Vehicle body lower part structure

Abstract

To expand a space for disposing a power supply unit below a floor panel, in a vehicle width direction and toward the floor panel side, while increasing rigidity of the floor panel.SOLUTION: There is provided a vehicle body lower part structure 1 including a floor panel 10 disposed above a power supply unit B in a vehicle body lower part. In the vehicle body lower part structure 1, the floor panel 10 has: a raised part 13 which is raised toward a vehicle upper side; and a flat part 14 which surrounds the periphery of the raised part 13. The raised part 13 has: a rim bead 13a which forms an outer edge part of the raised part 13 and projects toward the vehicle upper side; and a downward bulging part 13b which forms a part inside the rim bead 13a in the raised part 13 and bulges toward a vehicle lower side.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a vehicle underbody structure. [Background technology]

[0002] If a floor panel disposed under the vehicle body vibrates while the vehicle is traveling, noise may be generated inside the vehicle cabin. Therefore, in order to suppress the vibration of the floor panel, a structure for increasing the rigidity of the floor panel is often applied to the vehicle underbody structure.

[0003] As an example of a vehicle underbody structure having a structure for increasing the rigidity of a floor panel, the structure disclosed in Patent Document 1 is known. The structure disclosed in Patent Document 1 has a floor panel forming the floor surface of the vehicle, a floor side member joined to the lower surface of the floor panel, extending in the front-rear direction of the vehicle and protruding downward, and a floor cross member joined to the upper surface of the floor panel, extending in the vehicle width direction and protruding upward, and the floor panel is formed with a sunken portion that protrudes downward. Thus, in the structure disclosed in Patent Document 1, the sunken portion that protrudes downward and the floor side member that similarly protrudes downward and has a relatively large cross section are provided as part of the structure for increasing the rigidity of the floor panel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-3687 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, with the recent trend toward electrification of vehicles (EVs), power supply units including battery packs may be disposed under the floor panel. In this case, from the viewpoint of ensuring the minimum ground clearance required for the vehicle, it is required that the power supply unit be disposed as close as possible to the underside of the floor panel, and further, as the power supply unit becomes larger, it may be required to secure space for disposing the large power supply unit below the floor panel. However, in the structure disclosed in Patent Document 1, the floor side members and the sunken portion protrude downward from the floor panel, so there is room for improvement in meeting the above requirements.

[0006] Therefore, an object of the present invention is to provide a vehicle underbody structure that can increase the rigidity of the floor panel while expanding the space for arranging a power supply unit below the floor panel in the vehicle width direction and toward the floor panel. [Means for solving the problem]

[0007] In order to achieve the above object, according to one aspect of the present invention, there is provided a vehicle underbody structure including a floor panel arranged above a power supply unit in the underside of the vehicle body, wherein the floor panel has a raised portion that is raised above the vehicle and a flat portion that surrounds the periphery of the raised portion, the raised portion having an edge bead that forms an outer edge of the raised portion and protrudes above the vehicle, and a lower bulge that forms an inner portion of the raised portion relative to the edge bead and bulges below the vehicle. Effect of the Invention

[0008] According to one aspect of the present invention, a vehicle underbody structure can be provided that has a structure that increases the rigidity of the floor panel while enabling the space for placing a power supply unit below the floor panel to be expanded in the vehicle width direction and toward the floor panel. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view of a vehicle underbody structure according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an enlarged top view of a main portion of the vehicle underbody structure. [Diagram 3] FIG. [Figure 4] 3 is a cross-sectional view taken along line AA shown in FIG. 2. [Diagram 5] 3 is a cross-sectional view taken along line BB shown in FIG. 2. [Figure 6] 3 is a partial perspective view of a cut model taken along line CC shown in FIG. 2. [Figure 7] FIG. 4 is a perspective view for explaining the shape of a floor panel in a main portion of FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view of a vehicle body underbody structure 1 according to an embodiment of the present invention, Figs. 2 and 3 are views showing a main part of the vehicle body underbody structure 1, Fig. 2 is an enlarged top view, and Fig. 3 is a perspective view. In the drawings, the arrow Fr direction indicates the front in the vehicle longitudinal direction, the arrow O direction indicates the outside of the vehicle in the vehicle width direction, and the arrow U direction indicates the upper side in the vehicle vertical direction. In the following description, "front" and "rear" correspond to the front and rear in the vehicle longitudinal direction, "up" and "down" correspond to the up and down in the vehicle vertical direction, and "left" and "right" correspond to the left and right in the vehicle width direction when a passenger in the vehicle faces the front of the vehicle.

[0011] (Outline of the underbody structure) Referring to Fig. 1, the vehicle body understructure 1 includes a floor panel 10. A floor tunnel 20 is provided in the center (middle) of the floor panel 10 in the vehicle width direction. In this embodiment, the vehicle body understructure 1 further includes a side sill 30, a first floor cross member 40, and a second floor cross member 50. The vehicle body understructure 1 of this embodiment is applied to the structure of the vehicle underbody of an electric vehicle driven by a power supply unit B (see Figs. 4 to 6 described later) including a battery pack.

[0012] The floor panel 10 is a panel member that constitutes the floor portion of the lower part of the vehicle body, and may also be called a main floor panel. In the illustrated example, the floor panel 10 is a plate-shaped member that extends from the lower part of the front part of the passenger compartment toward the rear of the vehicle. The dimension of the floor panel 10 in the vehicle width direction approximately corresponds to the dimension of the vehicle body in the vehicle width direction. Note that in the vehicle body underbody structure 1, no member equivalent to the floor side member of a conventional vehicle body underbody structure is provided on the underside of the floor panel 10.

