JP2581574B2 - Laser processing method and apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing method and apparatus, and more particularly to stabilization of laser beam oscillation.

[Prior Art] FIG. 3 is a sectional view showing a conventional beam oscillating laser processing apparatus disclosed in Japanese Utility Model Publication No. 60-37182, for example. In FIG. 3, (2) is a laser beam emitted from a laser oscillator (not shown), and (6) is a laser beam (2).
A condensing optical system for condensing the laser beam, (20) a total reflection mirror for changing the direction of the converged laser beam (2), and (21) a laser beam reflected by the total reflection mirror (20) for the workpiece. (9) It is a total reflection mirror that irradiates upward. Either the total reflection mirror (20) or the total reflection mirror (21) is rotatable by a fixed angle, and the condensing optical system (6) and the two total reflection mirrors (20) and (2)
1) constitutes the processing head (22). (10) is a processing table on which the workpiece (9) is placed.

The operation of the laser processing apparatus configured as described above will be described. The laser beam (2) condensed by the condensing optical system (6) is reflected by a total reflection mirror (20) and a total reflection mirror (21) and is irradiated to a processing position of a workpiece (9). In this state, the total reflection mirror (2
The laser beam (2) irradiating the workpiece (9) can be oscillated by rotating either one of (0) and (21) by a fixed angle around an axis perpendicular to the drawing. The swing width of the laser beam (2) can be controlled by the rotation angle of the rotating total reflection mirror.

As described above, while oscillating the laser beam (2) irradiating the workpiece (9), the machining head (22) itself or the machining table (10) is perpendicular to the oscillation direction of the laser beam (2). By moving in the direction, it is possible to form a wide and uniform bead (23) as shown in FIG. 4 by wide and uniform processing, for example, welding, and to harden the uniform hardened layer having a wide width. Can be obtained.

[Problem to be Solved by the Invention] In the conventional laser processing apparatus configured as described above, since the laser beam (2) is scanned by rotating the total reflection mirror in one direction, the workpiece is processed. (9) The oscillating direction of the laser beam (2) oscillating above is limited to one direction. Therefore, when the swing direction of the laser beam (2) during processing is perpendicular to the moving direction of the processing head (22) or the processing table (10), a wide range of welding and quenching can be performed. When the swing direction of 2) is the same as the moving direction of the processing head (22) and the processing table (10), wide processing cannot be performed. For example, a narrow bead (24) as shown in FIG. However, there is a problem that it can only be formed.

In addition, there is also a problem that the processing width becomes non-uniform when processing a complicated shape.

The present invention has been made in order to solve such a problem, and a laser processing method and a laser processing method capable of performing a wide and uniform processing without any processing unevenness regardless of the moving direction of a processing head or a processing table. The purpose is to obtain.

[Means for Solving the Problems] In a laser processing method according to the present invention, a laser beam emitted from a laser oscillator is reflected by a first total reflection mirror rotating around an optical axis to change the direction, and The reflected laser beam is reflected by a second total reflection mirror rotating about the optical axis while being shifted from the optical axis of the laser beam focusing optics, and the laser beam is reflected on a workpiece placed on a processing table. The first rotation trajectory and the second rotation trajectory are formed in a superimposed manner.

In the laser processing apparatus according to the present invention, a direction changing system for changing the direction of the laser beam is provided in front of the focusing optical system, and the laser beam emitted from the laser oscillator and reflected by the total reflection mirror is provided in the direction changing system. A first total reflection mirror whose reflection surface is inclined to change the direction of the laser beam, and a reflection surface such that the direction of the laser beam reflected by the first total reflection mirror is shifted from the direction of the optical axis of the condensing optical system. In order to rotate the laser beam reflected by the tilted second total reflection mirror and the first and second total reflection mirrors around the optical axis of the condensing optical system, the first and second mirrors are synchronized with the driving device. And a rotating device for rotating the second total reflection mirror.

