JPH0320058Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a joining structure for joining parts in welding using a laser beam.

[Conventional technology]

Conventionally, as shown in Figure 2, the joint and its surroundings were welded at the same height.

[Problem that the invention attempts to solve]

However, conventional laser bonded structures have the disadvantage that the cross-sectional shape of the joint is concave, and cohesive stress is concentrated in the center of the concave area, which can lead to cracks and further cracks due to the presence of segregation of low melting point components. Ta.

Therefore, in order to solve these conventional drawbacks, this invention was developed to prevent the cross-sectional shape of the joint from becoming concave under any conditions, and to eliminate the segregation of low melting point components (such as MnS compounds) for the purpose of adding free machinability. The aim is to obtain a crack-free bond even when the

[Means for solving problems]

In order to solve the above problem, the present invention provides a structure in which parts to be laser welded are provided with a portion parallel to the welding direction and lower than the joint, thereby preventing cracks from occurring at the joint.

[Effect]

When the joints of the above structures are joined using a laser beam, even if the molten metal fills the gap, the excess metal will coagulate and solidify on the gap, resulting in a convex shape, avoiding stress concentration, and preventing cracks. A joint is obtained. In addition, according to the present invention, the stress caused by contraction when the molten metal solidifies due to laser beam irradiation can be alleviated by the narrow convex joint.

〔Example〕

Examples of this invention will be described below based on the drawings. In FIG. 1, parts 1 and 2 have a portion 4 lower than the joining portion 3 provided parallel to the joining direction 5. (In this example, A: 0.4mm, B: 0.2mm
). With such a structure, when melted and bonded using a laser beam, as shown in FIG. 3, the bonded portion 6 melts and partially fills the gap, and the remainder solidifies into a convex shape 7 thereon. In FIG. 4, the component 8 is at the same height as the joint 9, and the component 10 has a portion 11 lower than the joint 9 provided parallel to the joining direction 12. (In this example, A: 0.15 mm and B: 0.1 mm). In this structure as well, as shown in FIG. 5, the joint portion 13 melts and the remaining portion fills the gap and solidifies in the form of the upper half convex shape 14.

In this way, even if there is a portion 11 lower than the joint 9 on one of the parts, stress concentration can be avoided and a crack-free joint can be obtained.

[Effect of idea]

As explained above, this invention has the effect that by providing a portion lower than the laser joint, a stable joint without cracks can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a laser joint structure according to the present invention, FIG. 2 is a perspective view of a conventional laser joint structure, and FIG. 3 is a perspective view of the structure shown in FIG. 1 after joining. FIG. 4 is a perspective view of another laser joint structure according to the present invention, and FIG. 5 is a perspective view of the structure shown in FIG. 4 after being joined. 1... Part, 2... Part, 3... Joint, 4...
...lower part, 5...joining direction.

Claims (1)

[Scope of utility model registration request] In two or more parts to be laser welded, a part lower than the joint part is provided outside the joint part, parallel to the joining direction, on one or more of the parts to be joined, and the joining part of the joint part after joining is A laser bonding structure characterized by having a solidified convex shape.