JPH06344170A - Laser beam machining device - Google Patents

Abstract

PURPOSE:To transmit laser beam in the optical fiber placed opposite each other in time sharing to a machining point so as to enable multi-point machining by rotating and slide moving on the optical axis the optical system inserted between the integrated laser oscillator consisting of a bend mirror/beam collective lens and optical fiber. CONSTITUTION:After the laser beam 7 emitted from a laser oscillator 1 is collected through a bend mirror 2 and collective lens 3, the converged beam spot is made incident on the end face of an optical fiber 4. When the integrated optical system consisting of a bend mirror 2 and collective lens 3 is rotated around the optical axis O, the converged beam point scans so as to move peripherally around the rotating center, switching in sequence by time sharing method and being made incidence on each optical fiber 4 dispersedly arranged on the scanning locus. In the case of the arrangement that many optical fibers is placed in short pitch interval, the laser beam is smoothly subjected to time sharing, being made incidence on the optical fiber 4 to be transmitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus for performing multi-point processing by transmitting laser light emitted from a laser oscillator to a plurality of optical fibers in a time-sequential manner in a time division manner.

[0002]

2. Description of the Related Art As a laser processing method for cutting, welding, soldering, etc. using a YAG laser, for example, a method of directly irradiating a processing point of a workpiece with a laser beam emitted from a laser oscillator through a condenser lens, or a laser beam After transmitting to the processing point of the work through the optical fiber,
Further, there is a method in which laser light emitted from an optical fiber is condensed by a condenser lens to perform processing.

Particularly in the latter method of transmitting laser light using an optical fiber, it is possible to construct a flexible laser processing system capable of multi-point processing by distributing laser light to a plurality of optical fibers for transmission. it can. Further, as a multi-point processing method using a plurality of optical fibers, a laser beam emitted from a laser oscillator is energy-divided and simultaneously distributed to a plurality of optical fibers, or a laser beam is time-divided into a plurality of optical fibers. There is a method of distributing to a fiber and transmitting in time series. Among the various transmission methods described above, the present invention is particularly a multi-point processing in which laser light is time-divided and time-sequentially transmitted to a plurality of optical fibers. System laser processing apparatus.

Next, FIGS. 4 and 5 show a conventional example of a laser processing apparatus using the above-mentioned time division transmission system. First,
In FIG. 4, a YAG laser oscillator 1 has an output side provided with a bend mirror 2 for scanning that moves in the direction of arrow P along the optical axis O, and reflects the laser light along the movement path of the bend mirror 2. A plurality of optical fibers 4 combined in a one-to-one relationship with the condenser lens 3 are arranged on the side. A condenser lens 5 is combined with the other end of each optical fiber 4, and the laser light transmitted through the optical fiber 4 passes through the condenser lens 5 and is condensed. The focused spot irradiates the processing point of the work (workpiece) 6 and is used for processing.

By operating the scanning bend mirror 2 to reciprocate along the optical axis O in the direction of arrow P, the incidence of the laser light 7 emitted from the laser oscillator 1 on each optical fiber 4 is sequentially switched, As a result, the laser light 7 is time-sequentially transmitted and irradiated to the work processing point through each optical fiber 4 to perform multipoint processing. On the other hand, FIG.
In this device, the condenser lens 3 is provided on the output side of the laser oscillator 1 and the bend mirror 2 for rotational scanning arranged in the subsequent stage (the mirror is moved in the direction of the arrow Q by driving a galvanometer around a rotation axis perpendicular to the plane of the drawing). The optical fiber 4 is a condensing lens 3
The end faces are aligned with the focal point of the and are dispersed and arranged on the movement locus of the focused spots accompanying the rotation of the bend mirror 2.

With such a structure, when the bend mirror 2 is rotated in the direction of the arrow Q, the laser light 7 emitted from the laser oscillator 1 passes through the condenser lens 3 and the bend mirror 2 and is time-divided on the end face of each optical fiber 4. The light enters and is transmitted through the optical fiber 4 in time series to the processing point of the work.

[0007]

The conventional time division transmission system described above has the following drawbacks. First, in the method of FIG. 4, as the number of the optical fibers 4 increases, the moving distance of the bend mirror 2 becomes longer, the switching time of the laser light 7 between the optical fibers 4 becomes longer, and the laser light is transmitted at high speed. It is difficult to divide by time. Also,
The pitch intervals of the optical fibers 4 arranged in a horizontal row are equal to those of the condenser lens 3.
The size of the entire optical system is increased as a result because the size of the optical system cannot be reduced because it is restricted by the arrangement.

