JP3774212B2 - Sheet metal parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet metal part in which one end of two metal plates is butt welded or layered and welded to form an integral metal plate, and the integral metal plate is formed into a target shape by press molding, in particular, for example, The present invention relates to a sheet metal part structure capable of easily confirming the welding quality of a sheet metal part such as a frame or a cross member in an automobile in which poor welding causes an important safety problem.
[0002]
[Prior art]
For example, in a side frame of an automobile, in order to easily absorb an impact by deformation at the time of a frontal collision, a metal plate for a front frame having a thin plate thickness and a low strength, and a metal plate for the front frame In comparison, the metal plate for the rear frame, which is set to be thick and high in strength, is laminated and welded in layers by butt welding by laser welding or mash seam welding to form an integrated metal plate, An integral metal plate is formed into a desired side frame shape by press molding.
[0003]
Here, as shown in FIG. 3, the mash seam welding is performed by applying a pair of disk electrodes 21 and 22 to pressurize and feed, and the overlapping portion is set to be smaller than the width of the disk electrode. More specifically, the materials to be welded 1 and 2 made of the pair of metal plates are overlapped, and the overlapped portion is pressurized by the pair of disk electrodes 21 and 22 to be welded. While applying the welding current obtained from the transformer 23 or the like to the one disc electrode 21, the welded materials 1 and 2 are continuously heated and melted in accordance with the rotation of the disc electrode to weld the overlapped portion. Is.
[0004]
[Problems to be solved by the invention]
Now, since important safety parts such as suspensions, engines, transmissions, and special guarantee parts are attached to the side frames as described above, poor welding of the frames is likely to become a serious problem of the vehicle.
For this reason, it is desirable to check the total quality of the mash seam welded portion of the side frame. For this reason, inspection after press working or at the stage of a complete vehicle is being considered.
[0005]
However, in order to perform an accurate inspection, it is not sufficient to perform an appearance inspection alone, and it cannot be determined that the welded portion is cut and enlarged by a macro test. Furthermore, it is painted at the stage of the finished vehicle, and other parts are also mounted, so quality cannot be confirmed at all by visual inspection.
[0006]
In view of such problems, an object of the present invention is to provide a sheet metal part such as a side frame that can accurately check the quality of a welded part only by appearance inspection.
[0007]
[Means for Solving the Problems]
The present invention is applied to a sheet metal part in which one end of two metal plates 1 and 2 is butt welded or laminated and welded in layers to form an integral metal plate, and the integral metal plate is formed into a target shape by press molding. To do.
Therefore, the sheet metal part to which the present invention is applied is limited to the automobile side frame 10 and other automobile parts as long as the two metal plates 1 and 2 (see FIG. 1) are press-formed after welding. It is not a thing.
Further, the welding means is not limited to mash seam welding or laser welding as long as one end of the two metal plates 1 and 2 is butt welded or layered and welded in layers, and includes other welding means.
[0008]
And the present invention is a sheet metal part formed by welding one end of two metal plates 1 and 2 to each other in a linear form to form an integral metal plate, and press forming the metal plate.
The bulging part 4 is formed in the welding part 3 of the sheet metal part by the press molding so that the height of the bulging part 4 does not generate cracks or cracks in normal welding and cracks or cracks in abnormal welding. The bulging part 4 exists until after the said press molding, while setting to a certain height.
When the sheet metal part is configured as a side frame of a vehicle, the two metal plates are a front frame metal plate that forms a front portion of the vehicle side frame and a rear frame that forms a rear portion of the side frame. The rear frame metal plate is preferably applied to a side frame of a vehicle provided with a thicker plate than the front frame metal plate.
[0009]
According to this invention, at the stage where the press molding is completed, by visually inspecting the bulging portion 4 or the periphery thereof, it is possible to immediately determine that there is a welding failure when a crack or a crack has occurred, for example, Before assembling the side frames 10, it is possible to check the total number at the stage of finishing the single product.
Further, since the cracks and cracks of the bulging portion 4 can be checked by visual inspection at the stage of the finished vehicle, reliable quality assurance can be achieved.