[0013] The floor tunnel 20 is provided in the center (middle) of the floor panel 10 in the vehicle width direction. The floor tunnel 20 bulges out toward the top of the vehicle and extends in the vehicle front-rear direction. The floor tunnel 20 extends from the lower part of the front of the vehicle compartment through the first floor cross member 40 and the second floor cross member 50 to the rear of the second floor cross member 50.

[0014] In the illustrated example, the floor tunnel 20 is formed of a separate member from the floor panel 10. The floor tunnel 20 has a hat-shaped cross section that opens downward when viewed in the vehicle longitudinal direction. The floor tunnel 20 is joined to the opening edge portion 11 of the floor panel 10 so as to close from below the opening that is provided in the center of the floor panel 10 in the vehicle width direction and extends in the vehicle longitudinal direction. Specifically, the floor tunnel 20 has a tunnel bulge portion 21 that bulges outward in a roughly trapezoidal shape toward the upper side of the vehicle. A tunnel flange portion 22 that protrudes outward in the vehicle width direction is provided at the lower end of the side wall of the tunnel bulge portion 21. The tunnel flange portion 22 is joined to the lower surface of the opening edge portion 11 of the floor panel 10 by spot welding or the like.

[0015] The side sill 30 is provided on the outer edge of the floor panel 10 in the vehicle width direction and extends in the front-rear direction of the vehicle. A side sill bulge 31 bulging inward in the vehicle width direction is provided in the middle of the side sill 30 in the vehicle up-down direction, as shown in FIG. 4 described later. The side sill bulge 31 is composed of an inner wall 31a facing the inner side in the vehicle width direction, an upper wall 31b extending outward in the vehicle width direction from the upper end of the inner wall 31a, and a lower wall 31c (see FIG. 4 described later) extending outward in the vehicle width direction from the lower end of the inner wall 31a. The outer surface of the vertical flange 12 at the outer edge in the vehicle width direction of the floor panel 10 is joined to the inner wall 31a in the vehicle width direction of the side sill bulge 31 by spot welding or the like.

[0016] The first floor cross member 40 is a member that is joined to the floor panel 10, protrudes upward from the vehicle, and extends in the vehicle width direction. The first floor cross member 40 intersects with the floor tunnel 20 from above, and is joined to the floor tunnel 20 and the floor panel 10.

[0017] The second floor cross member 50 is a member that is joined to the floor panel 10 at a position spaced apart from the first floor cross member 40 in the fore-and-aft direction of the vehicle, and protrudes upward from the vehicle and extends in the vehicle width direction. Similar to the first floor cross member 40, the second floor cross member 50 intersects with the floor tunnel 20 from above and is joined to the floor tunnel 20 and the floor panel 10. In the illustrated example, the second floor cross member 50 is spaced apart from the first floor cross member 40 toward the rear of the vehicle.

[0018] Each of the floor cross members (40, 50) has a hat-shaped cross section that opens downward when viewed in the vehicle front-rear direction. A middle portion of each of the floor cross members (40, 50) in the vehicle width direction is bent to fit along the floor tunnel 20.

[0019] The first floor cross member 40 has a first bulging portion 41, a first front flange 42, a first rear flange 43, and a first outer joint portion 44. The second floor cross member 50 has a second bulging portion 51, a second front flange 52, a second rear flange 53, and a second outer joint portion 54.

[0020] The first bulging portion 41 bulges upward of the vehicle and extends from the right side sill 30 to the left side sill 30. The first front flange 42 extends forward from the lower end of the front wall of the first bulging portion 41, and the first rear flange 43 extends rearward from the lower end of the rear wall of the first bulging portion 41, and each flange (42, 43) is joined to the upper surface of the floor panel 10 by spot welding or the like. The first outer joint portion 44 is a portion that constitutes the end portion of the first floor cross member 40 in the vehicle width direction (longitudinal direction), and is joined to the side sill bulging portion 31 of the side sill 30 by spot welding or the like. The first outer joint portion 44 extends continuously to the top surface portion and the side wall portion of the first bulging portion 41, extends in the cross member width direction (vehicle front-rear direction), and is formed so as to follow the upper portion of the inner wall 31a and the upper wall 31b of the side sill bulging portion 31.

[0021] The second bulging portion 51 bulges upward of the vehicle and extends from the right side sill 30 to the left side sill 30. The second front flange 52 extends forward from the lower end of the front wall of the second bulging portion 51, and the second rear flange 53 extends rearward from the lower end of the rear wall of the second bulging portion 51, and each flange (52, 53) is joined to the upper surface of the floor panel 10 by spot welding or the like. The second outer joint portion 54 is a portion that constitutes the end portion of the second floor cross member 50 in the vehicle width direction (longitudinal direction), and is joined to the side sill bulging portion 31 of the side sill 30 by spot welding or the like. The second outer joint portion 54 extends continuously to the top surface portion and the side wall portion of the second bulging portion 51, extends in the cross member width direction (vehicle front-rear direction), and is formed so as to follow the upper portion of the inner wall 31a and the upper wall 31b of the side sill bulging portion 31.

[0022] Here, the floor panel 10 is divided into a plurality of sections (1R1, 1R2, 1R3, 1L1, 1L2, 1L3) by the floor tunnel 20, the side sill 30, the first floor cross member 40, and the second floor cross member 50. In other words, the floor panel 10 is divided into a plurality of sections (1R1, 1R2, 1R3, 1L1, 1L2, 1L3) in a plan view seen from above the vehicle by a plurality of high-strength members (20, 30, 40, 50) extending vertically and horizontally that constitute the framework members of the lower part of the vehicle body. In the illustrated example, the floor panel 10 is divided (segmented) into six sections (1R1, 1R2, 1R3, 1L1, 1L2, 1L3).