Further, in the method of FIG. 5, in order to make the focused spot of the laser beam 7 focused by the focusing lens 3 incident on the end face of the optical fiber 4, the bend mirror 2 for rotary scanning is collected by the optical system. In addition to the requirement that the bend mirror 2 be installed within the region of the focal length f of the optical lens 3, it is necessary to rotate the bend mirror 2 so as not to interfere with the focusing laser 2 and the optical fiber 4 in this range. The size and rotation angle of 2 are greatly restricted.

At this point, the focal length f of the condenser lens 3 is
If a long lens is used, the above-mentioned problem seems to be solved because the mutual distance between the condenser lens 3, the optical fiber 4 and the bend mirror 2 can be made large, but the Y used for processing
The laser output (average power,
When the output energy is large, the beam divergence angle θ of the laser light emitted from the laser oscillator 1 becomes large.
Further, the diameter of the focused beam that has passed through the focusing lens is proportional to the focal length of the lens. On the other hand, in order to make all the laser light 7 condensed by the condenser lens incident on the optical fiber, the condensed spot diameter d is set to the core diameter D of the optical fiber.
It is a necessary condition to make it smaller than that, that is, d ≦ D. On the other hand, the focused spot diameter d that has passed through the focusing lens
Is determined by the divergence angle θ of the laser beam and the focal length f of the condenser lens, and is represented by d = f · θ. Therefore, in order to make all the focused spots enter the core of the optical fiber, it is necessary to configure the optical system so that f.theta..ltoreq.D is established from the above equations. Here, since the divergence angle θ of the laser beam is determined by the performance of the laser oscillator, the focal length f of the condenser lens cannot be made larger than necessary due to the constraint of the above equation, and as a result, in the configuration of FIG. ，
Since the mutual distance between the optical fiber 4 and the rotary scanning bend mirror 2 is limited, the size and rotation angle of the bend mirror 2 are limited.

Considering the conditions for condensing the laser light transmitted through the optical fiber 4 to the processing point by the condensing lens and irradiating the work, the smaller the core diameter of the optical fiber, the condensing spot of the laser light. The diameter is reduced, and the power density of the laser light with which the work is irradiated is increased. For this reason, it is advantageous to use an optical fiber with a small core diameter for the laser processing device.However, when an optical fiber with a small core diameter is used, it is necessary to use a focal length lens as the focusing lens on the incident side. However, it becomes more difficult to rotate the scanning bend mirror with the conventional method of FIG.

Further, in the conventional system shown in FIGS. 4 and 5, the intensity of the laser light distributed from the laser oscillator 1 to the plurality of optical fibers and transmitted is the same for each optical fiber. Machining conditions such as multi-point machining of separate workpieces cannot be handled as they are. SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object thereof is to solve the above-mentioned problems, to enable the use of a condenser lens having a small size and a compact structure and a short focal length, and an emission laser from a laser oscillator. It is an object of the present invention to provide a multi-point processing type laser processing apparatus capable of time-divisionally dividing and transmitting light to a plurality of optical fibers at high speed and efficiently.

[0012]

In order to achieve the above-mentioned object, a laser processing apparatus of the present invention comprises a laser oscillator, a bend mirror provided with its optical axis aligned with the output side of the laser oscillator, and a collector arranged in the subsequent stage. An optical system on the incident side consisting of an integral combination with a light lens, a rotation drive section for rotating the optical system around the bend mirror around the optical axis of the laser oscillator, and a focus position of the condenser lens. It is composed of a plurality of optical fibers whose end faces are aligned and dispersedly arranged on the rotational scanning locus of the focused spot.

Further, based on the above construction, in order to increase the number of divisions of the laser beam, a linear drive for moving an optical system having a bend mirror and a condenser lens in a front-back direction along the optical axis of the laser oscillator. The optical fiber can be configured by dispersively arranging the optical fibers along the linear movement path of the optical system. Further, as a means for adapting to different processing conditions, a plurality of sets of optical systems each including a bend mirror and a condenser lens are integrally combined and arranged side by side on the optical axis of the laser oscillator, and are close to the laser oscillator. There is a configuration in which a beam splitter is adopted as a bend mirror of an optical system, and optical fibers are dispersed and arrayed in the peripheral region of each set of optical systems.

[0014]

In the above structure, the laser light emitted from the laser oscillator is condensed through the bend mirror and the condenser lens, and the condensed spot is incident on the end face of the optical fiber. Here, when the optical system in which the bend mirror and the condenser lens are integrally combined is operated to rotate around the optical axis, the condensing point is scanned so as to move around the rotation center, and is scanned on the scanning locus. The light is sequentially switched to and incident on each of the dispersedly arranged optical fibers by a time division method. In this case, since the bend mirror and the condenser lens are integrally assembled and rotate at the same time, there is no relative movement between them, and the condenser lens is placed on the reflection side of the bend mirror to collect the spot. Since it was made to directly enter the end face of the optical fiber,
A lens with a short focal length can be adopted as a condenser lens without any restrictions. As a result, the focused spot of the laser light can be sufficiently narrowed to be incident on the end face of the core of the optical fiber. Moreover, since the condensing lens is rotated so that the condensing spot is rotated and scanned, it is not necessary to equip the plurality of optical fibers with a one-to-one condensing lens on the incident end side thereof. Even if the optical fibers are arranged at a short pitch, the laser light can be time-divided and incident on and transmitted to the optical fibers without any problem.

