JPS61169184A - Laser welding method of butt joint - Google Patents

Abstract

PURPOSE:To improve the tolerance in the positional deviation of a laser beam by working a single Vee groove along the weld line of a butt joint then irradiating the laser beam along the groove thereby welding the joint. CONSTITUTION:The angle parts of joint surfaces 110 of joints 10A, 10B are machined in a diagonal direction to form the single Vee groove 120. The laser beam 200 is irradiated along the groove 120 to form a penetration part 12 having an approximately elliptical section by laser beam welding. The empirically ascertained results indicate that the part 12 is always formed to the elliptical shape as far as the beam 200 is irradiated within the groove 120 in spite of the deviation of the irradiation position from the weld line 100. the joints 10A, 10B are therefore surely welded to the inside. The tolerance in the positional deviation of the laser beam 200 is improved by the above-mentioned method.

Description

[Detailed description of the invention] Industrial application field 1 The present invention relates to improvements in a method for laser welding butt joints.

[Prior Art] A laser welding method in which welding is performed using a laser beam has been well known, and this welding method has a high energy concentration of the laser beam amount J' and can perform welding with a narrow heat-affected zone. Furthermore, since the laser is a light beam, it has excellent features such as being able to weld through transparent materials, so it is widely used for welding various joints.

FIG. 3 shows an example of a laser welding device for laser welding a pair of butt joints 10A and 10B along a welding line 100, and this laser welding device uses a laser oscillator that generates a laser beam 200. 20, and a reflecting mirror 22 that reflects the laser beam 200 emitted from the laser oscillator 2o and sets its direction. The focus is adjusted to focus near 10, and then the joint 10 is irradiated via the nozzle 26.

Therefore, as shown in FIG. 4 (A>), the laser beam 20
0 to a pair of butt joints 10A, IOB joining line 10
As shown in FIG. 4(B), a welded portion 12 is formed along this welding line 100 by irradiating the laser beam onto the welding line 100, and both joints 10A and 10B can be successfully laser welded.

[Problems to be Solved by the Invention] Conventional Problems By the way, the predicate portion 12 formed on the joint surface 110 of the inner joint 10A and IOB by the conventional laser welding method is wide on the surface side. The joint 10 has a T-shaped cross section whose width becomes narrower as it goes inside.

Therefore, in the conventional laser welding method, the laser beam 20
The displacement tolerance of the target position with respect to the welding line 100 of 0 is extremely small, for example, as shown in FIG.
Aim position U of laser beam 200 with respect to welding line 100
If the predicate portion 12 is slightly shifted, the predicate portion 12 will be formed as shown in Fig. 5(B), and the inner joints 10△, 10B will be welded only on their surface portions, but not on the inside, resulting in a welding failure. There were drawbacks.

In addition, in this conventional one-nose welding method, the predicate portion 12 formed by laser welding has a large excess on its surface (that is, it does not protrude outward from the surfaces of the joints 10A and 10B). -There is a risk that the protruding portion of the predicate portion 12 and other parts may mechanically interfere with each other if the joints 10A and 10B are 91 digits in contact with other parts after welding is completed. There was a problem.

Furthermore, in such conventional sea 1F welding method (because the surface area of the J1 welding part 12 is large, a large amount of spatter is generated during laser welding, and an effective countermeasure is desired.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to eliminate the positional deviation i' of the laser beam from the welding target position (with a high degree of tolerance and to ensure good welding of joints). The object of the present invention is to provide a laser welding method for a butt joint that can be performed.

[Means and effects for solving the problems] In order to achieve the above object, the method of the present invention forms a V-shaped groove along the welding line of a pair of butt joints, and It is characterized by irradiating the Ray IJ'' beam along the leading vortex and welding the inner joint to sea 11.

By Jing in this manner, a predicate portion is formed on the joint surface of the inner joint and is narrow on the surface side and wide on the inside thereof, and the inner joint is welded.

In the present invention, the predicate portion having such a shape can be formed by irradiating a laser beam with a sufficient width to any position of the V-shaped groove. Compared to the welding method, the tolerance for positional deviation from the welding target position of the Rede beam is very large, so even if the laser beam irradiation position deviates slightly from the welding line, the deviation is within the range of the V-shaped groove volume. It becomes possible to reliably laser weld the joint.