[0023] In the following, the three right-hand compartments of the six compartments will be appropriately referred to as, from the front, right front compartment 1R1, right middle compartment 1R2, and right rear compartment 1R3, and the three left-hand compartments of the six compartments will be appropriately referred to as, from the front, left front compartment 1L1, left middle compartment 1L2, and left rear compartment 1L3.

[0024] In the vehicle body underbody structure 1 of this embodiment, the structure described below is adopted for a target section, which is at least one section among a plurality of sections divided by high-strength members (20, 30, 40, 50). Although not particularly limited, in the illustrated example, the target sections are the right middle section 1R2 and the left middle section 1L2. The right middle section 1R2 and the left middle section 1L2 have the same structure except that they are symmetrical to each other. Below, the structure of the right middle section 1R2 and its surroundings will mainly be described.

[0025] (Details of the underbody structure) Next, the detailed structure of the vehicle body lower structure 1 will be described with a focus on the right intermediate section 1R2 and its surrounding structure. Fig. 4 is a cross-sectional view taken along line AA in Fig. 2, Fig. 5 is a cross-sectional view taken along line BB in Fig. 2, Fig. 6 is a partial perspective view of a cut model taken along line CC in Fig. 2, and Fig. 7 is a perspective view for explaining the shape of the floor panel 10 in the main part of Fig. 3. Figs. 2 to 7 each show a portion including the right intermediate section 1R2. In Fig. 7, the reinforcing member 60 described later has been removed, and the outer shape of the reinforcing member 60 is shown by a two-dot chain line.

[0026] 4 to 6, in the vehicle body underbody structure 1, as described above, no member having a relatively large cross section corresponding to the floor side member of a conventional vehicle body underbody structure is joined to the underside of the floor panel 10. And, a power supply unit B including a battery pack is disposed below the floor panel 10. In other words, the floor panel 10 is a member disposed above the power supply unit B including the battery pack in the vehicle body underbody.

[0027] 4, the lower portion of the side sill 30 (side sill bulge 31) along the outer edge of the floor panel 10 in the vehicle width direction protrudes downward from the lower surface of the floor panel 10. The space (allowable placement space) for placing the power supply unit B under the floor panel 10 is expanded outward in the vehicle width direction to the inner side surface of the inner wall 31a of the side sill bulge 31 of the side sill 30 in the vehicle width direction. In other words, since the lower surface of the floor panel 10 in the vehicle body lower structure 1 does not have a conventional floor side member provided, the allowable placement space for the power supply unit B is expanded outward in the vehicle width direction to the outer edge of the floor panel 10 in the vehicle width direction. In the illustrated example, a small gap is provided between the outer side surface B1 of the power supply unit B in the vehicle width direction and the inner side surface of the inner wall 31a in the vehicle width direction, but the unit width of the power supply unit B in the vehicle width direction can be expanded (widened) to the separation distance between the right side sill 30 (inner wall 31a) and the left side sill 30 (inner wall 31a).

[0028] 2 to 7, the floor panel 10 has a raised portion 13 that rises above the vehicle, and a flat portion 14 that surrounds the periphery of the raised portion 13.

[0029] The raised portion 13 occupies most of the area of ​​the right middle section 1R2 of the floor panel 10 and is a portion that bulges upward of the vehicle as a whole. The raised portion 13 has a generally rectangular shape when viewed in the vertical direction of the vehicle (for example, in a plan view viewed from above the vehicle). The raised portion 13 has an edge bead 13a and a lower bulge 13b.

[0030] The edge bead 13a constitutes the outer edge of the raised portion 13 and protrudes above the vehicle. The edge bead 13a extends in a generally rectangular ring shape. The edge bead 13a extends in a ring shape with a cross-sectional shape that bulges above the vehicle. The top of the edge bead 13a is formed flat, and the edge bead 13a has a generally trapezoidal outer shape.

[0031] The lower bulge 13b constitutes an inner portion of the edge bead 13a of the raised portion 13 and bulges downward of the vehicle. In other words, the inner portion of the raised portion 13 is recessed downward of the vehicle, thereby forming the edge bead 13a on the outer edge of the raised portion 13. The outer edge of the lower bulge 13b is surrounded by the edge bead 13a.

[0032] The flat portion 14 is a portion surrounding the periphery of the raised portion 13, and has flat surfaces without any unevenness extending in the vehicle front-rear direction and the vehicle width direction without any raised portion in the vehicle vertical direction. In the floor panel 10, the height position of the lower surface 14a of the flat portion 14 in the vehicle vertical direction is set to the same level over the entire floor panel 10. The opening edge portion 11 of the floor panel 10 is formed continuously with the flat portion 14 on the floor tunnel 20 side, and the vertical flange 12 of the floor panel 10 is formed continuously with the flat portion 14 on the side sill 30 side (outside in the vehicle width direction). Here, the flat portion 14 (more specifically, the lower surface 14a of the flat portion 14) is used as the reference for the height position in the vehicle vertical direction. In this case, the floor tunnel 20 (tunnel bulging portion 21), the first floor cross member 40, and the second floor cross member 50 all protrude (bulge) upward from the flat portion 14 of the floor panel 10.

