Floor component manufacturing method

Abstract

To prevent breakage of a joint part.SOLUTION: A manufacturing method for a floor member of a vehicle includes: forming beads in a plurality of bead portions in a body member; disposing a plurality of reinforcing members in a plurality of covering portions in the body member; forming a joining material by welding the body member and the plurality of reinforcing members; and performing cold press forming on the joining material. A lower ridge line portion extending along a ridge line is formed in correspondence with each reinforcing member by the cold press forming. The lower ridge line portion is bent so as to protrude toward the main body member in a cross section orthogonal to the ridge line. The bead portions are located at the lower ridge portion or in the vicinity of the lower ridge portion.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a floor member.

Background Art

[0002] As described in Patent Document 1, a technique for manufacturing a press-formed product is known, in which a stacked blank is formed by joining a main body steel plate and a reinforcing steel plate arranged in a stacked manner by spot welding, and the stacked blank is press-formed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the cross-section of the press-formed product manufactured by the technique of Patent Document 1 is a so-called hat shape, and the reinforcing steel plate is arranged in a state of abutting against the inner peripheral surface at the bending portion of the main body steel plate. Therefore, when the stacked blank is press-formed, a shearing force is generated at the joint portion between the main body steel plate and the reinforcing steel plate, and there is a risk that the joint portion breaks.

[0005] In one aspect of the present disclosure, it is desirable to suppress the breakage of the joint portion.

Means for Solving the Problems

[0006] One aspect of this disclosure is a method for manufacturing a floor member included in the floor of a vehicle. The manufacturing method comprises forming beaded portions on a main body member, which is a plate-shaped member, that are curved so as to protrude from the lower surface of the main body member, and arranging a plurality of reinforcing members, which are plate-shaped members thicker than the main body member, so as to cover the upper surfaces of a plurality of covering portions on the main body member. The manufacturing method also comprises forming a joint by welding the main body member and the plurality of reinforcing members arranged on the plurality of covering portions, and forming a floor member by cold press forming the joint. Cold press forming forms lower ridge portions that extend along the ridges corresponding to each reinforcing member. The lower ridge portions are curved so as to protrude toward the main body member in a cross section perpendicular to the ridges. The bead portions are located on or near the lower ridge portions.

[0007] According to the above configuration, when cold press forming is performed on the joining material, the bead portion can absorb the elongation that occurs around the lower ridge of the main member. Therefore, it is possible to suppress fracture at the joint between the main member and the reinforcing member.

[0008] In one aspect of this disclosure, at least one of the multiple reinforcing members may be arranged to protrude from the main body member. According to the above configuration, the reinforcing members that protrude from the main body can reinforce other members.

[0009] In one aspect of this disclosure, at least one of the multiple bead portions may be provided so as to traverse the coating portion. According to the above configuration, when cold press forming is performed on the joining material, the bead portion can more effectively absorb the elongation that occurs around the lower ridge of the main body member. Therefore, fracture at the joint between the main body member and the reinforcing member can be more effectively suppressed.

[0010] In one aspect of the present disclosure, a gap may be formed between at least one of the plurality of bead portions in the main body member and the reinforcing member in the floor member. According to the above configuration, the rigidity around the bead portion of the floor member can be improved. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view of the flooring material. [Figure 2] This is an explanatory diagram showing the main body member, upper mold, and lower mold in the bead formation process, viewed from the longitudinal end side of the main body member. [Figure 3] This is an explanatory diagram of the upper surface of the main body member on which the bead has been formed. [Figure 4] This is an explanatory diagram showing the joining material in the joining process, viewed from the longitudinal end side of the main component. [Figure 5] This diagram shows a cross-sectional view perpendicular to the short direction of the portion of the joining material where a reinforcing member is provided, and an explanatory diagram showing the upper and lower dies of the pressing process. [Figure 6] This diagram shows a cross-sectional view perpendicular to the short direction of the portion of the joint material formed in the pressing process where a reinforcing member is provided, and an explanatory diagram showing the upper and lower dies of the pressing process. [Figure 7] This is a cross-sectional view perpendicular to the ridge of the lower ridge. [Figure 8] This is a cross-sectional view perpendicular to the ridge of the lower ridge. [Modes for carrying out the invention]

