JPH08132259A - Laser machining method and device therefor - Google Patents

Abstract

PURPOSE: To provide a laser machining method and its device which are capable of forming a body with a minute arbitrary shape from a desired material without limiting the material to be machined. CONSTITUTION: A measuring laser beam for measuring the surface shape of an object 10 to be machined and a machining laser beam for removing a surface substance with the irradiation on the surface of the object 10 are converged on the surface of the object 10 by means of the same condensing lens 38. The converging point on the surface of the object 10 is scanned on the surface and also, while the converging point is moved successively by steps from the surface to the inner part of the object 10, in accordance with the surface shape of the object 10 measured by the measuring laser beam, only a substance at a desired part is removed from the surface by the irradiation of the machining laser beam to form the object 10 into the desired cubic shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing method and a laser processing apparatus, and more particularly, to a laser processing method capable of forming a solid of an arbitrary shape from a desired material such as a metal or an organic resin. The present invention relates to a laser processing apparatus, which is particularly suitable for use in forming a small solid having a desired shape at high speed, and can be used for micromachining (micromachining).

[0002]

2. Description of the Related Art Conventionally, as a processing method for forming an arbitrary three-dimensional shape from a desired material such as a metal or an organic resin, for example, machining with a blade using a machine lathe or the like is known. It has been known.

[0003] In machining with such a blade,
It is difficult to control the position of a tool with a large inertia at high speed, and there is a limit to improving the accuracy of the tool itself.
There is a problem that a minute object having a side of about 1 mm or less cannot be processed.

[0004] In particular, when a mechanical lathe is used, a problem has been pointed out that a three-dimensional shape that can be processed is limited to a rotating body, so that an arbitrary shape cannot be processed.

[0005] As a processing method for processing a metal material to form an arbitrary three-dimensional shape, in addition to the above-described machining using a mechanical lathe or the like, electric discharge machining is generally performed. It is known that a minute three-dimensional shape can be machined by electric discharge machining.

[0006] However, such an electric discharge machining inherently has a problem that a material to be processed is limited to a conductive material.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned various problems of the prior art, and has as its object to limit the desired material without limiting the material to be processed. It is an object of the present invention to provide a laser processing method and a laser processing apparatus capable of forming a three-dimensional object having an arbitrary small shape from a laser.

[0008]

In order to achieve the above object, a laser processing method and a laser processing apparatus according to the present invention use a laser beam (pulse laser beam) instead of a conventional blade in machining such as a mechanical lathe. And a continuous laser beam.
In the case of pulsed laser light, the wavelength may be any wavelength. ) Is the material to be processed (hereinafter, referred to as “workpiece”)
Condensate on the top and remove the substance by the laser beam irradiation effect at the focal point (This substance removal is laser evaporation or laser etching when pulsed laser light is applied, and continuous laser light irradiation Is carried out by laser melting, etc.), and the workpiece is formed into an arbitrary shape by removing such a substance.

[0009]

[Function] By controlling the portion of the workpiece to be irradiated with the laser beam, it is possible to remove a substance at an arbitrary location on the workpiece, and it is possible to form not only a rotating body but also a solid body having an arbitrary shape. Become like

Further, the laser light is focused on a minute point on the workpiece, and the intensity of the laser light (in the case of pulsed laser light, the amount of light per pulse, the number of irradiation pulses, etc. In this case, the average amount of light, irradiation time, etc.) can be controlled, so that the amount of the material removed by the removal of the material by the irradiation effect of the laser beam can be accurately controlled. The shape can be formed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a laser processing method and a laser processing apparatus according to the present invention will be described below in detail with reference to the drawings. The laser processing apparatus according to the present invention can be installed not only in a vacuum but also in the air or liquid, and there is no limitation on the installation place.

FIG. 1 is a schematic structural explanatory view of a laser processing apparatus according to a first embodiment for performing a laser processing method according to the first embodiment of the present invention.

The laser processing apparatus according to the first embodiment is used in the air,
Is provided with a vertical movement stage 12 on which the. The vertical movement stage 12 is attached to the base 14 so as to be vertically movable, and can be moved in the vertical direction which is the optical axis direction of the laser light 16 described later by the operation of a drive system (not shown). The focal point of the laser light 16 condensed by the condensing lens 38 can be positioned at a predetermined portion of the workpiece 10.

The laser beam 16 radiated from above onto the workpiece 10 from above is generated by a laser irradiation system 18.

The laser irradiation system 18 includes a processing laser 20 and a light amount controller for adjusting the amount of processing laser light emitted from the processing laser 20 to adjust the amount of material removed from the workpiece 10. 22, a correction optical system device 24 for adjusting the focal position of the processing laser light,
A surface shape measuring device 26 that incorporates a measuring laser that emits a weak measuring laser beam and measures the shape of the surface of the workpiece 10 in real time, and a workpiece 10 measured by the surface shape measuring device 26 in real time. Based on the shape information indicating the surface shape of the object and the shape information indicating the target three-dimensional shape to be formed by the processing stored in advance, to compare them to obtain the target three-dimensional shape to be formed by the processing And a control device 28 that controls the light amount adjuster 22 based on the light amount control information so that the light amount of the processing laser light required for the calculation is calculated and the light amount of the processing laser light becomes the calculated light amount. I have.

The processing laser light emitted from the correction optical system 24 is reflected by the semi-transmissive mirror 30 and is incident on the total reflection mirror 32, and is reflected by the total reflection mirror 32 and is incident on the movable mirror pair 34. You.

On the other hand, the measuring laser light emitted from the surface shape measuring device 26 is reflected by the total reflection mirror 36 and is incident on the semi-transmissive mirror 30, further transmitted through the semi-transparent mirror and reflected by the total reflection mirror 32. Then, the light enters the movable mirror pair 34.

The processing laser light and the measurement laser light reflected by the movable mirror pair 34 are condensed as laser light 16 on the surface of the workpiece 10 by the condenser lens 38.

The pair of movable mirrors 34
6 is a device for scanning the X.6 at high speed in the X-Y direction, but a detailed description is omitted because it is a known technology.

