JP3591518B2 - Laminated plate used as bulge forming material and welding method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a laminated plate material used as a bulge forming material and a method for welding the same, and in particular, a pressure medium is introduced between the plate materials of a material obtained by welding at least two sheets and then welding the entire periphery thereof. The present invention relates to a superposed plate material suitable for use as a bulge forming material when expanding or bulging into a hollow molded product having a so-called middle structure or a bag structure, and a welding method therefor.
[0002]
[Prior art]
As a method of forming a hollow molded product called a so-called middle structure or bag structure, two sheets are superimposed and welded around the entire circumference, and the superposed sheets are constrained by a mold. There is known a hydraulic bulge forming method in which, for example, a hydraulic pressure is introduced between the plate members to expand or bulge. In this case, each plate material forming the laminated plate material may be a simple flat plate-shaped one or a part of which is preformed in a predetermined shape, and it is essential that the inside has a completely closed structure.
[0003]
[Problems to be solved by the invention]
Regarding the welding form or the welded joint structure of the overlapped plate material used in such a hydraulic bulge forming method, regardless of the difference in the material, for example, as shown in FIGS. Continuous perimeter welding using the meat welding method or the lap seam welding method is adopted.However, in the case of the lap fillet welding method and the lap seam welding method, it is necessary to secure a sufficiently large welding margin, and the material yield is reduced. The decline is forced. In addition, in the case of the edge joint structure, there is an advantage that the welding margin can be relatively small, but on the other hand, since the effective joining area is small, it is difficult to secure the joining strength necessary for bulge molding, and the shape of the moldable product is remarkably large. It is not preferable because it is restricted. In FIG. 6, reference numerals 51 and 52 denote upper and lower plate members, 53 denotes a weld bead, and 54 denotes an electrode.
[0004]
In addition, especially in the case of the lap fillet welding method of FIG. 6B, the so-called single stroke welding method is considered to be the best, and in order to cope with this, for example, as shown in FIGS. 7A and 7B. Although the upper plate 51 and the lower plate 52 have similar shapes, the contour of one plate is formed to be slightly larger than that of the other plate in advance. For this reason, in particular, in the mass production process, an independent punching press die is required for each of the upper plate 51 and the lower plate 52, which undesirably increases the equipment cost and lowers the material yield.
[0005]
The present invention has been made in view of such a problem, and in particular, a lap which can easily secure a welded joint strength required for bulge forming without causing a rise in equipment cost and a decrease in material yield. An object of the present invention is to provide a laminated plate material and a welding method thereof.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 is that, when at least two plate members are overlapped, a pressure medium is introduced between the plate members of the material obtained by welding the entire periphery thereof to expand and deform into a molded product shape. It is a laminated plate material used as a bulge forming material, and at least two plate materials having contours formed in the same shape are offset from each other in a plate material plane so that the contours of both do not match at any position, and in that state, It is characterized by continuous welding all around.
[0007]
Each plate material forming the laminated plate material may be a simple flat plate shape or a partially pre-formed one in a predetermined shape. Further, if at least the contour shape is the same, the shape of both plate materials is not necessarily perfect. It does not need to match. If, for example, the plate material is rectangular, the two plate materials can be positively shifted in the diagonal direction and offset, so that the contours of the two plate materials match at any position. The relationship does not. The offset amount is desirably 0.2 t or more, where t is the plate thickness of the plate material.
[0008]
In this case, in order to reduce the welding margin, it is desirable to perform the fillet welding by using the corner formed by offsetting the two plate materials as a welding line as described in claim 2.
[0009]
Further, the invention described in claim 3 is a method in which the invention described in claim 1 is grasped in terms of method, and at least two plate members having the same contour are formed by any two contours. It is characterized in that they are offset from each other in the plate material plane so that they do not coincide even at the position, and continuous welding is performed on the entire circumference in the offset state.
[0010]
Similarly, the invention described in claim 4 is a method in which the invention described in claim 2 is grasped in terms of a method, and a corner formed by offsetting two sheet materials is overlapped as a welding line. It is characterized by performing meat welding.
[0011]
Therefore, in the inventions according to the first to fourth aspects, at least two plate members having the same contour shape are offset from each other, so that the edge (outer peripheral end surface) which is the contour line of both plate members is shifted. Therefore, the intended purpose is achieved by, for example, lap fillet welding along the edge to be located inside. In this case, the welding line is not completely closed loop on the front side or the back side of the superposed plate, but separates into the front and back sides. The continuity of the welding lines, that is, continuous welding of the entire circumference, becomes possible by making them continuous with each other.
[0012]
【The invention's effect】
According to the first and third aspects of the present invention, it is possible to perform continuous welding all around by simply arranging the plate members of the same shape up and down while offsetting them. It is possible to reduce the cost, improve the material yield, and also reduce the manufacturing cost of the press die for punching the plate material.
[0013]
According to the second and fourth aspects of the present invention, the entire circumference continuous welding is performed by lap fillet welding. Therefore, in addition to the same effects as the first and third aspects of the invention, bulge forming is performed. In addition to the above, it is possible to secure a larger welding joint strength required for welding, and also to obtain an advantage that the welded sealing property of the laminated plate material is further improved.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
