JP2000071088A - Laser processing machine - Google Patents

Abstract

(57) [Summary] [Problem] Without sacrificing the processing speed and processing quality,
An object of the present invention is to provide a laser processing machine capable of processing a wide range of workpieces, and capable of remotely controlling and easily changing a laser beam diameter. SOLUTION: A laser beam diameter varying means 2 is provided, and the laser beam diameter φD incident on the light condensing means is adjusted by the laser beam.
The diameter of the workpiece is controlled by the variable diameter means 2 according to the workpiece.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser beam machine for performing laser processing such as cutting on a workpiece by relatively moving a focused laser beam and the workpiece. The present invention relates to a laser processing machine having diameter changing means.

[0002]

2. Description of the Related Art In a laser beam machine, a laser beam emitted from a laser oscillator is guided to a focusing means such as a lens by an optical system such as a mirror, and the laser beam focused by the focusing means is applied to a workpiece. By irradiating, the workpiece is subjected to laser processing such as cutting.

[0003] In the above-mentioned laser beam machine, it has been known that the light condensing state such as the spot diameter of the light condensing part changes depending on the focal length of the light condensing means, the diameter of the beam incident on the light condensing means and the like. It is also known that the state of the laser beam at the focusing section affects the result of laser processing.

Therefore, it has been customary to select the focal length of the light condensing means and the diameter of the beam incident on the light condensing means so as to obtain a desired laser processing effect.

In general, a laser beam is slightly diffused. In an optical scanning type laser beam machine, a constant optical path length is used to suppress a change in the diameter of an incident beam to a focusing means due to the laser beam diffusion. Means were sometimes used.

That is, the prior art is based on the technical idea of stabilizing the state of the laser beam in the condensing part by reducing the change in the diameter of the incident beam to the condensing means. Is to be processed with the same focused laser beam.

[0007] However, in laser processing, originally,
While there is an optimal light-condensing state according to the workpiece, the conventional technology has been selected so that a wide range of workpieces can be processed safely, so depending on the workpiece, The processing speed and processing quality had to be sacrificed.

Further, in the prior art, in order to remotely control the diameter of a laser beam, the divergence of the laser beam is used to control the entire distance of the beam transmission or to have a curvature inserted into the beam path. Since the insertion position of the optical component has to be controlled, there is a problem that the device becomes large-scale.

[0009]

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, the present invention enables processing of a wide range of workpieces without sacrificing the processing speed and processing quality, and also enables remote control. It is an object of the present invention to provide a laser beam machine capable of changing a laser beam diameter as easily as possible.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a laser processing machine according to the present invention comprises a laser beam diameter varying means, and adjusts a laser beam diameter incident on a focusing means. The laser beam diameter varying means is controlled in accordance with the material to be processed. In an optical scanning laser beam machine, the diameter of the laser beam incident on the focusing means is controlled by the laser beam. The diameter of the workpiece is controlled by the diameter varying means in accordance with the workpiece and the optical path length.

Thus, the laser beam diameter changing means is configured to be able to change only the distance between a plurality of lenses without rotating the lenses.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a laser beam transmission system in one example of the laser beam machine of the present invention, FIG. 2 is a configuration diagram of a laser beam variable unit in one example of the laser beam machine of the present invention,
FIG. 3 is a block diagram of another example of the laser beam varying means, and FIG. 4 is a control block diagram of an example of the laser beam machine of the present invention.

In the figure, 1 is a laser oscillator, 2 is a laser beam diameter varying means, 3 is a mirror, 4 is a condenser lens,
The laser beam LB emitted from the laser oscillator 1 is guided to the condenser lens 4 via the beam diameter varying means 2 and the mirror 3 and is focused, and is irradiated on a workpiece (not shown) near the condenser part. Laser processing such as cutting and the like is performed.

In FIG. 1, FL is the focal length of the condenser lens 4, φD is the diameter of the beam incident on the condenser lens 4, and φd is the spot diameter of the condenser. The state of the laser beam at the focusing section such as the spot diameter φd is determined by the focal length of the focusing lens 4.
It greatly depends on FL and the diameter φD of the incident beam to the condenser lens 4. For example, when the condenser lens 4 having the same focal length FL is used, the spot diameter becomes larger as the diameter φD of the incident beam on the condenser lens 4 increases. φd becomes smaller, and the laser energy applied to the workpiece is concentrated, making it suitable for cutting relatively thin plates in cutting applications. Conversely, for example, the smaller the incident beam diameter φD to the condenser lens 4 is, the larger the spot diameter φd is, and at the same time, the smaller the beam diameter change near the condensing part is, which is relatively suitable for cutting a thick plate. It is.