The condenser lens 38 includes a movable mirror pair 3
4 so that the laser beam 16 scanned at a high speed in the X-Y direction can always be focused in the best condition.
The laser 16 can be moved at a high speed in the XY direction according to the scanning in the XY direction by the laser 16.

The correction optical system device 24 is used to adjust the focal positions of the processing laser beam and the measurement laser beam which are condensed by using the same condensing lens 38 so as to match the surface of the workpiece 10. To adjust the focal position of the processing laser light to coincide with the focal position of the measuring laser light in order to match the focal position in the optical axis direction between the processing laser light and the measuring laser light. This is a device, and may not be provided if the processing laser light and the measurement laser light have the same focal position in the optical axis direction in advance.

The movable mirror pair 34 and the condenser lens 38
The vertical movement stage 12 can be moved to a position necessary for obtaining a target three-dimensional shape to be formed by processing through a drive system (not shown) under the control of the control device 28. That is, in order to obtain a target three-dimensional shape to be formed by processing from the workpiece 10, the workpiece 10
The control device 28 controls the movement of the movable mirror pair 34, the condenser lens 38, and the vertical movement stage 12 so that the focal point of the laser light 16 is located at the site where the substance should be removed from the surface.

In the above configuration, the processing laser light emitted from the processing laser 20 constituting the laser light 16 is incident on the light quantity controller 22 and is corrected by the correction optical system device 2.
4 → semi-transmissive mirror 30 → total reflection mirror 32 → movable mirror pair 34 → condensing lens 38
By the control of 8, a predetermined position on the surface of the workpiece 10 is focused and irradiated.

At this time, when a pulse laser is used as the processing laser 20, for example, the light amount adjusted by the light amount controller 22 is obtained by laser evaporation or laser etching by the irradiation effect of the processing laser light. A corresponding amount of material will be removed from the surface of the workpiece 10 focused by the laser light 16.

At the same time, the measuring laser light emitted from the measuring laser of the surface shape measuring device 26 constituting the laser light 16 is also changed from the total reflection mirror 36 to the semi-transmission mirror 30.
→ Total reflection mirror 32 → Movable mirror pair 34 → Condensing lens 3
Through the path 8, the surface of the workpiece 10 is focused and irradiated by the control of the control device 28.

The measuring laser beam is applied to the workpiece 1
The light is reflected by the zero surface and is incident on the surface shape measuring device 26 via a path opposite to the above, that is, a path of the movable mirror pair 34 → the total reflection mirror 32 → the semi-transmission mirror 30 → the total reflection mirror 36. Thus, the surface shape measuring device 26 on which the measuring laser light reflected by the surface of the workpiece 10 is incident,
The incident measurement laser light is analyzed, the shape of the surface of the workpiece 10 is measured, and the measurement result is input to the control device 28 as shape information.

The control device 28 stores the shape information input from the surface shape measuring device 26 in this way, and stores the shape information input from the surface shape measuring device 26 and the target solid to be formed by the processing stored in advance. When it is necessary to remove a substance on the surface of the workpiece 10 by comparing the target three-dimensional shape to be formed by the processing with the current shape of the workpiece 10 based on the shape information indicating the shape, 10 A light amount controller 2 so as to emit a light amount capable of removing substances on the surface.
In addition to the control of step 2, when it is not necessary to remove the material from the surface of the workpiece 10, the light amount controller 22 is controlled so as to reduce the amount of light so that the removal of the substance from the surface of the workpiece 10 is not performed.

That is, the laser irradiation system 18 is configured to accurately obtain a target three-dimensional shape to be formed by laser processing using feedback control.

The processing laser beam and the measurement laser beam are scanned on the surface of the workpiece 10 by the operation of the movable mirror pair 34 under the control of the control device 28 as described above. The vertical movement stage 12 is moved vertically upward by the operation of a drive system (not shown) in accordance with the removal of the substance on the surface of the workpiece 10 by the processing laser light, so that the processing laser light and the measurement laser light are removed. Focusing can be performed, and laser processing with a large processing depth can be performed.

Next, as an operation example of the processing method according to the first embodiment using the laser processing apparatus according to the first embodiment, a processing method for forming a triangular pyramid on a surface of a workpiece having a flat upper surface will be described. explain. That is, a rectangular parallelepiped workpiece 100 shown in FIG. 2 is used as the workpiece, and FIG.
A processing method for forming the triangular pyramid 102 shown in FIGS.

(First Step) The vertical movement stage 12 is moved by a drive system (not shown) so that the focal point of the focus lens 38 is located on the processing surface 1 (see FIG. 2). Then, measurement laser light is emitted from the measurement laser of the surface shape measurement device 26 (the processing laser light from the processing laser 20 is not emitted), and the movable mirror pair 34 is actuated so that the measurement laser light is processed. 100, and scans the shape of the surface at each scanning point with the surface shape measuring device 2
Measured in real time by 6. Then, the measurement result is output to the control device 28 as shape information and stored in the control device 28.

In each of the steps described later, the measuring laser beam is always emitted from the measuring laser of the surface shape measuring device 26, and the shape of the surface of the workpiece 100 at each scanning point by the operation of the movable mirror 34 is changed. Shape measuring device 2
6, the light amount of the processing laser light is adjusted by controlling the light amount adjuster 22 by the control device 28 to form the triangular pyramid 102 in real time.

(Second Step) The vertical movement stage 12 is moved upward by a drive system (not shown) so that the focal point of the condenser lens 38 is located on the processing surface 2 (see FIG. 2).

(Third Step) The processing laser light is irradiated from the processing laser 20, and the processing laser light (and the measurement laser light) is processed by the movable mirror pair 34.
To remove the surface material of the workpiece 100 up to the processing surface 2 (FIG. 4A).

At this time, the processing laser light (and the measurement laser light) measured by the surface shape measuring device 26.
When the scanning point is within the cross section of the triangular pyramid 102, the controller 28 controls the light amount adjuster 22 to set the light amount of the processing laser light to “0”, and the material removal by the irradiation of the processing laser light occurs. Control not to be.

When the scanning point of the processing laser light (and the measurement laser light) measured by the surface shape measuring device 26 is outside the cross section of the triangular pyramid 102, the surface shape measured in the first stage is obtained. Based on this, the controller 28 controls the light amount controller 22 to adjust the light amount of the processing laser light, adjust the amount of material removed by irradiation of the processing laser light, and create the processing surface 2.

