JPH0241154Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Field of industrial application) The present invention relates to a laser surface treatment device that uses a laser beam to improve the surface characteristics of a workpiece.
More specifically, the present invention relates to an apparatus for hardening the surface of a workpiece.

(Prior technology) Laser hardening technology, which irradiates the workpiece surface with a laser beam to rapidly heat the workpiece surface and form a hardened layer by self-cooling the workpiece, has the following advantages: It has the following characteristics: thermal deformation of the shape at the time of insertion is extremely small, and no oil, water, etc. are required for cooling.

By the way, conventionally, when hardening the surface of a workpiece, defocusing or the like is performed so that the spot diameter becomes a predetermined diameter. Further, the cross-sectional shape of the laser beam has generally been circular. Furthermore, data on the machining position and machining conditions of the workpiece are input each time depending on the workpiece.

(Problems to be Solved by the Invention) When hardening the surface of a workpiece by defocusing, the spot diameter of the laser beam on the surface of the workpiece must always be constant. Therefore, there is a problem in that the distance between the condensing lens for forming the laser beam spot and the processing surface of the workpiece tends to change, making it difficult to uniformly harden the workpiece.

In addition, since the cross-sectional shape of the laser beam is circular, when hardening the outer circumferential surface of a cylinder, for example, the hardening start position and end position will be in a manner where the arcs touch, so the hardening start position and end position will be in contact with each other. The boundary becomes constricted and the quenched width becomes narrow. Therefore, by overlapping the quenching start position and end position so that the quenching width is approximately constant, the quenching start position will be heated twice, at the start and end of quenching, resulting in a qualitatively uniform There was a problem in that it was difficult to harden.

Furthermore, setting machining conditions and the like each time depending on the workpiece poses a problem in achieving unmanned machining. Therefore, it is possible to use an appropriate sensor to detect the machining position of the workpiece and set the machining conditions each time, but this has the problem that setting the machining conditions takes time and is inefficient. .

The present invention has been made in view of the above-mentioned problems.

[Structure of the invention] (Means for solving the problems) In order to solve the conventional problems as mentioned above,
The present invention includes a work table that supports a workpiece to be surface-treated, a laser oscillator that oscillates a laser beam to irradiate the workpiece, and a cross-sectional shape of the laser beam oscillated from the laser oscillator that is transformed into a desired cross-sectional shape. At the same time, a beam deforming means for substantially uniformizing the intensity distribution of the beam within the cross-sectional shape, a collimating means for collimating the laser beam that has passed through the beam deforming means, and a collimating means for converting the collimated laser beam into a parallel beam, which is used to process the workpiece. a processing head that irradiates the surface to be processed, an imaging device that images the workpiece in order to obtain processing position data of the workpiece, and a memory device that stores data on the processing position and processing conditions of the workpiece in advance. It is something.

(Function) With the above configuration, the laser beam oscillated from the laser oscillator is collimated and irradiated onto the workpiece, so even if the distance between the processing head and the workpiece changes, the laser beam emitted from the laser oscillator will not reach the workpiece. The energy density of the irradiated part is constant. Therefore, uniform hardening can be performed on the surface of the workpiece.

As mentioned above, when irradiating a workpiece with a laser beam, the cross-sectional shape of the laser beam is formed to have a parallel portion in one part, and the intensity distribution of the beam within the cross-sectional shape is made almost uniform. In addition to being able to perform hardening over a wide range, the entire hardening width can be made uniform without overlapping the hardening start and end positions.

In addition, when performing laser hardening on a workpiece, the processing position is determined by imaging the workpiece using an imaging means, comparing it with a processing pattern previously stored in the memory means, and selecting the processing position and processing conditions. Perform laser hardening.

(Actual example) Referring to FIGS. 1 and 2, a laser surface treatment apparatus 1 according to this example includes a work table 3 that supports a workpiece W to be surface-treated. A laser oscillator 5 that oscillates a laser beam LB to irradiate the workpiece W is provided at a side position. Since this laser oscillator 5 may be of a general type, a detailed explanation thereof will be omitted.

