JP2001001177A - Method for laser beam machining and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for laser beam machining and a device therefor capable of improving velocity of processing a work. SOLUTION: By making nearly parallel laser beams 21a pass through a cylindrical lens 19, a laser beam 21b having a long and narrow transverse section is generated, and thus generated laser beam 21b is projected on a work 6, and at the same time a spot S of the laser beam 21b on the work 6 is moved in the direction of working 22 so that the longitudinal direction of the spot S may coinside with the direction of working.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a laser processing method and a laser processing apparatus.

[0002]

2. Description of the Related Art By irradiating a work with a laser,
2. Description of the Related Art Laser processing methods for performing various types of processing on a work are known. In such a laser processing method, generally, a laser beam generated by a laser oscillator is converged by a convex lens to increase the energy density, and the laser beam having the increased energy density is irradiated on the work, thereby performing a required processing on the work. Has been given.

[0003]

By the way, in the above-mentioned conventional laser processing method, the shape of a portion irradiated with a laser beam (hereinafter, referred to as a spot) on a work is usually set to a circle. The shape of this spot is mainly set as such due to the limitation of the laser oscillator that generates the laser, and is not set from the viewpoint of improving the processing speed of the work, and therefore, is not necessarily the optimum one. Absent.

The present invention has been made in view of the above problems, and has as its object to provide a laser processing method and a laser processing apparatus capable of improving the processing speed of a work.

[0005]

In order to solve the above-mentioned problems, a laser processing method and a laser processing apparatus according to the present invention provide a laser having an elongated cross section by passing a substantially parallel laser beam through a cylindrical lens. A beam is generated, and the generated laser beam is irradiated on the workpiece, and the irradiated part of the laser beam on the workpiece is moved in the processing direction such that the longitudinal direction of the irradiated part matches the processing direction. Then, the work is processed (claims 1 and 4). With this configuration, the processing speed of the work can be improved. In addition, since a cylindrical lens is used, a laser beam having a desired cross-sectional shape can be easily generated.

Further, the laser processing method and the laser processing apparatus according to the present invention have an elongated cross section by passing a substantially parallel laser beam through a convex lens arranged obliquely to the optical axis of the substantially parallel laser beam. A laser beam is generated, and the generated laser beam is irradiated on the work, and the irradiated portion of the laser beam on the work is arranged such that the longitudinal direction of the irradiated portion matches the processing direction,
The workpiece is machined by moving the workpiece in the machining direction (claims 2 and 5). Even with such a configuration, the processing speed of the work can be improved. In addition, since a normal convex lens is used, the configuration is simplified.

Further, the laser processing method and the laser processing apparatus according to the present invention are such that a substantially parallel laser beam is sequentially passed through a cylindrical lens and a convex lens.
A laser beam having an elongated cross section whose energy density at the center is higher than that of the other portions is generated, and the generated laser beam is irradiated on the work, and the irradiated portion of the laser beam on the work is irradiated with the laser beam. The workpiece is machined by moving the portion in the machining direction such that the longitudinal direction of the portion coincides with the machining direction (claims 3 and 6). With this configuration, in the portion of the workpiece irradiated with the laser beam, preheating is performed in the front portion in the processing direction, processing is performed in the center portion, and cooling is performed in the rear portion. Therefore, processing becomes easy. In addition, since the cylindrical lens and the convex lens are used in combination, a laser beam having a desired cross-sectional shape and an energy density distribution in the cross-section can be easily generated.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a schematic configuration of a laser processing apparatus according to an embodiment of the present invention, FIG. 2 is a right side view thereof, and FIG. 3 is a rear view thereof. In these figures, the furnace is shown in cross section at the center.

In these figures, a laser processing apparatus 1
Has a furnace 2 and a laser irradiation device 7. Furnace 2
Here, it consists of a rectangular parallelepiped housing, and on the front and back,
Openings 2a, 2b and doors 4, 5 for opening and closing the openings 2a, 2b are provided, respectively. The front opening 2a and the door 4 allow the work 6 to enter and leave the work, and the rear opening 2b and the door 5 allow the work 6 to be irradiated with a laser beam. Inside the furnace 2, a horizontal turntable 3 for mounting a workpiece 6 is disposed so as to be rotatable around a vertical axis (Z axis) and to be movable in a horizontal X-axis direction. ing.