The working depth at each scanning point is measured in real time by the surface shape measuring device 26 in parallel with the working and output to the control device 28 for storage.

(Fourth Step) The focal point of the condenser lens is
(See FIG. 2) The vertical movement stage 12 is moved upward by a drive system (not shown) so as to be located above.

(Fifth Step) The processing laser beam is irradiated from the processing laser 20, and the processing laser beam (and the measurement laser beam) is processed by the movable mirror pair 34.
To remove the surface material of the workpiece 100 up to the processing surface 3 (FIG. 4B).

At this time, the processing laser light (and the measurement laser light) measured by the surface shape measuring device 26.
When the scanning point is within the cross section of the triangular pyramid 102, the controller 28 controls the light amount adjuster 22 to set the light amount of the processing laser light to “0”, and the material removal by the irradiation of the processing laser light occurs. Control not to be.

When the scanning point of the processing laser light (and the measurement laser light) measured by the surface shape measuring device 26 is outside the cross section of the triangular pyramid 102, the surface shape measured in the third step is obtained. Based on this, the controller 28 controls the light amount controller 22 to adjust the light amount of the processing laser light, adjust the amount of material removed by irradiation of the processing laser light, and make the processing surface 3 flat. .

The processing depth at each scanning point is measured in real time by the surface shape measuring device 26 in parallel with the processing, and is output to the control device 28 and stored.

Thereafter, the processes in the above steps may be sequentially repeated until the final processed surface n (FIG. 4C) is obtained.

The surface of the triangular pyramid 102 after the laser processing has a step-like shape as shown in FIG. 5, and this step indicates the resolution of the laser processing apparatus according to the first embodiment. It is equivalent to the focused diameter of the laser light for use. However, since this condensing diameter can be reduced to about the wavelength of the processing laser light, the step-like step shown in FIG. 5 can be made extremely small, and the processing can be performed according to the desired processing accuracy. By selecting the wavelength of the laser light for use, it becomes practically negligible.

Next, a laser processing apparatus according to a second embodiment for implementing the laser processing method according to the second embodiment of the present invention will be described.

FIG. 6 is a schematic structural explanatory view of a laser processing apparatus according to a second embodiment for carrying out the laser processing method according to the second embodiment of the present invention, which is shown in FIG. Constituent members that are the same as or correspond to those of the laser processing apparatus according to the first embodiment are denoted by the same reference numerals as those in FIG. 1, and detailed description thereof will be omitted.

The laser processing apparatus shown in FIG. 6 is mounted on a rotation device 40 which rotates the workpiece 10 at a predetermined rotation speed (angular velocity ω) under the control of the control device 28. The rotation device 40 is attached to a horizontal movement stage 42 that is reciprocated in a horizontal direction by a drive system (not shown) under the control of the control device 28. The movement of the horizontal movement stage 42 is advanced so as to advance about the processing width (laser beam spot diameter: the diameter of the condensing point of the processing laser beam on the surface of the processing object 10) during one rotation of the processing object 10. Is set.

Further, the horizontal moving stage 42 is mounted on a vertical moving stage 44, and the vertical moving stage 44 is mounted on the base 14 so as to be movable up and down. It can be moved in the vertical direction by a drive system that does not.

In the laser processing apparatus according to the second embodiment, a laser beam 1
6 is a vertical and horizontal direction relative to the workpiece 10.
The laser beam is irradiated from two directions, that is, the workpiece 10 is irradiated from two directions, that is, the vertical direction and the horizontal direction, and is generated by the two sets of laser irradiation systems 18a and 18b (however, Of the laser irradiation system 18b, the processing laser 20, the light amount controller 22,
The correction optical system device 24, the surface shape measurement device 26, the control device 28, the transflective mirror 30, and the total reflection mirror 36
It is also possible to share with the corresponding configuration of the laser irradiation system 18a. ). That is, the laser irradiation system 1
8a, a laser beam 16 that is irradiated on the workpiece 10 from the vertical direction is generated, and the laser irradiation system 1
By 8b, a laser beam 16 that irradiates the workpiece 10 from the horizontal direction is generated.

The laser irradiating systems 18a and 18b and the laser irradiating system 18 used in the laser processing apparatus according to the first embodiment have a total reflection mirror 32 and a movable mirror pair 34. The laser irradiation system 18 is different from the laser irradiation system 18 in that the processing laser light is directly incident on the condenser lens 38 via the semi-transmissive mirror 30.
Is different from

Therefore, in the laser processing apparatus according to the second embodiment, the workpiece 10 is rotated by the rotating device 40, the horizontal moving stage 42 is moved in the horizontal direction, and the vertical moving stage 44 is moved in the vertical direction. By moving, the scanning of the laser beam 16 on the workpiece 10 is realized.

Next, as a working example of the processing method using the laser processing apparatus according to the second embodiment, a processing method for forming a triangular prism by processing the side surface of a cylinder will be described. That is, the columnar workpiece 20 shown in FIG.
In the case of forming the triangular prism 202 using 0,
Each step will be described in order. Note that a laser irradiation system 18a is used for side processing of the columnar workpiece 200 described below.

(First Step) The vertical movement stage 44 is moved by a drive system (not shown) so that the focal point of the focus lens 38 is located on the processing surface 1 (see FIG. 8). Then, measurement laser light is emitted from the measurement laser of the surface shape measurement device 26 (the processing laser light from the processing laser 20 is not emitted), and the rotating device 40 is rotated and the horizontal movement stage 42 is moved. The surface of the workpiece 100 is scanned with the measuring laser light, and the surface shape at each scanning point is measured in real time by the surface shape measuring device 26. Then, the measurement result is output to the control device 28 as shape information and stored in the control device 28.

In each of the steps described below, a measuring laser beam is always emitted from the measuring laser of the surface shape measuring device 26, and the rotating device 40 is rotated, and the horizontal moving stage 42 is moved. The shape of the surface of the workpiece 200 is measured in real time by the surface shape measuring device 26, and the control device 2 is used to form the triangular prism 202.
By controlling the light amount adjuster 22 with 8, the light amount of the processing laser light is adjusted.

