JP2010240672A - Method for welding thin plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for welding a thin plate by which, when a welding line includes an intersection or a corner for changing welding directions in the middle of the welding line, stress concentration caused by heat shrinkage by welding is prevented in the intersection or the corner, and stress concentration caused by heat shrinkage by welding is also prevented in an end of the welding line in a straight part, and consequently blister starting from such portions is prevented in welding a thin plate. <P>SOLUTION: A circular welding line 7 is formed at a corner 3 present in the middle of the welding line 2 of a thin plate 1 or at an end of the welding line 2 in the straight part 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for welding thin steel materials.

  When the steel material of the thin plate 1 is welded, for example, when the corner portion 3 that is bent at a right angle is present in the middle, the welding line 2 is only the straight portion 4, and as shown in FIG. When the thin plate 1 is abutted and the straight welding line 2 crosses in a cross shape and an intersection point 5 is generated, the straight welding line 2 intersects in a T shape and the intersection point 6 may be generated.

  When the thin plate 1 is welded in this way, since the rigidity of the steel material is small, there is a corner portion in the middle of the welding line 2 or stress concentration due to thermal contraction due to welding at the end of the straight welding line 2. (The direction indicated by the arrow in FIGS. 6 and 7), and a bulge 10 is generated in the thin plate 1 starting from this point.

  In order to prevent this swelling, conventionally, in the construction field, for example, a design in which welding details are taken into consideration is provided by providing scallops so that the welding lines do not overlap at corners or intersections.

  Moreover, in welding thin steel plates such as automobiles and trains, spot welding with reduced welding amount or friction stir welding is performed in order to suppress deformation due to welding.

  The prior art is generally performed by those skilled in the art, and is not related to a known literature invention.

  As for the prior art, as a means for preventing the occurrence of stress concentration due to thermal contraction due to welding in the case where corners are present in the middle of the welding line 2 or at the end of the straight welding line 2, The welding method itself has been changed to a type that does not easily deform, or a design that takes into account welding details, such as the provision of scallops, is necessary. There has been no established means that can be generally adopted.

  The present invention has been made in view of the above circumstances, in the case where there is a corner in the middle of the welding line, or at the end of a straight welding line, preventing the occurrence of stress concentration due to thermal shrinkage due to welding, The present invention provides a thin plate welding method for preventing blistering starting from this point.

  The gist of the present invention described in claim 1 is that a circular welding line is formed at a corner portion or an end portion of a straight welding line existing in the middle of a thin plate welding line.

  According to the first aspect of the present invention, since the corners in the middle of the welding line and the ends of the straight welding line are formed into a circular welding line, this portion does not become a point of stress concentration and is generated by welding. The occurrence of blistering can be prevented.

  The gist of the present invention described in claim 2 is that the circular welding line is formed by cutting a thin plate into a circular shape, closing the cut portion with a circular plate, and welding the peripheral edge of the circular plate.

  According to the second aspect of the present invention, the circular welding line can be formed by cutting the thin plate into a circular shape and then closing the cut portion with a circular plate to weld the peripheral edge of the circular plate. As a method, it is only necessary to change the direction of the welding line, and it can be easily handled on site.

  The gist of the present invention described in claim 3 is that the welding line is welded in advance by a straight welding line and then a circular welding line is welded.

  According to this invention of Claim 3, it becomes easy to weld a circular welding line by preceding a straight welding line.

  As described above, the thin plate welding method of the present invention has a circular or arcuate shape at the corner or the end of the welding line when the corner exists in the middle of the welding line or at the end of the straight welding line. Since the welding line is provided, it is possible to prevent the occurrence of stress concentration due to thermal contraction due to welding at this point, and it is possible to prevent blistering starting from this point.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view showing a first embodiment of the thin plate welding method of the present invention. In the figure, the same components as those of the conventional example shown in FIG.

  1st Embodiment is the case where the edge part of the welding lines 2 and 2 by the two straight parts 4 collides at right angle, and the corner | angular part 3 has generate | occur | produced, The circular welding line 7 is provided in the location of this corner | angular part 3 Form.

  The circular welding line 7 is formed by cutting out the thin plates 1 and 1 that are objects to be welded into a circular shape at the corners of the butt, closing the cut portion with the disc 8, and surrounding the periphery of the disc 8. Weld to thin plate 1.

  And in order to weld the thin plates 1 and 1, first, after welding the linear part 4 of the welding line 2, the circular welding line 7 by the disc 8 is welded. As a result, the corner portion 3 existing in the middle of the welding line 2 becomes a circular welding line 7, and this portion does not become a point of stress concentration, and the occurrence of swelling caused by thermal contraction due to welding is prevented. Can be prevented.

  FIG. 2 shows a second embodiment, in which the welding line 2 includes only the straight line portion 4, and a circular welding line 7 is formed at the end of the straight line portion 4. As a result, stress due to heat shrinkage due to welding does not concentrate at the end portion, and swelling does not occur.

  FIG. 3 shows a third embodiment. When the four welding lines 2 including the straight portions 4 cross in a cross shape, the intersection is formed in a circular welding line 7. Therefore, stress due to heat shrinkage due to welding does not concentrate at this intersection, and swelling does not occur.

  FIG. 4 shows a fourth embodiment, in which the end portions of the three welding lines 2 composed of the straight portions 4 are butted in a T shape, and a circular welding line 7 is formed at the end portions. Therefore, stress due to heat shrinkage due to welding does not concentrate at this end, and swelling does not occur.

It is explanatory drawing which shows 1st Embodiment of the welding method of the thin plate of this invention. It is explanatory drawing which shows 2nd Embodiment of the welding method of the thin plate of this invention. It is explanatory drawing which shows 3rd Embodiment of the welding method of the thin plate of this invention. It is explanatory drawing which shows 4th Embodiment of the welding method of the thin plate of this invention. It is explanatory drawing which shows the example of the welding method of the conventional thin plate. It is explanatory drawing of the concentrated stress which generate | occur | produces in a corner | angular part by welding of a thin plate. It is explanatory drawing of the concentrated stress which generate | occur | produces in an edge part by welding of a thin plate.

DESCRIPTION OF SYMBOLS 1 Thin plate 2 Welding line 3 Corner | angular part 4 Straight line part 5 Intersection 6 Intersection 7 Circular welding line 8 Disc 10 Swelling

Claims (3)

  A thin plate welding method, wherein a circular welding line is formed at a corner portion or an end portion of a straight welding line existing in the middle of a thin plate welding line.   2. The thin plate welding method according to claim 1, wherein the circular welding line is formed by cutting the thin plate into a circular shape, closing the cut portion with a circular plate, and welding the peripheral edge of the circular plate.   The thin plate welding method according to claim 1 or 2, wherein the welding line is welded in advance by a straight welding line, and then a circular welding line is welded.

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