[0012] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. Flooring materials] The floor member 3 in this embodiment is a plate-shaped member that constitutes the floor of the passenger compartment in the vehicle body, and has a substantially rectangular shape extending in the longitudinal direction L (see Figures 1 and 6). As an example, the floor member 3 has a shape that is symmetrical with respect to a center line C passing through the center of the longitudinal direction L, and is mounted on the vehicle with the longitudinal direction L coinciding with the vehicle width direction. Of course, the shape of the floor member 3 can be determined as appropriate. Furthermore, the floor member 3 may be, for example, a member included in the floor of the vehicle's trunk compartment.

[0013] The floor member 3 includes a main body member 1, a plurality of reinforcing members 2, and a plurality of inclined portions 30. Hereinafter, the upper surface and the lower surface of the main body member 1 and the plurality of reinforcing members 2 in the floor member 3 mounted on the vehicle are respectively described as the upper surfaces 1U, 2U and the lower surfaces 1L, 2L.

[0014] [(1) Main body member] The main body member 1 is, for example, a substantially rectangular plate-like member extending in the longitudinal direction L (see FIG. 1). As an example, the main body member 1 may be made of a steel plate having a tensile strength of 440 MPa or less. Also, as an example, the thickness of the main body member 1 may be 0.5 mm or more and 1.0 mm or less.

[0015] [(2) Reinforcing member] Each reinforcing member 2 is, for example, a substantially rectangular plate-like member and is thicker than the main body member 1 (see FIG. 1). As an example, each reinforcing member 2 may have a higher tensile strength than the main body member 1 and may be made of a steel plate having a tensile strength of 440 MPa or more and 1470 MPa or less. Also, as an example, the thickness of each reinforcing member 2 may be 1.0 mm or more and 1.8 mm or less.

[0016] Each reinforcing member 2 is joined to the upper surface 1U of the main body member 1 for reinforcement. Each reinforcing member 2 covers a portion adjacent to the end portion (hereinafter, the longitudinal end portion 12) extending in the longitudinal direction L of the main body member 1 and protrudes from the longitudinal end portion 12. Of course, the position of the reinforcing member 2 can be determined appropriately, and the reinforcing member 2 may be arranged, for example, so as to protrude from the end portion in the short side direction S of the main body member 1. Also, all or some of the reinforcing members 2 may be arranged so as not to protrude from the main body member 1. Hereinafter, the portion of the main body member 1 covered by the reinforcing member 2 is described as the covered portion 11.

[0017] [(3) Inclined portion] The inclined portions 30 are provided at least one by one corresponding to each reinforcing member 2 (see FIG. 1). The inclined portion 30 has a part of the reinforcing member 2 corresponding to the inclined portion 30 and a part of the covering portion 11 overlapping with a part of the reinforcing member 2. The inclined portion 30 is provided along a predetermined path 30A, and in a cross section orthogonal to the path 30A, it extends in a direction intersecting with the reference plane R (see FIG. 6). The reference plane R is a virtual plane orthogonal to the direction in which the reinforcing member 2 and the main body member 1 face each other, and extends along the longitudinal direction L and the lateral direction S. As an example, the inclined portion 30 intersects the reference plane R at a gentle angle, but the angle at which the inclined portion 30 intersects the reference plane R is determined as appropriate.

[0018] In this embodiment, as an example, a plurality of shallow convex portions protruding toward the upper surface side are formed on the floor member 3, and the inclined portion 30 forms the edge portions of the convex portions. Specifically, as an example, the floor member 3 has four reinforcing members 2 and four covering portions 11 arranged in the longitudinal direction L. Corresponding to each of the two reinforcing members 2 located at both ends of the row, two inclined portions 30 along a U-shaped (in other words, angular U-shaped) path 30A are provided. Each path 30A corresponding to these inclined portions 30 has two sections whose both ends are located at the longitudinal end portions 12 and extend straight in the lateral direction S from the longitudinal end portions 12, and one section extending straight in the longitudinal direction L so as to connect the end portions of these sections. Still, one path 30A is located outside the other path 30A.