[Operation] In the present invention, a first total reflection mirror having a reflecting surface inclined to change the direction of a laser beam emitted from a laser oscillator provided in a direction conversion system and reflected by the total reflection mirror, The laser beam from the laser oscillator to the condensing optical system via a second total reflecting mirror whose reflecting surface is inclined so that the direction of the laser beam reflected by the total reflecting mirror is shifted from the direction of the optical axis of the condensing optical system When the first and second total reflection mirrors are rotated in this state, the laser beam incident on the condensing optical system rotates in accordance with the rotation of the first and second total reflection mirrors. I do. Then, the laser beam forms a first rotation trajectory and a second rotation trajectory in the first rotation trajectory on the workpiece disposed at the end of the condensing optical system, and is more dense and has no processing unevenness. Performs uniform processing with a wide and arbitrarily varied processing width.

FIG. 1 is a configuration diagram showing an embodiment of the present invention. First
In the figure, (1) is a laser oscillator for emitting a laser beam (2), and (3) is a total reflection mirror having a fixed reflecting surface for changing the direction of the laser beam (2) emitted from the laser oscillator (1). is there. (15) is a first total reflection mirror capable of tilting a reflection surface (15a) at an arbitrary angle in order to change the direction of the laser beam (2) reflected by the total reflection mirror (3), and (5) is The reflecting surface (5a) is inclined at an arbitrary angle so that the direction of the laser beam (2) reflected by the first total reflection mirror (15) is shifted from the direction of the optical axis (7) of the focusing optical system (6). A second total reflection mirror capable of reflecting the reflection surfaces (5a), (15
a) can be adjusted so that the laser beam (2) is guided to a position shifted from the central axis of the total reflection mirrors (5) and (15) facing each other.

(8) and (16) are the first and second total reflection mirrors (5) and (1).
A rotating device for rotating each of the mirrors 5) rotates the first and second total reflection mirrors (5) and (15) to rotate the laser beam (2) incident on the condensing optical system (6). . Further, a direction changing system for changing the direction of the laser beam (2) is constituted by the total reflection mirrors (3), (5), (15) and the rotating devices (8), (16). The processing head is constituted by the optical optical system (6).

(9) is a workpiece, (10) is a processing table on which the workpiece (9) is mounted, (11) is an X-axis drive motor for moving the processing table (10), (12) is a Y-axis drive motor, (13) is a drive device for driving the X-axis drive motor (11) and the Y-axis drive motor (12). The rotating devices (8) and (16) rotate the total reflection mirrors (5) and (15) in synchronization with the driving device (13).

The operation of the laser processing apparatus configured as described above will be described. A laser beam (2) emitted from a laser oscillator (1) is incident on a condensing optical system (6) via total reflection mirrors (3), (15) and (5). At this time, the laser beam (2) incident on the total reflection mirror (15) is emitted to a position off the center of the total reflection mirror (5), and the laser beam (2) incident on the total reflection mirror (5) is A laser beam (2) which is reflected on an axis shifted from the optical axis (7) of the condensing optical system (6) and becomes oblique rays enters the condensing optical system (6). in this way,
The oblique ray of the laser beam (2) is collected by the focusing optical system (6)
The laser beam (2) emitted from the condensing optical system (6) by being incident on the object is condensed on the workpiece (9) at a position shifted from the optical axis (7) of the condensing optical system (6). I do. X-axis drive motor (11) that moves the processing table (10) in this state
And the Y-axis drive motor (12) are driven by the drive device (13) in accordance with the processing shape to move the workpiece (9), and at the same time, are rotated from the drive device (13) to the rotation devices (8), (16). To rotate the total reflection mirrors (5) and (15) by driving the rotation devices (8) and (16). This total reflection mirror (5), (1
The laser beam (2) reflected by the total reflection mirrors (5) and (15) by the rotation of (5) rotates conically around the optical axis (7) of the condensing optical system (6). The trajectory (14) of the focal point of the laser beam (2) emitted from the system (6) on the workpiece (9) rotates around the optical axis (7).
Note that the processing width can be changed according to the rotation diameter.

Thus, the laser beam (2) on the workpiece (9)
As shown in FIG. 2 (a), the first rotation locus (size rotation locus) (14a) and the first rotation locus (14a)
In the second rotation locus (small rotation locus) (14
Form b). As a result, it is possible to perform a heat treatment that is more precise and has no processing unevenness than the processing obtained by rotating a single total reflection mirror (b in the same figure), and the width of the processing table (10) is not dependent on the moving direction. Wide uniform processing can be performed. Further, the swing width of the laser beam (2) on the workpiece (9) can be varied arbitrarily in a wide range, and a complicated shape can be processed.