Further, by sliding the optical system in which the bend mirror and the condenser lens are combined together along the optical axis at the same time as the above-mentioned rotation operation, the condensed spot of the laser light is changed in the optical axis direction in addition to the rotational direction. Since the optical fibers are also moved, the number of optical fibers to be laid can be increased by arranging the optical fibers three-dimensionally according to the moving area of the focused spot.

Further, a plurality of sets of optical systems each including a bend mirror and a condenser lens are arranged in series on the optical axis, and a beam splitter is adopted as a bend mirror of an optical system close to the laser oscillator, whereby a laser oscillator is provided. After the laser output of is energy-divided to each optical system, it can be time-divisionally transmitted to multiple optical fibers for each optical system.
This makes it possible to handle multi-point machining under different machining conditions.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings of each embodiment, the same parts as those in FIGS. 4 and 5 are designated by the same reference numerals. Embodiment 1 FIGS. 1A and 1B show an embodiment corresponding to claim 1 of the present invention. In this example,
On the output side of the YAG laser oscillator 1, the bend mirror 2 and the condenser lens 3 arranged on the reflection side thereof are integrally incorporated in the housing 8, and the drive motor 9 rotates the housing 8 around the bend mirror 2 as a rotation center. A rotary optical system 10 configured to rotate about an axis O is provided, and the laser beam 7 that has passed through the condenser lens 3 is provided in the peripheral region of the optical system 10.
A plurality of optical fibers 4 are dispersed and arrayed with their end faces aligned with the movement locus X of the focal point. Each optical fiber 4 is drawn out and wired toward the processing point of the work as shown in FIG.

With such a configuration, the laser light 7 emitted from the laser oscillator 1 is reflected by the bend mirror 2 of the optical system 10 in a right angle direction and then passes through the condenser lens 3 to be condensed. 4 is incident on the end face of the core. Here, when the optical system 10 is rotated around the optical axis O by the drive motor 9, the focused spot of the laser light 7 orbits on the movement locus X shown in FIG. While scanning the end face 4 of the laser beam, the laser light is time-divided in this scanning process and sequentially enters each optical fiber 4, and is transmitted through the optical fiber 4 to the processing point of the workpiece in time series.

In this case, if the end faces of the optical fibers 4 are arranged so as to be located on the movement locus X of the focused spot, the number of laying lines is not limited, and adjacent optical fibers are brought close to each other so that they are almost in contact with each other. Arrangement in the open state is also possible. Embodiment 2: FIG. 2 shows an embodiment corresponding to claim 2 of the present invention. In addition to the configuration of the first embodiment, this embodiment includes a slide mechanism 11 that linearly moves the optical system 10 along the optical axis O in the arrow P direction between the solid line position and the dotted line position. The optical fibers 4 are distributed and arrayed in the peripheral region along the linear movement path of the optical system 10 as in FIG.

With this structure, the optical system 10 is connected to the drive motor 9
When the optical system 10 is linearly moved by the operation of the slide mechanism 11 while rotating by, the condensing point of the laser light 7 that has passed through the condensing lens 3 and is condensed is linear with the optical axis O in the rotational direction. The laser beam is incident on each optical fiber 4 distributed in the peripheral region of the optical system 10 in a time division manner during the scanning process.

According to this embodiment, it is possible to dramatically increase the number of optical fibers 4 as compared with the first embodiment. In addition, since the bend mirror 2 and the condenser lens 3 slide integrally in the linear direction P, the optical fibers 4 arranged in the linear direction are laid so as to be close to each other without any restriction on the pitch interval. In addition, by reducing the arrangement pitch between the optical fibers, the moving distance of the optical system 10 can be reduced, and the advantage that the laser light can be time-divided at high speed can be obtained.

The rotary drive motor 9 in the illustrated embodiment is omitted, and the optical system 10 is moved only linearly. In response to this, the optical fibers 4 are dispersed and arranged in a line toward the focusing point of the focusing lens 3. It is also possible to carry out. Embodiment 3: FIG. 3 shows an embodiment corresponding to claim 3 of the present invention. In this embodiment, the time division method and the energy division method of the laser light described in the above-mentioned embodiments are used together so that multi-point processing under different processing conditions can be supported. Two sets of optical systems arranged side by side along the optical axis O are incorporated in the housing 8 of the optical system 10 interposed between the optical system 10 and the fiber 4. Bend mirror 2 as in the previous embodiment
The beam splitter 2a is used as a bend mirror of an optical system that is arranged on the side closer to the laser oscillator 1 in particular.

