JP2022002850A - Closed cross section hollow structure and method for manufacture thereof - Google Patents

Abstract

To easily manufacture a closed cross section hollow structure formed by joining respective ends of two open cross section sheet metal components, which may have high joining accuracy in such a manner that concave shapes, that are engaged in a convex shape at ends joined to each other are formed by end bending molding.SOLUTION: A part of a pair of ends 11 of a first open cross section sheet metal components 10 is embossed on an outer side of a closed cross section hollow part 2 by only a plate thickness equivalent amount, whereby a recess 12 is formed. A projection piece 22, which projects toward the recess 12, is formed on a part corresponding to the recess 12 at a tip of the pair of ends 21 of a second open cross section sheet metal component 20. The first and second open cross section sheet metal components 10, 20 are engaged with each other in such a manner that the projection piece 22 is inserted in the recess 12 so as to suppress relative movements of both in a plate thickness direction (Y direction) of each of the pair of ends 11, 21.SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a closed cross-section hollow structure that can be used as a vehicle body component and a method for manufacturing the same.

Patent Document 1 discloses a method for manufacturing a closed-section hollow structure used for vehicle body components such as a suspension arm and a suspension subframe. Here, the joints of a pair of open-section sheet metal parts having a U-shaped cross-section, which form a closed-section hollow structure, are complementarily cut and aligned by a laser device to facilitate butt welding of the pair of open-section sheet metal parts. ing.

Further, Patent Document 2 discloses an invention in which a concavo-convex shape that meshes with each other at the time of joining is formed in a joint portion of a pair of open-section sheet metal parts to improve the joining accuracy.

Japanese Patent Publication No. 2013-514187 Japanese Unexamined Patent Publication No. 2001-233208

However, in the invention of Patent Document 2, it is necessary to form an uneven shape on the end face of the joint portion within the range of the plate thickness of the open-section sheet metal part, and in the case of a part having a plate thickness of about 2 to 3 mm, precision processing is possible. It is necessary and not easy to manufacture.

An object of the present invention is to create a concave shape that is engaged in a convex shape at the ends joined to each other in a closed cross-section hollow structure formed by joining the ends of two open-section sheet metal parts. It is an object of the present invention to easily manufacture a closed cross-section hollow structure having high joining accuracy by forming the hollow structure by bending.

In the first invention of the present invention, the first and second open-section sheet metal parts having a U-shaped cross section are joined to each other with their open sides facing each other, and the first and second ends thereof are joined to each other. A closed-section hollow structure in which a closed-section hollow portion is formed between open-section sheet metal parts, and at least one part of a pair of ends of the first or second open-section sheet metal part is the closed-section hollow. A recess is formed on the outside of the portion by an amount equivalent to the plate thickness, and the recess is formed at a portion corresponding to the recess at the tip of a pair of ends of the first or second open cross-section sheet metal part. The projecting pieces are formed so as to prevent the first and second open-section sheet metal parts from moving relative to each other in the plate thickness direction of the pair of ends. They are inserted into the recess and engaged with each other.

In the first invention, the U-shaped cross section has the same cross-sectional shape as the U-shaped groove and U-shaped steel, but also includes what is called a U-shaped cross section. The recesses and protrusions may be formed in either the first or second open cross-section sheet metal component. Further, the recess and the protrusion are formed on either one or both of the pair of ends of each open cross-section sheet metal part.

In the second aspect of the present invention, in the first invention, the combination of the recess and the protrusion is formed at the opposite position of each pair of ends of the first and second open cross-section sheet metal parts, respectively. ..

In the third aspect of the present invention, in the second invention, the recess is formed in the first open-section sheet metal part, and the protrusion is formed in the second open-section sheet metal part.

According to the fourth aspect of the present invention, in any one of the first to third inventions, the projecting pieces have a uniform plate thickness, and the plate surface of a pair of ends of the first or second open-section sheet metal part. The shape along the trapezoid is a trapezoid, and the short upper bottom of the parallel bases of the trapezoid is the side facing the recess.

In the fifth aspect of the present invention, in any one of the first to fourth inventions, the recess and the protrusion form the joint between the pair of ends of the first and second open cross-section sheet metal parts. It is performed by arc welding at the parts other than the parts that have been removed.

A sixth aspect of the present invention is the method for manufacturing a closed-section hollow structure according to the first aspect of the present invention, which is a semi-finished product obtained by shearing a plate material by a press to obtain the first and second open-section sheet metal parts. The first step in which the protrusions are formed on each pair of ends on the side of the semi-finished product having the protrusions, and the pair of the semi-finished products on the side having the recesses. The end portion is provided with a second step of forming the recess by punching out a press in the plate thickness direction.