The work table 3 is moved in the X-axis direction (see Figs. 1 and 2) by driving an A movable table 7 that is moved and positioned in the horizontal direction)
The rotary table 9 is supported by a movable table 7 and is horizontally rotatable by driving a servo motor (not shown) for turning and indexing. The workpiece W is horizontally mounted on the rotary table 9 via a suitable fixture, such as a magnetic chuck (not shown). In this example, the work W is illustrated as a disk having holes H at an appropriate number of locations.

In the above configuration, the desired hole H of the work W can be positioned at a predetermined position by automatically performing the movement positioning of the movable table 7 and the rotation and rotational positioning of the rotary table 9 under the control of the NC device. It is.

As can be understood from FIGS. 1 and 2, a column 11 is provided upright at a side position of the movement area of the work table 3. A guide member 13 extending across the Y-axis direction is supported in a cantilevered manner. A processing head 15 that irradiates a desired position of the workpiece W with a laser beam LB from the laser oscillator 5 is supported on the guide member 13 so as to be movable in the Y-axis direction. This processing head 15
is the servo motor SM attached to the column 11.
It is moved and positioned in the Y-axis direction by driving.

With the above configuration, the processing head 15 is moved and positioned in the Y-axis direction to correspond to the desired position of the workpiece W, and the workpiece W is irradiated with the laser beam LB from the laser oscillator 5, thereby hardening the desired position of the workpiece W. It will be understood that it can be done.

By the way, when performing laser hardening on the surface of the workpiece W, if the reflectance of the workpiece surface is high, it is necessary to perform an appropriate coating treatment on the workpiece surface. Therefore, in this practical example,
A surface coating device 16 is located on the side of the movement area of the work table 3. This surface coating device 16 acts to apply a suitable coating material such as manganese phosphate, carbon powder, silicon carbide, etc. to the desired surface of the workpiece W, and may be composed of, for example, a general coating robot or the like. be.

When performing laser hardening on a desired location of the workpiece W, in order to make the cross-sectional shape of the laser beam LB the desired cross-sectional shape and to make the intensity distribution of the beam approximately uniform within the cross-sectional shape to uniformly perform laser hardening, The processing head 13 is provided with beam deforming means. In addition, the processing head 13
An imaging device 17 such as a CCD camera, for example, is installed as an imaging means for detecting the number and arrangement pattern of holes H previously drilled in the workpiece W.

More specifically, as shown in FIG. 3, a vertical support plate 19 is provided within the processing head 13, and the beam deformation means is provided on this support plate 19. That is, a first bend mirror 21 is mounted on the support plate 19 to reflect the laser beam LB emitted from the laser oscillator 5 downward. Further, near the lower part of the support plate 19, an integration mirror 23 is mounted in correspondence with the first bend mirror 21 so that the direction of reflection can be finely adjusted.

The integration mirror 23 changes the cross-sectional shape of the laser beam LB from the laser oscillator 5.
In this practical example, the laser beam LB is transformed from a round shape to a square shape, and the beam intensity distribution within the cross-sectional shape of the laser beam LB is made almost uniform.
A large number of rectangular plane mirrors 27 are mounted on a concave substrate 25. That is, a large number of plane mirrors 27
are appropriately arranged so that the focal plane has a rectangular shape and the beam intensity is uniform. Therefore, in other words, at the focal plane of the integration mirror 23, the laser beam
The cross-sectional shape of the LB is square, and the beam intensity is uniform over the cross-sectional area. Note that the focal length of the integration mirror 23 is set to be large.

In the integration mirror 23,
Support plate 29 supporting concave substrate 25
supports the support plate 1 through a plurality of springs 31 and a plurality of bolts 33, each biased in a different direction.
It is swingably supported by a bracket 35 attached to 9. Further, the support plate 29 is
It is supported by a plurality of micrometers 37 attached to a bracket 35 for fine adjustment. Therefore, by operating the micrometer 37, the direction of reflection of the laser beam LB can be finely adjusted.

