JPS5837074B2 - Laser welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a laser welding force method in which welding is performed using a laser beam.

Generally, when welding a pair of members to be welded using a laser beam, the laser beam from a laser oscillator is focused by a condenser lens and irradiated onto the joint portion of the members to be welded.

In such a welding process, the strength of the welded portion is better as the weld depth and area are greater.

By the way, the energy density distribution state in the spot of the laser beam is almost a normal distribution state with the maximum at the center of the spot. The area corresponding to the center area is rapidly heated, and the area corresponding to the periphery of the spot has a very slow temperature rise, making it impossible to obtain a uniform temperature distribution.

Therefore, the parts to be welded in the parts that are rapidly heated will evaporate or scatter, forming a depression in the welded part, and the parts where the temperature rises poorly will not melt, and the smaller the weld area, the better the strength. It was not possible to perform welding.

This invention has been made based on the above circumstances, and its purpose is to cause a laser beam that irradiates the vicinity of the joint of a pair of welded members to scan in a direction transverse to the joining line of the welded members. Accordingly, it is an object of the present invention to provide a laser welding method that melts the joint portion of a member to be welded without rapidly heating locally, and enables welding with good strength.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, 1 is a laser oscillator that emits, for example, a pulsed laser beam, and a laser beam L emitted from this laser oscillator 1 is focused by an optical system 2 such as a convex lens.

The spot of this laser beam L irradiates the joint portion of a pair of members to be welded 4 and 5 placed on a table 3 which can be driven in a plane by a mechanism not shown.

Further, the optical system 2 is connected to an operating body 8 of a vibration generator T to which a clock oscillator 6 is connected.

The clock oscillator 6 generates, for example, a sine wave, and causes the operating body 8 of the vibration generator 7 to reciprocate in a direction perpendicular to the optical axis of the laser beam L.

Further, a synchronization controller 9 is connected to the clock oscillator 6, and this synchronization controller G4 9 controls the oscillation of the laser oscillator 1 in synchronization with the sine wave generated by the clock oscillator 6.

Next, the operation of the above structure will be explained.

First, the table 3 is operated manually or the like to align the spot center of the laser beam L with the joining line of the members 4 and 5 to be welded.

Thereafter, when a signal is input to the clock oscillator 6, the actuating body 8 of the vibration generator 7 vibrates in a sine wave, and the optical system 2 has its optical center aligned with the parts 4 and 5 to be welded, as shown in FIG. It vibrates back and forth in the range of ±X with the joining line of as the center O.

The signal from the clock oscillator 6 is also input to the synchronous controller 9.

This synchronous controller 9 is configured so that the members to be welded 4 and 5 are
A signal is output to the laser oscillator 1 while moving from +X1 to -Xl shown in FIG.

At this time, the spot of the laser beam L is on the workpiece 4 to be welded.
.

Therefore, the joining part of the members to be welded 4 and 5? The energy density distribution state thus obtained is the summation value of the energy distribution state of the scanning spot.

That is, as shown in FIG. 3, the energy density of the members 4 and 5 to be welded is uniformly increased within a range of ±x1 centering on the joining line, so that the joined parts are melted widely and deeply and welded.

Therefore, local parts of the members 4, 5 to be welded are not heated rapidly, so that the members 4, 5 do not evaporate or scatter, and welding with good strength can be performed.

In the above example, the optical system was vibrated by a vibration generator, but the force of the welded members may also be vibrated, and the point is that the laser beam spot crosses the joining line of the pair of welded members. All you have to do is scan.

Furthermore, the laser beam is not limited to one that is oscillated in a pulsed manner, and may be one that is continuously oscillated.

As described above, in the present invention, a laser beam is focused by an optical system, and the vicinity of the joint of a pair of members to be welded is irradiated, and the laser beam is scanned in a direction crossing the joining line of the members to be welded. Therefore, the joint parts of the parts to be welded are welded wide and deeply, and the parts to be welded can be welded with high strength because there is no sudden local heating that evaporates or scatters the parts as in the conventional method. be able to.

Furthermore, since the laser beam scans in a direction that crosses the joining line between the pair of workpieces, welding can be performed satisfactorily without the need for highly accurate alignment between the joining line and the center of the laser beam spot. Therefore, various effects such as improved work efficiency can be achieved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a schematic diagram of the structure, FIG. 2 is an explanatory diagram showing the relationship between the vibration of the welded member and the oscillation state of the laser beam, and FIG. 3 FIG. 2 is an explanatory diagram showing a distribution state of energy density in a member to be welded. 1... Laser oscillator, 2... Optical system,
4, 5... Part to be welded, L... Laser beam.

Claims (1)

[Claims] 1 A laser beam emitted from a laser oscillator is focused by an optical system to irradiate the vicinity of the joint of a pair of welded members, and the laser beam is scanned in a direction across the joining line of the welded members. Laser welding force method.