The laser beam (2) reflected by the total reflection mirror (5)
The reflecting surfaces (5a), (15) of the total reflection mirrors (5), (15) are changed so as to change the angle θ between the optical axis (7) of the focusing optical system (6).
By changing the inclination of a), an arbitrarily changing processing width can be obtained, and an excellent laser processing apparatus can be obtained.

According to the laser processing method of the present invention, a laser beam emitted from a laser oscillator is reflected by a first total reflection mirror rotating about an optical axis to change the direction, and the reflected laser beam is reflected. Is reflected by the second total reflection mirror rotating about the optical axis while being shifted from the optical axis of the laser beam condensing optical system, and the first rotation of the laser beam is performed on the workpiece placed on the processing table. Since the trajectory and the second rotation trajectory are formed so as to overlap each other, it is possible to uniformly perform the heat treatment on the workpiece.

The laser processing apparatus according to the present invention further includes a first total reflection mirror having a reflecting surface inclined to change the direction of the laser beam emitted from the laser oscillator and reflected by the total reflection mirror, to the direction conversion system, A second total reflection mirror whose reflection surface is inclined so that the direction of the laser beam reflected by the first total reflection mirror is shifted from the direction of the optical axis of the condensing optical system, and reflection by the first and second total reflection mirrors A rotating device for rotating the first and second total reflection mirrors in synchronization with a driving device for rotating the laser beam about the optical axis of the condensing optical system; Irrespective of the moving direction of the working table or working head, uniform working with a wide working width can be performed densely without uneven heating, and the above-described laser processing method can be realized.

Further, the swing width and the like can be varied arbitrarily in a wide range, and an excellent laser processing apparatus capable of performing finer processing even in a complicated shape or the like can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIGS. 2 (a) and 2 (b) are explanatory diagrams of the operation of the embodiment of the present invention, and FIG.
FIG. 4 is a cross-sectional view showing a conventional beam swing laser processing apparatus, FIG. 4 is a cross-sectional view showing a wide bead, and FIG. 5 is a cross-sectional view showing a narrow bead. In the figure, (1) is a laser oscillator, (2) is a laser beam, (3), (5), and (15) are total reflection mirrors, (6) is a focusing optical system, (7) is an optical axis, 8) and (16) are rotating devices,
(9) is a workpiece, (10) is a processing table, (13) is a driving device, and (14) is a locus of a laser beam focusing point.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-292122 (JP, A) Jikken Sho 59-22946 (JP, Y2) WO 87/5843 (WO, A)

Claims (2)

(57) [Claims] A laser beam emitted from a laser oscillator is reflected by a first total reflection mirror rotating about an optical axis to change the direction, and the reflected laser beam is rotated about an optical axis. The laser beam is reflected off the optical axis of the condensing optical system by the total reflection mirror of No. 2 and the first rotation trajectory and the second rotation trajectory of the laser beam are superimposed on the workpiece placed on the processing table. A laser processing method characterized by being formed by forming. 2. A laser oscillator for generating a laser beam, a direction changing system having a plurality of total reflection mirrors for changing a traveling direction of a laser beam emitted from the laser oscillator, and having a direction changed by the direction changing system. A processing head comprising a condensing optical system for condensing a laser beam, a processing table on which a workpiece to be processed by the laser beam condensed by the processing head is mounted, and a processing head or a processing table formed into a processing shape. Therefore, in a laser processing apparatus having a moving drive device, the first direction conversion system is provided with a first full-face in which a reflecting surface is inclined to change a direction of a laser beam emitted from the laser oscillator and reflected by the total reflection mirror. A reflecting mirror, a second total reflecting mirror having a reflecting surface inclined such that the direction of the laser beam reflected by the first total reflecting mirror is shifted from the direction of the optical axis of the light-collecting optical system; A rotating device that rotates the first and second total reflection mirrors in synchronization with the driving device to rotate the laser beam reflected by the second total reflection mirror around the optical axis of the focusing optical system; A laser processing apparatus comprising: