JP6899253B2 - Laser welding method - Google Patents

Description

In the present invention, the end face of one thin plate-shaped work and the end face of the other thin plate-shaped work are welded by, for example, a laser welding method in which the end faces of the other thin plate-shaped work are abutted at a right angle and laser welding is performed, and the above laser welding method. Regarding welded structures. More specifically, the present invention relates to a laser welding method and a welded structure in which the surface of a welded portion between one work and the other work is formed in an R shape and the back surface of the welded portion is not melted.

Conventionally, metal plates may be butted against each other for laser welding (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-218497

Patent Document 1 describes a configuration in which a thick metal plate and a thin metal plate are butted against each other for laser welding. By the way, when laser welding is performed by butt-welding thin metal plate workpieces, as shown in FIG. 1 (a), a butt joint in which the end faces of the workpieces W are butt-welded and laser welded is performed, as shown in FIG. 1 (b). There is a helicopter joint or the like that performs laser welding of the end faces on which the workpieces W are overlapped. Further, the T-shaped through joint shown in FIG. 1 (c), the T-shaped fillet joint shown in FIG. 1 (d), the lap joint shown in FIG. 1 (e), the lap fillet joint shown in FIG. 1 (f), and the figure. There are various joints such as the L-shaped joint shown in 1 (g) and the L-shaped fillet joint shown in FIG. 1 (h).

Here, when the workpiece is welded to form a box body, the L-shaped joint and the L-shaped fillet joint shown in FIGS. 1 (g) and 1 (h) can be adopted as the joint. However, in the configurations shown in FIGS. 1 (g) and 1 (h), sharp edges of the work remain, which is not preferable.

Therefore, when the work is cut in the unfolded state and bent to match the end faces of the work, the end faces of the work W intersect at right angles as shown in FIG. 1 (i). In this case, overlay welding is performed on the triangular portion between the end faces of the work W. If the work is thin, the work may melt off or a step may be formed between the built-up portion and the work surface. That is, laser welding with a good appearance is difficult.

In the present invention is a laser welding method for performing laser welding is butt in a state of crossing the end face and the other end face of the plate-shaped workpiece hand plate workpiece, the end of one of the workpieces and performing chamfering the surface, the other end face of the fit-out collision on the rear surface of the one of the workpiece of the workpiece, the step of said one end face of the workpiece and said other surface of the workpiece is positioned so as to coincide substantially When the step of melting the abutting portion to be irradiated with laser light metal before SL and one of the workpiece and the other workpiece by the surface tension of the previous SL metal melt, wherein the one of the workpiece and the other workpiece This is a laser welding method including a step of forming the surface of the welded portion into an R shape.

In the above laser welding method, the back surface of the other work is abutted against the back surface of the one work by abutting the back surface of the one work and the back surface of the other work at right angles. ..

In the above laser welding method, the irradiation direction of the laser beam is directed to the vicinity of the one end face of the workpiece, and in a direction oriented near intersection of the rear surface of the rear surface and the other of the workpiece in the one workpiece is there

In the above laser welding method, the pre-Symbol chamfering is performed in 53% to 67% of the depth of the thickness of the one workpiece.

In the above laser welding method, it does not melt the metal in the intersection of the rear surface of the front SL one workpiece and the back surface of the other workpiece.

According to the present invention, the end faces of the workpieces can be easily positioned by abutting against each other, and the surface of the welded portion is formed in an R shape. That is, it can be welded without sharp edges, the safety is improved, and the appearance is good.

It is explanatory drawing which shows the structure of various joints at the time of laser welding a plate material. It is explanatory drawing which performs laser welding by abutting plate-shaped workpieces at right angles. It is explanatory drawing of the laser welding method which concerns on embodiment of this invention. It is explanatory drawing of the welding result by the laser welding method by embodiment of this invention. It is explanatory drawing of the welding result by the laser welding method by embodiment of this invention.

As described above, for example, when a thin plate-shaped work of about 1 mm to 2.5 mm is cut in an unfolded state and then bent, the work is formed as shown in FIG. 1 (i). A triangular space is created between the abutted end faces. This triangular part needs to be built-up welded.