[0033] In the vehicle body understructure 1, the lower bulging portion 13b bulges downward, but the lower bulging portion 13b is formed in the raised portion 13 that is raised upward. As a result, the height position of the lower end 13b1 of the lower bulging portion 13b is offset upward by the raised height of the raised portion 13 (the bead height of the edge bead 13a). Therefore, the vehicle body understructure 1 has a structure that can reduce or eliminate the downward protrusion amount of the lower bulging portion 13b relative to the lower surface 14a of the flat portion 14 compared to the conventional structure. If the lower bulging portion 13b were formed in the flat portion 14 that is not raised upward (i.e., in the case of the sunken portion of the conventional vehicle body understructure), the lower bulging portion 13b would necessarily protrude downward from the lower surface 14a of the flat portion 14 by the bulging amount of the lower bulging portion 13b.

[0034] Generally, the underside of the vehicle body must have a certain minimum ground clearance, which is the distance from the running surface to the bottom surface of the underside of the vehicle body. When the power supply unit is disposed below the floor panel, it is possible to offset the height position of the floor panel toward the interior of the vehicle from the viewpoint of ensuring the minimum ground clearance. However, this narrows the space inside the vehicle interior, which is undesirable from the viewpoint of ensuring the space inside the vehicle interior. When considering the securing of space inside the vehicle interior and the minimum ground clearance, it may be necessary to dispose the power supply unit as close as possible to the underside of the floor panel.

[0035] Regarding the arrangement of the power supply unit B, (1) in the vehicle body understructure 1 of this embodiment, the lower surface 14a of the floor panel 10 (flat portion 14) is not provided with a conventional floor side member, so that the power supply unit B can be brought closer to the floor panel 10 by the height of the floor side member. (2) Furthermore, in the vehicle body understructure 1 of this embodiment, the lower bulge portion 13b is formed on the raised portion 13 that is raised upward, and the amount of downward protrusion of the lower bulge portion 13b relative to the lower surface 14a of the flat portion 14 can be reduced or eliminated, so that the power supply unit B can be brought even closer to the lower surface 14a of the floor panel 10 (flat portion 14). (3) In this way, the vehicle body understructure 1 has a structure that allows the space for arranging the power supply unit B below the floor panel 10 to be expanded in the vehicle width direction and toward the floor panel 10.

[0036] Returning to Fig. 1, in this embodiment, the raised portion 13 is provided in each of a first region A1 and a second region A2 that are adjacent to each other with a gap in the vehicle width direction in the floor panel 10. In this embodiment, the first region A1 and the second region A2 are set in at least one section (i.e., the target section) of the multiple sections (1R1, 1R2, 1R3, 1L1, 1L2, 1L3) of the floor panel 10 that are divided by the high-strength members (20, 30, 40, 50).

[0037] In the illustrated example, the first area A1 and the second area A2 are set in the right middle section 1R2 and the left middle section 1L2, respectively. That is, in the right middle section 1R2 of the floor panel 10, two raised portions 13 are provided adjacent to each other with a space therebetween in the vehicle width direction, and in the left middle section 1L2 of the floor panel 10, two raised portions 13 are also provided adjacent to each other with a space therebetween in the vehicle width direction. In the right middle section 1R2, the first area A1 and the second area A2 occupy most of the area of ​​the right middle section 1R2, and in the left middle section 1L2, the first area A1 and the second area A2 occupy most of the area of ​​the left middle section 1L2. Therefore, the two raised portions 13 occupy most of the area of ​​the right middle section 1R2, and similarly, the two raised portions 13 occupy most of the area of ​​the left middle section 1L2. Although not particularly limited, in the illustrated example, the first region A1 is a region located on the outer side in the vehicle width direction relative to the second region A2.

[0038] Specifically, referring to FIG. 7, the area of ​​the first region A1 on the outer side in the vehicle width direction is not the same as the area of ​​the second region A2 on the inner side in the vehicle width direction. The area of ​​the first region A1 is larger than the area of ​​the second region A2. The dividing point between the first region A1 and the second region A2 is shifted toward the inner side in the vehicle width direction with respect to the center of the right middle section 1R2 in the vehicle width direction, and the right middle section 1R2 is intentionally divided unequal in the vehicle width direction by the first region A1 and the second region A2. That is, the first raised portion 131 which is the raised portion 13 provided in the first region A1 is formed with an area larger than the second raised portion 132 which is the raised portion 13 provided in the second region A2. The first raised portion 131 and the second raised portion 132 are spaced apart from each other in the vehicle width direction, and the flat portion 14 surrounds the periphery of the first raised portion 131 and also surrounds the periphery of the second raised portion 132. Furthermore, the position in the vehicle width direction of the reinforcing member 60, which will be described later, is set at a position that divides the area of ​​the first raised portion 131 and the area of ​​the second raised portion 132 unequally in one section.

[0039] In this embodiment, in each of the raised portions (131, 132), the lower bulging portion 13b bulges downward (is concave) with a curvature (1 / r). In the illustrated example, as shown in Figs. 4 and 6, in each of the raised portions (131, 132), the lower bulging portion 13b bulges downward with a substantially constant curvature (1 / r), in other words, with a substantially constant radius of curvature r. Therefore, the upper and lower surfaces of the lower bulging portion 13b are formed as curved surfaces with a radius of curvature r, and the lower bulging portion 13b has a curved surface (in other words, a spherical surface or a bulging surface) with a radius of curvature r. However, the radius of curvature r of the curved surface of the lower bulging portion 13b is not limited to being substantially constant, and may change continuously, for example, like a downwardly convex paraboloid of revolution, or may change intermittently.

