JPS6232717Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a laser cutter that has a small cutting allowance and is capable of cutting thick materials.

Laser cutters have many advantages, such as being able to be applied to cutting any material and not applying any cutting force to the material to be cut. For this reason,
Their use in various fields is being considered, and many have been put into practical use, as seen in the cutting of paper such as corrugated paper.

Conventional laser cutters like this one converge the energy beam emitted from the laser oscillator using a condensing spherical lens, which has the disadvantage that the beam becomes conical and the cutting margin becomes large. If you tried to cut them in a stacked state, it would be necessary to make the focal length of the condensing spherical lens very long. However, this significantly increases the space occupied by the laser cutter, so the laser cutter was essentially considered unsuitable for cutting thick materials.

The object of the present invention is to provide a laser cutter of a new structure which overcomes the essential drawbacks of conventional laser cutters and enables cutting of thick materials.

The structure of the laser cutter of the present invention that achieves this purpose is that the tip of the laser oscillator that emits parallel energy beams is formed by an arcuate surface with a constant radius of curvature from the center axis of curvature, and the energy beam is converged into a line. Place the first converging optical system to
The energy is linearly converged at or near the focal line position of the first converging optical system with a surface component in a direction perpendicular to the central axis of curvature having a focal length equal to that of the first converging optical system. a saddle-shaped curved surface having an arc shape that converts the beam into a film-like parallel beam, and whose surface component in a direction parallel to the central axis of curvature forms an arc shape that converges the film-like parallel beam into a point; The present invention is characterized in that a second converging optical system is arranged.

That is, as shown in FIG. 1, which represents the principle of the present invention, an energy beam 12 continuously emitted from the laser oscillator 11 is placed at the tip of the laser oscillator 11.
A convex cylindrical lens 13 that linearly converges the parallel light beam is arranged as a first converging optical system,
The convex cylindrical lens 1 is located at or near the focal line position of the convex cylindrical lens 13.
A concave cylindrical lens 14 for converting the linearly converged energy beam 12' having a focal length equal to The convex cylindrical lens 15 that converges the film-like parallel beam 12'' into a point can be placed on the work table 16 so that its central axis of curvature is 90 degrees different from the central axis of curvature of the convex cylindrical lens 13. Although it is possible to cut a fixed workpiece 17, the present invention realizes the functions of the above-described concave cylindrical lens 14 and convex cylindrical lens 15, respectively, in one optical system.

Hereinafter, one embodiment of the laser cutter according to the present invention will be described in detail with reference to FIG. 2 showing its schematic structure. In this embodiment, a convex cylindrical lens 13 formed by an arcuate surface having a constant radius of curvature from the central axis of curvature is arranged as a first converging optical system that converges the parallel light beam into a linear shape.
At or near the focal line position of this convex cylindrical lens 13, the convex cylindrical lens 1
The surface component in the direction perpendicular to the central axis of curvature of No. 3 has a focal length equal to that of the convex cylindrical lens 13 and has a convex arc shape that converts the linearly converged energy beam 12' into a film-like parallel beam. A reflecting mirror 19 is provided with a saddle-shaped curved surface 18 whose surface component in a direction parallel to the center axis of curvature is a concave arc that converges the film-like parallel beam into a point. It is installed as an optical system for use. This reflector 1
9, the curved surface 1
8 is plated with gold, and the surface component in the direction perpendicular to the central axis of curvature of the convex cylindrical lens 13 is the concave cylindrical lens 1 shown in FIG.
4, and the surface component in the direction parallel to the center axis of curvature functions as the convex cylindrical lens 15 shown in FIG.

These convex cylindrical lens 13 and reflecting mirror 19 are housed in a dustproof tube 20.
In order to prevent dust from adhering to the arc surface of the convex cylindrical lens 13 and the curved surface 18 of the reflecting mirror 19 and causing damage due to heat absorption, the convex cylindrical lens 13 and the curved surface 18 of the reflecting mirror 19 are cleaned. A gas supply pipe 21 for spraying nitrogen gas is installed. The workpiece 17 is fixed on a worktable 16 that is installed obliquely in front of a reflecting mirror 19 that is inclined with respect to the optical axis of the convex cylindrical lens 13 and that can be fed and moved in a direction parallel to the central axis of curvature of the convex cylindrical lens 13. Between the dustproof tube 20 and the laser oscillator 11, there is a mirror shutter 22 that controls the feeding of the energy beam 12 to the workpiece 17.
A water tank 23 is installed on the side of the laser oscillator 11 to absorb the heat of the energy beam 12 which is tilted at 45 degrees with respect to the optical axis of the mirror shutter 22 and bent laterally by 90 degrees.