Therefore, as shown in FIG. 2A, one work W1 and the other work W2 are held at right angles by a jig or the like (not shown), and the end portion of one work W1 is held by the other work W2. It was positioned so as to be overlapped on the end face F2. In this case, the position of the end surface F1 of one work W1 is positioned so as to be a position of about 1 / 2t of the plate thickness t of the other work W2. Then, the focal position F is set to the outside (+ position) of the end faces F1 and F2, and the laser beam is in a state including the corners on the surfaces W1A and W2A of the workpieces W1 and W2 and the end faces F1 and F2. LB was irradiated. In this case, the irradiation direction of the laser beam LB was such that the intersection positions C of the back surfaces W1B and W2B of the works W1 and W2 were directed.

When one work W1 and the other work W2 were laser-welded in the state shown in FIG. 2 (a), the welded portion WE of the works W1 and W2 was formed in FIG. 2 due to the surface tension at the time of metal melting. As shown in b), it was confirmed that it was formed in an R shape. Further, in the above laser welding, the intersection positions C of the back surfaces W1B and W2B on the workpieces W1 and W2 were not melted.

That is, when laser welding is performed by abutting the end face F1 of one work W1 and the end face F2 of the other work W2 in a crossed state, the end of the back surface W1B of one work W1 is the end face of the other work W2. by performing laser welding and butt allowed without positioning it over the entire surface of the F2, weld WE without causing burn-is formed in R shape. Then, it was confirmed that the intersecting positions of the back surfaces W1B and W2B on the workpieces W1 and W2 were not melted. That is, it was confirmed that the appearance of the welded portion WE is good and good welding can be performed without melting off.

By the way, as described above, when laser welding is performed by abutting the end portion of one work W1 against the end surface F2 of the other work W2, the position of the end surface F1 in one work W with respect to the end surface F2 of the other work W2. However, even if the laser welding conditions are the same, the shape of the welded portion WE tends to change without becoming a good shape. Further, it is difficult to position the end surface F1 of one work W1 with respect to the end surface F2 of the other work W2.

In view of the above, in the present embodiment, the end portions of the work W1 and the work W2 are butt-welded as follows. That is, as shown in FIGS. 3A and 3B, chamfering CH is performed on the surface at the end of one of the workpieces W1. In this case, as shown in FIG. 3A, a V-shaped groove V is cut around the end of the work W1 with a cutting tool such as a cutting tool. Then, the chamfering CH is performed by performing laser cutting along the bottom of the V-groove.

Then, the end face F2 of the other workpiece W2, Fit can butt on the back W1B of hand work W1. Further, the end surface F1 of one work W1 and the surface W2A of the other work W2 are positioned so as to substantially coincide with each other. That is, the ends of the work W1 and the work W2 are butt-positioned so as to maintain a right angle. This positioning Ru obtained easily performed by using a positioning jig (not shown). As described above, the end surface F1 of one work W1 and the surface W2A of the other work W2 are positioned so as to coincide with each other. Therefore, positional relationship between the one of the workpiece W1 and the other workpiece W2 is that always obtained and positioned to hold a fixed positional relationship.

As described above, after the end of one horizontal or vertical work W1 and the end of the other vertical or horizontal work W2 are butt-positioned at right angles, the butt portion is irradiated with laser light LB to perform laser welding. It is what you do. At this time, the laser beam LB is inclined by an angle θ with respect to the vertical, and the irradiation position of the laser beam LB is an experimentally determined position so that the appearance of the welding position WE is good. is there. That is, as shown in FIGS. 3A and 3B, when chamfering CH is performed on the end of the surface W1A of one of the workpieces W1 and laser welding is performed, as shown in FIG. 3C, The welding position WE is such that the front surface exhibits an R shape due to the surface tension of the molten metal, and the back surfaces of the workpieces W1 and W2 are not melted, resulting in good welding.

By the way, the irradiation direction of the laser beam LB may be a direction in which the vicinity of the end surface F1 of one work W1 is directed and the vicinity of the intersection position between the back surface W1B of one work W1 and the back surface of the other work W2 is directed. desirable.

As described above, when a box body is manufactured as a welded structure by laser welding the right-angled joints of a plurality of workpieces, for example, the appearance of the welded portion at the corner of the box body is an R surface, and the box. Each inner surface of the body intersects at a right angle, and there is no welding bead or the like at the intersection position of each inner surface, resulting in a box body having a good appearance.