(Second Step) The vertical movement stage 44 is moved upward by a drive system (not shown) so that the focal point of the condenser lens 38 is located on the processing surface 2 (see FIG. 8).

(Third Step) The processing laser light is irradiated from the processing laser 20, and the processing laser light (and the measurement laser light) is applied to the surface of the workpiece 200 by the operation of the rotating device 40 and the horizontal movement stage 42. By scanning upward, the surface material of the workpiece 200 up to the processing surface 2 is removed (see FIG. 8). The relationship between the amount of the processing laser light and the rotation angle of the workpiece 200 by the rotating device 40 at this time is as shown in FIG.

At this time, the processing laser light (and the measurement laser light) measured by the surface shape measuring device 26.
When the scanning point is within the cross section of the triangular prism 202, the controller 28 controls the light amount adjuster 22 to set the light amount of the processing laser light to "0", and the removal of the substance by the irradiation of the processing laser light does not occur. Control.

When the scanning point of the processing laser light (and the measuring laser light) measured by the surface shape measuring device 26 is outside the cross section of the triangular prism 202, the scanning point is determined based on the surface shape measured in the first stage. Then, the light amount of the processing laser light is adjusted by controlling the light amount controller 22 by the control device 28, and the amount of material removed by the irradiation of the processing laser light is adjusted so that the processing surface 2 becomes a circumferential surface. I do.

The processing depth at each scanning point is measured in real time by the surface shape measuring device 26 in parallel with the processing, and is output to the control device 28 and stored.

(Fourth Step) The focal point of the condenser lens is
(See FIG. 8) The vertical movement stage 44 is moved upward by a drive system (not shown) so as to be located above.

(Fifth Step) The processing laser light is emitted from the processing laser 20, and the rotation laser 40 and the horizontal movement stage 42 are operated to apply the processing laser light (and the measurement laser light) to the surface of the workpiece 200. By scanning upward, the surface material of the workpiece 200 up to the processing surface 3 is removed (see FIG. 8). The relationship between the amount of the processing laser light and the rotation angle of the workpiece 200 by the rotating device 40 at this time is as shown in FIG. 9B.

At this time, the processing laser light (and the measurement laser light) measured by the surface shape measuring device 26.
When the scanning point is within the cross section of the triangular prism 202, the controller 28 controls the light amount adjuster 22 to set the light amount of the processing laser light to "0", and the removal of the substance by the irradiation of the processing laser light does not occur. Control.

When the scanning point of the processing laser light (and the measurement laser light) measured by the surface shape measuring device 26 is outside the cross section of the triangular prism 202, the scanning point is determined based on the surface shape measured in the third stage. The controller 28 controls the light amount adjuster 22 to adjust the light amount of the processing laser light, adjusts the amount of material removed by the irradiation of the processing laser light, and adjusts the processing surface 3 to a circumferential surface. I do.

The processing depth at each scanning point is measured in real time by the surface shape measuring device 26 in parallel with the processing, and is output to the control device 28 and stored.

Thereafter, the processes in the above steps may be sequentially repeated until the final processed surface n (see FIG. 8) is obtained.

The surface of the triangular prism 202 after the laser processing also has a step-like shape like the surface of the triangular pyramid 102 shown in FIG. 5, but this step shows the resolution of the laser processing apparatus according to the second embodiment. And is equivalent to the focused diameter of the processing laser light. However, since the condensing diameter can be reduced to about the wavelength of the processing laser light, the step-like step shown in FIG. By selecting the wavelength of the laser light, it becomes practically negligible.

Further, when processing the end face 200a or the end face 200b in the direction of the rotation axis of the rotating device 40 of the workpiece 200, laser processing may be performed using the laser irradiation system 18b in the same manner as described above. As described above, when laser processing is performed using the laser irradiation system 18b, adjustment of the focal position of the laser beam 16 on the surface of the workpiece 200 is performed by adjusting the horizontal movement stage 4
2, and the scanning of the laser beam 16 on the surface of the workpiece 200 may be performed using the rotating device 40 and the vertical movement stage 44.

In each of the above-described embodiments, since the amount of material removed by the irradiation of the processing laser beam is generally very small, it takes a long time to form a large workpiece. Become. However, since the amount of material removal required to obtain the desired shape is proportional to the cube of the representative length of the workpiece, the time required for processing is shortened accordingly, and the representative length of the target workpiece is reduced. In the case of a minute object having a diameter of 1 mm or less, a target three-dimensional shape can be obtained by laser processing in a sufficiently short time for practical use.

It is known that, when a workpiece whose mass distribution is not axially symmetric is rotated at a high speed, the deviation of the workpiece caused by the centrifugal force due to the eccentric movement causes a reduction in the processing accuracy. The relative amount of blur (blur length / representative value of the workpiece) is inversely proportional to the square of the relative amount of eccentricity (eccentric length / representative value of the workpiece). Therefore, when the workpiece is very small,
The reduction in processing accuracy due to the blur is remarkably reduced, and can be practically ignored when the representative length of the workpiece is 1 mm or less. For this reason, when the workpiece is very small, it is possible to perform accurate laser processing using various materials by using the laser processing method and the laser processing apparatus according to the present invention.

As the processing laser, the above-described pulse laser and continuous laser may be appropriately selected according to the conditions of the workpiece or the like. The removal of a substance when using a pulsed laser is laser evaporation or laser etching, and the removal of a substance when using a continuous laser is laser melting or the like.

Further, the control of the light amount by the light amount adjuster not only reduces the irradiation light amount, but also controls the operation of the optical shutter or the processing laser itself to turn on / off the laser light, thereby turning the laser light on / off. May be adjusted.

Further, the processing accuracy of the laser processing depends on the focusing diameter of the focusing lens for focusing the laser light on the surface of the workpiece as described above, and the focusing diameter is as small as the wavelength of the laser light. Therefore, when an ultraviolet laser is used, the processing accuracy can be increased to 1 μm or less.

