JPH0238255Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an optical device for splitting laser beams, and particularly relates to an optical device for splitting laser beams suitable for use when performing laser hardening processing.

[Background of the idea]

Laser hardening is one of the surface treatment methods for metal members. In this method, a laser beam is irradiated onto the surface to be processed while moving the laser beam and the surface to be processed relative to each other to heat the surface, and after the laser beam passes, the material is rapidly cooled by diffusion of heat into the material. This is how it was done.

This laser hardening requires only a thin surface layer to be heated, so the total amount of heat input is small, and since the cured product is hardly deformed by thermal strain, troublesome post-processing is unnecessary or reduced. It is also possible to harden cast iron, which was conventionally avoided for fear of quenching cracks, as long as light can reach parts of complex shapes, such as the inner surface of pipes and narrow grooves. It is possible to partially harden materials such as materials, and since it can be processed in the atmosphere, there is no need for a vacuum chamber during electron beam processing or a charcoal furnace for normal hardening, and there are no restrictions on the size of the workpiece. Features include: clean and pollution-free quenching that does not require water or oil; hardening depth, hardening area, etc. can be precisely controlled; and online processing is possible due to short processing times.

However, when performing this laser hardening, the laser beam and the surface to be treated are moved relative to each other, so when forming a large number of parallel hardened zones, the laser beam is scanned and hardened. The bands are formed one by one, and therefore, when forming such a large number of parallel quench-hardened bands, the processing time becomes long.

In order to shorten the processing time, it is possible to increase the laser output and the beam movement speed, but this may complicate the movement mechanism, reduce the precision of hardening, and reduce the depth of hardening. Therefore, it cannot be said to be an appropriate method.

[Purpose of invention]

The present invention has been made in view of the above circumstances, and its purpose is to provide an optical device for splitting laser beams that can harden a plurality of locations at the same time.

[Structure of the idea]

In order to achieve this purpose, the optical device of the present invention divides the laser beam by arranging reflective mirrors of a specific shape at intervals. This is an optical device comprising a plurality of reflecting mirrors arranged with a distance between them so that the angle of the reflection is reduced, and the reflecting mirrors have a cross-sectional shape of a triangular shape or a shape having an acute vertex angle of 20 degrees or less. The object of the present invention is to provide an optical device for splitting laser beams, which has a substantially triangular prism shape and is characterized in that the reflecting mirrors are arranged with their sharp apex angles pointing toward the same side.

[Example of idea]

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

1 to 4 are diagrams showing an optical device for splitting laser beams according to an embodiment of the present invention.

In the laser beam splitting optical device according to this embodiment, as shown in FIG. In this example, 4
) reflectors 1 are spaced apart from each other and their sharp apex angles 2 are on the same side (upper side in the example of FIG. 1).
are arranged so as to point to The ends 8 of these reflecting mirrors in the height direction of the triangular prisms are connected to a frame-shaped support member 9 and are integrated. Note that a surface 9m of the frame body 9 that faces the mirror surface 3 is an inclined reflective mirror surface similar to the mirror surface 3.

By arranging the reflecting mirrors 1 in this way, the laser beam 4 is directed to the mirror surface 3 of the reflecting mirror 1, as shown in FIG.
The energy is reflected and divided into uniform energy densities. By installing this laser beam splitting optical device close to the surface 6 of the member to be hardened 5 to be hardened, it is possible to simultaneously harden a plurality of locations on the surface 6. (7 in Figure 2 indicates the part during quenching.) Therefore,
By moving the device of the present invention integrally with the laser light source near the surface of the member 5 to be hardened (or by moving the member 5), it is possible to form a large number of hardened zones in one movement. can.

FIG. 3 is a diagram showing another embodiment of the optical device for laser beam splitting of the present invention, in which a is a plan view, b is a sectional view taken along line B-B in a, and c is a line C-C in a. FIG. In FIG. 3, the reflecting mirror 1 is held at both ends of the triangular prism in the height direction connected to a supporting member 9. As shown in FIG. In this embodiment, however, the side surface 10 of the support member 9 on the side to which the reflector is connected is a mirror surface that is inclined in the direction of the sharp apex angle 2 of the reflector. By making the side surface 10 also a mirror surface in this way, the energy distribution of the laser beam becomes even more uniform, and the focusing characteristics of the laser beam are further improved.

In the embodiments shown in FIGS. 1 to 3, the cross-sectional shape of the reflecting mirror 1 is a triangle having a sharp vertex angle of 20 degrees or less, but in the present invention, the cross-sectional shape of the reflecting mirror 1 is may be approximately triangular, that is, may have a shape approximating a triangle. Examples of such devices include those having cross-sectional shapes as shown in FIGS. 4a and 4b, for example. Fig. 4a shows a triangular shape 12 with a concavely curved reflective surface 11, b
1 has a triangular shape with a convexly curved reflective surface 13
4 is shown.

As shown in FIG. 4a or b, a laser beam splitting optical device equipped with a reflecting mirror with a curved reflecting surface can split laser beams having various intensity distributions and make the energy uniform. Therefore, it is possible to perform hardening with appropriate hardening depth and width using laser beams having various intensity distributions.

In addition, in the present invention, the angle of the apex angle of the triangle of the cross section of the reflecting mirror (the angle indicated by θ in Fig. 3b) is
The temperature should be 20 degrees or less, preferably 10 degrees or less.

Note that in order to prevent the influence of heating by the laser beam, a cooling means (for example, a cooling pipe) may be installed inside the reflecting mirror.

[Effect of idea]

As described in detail above, according to the laser beam splitting optical device of the present invention, laser light can be split into a plurality of light beams very easily. Therefore, by using the optical device for laser beam splitting of the present invention, it is possible to harden multiple locations at the same time, and work efficiency is greatly improved. Furthermore, by appropriately selecting the spacing, angle, etc. of the reflecting mirrors, various hardened patterns can be formed, which is extremely advantageous industrially.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional diagram showing an embodiment of the optical device for laser beam splitting of the present invention, FIG. 2 is a cross-sectional view showing the laser beam splitting situation of the device of FIG. 1, and FIG. 3 is the device of the present invention. FIG. 3 is a diagram showing another example of
FIG. 3a is a plan view, FIG. 3b is a sectional view taken along the line B--B in FIG. 3a, and FIG. 3c is a sectional view taken along the line C--C in FIG. 3a. FIGS. 4a and 4b are cross-sectional views of a reflecting mirror according to still another embodiment. 1...Reflector, 2...Sharp vertex angle, 3...Mirror surface,
4... Laser light, 5... Member to be hardened, 7... Hardening, 8... End, 9... Supporting member.

Claims (1)

[Claims for Utility Model Registration] (1) An optical device comprising a plurality of reflecting mirrors arranged with a space between them so that incident light passes through either as is or after being reflected. The reflecting mirrors have a cross-sectional shape of a triangular or almost triangular prism having an acute apex angle of 20 degrees or less, and these reflecting mirrors are arranged with their acute apex angles facing the same side. An optical device for laser beam splitting, characterized in that: (2) Each of the reflecting mirrors has its triangular prism height direction end connected to a support member, and the side surface of the supporting member on the side where the reflecting mirror is connected is a mirror surface that opens and slopes in the direction of the pointed apex angle. An optical device for laser beam splitting according to claim 1, which is characterized in that: