a laser beam suitable for the material of the work, the shape into which it is to be processed and the required cutting quality can be output for an improved processing performance of the laser processing device.
These and other objects, features and advantages of this invention will be made more apparent from the detailed description of typical embodiments taken in conjunction with the accompanying drawings.
a is a flowchart showing an operation of the required laser gas pressure value adjusting means.
b is a flowchart showing another operation of the required laser gas pressure value adjusting means.
Embodiments of the invention are described below with reference to the accompanying drawings. In the drawings, the same component members are designated by the same reference numerals, respectively. To facilitate understanding, the scales of the drawings are appropriately changed.
The laser oscillator 2 is a gas laser oscillator of discharge excitation type comparatively high in output, such as a carbon dioxide gas laser of 1 kW or more in output. The laser oscillator 2 includes a discharge tube 9 connected to a laser gas pressure changing means 18. The laser gas pressure changing means 18 can supply the laser gas to the discharge tube 9 through a laser gas supply port 17 and can discharge the laser gas from the discharge tube 9 through a laser gas discharge port 19 formed in the laser oscillator 2. A rear mirror 6 (internal resonator mirror) having a partial transmissivity is arranged at an end of the discharge tube 9, and an output mirror 8 having a partial transmissivity at the other end of the discharge tube 9. The output mirror 8 is formed of ZnSe. The inner surface of the output mirror 8 is coated for partial reflection and the outer surface of the output mirror 8 is coated for non-reflection. A laser power sensor 5 is arranged on the back of the rear mirror 6. As shown, two discharge sections 29a, 29b are formed in the optical resonator between the rear mirror 6 and the output mirror 8.
The discharge sections 29a, 29b each include a pair of discharge electrodes 7a, 7b arranged in positions to sandwich the discharge tube 9. The discharge electrodes 7a, 7b are assumed to have the same size and to be metalized or have a metal member mounted thereon. As shown in
Further, as shown, a turbo blower 14 is arranged on the discharge tube 9, and heat exchangers 12, 12′ are arranged upstream and downstream, respectively, of the turbo blower. Furthermore, the laser oscillator 2 is connected to a cooling water circulation system 22 to appropriately cool the laser gas, etc. in the discharge tube 9.
The laser beam output from the output mirror 8 of the laser oscillator 2 enters the laser machine 11. The laser machine 11 includes a plurality of, or in
By moving the processing table 23 in horizontal direction by a processing table moving means 21, the work 20 is set in position as desired. In similar fashion, the processing head 16 is moved in horizontal and vertical directions by a processing head moving means (not shown) and set in position as desired. Further, as shown in
In
The laser oscillator-related data 71 and the processing head-related data 81 are the optimum data determined experimentally in adaptation to the type of the work 20 to be processed, the shape into which to be processed and the required cutting quality. As shown in
For the operation of the laser processing device 100, the laser oscillator 2 is activated first. The laser gas is supplied into the discharge tube 9 through the laser gas supply port 17 by the laser gas pressure changing means 18 of the laser oscillator 2. Then, the laser gas is circulated in a circulation path including the discharge tube 9 by a turbo blower 14. As indicated by arrows in
In the discharge sections 29a, 29b, a predetermined voltage such as an AC voltage of several hundred kHz to several tens of MHz is applied by the discharge electrodes 7a, 7b. The laser gas is excited by the discharge operation thereby to generate a laser beam. In accordance with a well-known principle, the laser beam is amplified in the optical resonator, and can be output through the output mirror 8. The laser gas increased in temperature by the discharge operation is cooled by the heat exchanger 12 and returned to the turbo blower 14. In the process, the cooling water circulation system 22 is activated to cool the laser gas in the discharge tube 9.
With the activation of the laser oscillator 2, the program execution means 51 reads and executes the processing program 60 in the storage means 5. As a result, various signals corresponding to the laser oscillator-related data 71 and the processing head-related data 81 are transmitted to the laser oscillator 2 and the laser machine 11 which, in turn, are driven in accordance with the laser oscillator-related data 71 and the processing head-related data 81, respectively.