The beam diameter changing means 2 comprises a concave lens 2a and a convex lens 2b, and the convex lens 2b can be moved relative to the concave lens 2a by a driving means (not shown) which can be remotely operated in the traveling direction of the laser beam LB. It has become.

Thus, the laser beam LB expanded by the concave lens 2a is suppressed from expanding by the convex lens 2b,
The beam diameter of the laser beam LB after passing through the laser beam diameter varying means 2 can be changed depending on the insertion position of the convex lens 2b. That is, by controlling the laser beam diameter varying means 2, the incident beam diameter φ
D can be changed, and the state of the laser beam such as the spot diameter φd of the condensing part can be controlled. In FIG. 1, reference numeral 5 surrounded by a dotted line denotes a light collecting unit.

The laser beam diameter varying means 2 is not limited to the configuration shown in FIG. 1, but may have the configuration shown in FIG. 2, for example. That is, in FIG. 2, reference numeral 6 denotes a laser beam diameter varying means, and a laser beam LB emitted from the laser oscillator 1 is turned back by a mirror 6a, and a curvature variable mirror is provided.
It is incident on 6b. The curvature variable mirror 6b is capable of remotely controlling the curvature of the reflecting surface by a piezoelectric actuator (not shown) or the like. By controlling the curvature variable mirror 6b, the curvature after passing through the laser beam diameter varying means 6 is controlled. The beam diameter of the laser beam LB can be changed. The beam diameter varying means is not limited to the above, and a conventional method of controlling the entire distance of laser beam transmission may be used.

FIG. 3 shows another example of the laser beam diameter varying means, in which 11 is a first lens holder on which a first lens 12 is mounted, and 13 is a second lens on which a second lens 14 is mounted. In the holder, the first lens 12 expands the laser beam LB, and the second lens 14 suppresses the expansion of the laser beam LB.

In FIG. 3, reference numeral 11a denotes a first lens holder 11;
A guide pin 13a fixed to the outer surface of the second lens holder 13 is a guide groove formed in the second lens holder 13 in the axial direction. The head of the guide pin 11a is inserted into the guide groove 13a. Reference numeral 15 denotes an adjustment ring fitted to the outer periphery of the first lens holder 11 so as to be rotatable and immovable in the axial direction and screwed to the second lens holder 13. In the example of FIG. 3, when the adjustment ring 15 is rotated, Second
The lens holder 13 moves in the axial direction while being guided by a guide pin 11a whose head is inserted into the guide groove 13a. In the present invention, since the first lens holder 11 and the second lens holder 13 only need to move relatively, the first lens holder 11 may be moved with respect to the second lens holder 13.

In FIG. 3, 16 is a motor, 17 is a driving pulley, 18 is a transmission belt for transmitting the rotation of the motor 16 to the adjusting ring 15 via the driving pulley 17, and when the motor 16 is driven,
The adjustment ring 15 is rotated, and the second lens 14 moves only in the axial direction without rotating integrally with the second lens holder 13, and moves only by the axial distance between the first lens 12 and the second lens 14. Can be changed relatively.

The motor 16 is provided with an encoder (not shown) so that the distance between the first lens 12 and the second lens 14 can be remotely controlled and grasped. In the above example, the first lens 12 is a magnifying lens and the second lens 14 is a reducing lens. However, the first lens may be a reducing lens and the second lens may be a magnifying lens.

Next, the configuration of a control unit for controlling the laser beam machine according to the present invention will be described with reference to FIG. In FIG. 4, reference numeral 21 denotes a computer, which is a main control unit for controlling the entire laser processing machine. Although not shown, an input device such as a keyboard for inputting processing conditions such as the material and thickness of a workpiece and a processing shape program. It has. Reference numeral 22 denotes a beam diameter varying unit control unit connected to the main control unit 21. The beam diameter varying unit control unit 22 is connected to an optimum beam diameter data management unit 23 and a beam diameter varying unit 24. Based on the processing conditions such as the material and thickness of the workpiece input to the section 21, the beam diameter varying means control section 22 refers to the optimum beam diameter data management section 23 to process the beam diameter varying means 24. The beam diameter is controlled so as to be optimal for the material. In FIG. 4, reference numeral 25 denotes an optical path length VS beam diameter data management unit connected to the beam diameter variable means control unit 22 when the processing machine is a beam scanning laser beam machine.

