JP4321072B2 - Laminated plate material for hydraulic forming - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminated plate material used as a material for hydraulic forming, and in particular, a plurality of metal plates are overlapped and welded to the peripheral portion thereof, and a hollow shape is introduced by introducing hydraulic pressure therein. The present invention relates to an improvement of a laminated plate material used as a raw material when bulging and forming a structure of the above.
[0002]
[Prior art]
In the so-called hydroforming method (hydraulic bulge forming method), a plurality of metal plates are overlapped and then continuously welded to the periphery thereof to form a liquid inside the overlapped plate material. The basic structure is to form a hollow structure by introducing pressure and causing it to swell. However, an airtight test (leak test) is performed particularly on the welded portion in the state of a single laminated plate. . In addition, the basic techniques of the hydraulic forming method and the laminated plate material are described in Patent Documents 1 to 3, for example.
[0003]
In addition to the method of determining the suitability of airtightness based on the presence or absence of bubbles by submerging the overlapped plate material in which the gas is sealed, the overlapped plate material has a gas tightness test in the atmosphere. The mainstream is a method of determining the suitability of airtightness based on the presence or absence of leakage.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-85944
[Patent Document 2]
Japanese Patent Laid-Open No. 11-347643
[Patent Document 3]
Japanese Patent Laid-Open No. 2002-96116
[Problems to be solved by the invention]
Since the laminated plate material after welding is in a state where the metal plates are in close contact with each other and almost no gap is secured between them, even if a gas sealing pressure is applied in the airtightness test, It takes time to detect a leak at that portion due to the pressure acting on it, and improvement in productivity cannot be expected.
[0008]
In addition, oil and fat containing fine metal powder, that is, oil mud constrictions, are present between the metal plates that make up the laminated plate material. In the original case, leakage should occur due to the application of pressure, but the above-mentioned oil mud constriction may be clogged from the inside into a poorly welded part, and leakage cannot be detected. Not always enough.
[0009]
The present invention has been made paying attention to the problems as described above, and in particular, in the airtightness test in the state of the laminated plate alone, the airtightness in the welded portion is not affected by the above-mentioned oil mud constriction. It is an object of the present invention to provide a structure that can accurately determine the suitability of sex.
[0010]
[Means for Solving the Problems]
According to the first aspect of the present invention, when a plurality of metal plates are overlapped and welded to the peripheral portion thereof, and a hydraulic pressure is introduced into the hollow structure to bulge and form the hollow structure. It is a laminated plate material used as a raw material, and in order to secure a minute thickness gap between a plurality of metal plates, it will swell between the plurality of metal plates and at the time of expansion molding It is characterized in that any one of a linear shape, a sealing tape shape, a granular shape, and a gel shape is interposed and fixed as a spacer in advance at the site.
[0011]
The spacer is preferably made of an elastic material.
[0012]
Therefore, in the invention described in claim 1, since a minute gap (gap) corresponding to the thickness of the spacer is secured between the metal plates constituting the laminated plate material, When the sealing pressure is applied, the pressure immediately acts on the welded part without being affected by oil mud confinement. In the unlikely event that there is a weld failure such as a poor penetration or undercut in the welded part, a leak will immediately occur as a poor airtightness.
[0013]
【The invention's effect】
According to the first aspect of the present invention, since a minute gap is secured by interposing a spacer in advance between the metal plates constituting the overlapping plate material, the airtightness of the overlapping plate material alone. When gas is sealed during the test, the pressure acts instantaneously on the welded part without being affected by oil mud and the like, and the airtightness test can be performed accurately and reliably.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 are views showing a preferred embodiment of the present invention.
[0015]
As shown in FIG. 1A, when the laminated plate material 1 is manufactured by superimposing the metal plates 2a and 2b on the two pieces cut into a predetermined blank size, between the two metal plates 2a and 2b. For example, a very thin tube 3 having a closed loop shape and having a self-elastic force is interposed as a spacer, and the tube 3 is pressed and held between the metal plates 2a and 2b as shown in FIG. The metal plates 2a and 2b are pressed and restrained by a jig 4, and the peripheral portions of the metal plates 2a and 2b are continuously welded by laser welding or the like to obtain a laminated plate material 1. In FIG. 1, (B), 5 indicates a welding torch, and 6 indicates a weld bead portion which is a welded portion. As a result, as shown in FIG. 5C, the tube 3 as a spacer is completely crushed and a predetermined gap 7 is secured between the metal plates 2a and 2b.
[0016]
Here, it is necessary to secure a gap (gap) 7 having a thickness of, for example, 5 μm or more between the metal plates 2a and 2b. Even if the tube 3 as a spacer is crushed, the gap 7 having a necessary dimension is provided. The diameter etc. shall be selected in advance so that it can be secured. In addition, it is important that the tube 3 does not move even when a test gas or the like is sealed in an airtightness test described later, and is fixed at a position relatively close to a portion to be welded by using an adhesive or the like together. The fixed position is fixed in advance.
[0017]
In the airtightness test with the single laminated plate 1 (single unit), as shown in FIG. 1C and FIG. 2, the opening 8 formed in advance on one metal plate 2b is used for the airtightness test. Then, a predetermined test gas is sealed in the gap 7 formed between the metal plates 2a and 2b to increase the internal pressure. At this time, since the gap 7 is secured between the metal plates 2a and 2b in advance, if the gas pressure is applied, the gas pressure instantaneously reaches the weld bead portion 6 which is the terminal weld portion. Become. And, for example, when there is a fine through hole 10 in the weld bead 6 due to poor welding such as poor penetration or undercut, the tube 3 is fixed in position because the tube 3 is fixed in position. The hole 10 is not blocked, and a gas leak from the through hole 10 is immediately determined as an airtight defect.