1A and 1B are diagrams showing a preferred embodiment of the present invention, in which FIG. 1A is a perspective view of a laminated plate after welding, and FIG. 1B is a cross-sectional view taken along line AA in FIG. Each is shown.
[0015]
As shown in FIGS. 1 (A) and 1 (B), the laminated plate 1 presupposed to be used for the hydraulic bulge forming described above is a two-sheet preformed so that the central portion swells. After the plates 2 and 3 are overlapped with each other, continuous welding is performed on the entire periphery thereof to form a sealed structure. That is, when the rectangular upper plate 2 and the lower plate 3 punched out so as to have the same contour shape are overlapped with each other, they are offset in the plate material plane so as to be shifted in a diagonal direction with respect to each other. It is assumed that the two or three contours are positively offset so that they do not match at any position. It goes without saying that the width L1 of the upper plate 2 and the lower plate 3 are the same. The offset amount α at each of the four circumferences is set to 0.2t or more, where t is the thickness of the upper plate 2 and the lower plate 3.
[0016]
Due to the offset between the upper plate 2 and the lower plate 3, the lip which is the contour of the two sides 2 a on the upper plate 2 side is on the inner side of that on the lower plate 3 side, and conversely, On the back side of the laminated plate 1, the lip, which is the contour of the two sides 3 a on the lower plate 3 side, is on the inner side than that on the upper plate 2 side. All round continuous welding is performed by lap fillet welding. For example, while the edge of the two sides 2a which is inside on the front side of the superposed plate 1 is overlap-welded with the welding bead 4 on the front side, the two sides 3a which are inside on the back side of the superposed plate 1 Fillet welding is performed on the rim with the welding bead 5 on the back side, and the ends of the welding beads 4 and 5 are overlapped with each other to have continuity as a welding line. As a result, continuous welding is performed on the entire periphery of the upper plate 2 and the lower plate 3 to obtain a laminated plate 1 having a completely sealed structure, and the laminated plate 1 is formed by the hydraulic bulge forming as described above. Used as a material for
[0017]
As described above, according to the laminated plate 1 of the present embodiment, the plates 2 and 3 formed in exactly the same shape are overlapped while being offset from each other, and continuous welding is performed on the entire periphery by fillet welding. Therefore, it is not necessary to punch the upper plate 2 and the lower plate 3 into different shapes to secure a welding margin. In addition, it is possible to weld lap fillets with the minimum required welding margin while welding the plate members 2 and 3 of the same shape, thereby improving the material yield and required for hydraulic bulge forming. It is possible to secure a high welding joint strength.
[0018]
FIGS. 3 to 5 show a second embodiment of the present invention, in which a superposed plate member used for hydraulic bulge molding of a hollow molded product 6 having a so-called hollow shape as shown in FIG. 11 shows an example.
[0019]
As shown in the drawing, the upper plate 12 and the lower plate 13 previously punched into a hollow shape are overlapped and offset in the diagonal direction. Set to 2t or more. Then, by welding from both the front and back sides, the weld bead 14 is continuously welded by fillet welding on the front surface side of the overlapped plate material 11 on both the inner and outer circumferences, and the weld bead 15 is overlapped on the back surface side of the overlapped plate material 11 by welding. Continuous welding by fillet welding is performed, and the welding beads 14 and 15 are continuously overlapped with a predetermined overlapping amount β as shown in FIGS. 4 and 5 so that the welding line becomes a closed loop shape. In FIG. 3, a solid arrow 7 indicates a movement locus of the welding torch for the front side weld bead 14, and a broken arrow 8 indicates a movement locus of the welding torch for the rear side weld bead 15. ing.
[0020]
The same function as that of the first embodiment is exerted also in the superposed plate 11 of the second embodiment.
[Brief description of the drawings]
FIGS. 1A and 1B are diagrams showing a first preferred embodiment of the present invention, wherein FIG. 1A is a perspective view of an overlapped plate, and FIG. 1B is an enlarged sectional view taken along line AA of FIG.
FIG. 2 is a perspective view showing a molded product formed by bulging the laminated plate shown in FIG. 3 as a raw material.
FIG. 3 is an explanatory view showing another example of a laminated plate as a second embodiment of the present invention.
FIG. 4 is an enlarged view of a portion B in FIG. 3;
FIG. 5 is a view in the direction of arrow C in FIG. 4;
6 (A) to 6 (C) are cross-sectional explanatory views of a main part showing a conventional typical welded joint structure used for a laminated plate.
7A and 7B are views showing the structure of a conventional laminated plate material, wherein FIG. 7A is a perspective view thereof, and FIG. 7B is an enlarged sectional view taken along line MM of FIG. 7A.
[Explanation of symbols]
1: Overlapping plate 2: Upper plate (plate)
3. Lower plate (plate material)
4 ... Welding bead 5 on the front side 5 ... Welding bead 6 on the back side 6 ... Bulge-formed molded article 11 ... Laminated plate 12 ... Top plate (plate)
13 Lower plate (plate material)
14: welding bead on the front side 15: welding bead on the back side α: offset amount

Claims (4)

A lapping plate used as a bulge forming material when a pressure medium is introduced between plates of a material obtained by laminating at least two sheets and welding the entire periphery thereof to expand and deform into a molded product shape And
At least two plate members having at least the contours formed in the same shape are offset from each other in the plate material plane so that the contours of the two plates do not coincide at any position, and continuous welding is performed on the entire circumference in that state. Laminated plate used as bulge forming material. The overlapped plate material used as a bulge forming material according to claim 1, wherein the fillet welding is performed using a corner formed by offsetting the two plate materials as a welding line. A lapping plate used as a bulge forming material when a pressure medium is introduced between plates of a material obtained by laminating at least two sheets and welding the entire periphery thereof to expand and deform into a molded product shape A method of welding
At least two plate materials having the same contour formed in the same shape are offset from each other in the plane of the plate material so that the contours of both do not match at any position,
A method for welding lap sheet material used as a bulge forming material, wherein continuous welding is performed on the entire circumference in the offset state. The method according to claim 3, wherein the fillet welding is performed by using a corner formed by offsetting the two plates as a welding line and performing fillet welding.

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