Manufacturing method for floor member

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] FIELD OF THE DISCLOSURE The present disclosure relates to a method for manufacturing a floor member. [Background technology]

[0002] As described in Patent Document 1, a technique is known for manufacturing press-formed products by spot welding a main steel plate and a reinforcing steel plate that are arranged one on top of the other to form an overlapping blank, and by press-forming the overlapping blank. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-199520 Summary of the Invention [Problem 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 so-called hat-shaped, and the reinforcing steel plate is arranged in contact with the inner peripheral surface of the bent portion of the main steel plate. Therefore, when press-forming the overlapped blank, shear force is generated at the joint between the main steel plate and the reinforcing steel plate, which may cause the joint to break.

[0005] In one aspect of the present disclosure, it is desirable to inhibit fracture of the joint. [Means for solving the problem]

[0006] One aspect of the present disclosure is a method for manufacturing a floor member included in a vehicle floor. The manufacturing method includes forming curved beads in multiple bead portions of a main body member, which is a plate-shaped member, so as to protrude from the underside of the main body member, and arranging multiple reinforcing members, which are plate-shaped members thicker than the main body member, so as to cover the upper surfaces of multiple covering portions of the main body member. The manufacturing method also includes welding the main body member and the multiple reinforcing members arranged in the multiple covering portions to form a joint material, and cold press-forming the joint material to form a floor member. The cold press-forming forms lower ridge portions extending along the ridge lines 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 ridge lines. The bead portions are located at or near the lower ridge portions.

[0007] According to the above configuration, when the joining material is cold-press-formed, the bead portion can absorb the elongation that occurs around the lower ridge portion of the main body member, thereby preventing the joining portion between the main body member and the reinforcing member from breaking.

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

[0009] In one embodiment of the present disclosure, at least one of the plurality of bead portions may be provided so as to traverse the covering portion. According to the above configuration, when the joining material is cold-pressed, the bead portion can more effectively absorb the elongation that occurs around the lower ridge portion of the main body member, thereby more effectively preventing the joining portion between the main body member and the reinforcing member from breaking.

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

[0011] [Figure 1] FIG. [Figure 2] 10 is an explanatory view showing the main body member, the upper mold, and the lower mold in the bead forming step, viewed from the longitudinal end side of the main body member. FIG. [Figure 3] FIG. 10 is an explanatory view of the upper surface of the main body member on which the bead is formed. [Figure 4] 10 is an explanatory view of the joining material in the joining step viewed from the longitudinal end side of the main body member. FIG. [Figure 5] 10A and 10B are cross-sectional views of a portion of the bonding material where a reinforcing member is provided, taken perpendicular to the short side direction, and an explanatory view showing an upper mold and a lower mold in a pressing process. [Figure 6] 10 is a cross-sectional view perpendicular to the short side direction of a portion of a bonding material formed in a press process where a reinforcing member is provided, and an explanatory diagram showing an upper mold and a lower mold in the press process. FIG. [Figure 7] FIG. 10 is a cross-sectional view perpendicular to the ridgeline of the lower ridgeline portion. [Figure 8] FIG. 10 is a cross-sectional view perpendicular to the ridgeline of the lower ridgeline portion. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. Floor materials] The floor member 3 of this embodiment is a plate-like member that constitutes the floor of the passenger compartment in the body of the vehicle, and has a generally rectangular shape extending in the longitudinal direction L (see FIGS. 1 and 6). As an example, the floor member 3 has a shape that is symmetrical with respect to a center line C that passes through the center of the longitudinal direction L, and is installed in 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 trunk room of the vehicle.

[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 and lower surfaces of the main body member 1 and the plurality of reinforcing members 2 in the floor member 3 mounted on a vehicle will be referred to as upper surfaces 1U and 2U and lower surfaces 1L and 2L, respectively.