By the way, as described above, when one work W1 that has been chamfered at the end is arranged on the upper surface of the other work W2 as shown in FIG. 3 (a) (upper V), FIG. As shown in (b), two types of test pieces were prepared when one work W1 was placed below the other work W2 (lower V). The test piece has SUS304, a plate thickness (t = 1.5 mm), and a welding length of 40 mm. Then, in order to measure the tensile shear force, laser welding was performed under welding conditions in which the back surfaces W1B and W2B of the workpieces W1 and W2 were not melted, and a plurality of test pieces having the same configuration were prepared.

When performing the tensile test, the test was performed by fixing one work W1 with a jig and pulling the other work W2. The results of the test were as shown in FIG. In FIG. 4, the average tensile shear force is an average value of a tensile test using a plurality of test pieces having the same configuration.

In FIG. 4, No. Keru Contact the specimen 1, the depth of the V groove in the workpiece W1 (V-cut amount) is 1.0 mm. In other words, the depth is about 67% of the plate thickness of the work W1. No. The depth of the V groove of the work W1 which is the test piece of 3 and 4 is 0.8 mm, which is about 53% of the plate thickness. No. The depth of the V groove of the work W1 which is the test piece of 5 and 6 is 0.6 mm, which is about 40% of the plate thickness.

As apparent from the results shown in FIG. 4, the depth of the V groove becomes shallower and (small), FIG. 3 (a), that a thicker end faces F1 in one of the work W1 illustrated in (b) .. Therefore, when the V-groove becomes shallow, the amount of molten metal in the welded portion WE increases, and the edge tends to bulge. Therefore, the depth of the V-groove has an appropriate range.

Therefore, at SUS304 and t = 1.5 mm, the difference in the shape of the R surface bead of the welded portion WE between the upper V and the lower V was inspected in more detail, and it was as shown in FIG. As is clear from FIG. 5, when the plate thickness is t = 1.5 mm, the depth of the V groove is preferably 1 mm to 0.8 mm. That is, a range of about 67% to about 53% with respect to the plate thickness of the work W1 is preferable.

The plate material is not limited to SUS, but also includes, for example, SPC and Al. Further, the thin plate material is not limited to t = 1.5 mm, and the V groove can be formed in the range of t = 1.0 mm to t = 2.5 mm (the depth of the V groove is 2.0 mm). it can. Therefore, when V-grooves in the range of about 67% to about 53% of the plate thickness were formed on the workpiece of each plate thickness and the same laser machining as described above was performed, almost the same effect as described above was obtained. Was done.

By the way, as is clear from FIG. 4, even if the depths of the V grooves are the same, the average tensile shear force is larger in the lower V than in the upper V. Therefore, the arrangement relationship between one work W1 and the other work W2 is arranged in the relationship of the lower V as shown in FIG. 3 (b) rather than the relationship of the upper V as shown in FIG. 3 (a). It is desirable to perform laser welding.

W1 One work W2 The other work W1A Front surface W2A Front surface W1B Back surface W2B Back surface F1 End surface F2 End surface C Back surface intersection position WE Welded part

Claims (5)

This is a laser welding method in which laser welding is performed by abutting the end face of one plate-shaped work and the end face of the other plate-shaped work in a crossed state.
And performing chamfering the surface at the end of the one of the workpiece,
A step of positioning such that the other end face of the fit-out collision on the rear surface of the one of the workpiece of the workpiece, the one end face of the workpiece and said other surface of the workpiece substantially aligned,
A step of melting a metal by irradiating a laser beam to the abutting portion of said the one of the workpiece and the other workpiece,
By the surface tension at the metal melt, forming a surface of the welded portion of the the one of the workpiece and the other workpiece in R shape,
Laser welding method including. The laser according to claim 1, wherein the back surface of the one work and the back surface of the other work are butted so as to form a right angle, so that the end surface of the other work is abutted against the back surface of the one work. Welding method. Irradiation direction before Symbol laser beam is directed to the vicinity of the one end face of the workpiece, and claim 1 is a direction directed to the vicinity of intersection of the rear surface of the rear surface and the other of the workpiece in the one workpiece or 2 The laser welding method described in. The pre-Symbol chamfering, laser welding method according to claim 1 carried out in 53% to 67% of the depth of the thickness of the one workpiece. Laser welding method according to claim 1 which does not melt the metal in the intersection of the rear surface of the front SL one of the back and the other workpiece of the workpiece.

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