JPH05192782A - Laser beam machine - Google Patents

Abstract

PURPOSE:To prevent a stain dewing and generation of heat lens effect of a optical part with dust, etc. CONSTITUTION:A manifold 103 is arranged at a clean air introducing part 100 of a mirror unit 12A, the clean air is once supplied to the manifold 103 through a regulator 45A and a connector 102, passed through the manifold 103 and the clean air is made to a uniform flow, jetted from an air blowing opening 106, blown in parallel to the surface of a mirror 11 and reaches a duct 122 of a clean air discharging part 120. Then, it is sucked by a fan 204 and discharged. And a sub-blowing opening 104 is arranged at the clean air introducing part 100, the clean air introduced through a connector 101 is allowed to flow from this sub-blowing opening 104 into a space 107 inside the mirror part 110 and made so as to cover over the circumference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus for guiding a laser beam by an optical component to irradiate a workpiece to perform laser processing, and more particularly to a laser processing apparatus for preventing contamination of an optical component.

[0002]

2. Description of the Related Art In recent years, the output of a laser processing apparatus has tended to increase, and it has become possible to process a material having a plate thickness which was previously impossible by laser processing.
In addition to the increase in laser output, the increase in processed plate thickness
This means that the processing speed decreases and the processing time increases. Further, if a thick plate is cut and welded, a large amount of dust is generated, which is incomparable to conventional thin plates. Therefore, optical components such as a reflector and a lens for guiding a laser beam have come to be used under more severe conditions and environments.

As described above, a laser processing apparatus equipped with a high-power laser has come to be used in a harsh environment, and accordingly, the optical components used in the laser processing apparatus have the following problems. There is.

Dust, oil and water adhere to the mirror surface,
When the mirror surface is irradiated with a laser beam, the high-power laser instantly generates heat and heats the mirror surface, so that the mirror coating and the mirror substrate locally undergo thermal expansion, and the reflected laser beam is deformed. have a finger in the pie. As a result, the quality of the laser beam is remarkably impaired, and the reduction of the laser output due to the damage of the mirror is accompanied by the deterioration of the processing performance.

Further, in a high power laser, even when the mirror surface is clean, the heat generated by the original beam absorption of the mirror is so large that it cannot be ignored. The same applies to the case of a transparent optical component such as a lens.
Therefore, the mirror is cooled by cooling water from the surroundings to prevent a rapid temperature rise of the mirror. However, when the laser beam is not irradiated, the temperature on the mirror surface is lowered and there is a risk of dew condensation. If condensation occurs, the mirror may corrode due to absorption of the laser beam, heat generation, or leaving the condensation for a long time.

Furthermore, when the laser beam is irradiated, the temperature of the surface of the optical component rises because it takes time to transfer heat from the mirror surface to the cooling water. In particular,
The temperature rises sharply in the center of the beam where the power density is high,
Since thermal expansion occurs, the optical component expands around the center of the beam, and a so-called thermal lens effect is generated, which behaves as if it were a lens. In this case, the deformation of the laser beam is unavoidable, and in this case as well, the processing performance deteriorates.

[0007]

Therefore, conventionally, such problems have been individually addressed. That is,
For adhesion of dust, water, and oil on the surface of optical components,
Machining performance is achieved by filling the light guide path (space for guiding the laser beam) of the laser processing device with clean air to prevent dust and other foreign matter from entering the light guide path itself, and often by removing and cleaning the optical components. I was trying to keep it.
However, it is not enough to fill the light guide path with clean air, and when the laser processing device goes into operation, the internal air also moves as it moves, and the dust and the like floating at that time move to the surface of the optical component. May adhere. In a high-power laser, if the surface of an optical component to which dust or the like adheres once is irradiated with a laser beam, the optical component will be fatally damaged. Further, dust and the like can be surely removed by removing the optical component and washing it, but this requires a lot of man-hours.

Regarding dew condensation, the temperature of the cooling water is raised or dry air is introduced, but
Condensation once attached cannot be resolved easily. In addition, the actual situation is that there is no effective means for the occurrence of the thermal lens effect.