[0019] Also, corresponding to each of the two reinforcing members 2 located at the center, one inclined portion 30 along a path 30A extending straight in the lateral direction S is provided. The path 30A extends from the longitudinal end portion 12 and crosses the reinforcing member 2.

[0020] Of course, the position and number of the reinforcing members 2, the number of inclined portions 30 corresponding to each reinforcing member 2, and the position and shape of the inclined portions 30 can be determined as appropriate. Also, for example, there may be a reinforcing member 2 provided without an inclined portion 30.

[0021] [2. Manufacturing method of floor member] The floor member 3 is manufactured by patchwork. In other words, in the manufacturing process of the floor member 3, multiple inclined sections 30 are formed by cold press forming on the main body member 1 and multiple reinforcing members 2, which are joined by spot welding. The manufacturing method of the floor member 3 includes a bead formation step, a joining step, and a pressing step (see Figures 2-6).

[0022] [(1) Bead formation process] In the bead formation process, the main body member 1, which is a roughly rectangular plate-shaped blank material, is subjected to cold press forming. As a result, multiple elongated bead sections 10 predetermined on the main body member 1 are formed, with curved beads protruding from the lower surface 1L (see Figures 2 and 3).

[0023] Specifically, the main body member 1 is placed between the upper die 40 and the lower die 41, which are positioned facing each other (see Figure 2). Then, the upper die 40 and the lower die 41 are brought closer together and pressed together with the main body member 1 in between, forming a bead from the first end to the second end of each bead portion 10. The position and orientation of the upper die 40 and the lower die 41, and the method of bringing the upper die 40 and the lower die 41 closer together during cold press forming, can be determined as appropriate.

[0024] In other words, the main body member 1 has predetermined positions for the covering portion 11 (in other words, the position where the reinforcing member 2 is placed) and the inclined portion 30 formed in a later pressing process. As described above, as an example, the position of the covering portion 11 is determined to be adjacent to the longitudinal end 12. Also, the position of the inclined portion 30 corresponding to the covering portion 11 is determined to overlap with the covering portion 11.

[0025] Each bead portion 10 is provided in correspondence with the inclined portion 30, or in other words, the lower ridge portion 31 (details will be described later) formed on the inclined portion 30 (see Figures 1, 6-8). The position of each bead portion 10 is adjusted so that when the lower ridge portion 31 corresponding to the bead portion 10 is formed in a later pressing process, the bead portion 10 is located on or near the ridge covering portion 31C included in the lower ridge portion 31. Each bead portion 10 is located along the path 30A through which the corresponding inclined portion 30 is provided, more specifically along the ridge 31A of the corresponding lower ridge portion 31, and the inclined portion 30 crosses the corresponding covering portion 11 (see Figure 3).

[0026] In this embodiment, as an example, four bead portions 10 are provided corresponding to the two inclined portions 30 of each reinforcing member 2 located at both ends of a row arranged in the longitudinal direction L. These bead portions 10 are arranged along each section extending in the short direction S of the path 30A of the inclined portion 30. In addition, for example, bead portions 10 may be provided along sections extending in the longitudinal direction L of the path 30A. Furthermore, one bead portion 10 is provided corresponding to the inclined portions 30 provided on each of the two reinforcing members 2 located in the center of the row.

[0027] These bead portions 10 extend straight in the short direction S from the longitudinal end 12 of the covering portion 11, which is provided with an inclined portion 30 corresponding to the bead portion 10, and reach the outside of the covering portion 11 on the main body member 1.

