JPH0124598B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a laser processing method.

[Conventional technology]

Laser processing, in which a laser beam emitted from a laser oscillator is focused by a focusing lens and the workpiece is irradiated with the laser beam to perform cutting, grooves, recesses, surface scraping, welding, etc., is well known and currently available. It is used in various fields.

However, with conventional laser processing, for example, when processing such as cutting or welding is performed on the workpiece,
There have been cases where the machined part of the workpiece is not finished smoothly, and depending on the purpose of the process, the machined part has to be finished by polishing.

Laser machining can easily and quickly cut, weld, or precisely process the workpiece, but as mentioned above, after the machining is finished, polishing etc. are performed to adjust the roughness of the machined surface. However, there is a problem in that it is difficult to achieve such a finish in microfabrication, which is usually the target of laser processing.

[Problems to be solved by the present invention]

The present invention has been made based on the above-mentioned viewpoints, and its object is to process the workpiece when the workpiece is cut or welded by irradiating the workpiece with a laser beam. The object of the present invention is to provide a laser machining method that provides a smooth finished part and eliminates the need to perform polishing or the like on the machined part upon completion of machining.

[Means to solve the problem]

The above object is achieved by machining the workpiece while applying a magnetic field to the laser beam irradiated portion of the workpiece.

[Effect]

As mentioned above, by performing laser processing within a magnetic field of a certain strength, the machined surface of the workpiece can be finished smoothly, and when the process is finished, the laser processing part of the workpiece can be finished smoothly. Since there is no need to perform polishing or the like, the scope of application of processing is expanded and processing time can be shortened.

Hereinafter, a detailed explanation will be given with reference to the drawings and an apparatus for carrying out the method of the present invention.

FIG. 1 is an explanatory diagram showing an embodiment of the apparatus for carrying out the method of the present invention, and FIG.
A sectional view and FIG. 3 are explanatory diagrams showing another embodiment.

First, FIGS. 1 and 2 will be explained.

In FIG. 1, 1 is a laser oscillator, 2 is a housing, 2a is a hole formed in the housing 2, and 3
a, 3b, 3c, and 3d are focusing lenses having mutually different focal points, and 4 is the above-mentioned focusing lens 3a, 3b, 3
5 is a motor attached to the outer peripheral wall of the housing 2; 6 is a partition plate; 7 and 8 are gas supply pipes for removing processing gas, processing waste, steam, etc.; 9; and 10 is a processing gas supply device 11 which supplies processing gas such as halogen gas, processing steam, gas, air for removing processing waste, inert gas, etc. through the processing gas supply pipes 7 and 8; is an electromagnet attached to the tip of the housing 2 facing the workpiece 12; 13 and 14 are cross slide tables;
15 is the cross slide table 13 and 14 mentioned above.
16 and 17 are motors for moving the cross slide tables 13 and 14 in the X-axis direction and Y-axis direction, 18 is an electromagnet provided as necessary, and the electromagnet is moved through the workpiece 12. 11, and in this case, together with the electromagnet 11, a magnetic field is applied to the processed portion of the workpiece 12. 19 is an electromagnet fixing member that fixes the electromagnet 11; 20 is a motor 5 that drives the laser oscillator 1 and the focusing lens fixing member according to a predetermined program; gas supply devices 9 and 10; and cross slide tables 13 and 14. The control device includes a numerical control device that collectively controls the motors 16 and 17 to be driven, a power supply device (not shown) that supplies voltage to the electromagnets 11 and 18, and the like.

The laser oscillator 1 is housed in a housing 2 so as to face the workpiece 12 in the laser beam oscillation output direction, and the laser oscillator 1
The output light from the laser oscillator 1 is directly focused by the focusing lens 3a, 3b, 3c, or 3d without having its optical path changed by a reflecting mirror or the like, and the laser beam oscillated from the laser oscillator 1 is directly focused by the focusing lens 3a, 3b, 3c, or 3d, and the processing part of the workpiece 12 is directly focused by the focusing lens 3a, 3b, 3c, or 3d. It is configured to be irradiated with.

The above laser oscillator 1 uses a CO ₂ laser or a He-Ne laser.
It is configured to use a gas laser such as a laser, a solid laser such as a ruby laser or a YAG laser, or the like, and to further increase the output by a Q-switching method or the like if necessary. The output and focus of the laser oscillator 1 are appropriately controlled by a control device 20, and the laser light output of the laser oscillator 1 can be continuous, strong or weak, or pulsed.

The four focusing lenses 3a, 3b, 3c and 3d each have a different focusing rate and are attached to a disc-shaped focusing lens fixing member 4, and the shaft of a motor 5 is fixed to the center of the focusing lens fixing member 4. ing.