The present invention has been made in view of the above circumstances, and provides a laser processing apparatus capable of preventing contamination of optical parts by dust or the like, preventing dew condensation, and preventing occurrence of a thermal lens effect. With the goal.

[0010]

According to the present invention, in order to solve the above problems, a laser processing apparatus for guiding a laser beam using an optical component to irradiate a workpiece to perform laser processing is provided. There is provided a laser processing apparatus having an optical component protection means for blowing clean air in the vicinity thereof.

[0011]

The optical component protection means blows clean air near the surface of the optical component. Therefore, the dust and the like adhering to the surface of the optical component is removed, and the contamination of the optical component by the dust and the like can be prevented. Further, it is possible to remove the dew condensation attached when the laser beam is not applied. Further, since the surface of the optical component is effectively cooled by the clean air, it is possible to prevent the thermal lens effect from occurring. Further, in the past, the temperature of the forced cooling water was set to be somewhat higher in order to prevent dew condensation caused by the temperature drop of the optical parts, but as described above, the dew condensation can be removed by the clean air, so the forced cooling The water temperature can be set lower. Also from this point, the cooling effect of the optical component is improved, and the thermal lens effect can be prevented from occurring.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 is a diagram showing an example of the laser processing apparatus of the present invention. In the figure, the laser processing apparatus is a three-dimensional laser processing apparatus, and includes a laser oscillator 1, a processing head 2, a processing table 3, an optical component protection system 4, and a numerical controller 5.
Composed of. The laser beam emitted from the laser oscillator 1 is guided to the processing head 2 via the light guide paths 11A, 11B, 11C, 11D and the mirror units 12A, 12B, 12C, 12D. The mirror unit 12D is installed in the processing head 2. Here, the light guide paths 11A to 11D are configured to be telescopically expandable. The mirror units 12A to 12D also include an optical component protection unit, which will be described later.

The laser beam is applied from the processing head 2 to the work on the processing table 3 to perform laser processing. The machining head 2 is configured to be movable in X, Y, and Z directions as shown in the drawing, and its movement is controlled by the numerical controller 5. The three-dimensional shape processing is performed on the workpiece according to the movement of the processing head 2 in the X, Y, and Z directions.
The light guide paths (telescopes) 11B and 11D expand and contract according to the movement of the processing head 2 in the X and Y directions.

The optical component protection system 4 is a system for sending clean air to the mirror units 12A to 12D, and comprises an air compressor 41, an air cleaning unit 42, and mirror units 12A to 12D. An air pipe 43 is connected between the air cleaning unit 42 and each of the mirror units 12A to 12D. The optical component protection system 4 is sequence-controlled by a numerical controller 5. Next, the optical component protection system 4 will be described with reference to FIG.

FIG. 3 is a block diagram of an optical component protection system. In the figure, an electromagnetic valve 44 is provided between the air compressor 41 and the air cleaning unit 42 of the optical component protection system 4. The air cleaning unit 42 further includes an air dryer 42A, an oil mist separator 42B, a filter 42C and a regulator 42D. When the laser processing device is started up, the air compressor 41 and the air dryer 42A immediately start operating in response to a command signal from the numerical control device 5. The numerical controller 5 keeps the electromagnetic valve 44 closed until the air dryer 42A is warmed up and the dehumidifier operates sufficiently to prevent the air pressurized by the air compressor 41A from entering the inside of the device while being moistened. .. When the air dryer 42A is sufficiently warmed up for a certain period of time, the electromagnetic valve 44 is opened. The air introduced into the air cleaning unit 42 by this sequence control is highly dried by the air dryer 42A, and dust and oil are completely removed by the oil mist separator 42B and the filter 42C to become clean air. After the pressure is adjusted, it is delivered to each mirror unit 12A to 12D. Regulators 45A to 45D are provided in front of the mirror units 12A to 12D, and the flow rate of clean air is adjusted by the regulators 45A to 45D.
It is evenly distributed and introduced into the mirror units 12A to 12D. Therefore, each mirror unit 12A-12D
The difference in the flow rate of the clean air due to the difference in the length of the air pipe 43 before reaching the
The clean air introduced into D is always kept at an appropriate flow rate.
Next, the mirror units 12A to 12D will be described.