Furthermore, a second bend mirror 39 is attached near the top of the support plate 19. This second bend mirror 39 reflects the laser beam LB from the integration mirror 23 vertically downward, and is provided so that the reflection direction can be finely adjusted. The configuration for finely adjusting the second bend mirror 39 includes the integration mirror 23
The configuration is similar to that of .

At the lower position of the second bend mirror 39,
A concave lens 41 is arranged as a collimating means for collimating the laser beam LB. The focal position of this concave lens 41 is aligned with the focal point of the integration mirror 23. Therefore, the laser beam LB passing through the concave lens 41 becomes a parallel light beam with a square cross section and is irradiated vertically downward.

In order to irradiate the laser beam LB onto the peripheral surface of the workpiece W or the inner peripheral surface of the hole H of the workpiece W, a bend mirror 43 is provided at the lower end of the concave lens 41 to horizontally reflect the laser beam LB. A mirror support member 45 is supported so as to be vertically movable and horizontally rotatable.

More specifically, as shown in FIG. 4, a threaded rod 49 such as a ball screw is vertically and rotatably supported on the back surface of the support plate 19 via a bearing block 47. Lifting bracket 53 equipped with a nut member 51 screwed into this threaded rod 49
is guided and supported by a guide member 55 vertically provided on the back surface of the support plate 19 so as to be vertically movable. Therefore, the screw rod 49 and the output shaft are connected,
The lifting bracket 53 is moved up and down by driving a servo motor 57 mounted on the support plate 19.

The mirror support member 45 is attached to a support bracket 59 horizontally attached to the lower part of the lift bracket 53.
is supported. That is, the support bracket 59 extends to a position that crosses the optical path of the vertical laser beam LB, and a through hole 61 is bored at a position corresponding to the laser beam LB. A flange member 65 having a boss portion 63 in the center is attached to the lower surface of the support bracket 59, and a cylindrical outer cylinder member 67 is attached to the lower part of the flange member 65.
is installed. An annular inner cylinder member 69 is rotatably supported inside the outer cylinder member 67.

A driven pulley 71 rotatably supported by the boss portion 63 of the flange member 65 is integrally attached to the upper part of the inner cylinder member 69. A belt 73 that is wound around the driven pulley 71 is wound around a drive pulley 77 that is attached to a motor 75 that is attached to the support bracket 59. An annular member 8 provided with an annular water cooling chamber 79 at the lower part of the inner cylindrical member 69
1 is integrally attached, and the pipe-shaped mirror support member 45 is attached to the lower part of this circular member 81.

A mirror base member 83 made of a material with good thermal conductivity, such as copper, is attached to the lower part of the mirror support member 45, and the bend mirror 43 is supported on this mirror base member 83. In this example, the bend mirror 43 is held at an angle of 45 degrees, and the mirror support member 45
An exit of the laser beam LB reflected by the bend mirror 43 is formed in a part of the mirror 43 .

In order to cool the bend mirror 43, a heat pipe 85 is supported on the mirror support member 45. One end of this heat pipe 85 is
The heat pipe 85 is in contact with the mirror base member 83 and the bend mirror 43, and the other end of the heat pipe 85 faces into the water cooling chamber 79. Therefore,
The bend mirror 43 is effectively cooled.

As shown in FIG. 5, the imaging device 17
is connected to the CPU via the imaging interface 87.
It is connected to 89. The CPU 89 is connected to the RAM 91 and ROM 93 via a data bus, and also connects an interface 95 to the NC
It is connected to device 97.

When the workpiece W is imaged by the imaging device 17, in step S1 shown in FIG.
The image is loaded into the CPU 89. and,
The image data of the work W taken into the CPU89 is
It is stored in RAM91. Furthermore, after capturing the image, the CPU 89 decodes the arrangement pattern of the holes H in the workpiece W (step S2).
A comparison is made with each arrangement pattern previously stored in the ROM 93, and data on the same arrangement pattern and the machining position and processing conditions corresponding to this arrangement pattern are fetched. Then, by outputting the processing data to the NC device 97 via the interface 95 (step S3), the workpiece W is automatically laser hardened under the control of the NC device 97.