[0040] 4, the amount of bulging of the lower bulging portion 13b of the first raised portion 131 (total height of the lower bulging portion 13b) is the same or approximately the same as the amount of bulging of the lower bulging portion 13b of the second raised portion 132 (total height of the lower bulging portion 13b). Therefore, the radius of curvature r1 of the curved surface of the lower bulging portion 13b of the first raised portion 131, which has a larger area than the second raised portion 132, is set to be larger than the radius of curvature r2 of the curved surface of the lower bulging portion 13b of the second raised portion 132, and the curved surface of the first raised portion 131 is curved more gently than the curved surface of the second raised portion 132.

[0041] In this embodiment, in each raised portion (131, 132), the lower end 13b1 of the lower bulging portion 13b is located above the lower surface 14a of the flat portion 14 in the vertical direction of the vehicle. In other words, the lower bulging portion 13b bulges downward, but the lower end 13b1 of the lower bulging portion 13b does not protrude downward beyond the lower surface 14a of the flat portion 14 in the vertical direction of the vehicle. The amount of downward protrusion of the lower bulging portion 13b with respect to the lower surface 14a of the flat portion 14 is zero.

[0042] The power supply unit B is disposed close to the lower surface 14a of the flat portion 14 of the floor panel 10. Specifically, a first gap G1 is provided between the upper surface B2 of the power supply unit B and the lower surface 14a of the flat portion 14 of the floor panel 10. A second gap G2 is provided between the upper surface B2 of the power supply unit B and the lower end 13b1 of the lower bulging portion 13b of the floor panel 10. Since the lower end 13b1 of the lower bulging portion 13b is located above the lower surface 14a of the flat portion 14, the second gap G2 is wider vertically than the first gap G1 (G2>G1). Although not shown, harnesses and piping are laid in the gap between the upper surface B2 of the power supply unit B and the floor panel 10.

[0043] In this embodiment, the vehicle body understructure 1 includes a reinforcing member 60 that extends in the vehicle front-rear direction on the upper surface side of the floor panel 10 and is joined to the first floor cross member 40 and the raised portion 13. The reinforcing member 60 is made of a metal plate material, and in the illustrated example, is provided in the right middle section 1R2 and the left middle section 1L2. Note that the reinforcing member 60 also has the function of an existing support bracket for attaching, to the vehicle body, appropriate outfitting parts that may be provided between the floor panel 10 and a seat (not shown), for example.

[0044] 4 and 6, the reinforcing member 60 has a hat-shaped cross-sectional shape that opens downwardly of the vehicle when viewed in the front-rear direction of the vehicle. Specifically, the reinforcing member 60 has a main body portion 61, a front joining flange 62, and a rear joining flange 63.

[0045] The main body 61 has a reinforcing bulge 61a, a first leg 61b, and a second leg 61c. The reinforcing bulge 61a bulges upward in a generally trapezoidal shape when viewed in the vehicle front-rear direction and extends in the vehicle front-rear direction, constituting a main part of the reinforcing member 60. The first leg 61b protrudes outward in the vehicle width direction from a lower edge of a side wall on the outer side in the vehicle width direction of the reinforcing bulge 61a. The second leg 61c protrudes inward in the vehicle width direction from a lower edge of a side wall on the inner side in the vehicle width direction of the reinforcing bulge 61a.

[0046] The front joint flange 62 bends from the front end of the main body 61 to extend forward along the flat portion 14. The rear joint flange 63 bends from the rear end of the main body 61 to extend rearward along the flat portion 14. Specifically, the front joint flange 62 has a front gradually changing portion 62a that gradually changes from a hat-shaped cross-sectional shape to a thin plate shape and a front flat portion 62b that follows the flat portion 14 when viewed in the vehicle longitudinal direction. The rear joint flange 63 has a rear gradually changing portion 63a that gradually changes from a hat-shaped cross-sectional shape to a thin plate shape and a rear flat portion 63b that follows the flat portion 14 when viewed in the vehicle longitudinal direction.

[0047] As shown in FIG. 5, the reinforcing member 60 also has a wide hat-shaped cross section that opens downwardly of the vehicle when viewed in the vehicle width direction.

[0048] 4 and 7, in this embodiment, the edge bead 13a of each raised portion (131, 132) has front and rear bead portions 13a1 that overlap the reinforcing member 60 when viewed in the vehicle vertical direction and extend in the vehicle front-rear direction. The front and rear bead portions 13a1 of the first raised portion 131 and the front and rear bead portions 13a1 of the second raised portion 132 extend in the front-rear direction adjacent to each other with a gap therebetween, and the reinforcing member 60 is disposed so as to follow the two adjacent front and rear bead portions 13a1. The reinforcing member 60 is disposed so as to cover the flat portion 14 between the first raised portion 131 and the second raised portion 132, which is the dividing portion (boundary portion) between the first raised portion 131 and the second raised portion 132.

[0049] In the illustrated example, in each raised portion (131, 132), the edge bead 13a extends in a generally rectangular ring shape and has front and rear bead portions 13a1 overlapping the reinforcing member 60, an opposing bead portion 13a2, a front bead portion 13a3, and a rear bead portion 13a4. The opposing bead portion 13a2 faces the front and rear bead portion 13a1 overlapping the reinforcing member 60 at a distance in the vehicle width direction and extends in the vehicle front-rear direction. The front bead portion 13a3 extends in the vehicle width direction and connects the front end of the front and rear bead portions 13a1 and the front end of the opposing bead portion 13a2. The rear bead portion 13a4 extends generally in the vehicle width direction and connects the rear end of the front and rear bead portions 13a1 and the rear end of the opposing bead portion 13a2.

