JPH0639575A - Laser beam machine - Google Patents

Abstract

PURPOSE:To uniformly heat a material to be machined even when the material is moved in any direction and to obtain good machined quality in a laser beam machine using a kaleidoscope. CONSTITUTION:A cylindrical body 9 wherein the kaleidoscope 11 is incorporated can be rotated by a drive motor 17 round an optical axis of the laser beam 7. A material 21 to be machined is arranged on an XY table 4 and irradiated with laser beam 7. A drive motor controller 6 monitors a controlled content of a NC controller 5 to detect the moving direction (angle) of the XY table 4 and a drive motor 17 is started to rotate the cylindrical body 9. In this way, the kaleidoscope 11 is always driven and controlled so that an arbitrary one side of the rectangular laser beam 7 formed by the kaleidoscope 11 becomes vertical or parallel to the moving direction of the material 21 to be machined.

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,
More specifically, the present invention relates to a laser processing apparatus for processing a work by irradiating the work with a uniform intensity distribution of laser light emitted from a laser oscillator by a kaleidoscope.

[0002]

2. Description of the Related Art Conventionally, a laser processing apparatus of this kind has been used for subjecting a work to heat treatment such as quenching. An example of such a device will be described with reference to FIG.

A laser beam 52 output from a laser oscillator 51 is redirected by a reflecting mirror 53, condensed by an incident lens 54, and then incident on a kaleidoscope 55. The kaleidoscope 55 includes four plane reflecting mirrors 56.
Is configured in the shape of a quadratic prism, and the inner surface of the quadratic prism serves as a reflecting mirror, and the laser light 52 has a uniform intensity distribution by multiple reflection inside the kaleidoscope 55, It becomes a rectangular shape. The laser light 52 emitted from the kaleidoscope 55 is irradiated onto the workpiece 58 with a predetermined size by the imaging lens 57.

The work piece 58 is arranged in the moving device 59 and can move relative to the laser beam 52. A graphite-based laser light absorber 60 for increasing the absorptance of the laser light 52 is applied to the surface of the workpiece 58.
The workpiece 58, which has been rapidly heated to the quenching temperature by the irradiation of the laser beam 52, is rapidly cooled by the heat conduction to the inside, and the quench-hardened layer 61 is formed.

In heat treatment such as quenching, it is desirable to make the intensity of the laser beam 52 uniform in this way, and the above-mentioned conventional method using the kaleidoscope 55 has a simpler structure than other methods. This has the advantage that the size of the laser beam 52 focused on the surface of the workpiece 58 can be adjusted relatively easily.

In the laser processing apparatus having such a structure, the kaleidoscope 55 is fixed to the laser processing apparatus. Therefore, for example, when the workpiece 58 is moved in parallel or in the vertical direction relative to an arbitrary side of the laser light 52 that is irradiated in a rectangular shape as shown in FIG. Be heated.

[0007]

However, when the workpiece 58 is moved in a direction different from the above as shown in FIG. 8, the following problems occur. That is, as shown in FIG. 7, when the workpiece 58 is moved relative to one side of the laser light 52 in parallel or perpendicularly, any two points through which the rectangular laser light 52 passes, point A While the irradiation time of the laser light at the points B and B is the same, as shown in FIG. 8, the workpiece 58 is moved relative to any one side of the laser light 52 in a direction other than the parallel or vertical direction. In such a case, the irradiation time of the laser light at two arbitrary points, point A and point B, through which the rectangular laser light 52 passes is obviously different. Therefore, the workpiece 58 becomes non-uniformly heated, and the quench-hardened layer 61 is formed in a non-uniform state.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to uniformly heat the workpiece to be moved no matter which direction it is, and it is possible to obtain good processing quality by laser processing. The purpose is to provide a device.

[0009]

In order to achieve this object, a laser processing apparatus of the present invention uses a kaleidoscope to make the intensity distribution of laser light emitted from a laser oscillator uniform and then irradiates the object to be processed. By doing so, in the laser processing apparatus for processing the workpiece, the moving means for supporting the workpiece so as to be relatively movable with respect to the laser light, and the kaleidoscope for the optical axis of the laser light. A rotation supporting means for rotatably supporting the apparatus main body as a center, a driving means for rotating the rotation supporting means with respect to the apparatus main body, and the driving means based on the relative movement direction of the workpiece by the moving means. And a control means for controlling.