In the seventh aspect of the present invention, in the sixth aspect of the present invention, in the first step, the recesses and the portions forming the protrusions are set to match at the time of pressing, and the punching and shearing process is performed.

According to the present invention, a concave shape that is engaged in a convex shape at each end of two open-section sheet metal parts joined to each other is formed by bending the ends. Therefore, a closed cross-section hollow structure with high joining accuracy can be easily manufactured.

It is a perspective view which shows one Embodiment of the closed cross-section hollow structure of this invention. It is a top view of the said embodiment. It is a front view of the said embodiment. FIG. 2 is an enlarged view of a cross section taken along the line IV-IV of FIG. It is explanatory drawing explaining the 1st process of forming the semi-finished product of the 1st open-section sheet metal part in the manufacturing method of the closed-section hollow structure of the said embodiment. It is explanatory drawing explaining the 2nd step in the manufacturing method of the closed-section hollow structure of the said embodiment. It is explanatory drawing explaining the 3rd step of forming the 1st open-section sheet metal part in the manufacturing method of the closed-section hollow structure of the said embodiment. It is explanatory drawing explaining the 1st process which forms the semi-finished product of the 2nd open-section sheet metal parts in the manufacturing method of the closed-section hollow structure of the said embodiment. It is explanatory drawing explaining the 3rd process of forming the 2nd open-section sheet metal parts in the manufacturing method of the closed-section hollow structure of the said embodiment. It is explanatory drawing explaining the 4th step in the manufacturing method of the closed-section hollow structure of the said embodiment. It is explanatory drawing explaining the 5th step in the manufacturing method of the closed-section hollow structure of the said embodiment.

<Structure of one embodiment>
FIGS. 1 to 4 show an embodiment of the closed cross-section hollow structure of the present invention. This embodiment is a closed cross-section hollow structure of a quadrangular prism having a simple external shape. However, when it is applied to vehicle body components such as suspension arms and suspension subframes, it has a unique appearance shape according to the applied parts. As shown by the arrows X, Y, and Z in FIGS. 1 to 4, each direction of the closed-section hollow structure 1 is in the X direction (or X1, X2 side), Y direction (or Y1, Y2 side), and Z. It will be described as a direction (or Z1, Z2 side).

In this embodiment, in the closed cross-section hollow structure 1, a pair of a first open-section sheet metal component 10 and a second open-section sheet metal component 20 having a U-shaped cross section face each other with their open sides facing each other. It is configured by joining the butted end faces 11a and 21a of the end portions 11 and 21 of the above. As a result, the closed cross-section hollow portion 2 is formed between the first and second open cross-section sheet metal parts 10 and 20. In this case, the first open-section sheet metal component 10 is arranged on the Z2 side, and the second open-section sheet metal component 20 is arranged on the Z1 side. The first and second open-section sheet metal parts 10 and 20 are each made of a steel plate having a plate thickness of about 2 to 3 mm.

A recess 12 is formed in the central portion of the first open-section sheet metal component 10 in the X direction. The recess 12 is formed by embossing a part of the pair of end portions 11 on the Y1 side and the Y2 side by the amount equivalent to the plate thickness, respectively. Therefore, the recess 12 is formed by recessing a part of the surfaces of the pair of end portions 11 facing each other from the general surface. Further, in the central portion of the second open-section sheet metal component 20 in the X direction corresponding to the recess 12, projecting pieces 22 are formed so as to project from a part of the pair of end portions 21. Each projecting piece 22 is projected to a size corresponding to the embossed molded portion of each recess 12, and can be inserted into the recess on the facing surface side of each recess 12. The combination of the projecting pieces 22 and the recesses 12 is formed at the opposite positions of the pair of end portions 11 and 21 of the first and second open cross-section sheet metal parts 10 and 20, respectively.

Each projecting piece 22 is formed by extending a pair of end portions 21 of the second open-section sheet metal component 20 toward the Z2 side. Each of the projecting pieces 22 is formed in a trapezoidal shape when viewed from the Y direction, and the plate thickness thereof is made uniform as a whole. In this trapezoid, the Z2 side facing the recess 12 is a short upper base among the bases parallel to each other. Further, in the trapezoid, the Z1 side connected to the pair of end portions 11 is a lower base having a long base, and the height in the Z direction is slightly smaller than the lower base. By making such a dimensional relationship, it is possible to reduce the bending moment received in the Y direction at the lower bottom portion of each projecting piece 22 in a state where each projecting piece 22 is engaged with each recess 12.