By the way, in the above configuration, the imaging device 17 is positioned above the workpiece W placed on the worktable 3 to capture an image of the workpiece W.
After that, the hole H of the workpiece W and the mirror support member 45 are
are automatically opposed. Then, the lifting bracket 53 is automatically lowered by driving the servo motor 57, and the lower part of the mirror support member 45 is aligned with the hole H.
automatically inserted into. After the mirror support member 45 is inserted into the hole H of the workpiece W and positioned at a predetermined position, a laser beam is emitted from the laser oscillator 5.
When the LB is automatically oscillated, the laser beam LB is transformed into a parallel beam having a rectangular cross section by the integration mirror 23 and the like, and then enters the bend mirror 43. Therefore, it is reflected by the bend mirror 43 and illuminates the inner peripheral surface of the hole H.

When the laser beam LB irradiates the inner peripheral surface of the hole H,
The motor 75 is driven, the mirror support member 45 is rotated, and the laser beam LB goes around the inner peripheral surface of the hole H. Therefore, the inner peripheral surface of the hole H of the workpiece W can be hardened.

Furthermore, by arranging the mirror support member 45 to face the outer peripheral surface of the workpiece W and irradiating the outer peripheral surface with the laser beam LB while rotating the workpiece W, the outer peripheral surface of the workpiece W can be laser hardened.

As mentioned above, when laser hardening the inner circumferential surface of the hole H of the workpiece W or the outer circumferential surface of the workpiece W, since the laser beam LB is made into a parallel beam, the distance between the bend mirror 43 and the irradiation position of the workpiece W is Even if there is a change, the change in the irradiation width is extremely small, and the irradiation surface is heated uniformly, making it possible to easily perform homogeneous hardening. In addition, since the laser beam LB has a rectangular cross-sectional shape, the hole H in the work W
When hardening the inner circumferential surface or outer circumferential surface of the steel, by making the hardening start position and the hardening end position contact each other without overlapping each other, uniform hardening can be performed with a uniform hardening width.

Note that the present invention is not limited to the above-described embodiments, but can be implemented in other embodiments by making appropriate changes.

[Effects of the invention] As understood from the description of the embodiments above, according to the invention, the laser beam is collimated and then irradiated to a desired position on the workpiece.
The irradiation width of the workpiece is always approximately constant, and the irradiation surface is uniformly heated, making it possible to easily harden the workpiece uniformly. Further, when laser hardening the outer circumferential surface of a cylinder, the inner circumferential surface of a hole, etc., the entire hardening can be performed with a uniform width without overlapping the hardening start position and end position.

Furthermore, prior to laser hardening the workpiece, the hole arrangement pattern of the workpiece is decoded, and laser hardening is performed based on the pre-stored data of the processing position and processing conditions of the arrangement pattern, so the hole arrangement can be made in many different ways. Even when irregularly laser hardening a workpiece, the process can be performed accurately, reliably, and efficiently.

[Brief explanation of drawings]

FIG. 1 is a front view of the apparatus according to this embodiment, and FIG. 2 is a plan view thereof. Figure 3 is - in Figure 1.
FIG. 4 is an enlarged cross-sectional view taken along the line, and is a left side view of FIG. 3, with a portion omitted. FIG. 5 is a block diagram of the embodiment, and FIG. 6 is a flowchart. 3...Work table, 5...Laser oscillator,
13... Processing head, 17... Imaging device, 23...
...Integration mirror, 41...Concave lens.

Claims (1)

[Scope of utility model registration request] A work table that supports a workpiece to be surface-treated; a laser oscillator that emits a laser beam to be irradiated to the workpiece; and a cross-sectional shape that transforms the cross-sectional shape of the laser beam emitted from the laser oscillator into a desired cross-sectional shape. a beam deforming means for substantially uniformizing the intensity distribution of the beam within the beam, a collimating means for collimating the laser beam that has passed through the beam deforming means, and irradiating the parallelized laser beam onto the surface of the workpiece to be processed. A processing head for processing the workpiece, an imaging means for capturing an image of the workpiece in order to obtain data on the processing position of the workpiece, and a memory means for storing data on the processing position and processing conditions of the workpiece in advance. Laser surface treatment equipment.