Furthermore, according to the laser welding method of the present invention, since the predicate portion to be formed is narrow at its surface portion, this portion does not protrude from the joint surface, and furthermore, the surface of this reservoir portion is narrow. Since it is formed in a V-shaped groove, there is no fear that the reservoir surface will protrude from the joint surface and cause physical interference with other assembled groove members, as in conventional laser welding.

Furthermore, if the laser welding method of the present invention is used, the surface of the welded part becomes narrower and its surface area becomes smaller, making it possible to reduce the amount of spatter generated during laser welding.

[Example] Next, a preferred example of the laser welding method according to the present invention will be described based on the drawings. Incidentally, members corresponding to those of the conventional example shown in FIGS. 4 and 5 are given the same reference numerals, and their explanations will be omitted.

FIG. 1 shows a preferred embodiment of the present invention, and a characteristic feature of the present invention is that a V-shaped groove 120 is formed along a weld line 1oO of a pair of butt joints to be phase welded. , the laser beam 200 is aimed along the iMl 20 to laser weld the inner joints 10A and 10B.

In the embodiment, the V-shaped groove 120 is formed in each joint 10.
The corners of the joint surfaces 110 of Δ and 10B are formed by cutting diagonally into a symmetrical shape, and the inner joints 10A and 10B thus formed are shown in FIG. 1 (A>). It is formed by impregnation at step 110.

And, formed in this way, lζ V-shaped space is 120 m
J2 was cured and decided to shine a laser beam of 200 on IJ-J.
As shown in FIG. 1 (F3), between the inner joints 10Δ and 10B, there is a predicate portion 12 having a substantially oval cross section that is narrow on the surface side and increases in width toward the inside.
will be formed.

According to experiments, the predicate portion 12 having such an oval cross-section has the ability to maintain V even if the irradiation position circle of the sea 1F beam 200 deviates from the welding line 100, as shown in FIG. 2 (△), for example. It is always formed within the intermittent groove 120, and both joints 10A,
10B can be reliably welded to the inside with 1+J capacity.
It has been confirmed that there is.

According to the laser welding method of the present invention, by irradiating the rake beam 200 along the V-shaped light leak 120, both joints 10A and 10B can be reliably laser welded to the inside thereof. It is understood that, compared to the conventional laser welding method described above, the tolerance for deviation of the position of the rake beam 200 relative to the welding target position is increased by one minute, and reliable welding is possible. Furthermore, according to the method of the present invention, the width of the predicate portion 12 to be formed is narrow (J), and since the predicate portion 12 is formed within the V-shaped groove 120,
The surface of the predicate portion 12 does not protrude from the surface of the joints 10A, 10B and cause physical interference with other members.

Furthermore, according to the radar welding method of the present invention, the surface area of the predicate portion 12 is extremely small compared to conventional welding methods, so that the flow of spatter generated during laser welding can be suppressed to 1 minute. This makes it possible to perform good welding.

[Effects of the Invention] As explained above, according to the present invention, there is a high tolerance for positional deviation in the welding line between the laser beam irradiation gaps, and moreover, the spatter generated during welding of the welding lines can be reduced. In addition, there is no possibility of forming a protrusion in the welded part that causes physical interference with other assembled members.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams showing a preferred embodiment of the sea 1 f' welding method according to the present invention; FIG. 3 is an explanatory diagram showing an example of a laser beam generator for welding; 1 and 5 are explanatory diagrams of the conventional Rede welding method 1). 10A, IOB ... Joint 100 ... Welding line 110 ... Joint surface 120 ... V-shaped groove 200 ... Laser beam \. Applicant Toyota Motor Corporation Ne1 Agent Patent attorney Kenji Shimita (7-36) (1 other person) Figure 1 (A) CB) Figure 2 (A) (B) Lower Figure 3 1tJA ILJLj Figure 4 (A) (B) Figure 5 (A) (B) 4 and 114!

Claims (1)

[Claims] (1) A butt joint characterized in that a V-shaped groove is formed along the welding line of a pair of butt joints, and a laser beam is irradiated along the V-shaped groove to laser weld both joints. Laser welding method.