The laser irradiation device 7 has a laser oscillator (not shown) and a frame 8. The frame body 8 is formed in a gate shape, and is erected behind the furnace 2 so that the upper side frame 8a faces the Y-axis direction of the horizontal plane. A sliding body 20 movable along the upper side frame 8a (in the Y-axis direction) is provided on the upper side frame 8a.
Are arranged. A cylindrical elevating body 10 extending in the Z-axis direction is attached to the sliding body 20 so as to be movable (elevated) in the direction of its central axis 10a. At the bottom of the lifting body 10,
A cylindrical first revolving body 11 is protruded in the X-axis direction so as to be rotatable around a central axis 12 thereof. First revolving superstructure
A cylindrical second revolving body 14 is provided at a tip of the first revolving body 11 in a direction perpendicular to the center axis 12 of the first revolving body 11 so as to be rotatable around a center axis 13 thereof. I have. A hollow frusto-conical processing head 15 is provided on the peripheral surface of the second revolving unit 14 in a direction perpendicular to the center axis 14 of the second revolving unit 14. A reflecting plate 16 for protecting the first and second revolving units 11 and 14 from the laser beam reflected by the work 6 is provided at the base of the processing head 15.
Are arranged. The turntable 3, the sliding body 20, the elevating body 10, the first slewing body 11, and the second slewing body 14 are each driven by a drive motor (not shown), and the drive motor is controlled by a control device (not shown). Thus, the processing head 15 can move relative to the work 6 in the three-dimensional direction, and can change the direction freely within a predetermined angle range.

Further, one end of an extendable guide cylinder 9 having the other end connected to the output end of the laser oscillator is connected to the sliding body 20. The guide cylinder 9 communicates with the processing head 15 via the internal space of the sliding body 20, the elevating body 10, the first rotating body 11, and the second rotating body 14. In addition, the guide cylinder 9, the sliding body
20 and the elevating body 10 are connected to the center axis 9a of the guide cylinder 9 and the elevating body 10
And a central axis 10a of the sliding member 20 are arranged to be orthogonal to each other. Further, the lifting and lowering body 10 and the first revolving bodies 11, the first revolving body 11 and the second revolving bodies 14, and the second revolving body 14 and the processing head 15 are mutually central axes (10 a and 10 a). 12, 12 and 13, 13 and 18) are arranged orthogonally. At the intersection of these central axes, a reflection mirror 17 is arranged so as to form an angle of 45 degrees with both central axes. In addition, a condensing lens 19 is provided on the center axis 18 of the processing head 15 before the processing head 15. As a result, the laser beam generated by the laser oscillator
21 includes a guide cylinder 9, a lifting / lowering body 10, a first revolving body 11, and a second
The laser beam travels along the central axis of the revolving body 14 and the processing head 15, is converged by the condenser lens 19, and is emitted from the tip of the processing head 15.

Next, the condenser lens 19 will be described in detail. 4A and 4B are schematic diagrams showing the relationship between the condensing lens 19 and the spot on the work, wherein FIG. 4A is a diagram viewed from the oblique front of the work surface of the work, and FIG. FIG. 3C is a diagram viewed from a direction, FIG. 4C is a diagram viewed from a processing direction, and FIG. In the drawing, the processing head and the second rotating body are omitted.

As shown in the figure, the condenser lens 19 here is constituted by a cylindrical lens. The cylindrical lens 19 has one main surface formed to be flat, and the other main surface formed to be a part of a peripheral surface of a cylinder.
That is, the other main surface is a central axis (hereinafter, referred to as a vertical section) of the cylindrical lens 19 (a section parallel to the optical axis 101).
It is formed so as to be curved at a constant curvature in a direction perpendicular to the extension axis 102. The cylindrical lens 19 is disposed such that its optical axis 101 coincides with the central axis 18 of the processing head 15 (see FIG. 2).

Next, the operation (laser processing method) of the laser processing apparatus configured as described above will be described with reference to FIGS.

In these figures, in order to perform laser processing on the work 6, first, a processing method (processing direction, processing conditions, etc.) for the work 6 is set in advance. At this time, as shown in FIG. 4A, the longitudinal direction of the spot S is set so as to always coincide with the processing direction (direction of relative movement of the processing head 15 with respect to the workpiece 6) 22. In other words, it is set so that the extending axis 102 of the cylindrical lens 19 and the processing direction 22 are always on the same plane. Then, the door 4 on the front of the furnace 2
Is opened, the work 6 is placed on the turntable 3, and the door 4 is closed. Next, the door 5 on the rear surface of the furnace 2 is opened, and the laser processing apparatus 1 is started. Then, the work 6 and the processing head
15 are relatively moved in a preset direction, and a laser beam 21 is irradiated toward the workpiece 6 from the tip of the processing head 15. Thereby, the spot S moves on the workpiece 6 in the processing direction 22, and the laser processing set as described above is performed on the workpiece 6. At this time, the direction of the processing head 15 is changed so that the first rotating body 11 and the second rotating body 14 rotate, and the extending axis 102 of the cylindrical lens 19 and the processing direction 22 are always in the same plane. Controlled.

