JPS59159287A - Laser working device - Google Patents

Abstract

PURPOSE:To decrease generation of splashes and to perform adequate laser working with deep penetration by disposing two pieces of condenser lenses on the optical path for laser light, and irradiating the condensing spot on a work. CONSTITUTION:The 1st condenser lens 10 is disposed on a laser oscillator 11 side on the optical path of laser light L which is released from a laser oscillator 11 and is advanced perpendicularly by a reflection mirror 12. The 2nd condenser lens 13 is disposed on the work 14 side coaxially with the lens 10 apart at a specified distance therefrom. Since the light L is once condensed by the lens 10, the incident angle on the surface of the lens 13 increases and an aberration is much larger than in the prior art. The preferable weld zone having a small dent with respect to the deep penetration is thus obtd.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a laser processing device.

[Technical background of the invention and its problems]

Generally, when all processing such as welding, cutting, and drilling is performed using laser light, a laser projector (not shown) is used as shown in Figure 1.
A condenser lens (1
) is provided to irradiate a focused spot onto the workpiece (2).

By the way, the welding process is not performed using the above conventional equipment.
□If the focus position and the amount of removal before and after it (J-)
and second. Depth of dent (Ds) of welded part (3) after therapeutic welding shown in the figure.

The melting, penetration depth, drilling DJl, and spacing are as shown in Figure 3. That is, 1. The horizontal axis indicates the defocus amount (→) in the ←＞, , ←) direction.

As is clear from Fig. 3, where the vertical axis shows both depths Dl) and (D2), the melt penetration depth D2) is 3 mm (Q
The depth of the recess is approximately ↓, approximately 3m.
, it becomes unsuitable for welding. Therefore, in the past, as the melt penetration and depth increased, the occurrence of splash was significant.

,〔invention,? Purpose) The purpose is to provide an apparatus that can reduce the occurrence of splash and suitably perform laser processing with a deep weld penetration depth.
.

[,Invention,Invention 9,Summary,Summary],,,.

-The optical path of the laser oscillation, the laser light emitted from the vessel,
, 2. A plurality of condensing lenses are arranged to irradiate a condensed spot onto the workpiece. This is what I accomplished:
be. ,,,,,.

[Invention, implementation, example]

As shown in Figure 4, the inventors investigated the power density distribution on the surface of the workpiece (2) of the condensed beam transmitted through the condensing lens and the machining characteristics, and found that the peak values in the power dense layer distribution were the same. Then, the spots with a wide distribution at the base (4
) was found to produce less tin rush than spot (5) with a narrow distribution. Furthermore, we have found that increasing the aberration difference in the condensing optical system is effective as a means to obtain a wide distribution of tails.

Based on the above background, the fifth embodiment of the present invention has been developed.
This will be explained based on the diagram. 10) is a first condenser lens disposed on the laser oscillator αυ side on the optical path of the laser beam (L) emitted from the laser oscillator αD and traveling in the vertical direction via the reflecting mirror (121). (13) is a second condenser lens located on the side of the workpiece I and disposed coaxially with the first condenser lens (10) at a constant distance.

By the way, in FIG. 5, the distance from the condensing point of the first condensing lens 00) to the axial center of the second condensing lens (13) is a, and from this axial center to the second condensing lens (13) (b) and the focal length of the second condensing lens (13) is (f), then 1/a + 17t) = 1/f
(7) Be in a relationship. Here, the first condensing lens (10)
The diameter of the spont is (dI), and the diameter of the second condenser lens (1□□□
If the focused spot diameter of is (d2), then d2-bxdI
/a, that is, d, = fXd, /af, and in order to condense the light with the second condensing lens (13), the distance (a)
must be longer than the focal length f of the second condenser lens (lj. Therefore, the first condenser lens 00
Both lenses 10) and u3) are arranged so that the image of the laser beam (L) focused by ) at the focal position of the first focusing lens is formed and focused by the second focusing lens 03). be done.

According to the above configuration, since the laser beam (L) is once condensed by the first condenser lens (10), the incident angle on the surface of the second condenser lens ([3) is small. As a result, the aberration becomes extremely large compared to the conventional one. Furthermore, when the welding results according to this configuration are shown in the same way as FIG. 3 showing the results according to the above-mentioned prior art, the result is shown in FIG. 6. From this figure, it can be seen that the depth of the recess (a) is much smaller than in the past, and the occurrence of splashes is greatly reduced.

〔Effect of the invention〕

As described in detail above, by using a simple configuration in which two condensing lenses are arranged on the laser optical path, it is possible to obtain a preferable welded part with a small depression in spite of the deep welding process, for example, in welding processing. Based on the allowable depth of the depression, this means that it is possible to obtain deep weld penetration with less energy than in the past. Therefore, since there is no need to forcefully increase the energy, pulse YAG
In the case of a laser, the effect of lengthening the life of the excitation lamp can also be obtained.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing a conventional example, Figure 2 is a sectional view showing the state of a welded part, and Figure 3 is a welded part when welding is carried out using conventional equipment. FIG. 4 is an energy density distribution diagram for explaining the present invention in detail, FIG. 5 is a configuration diagram showing an embodiment of the present invention, and FIG. 6 is a diagram showing the relationship between FIG. 3 is a diagram showing the relationship between the depths of both the depth of the weld and the depth of the weld and the amount of defocus when the present invention is applied to welding. 00...First condensing lens Uυ...Laser oscillator Uri...Reflector θ (support)...Second condensing lens Agent Patent attorney Noriyuki Chika (and one other person)

Claims (2)

[Claims] (1) A laser emitter, a first condenser lens that condenses the laser beam emitted from the laser emitter, and a first condenser lens that condenses the laser beam that has just passed through the first condenser lens. A laser processing device comprising a second condensing lens. (2) The laser processing apparatus according to claim 1, wherein the second condenser lens is arranged behind the focal point position of the first condenser lens.