[0028] Of course, for example, there may be a covering portion 11 that does not have a bead portion 10, or there may be a bead portion 10 that does not cross the covering portion 11 but has both ends or one end located in the covering portion 11.

[0029] [(2) Bonding process] In the joining process, multiple reinforcing members 2 are placed on the upper surface 1U of the main body member 1, where multiple beads have been formed (see Figure 4). At this time, each reinforcing member 2 covers each covering portion 11 at a predetermined position on the main body member 1, and extends beyond the longitudinal end 12. Each covering portion 11 is provided with at least one bead portion 10, and a gap G is formed between the bead portion 10 and the lower surface 2L of each reinforcing member 2.

[0030] Then, the joint material 3A is formed by welding the main body member 1 and each reinforcing member 2. For example, the joint material 3A may be formed by spot welding the main body member 1 and each reinforcing member 2 using an upper electrode 42 that abuts the upper surface 2U of the reinforcing member 2 and a lower electrode 43 that abuts the lower surface 1L of the main body member 1. Also, for example, the vicinity of the end of the reinforcing member 2 is welded to the main body member 1, but the welded portion is not limited to this and can be determined as appropriate.

[0031] [(3) Pressing process] In the pressing process, cold press forming is performed on the joining material 3A to form multiple inclined sections 30. This forms the floor member 3 from the joining material 3A.

[0032] Specifically, a bonding material 3A is placed between the upper die 44 and the lower die 45, which are positioned facing each other (see Figure 5). Then, the upper die 44 and the lower die 45 are brought closer together and pressed together with the bonding material 3A in between to form multiple inclined sections 30 (see Figure 6). The position and orientation of the upper die 44 and the lower die 45, and the method of bringing the upper die 44 and the lower die 45 closer together during cold press forming, can be determined as appropriate.

[0033] As described above, each inclined portion 30 is formed along a predetermined path 30A, and the main body member 1 is provided with a bead portion 10 along each path 30A. Therefore, each inclined portion 30 is formed along the bead portion 10.

[0034] Furthermore, a lower ridge portion 31 is formed on the edge located below each inclined portion 30, extending along the ridge line 31A (see Figure 1). The ridge line 31A is located at or near the edge of the inclined portion 30 and extends along the inclined portion 30. The lower ridge portion 31 is a portion that is curved so that its cross section perpendicular to the ridge line 31A protrudes toward the main body member 1 side (in other words, the downward side) (see Figures 6-8). The lower ridge portion 31 also has a ridge reinforcement portion 31B which is part of the reinforcing member 2, and a ridge covering portion 31C which is the portion of the covering portion 11 that faces the ridge reinforcement portion 31B.

[0035] In the floor member 3, each bead portion 10 is located on or near the ridge covering portion 31C of the lower ridge portion 31 corresponding to the bead portion 10. In other words, the ridge covering portion 31C may include all or part of the bead portion 10. Also, the bead portion 10 may be located at a position away from the ridge covering portion 31C in the inclined portion 30, or in a portion of the main body member 1 other than the inclined portion 30. Furthermore, when each inclined portion 30 is formed by press molding, the bead portion 10 is stretched and the bead is crushed. As a result, the gap G between each bead portion 10 and the reinforcing member 2 is reduced.

[0036] In this embodiment, as an example, a gap G remains between at least one bead portion 10 and the reinforcing member 2. The gap G may exist in a portion of the bead portion 10 or may be formed throughout the entire portion. Also, in this embodiment, as an example, a gap G exists between all bead portions 10 and the reinforcing member 2. However, this is not limited to this, and all or some of the bead portions 10 may have their beads completely crushed, to the point where the gap G is substantially eliminated.

[0037] [3. Effects] (1) In the curve formed by the cross section perpendicular to the ridge 31A in the lower ridge portion 31 of the floor member 3, the ridge covering portion 31C is located inside the ridge reinforcing portion 31B. For this reason, the perimeter of the ridge covering portion 31C is longer than that of the ridge reinforcing portion 31B. The perimeter refers to the length from the first end to the second end along the upper or lower surface of the ridge covering portion 31C or the ridge reinforcing portion 31B in the cross section. For this reason, when forming the inclined portion 30 in the joining material 3A by cold press forming, shear force is generated at the joint between each reinforcing member 2 and the main body member 1, and there is a risk that the joint may break.