[0010]

According to the laser processing apparatus of the present invention having the above structure, the intensity distribution of the laser light is made uniform by the kaleidoscope, and the work is irradiated with the laser light having a rectangular shape.
The kaleidoscope can rotate with respect to the apparatus main body about the optical axis of the laser light by the rotation supporting means and the driving means thereof. The control means recognizes the moving direction of the workpiece with respect to the laser light based on the operation of the moving means in which the workpiece is arranged, and based on the result, the rectangular laser light formed by the kaleidoscope is used. The driving means is driven so that any one side is parallel or perpendicular to the moving direction of the workpiece.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, referring to FIG. 1 and FIG. 2, an outline of a laser processing apparatus embodying the present invention will be described.

The laser processing apparatus of this embodiment comprises a CO ₂ laser oscillator 1, a reflecting mirror 2, a processing head 3, an XY table 4, an NC controller 5 and a drive motor controller 6. The laser light 7 output from the CO ₂ laser oscillator 1 has a wavelength of 10.6 μm (micrometer). Further, the reflecting mirror 2 and the processing head 3 are arranged on the optical axis of the laser light 7.

An entrance lens 8, a cylinder 9 and an imaging lens 10 are arranged in the processing head 3, and a kaleidoscope 11 is built in the cylinder 9. The kaleidoscope 11 is formed by arranging four plane reflecting mirrors 12 in a quadrangular prism shape, but has a structure in which the inner surfaces of the quadrangular prisms are reflecting mirrors.

The cylindrical body 9 as the rotation supporting means of the kaleidoscope 11 is supported by the processing head 3 by the bearing 14 and the holding portion 15. The center of gravity of the kaleidoscope 11 and the central axis of the cylindrical body 9 are arranged so as to coincide with the central axis of the laser beam 7, and the center axis of the laser beam 7 can be rotated.

Further, the processing head 3 is provided with a drive motor 17 as a drive means for rotating the cylindrical body 9. The drive motor 17 and the tubular body 9 include a pulley 18 on the outer surface of the tubular body 9 and a pulley 19 on the output end of the drive motor 17.
And the timing belt 20.

A well-known XY table 4 which is a moving means is arranged below the processing head 3, and a workpiece 21 is arranged on the XY table 4. The workpiece 21 is an iron-based material, and the surface thereof is coated with a graphite-based laser light absorber 22 for increasing the absorption rate of the laser light 7.

The XY table 4 includes an X-direction rotating shaft and a Y-direction rotating shaft (not shown), and rotates the X-direction rotating shaft and the Y-direction rotating shaft by an NC controller 5 including a well-known motor or the like. By doing so, it is possible to move in a desired direction. In this way, the workpiece 21 on the XY table 4 is moved relative to the laser light 7 to complete the machining of the workpiece 21. Further, the NC control device 5 and the drive motor 17 are connected by a drive motor control device 6 which is a control means.

Next, with reference to FIGS. 3 to 5, the state of quenching using the laser processing apparatus of the present invention will be described.

The laser light 7 emitted from the CO ₂ laser oscillator 1 is circular and has an intensity distribution such that the intensity of the laser light increases toward the center thereof. The laser light 7 is redirected by the reflecting mirror 2 arranged on the optical axis thereof, and then enters the incidence lens 8 in the processing head 3. The laser light 7 condensed by the incident lens 8 enters from the input end 23 of the kaleidoscope 11 and is reflected by the flat reflecting mirror 12
After being multiple-reflected by, the light is emitted from the output end 24.
Then, the workpiece 21 is imaged by the imaging lens 10.
Is irradiated on the surface of. At this time, the laser light 7 becomes rectangular due to the influence of the shape of the kaleidoscope 11, and the intensity distribution of the laser light 7 is also made uniform. The size of the laser light 7 emitted from the kaleidoscope 11 is determined by the characteristics of the respective components of the incident lens 8, the kaleidoscope 11, and the imaging lens 10, the distance between the respective components, and the like. It is to be adjusted to the dimensions.

When the surface of the work piece 21 is irradiated with the laser light 7, the surface of the work piece 21 is rapidly heated to the quenching temperature. In addition, the workpiece 21 has an NC XY table 4.
Since it moves as it moves by the control device 5,
The portion irradiated with the laser light 7 is not irradiated with the laser light 7 after the elapse of a predetermined time. Therefore, the heated portion is rapidly cooled by heat conduction to the inside of the workpiece 21, and becomes the quench-hardened layer 25. By continuing the above process, quenching of a predetermined pattern is completed.