[0018]
As described above, according to the present embodiment, a minute gap 7 is secured in advance between the metal plates 2a and 2b constituting the overlapped plate material 1, so that the metal plate 2a as in the prior art. , 2b, the air tightness test can be performed accurately without being affected by the oil mud constriction and the like.
[0019]
FIG. 3 shows a second embodiment of the present invention. As shown in FIGS. 3A and 3B, as a spacer between the metal plates 12a and 12b constituting the overlapping plate material 11, FIG. A thin silk twisted yarn 13 is interposed, and is fixed in advance to a position to be welded, that is, a position close to the weld bead portion 6 by using an adhesive together. Thereby, in the state of the laminated plate material 11 alone, a minute gap 7 according to the thickness of the silk twisted yarn 13, preferably a gap 7 having a thickness of 5 μm or more is secured between the metal plates 12 a and 12 b.
[0020]
Therefore, when a predetermined test gas is sealed in the laminated plate material 1 in the airtightness test as shown in FIG. 5B, the above-described silk twisted yarn 13 has the same function as the tube 3 of the previous embodiment. Will be demonstrated.
[0021]
On the other hand, when the hollow structure W is formed by the hydraulic forming method using the laminated plate material 11 as a raw material as shown in FIG. 3C, the silk twisted yarn 13 as the spacer is a weld bead portion. Even if it is positioned in the vicinity of 6, it does not have any adverse effect on the molding method or the product function.
[0022]
FIG. 4 shows a third embodiment of the present invention. As shown in FIGS. 4A and 4B, a predetermined spacer is provided between the metal plates 22a and 22b constituting the laminated plate material 21. FIG. A thick Japanese paper tape 23 is attached and interposed, and is fixed in advance with an adhesive or the like at a position to be welded, that is, a position relatively close to the weld bead portion 6. Therefore, in the state of the overlapped plate material 21 alone, a minute gap 7 according to the thickness of the Japanese paper tape 23, preferably a gap 7 having a thickness of 5 μm or more is secured between the metal plates 22a and 22b.
[0023]
Therefore, as shown in FIG. 5B, when a predetermined test gas is sealed in the laminated plate material 21 in the airtightness test, the above Japanese paper tape 23 is equivalent to the tube 3 of the first embodiment. The function will be demonstrated.
[0024]
On the other hand, when the hollow structure W is formed by the hydraulic forming method using the laminated plate material 21 as a raw material as shown in FIG. 5C, the washi tape 23 is a weld bead portion. Even if it is positioned in the vicinity of 6, it does not have any adverse effect on the molding method or the product function.
[0025]
Here, the spacer is not limited to those exemplified in each of the above-described embodiments. In short, the metal plates 2a, 2b, 12a, 12b, What is necessary is just to be able to ensure the predetermined space | gap 7 between 22a, 22b, for example, it is also possible to use a granular or gel-like thing as needed.
[0026]
Further, as described above, the tube 3 as a spacer interposed between the metal plates 2a, 2b, 12a, 12b, or 22a, 22b in the state of the stacked plate materials 1, 11, 21 alone. Since the silk twisted yarn 13 or the Japanese paper tape 23 loses its function at the stage of being formed as a hollow structure W having a predetermined shape, it is washed, welded, When post-processing or post-processing such as painting is performed, or when equivalent post-processing or post-processing is performed after being formed into a hollow structure W, or when actually used as a product, It is desirable to have disappearance such as water solubility that will surely disappear. By doing so, it is not necessary to remove the tube 3, the silk twisted yarn 13, or the Japanese paper tape 23 as a spacer that loses its function when it is formed as the hollow structure W as described above. .
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view showing a manufacturing procedure of a laminated plate material and a procedure of an airtightness test as a preferred embodiment of the present invention, and (A) shows a state in which a tube as a spacer is interposed between metal plates. Sectional drawing, (B) is a sectional view at the time of welding of metal plates, (C) is a sectional explanatory view at the time of an airtightness test of the laminated plate material manufactured in the same drawings (A), (B).
FIG. 2 is an enlarged cross-sectional view of the main part of FIG.
FIGS. 3A and 3B are diagrams showing a second embodiment of the present invention, where FIG. 3A is an explanatory plan view of a laminated plate material, and FIG. 3B is a key point in an airtightness test of the laminated plate material of FIG. Part enlarged sectional view, (C) is a principal part enlarged sectional view when hydraulic forming.
FIGS. 4A and 4B are diagrams showing a third embodiment of the present invention, where FIG. 4A is a plan explanatory view of a laminated plate material, and FIG. 4B is a key point in the airtightness test of the laminated plate material of FIG. Part enlarged sectional view, (C) is a principal part enlarged sectional view when hydraulic forming.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Laminated board material 2a, 2b ... Metal plate 3 ... Tube (spacer)
6 ... weld bead (weld)
7 ... Gap 11 ... Laminated plate materials 12a, 12b ... Metal plate 13 ... Silk twisted yarn (spacer)
21 ... Overlapping plate materials 22a, 22b ... Metal plate 23 ... Japanese paper tape (spacer)

Claims (2)

This is a laminated plate material that is used as a raw material when a plurality of metal plates are stacked and welded to the peripheral edge and fluid pressure is introduced into the hollow structure to form a hollow structure. And
In order to secure a minute thickness gap between the plurality of metal plates , a linear, seal tape shape as a spacer in advance between the plurality of metal plates and the portion that will bulge during bulging molding A laminated plate material for hydroforming, characterized in that it is fixed by interposing one of a granular material and a gel material. The laminated plate material for hydraulic forming according to claim 1, wherein the spacer is made of an elastic body.

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