With this structure, a part of the laser light 7 emitted from the laser oscillator 1 is reflected by the beam splitter 2a at a right angle and then passes through the condensing lens 3 so that the condensing spot is on the end face of the optical fiber 4. Incident. The remaining laser light that has passed through the beam splitter 2a is reflected by the bend mirror 2 of the optical system that is lined up on the rear stage side, and the condenser lens 3 is used.
And enters the other optical fiber 4. In this case, if the ratio between the reflectance and the transmittance of the beam splitter 2a is selected to be, for example, 6: 4, 7: 3, the laser beam 7 is energy-divided into two optical systems corresponding to this ratio. Therefore, it is possible to realize a flexible laser processing system capable of simultaneously performing multi-point processing under different processing conditions, that is, changing the light intensity. When the optical system 10 is rotated around the optical axis O by the drive motor 9, the energy splitting and the energy splitting are performed on a plurality of optical fibers dispersedly arranged in the peripheral region for each of the two optical systems. In addition, the laser light can be time-divided to perform time-series multi-point processing.

[0024]

As described above, the laser processing apparatus of the present invention has the following effects. That is, according to the configurations of claims 1 and 2, the optical system in which the bend mirror and the condenser lens are integrally combined and interposed between the laser oscillator and the optical fiber is used for the laser light emitted from the laser oscillator. Since it is configured to rotate or slide on the optical axis, the laser light is time-divided at high speed and transmitted to the processing point of the workpiece for the multiple optical fibers laid facing the optical system. Multi-point processing can be performed. Further, in this case, the arrangement of the optical fibers is not restricted by the bend mirror, the condenser lens, etc., and the optical fibers can be laid close to each other to reduce the size of the entire optical system.
In particular, the condenser lens is arranged on the reflection side of the bend mirror so that the laser light condensed spot is directly incident on the end face of the optical fiber core. Can be efficiently incident on the core end surface of the optical fiber.

Further, by adopting the structure of claim 3, it is possible to cope with multi-point machining under different machining conditions by using both time division and energy division methods for the laser light emitted from the laser oscillator. A flexible laser processing system can be realized.

[Brief description of drawings]

1A and 1B are configuration diagrams of an optical system of a laser processing apparatus according to a first embodiment of the present invention, in which FIG. 1A is a side view and FIG. 1B is a front view seen from an optical axis direction.

FIG. 2 is a configuration diagram of an optical system of a laser processing apparatus according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of an optical system of a laser processing apparatus corresponding to a third embodiment of the present invention.

FIG. 4 is a block diagram of an optical system of a conventional laser processing apparatus using a time division method.

5 is a configuration diagram of an optical system of a laser processing apparatus of a conventional example different from FIG.

[Explanation of symbols]

 1 Laser Oscillator 2 Bend Mirror 2a Beam Splitter 3 Condenser Lens 4 Optical Fiber 7 Laser Light 9 Drive Motor (Rotation Drive Unit) 10 Optical System 11 Slide Mechanism (Linear Drive Unit) O Optical Axis

Claims (3)

[Claims] 1. A multi-point processing type laser processing apparatus for transmitting laser light emitted from a laser oscillator to a processing point of a work through a plurality of optical fibers, the laser oscillator and an optical axis on an output side of the laser oscillator. An optical system on the incident side, which is an integrated combination of a bend mirror and a condenser lens arranged in the subsequent stage, and the optical system is rotated around the optical axis of the laser oscillator around the bend mirror. A laser processing apparatus comprising: a rotation driving unit; and a plurality of optical fibers whose end faces are aligned with a focal position of the condenser lens and are dispersedly arranged on a rotation scanning locus of a condensed spot. 2. The laser processing apparatus according to claim 1,
A linear driving unit that slides the optical system consisting of a bend mirror and a condenser lens in the front-back direction along the optical axis of the laser oscillator is provided, and the optical fibers are distributed and arranged along the linear movement path of the optical system. Laser processing equipment characterized by. 3. The laser processing apparatus according to claim 1,
A plurality of sets of optical systems consisting of a bend mirror and a condenser lens are integrally combined and arranged side by side on the optical axis of the laser oscillator, and a beam splitter is adopted for the bend mirror of the optical system close to the laser oscillator. A laser processing apparatus characterized in that optical fibers are distributed and arranged in the peripheral region of each set of optical systems.