[0010]
Further, in the present invention, at least a portion of the two metal plates 1 and 2 that extends over the welded portion 3 has an extension in a direction intersecting with the weld line, more specifically in a direction perpendicular to the weld line than the other welded portions 3 The bulging part 4 which becomes partially high is provided.
[0011]
The bulging part 4 is preferably a bulging part 4 that is bulged from the surface of the metal plates 1 and 2 in a shape such as a hemispherical shape, a U-shape, or a polygonal pyramid, with an elongation equal to or less than the welding strength. .
The bulging portion 4 is a pressing die (for example, a lower press die) in which the upper side of the bulging portion is pressed from the bottom side of the bulging portion 4 under the escape portion 14 or free space while the periphery of the welding portion 3 is pressed. It is good to form by only plastic deformation.
[0012]
According to this invention, the bulging portion 4 can obtain the same effect as the Erichsen test that is practically used for the material overhang formability evaluation test, and cracks and the like occur on the surface of the bulging portion 4. It is possible to easily confirm the welding quality by visually observing whether or not it is visible with a magnifying glass or the like.
The Eriksen test method is used for the overhang formability test of a single plate material such as press forming specified in “JIS Z2247 and ISO R149 1960 Modified Cupping Test”, etc. It is knowledge of the invention.
[0013]
The Erichsen test will be described in more detail. This test is widely used as a practical test method for examining the formability of a metal plate, and the test material is a single plate material having a thickness in the range of 0.1 to 2 mm. , The press plate is fixed around the 90 × 90 mm test plate. This fixing is not rigid fixing, but a small gap is provided according to the plate thickness.
Then, it is pushed out with a spherical punch having a diameter of 20 mm to perform overhanging. Punch indentation depth when the indentation progresses and cracks or cracks occur in the test plate is set to the Erichsen value, and formability is evaluated.
[0014]
The present invention utilizes the above-mentioned Eriksen test in a reverse idea. That is, the known Erichsen test is to determine the punch indentation depth until cracks or cracks occur in the test plate. However, the present invention conversely determines the height H (high stretch portion extension amount) of the bulging portion 4. It is set so that cracks and cracks do not occur in normal welding that can guarantee quality, and cracks and cracks occur in the case of abnormal welding (welding failure) that cannot guarantee quality. Thereby, it is possible to easily confirm the welding quality by visually observing whether the surface of the bulging portion 4 is cracked or the like with a visual or magnifying glass.
[0015]
As described above, when the sheet metal part is configured as a vehicle side frame, the two metal plates are a front frame metal plate that forms a front side portion of the vehicle side frame, and a rear side of the side frame. In the case of a metal plate for a rear frame that forms a part, the metal plate for the front frame and the metal plate for the rear frame are preferably welded in the line shape so that one end of the metal plate overlaps each other in layers. In this case, it is preferable that the bulging part has a diameter larger than the overlap welding part width so that the diameter is applied to the superposed welding part.
Further, in the vehicle side frame in which the metal plate for the rear frame is provided thicker than the metal plate for the frame, the bulging portion is formed from the side of the metal plate for the front frame by a press die. It is good to bulge and form in the surface side of the said metal plate for rear frames by pressing to the metal plate side.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.
Hereinafter, a processing procedure of the side frame 10 according to the embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2.
[0017]
FIG. 2 shows a processing procedure of the side frame 10.
For example, a steel plate with a thickness of 1.4 mm is used as the steel plate 1 for the front frame, and a steel plate with a thickness of 2.3 mm is used as the steel plate 2 for the rear frame.
After the rear frame steel plate 2 is cut into a predetermined shape in advance, a. As shown in FIG. 1, the side edges of the steel plates 1 and 2 are overlapped in layers, and the overlapping portion is pressed with a pair of disc electrodes 21 and 22 while applying a welding current to the one disc electrode 21. In accordance with the rotation of the disk electrodes 21 and 22, it is continuously heated and melted to seam weld the overlapped portion.
[0018]
Steel plates 1 and 2 having different thicknesses are integrated by seam welding to form a welded portion. Next, b. As shown in FIG. 4, the side frames 10 having a desired shape are formed by press molding the integrated steel plates 1 and 2 using a press upper die 11 having a forming concave portion and a press lower die 12 having a forming convex portion. The side frame 10 is c. As shown in FIG. 4, a predetermined assembly is completed, and a predetermined vehicle is completed through a vehicle assembly line.