Further, in each of the embodiments described above, the case where the laser processing apparatus is used in the air has been described. However, the laser processing apparatus may be used in a vacuum or in a liquid. For example, when the workpiece is immersed in an etchant, the continuous laser light is irradiated as the processing laser light to increase the etching effect in the continuous laser light irradiation part. Laser processing and etching by the laser processing apparatus according to the present invention act synergistically, and a solid having a desired shape can be obtained at higher speed.

Further, in the above-described second embodiment, the laser irradiation system employs a laser beam irradiation in the vertical direction and a laser beam irradiation in the horizontal direction.
Although different laser irradiation systems were used, the laser light emitted from a single laser irradiation system was appropriately branched using a single laser irradiation system, and the laser light was irradiated from the vertical direction and from the horizontal direction. May be shared with the laser light irradiation.

In the second embodiment, the work may be irradiated with laser light from an appropriate direction (angle) by using three or more sets of laser irradiation systems.

Further, in each of the above embodiments, the measuring laser beam and the processing laser beam are converged to the same condensing optical system (semi-transmissive mirror 30, total reflection mirror 32, movable mirror pair 34, total reflection mirror 36). The condensing lens 38) is used to condense the light on the surface of the workpiece. However, the present invention is not limited to this, and the laser light for measurement and the laser light for processing is separated using a separate condensing optical system. Light may be collected on the surface.

Further, in the laser irradiation system in each of the above-described embodiments, the light amount control information from the control device is supplied to the light amount adjuster, and the target three-dimensional shape to be formed by laser processing using the feedback control can be accurately determined. Although it is configured to obtain the feedback control, the feedback control is not limited to such a configuration, and another configuration may be adopted.

Further, in the laser irradiation system in each of the above-described embodiments, the light amount control information from the control device is supplied to the light amount adjuster so that the target three-dimensional shape to be formed by laser processing using the feedback control can be accurately determined. The laser irradiation system is configured so as to obtain, but is not limited thereto, the laser irradiation system may be controlled so as to perform laser processing to a preset shape without using feedback control.

As described above, when laser processing is performed without using feedback control, if a reference surface of a workpiece to be processed into a desired shape is formed with high precision in advance, high accuracy without errors can be obtained. Processing can be performed.

The laser processing method according to the present invention can also be used to form such a reference surface of a workpiece. For example, there are two methods described below.

[Horizontal Irradiation Method] For example, when a highly accurate cylinder is obtained as a workpiece for forming a desired shape, as shown in FIG. 10, a lens 300 having a relatively long focal length fl is used. The laser light for processing is condensed, and the outer edge 302 of the laser light for processing near the focal point f is set so as to contact the side surface of the workpiece 304 on the substantially column.

In the above configuration, the workpiece 304
Is rotated about the center axis O, and the laser light for processing is scanned once or repeatedly in the direction of the center axis O.
Thus, the material on the side surface of the workpiece 304 that is in contact with the outer edge 302 of the processing laser beam is removed.

Then, the processing laser beam and the workpiece 304 are relatively moved so that the outer edge 302 near the focal point f of the processing laser beam contacts the side surface of the workpiece 304,
By performing the above operation while shortening the distance l, it is possible to obtain a highly accurate cylinder whose cross section is very close to a perfect circle. That is, it is possible to obtain a workpiece 304 having a side surface whose cross section is very close to a perfect circle as a reference surface. By performing laser processing on the basis of this reference surface, high processing can be performed without performing feedback control. Accuracy can be achieved.

The lens 3 having a relatively long focal length fl
00 is the diameter d and the focal length f of the processing laser light.
It is preferable that the F value (F = fl / d) representing the relationship with 1 be 10 or more.

[Vertical Irradiation Method] For example, in order to obtain a highly accurate cylinder as a workpiece for forming a desired shape, as shown in FIG. 11, a lens 400 having a relatively short focal length fl is used. The laser beam for processing is condensed so that the optical axis of the laser beam is perpendicular to the side surface of the workpiece 404 on the substantially cylindrical shape, and the irradiation position 40 having the maximum irradiation intensity density on the focal point f
Only in Step 2, the output of the processing laser light is adjusted and set so that removal of the surface material of the workpiece 404 occurs.

In the above configuration, the workpiece 404
Is rotated about the center axis O, and the laser light for processing is scanned once or repeatedly in the direction of the center axis O.
Thus, only the surface material on the side surface of the workpiece 404 in contact with the irradiation position 402 where the focal point f of the processing laser light is located is removed.

Then, the processing laser beam and the workpiece 404 are relatively moved so that the irradiation position 402 where the focal point f of the processing laser beam is located is in contact with the side surface of the workpiece 404, and the distance 1 is reduced. By performing the above-described operation while performing the above operation, it is possible to obtain a highly accurate column having a cross section extremely close to a perfect circle. That is, it is possible to obtain a workpiece 404 having a side surface whose cross section is very close to a perfect circle as a reference surface. By performing laser processing on the basis of this reference surface, high processing can be performed without performing feedback control. Accuracy can be achieved.

The lens 4 having a relatively short focal length fl
00 is the diameter d and the focal length f of the processing laser light.
It is preferable that the F value (F = fl / d) representing the relationship with 1 is about 1.

In general, when a substance is irradiated with a laser to remove the substance, there is a threshold for the laser irradiation intensity density. In other words, if laser irradiation is performed at a laser irradiation intensity density equal to or higher than the threshold value, the substance can be removed by laser irradiation.However, even when laser irradiation is performed at a laser irradiation intensity density equal to or lower than the threshold value, the substance is irradiated by the laser irradiation. It is known that it cannot be removed.

For this reason, in the above-described horizontal irradiation method and vertical irradiation method, when it is desired to form the reference surface with higher accuracy, the laser beam for processing is applied to the workpiece at a laser irradiation intensity density slightly exceeding the threshold value. Irradiation is preferred. As described above, when the workpiece is irradiated with the processing laser light at a laser irradiation intensity density slightly exceeding the threshold value, the workpiece 304 in contact with the outer edge 302 near the focal point f of the processing laser light in the horizontal irradiation method. Can be reliably removed without affecting other parts of the workpiece 304, and in the vertical irradiation method, the focal point f of the processing laser beam f
Only the material on the surface of the workpiece 404 contacting the irradiation position 402 where is located can be reliably removed without affecting other parts of the workpiece 404.