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

[0015] [(2) Reinforcement members] Each reinforcing member 2 is, for example, a substantially rectangular plate-shaped member, and is thicker than the main body member 1 (see FIG. 1). For example, each reinforcing member 2 may be made of a steel plate having a tensile strength higher than that of the main body member 1, the tensile strength of which is 440 MPa or more and 1470 MPa or less. Furthermore, for 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 of the main body member 1 adjacent to an end portion extending in the longitudinal direction L (hereinafter referred to as the longitudinal end portion 12), and protrudes beyond 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 beyond the end portion of the main body member 1 in the short direction S. Furthermore, all or some of the reinforcing members 2 may be arranged so as not to protrude beyond the main body member 1. Hereinafter, the portion of the main body member 1 covered by the reinforcing member 2 will be referred to as the covered portion 11.

[0017] [(3) Inclined section] At least one inclined portion 30 is provided for each reinforcing member 2 (see FIG. 1). Each inclined portion 30 includes a portion of the reinforcing member 2 corresponding to the inclined portion 30 and a portion of the covering portion 11 overlapping the portion of the reinforcing member 2. The inclined portion 30 is provided along a predetermined path 30A and extends in a direction intersecting with a reference plane R in a cross section perpendicular to the path 30A (see FIG. 6). The reference plane R is an imaginary plane perpendicular 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 with the reference plane R at a gentle angle, but the angle at which the inclined portion 30 intersects with the reference plane R can be determined appropriately.

[0018] In this embodiment, as an example, the floor member 3 is formed with a plurality of shallow convex portions that protrude toward the upper surface side, and the inclined portions 30 form the edges of the convex portions. Specifically, as an example, the floor element 3 has four reinforcing elements 2 and four covering elements 11 lined up in the longitudinal direction L. Two inclined elements 30 are provided along a U-shaped (in other words, angular U-shaped) path 30A corresponding to each of the two reinforcing elements 2 located at both ends of the row. Each path 30A corresponding to these inclined elements 30 has two sections whose ends are located at the longitudinal end 12 and which extend straight from the longitudinal end 12 in the short direction S, and one section which extends straight in the longitudinal direction L to connect the ends of these sections. Furthermore, one path 30A is located outside the other path 30A.

[0019] In addition, one inclined portion 30 is provided along a path 30A extending straight in the short-side direction S, corresponding to each of the two centrally located reinforcing members 2. The path 30A extends from the longitudinal end 12 and crosses the reinforcing members 2.

[0020] Of course, the positions and number of the reinforcing members 2, the number of inclined portions 30 corresponding to each reinforcing member 2, and the positions and shapes of the inclined portions 30 can be determined as appropriate. Also, for example, there may be reinforcing members 2 that are not provided with inclined portions 30.

[0021] [2. Manufacturing method of floor components] The floor member 3 is manufactured by patchwork. That is, in the manufacturing process of the floor member 3, the main body member 1 and the multiple reinforcing members 2, which are joined by spot welding, are cold-pressed to form the multiple inclined portions 30. The manufacturing method of the floor member 3 includes a bead forming process, a joining process, and a pressing process (see Figures 2 to 6).

[0022] [(1) Bead forming process] In the bead forming process, cold press forming is performed on the main body member 1, which is a substantially rectangular plate-shaped blank material. As a result, curved beads are formed so as to protrude from the lower surface 1L in a plurality of elongated bead portions 10 predetermined in the main body member 1 (see Figures 2 and 3).

[0023] Specifically, the main body member 1 is placed between an upper mold 40 and a lower mold 41 that are arranged to face each other (see FIG. 2). Then, the upper mold 40 and the lower mold 41 are brought close to each other and pressed against each other while sandwiching the main body member 1, thereby forming a bead from the first end to the second end of each bead portion 10. The positions and orientations at which the upper mold 40 and the lower mold 41 are placed and the method for bringing the upper mold 40 and the lower mold 41 close to each other during cold press forming can be determined as appropriate.

[0024] That is, the position of the covering portion 11 (in other words, the position where the reinforcing member 2 is disposed) and the position of the inclined portion 30 to be formed in the subsequent pressing process are determined in advance in the main body member 1. As described above, as an example, the position of the covering portion 11 is determined so as to be adjacent to the longitudinal end portion 12. Furthermore, the position of the inclined portion 30 corresponding to the covering portion 11 is determined so as to overlap with the covering portion 11.