At this time, for example, as shown in FIG. 4, when the XY table 4 moves only in the X direction, an arbitrary side 26 of the laser beam 7 formed on the workpiece 21 is moved in the moving direction. Parallel. As a result, the irradiation time of the laser light at any two points on the work piece 21, through which the rectangular laser light 7 passes, point A and point B, is the same, and the laser light is uniformly heated. The obtained quench-hardened layer 25 is uniform.

Next, consider the case where the XY table 4 moves at an angle of +45 degrees with respect to the movement of the workpiece 21 shown in FIG. 4, as shown in FIG.

When the XY table 4 is moved by the NC control device 5 as described above, the drive motor control device 6 operates in the X direction.
The movement direction (angle) is detected from the movement amounts of the Y table 4 in the X direction and the Y direction, the drive motor 17 is driven based on the detected angle, and the kaleidoscope 11 is centered on the optical axis of the laser light 7 by +45. Rotate it once. As a result, the arbitrary side 26 of the laser light 7 formed on the workpiece 21 is
As shown in FIG. 5, it becomes parallel to the moving direction. As a result, the irradiation time of the laser light 7 at the arbitrary two points, point C and point D, on the workpiece 21 through which the rectangular laser light 7 passes becomes the same, and the surface of the workpiece 21 is heated uniformly. Therefore, the quench-hardened layer 25 obtained by this irradiation becomes uniform.

As described above, even if the NC control device 5 controls the XY table 4 to move in any direction, the drive motor control device 6 always drives the drive motor 17 to move the kaleidoscope 11 in place. Rotate. This allows
Arbitrary side 2 of laser light 7 formed on workpiece 21
Since 6 follows so as to be always parallel to the moving direction of the XY table 4, the workpiece 21 can be heated uniformly and, as a result, uniform processing quality can be obtained.

The present invention is not limited to the embodiments described in detail above, and various modifications can be made without departing from the spirit of the invention.

For example, as a means for moving the work piece 21, the laser beam 7 may be moved relative to the work piece 21. That is, the structure may be such that the processing head 3 moves with respect to the fixed workpiece 21.

The entrance lens 8 and the imaging lens arranged before and after the kaleidoscope 11 may be optical components having the same function. Furthermore, even if these optical components are connected to the kaleidoscope 11 and are configured to be interlocked by the drive motor 17, the effect of the present invention is not affected.

[0029]

As is apparent from the above description, according to the laser processing apparatus of the present invention, no matter which direction the workpiece is moved, the kaleidoscope forms an image on the workpiece. It is possible to make the shape of the laser light always follow the movement direction. As a result, the object to be processed can be heated uniformly, and uniform processing quality can be obtained, which is a significant industrial effect.

[Brief description of drawings]

FIG. 1 is a sectional view showing an outline of a laser processing apparatus embodying the present invention.

FIG. 2 is a cross-sectional view showing details around a processing head of the laser processing apparatus according to the present embodiment.

FIG. 3 is a schematic view showing a state of quenching processing using the laser processing apparatus of this embodiment.

FIG. 4 is a plan view showing a state of quenching processing using the laser processing apparatus of this embodiment.

FIG. 5 is a plan view showing a state of quenching processing using the laser processing apparatus of this embodiment.

FIG. 6 is a sectional view showing an outline of a conventional laser processing apparatus.

FIG. 7 is a plan view showing a state of quenching processing using a conventional laser processing apparatus.

FIG. 8 is a plan view showing a state of quenching processing using a conventional laser processing apparatus.

[Explanation of symbols]

1 CO ₂ Laser Oscillator 3 Processing Head 4 XY Table 5 NC Control Device 6 Drive Motor Control Device 7 Laser Light 9 Cylindrical Body 11 Kaleidoscope 17 Drive Motor 21 Workpiece

Claims (1)

[Claims] 1. A laser processing apparatus for processing a work by irradiating the work with a uniform intensity distribution of laser light emitted from a laser oscillator by means of a kaleidoscope. A moving means for supporting the kaleidoscope so as to be movable relative to the laser light, a rotation supporting means for rotatably supporting the kaleidoscope with respect to the apparatus main body about the optical axis of the laser light, and the rotation supporting means. A laser processing apparatus comprising: drive means for rotating the apparatus body; and control means for controlling the drive means based on the relative movement direction of the workpiece by the moving means.