When cutting the work 17, the work table 16 is moved left and right according to the cutting position, and then the mirror shutter 22 is opened and the work table 16 is raised to cut the work 17. In this case, the cutting distance depends on the width of the cutting beam 12, but in this embodiment, it can be adjusted by moving the convex cylindrical lens 13 in the direction of its optical axis, and it is possible to narrow down to a linear shape of about 0.5 mm. Therefore, it can be extremely reduced. Furthermore, since the degree of convergence of the cutting beam 12 is increased, it is now possible to cut a workpiece 17 that is thicker in the optical axis direction than in the conventional method.

In this embodiment, a cooling water supply pipe 24 for spraying cooling water on the back surface of the reflecting mirror 19 to cool the reflecting mirror 19 is incorporated in the dustproof tube 20.

The embodiment described above is suitable for a laser oscillator 11 with an output of up to about 300 watts, but for a laser oscillator 11 with an even higher output, it is preferable to use a reflective optical system, as shown in FIG. 2a. As shown in FIG. 3, another embodiment of the present invention is constructed with a cylindrical concave mirror 25 instead of the convex cylindrical lens 13. It is preferable to attach a cylindrical concave mirror 25 and a cylindrical concave mirror 25 to improve the cooling efficiency.

Note that when the energy beam 12 is too strong, it is desirable to expand its diameter in advance and then make it incident on the first converging optical diameter.

In the above embodiment, the object of the present invention was achieved by using the reflecting mirror 19, but as is well known, the same object can be achieved even if the reflecting mirror is replaced with a lens. FIG. 4 shows still another embodiment of the present invention in which a lens 19' is used in place of the reflecting mirror 19. That is, at or near the focal line position of the convex cylindrical lens 13, a surface component in a direction perpendicular to the central axis of curvature of the convex cylindrical lens 13 has a focal line distance equal to that of the convex cylindrical lens 13, and a linear shape is formed. a concave arc shape that converts the energy beam 12' converged into a film-like parallel beam, and a convex shape whose surface component in a direction parallel to the central axis of curvature converges the film-like parallel beam into a point shape; A lens 19' having a saddle-shaped curved surface 18' having an arc shape is arranged as a second converging optical system. As shown in FIG. 4b, which shows the appearance of this lens 19', the unevenness relationship of each surface component is reversed from that of the reflecting mirror 19 shown in FIG. 2a, and the central axis of curvature of the convex cylindrical lens 13 is The surface component in the direction perpendicular to
It functions as the concave cylindrical lens 14 shown in the figure, and the surface component in the direction parallel to the central axis of curvature functions as the convex cylindrical lens 15 shown in FIG. Therefore, in this embodiment using the lens 19', as well as in the embodiment using the reflecting mirror 19, excellent cutting is achieved.

In addition, since a carbon dioxide laser oscillator is used in these embodiments, it is preferable to use a lens made of a transparent material in the infrared region or a reflective mirror made of copper plated with gold.

In this way, according to the laser cutter of this invention,
Since the energy beam from the laser oscillator is converted into a film-like parallel beam and then converged into a point shape to cut the workpiece, it is possible to significantly reduce the cutting allowance. Thicker workpieces can be cut by the reduced amount. In addition, the two optical elements 1 shown in FIG.
4,15 functions in one optical element 19 or 1
9', the number of parts of the laser cutter can be reduced and the size can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram of the laser cutter according to the present invention, Fig. 2a is a plan view showing the schematic structure of one embodiment thereof, and Fig. 2b is a perspective view showing the appearance of the reflecting mirror shown in Fig. 2a. , FIG. 3 is a plan view showing the schematic structure of an optical system according to another embodiment of the present invention, and FIG. 4 a
is a plan view showing a schematic structure of yet another embodiment of the present invention, and FIG. 4b is a perspective view showing the external appearance of the lens shown in FIG. ,12',1
2''...Energy beam, 13...Convex cylindrical lens, 17...Work, 18...Curved surface, 18'...Curved surface, 19...Reflector, 19'...
...Lens, 25... It is a cylindrical concave mirror.

Claims (1)

[Scope of utility model registration request] A first focusing optical system is disposed at the tip of a laser oscillator that emits a parallel energy beam, and is formed by an arcuate surface having a constant radius of curvature from the central axis of curvature, and that focuses the energy beam into a line. The energy beam, which is linearly converged at or near the focal line position of the first converging optical system, with a surface component in a direction perpendicular to the central axis of curvature having a focal length equal to that of the first converging optical system, is converged into a film shape. a second converging surface having a saddle-shaped curved surface having an arc shape for converting the film-like parallel beam into a point-like shape, and having a surface component in a direction parallel to the central axis of curvature converging the film-like parallel beam into a point shape; A laser cutter characterized by the arrangement of an optical system.