[0025] Each bead 10 is provided corresponding to an inclined portion 30, in other words, a lower ridge portion 31 (described in detail later) formed in the inclined portion 30 (see FIGS. 1, 6 to 8). The position of each bead 10 is adjusted so that when the lower ridge portion 31 corresponding to the bead 10 is formed in a later pressing process, the bead 10 is located at or near a ridge covered portion 31C included in the lower ridge portion 31. Each bead 10 is located along a path 30A on 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 covered portion 11 (see FIG. 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 aligned in the longitudinal direction L. These bead portions 10 are arranged along each section of the path 30A of the inclined portions 30 extending in the short direction S. Alternatively, for example, bead portions 10 may be provided along a section of the path 30A extending in the longitudinal direction L. Furthermore, one bead portion 10 is provided corresponding to each of the inclined portions 30 provided on 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 portion 12 of the covering portion 11 where the inclined portion 30 corresponding to the bead portion 10 is provided, and reach the outside of the covering portion 11 in the main body member 1.

[0028] Of course, for example, there may be a coating portion 11 in which no bead portion 10 is provided, or a bead portion 10 may be provided in which both ends or one end are located in the coating portion 11 without crossing the coating portion 11.

[0029] [(2) Joining process] In the joining process, a plurality of reinforcing members 2 are placed on the upper surface 1U of the main body member 1 on which a plurality of beads have been formed (see FIG. 4). At this time, each reinforcing member 2 covers a corresponding covering portion 11 at a predetermined position on the main body member 1, and protrudes from the longitudinal end portion 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 bonding material 3A is formed by welding the main body member 1 and each reinforcing member 2. As an example, the bonding material 3A may be formed by spot welding the main body member 1 and each reinforcing member 2 using an upper electrode 42 abutting on the upper surface 2U of the reinforcing member 2 and a lower electrode 43 abutting on the lower surface 1L of the main body member 1. Also, as an example, the vicinity of the end of the reinforcing member 2 is welded to the main body member 1, but the part to be welded is not limited to this and can be determined appropriately.

[0031] [(3) Pressing process] In the pressing step, the joining material 3A is cold-pressed to form a plurality of inclined portions 30. In this way, the floor member 3 is formed from the joining material 3A.

[0032] Specifically, the bonding material 3A is placed between an upper mold 44 and a lower mold 45 that are arranged to face each other (see FIG. 5). Then, the upper mold 44 and the lower mold 45 are brought close to each other and pressed against each other with the bonding material 3A sandwiched therebetween, thereby forming a plurality of inclined portions 30 (see FIG. 6). The positions and orientations at which the upper mold 44 and the lower mold 45 are placed and the method for bringing the upper mold 44 and the lower mold 45 close to each other 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 extending along the ridge line 31A is formed on the edge located on the lower side of each inclined portion 30 (see FIG. 1). The ridge line 31A is located on or near the edge of the inclined portion 30 and extends along the inclined portion 30. The lower ridge portion 31 is a curved portion whose cross section perpendicular to the ridge line 31A protrudes toward the main body member 1 (in other words, downward) (see FIGS. 6 to 8). The lower ridge portion 31 also has a ridge line reinforcing portion 31B that is part of the reinforcing member 2 and a ridge line covering portion 31C that is a portion of the covering portion 11 facing the ridge line reinforcing portion 31B.

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

[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 partial section of the bead portion 10, or may be formed in the entire section. Also, in this embodiment, as an example, a gap G exists between all of the bead portions 10 and the reinforcing member 2. However, this is not limiting, and the beads of all or some of the bead portions 10 may be completely crushed, so that the gap G does not substantially exist.

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

[0038] In contrast, according to the above embodiment, the position of the bead portion 10 of the joining material 3A in the main body member 1 is adjusted so that the bead portion 10 is located at or near the ridge line covering portion 31C of the main body member 1 after cold press forming. This makes it possible to absorb the elongation that occurs around the ridge line covering portion 31C of the main body member 1, thereby making it possible to prevent the joints between the main body member 1 and each reinforcing member 2 from breaking due to cold press forming, and also to prevent delayed fracture of the joints.