In the case of a laser beam machine of the beam scanning type, laser processing is performed by moving the focusing unit 5 in FIG. 1, so that the distance between the beam diameter varying means 2 and the focusing lens 4 changes. May change the diameter φD of the incident beam to the condenser lens 4. In this case, the optical path length from the machining shape program input to the main control unit 21 to the machining position can be known. By connecting the optical path length VS beam diameter data management unit 25 to the beam diameter variable unit control unit 22, the beam diameter variable unit control unit 22 illuminates the optical path length VS beam diameter data management unit 25, and outputs a laser beam corresponding to the optical path length. With the beam expansion or contraction corrected, the beam diameter varying means 24 can be controlled so as to have an optimum beam diameter for the workpiece.

The optical path length VS beam diameter management unit 25
Can be constituted by a data table of the beam diameter varying means 24 or can be constituted by optical calculation. Further, by providing a beam diameter measuring means, the measured value can be used, and in addition, a change in the beam diameter due to a change with time can be corrected.

In addition to controlling the beam diameter in accordance with the processing conditions such as the material and plate thickness of the workpiece input to the main control unit 21, other processing conditions such as the focal length and the laser output are appropriately adjusted. May be changed.

[0026]

As described above, the present invention has a laser beam diameter varying means and a laser beam diameter incident on the condensing means can be controlled in accordance with the material to be processed. Processing of a wide range of workpieces can be performed in a beam state of the light-collecting portion that is optimal for the workpieces without sacrificing the processing quality.

Further, since the diameter of the incident beam to the light condensing means can be controlled according to the material to be processed and can be controlled according to the optical path length, the expansion or contraction of the laser beam due to the change in the optical path length can be reduced. Can be corrected.

Further, since the laser beam diameter can be changed by remotely controlling only the distance between a plurality of lenses without rotating the lens, the laser beam diameter can be remotely variably controlled with a simple configuration. it can.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a laser beam transmission system in an example of a laser processing machine of the present invention.

FIG. 2 is a configuration diagram of a laser beam varying unit in one example of the laser beam machine of the present invention.

FIG. 3 is a configuration diagram of another example of a laser beam variable unit.

FIG. 4 is a control block diagram of an example of the laser beam machine according to the present invention.

[Explanation of symbols]

 LB Laser beam φD Incident beam diameter φd Spot diameter FL Focal length 1 Laser oscillator 2 Laser beam variable means 2a Concave lens 2b Convex lens 3 Mirror 4 Condensing lens 5 Condensing unit 6 Laser beam variable means 6a Mirror 6b Curvature variable mirror 11 First lens Holder 11a Guide pin 12 First lens 13 Second lens holder 13a Guide groove 14 Second lens 15 Adjustment ring 16 Motor 17 Drive pulley 18 Transmission belt 21 Main control unit 22 Beam diameter variable unit control unit 23 Optimal beam diameter management unit 24 Beam Diameter variable means 25 Optical path length VS Beam diameter data management unit

Claims (4)

[Claims] 1. A laser comprising a laser beam diameter varying means, wherein the laser beam diameter incident on the condensing means is controlled by the laser beam diameter varying means according to a workpiece. Processing machine. 2. A laser beam diameter varying means, wherein a laser beam diameter incident on the focusing means is controlled by the laser beam diameter varying means according to a workpiece and an optical path length. Optical scanning laser beam machine. 3. The laser beam machine according to claim 1, wherein the laser beam diameter changing means can change a distance between a plurality of lenses without rotating the lenses. 4. A mechanism for changing a distance between a plurality of lenses without rotating a lens, wherein the mechanism is fixed to a first lens holder on which a first lens is mounted, and is mounted in an axial direction of a second lens holder on which a second lens is mounted. A guide member inserted into the groove,
4. The laser according to claim 3, comprising a rotating member screwed into the second lens holder and restricted in axial movement by the first lens holder, and a remotely operable driving means for driving the rotating member. Processing machine.