Here, the laser beam 21 for the workpiece 6 is
Will be described in detail. As shown in FIG.
Circular cross section from laser oscillator (cross section perpendicular to optical axis)
Is emitted, and this enters the cylindrical lens 19. Then, as shown in FIGS. 4B and 4C, the incident substantially parallel beam 21a is not converged in the direction of the extension axis 102 of the cylindrical lens 19, but is
Is converged only in a direction perpendicular to the direction, and becomes a convergent beam 21b having an elongated cross section in the direction of the extension axis 102. Accordingly, the spot S of the convergent beam 21b on the workpiece 6 has an elongated shape in the extending axial direction 102, that is, the processing direction 22.
Thereby, the processing speed of the work 6 is improved.

Next, a modified example of this embodiment will be described.

FIGS. 5A and 5B are schematic views showing another configuration example of the condenser lens, wherein FIG. 5A is a view seen from a direction perpendicular to the processing direction, and FIG. 5B is a view perpendicular to the processing surface of the workpiece. It is the figure seen from the direction. In the drawing, the processing head and the second rotating body are omitted.

As shown in the figure, here, the condenser lens 19
Is composed of a normal circular convex lens, the convex lens 19,
It is disposed obliquely with respect to the optical axis 18 (here, the center axis of the processing head) of the substantially parallel beam 21a from the laser oscillator.
With such a configuration, the degree of convergence of the substantially parallel beam 21a incident on the convex lens 19 in the inclination direction of the convex lens 19 becomes small, so that a convergent beam 21b having an elongated cross section in the inclination direction is obtained. Accordingly, the spot S of the convergent beam 21b on the workpiece 6 also has a shape elongated in the direction of inclination of the convex lens 19. Therefore, at the time of laser processing of the work 6, the processing head is set so that the longitudinal direction of the spot S always coincides with the processing direction 22, in other words, the inclination direction of the convex lens 19 and the processing direction are always in the same plane. Is relatively moved with respect to the work 6, the processing speed of the work 6 can be improved.

FIGS. 6A and 6B are schematic views showing still another configuration example of the condenser lens. FIG. 6A is a lower perspective view of the condenser lens, and FIG. 6B is a view seen from a direction perpendicular to the processing direction. , (C) is a diagram viewed from the processing direction, (d) is a diagram viewed from a direction perpendicular to the processing surface of the workpiece, and (e) is a diagram schematically illustrating an energy density distribution of the spot on the workpiece in the processing direction. It is. In the drawing, the processing head and the second rotating body are omitted.

As shown, the condenser lens 19 includes a cylindrical lens (hereinafter, referred to as a cylindrical lens portion) 19a and a circular convex lens (hereinafter, referred to as a convex lens portion) 19b having a smaller diameter than the cylindrical lens portion 19a.
It is composed of a compound lens in which both optical axes 101 and 103 coincide and are formed so that their flat main surfaces are in contact with each other. The cylindrical lens portion 19a and the convex lens portion 19b may be integrated or separate. This compound lens 19 has its optical axes 101 and 103
(See FIG. 2).

In such a configuration, the processing head is relatively moved with respect to the workpiece 6 so that the extending direction of the cylindrical lens portion 19a of the compound lens 19 and the processing direction are in the same plane, and the laser processing of the workpiece 6 is performed. Do it, compound lens
The substantially parallel beam 21a that has entered the cylindrical lens portion 19a of FIG. 19 becomes a convergent beam 21b having an elongated cross section in the direction of the extending axis 102 of the cylindrical lens portion 19a, and further, the central portion of the convergent beam 21b is a convex lens portion 19b. (21c), and the light intensity increases. And
The convergent beam 21b is applied to the work 6, and as shown in (d), a spot S which is elongated in the processing direction 22 and has a portion S0 having a large light intensity at the center thereof is generated. In the energy density distribution of the spot S in the processing direction 22, the energy density of the central portion R1 of the spot S is larger than the energy density of the portion R2 before and after the central portion R1 as shown in FIG. Therefore, preheating is performed in a front portion of the spot S in the processing direction 22, processing is performed in a central portion thereof, and cooling is performed in a rear portion thereof. For this reason, machining is facilitated, and it is particularly suitable when a plurality of workpieces are fused.

In the above description, in the compound lens 19, the cylindrical lens portion 19a and the convex lens portion 19b are arranged adjacent to each other, but they may be arranged separately.

Although the cross section of the laser beam 21 is rounded, it may be square.

Although the laser beam 21 is irradiated at right angles to the processing surface of the workpiece 6, the laser beam 21 may be irradiated at an angle before and after the processing direction.