[0039] (2) Furthermore, the reinforcing member 2 is disposed so as to protrude from the main body member 1. Therefore, the protruding portion of the reinforcing member 2 can reinforce other members that are adjacent to the floor member 3 and installed in the vehicle.

[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 in the bead portion 10 can more effectively absorb the elongation that occurs around the ridge line covering portion 31C in the main body member 1. Therefore, it is possible to more effectively prevent the joining portion between the main body member 1 and the reinforcing member 2 from breaking.

[0041] (4) A gap G is formed between the bead portion 10 of the floor member 3 and the reinforcing member 2. This improves the rigidity of the area around the bead portion 10 of 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 of the dimensions of the main body member 1 and the reinforcing member 2 can be relaxed, making it easier to manufacture the floor member 3.

[0043] Furthermore, when painting the floor member 3, paint may 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 therefore the ridge line 31A and the bead portion 10 also have a straight shape. However, this is not limiting, and the shapes 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 also have a curved shape according to the shape of the inclined portion 30. Of course, in this case, as in the above embodiment, in the floor member 3, each bead portion 10 is located at or near the ridge line covering portion 31C of the lower ridge line portion 31 corresponding to that bead portion 10.

[0044] (2) Multiple functions of one component in the above embodiments 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. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0045] [5. Technical Ideas Disclosed in the Present Specification] [Item 1] A method for manufacturing a floor member included in a vehicle floor, comprising: forming curved beads on a plurality of bead portions of a main body member that is a plate-like member so as to protrude from a lower surface of the main body member; disposing a plurality of reinforcing members, which are plate-shaped members thicker than the main body member, so as to cover the upper surfaces of the plurality of covering portions of the main body member, respectively; forming a joining material by welding the main body member and the plurality of reinforcing members disposed on the plurality of covering portions; cold press forming the joining material to form the floor member; Equipped with a lower ridge portion extending along a ridge line corresponding to each of the reinforcing members is formed by the cold press forming, and the lower ridge portion is bent 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 the floor member according to item 1, At least one of the plurality of reinforcing members is disposed so as to protrude from the body member. A method for manufacturing floor components.

[0047] [Item 3] A method for manufacturing a floor member according to item 1 or 2, At least one of the plurality of 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 according to any one of items 1 to 3, In the floor member, a gap is formed between at least one of the plurality of 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...transverse direction, G...gap, R...reference plane, C...center line, 1...main body member, 1U...upper surface, 1L...lower surface, 10...bead portion, 11...coating portion, 12...longitudinal end portion, 2...reinforcing member, 2U...upper surface, 2L...lower surface, 3...floor member, 3A...jointing material, 30...inclined portion, 30A...path, 31...lower ridge portion, 31A...ridge, 31B...ridge reinforcement portion, 31C...ridge coating 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 a floor member included in a vehicle floor, comprising: forming curved beads on a plurality of bead portions of a main body member that is a plate-like member so as to protrude from a lower surface of the main body member; disposing a plurality of reinforcing members, which are plate-shaped members thicker than the main body member, so as to cover the upper surfaces of the plurality of covering portions of the main body member, respectively; forming a joining material by welding the main body member and the plurality of reinforcing members disposed on the plurality of covering portions; cold press forming the joining material to form the floor member; Equipped with a lower ridge portion extending along a ridge line corresponding to each of the reinforcing members is formed by the cold press forming, and the lower ridge portion is bent 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.

2. 2. A method for manufacturing a floor element according to claim 1, comprising: At least one of the plurality of reinforcing members is disposed so as to protrude from the body member. A method for manufacturing floor components.

3. A method for manufacturing a floor member according to claim 1 or claim 2, At least one of the plurality of bead portions is provided so as to traverse the covering portion. A method for manufacturing floor components.

4. A method for manufacturing a floor member according to claim 1 or claim 2, In the floor member, a gap is formed between at least one of the plurality of bead portions of the main body member and the reinforcing member. A method for manufacturing floor components.

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