[0038] In contrast, according to the above embodiment, the position of the bead portion 10 of the joining material 3A on the main body member 1 is adjusted so that the bead portion 10 is located on or near the ridge line covering portion 31C of the main body member 1 after cold press forming. Therefore, elongation occurring around the ridge line covering portion 31C of the main body member 1 can be absorbed, thereby suppressing fracture of the joint between the main body member 1 and each reinforcing member 2 due to cold press forming, and also suppressing delayed fracture of the joint.

[0039] (2) Furthermore, the reinforcing member 2 is positioned to protrude from the main body member 1. As a result, the protruding portion of the reinforcing member 2 can reinforce other members mounted on the vehicle adjacent to the floor member 3.

[0040] (3) Furthermore, the bead portion 10 is provided so as to cross the covering portion 11. Therefore, when cold press forming is performed on the joining material 3A, the bead formed on the bead portion 10 can more effectively absorb the elongation that occurs around the ridge covering portion 31C of the main body member 1. Therefore, fracture of the joint between the main body member 1 and the reinforcing member 2 can be more effectively suppressed.

[0041] (4) Furthermore, a gap G is formed between the bead portion 10 and the reinforcing member 2 in the floor member 3. This makes it possible to improve the rigidity around the bead portion 10 in the floor member 3.

[0042] Furthermore, by allowing a gap G to occur between the bead portion 10 and the reinforcing member 2, the precision requirements for the dimensions of the main body member 1 and the reinforcing member 2 can be relaxed, making the manufacturing of the floor member 3 easier.

[0043] Furthermore, when painting the floor member 3, paint can flow into the gap G between the bead portion 10 and the reinforcing member 2. This effectively prevents rust. [4. Other Embodiments] (1) In the above embodiment, the inclined portion 30 is provided along a straight path 30A, and accordingly, the ridge line 31A and the bead portion 10 also have a straight shape. However, the shape of the inclined portion 30 and the path 30A can be determined as appropriate, and the inclined portion 30 and the path 30A may have a curved shape. In this case, the ridge line 31A and the bead portion 10 will also have a curved shape according to the shape of the inclined portion 30. Of course, even in this case, in the floor member 3, as in the above embodiment, each bead portion 10 is located on the ridge line covering portion 31C of the lower ridge line portion 31 corresponding to the bead portion 10, or near the ridge line covering portion 31C.

[0044] (2) Multiple functions of one component in the above embodiment may be realized by multiple components, or one function of one component may be realized by multiple components. Also, multiple functions of multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Furthermore, some of the configurations of the above embodiment may be omitted. Also, at least some of the configurations of the above embodiment may be added to or replaced with the configurations of other above embodiments.

[0045] [5. The technical concept disclosed herein] [Item 1] A method for manufacturing floor components included in the floor of a vehicle, In the main body member, which is a plate-shaped member, a curved bead is formed in multiple bead portions so as to protrude from the lower surface of the main body member, Multiple reinforcing members, which are plate-shaped members thicker than the main body member, are arranged so as to cover the upper surfaces of each of the multiple covering portions of the main body member. A joint is formed by welding the main body member and the multiple reinforcing members arranged on the multiple covering portions. The floor member is formed by cold press forming the aforementioned joining material, Equipped with, By the cold press forming described above, a lower ridge portion is formed corresponding to each of the reinforcing members, extending along the ridge line, and the lower ridge portion is curved so as to protrude toward the main body member in a cross section perpendicular to the ridge line. The bead portion is located on or near the lower ridge portion. A method for manufacturing floor components.

[0046] [Item 2] A method for manufacturing floor members as described in item 1, At least one of the multiple reinforcing members is arranged to protrude from the main body member. A method for manufacturing floor components.