FIG. 4 is a diagram showing a schematic structure of the mirror unit. Here, the mirror unit 12A will be described, but the other mirror units 12B to 12D are similarly configured. The mirror unit 12A includes the clean air introduction unit 1
00, a mirror unit 110, and a clean air discharge unit 120. The clean air introduction part 100 and the clean air discharge part 120 form an optical component protection unit. The clean air is introduced into the clean air introducing section 100 from the arrow 201 in the figure, passes through the mirror section 110, and is discharged from the clean air discharging section 120. Further, the laser beam from the laser oscillator enters the mirror unit 110 from the direction of arrow 203 in the figure, is reflected in the direction of arrow 204, and is emitted.

FIG. 1 is a detailed view of the mirror unit, which is taken along the line AA in FIG. A manifold 103 is provided in the clean air introduction part 100 of the mirror unit 12A, and the clean air is once supplied to the manifold 103 via the regulator 45A and the connector 102. The clean air that has passed through the manifold 103 and becomes a uniform flow is ejected from the air ejection port 106, is blown in parallel to the surface of the mirror 111, and reaches the duct 122 of the clean air discharge part 120. Then, it is sucked and discharged by the fan 123. A filter 121 is provided in the duct 122 to prevent dust from entering from the outside.

Further, the clean air introducing section 100 is provided with a sub jet port 104, and the clean air introduced through the connector 101 is supplied from the sub jet port 104 to the mirror section 110.
It flows into the internal space 107 and covers the entire area.

The mirror 111 is held by a mirror holder 115. A cooling unit 112 is provided on the rear surface side of the mirror 111, and the mirror 111 includes the cooling water passage 11 of the cooling unit 112.
It is forcibly cooled by the cooling water flowing through 3. The cooling water is introduced from the water supply port 114 and discharged from the discharge port 115.

As described above, since the clean air introducing section 100 and the clean air discharging section 120 are provided in the mirror unit 12A and the clean air is blown in parallel to the surface of the mirror 111, the dust adhered to the surface of the mirror 111. Etc. are removed, and the contamination of the mirror 111 due to dust or the like can be prevented.

As shown in FIG. 2, while the laser processing apparatus is operating, the light guide paths 11A to 11D constituted by the telescope repeat expansion and contraction as the processing head 2 moves, so that the air inside the light guide paths 11A to 11D is expanded. Always goes in and out through the gap. It also moves within the light guide paths 11A to 11D. Now, in this laser processing apparatus, if the processing head 2 simultaneously moves in the X, Y, and Z directions at a speed of 40 m / min, the inner diameter φ of the light guide paths 11A to 11D will be 100 m.
As m, air having a maximum flow rate of 942 L / min moves in the mirror units 12A to 12D. This corresponds to a wind of 2 m / sec, and the light guide path 11A to
Sufficient to wind up the dust in 11D, and such rapid expansion causes a pressure drop in the light guides 11A to 11D, and it is inevitable that outside air leaks into the light guides 11A to 11D. .. However, each mirror unit 12A
Since clean air is blown every ~ 12D, even if a large amount of air passes through the light guide paths 11A to 11D, the mirror 111 and the like are protected. Therefore, it is possible to minimize the contamination of the mirror 111 itself and the damage caused by the contamination. Such an effect is obtained by the auxiliary jet 1
Mirror unit 12A by blowing clean air from 04
By covering the inside of the space 107 of up to 12D with clean air as well, it is possible to obtain more reliably.

The mirror 11 is used when the laser processing apparatus is in a rest state, that is, when the laser beam is not applied.
1 Even if dew condensation occurs on the surface, the dew condensation can be removed. In that case, after the clean air is blown onto the surface of the mirror 111 for a predetermined time, the laser processing apparatus may be put into operation by sequence control. Water adhering to the surface of the mirror 111 is sufficiently removed within the predetermined time.