In the above description of the horizontal irradiation method and the vertical irradiation method, the case where a columnar workpiece having a cross section of a perfect circular shape as a reference surface is formed has been described. However, a workpiece having a flat surface such as a rectangular solid or a flat plate as a reference surface can be obtained.

Further, the above-described horizontal irradiation method and vertical irradiation method are used not only for forming the reference plane of the workpiece, but also for the workpiece as in the first and second embodiments described above. It may be used to obtain a desired shape from.

In the first embodiment and the second embodiment,
When laser processing is performed without using feedback control for monitoring the processing surface of the workpiece in real time as described in the embodiment, the output of the processing laser light is monitored, and the processing laser The output of light may be controlled to improve processing accuracy.

That is, the output of a laser beam such as a processing laser beam constantly fluctuates, and if the output of the processing laser beam fluctuates during laser processing of a workpiece by the processing laser beam, this fluctuation is caused by a change in the processing surface. This will have a negative effect on the finished product. Therefore, always monitor the output of the processing laser light, at all laser processing points of the workpiece,
The integrated value of the output intensity (irradiation intensity density, irradiation intensity, etc.) of the processing laser light at the laser processing point is determined,
If this integrated value is higher than the value required to obtain a processing surface at the laser processing point, when performing laser processing at the laser processing point by the next scan of the processing laser light, the laser processing point The intensity of the output of the processing laser light is reduced to eliminate the influence of the fluctuation of the output of the processing laser light.

On the other hand, when the integrated value of the intensity of the output of the processing laser light at the laser processing point is lower than the value necessary for obtaining the processing surface at the laser processing point, the next scanning of the processing laser light is performed. When performing laser processing at the laser processing point, the intensity of the output of the processing laser light at the laser processing point is increased to eliminate the influence of the fluctuation of the output of the processing laser light.

In order to change the intensity of the output of the laser light at such a laser processing point, it is sufficient to change the amount of light per pulse and the number of irradiation pulses in the case of pulsed laser light. In that case, the average light amount, the irradiation time, and the like may be changed.

That is, to decrease the output intensity of the pulsed laser light, for example, it is only necessary to reduce the number of irradiation pulses at the laser processing point. Conversely, to increase the output intensity, the laser processing The number of irradiation pulses at a point may be increased, and such control can be easily realized by on / off control of the processing laser.

In order to reduce the intensity of the output of the continuous laser light, for example, the irradiation time at the laser processing point may be reduced. On the other hand, to increase the output intensity, the intensity of the output at the laser processing point may be reduced. The irradiation time may be increased, and such control can be easily realized by on / off control of the processing laser.

[0099]

Since the present invention is configured as described above, it has the following effects.

Instead of a cutting tool used in machining such as a conventional machine lathe, a laser beam is focused on a workpiece, and a material is removed by a laser beam irradiation effect at a focal point. Therefore, by selectively controlling the laser beam irradiation site on the workpiece, it is possible to remove the material at any site on the workpiece, and to mold not only the rotating body but also the solid body of any shape. By controlling the intensity of the laser beam, it is possible to precisely control the amount of the substance removed by the removal of the substance by the irradiation effect of the laser beam, so that a minute three-dimensional shape can be formed. Will be able to do it.

Therefore, according to the present invention, it is possible to form a minute solid having any desired shape from the material without limiting the material to be processed.

[Brief description of the drawings]

FIG. 1 is a schematic structural explanatory view of a laser processing apparatus according to a first embodiment for performing a laser processing method according to the first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a processing surface when a triangular pyramid is formed on a rectangular workpiece.

3A and 3B show a state in which a triangular pyramid is formed on a rectangular parallelepiped workpiece, where FIG. 3A is a top view and FIG. 3B is a front view.

FIG. 4 is a top view showing the progress of laser processing;
(A) shows a state processed to the processed surface 2, (b) shows a state processed to the processed surface 3, and (c) shows a state processed to the final processed surface n.

FIG. 5 is an enlarged explanatory view showing a surface state of a processing surface.

FIG. 6 is a schematic structural explanatory view of a laser processing apparatus according to a second embodiment for performing the laser processing method according to the second embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a relationship between a cylindrical workpiece and a triangular prism formed from the workpiece.

FIG. 8 is an explanatory diagram showing a processing surface when a triangular prism is formed from a cylindrical workpiece.

9A and 9B show a relationship between a light amount of a processing laser beam and a rotation angle of a workpiece by a rotating device. FIG. 9A shows a case where a processing surface 2 is formed, and FIG. 9B shows a case where a processing surface 3 is formed. Is shown.

FIG. 10 is an explanatory view of a main part for describing a horizontal irradiation method.

FIG. 11 is an explanatory view of a main part for describing a vertical irradiation method.

[Explanation of symbols]

10, 100, 200, 304, 404 Workpiece 12, 44 Vertical movement stage 14 Base 16 Laser beam 18, 18a, 18b Laser irradiation system 20 Processing laser 22 Light intensity controller 24 Correction optical system device 26 Surface shape measurement device Reference Signs List 28 control device 30 semi-transmissive mirror 32 total reflection mirror 34 movable mirror pair 36 total reflection mirror 40 rotating device 42 horizontal movement stage 102 triangular pyramid 202 triangular prism 200a, 200b end face 300 lens having relatively long focal length 302 processing laser light Outer edge 400 Lens with relatively short focal length 402 Irradiation position

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location B23K 26/06 A 26/08 H

Claims (18)