[0050] The edge bead 13a of each raised portion (131, 132) has corners (front corners and rear corners) that curve (bend) in the vehicle width direction from the ends of the front and rear bead portions 13a1 that run along the reinforcing member 60. The edge bead 13a runs along the reinforcing member 60 at the front and rear bead portions 13a1 and curves in the vehicle width direction at the corners.

[0051] The edge bead 13a is surrounded by the floor tunnel 20, the side sill 30, the first floor cross member 40, and the second floor cross member 50. The front and rear bead portions 13a1 and the opposing bead portion 13a2 each extend parallel to the floor tunnel 20, the side sill 30, and the reinforcing member 60, and the front bead portion 13a3 and the rear bead portion 13a4 each extend parallel to the first floor cross member 40 and the second floor cross member 50. The bead width (bead thickness) of the edge bead 13a is set appropriately according to the rigidity, etc. required of the floor panel 10 in the right intermediate section 1R2, and can be set to different widths as appropriate for each element (13a1, 13a2, 13a3, 13a4).

[0052] Referring to FIG. 7, the outer edge of each raised portion (131, 132) is adjacent to a drainage portion 15 having a drainage hole 15a. The drainage hole 15a is opened at the center of the drainage portion 15. A part of the outer edge of the drainage portion 15 is continuous with the edge bead 13a of the corresponding raised portion (131 or 132). In the illustrated example, the drainage portion 15 is adjacent to the outer part of the rear bead portion 13a4 in the vehicle width direction in the first raised portion 131, and is adjacent to the inner part of the rear bead portion 13a4 in the vehicle width direction in the second raised portion 132. The bead height of the part of the rear bead portion 13a4 that is continuous with the drainage portion 15 is lower than the bead height of the other parts. Even if liquid accumulates in the lower bulge portion 13b, the liquid accumulated in the lower bulge portion 13b is easily led to the drainage portion 15.

[0053] In addition, the lower bulge 13b of each of the raised portions (131, 132) is formed with a plurality of protrusions 16 protruding upward from the vehicle. In the illustrated example, each of the protrusions 16 has a truncated cone shape when viewed from above. Although not particularly limited, the first raised portion 131 is provided with seven protrusions 16, and the second raised portion 132 is provided with five protrusions 16. In each of the raised portions (131, 132), some of the plurality of protrusions 16 are adjacent to the edge bead 13a and are continuous with the edge bead 13a. In the first raised portion 131, two protrusions 16 are adjacent to the front and rear bead portions 13a1, and one protrusion 16 is adjacent to the rear bead portion 13a4. In the second raised portion 132, two protrusions 16 are adjacent to the front and rear bead portions 13a1.

[0054] Referring to Figures 2 to 4, in this embodiment, the reinforcing member 60 straddles the front and rear bead portions 13a1 of the first raised portion 131 and the front and rear bead portions 13a1 of the second raised portion 132 in the vehicle width direction, and is joined to the lower bulge portion 13b of the first raised portion 131 and the lower bulge portion 13b of the second raised portion 132.

[0055] In the illustrated example, in the reinforcing member 60, the first leg 61b is joined by spot welding or the like to two protruding portions 16 adjacent to the front and rear bead portions 13a1 of the first raised portion 131, and the second leg 61c is joined by spot welding or the like to each of the two protruding portions 16 adjacent to the front and rear bead portions 13a1 of the second raised portion 132. In other words, the reinforcing member 60 is disposed so as to sandwich the two adjacent front and rear bead portions 13a1 from the outer sides in the vehicle width direction and is joined to the floor panel 10, connecting the first raised portion 131 and the second raised portion 132 that are spaced apart in the vehicle width direction.

[0056] In this embodiment, the front flat portion 62b of the front joining flange 62, which is one end of the reinforcing member 60 in the vehicle fore-and-aft direction, is joined to the first floor cross member 40, and the rear flat portion 63b of the rear joining flange 63, which is the other end of the reinforcing member 60 in the vehicle fore-and-aft direction, is joined to the second floor cross member 50.

[0057] In the illustrated example, in the reinforcing member 60, the front joint flange 62 (front flat portion 62b) is joined to the first joint bulge portion 43a formed at the vehicle width direction middle of the first rear flange 43 of the first floor cross member 40, and the rear joint flange 63 (rear flat portion 63b) is joined to the second joint bulge portion 52a formed at the vehicle width direction middle of the second front flange 52 of the second floor cross member 50. In detail, the joint bulge portions (43a, 52a) have a width approximately equal to the vehicle width direction width of the joint flanges (62, 63), and bulge slightly upward of the vehicle. The front flat portion 62b is sandwiched between the first joint bulge portion 43a and the floor panel 10, and the front flat portion 62b, the first joint bulge portion 43a, and the floor panel 10 are joined in a three-ply configuration by spot welding or the like. Similarly, the rear flat portion 63b is sandwiched between the second joint bulge portion 52a and the floor panel 10, and the rear flat portion 63b, the second joint bulge portion 52a, and the floor panel 10 are joined in three layers by spot welding or the like.

