JPS5939491A - Laser welding method of thin metallic sheet - Google Patents

Abstract

PURPOSE:To subject thin metallic sheets to laser welding with a simple installation and stage at a suitable depth, by superposing the thin metallic sheets, irradiating a laser beam thereto to provide a deep penetration with a spot of a small diameter then causing a shallow penetration with a spot of a large diameter. CONSTITUTION:The position of a lens 5 for restricting laser light is adjusted with respect to thin metallic sheets 1, 2 which are superposed on each other. The 1st pulse of the initial laser light irradiates a weld zone 3 with the beam having a small spot diameter and a large penetration depth. The lens 5 is then moved upward with the support barrel 6 thereof by means of a pulse motor 7 so that the beam of the 2nd pulse having a large diameter and a small penetration depth is applied on the weld zone 3, thereby welding the sheets 1, 2. There is no need for modification of the laser oscillator and fore-stages such as drilling or the like in this stage. Smaller peak power is required and burring on the surface arises less.

Description

[Detailed description of the invention] The present invention relates to a method for laser welding thin metal plates.

Conventionally, the following method has been adopted for welding a gold maple plate, which is a thin metal plate (thickness 0.5 ym+) and whose end face cannot be welded.

FIG. 1 shows a case where a thin metal plate 1.2 is welded with a laser beam, and 3 indicates a bath welding part. (If Ino is normal,
(B) is too complex, and (C) is insufficiently complex. In this method, the bath contact depth t is lower than shown in the figure.
It is difficult to always control the position in one step, and there is also a drawback that overlapping occurs in M1s outside the spot.

FIG. 2 shows another method, in which four holes are drilled in advance in the thin metal plate 1 as shown in FIG. In this method, the pilot hole drilling work is safe.

The present invention aims to improve the above-mentioned drawbacks and provide a laser welding method that does not cause over-penetration or insufficient weld-penetration and does not require drilling.

Next, the present invention will be explained with reference to the accompanying drawings.

In Fig. 3, 1 and 2 are Kanasu thin plates, 5 is a lens for focusing the laser beam, 6 is a support tube for the lens X5, and 7 is a pulse motor used to move the support tube 6 in the vertical direction. to snatch

Next, to explain the operation, in Fig. 17, P1 adjusts t11t at the position of lens 5, and the first pulse of the first Q laser beam has a small spot diameter and a depth of penetration. Next, as shown in the figure (b), the focusing lens 5 is moved upward by the pulse motor 7.Next, in this state, the second pulse has a large diameter and a small welding depth. The beam r is applied to a gold J% thin plate to be processed.In this case, the output power of both the first and second pulses may be the same.

In the present invention, the first pulse has a small spot diameter, and the welding;
) - A laser beam with a large depth is irradiated, and then the second pulse is a laser beam with a large spot diameter and a small penetration depth. Since this is done using Kesoft processing, there is no need to modify the oscillator for laser light at all.

(b) Since row 9 is processed using only laser light, the entire M+J process (drilling) is not required.

(Since it is a 152-step melting method, the peak power is smaller than that of simultaneous melting, and the model capacity can be increased by one rank.

(b) The second pulse has a small penetration depth, so the occurrence of surface cracks is small.

It has the following effects.

The present invention can also be widely used for (a) drilling holes in metal plates that do not require any red spots, and Φ) drilling holes using a processing machine with insufficient power for the workpiece.

[Brief explanation of drawings]

Figure 1 (a), (b), re and Figure 2 (ino, (b))
Figure 3 shows the entire conventional welding method, and Figure 3 shows an embodiment of the welding method of the present invention. welded part,
5... Lens, 6... Lens support f
fh, 7...Pulse motor Figure 1 (A) (A) Figure 3 (A) (B) (C) (B) (C)

Claims (1)

[Claims] The first pulse irradiates the stacked metal thin plates with a laser beam with a small spot diameter and a large melt penetration depth, and the second pulse irradiates the laser beam with a large spot diameter and a large melt penetration depth. A method for laser welding thin metal plates, characterized by irradiating a laser beam with a small penetration depth.