[Claims] 1. A laser beam for processing, which removes a substance on the surface by irradiating the surface of the workpiece, is condensed on the surface of the workpiece using a condensing optical system. A point is scanned on the surface of the workpiece and gradually moved inward from the surface of the workpiece in a stepwise manner.Only a substance at a desired portion from the workpiece surface is controlled in intensity of the processing laser light. A laser processing method, wherein the workpiece is removed by a substance removing action by irradiating the processing laser light to form the workpiece into a desired three-dimensional shape. 2. A laser beam for processing, which removes a substance on the surface by irradiating the surface of the workpiece, is condensed on the surface of the workpiece using a condensing optical system, and the rotation of the workpiece and the surface of the workpiece. Due to the relative movement of the processing laser light and the workpiece converged on the workpiece, the focal point of the processing laser light is scanned on the surface of the workpiece and inward from the surface of the workpiece. And sequentially removing the substance at a desired portion from the surface of the workpiece by removing the substance by the irradiation of the processing laser light while controlling the intensity of the processing laser light. A laser processing method characterized in that a is formed into a desired three-dimensional shape. 3. A laser beam for measurement for measuring the shape of the surface of the workpiece is focused on the surface of the workpiece using a first focusing optical system, and the material on the surface is irradiated by irradiating the surface of the workpiece. A processing laser beam for removing light is focused on the surface of the workpiece using a second focusing optical system, and a first focusing point on the surface of the workpiece due to focusing by the first focusing optical system. And scanning the second condensing point on the surface of the workpiece by the condensing of the second condensing optical system on the surface of the workpiece, and sequentially moving the second condensing point inward from the surface of the workpiece. According to the surface shape of the workpiece measured based on the measurement laser light, only the material at a desired portion from the workpiece surface is irradiated with the processing laser light while controlling the intensity of the processing laser light. And remove the workpiece by the desired standing action. A laser processing method characterized by forming into a body shape. 4. A laser light for measurement for measuring a shape of a surface of a workpiece and a laser light for processing for removing a substance on the surface by irradiating the surface of the workpiece with the same condensing optical system. Converging light on the surface of the workpiece, converging the light on the surface of the workpiece by the condensing, scanning the surface of the workpiece, and sequentially moving in a stepwise direction from the surface of the workpiece to the inside; According to the surface shape of the workpiece measured based on light, only the material at a desired site from the workpiece surface is controlled by controlling the intensity of the processing laser light while removing the substance by the irradiation of the processing laser light. A laser processing method comprising removing the workpiece and forming the workpiece into a desired three-dimensional shape. 5. A laser beam for measurement for measuring a shape of a surface of a workpiece is focused on the surface of the workpiece using a first focusing optical system, and a material on the surface is irradiated by irradiating the surface of the workpiece. A processing laser beam for removing light is focused on the surface of the workpiece using a second focusing optical system, and the rotation of the workpiece and focusing on the surface of the workpiece by the first focusing optical system By the relative movement of the measurement laser light and the workpiece to be scanned, while scanning the focal point of the measurement laser light and sequentially moving stepwise inward from the surface of the workpiece, Rotation of the workpiece,
By scanning the focal point of the processing laser light by the relative movement of the processing laser light and the workpiece focused on the workpiece surface by the second focusing optical system, According to the surface shape of the workpiece measured based on the measurement laser light while moving the workpiece in a stepwise manner from the surface of the workpiece sequentially, only a material at a desired portion from the workpiece surface is used for the processing. A laser processing method, wherein the laser beam is removed by a substance removing action by irradiating the laser beam for processing while controlling the intensity of the laser beam, and the workpiece is formed into a desired three-dimensional shape. 6. A laser beam for measurement for measuring a shape of a surface of a workpiece and a laser beam for processing for removing a substance on the surface by irradiating the surface of the workpiece with the same condensing optical system. The measurement is performed by focusing the light on the surface of the workpiece, rotating the workpiece, and moving the laser beam for measurement and the laser beam for processing and the workpiece relative to each other on the surface of the workpiece. The surface shape of the workpiece measured based on the measurement laser light while scanning the laser light and the focal point of the processing laser light while sequentially moving inward from the surface of the workpiece. According to the above, only a material at a desired portion from the surface of the workpiece is removed by a substance removing action by irradiation of the processing laser light while controlling the intensity of the processing laser light, and the workpiece is removed to a desired three-dimensional shape. Laser processing method characterized by forming the Jo. 7. The control of the intensity of the processing laser light,
Claims 1 and 2 wherein the operation is performed by operating / stopping laser oscillation.
The laser processing method according to any one of 3, 4, 5, and 6. 8. A laser beam for processing, which removes a substance on the surface by irradiating the surface of the workpiece, is condensed using a condensing optical system having a relatively long focal length, and the laser beam near the focal point of the laser beam for processing is condensed. The outer edge of the processing laser light is brought into contact with the surface of the workpiece, and the contact position caused by the contact is scanned on the surface of the workpiece and moved stepwise sequentially from the surface of the workpiece inward. A laser processing method comprising: removing only a substance on a surface of the workpiece with which the outer edge of the laser light contacts, by a substance removing action by irradiating the processing laser light to form a reference surface on the workpiece surface. . 9. The processing laser beam for condensing a processing laser beam for removing a substance on the surface of the workpiece by irradiating the surface of the workpiece with a condensing optical system having a relatively long focal length. The outer edge of the processing laser light near the focal point of the light is brought into contact with the surface of the workpiece, and the contact position due to the contact is scanned stepwise on the surface of the workpiece and sequentially inward from the surface of the workpiece in a stepwise manner. Moving, removing only the material on the surface of the workpiece contacted with the outer edge of the processing laser light by a substance removing action by irradiation of the processing laser light, and forming a reference surface on the workpiece surface in advance. Any one of item 1, 2, 3, 4, 5, 6 or 7
The laser processing method according to the item. 10. A laser beam for processing which removes a substance on the surface by irradiating the surface of the workpiece with a condensing optical system having a relatively short focal length, and the optical axis of the laser beam for processing is adjusted to the surface of the workpiece. The irradiation position where the intensity of the processing laser light is high on the focal point of the processing laser light is brought into contact with the surface of the workpiece, and the contact position by the contact is While scanning on the surface of the workpiece, the workpiece is moved in a stepwise manner inward from the surface of the workpiece, and only the material on the surface of the workpiece that is contacted with the irradiation position of the processing laser light is irradiated with the laser light for the processing. A laser processing method, characterized in that a reference surface is formed on the surface of the workpiece by removing by a substance removing action by irradiation. 11. The processing object, wherein a laser beam for processing, which removes a material on the surface of the workpiece by irradiating the surface of the processing object, is condensed with a light of the processing laser beam using a focusing optical system having a relatively short focal length. Focusing so that the axis is perpendicular to the surface of the workpiece, contacting the irradiation position where the intensity of the processing laser light on the focal point of the processing laser light is high with the surface of the workpiece, The contact position is scanned on the surface of the workpiece and sequentially moved inward from the surface of the workpiece in a stepwise manner, and only the material on the surface of the workpiece that the irradiation position of the processing laser light contacts is removed. A reference surface is formed in advance on the surface of the workpiece by removing by a substance removing action by irradiation of the processing laser beam,