[0047] [Item 3] A method for manufacturing a floor member as described in item 1 or item 2, At least one of the multiple bead portions is provided so as to traverse the covering portion. A method for manufacturing floor components.

[0048] [Item 4] A method for manufacturing a floor member as described in any one of items 1 to 3, In the floor member, a gap is formed between at least one of the multiple bead portions in the main body member and the reinforcing member. A method for manufacturing floor components. [Explanation of Symbols]

[0049] L...longitudinal direction, S...short direction, G...gap, R...reference plane, C...center line, 1...main body member, 1U...top surface, 1L...bottom surface, 10...bead portion, 11...covering portion, 12...longitudinal end, 2...reinforcement member, 2U...top surface, 2L...bottom surface, 3...floor member, 3A...jointing material, 30...inclined portion, 30A...path, 31...lower ridge portion, 31A...ridge, 31B...ridge reinforcement portion, 31C...ridge covering portion, 40...upper mold, 41...lower mold, 42...upper electrode, 43...lower electrode, 44...upper mold, 45...lower mold.

Claims

1. A method for manufacturing floor members included in the floor of a vehicle, In the main body member, which is a plate-shaped member, a curved bead is formed in multiple bead portions so as to protrude from the lower surface of the main body member, Multiple reinforcing members, which are plate-shaped members thicker than the main body member, are arranged so as to cover the upper surfaces of each of the multiple covering portions of the main body member. A joint is formed by welding the main body member and the multiple reinforcing members arranged on the multiple covering portions. The floor member is formed by cold press forming the aforementioned joining material, Equipped with, By the cold press forming described above, a lower ridge portion is formed corresponding to each of the reinforcing members, extending along the ridge line, and the lower ridge portion is curved so as to protrude toward the main body member in a cross section perpendicular to the ridge line. The bead portion is located on or near the lower ridge portion. At least one of the multiple bead portions is provided so as to traverse the covering portion. A method for manufacturing floor components.

2. A method for manufacturing floor members included in the floor of a vehicle, In the main body member, which is a plate-shaped member, a curved bead is formed in multiple bead portions so as to protrude from the lower surface of the main body member, Multiple reinforcing members, which are plate-shaped members thicker than the main body member, are arranged so as to cover the upper surfaces of each of the multiple covering portions of the main body member. A joint is formed by welding the main body member and the multiple reinforcing members arranged on the multiple covering portions. The floor member is formed by cold press forming the aforementioned joining material, Equipped with, By the cold press forming described above, a lower ridge portion is formed corresponding to each of the reinforcing members, extending along the ridge line, and the lower ridge portion is curved so as to protrude toward the main body member in a cross section perpendicular to the ridge line. The bead portion is located on or near the lower ridge portion. In the floor member, a gap is formed between at least one of the multiple bead portions in the main body member and the reinforcing member. A method for manufacturing floor components.

3. A method for manufacturing floor members included in the floor of a vehicle, In the main body member, which is a plate-shaped member, a curved bead is formed in multiple bead portions so as to protrude from the lower surface of the main body member, Multiple reinforcing members, which are plate-shaped members thicker than the main body member, are arranged so as to cover the upper surfaces of each of the multiple covering portions of the main body member. A joint is formed by welding the main body member and the multiple reinforcing members arranged on the multiple covering portions. The floor member is formed by cold press forming the aforementioned joining material, Equipped with, By the cold press forming described above, a lower ridge portion is formed corresponding to each of the reinforcing members, extending along the ridge line, and the lower ridge portion is curved so as to protrude toward the main body member in a cross section perpendicular to the ridge line. The bead portion is located on or near the lower ridge portion. At least one of the multiple reinforcing members is arranged to protrude from the main body member. A method for manufacturing floor components.

4. A method for manufacturing a floor member according to claim 1 or claim 2, At least one of the multiple reinforcing members is arranged to protrude from the main body member. A method for manufacturing floor components.

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