On the other hand, each recess 12 is formed in a trapezoidal shape so that the stamped portion receives each projecting piece 22 in the molded recess. Therefore, each recess 12 has a dimensional relationship in which a gap cannot be formed as much as possible in the X direction and the Y direction between the recesses 12 when the projecting pieces 22 are received in the punched recesses. As a result, when the open sides of the first and second open-section sheet metal parts 10 and 20 are opposed to each other and the butt end faces 11a and 21a of the pair of end portions 11 and 21 are brought into contact with each other and joined. Each protrusion 22 engages with each recess 12 and plays the role of a guide, so that both can be joined without deviation in the X direction and the Y direction. Further, since each protrusion 22 is engaged with each recess 12, it is possible to prevent the ends 11 and 21 from being relatively deformed in the Y direction due to the heat of welding for joining. As such, the engagement of each recess 12 with each projecting piece 22 suppresses the relative deformation of the end portions 11 and 21 in the Y direction, and thus the straightening jig required to suppress such deformation. Can be omitted.

<Manufacturing method of one embodiment>
FIGS. 5 to 7 show a manufacturing process of the first open cross-section sheet metal part 10. 8 and 9 show the manufacturing process of the second open-section sheet metal part 20. Further, FIGS. 10 and 11 show a manufacturing process in which the first and second open-section sheet metal parts 10 and 20 are combined and joined to form one closed-section hollow structure 1.

<Manufacturing method of first open-section sheet metal part 10 (first step: pull-out shearing)>
FIG. 5 shows a state of the first step of forming a rectangular semi-finished product 10A to be the first open-section sheet metal part 10 by shearing one steel plate with a press machine (not shown). In this case, the shearing process is performed by punching and shearing with a progressive press. When the pull-out shearing process is performed, the scrap is finely divided. In FIG. 5, the shearing dies A1 to A6 to be sheared are hatched.

First, shearing is performed by the shearing dies A1 and A3, and then shearing is performed by the shearing dies A2 and A4. By these shearing processes, the long side of the rectangular semi-finished product 10A is formed. At this time, the portion corresponding to the recess forming portion 12A, which is the recess 12 described above, is the matching (joint) of the press. Therefore, there is a possibility that burrs may be formed in this part due to the misalignment of the shearing dies A1 and A2 and the misalignment of the shearing dies A3 and A4. Since the processing is performed once by the molds A1 to A4, the generation of burrs is suppressed. Finally, shearing is performed by the shearing dies A5 and A6 to form the short side of the rectangular semi-finished product 10A.

<Manufacturing method of first open cross-section sheet metal part 10 (second step: embossing)>
FIG. 6 shows a state of the second step of forming the concave portion 12 by punching the concave portion forming portion 12A of the above-mentioned semi-finished product 10A with a press machine (not shown).

<Manufacturing method of the first open cross-section sheet metal part 10 (third step: bending process)>
FIG. 7 shows a state of the third step of bending the bent portion 13 shown by the broken line of FIG. 5 to complete the first open cross-section sheet metal part 10 having a U-shaped cross section. At this time, the recess 12 is set to be outside in the bending direction.

<Manufacturing method of the second open-section sheet metal part 20 (first step: pull-out shearing)>
FIG. 8 shows a state of the first step of forming a substantially rectangular semi-finished product 20A to be a second open-section sheet metal part 20 by shearing one steel plate with a press machine (not shown). In this case, as in the case of forming the semi-finished product 10A to be the first open-section sheet metal part 10, the shearing process is performed by pull-out shearing. In FIG. 8, the shearing dies B1 to B6 to be sheared are hatched.

First, shearing is performed by the shearing dies B1 and B3, and then shearing is performed by the shearing dies B2 and B4. By these shearing processes, the long side of the rectangular semi-finished product 20A is formed. At this time, a pair of projecting pieces 22 are also formed on the opposite sides of the central portion of the long side. Further, the portion that becomes the protrusion 22 is considered to be the matching of the press. Therefore, there is a possibility that burrs may be formed in this part due to the misalignment of the shearing dies B1 and B2 and the misalignment of the shearing dies B3 and B4. Since the processing is performed once by the molds B1 to B4, the generation of burrs is suppressed. Finally, shearing is performed by the shearing dies B5 and B6 to form the short side of the rectangular semi-finished product 20A.

<Manufacturing method of the second open cross-section sheet metal part 20 (third step: bending process)>
FIG. 9 shows a state of the third step of bending the bent portion 23 shown by the broken line of FIG. 8 to complete the second open cross-section sheet metal part 20 having a U-shaped cross section. At this time, each projecting piece 22 is made to extend straight from the tip of the pair of end portions 21 formed by bending toward the tip side.