By driving the motor 5 and rotating the focusing lens fixing member 4 according to the material, processing shape, processing state, etc. of the workpiece 12, the focusing lenses 3a, 3b, 3c, and 3d can be rotated. A focusing lens having a desired focusing rate is selected from among the above, and the laser beam emitted from the laser oscillator 1 is focused by the focusing lens into a beam spot of a desired size to perform processing. That is,
When performing precision cutting, etc., it is necessary to sufficiently focus the laser light emitted from the laser oscillator 1, so a focusing lens with a high focusing rate is selected. This is done by selecting a focusing lens with a low

Further, depending on the processing, a large number of lenses of the same type may be prepared and used in rotation to prevent the lenses from becoming hot due to absorption of laser light.

An electromagnet 11 is attached to the tip of the housing 2 so as to face the workpiece 12 , and an electromagnet 18 is attached to an electromagnet fixing member at a position facing the electromagnet 11 across the workpiece 12 . Endorsed by 19.

The center portions of the cross slide tables 13 and 14 to which the workpiece 12 is attached and the base 15 to which the cross slide tables 13 and 14 are attached are hollowed out and formed into a frame shape. The magnetic field is no longer prevented from acting on the processed portion of the workpiece 12, for example, as a magnetic flux in a direction penetrating the plate surface of the workpiece 12, and in a state where the magnetic flux is focused to a predetermined magnetic flux density. There is.

The laser beam oscillated from the laser oscillator 1 facing the workpiece 12 is applied to the part of the workpiece 12 to be processed by the focusing lens 3a selected by the control device 20. The beam is irradiated to the optimum beam spot, and a gas supply pipe 7 is installed in the above part for processing and for removing processing waste, steam, etc.
Processing gas such as halogen gas and other gases are supplied from gas supply devices 9 and 10 via gas supply devices 9 and 8 to perform processing, and voltage is supplied to electromagnets 11 and 12 from a power supply device (not shown). A magnetic field is applied to the laser beam irradiated portion of the workpiece 12 in the thickness direction of the workpiece 12 to perform processing.

Note that conditions such as the strength of the magnetic field applied to the processed portion of the workpiece, the magnetic flux density, the on/off of magnetic flux application, and the period of the on/off are adjusted as appropriate as the processing progresses. In addition, the processing gas is not limited to halogen gas, and various fluorocarbon gases, water vapor, oxygen gas, etc., or a mixture of these gases, etc. can be used depending on the material and processing shape of the workpiece 12. be done.

The processing feed of the workpiece 12 is controlled by the control device 20.
The numerical control device inside sends signals to the motors 16 and 17 that move the cross slide tables 13 and 14, respectively, according to a predetermined program, and machining is performed while the machining feed rate is controlled. The body 12 is processed with extremely high precision in a short period of time.

As described above, by performing the processing while applying a magnetic field to the laser beam irradiated portion of the workpiece 12, the processed portion of the workpiece 12 is finished smoothly, and the processed portion is polished at the end of the processing. There's no need.

Next, FIG. 3 will be explained.

In FIG. 3, the same numbers as in FIGS. 1 and 2 indicate the same components, 21 is a laser oscillator, 22 is a housing, 23a, 23b, 23c, and 23d (However,
In the figure, 23b and 28d are omitted. ) is a focusing lens, 24 is the above-mentioned focusing lens 23a, 23
A focusing lens fixing member fixing b, 23c and 23d, 25 motor, 26 partition plate, 27 and 28
29 and 30 are gas supply pipes for processing and removing processing waste, steam, etc.; 29 and 30 are gas supply devices for supplying processing gas such as halogen gas; and 31 is a device provided as necessary, similar to the electromagnet 18. in,
An electromagnet 32 is provided at the tip of the housing 21 opposite to the electromagnet 11 via the workpiece 12, and applies a magnetic field to the laser beam irradiated portion of the workpiece 12 together with the electromagnet 11. Laser oscillators 1 and 2 according to the program
1. Motors 5 and 25 that drive the focusing lens fixing members 4 and 24, gas supply devices 9, 10, 29 and 30, motors 16 and 17 that drive the cross slide tables 13 and 14, electromagnets 11 and 31
This is a control device that includes a numerical control device that collectively controls a power supply device (not shown) that supplies voltage to the power source and the like.

Therefore, in this embodiment, the laser oscillators 1 and 21 are provided facing each other, and the workpiece 12 is placed between them.
is attached to irradiate the workpiece with laser light from both sides of the workpiece, and the workpiece is processed while applying a magnetic field to the portion of the workpiece 12 that is irradiated with the laser light.

When performing laser processing, the control device 32 sends signals to the motors 5 and 25 in accordance with a predetermined program depending on the material and processing shape of the workpiece 12, as in the apparatus shown in FIG. , the focusing lenses 3a, 3b, 3c, 3d are attached to the focusing lens fixing members 4 and 24 to rotate the focusing lens fixing members 4 and 24 to focus the laser beams from the laser oscillators 1 and 21. and 23
Machining is performed after a predetermined one determined by the program is selected from among a, 23b, 23c, and 23d.