Furthermore, since the surface of the mirror 111 is effectively cooled by the clean air, it is possible to prevent the thermal lens effect from occurring. Conventionally, the temperature of the forced cooling water is set to a relatively high temperature in order to prevent the dew condensation caused by the temperature decrease of the mirror 111. However, since the dew condensation can be removed by the clean air as described above, the forced cooling water can be removed. The temperature can be set lower. From this point as well,
The cooling effect of the mirror 111 is improved, and the thermal lens effect can be prevented from occurring.

Further, as shown in FIG. 4, the direction in which the clean air flows is set to be perpendicular to the plane formed by the optical paths (arrows 203 and 204) of the laser beam reflected by the mirror section 110. Therefore, the clean air introduction part 100 and the clean air discharge part 120 are provided on both sides of the mirror part 110, respectively.
Moreover, it can be provided at a position where it does not interfere with the laser beam at all. Therefore, the clean air introduction part 100 and the clean air discharge part 120 can be made compact.

In the above description, the clean air is blown to the mirror, but it may be blown to other optical parts such as a condenser lens.

[0026]

As described above, in the present invention, the clean air is blown to the vicinity of the surface of the optical component, so that the dust and the like adhering to the surface of the optical component is removed and the optical component is contaminated by the dust and the like. Can be prevented. Also,
Condensation attached when the laser beam is not applied can be removed. Further, since the surface of the optical component is effectively cooled by the clean air, it is possible to prevent the thermal lens effect from occurring. Further, in the past, the temperature of the forced cooling water was set to be somewhat higher in order to prevent dew condensation caused by the temperature drop of the optical parts, but as described above, the dew condensation can be removed by the clean air, so the forced cooling The water temperature can be set lower. Also from this point, the cooling effect of the optical component is improved, and the thermal lens effect can be prevented from occurring.

As a result, the service life of the optical components can be greatly improved, and the intervals of regular maintenance and inspection can be extended. Therefore, reliability is also improved.

[Brief description of drawings]

FIG. 1 is a detailed view of a mirror unit, which is taken along the line AA in FIG.
It is a cross section.

FIG. 2 is a diagram showing an example of a laser processing apparatus of the present invention.

FIG. 3 is a block diagram of an optical component protection system.

FIG. 4 is a diagram showing a schematic configuration of a mirror unit.

[Explanation of symbols]

 1 Laser Oscillator 2 Processing Head 3 Processing Table 4 Optical Component Protection System 5 Numerical Control Unit (CNC) 12A to 12D Mirror Unit 41 Air Compressor 42 Air Cleaning Unit 42A Air Dryer 42B Oil Mist Separator 42C Filter 42D 45A to 45D Regulator 43 Air Piping 44 Electromagnetic valve 45A to 45D Regulator 100 Clean air inlet 103 Air jet 104 Sub jet 110 Mirror 120 Clean air exhaust

Claims (9)

[Claims] 1. A laser processing apparatus for guiding a laser beam using an optical component to irradiate a workpiece to perform laser processing, comprising an optical component protection means for blowing clean air near the surface of the optical component. Characteristic laser processing equipment. 2. The laser processing apparatus according to claim 1, wherein the optical component protection means is provided for each of the optical components. 3. The laser processing apparatus according to claim 1, wherein the clean air is generated via an air compression unit, a valve, and an air drying unit. 4. The laser processing apparatus according to claim 3, wherein the air compression unit, the valve, and the air drying unit are sequence-controlled. 5. The laser processing apparatus according to claim 1, wherein the clean air is generated via an air cleaning means. 6. The laser processing apparatus according to claim 1, wherein the clean air is blown from one side of the optical component in the vicinity of the surface of the optical component. 7. The laser processing apparatus according to claim 1, further comprising air discharging means, wherein the clean air blown from the optical component protecting means is discharged from the air discharging means. 8. The optical component protection means has an injection port for blowing the clean air in the vicinity of the surface of the optical component, and a sub injection port for covering the periphery of the optical component with the clean air. The laser processing apparatus according to claim 1, further comprising: 9. The laser processing apparatus according to claim 1, wherein the clean air is caused to flow in a direction perpendicular to a surface formed by an optical path of a laser beam reflected by the optical component.