<Manufacturing method of closed cross-section hollow structure 1 (4th step: assembly)>
FIG. 10 shows a fourth step of assembling the first and second open cross-section sheet metal parts 10 and 20 by facing each other on the open sides and abutting the butted end faces 11a and 21a of the pair of end portions 11 and 21 respectively. Show the situation. At this time, the projecting pieces 22 are inserted into the recesses 12 and engaged with each other to play the role of a guide, so that the butt end faces 11a and 21a can come into contact with each other without deviation.

<Manufacturing method of closed cross-section hollow structure 1 (fifth step: welding)>
FIG. 11 shows a fifth step of arc welding and fixing each pair of end portions 11 and 21 of the assembled first and second open cross-section sheet metal parts 10 and 20. At this time, the first and second open-section sheet metal parts 10 and 20 are maintained by the clamps C1 and C2 so as to maintain the assembled state of the first and second open-section sheet metal parts 10 and 20 assembled in the fourth step. Is sandwiched and held. Then, the contact portions of the pair of end portions 11 and 21 of the first and second open cross-section sheet metal parts 10 and 20 held by the clamps C1 and C2 are arced except for the portions of the recess 12 and the protrusion 22. Weld and join. Weld beads 3 are formed at the contact portions of the ends 11 and 21 by arc welding.

With the pair of ends 11 and 21 of the first and second open-section sheet metal parts 10 and 20 in contact with each other, the projecting piece 22 engages with the recess 12 and the pair of ends 11 and 21 come into contact with each other. The deviation is suppressed. Therefore, arc welding can be performed stably. Moreover, since burrs associated with shearing are suppressed between the pair of ends 11 and 21 as described above, the pair of ends 11 and 21 are in good contact with each other, further stabilizing arc welding. Can be done. On the other hand, there may be a gap between the projecting piece 22 and the recess 12 in the engaged state. Therefore, welding is not performed here to prevent the joining from becoming unstable.

<Action and effect of one embodiment>
By engaging the projecting piece 22 and the recess 12 to join the first and second open-section sheet metal parts 10 and 20, the position of the pair of end portions 11 and 21 of the open-section sheet metal parts 10 and 20 is displaced. It can be suppressed and the joining accuracy can be improved. Moreover, since the recess 12 is formed by punching out a part of the end portion 11 of the first open-section sheet metal component 10, it can be easily manufactured by pressing. Further, the projecting piece 22 protruding toward the recess 12 can also be easily manufactured by pressing.

<Other embodiments>
Although the specific embodiments have been described above, the present invention is not limited to their appearance and configuration, and various changes, additions, and deletions are possible. For example, in the above embodiment, the combination of the recess and the projecting piece is formed at the opposite positions of the pair of ends, and two sets of the combination are formed by one closed cross-section hollow structure. However, this combination may be one set in one closed cross-section hollow structure, or may be three or more sets. Further, in the above embodiment, the combination of the two sets is formed at the facing positions of the pair of ends, but it may be formed so as to be offset from the facing positions. Further, in the above embodiment, recesses are formed at each pair of ends of the first open-section sheet metal component, and protrusions are formed at each pair of ends of the second open-section sheet metal component. However, recesses may be formed in one of the pair of ends of each open cross-section sheet metal component, and protrusions may be formed in the other.

In the above embodiment, when the projecting pieces are inserted into the recesses and the two engage with each other, the ends of the first and second open-section sheet metal parts are in the plate surface direction (X direction) and the plate thickness direction (X direction). It was made to suppress the relative movement in the Y direction). However, the suppression of the relative movement between the end portions due to the engagement of the recess and the protrusion may be suppressed only in the plate thickness direction (Y direction).

In the above embodiment, the first and second open-section sheet metal parts are paired with each other. However, although the ends can be joined to each other, they may have different shapes.

In the above embodiment, the shapes of the recesses and the protrusions are trapezoidal. However, these shapes may be a rectangle, a triangle, an arc shape, or the like.

In the above embodiment, the pair of ends of each open-section sheet metal part are joined by arc welding, but they may be joined by welding other than arc welding such as butt welding.

In the above embodiment, the semi-finished products of each open-section sheet metal part are separated when they are formed by shearing, but the semi-finished products may be formed by one shearing without performing the sampling. ..

<Operation and effect of the above-described embodiment corresponding to each invention>
Finally, the effects of the above-described embodiments corresponding to the first and subsequent inventions in the above-mentioned "means for solving the problem" will be added.