The laser processing method according to any one of 2, 3, 4, 5, 6, and 7. 12. A processing laser for emitting a processing laser beam for removing a substance on the surface by irradiating the surface of the workpiece, a condensing optical system for condensing the processing laser beam on the surface of the workpiece, Scanning means for scanning a condensed point on the surface of the workpiece by the condensing optical system on the surface of the workpiece, and the collection of the surface of the workpiece in a stepwise manner inward from the surface of the workpiece. Moving means for moving a light spot; and, with the scanning and moving of the focal point by the scanning means and the moving means, removing only a substance at a desired portion from the surface of the workpiece by irradiating the processing laser light. And a control means for controlling the intensity of the processing laser light. 13. A processing laser for emitting a processing laser beam for removing a substance on the surface by irradiating the surface of the workpiece, and the processing laser beam emitted from the processing laser is collected on the surface of the workpiece. A condensing optical system that emits light, the rotation of the workpiece, and the relative movement between the processing laser light and the workpiece focused on the surface of the workpiece,
Scanning means for scanning the focal point of the processing laser light on the surface of the workpiece, moving means for sequentially moving the focal point of the workpiece surface inward from the surface of the workpiece, Along with the scanning and movement of the focal point by the scanning unit and the moving unit, the processing is performed such that only a material at a desired site is removed from the surface of the workpiece by a material removing action by irradiation of the processing laser light. And a control means for controlling the intensity of the laser light for use. 14. A measuring laser for emitting a measuring laser beam for measuring a shape of a workpiece surface, and a processing laser for emitting a processing laser beam for removing a surface material by irradiating the workpiece surface. A laser, a first condensing optical system that condenses the measurement laser light emitted from the measurement laser on the surface of the workpiece, and the processing laser light emitted from the processing laser to the workpiece. A second condensing optical system for condensing light on a surface, and scanning the first condensing point on the surface of the workpiece by the condensing of the first condensing optical system on the surface of the workpiece;
Scanning means for scanning a second condensing point on the workpiece surface by the condensing of the second condensing optical system on the workpiece surface; and Moving means for moving the first and second light converging points on the workpiece surface; and moving the first and second light condensing points by the scanning means and the moving means. Along with scanning and movement, according to the surface shape of the workpiece measured based on the measurement laser light, only a substance at a desired site is removed from the workpiece surface by a substance removing action by irradiation of the processing laser light. And a control means for controlling the intensity of the processing laser light. 15. A measuring laser for emitting a measuring laser beam for measuring a shape of a workpiece surface, and a processing laser for emitting a processing laser beam for removing a material on the surface by irradiating the surface of the workpiece. A laser, a condensing optical system that condenses the measuring laser light emitted from the measuring laser and the processing laser light emitted from the processing laser on the surface of the workpiece, and the condensing optical system. Scanning means for scanning a focal point on the workpiece surface by the focusing on the workpiece surface; and moving the focal point on the workpiece surface in a stepwise manner inward from the surface of the workpiece. Moving means, and scanning and movement of the focal point by the scanning means and the moving means, according to the surface shape of the workpiece measured based on the measurement laser beam, the workpiece table Only material of a desired site to remove a material removing action by irradiation of the processing laser light from the laser processing apparatus characterized by a control means for controlling the intensity of the processing laser light. 16. A measuring laser for emitting a measuring laser beam for measuring a shape of a workpiece surface, and a processing laser for emitting a processing laser beam for removing a material on the surface by irradiating the surface of the workpiece. A laser, a first condensing optical system that condenses the measurement laser light emitted from the measurement laser on the surface of the workpiece, and the processing laser light emitted from the processing laser to the workpiece. A second condensing optical system for condensing light on a surface, a rotation of the workpiece, and the measurement laser light and the workpiece condensed on the surface of the workpiece by the first condensing optical system. By the relative movement, the focal point of the measurement laser beam is scanned on the surface of the workpiece, and the rotation of the workpiece and the light that is focused on the surface of the workpiece by the second focusing optical system. With laser light for processing Scanning means for scanning the focal point of the processing laser light on the surface of the workpiece by relative movement with respect to the workpiece; and Moving means for moving the converging point of the measuring laser light and the converging point of the processing laser light; and the condensing point of the measuring laser light and the collecting of the processing laser light by the scanning means and the moving means. With the scanning and movement of the light spot, according to the surface shape of the workpiece measured based on the laser beam for measurement, only the substance at a desired portion from the surface of the workpiece is irradiated with the laser beam for processing to remove the substance. Control means for controlling the intensity of the processing laser light so that the laser light is removed by the laser processing apparatus. 17. A measuring laser for emitting a measuring laser beam for measuring the shape of a workpiece surface, and a processing laser for emitting a processing laser beam for removing a surface material by irradiating the surface of the workpiece. A laser, a condensing optical system that condenses the laser beam for measurement emitted from the laser for measurement and the laser beam for processing emitted from the laser for machining on the surface of the workpiece, and rotation of the workpiece. And, by the relative movement of the measurement laser light and the processing laser light and the processing light condensed on the workpiece surface, the converging point of the measurement laser light and the processing laser light is Scanning means for scanning on the surface of the workpiece; and moving the focal point of the measurement laser light and the processing laser light on the surface of the workpiece in a stepwise manner inward from the surface of the workpiece. Moving means, and the scanning and moving of the focal point of the measuring laser light and the processing laser light by the scanning means and the moving means, and the surface of the workpiece measured based on the measuring laser light. Control means for controlling the intensity of the processing laser light so as to remove only a material at a desired site from the surface of the workpiece by a material removing action by irradiation of the processing laser light according to the shape. And laser processing equipment. 18. The apparatus according to claim 12, wherein the moving means moves the workpiece in an optical axis direction of the processing laser light.
The laser processing apparatus according to any one of 3, 14, 15, 16 or 17.