[0027]

The present invention is embodied in the form described above, and has the following effects. (1) When laser processing is performed using a laser beam having an elongated cross section, the processing speed of a workpiece can be improved. In addition, when a cylindrical lens is used to generate a laser beam having the elongated cross section, a laser beam having a desired cross sectional shape can be easily generated. Thus, the configuration can be simplified. (2) When laser processing is performed using a laser beam having a narrow cross section in which the energy density of the central portion is higher than that of other portions, the processing is facilitated. Further, a laser beam having a desired cross-sectional shape and energy density distribution in the cross-section can be easily generated.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of a laser processing apparatus according to an embodiment of the present invention.

FIG. 2 is a right side view showing a schematic configuration of the laser processing apparatus according to the embodiment of the present invention.

FIG. 3 is a rear view showing a schematic configuration of the laser processing apparatus according to the embodiment of the present invention.

FIG. 4 is a schematic diagram showing a relationship between a condenser lens and a spot on a work, and is a diagram (a) viewed obliquely from the processing surface of the work, and a diagram viewed from a direction perpendicular to the processing direction ( b), a view (c) as viewed from the processing direction, and (d) as viewed from a direction perpendicular to the processing surface of the work.

FIGS. 5A and 5B are schematic diagrams illustrating another configuration example of the condenser lens, as viewed from a direction perpendicular to a processing direction (a) and a view from a direction perpendicular to a processing surface of a workpiece (b). It is.

FIG. 6 is a schematic view showing still another example of the configuration of the condenser lens, in which a lower perspective view of the condenser lens (a), a view seen from a direction perpendicular to the processing direction (b), and a view from the processing direction. FIG. 5C is a diagram (c), a diagram (d) as viewed from a direction perpendicular to the work surface of the work, and a diagram (e) schematically showing the energy density distribution of the spot on the work in the work direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser processing apparatus 2 Furnace 2a, 2b opening 3 Turntable 4,5 Door 6 Work 7 Laser irradiation apparatus 8 Frame 8a Upper side frame 9 Guide cylinder 9a Center axis 10 Elevating body 10a Center axis 11 First revolving body 12 Center axis 13 Central axis 14 Second revolving unit 15 Processing head 16 Reflector 17 Reflector mirror 18 Central axis 19 Condensing lens 19a Cylindrical lens unit 19b Convex lens unit 20 Sliding body 21 Laser beam 21a Substantially parallel laser beam 21b Convergent beam 22 Processing direction 101 Optical axis 102 Extension axis 103 Optical axis S Spot S0 Central part R1 Central part R2 Front and rear parts

Claims (6)

[Claims] A laser beam having an elongated cross section is generated by passing a substantially parallel laser beam through a cylindrical lens, and the generated laser beam is irradiated on a workpiece.
A laser processing method for processing the work by moving an irradiation part of the laser beam on the work in the processing direction such that a longitudinal direction of the irradiation part coincides with the processing direction. 2. A laser beam having an elongated cross section is generated by passing a substantially parallel laser beam through a convex lens arranged obliquely with respect to the optical axis of the substantially parallel laser beam. And irradiate
A laser processing method for processing the work by moving an irradiation part of the laser beam on the work in the processing direction such that a longitudinal direction of the irradiation part coincides with the processing direction. 3. A laser beam having an elongated cross section whose energy density at the center thereof is higher than that of other portions by passing a substantially parallel laser beam sequentially through a cylindrical lens and a convex lens. While irradiating the work with the laser beam,
A laser processing method for processing the work by moving an irradiation part of the laser beam on the work in the processing direction such that a longitudinal direction of the irradiation part coincides with the processing direction. 4. A means for generating a laser beam having an elongated cross section by passing a substantially parallel laser beam through a cylindrical lens; a means for irradiating the generated laser beam to a work; Means for moving the laser beam irradiation part in the processing direction such that the longitudinal direction of the irradiation part coincides with the processing direction. 5. A means for generating a laser beam having an elongated cross section by passing a substantially parallel laser beam through a convex lens arranged obliquely with respect to an optical axis of the substantially parallel laser beam, and the generated laser beam. A laser processing apparatus comprising: means for irradiating a laser beam onto a work; and means for moving an irradiated portion of the laser beam on the work in the processing direction such that a longitudinal direction of the irradiated part coincides with the processing direction. . 6. A means for generating a laser beam having an elongated cross section whose energy density at a central portion thereof is higher than that of other portions by sequentially passing a substantially parallel laser beam through a cylindrical lens and a convex lens; Means for irradiating the work with the generated laser beam; and means for moving an irradiation part of the laser beam on the work in the processing direction such that the longitudinal direction of the irradiation part coincides with the processing direction. Laser processing equipment.