According to the first invention, by engaging the projecting piece and the recess to join the first and second open-section sheet metal parts, it is possible to suppress the positional deviation of the pair of ends of each open-section sheet metal part and join them. The accuracy can be improved. Moreover, since the recess is formed by punching out a part of the end portion of the open-section sheet metal part, it can be easily manufactured by pressing. Further, the projecting pieces protruding toward the recesses can also be easily manufactured by pressing.

According to the second invention, since the combination of the recess and the projecting piece is formed at the opposite position of the pair of end portions of each open cross-section sheet metal component, the recess and the projecting piece are both formed between the facing positions of the pair of end portions. Is engaged to adjust the joining position, and the joining accuracy of the first and second open-section sheet metal parts is improved.

According to the third invention, since the recess is formed in the first open-section sheet metal component and the projecting piece is formed in the second open-section sheet metal component, each of the recess and the projecting piece is collectively formed. And can improve productivity.

According to the fourth invention, since the projecting piece is trapezoidal, the tip toward the concave portion is thin, and the insertion work into the concave portion becomes easy. On the contrary, the base end of the projecting piece is thick, and the strength of the projecting piece when engaged with the recess can be increased.

According to the fifth invention, in a state where each pair of ends of the first and second open-section sheet metal parts are in contact with each other, the projecting piece engages with the recess and the pair of ends are suppressed from being displaced. Has been done. Therefore, arc welding can be performed stably. On the other hand, there may be a gap between the protruding piece in the engaged state and the recess. Therefore, welding is not performed here to prevent the joining from becoming unstable.

According to the sixth invention, the projecting piece can be formed without any special work due to the shape of the press die when forming the semi-finished products of the first and second open-section sheet metal parts. Further, the recesses can be easily formed by simple press forming in which the first and second open-section sheet metal parts are punched out in the plate thickness direction.

According to the seventh invention, when performing the pull-out shearing, the portions of the recess and the protrusion are set to match the press. Therefore, burrs during pressing are likely to occur in the recesses and projecting pieces, and are suppressed from occurring in the joints of the first and second open-section sheet metal parts. Therefore, it is possible to improve the joining accuracy of the first and second open-section sheet metal parts without being affected by burrs during shearing, and it is possible to perform punching and shearing in the first step.

1 Closed cross-section hollow structure 2 Closed cross-section hollow part 3 Welded bead 10 First open-section sheet metal part 10A Semi-finished product 20 Second open-section sheet metal part 11, 21 Ends 11a, 21a Butted end face 12 Recess 12A Recess forming part 13 , 23 Folded part 22 Projection pieces A1 to A6, B1 to B6 Shearing dies C1, C2 clamps

Claims (7)

Both open-section sheet metal parts having a U-shaped cross section face each other with their open sides facing each other, and the pair of ends are joined to each other to form a closed cross section between the first and second open-section sheet metal parts. It is a closed cross-section hollow structure in which a hollow portion is formed.
At least one part of the pair of ends of the first or second open cross-section sheet metal part is punched out of the hollow portion of the closed cross section by an amount corresponding to the plate thickness to form a recess.
At the tip of the pair of ends of the first or second open-section sheet metal part, a projecting piece protruding toward the recess is formed at a portion corresponding to the recess.
The projecting pieces are inserted into the recesses and engaged with each other so as to prevent the first and second open-section sheet metal parts from moving relative to each other in the plate thickness direction of the pair of ends. Closed cross section hollow structure. In claim 1,
The combination of the recess and the protrusion is a closed-section hollow structure formed at opposite positions of each pair of ends of the first and second open-section sheet metal parts. In claim 2,
The recess is a closed cross-section hollow structure formed in the first open-section sheet metal component, and the protrusion is formed in the second open-section sheet metal component. In any of claims 1 to 3,
The projecting pieces have a uniform plate thickness, and the shape along the plate surface of the pair of ends of the first or second open-section sheet metal parts is trapezoidal. A hollow structure with a closed cross section whose upper bottom having a short length is on the side facing the recess. In any of claims 1 to 4,
A closed-section hollow structure in which the pair of ends of the first and second open-section sheet metal parts are joined to each other by arc welding at a portion other than the recess and the portion where the protrusion is formed. The method for manufacturing a closed-section hollow structure according to claim 1.
The plate material is sheared by a press to form a semi-finished product to be the first and second open-section sheet metal parts, and the protrusion is attached to each pair of ends of the semi-finished product on the side having the protrusion. The first step in which is formed and
Manufacture of a closed cross-section hollow structure including a second step of forming the recesses by punching out a press in the plate thickness direction for each pair of ends of the semi-finished product on the side provided with the recesses. Method. In claim 6,
The first step is a method for manufacturing a closed-section hollow structure in which the recess and the portion forming the protrusion are set for matching at the time of pressing and shearing is performed.

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