Thus, the laser beams emitted from the laser oscillators 1 and 21 are directed to the selected focusing lenses 3a and 2.
3a, the beam is sufficiently focused and irradiated onto the portion of the workpiece 12 to be processed. And the control device 32
controls the oscillation frequency of the laser oscillators 1 and 21 and supplies voltage to the electromagnets 11 and 12 according to a predetermined program, and a power supply circuit (not shown) and gas supply devices 9, 10, 2
9 and 30, cross slide tables 13 and 1
A signal is sent to and controlled the motors 16 and 17 that respectively move the workpiece 12, and processing is performed while applying a magnetic field to the laser beam irradiated portion of the workpiece 12 in the thickness direction of the workpiece 12. As a result of this action, the workpiece 12 is machined with high accuracy and a smooth finished surface in a short time.

In particular, in this embodiment, the laser oscillators 1 and 2
1 are provided facing each other, so when the laser beam from one laser oscillator 1 is supplied to the part of the workpiece 12 to be machined, the other laser oscillator 21 emits light from the workpiece 12. Processing is performed by irradiating a position corresponding to the irradiation point irradiated by the laser oscillator 1 from the back surface or a position slightly preceding the irradiation point in the direction of processing progress, so that the workpiece 12 can be processed with greater accuracy in a short time. High quality processing can be performed.

〔Example〕

(1) A YGA laser with an output of 50W and its beam spot are placed on a 50μ thick stainless steel plate.
The cutting process was carried out in a 4K Gauss magnetic field while focusing on 8μφ.

The roughness of the cut surface during cutting is 32μRmax,
The roughness of the cut surface after cutting was 11μRmax.

On the other hand, when stainless steel similar to the above is cut without applying a magnetic field,
The roughness of the cut surface during cutting was 82 μRmax, and the roughness of the cut surface after cutting was 18 μRmax.

(2) Welding was performed on stainless steel with a thickness of 50μ using a CO ₂ laser output of 650W, focusing the beam spot to 35μΦ, and in a magnetic field of 8K Gauss.

The surface roughness after welding was 16μRmax.

On the other hand, when stainless steel similar to the above is welded without applying a magnetic field,
The surface roughness after welding was 35μRmax.

〔Effect of the invention〕

Since the present invention is configured as described above, according to the present invention, by performing laser processing within a magnetic field, the processed portion of the workpiece can be finished with a smooth finish due to the interaction between the magnetic field and the plasma generated during laser processing. Since there is no need to perform polishing or the like on the machined part of the workpiece after finishing the process, the scope of application of the process can be expanded, the process time can be shortened, and the process cost can be significantly reduced. can.

Note that the present invention is not limited to the embodiments described above. That is, for example, in this embodiment, the laser oscillator and electromagnet were fixed and the workpiece was moved in the X-axis and Y-axis directions using a cross slide table, but the workpiece was not fixed. The structure may be such that the laser oscillator and the electromagnet are moved separately. Further, the mounting position of the electromagnet is not limited to the embodiment, and may be any other position as long as a magnetic field can be applied to the laser beam irradiated portion of the workpiece. Furthermore, although the focusing lens fixing member is driven by a motor, other known driving devices can be used for this purpose, and the focusing lens fixing member can be driven by a motor. During a predetermined processing interruption period, a cooling device that cools the focusing lens with cooling gas or liquid may be installed, or one or both of the distances between the focusing lens and the laser oscillator or the workpiece may be reduced by laser light. In order to adjust the degree of convergence or the position of convergence, the configuration may be such that the convergence can be relatively changed and adjusted. In addition, the method of controlling the power supply device (not shown) that supplies AC, DC, or pulsed excitation current to the electromagnet, the method of supplying gas from a gas supply device for processing, etc. are free within the scope of the purpose of the present invention. The present invention encompasses all of the design changes.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the apparatus for carrying out the method of the present invention, and FIG.
A sectional view and FIG. 3 are explanatory diagrams showing another embodiment. 1, 21... Laser oscillator, 2, 22... Housing, 3a, 3b, 3c, 3d, 23a, 23
c... Focusing lens, 4, 24... Focusing lens fixing member, 5, 25, 16, 17... Motor, 6, 2
6... Partition plate, 7, 8, 27, 28... Gas supply pipe, 9, 10, 29, 30... Gas supply device, 1
1, 18, 31... Electromagnet, 12... Workpiece,
13, 14...Cross slide table, 15...
...Base, 19...Electromagnet fixing member, 20, 32...
…Control device.

[Claims]

1 20-47% by weight of Sn, 2-12% by weight of Bi,
A solder alloy with excellent fatigue resistance characterized by consisting of 0.03 to 0.5% by weight of Cu and the balance Pb.