[0058] 4 and 5, in this embodiment, the overall height h1 of the intermediate portion in the vehicle vertical direction, which is the overall height (height) of the intermediate portion in the vehicle longitudinal direction of the reinforcing member 60 (in other words, the overall thickness of the intermediate portion), is higher (longer) than the overall height h2 of the end portion in the vehicle vertical direction, which is the overall height (height) of the end portion in the vehicle longitudinal direction of the reinforcing member 60 (in other words, the thickness of the end portion). Specifically, the main body portion 61, which is the intermediate portion in the vehicle longitudinal direction of the reinforcing member 60, has a hat-shaped cross-sectional shape when viewed in the vehicle longitudinal direction, and the overall height h1 of the intermediate portion is the height of the bulge of the main body portion 61 in the vehicle vertical direction. On the other hand, the front joint flange 62 and the rear joint flange 63, which are the end portions in the vehicle longitudinal direction of the reinforcing member 60, gradually change from a hat-shaped cross-sectional shape to a thin plate shape when viewed in the vehicle longitudinal direction, and the overall height h2 of the end portion decreases from the overall height h1 of the intermediate portion to the plate thickness of the front flat portion 62b and the rear flat portion 63b.

[0059] According to the vehicle body underbody structure 1 of this embodiment, the floor panel 10 arranged above the power supply unit B in the lower part of the vehicle body has a raised portion 13 that rises above the vehicle and a flat portion 14 that surrounds the raised portion 13, and the raised portion 13 has an edge bead 13a that forms the outer edge of the raised portion 13 and protrudes above the vehicle, and a lower bulge portion 13b that forms an inner portion of the edge bead 13a in the raised portion 13 and bulges below the vehicle. In this configuration, (1) since no conventional floor side member is provided on the underside 14a of the floor panel 10 (flat portion 14), the power supply unit B can be brought closer to the floor panel 10 by the height of the floor side member, and (2) furthermore, since the lower bulge 13b is formed on the upwardly protruding raised portion 13, the amount of downward protrusion of the lower bulge 13b relative to the underside 14a of the flat portion 14 can be reduced or eliminated, so that the power supply unit B can be brought even closer to the underside 14a of the floor panel 10 (flat portion 14). (3) In this way, the vehicle body underbody structure 1 has a structure that allows the space for arranging the power supply unit B below the floor panel 10 to be expanded in the vehicle width direction and toward the floor panel 10.

[0060] According to the vehicle body underbody structure 1, the lower bulge 13b is formed in the raised portion 13 that is raised upward, so that the amount of downward bulge (bulge height) of the lower bulge 13b can be made larger (higher) than in the past, while suppressing the amount of downward protrusion from the lower surface 14a of the flat portion 14. As a result, the rigidity of the floor panel 10 is increased by the lower bulge 13b. Furthermore, the rigidity of the floor panel 10 is increased not only by the lower bulge 13b but also by the edge bead 13a. As a result, the vibration of the floor panel 10 in the vertical direction can be suppressed.

[0061] As described above, the vehicle body underbody structure 1 of this embodiment is a structure that can increase the rigidity of the floor panel 10 while expanding the space for placing the power supply unit B below the floor panel 10 in the vehicle width direction and toward the floor panel 10.

[0062] In this embodiment, the vehicle body lower structure 1 further includes a first floor cross member 40 that is joined to the floor panel 10 and protrudes upward from the flat portion 14 and extends in the vehicle width direction, and a reinforcing member 60 that extends in the vehicle front-rear direction on the upper surface side of the floor panel 10 and is joined to the first floor cross member 40 and the raised portion 13, and the edge bead 13a has front-rear bead portions 13a1 that overlap with the reinforcing member 60 when viewed in the vehicle up-down direction and extend in the vehicle front-rear direction. The rigidity of the portions of the floor panel 10 whose rigidity has been increased by the front-rear bead portions 13a1 can be further increased by the reinforcing member 60 and the first floor cross member 40.

[0063] In this embodiment, the raised portions 13 are provided in the first region A1 and the second region A2 adjacent to each other with a gap therebetween in the vehicle width direction in the floor panel 10, and the rigidity of the dividing portion between the first region A1 and the second region A2 (i.e., the portion between the first raised portion 131 and the second raised portion 132) may decrease. In contrast, in this embodiment, the reinforcing member 60 straddles in the vehicle width direction the front and rear bead portions 13a1 of the first raised portion 131 provided in the first region A1 and the front and rear bead portions 13a1 of the second raised portion 132 provided in the second region A2, and is joined to the lower bulge portion 13b of the first raised portion 131 and the lower bulge portion 13b of the second raised portion 132. With this configuration, the reinforcing member 60 is disposed to sandwich the two adjacent front and rear bead portions 13a1 from the outer sides in the vehicle width direction and is joined to the floor panel 10, connecting the first raised portion 131 and the second raised portion 132 that are spaced apart in the vehicle width direction. As a result, the reinforcing member 60 can effectively increase the rigidity (surface rigidity) of the divided portion between the first region A1 and the second region A2.

[0064] In this embodiment, in the vehicle body lower structure 1, the reinforcing member 60 is joined to the first floor cross member 40 and the second floor cross member 50 adjacent to each other on the upper surface side of the floor panel 10, so that the rigidity of the reinforcing member 60 is increased by the two high rigidity members on the upper surface side of the floor panel 10, and further, this reinforcing member 60 is used to reinforce the floor panel 10. As a result, the rigidity (surface rigidity) of the floor panel 10 can be more effectively increased.

[0065] In this embodiment, the intermediate portion overall height h1, which is the overall height in the vehicle vertical direction of the intermediate portion in the vehicle fore-aft direction of the reinforcing member 60, is higher than the end portion overall height h2, which is the overall height in the vehicle vertical direction of the end portion in the vehicle fore-aft direction of the reinforcing member 60. As a result, the rigidity of the abdominal portion, which has a large amplitude in the vertical vibration of the floor panel 10 (specifically, in the illustrated example, the right intermediate section 1R2 and the left intermediate section 1L2), can be effectively increased by the intermediate portion (in the illustrated example, the main body portion 61) of the reinforcing member 60, which has the intermediate portion overall height h1.