[0019]
And b. The press lower die 12 used in the pressing step is a substantially hemispherical punch projection 13 at least on the portion of the two steel plates 1 and 2 that overlaps the welded portion 3, and the upper press die 11 includes the press A recess portion 14 having a substantially cylindrical recess shape is provided at a position corresponding to the punch protrusion 13 provided on the lower mold 12.
[0020]
According to such a configuration, the press upper die 11 and the press lower die 12 are used to perform press working, so that the press upper die 11 is pressed around the welded part 3 by the press dies 11 and 12. Under the upper free space formed by the escape portion 14, the punch projection 13 presses the lower side of the welding portion 3 from the bottom side of the bulging portion 4, and a substantially hemispherical bulging portion 4 is formed by plastic deformation by the protrusion. The
[0021]
FIG. 1 shows a side frame 10 formed on the basis of such a processing procedure, in which a substantially hemispherical bulging portion 4 is formed at a portion of at least the welding portion 3 of two steel plates.
The bulging portion 4 is formed in a hemispherical shape having a diameter of about 20 mm as shown in the AA enlarged view, and the quality H of the bulging portion 4 (high extension portion extension amount) can be guaranteed. In normal welding, cracks and cracks do not occur, and the settings are made so that cracks and cracks occur in the case of abnormal welding (welding failure) for which quality assurance is not possible.
[0022]
According to such an embodiment, at the stage where the press working is completed, by visually inspecting the bulging site 4 or its periphery, it can be immediately determined that there is a weld failure when cracks or cracks occur, Before assembling the side frames 10, it is possible to check the total number at the stage of finishing the single product.
Further, since the cracks and cracks of the bulging portion 4 can be checked by visual inspection at the stage of the finished vehicle, reliable quality assurance can be achieved.
[0023]
【The invention's effect】
As described above, according to the present invention, the quality of the welded portion can be confirmed with high accuracy only by visual inspection. Therefore, even in the case of vehicle frame members to which important safety parts and special warranty parts are attached, accuracy can be obtained only by visual inspection. It is possible to determine a good welded portion, and as a result, it is possible to check the total number and to check the quality by appearance inspection during the production process or at the stage of the finished vehicle.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a side frame formed based on the processing procedure of FIG. 2 and a sectional view taken along line AA.
FIG. 2 shows a processing procedure for a side frame according to an embodiment of the present invention.
FIG. 3 is a schematic view of a mash seam welding method.
[Explanation of symbols]
1, 2 Metal plate (steel plate)
4 Swelling part 3 Welding part 10 Side frame 11 Press upper die 12 Press lower die 13 Punch protrusion 14 Escape part 15 Overlapping part

Claims (8)

In a sheet metal part formed by welding one end of two metal plates to each other linearly to form an integral metal plate and press-molding the metal plate,
A bulge part is formed by the press molding at the weld part of the sheet metal part, and the height of the bulge part is such that cracks and cracks do not occur in normal welding and cracks and cracks occur in abnormal welding. And the bulging portion exists until after the press molding. The two metal plates are a front frame metal plate that forms a front portion of a side frame of a vehicle and a rear frame metal plate that forms a rear portion of the side frame. Sheet metal parts. The sheet metal part according to claim 2, wherein the rear frame metal plate is provided on a thicker plate than the front frame metal plate. 4. The sheet metal part according to claim 3, wherein the metal plate for the front frame and the metal plate for the rear frame are welded in the linear shape so that one end of the metal plate is overlapped in a layered manner. The bulging part is formed by bulging to the surface side of the rear frame metal plate by pressing from the front frame metal plate side to the rear frame metal plate side by a press die. The sheet metal part according to claim 3, wherein The sheet metal part according to claim 3, wherein the bulging portion has a diameter larger than a width of the overlap welding portion so that a diameter thereof is applied to the overlapped welding portion. The sheet metal part according to claim 3, wherein the bulging portion is formed so that the elongation in the direction intersecting the welding line is partially higher than other welding portions. The sheet metal part according to claim 7, wherein the bulging portion has a substantially hemispherical shape, a U shape, or a polygonal pyramid shape.

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