JPS62179882A - Heating method by laser beam - Google Patents

Abstract

PURPOSE:To perform the preheating of the body to be heated with good efficiency by a simple device by preheating the face to be heated by the subbeam of the beam divided by a beam splitter and by heating it with the main beam by moving the preheated face part to be heated to the main beam projecting part. CONSTITUTION:About 90% of the laser power of the laser beam 2 emitted from a laser oscillator 1 is projected on the outer peripheral face 12 of the body 11 to be heated as a main beam 7 by being reflected by a beam splitter 4 and the subbeam 9 which passed through the beam splitter 4 is projected on the outer peripheral face 12 of the body 11 to be heated with its total reflection by a bend mirror 5. The preheating of the outer peripheral face 12 is started by the beam spot 13 of the subbeam 9 by turning the body 11 to be heated from the preheating side to the heating side in the arrow mark direction Y and the projection of the main beam 7 is started from the time when this preheated part arrived at the beam spot 10 position to perform the main heating of the preheating part. Since the preheating and heating are performed by one unit of laser oscillator 1 in this way the device is simplified and it is economical.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method of heating a heated object using a laser beam.

(Prior art) For example, as a method for depositing hard metal powder on the face of an engine valve to form a hardened layer, a method uses a laser beam that can easily locally heat the hard metal powder as a heat source for melting the hard metal powder. has been recently adopted. It is preferable to preheat the base material as a pre-process for this metal filling, but this preheating is generally performed using a gas burner, heating furnace, or the like.

(Problem to be solved by the invention) However, according to the above preheating method, a heat source for preheating is required separately from the laser generator, and it is not possible to locally preheat only the necessary parts of the object to be heated. Moreover, since the product is cooled after preheating before proceeding to the next process, there is a problem in that energy efficiency is poor.

This invention solves the above-mentioned conventional problems, and aims to provide a heating method using a laser beam that can efficiently preheat an object to be heated using a simple device.

(Means for Solving the Problems) In order to achieve the above object, in the heating method using a laser beam of the present invention, a laser beam emitted from a laser oscillator is split into a main beam and a sub beam using a beam splitter. The upper beam and the sub-beam are irradiated to a position near the heated surface of the object to be heated, the sub-beam preheats the heated blood, and the preheated heated surface is irradiated with the main beam. , and heating is performed by the main beam.

(Function) In the heating method using a laser beam of this invention,
Of the main beam and sub-beam obtained by splitting the laser beam by a beam splitter, first the heated blood of the object is preheated by the sub-beam, and then this preheated heated surface is heated near the sub-beam irradiation part. The main beam irradiates the main beam and heats the main beam (main heating). In this way, preheating and heating of the heated object H are performed using the same laser oscillator, and since both the irradiation positions of the main beam and the sub beam are located in close proximity, the preheating by the sub beam is followed by a short (short) heating by the main beam can take place.

(Example) An embodiment of the present invention will be explained below with reference to FIG.

In the figure, 1 is a laser oscillator, and on the laser optical axis 3 of the laser beam 2 which is the output light, a plane mirror-shaped beam splitter 4 with a transmittance of 10% and a plane mirror-shaped pend mirror 5 are arranged. It is. 6 is a condensing lens for condensing the main beam 7 taken out by the beam splitter 4, and 8 is a condensing lens for condensing the sub beam 9 totally reflected by the pendulum mirror 5.

In the above device, approximately 90% of the laser power of the laser beam 2 from the laser emitting device 111 is reflected by the beam splitter 4 to form the main beam 7, and the main beam 7 is condensed into the required size by the condensing lens 6. Then, as the beam spot 10, the outer peripheral surface of the approximately disk-shaped heated object 11 (heated blood)
Irradiate to 12.

The sub-beam 9 that has passed through the beam splitter 4 has about 10% of the laser power of the laser beam 2, and is totally reflected by the pend mirror 5 and condensed into a necessary size by the condensing lens 8. Beam spot 1 on 12
3, a position near the beam spot 10 is irradiated. On the outer circumferential surface 12 of the object to be heated 11, hard metal powder is supplied as a metal layer by scattering or other known method as shown by arrow The main beam 7 is rotated from the preheating side to the heating side as shown in FIG. Perform heating of the preheated area (main heating). As a result, the hard metal on the outer circumferential surface 12 is melted to form a thin metal layer, so the main beam 7 and the sub beam 9 continue to be irradiated, and the heated object 11 is rotated once to form a metal layer around the entire circumference. Once formed, heating of one object to be heated 11 is completed. In the above process, the timing of the start and end of irradiation of the main beam 7 and the sub-beam 9 can be adjusted by using a shutter (not shown) provided in the optical path of each beam, but it is possible to adjust the timing of the start and end of irradiation of the main beam 7 and the sub-beam 9. In some cases, the irradiation of both beams may start and end at the same time.

The present invention is not limited to the above-mentioned embodiments. For example, a beam extracted by a beam splitter 4 with a high transmittance may be used as a sub beam, or a beam that passes through the beam splitter 4 and travels straight can be used as a sub beam. Condensing the light and heating or preheating the object to be heated on the laser optical axis 3,
The beam taken out by the beam splitter 4 may be totally reflected by a pendor mirror and used for preheating or heating.

It is also possible to increase the number of beam splitters 4 to obtain two or more sub beams for preheating.

Further, in the above embodiment, a flat beam splitter and pend mirror are used, but if a concave mirror beam splitter and pend mirror are used, the condensing lens can be omitted, and the apparatus can be simplified considerably. Further, in the above embodiment, the heated object 11 is rotated because the outer circumferential surface 12, which is the heated blood, is circular, but if the heated blood is flat, the heated object may be moved linearly.

The above description has been made of the case where the present invention is applied to heating in a metal-plating process, but this invention can also be applied to various types of laser processing such as heat treatment and melting of materials in addition to metal-plating.

(Effects of the Invention) As explained above, according to the present invention, the object to be heated can be preheated and heated by one laser oscillator, and no other heat source is required, so the device is simple and economical. It is. In addition, the sub-beam allows local preheating of only the necessary areas, and heating can be performed subsequent to preheating.
Energy saving can be achieved with less energy loss. In addition, it is easy to adjust the distribution of heating energy 1d between the main beam and the sub-beam, and by adding adjustment of the beam spot size of each beam as necessary, it is possible to adjust the distribution of heating energy 1d by the main beam and sub-beams. Laser processing can be performed under optimal heating conditions.

[Brief explanation of drawings]

FIG. 1 is an equipment system diagram of a heating device showing one embodiment of the present invention. 1... Laser oscillator, 2... Laser beam, 4
...beam splitter-15...pend mirror, 6
... Condensing lens, 7... Main beam, 8... Condensing lens, 9... Sub-beam, 10... Beam sub-box 1-
111... Heated object, 12... Outer peripheral surface (heated surface), 1
3...Beam spot.

Claims (1)

[Claims] The laser beam emitted from the laser oscillator is split into a main beam and a sub beam using a beam splitter.
The main beam and the sub beam are irradiated to a position near the heated surface of the object to be heated, the sub beam preheats the heated surface, and the preheated heated surface is moved to the main beam irradiation section. A heating method using a laser beam, characterized in that heating is performed using the main beam.