JP2719979B2 - Welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of the Invention The present invention relates to a butt welding method for cutting end faces of a thin metal plate such as a thin steel plate.

(2) Conventional technology Welding technology for welding thin metal materials using a high-density heat source of a laser beam is already known (Mechanical Engineering, Vol. 23, Welding Engineering 23, published by Corona Co., Ltd.). ), 23rd
See Chapter “Recent Welding Techniques”.

(3) Problems to be Solved by the Invention In laser welding, since the material to be welded is largely penetrated by laser beam irradiation, predetermined welding conditions exist when butt-welding cut cross sections of thin steel plates. For example, when the thickness of a thin steel plate is 2.0 to 4.0 mm, the welding clearance between the cut end surfaces must be 0.02 mm or less.If the clearance is 0.02 mm or more, the steel plate is irradiated with a laser beam. A depression is formed along the welding line due to the penetration, and the surface accuracy of welding deteriorates.

However, when the thin steel sheet 01 having a thickness of 2.0 to 4.0 mm is actually sheared and cut (precision punching), the cut end face E ′ becomes an uneven surface having a height difference of 0.03 to 0.05 mm as shown in FIG. If the cut end surfaces E 'are butt-butted to each other, the clearance between them becomes 0.06-0.10 mm as shown in FIG. 4, which greatly exceeds the clearance of 0.02 mm or less, which is the laser welding condition described above. As a result, there is a problem that a recessed portion exceeding an allowable range is generated in a welding line, and it cannot be applied to a welding rim such as a wheel for a vehicle that uses the welding surface as it is.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a welding method in which a cut end face of a thin metal sheet such as a thin steel sheet can be welded with high strength without a concave portion on the welding surface and with high accuracy. It is assumed that.

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention butt-cuts the cut end faces of a thin metal plate such as a thin steel plate, and welds the cut end faces to each other by laser welding or electron beam welding. In the welding method, the cut end faces of the metal sheet are crushed to form overlays on both side edges in the thickness direction of each of the cut end faces, and then the corresponding overlay of the cut end faces is formed. The welding is performed by abutting the cut end surfaces of each other so that they are close to each other.

(2) Function When butt-welding cut end surfaces of a thin metal plate such as a thin steel plate, the cut end surfaces are crushed to form overlays on both side edges of each cut end surface in the plate thickness direction. The cut end faces are joined together so that the corresponding overlays are in close contact with each other,
Laser welding or electron beam welding is performed in the butt state. As a result, before welding, a clearance that causes the generation of a concave portion due to the penetration of the steel plate during welding is almost removed at the cut end face abutting portion on the metal sheet surface side. For this reason, at the time of subsequent welding, it is possible to effectively avoid the occurrence of a concave portion along the welding line due to the penetration of the steel sheet and the deterioration of the surface accuracy.

(3) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

First, as shown in FIG. 1 (a), a strip-shaped thin steel plate 1 is prepared by shearing and cutting a coil material having a fixed width of a thin steel plate.

Next FIG. 1 (b) the steel sheet 1 as shown in rounded in a circular shape the cut edge E, the end portion 1 ₁ comprising E, 1 ₁ the cutting edge in the flat E, butt E together And CO ₂ them
The annular blank 2 is made by laser welding.

Next, the annular blank 2 is appropriately machined to produce a wheel rim 3 of a wheel.

In this case, the welded portion is utilized without any post-processing.

 Incidentally, the above-described welding process is performed as follows.

The cut end surfaces E, E of the thin steel plate 1 are subjected to end surface processing prior to CO ₂ laser welding.

(I) After clamp from upper and lower surfaces near the clamper 4 of FIG. 2 cut end surface of the steel sheet 1 as shown in (A) E, to the cutting end face E, the projections 5 ₁ in the central portion of the outer peripheral surface The outer peripheral surface of the drum-shaped roller 5 is
When the cutting end face E is pressed in the longitudinal direction of the thin steel plate 1, that is, in the butting direction while pressing the cutting end face E with the center of the outer peripheral surface of the roller 5, the end face E is crushed and The thickness direction (that is, the thickness direction of the thin steel plate 1 → second)
Overlays 6, 6 are formed on both side edges (in the vertical direction in the figure), and at the same time, the cut end surface is smoothly finished by the rollers 5.

(Ii) Then, the cut end faces processed as described above are butted as shown in FIG. 2 (B) so that the corresponding overlays 6, 6 of the cut end faces are brought into close contact with each other.

(Iii) After the end portions 11 ₁ , 11 ₁ of the thin steel plate 1 are clamped by the clamper 7, the cut end surfaces E, E joined to each other are CO _2.
It is welded by a laser beam from a laser welding machine 8.

At this time, the recess formed in the welding line by laser welding is filled with the overlay 6. And it is possible to perform butt welding with strong and good surface accuracy.

In the above embodiment, the case where the method of the present invention is applied to CO ₂ laser welding is described.However, the present invention can be applied to micro laser welding or electron beam welding, and the method of the present invention can perform the above-described welding. It can also be applied to welding of cut end faces of other thin metal sheets.

Further, in the above-described embodiment, the case where a roller is used as a means for forming a cladding on the cut end face of a thin steel plate has been described, but it is a matter of course that this cladding may be performed by other means.

Further, in the above embodiment, both cut end faces of one thin plate are welded, but cut end faces of two thin plates may be welded.

C. Effects of the Invention As described above, according to the present invention, when butt-welding the cut end surfaces of a thin metal plate such as a thin steel plate, the cut end surfaces are crushed to crush the cut end surfaces on both sides in the plate thickness direction. After forming the overlay on the edge, the cut end faces are joined together so that the corresponding overlays are in close contact with each other, and laser welding or electron beam welding is performed in the abutted state. At the cut end butting part on the thin plate surface side,
There is hardly any clearance that causes the formation of recesses when the steel plate melts during welding.Therefore, it is possible to avoid the occurrence of recesses along the welding line due to the penetration of the steel plate during welding, so that the strength and surface accuracy are good. Butt welding can be performed, which is particularly advantageous when the welding line is exposed on the product surface.

[Brief description of the drawings]

FIGS. 1 (a), 1 (b), and 3 (c) are process diagrams showing steps of manufacturing a wheel rim from a thin steel plate, and FIGS.
(B) and (C) are process drawings showing a welding process according to the welding method of the present invention, FIG. 3 is a cross-sectional view of a shearing cut end face of a thin steel plate, and FIG. 4 is a cross-sectional view of the cut end face butted. . 1 ... thin steel plate, 6 ... overlay, E ... cut end face

Claims (1)

(57) [Claims] 1. A welding method in which cut end faces of a thin metal plate such as a thin steel plate are butted and laser cut or electron beam welded to both cut end faces, wherein the cut end face of the thin metal plate is crushed, A weld is formed on each side edge in the thickness direction of each cut end face, and then the cut end faces are butted against each other so that the corresponding overlays of the cut end faces come into close contact with each other, and the welding is performed. Characteristic welding method.