Specifically, a laser beam corresponding to the laser oscillator-related data 71 is generated from the laser oscillator 2. The laser beam supplied to the laser machine 11 is appropriately reflected by three reflectors 10a, 10b, 10c, converged by a focusing lens 13, and radiated on the work 20 through the processing head 16. As a result, the work 20 to be processed can be cut, welded or otherwise machined based on the processing condition data table.
As can be understood from
The laser gas pressure changing means 18, in response to the laser gas pressure command, either supplies the laser gas from the laser gas supply port 17 to the discharge tube 9 or discharges the laser gas through the laser gas discharge port 19. As a result, the pressure of the laser gas is increased or decreased to a value corresponding to the required laser gas pressure value 72. Once the pressure of the laser gas reaches a value corresponding to the required laser gas pressure value 72, a laser beam is output and the work 20 to be processed is actually processed. Incidentally, when changing the laser gas pressure, the laser power supply is controlled at the same time to maintain the discharge operation.
As described above, the laser oscillator-related data 71 including the required laser gas pressure value 72 and the processing head-related data 81 are the optimum data predetermined for the corresponding types etc. of the work 20 to be processed. In the prior art, the required laser gas pressure value 72 is not stored and the laser gas pressure is not controlled at the time of laser processing operation. According to this invention, in contrast, the laser gas pressure is controlled based on the required laser gas pressure value 72, and therefore, as compared with the prior art, a laser beam meeting the requirements of the material of the work to be processed, the shape into which it is to be processed and the required cutting quality can be output thereby to improve the processing performance of the laser processing apparatus 100.
Also, in the prior art, a plurality of laser processing devices are required to be prepared or the existing processing head is required to be replaced with another processing head for processing different types of the work to be processed. According to this invention, in contrast, the processing performance of the laser processing device 100 is so improved that the requirement to process a greater variety of the works 20 than in the prior art can be met, thereby reducing the need of preparing a plurality of laser processing devices or the need of replacing the processing head.
As shown in
The required laser gas pressure value adjusting means 55 can be used advantageously especially in the case where, during the laser processing operation of one of a plurality of works of a given type, for example, the need arises to process a different type of the work. In such a case, the given type of work being processed can be replaced with the different type of work quickly without replacing the processing program. Also, in the case where the numerical value input means 56 is used as the required laser gas pressure adjusting means 55, a specific numerical value of the required laser gas pressure value 72 can be input.
Also, as shown in
According to this invention, in the case where the thickness L of the work 20 to be processed is comparatively large, the required laser gas pressure value 72 and the laser output A included in the laser oscillator-related data 71 are set to be comparatively large. Similarly, in the case where the thickness L of the work 20 to be processed is comparatively small, the required laser gas pressure value 72 and the laser output A included in the laser oscillator-related data 71 are set to be comparatively small. In the second embodiment of the invention, therefore, the required laser gas pressure value adjusting means 55 of the control means 1 automatically performs the process of switching between the high gas pressure mode 58 and the low gas pressure mode 59 through the mode switching means 57, as described later.
As shown in
The required laser gas pressure adjusting means 55 determines the laser gas pressure from the map of
Even in the case where the mode switching means 57 according to the first embodiment shown in
As shown in these drawings, the thickness L of the work to be processed or the laser output A, after being read from the processing program 60 (steps 101, 201), is compared with the reference value L0 or A0, respectively (steps 102, 202). In the case where the thickness L of the work to be processed or the laser output A is larger than the predetermined values L0 or A0, as the case may be, the high gas pressure mode 58 is selected to increase the laser gas pressure. In the case where the thickness L of the work to be processed or the laser output A is not larger than the predetermined value L0 or A0, on the other hand, the low gas pressure mode 59 is selected thereby to decrease the laser gas pressure. Also in such cases, the optimum mode can be automatically selected in accordance with the contents of the processing program before the laser processing operation.
In
This invention is explained above with reference to typical embodiments, and it will be understood, by those skilled in the art, that this invention can be altered as described above and variously modified or added to without departing from the scope thereof.
Number | Date | Country | Kind |
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2005-214668 | Jul 2005 | JP | national |