[0066] In this embodiment, the lower bulge portion 13b bulges downward with a curvature (1 / r), so that the lower and upper surfaces of the lower bulge portion 13b are formed as curved surfaces. This efficiently improves the rigidity of the floor panel 10. In addition, in the raised portion 13, the edge bead 13a protruding upward surrounds the periphery of the lower bulge portion 13b and has a predetermined bead width. Therefore, the area of ​​the lower bulge portion 13b in the raised portion 13 is reduced by the bead width of the edge bead 13a compared to the area of ​​the lower bulge portion 13b when the lower bulge portion 13b bulges downward from the flat portion 14. As a result, for example, in a case where the downward bulge amount (protruding height) of the lower bulge portion 13b is set to a predetermined amount and is restricted, the curvature (1 / r) of the lower bulge portion 13b increases by the area reduction of the lower bulge portion 13b, so that the rigidity of the floor panel 10 can be efficiently increased by the lower bulge portion 13b. That is, the power supply unit B needs to be close to the floor panel 10 to ensure battery capacity and minimum ground clearance, but if it is close to the floor panel 10, the floor side members cannot be placed on the underside of the floor panel 10. Therefore, the edge bead 13a provides upward height, while the raised portion 13 is formed with a curved surface that bulges downward with a curvature (1 / r). In particular, by arranging multiple curved surfaces with curvature, the curvature (1 / r) can be made large (in other words, the radii of curvature r1 and r2 can be made small).

[0067] In this embodiment, the first region A1 and the second region A2 in which the raised portion 13 is provided are set in at least one section (in the illustrated example, the right middle section 1R2 and the left middle section 1L2) of a plurality of sections (1R1, 1R2, 1R3, 1L1, 1L2, 1L3) in the floor panel 10, which are partitioned by the floor tunnel 20, the side sill 30, the first floor cross member 40, and the second floor cross member 50. With this configuration, the raised portion 13 is provided in, for example, a section in the floor panel 10 where improved rigidity may be particularly required, and the rigidity of the floor panel 10 can be efficiently improved.

[0068] In this embodiment, the lower end 13b1 of the lower bulge 13b of the raised portion 13 is located above the lower surface 14a of the flat portion 14 of the floor panel 10 in the vehicle vertical direction. With this configuration, a gap (space) for laying a harness or the like can be easily and reliably secured between the upper surface B2 of the power supply unit B and the floor panel 10.

[0069] In the illustrated example, the edge bead 13a of each raised portion (131, 132) has corners (front and rear corners) that curve (bend) in the vehicle width direction from the ends of the front and rear bead portions 13a1 along the reinforcing member 60, and has a bead shape that extends in the vehicle width direction from the corners. As a result, the edge bead 13a utilizes the rigidity of the reinforcing member 60 to more effectively increase the rigidity of the floor panel 10. In addition, the reinforcing member 60 also has the function of an existing support bracket for attaching appropriate fitting parts to the vehicle body, so there is no need to provide a separate part for reinforcing the floor panel 10, and the floor panel 10 can be reinforced from the inside of the vehicle compartment without increasing the number of parts.

[0070] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment, and further modifications and changes are possible based on the technical concept of the present invention.

[0071] For example, in this embodiment, the position of the reinforcing member 60 in the vehicle width direction is set at a position that unequally divides the area of ​​the first raised portion 131 and the area of ​​the second raised portion 132 in one section, but is not limited to this. In order to maximize the improvement in rigidity (vibration amplitude suppression) of the floor panel 10, the position of the reinforcing member 60 in the vehicle width direction can be set at a position that equally divides the area of ​​the first raised portion 131 and the area of ​​the second raised portion 132. Note that the target frequency characteristics for the vibration of the floor panel 10 differ from vehicle to vehicle and may also differ from one section position of the floor panel 10 to another. Therefore, maximizing the rigidity of the floor panel 10 is not necessarily advantageous.

[0072] For example, in this embodiment, the raised portion 13 is provided in the right middle section 1R2 and the left middle section 1L2, but is not limited thereto. The positions and number of sections in which the raised portion 13 is provided may be determined according to the rigidity required for the floor panel 10, and the raised portion 13 may be provided in at least one of the multiple sections. Also, one raised portion 13 may be provided in one section, or three or more raised portions 13 may be provided.

[0073] Furthermore, the lower end 13b1 of the lower bulge 13b of the raised portion 13 may be located slightly below the lower surface 14a of the flat portion 14 of the floor panel 10 in the vertical direction of the vehicle. Even in this case, since the entire raised portion 13 is raised above the vehicle, the vehicle body underbody structure 1 can reduce the amount of downward projection of the lower bulge 13b from the lower surface 14a of the flat portion 14 compared to the conventional case, and the power supply unit B can be disposed near the floor panel 10 while a gap for laying a harness or the like can be easily secured between the floor panel 10 and the power supply unit B. [Explanation of symbols]

[0074] 1...Vehicle underbody structure 10…Floor panel 13...Protuberance 13a…Edge bead 13a1…Front and rear bead sections 13b…lower bulge 13b1…lower end 131...1st raised part 132…Second raised part 14...Flat area 14a…Bottom surface 20…Floor tunnel 30…Side sill 40…First floor cross member 50…Second floor cross member 60…Reinforcing member 62b...Front flat portion (one end) 63b... Rear flat portion (other end) 1R1, 1R2, 1R3, 1L1, 1L2, 1L3...multiple areas h1...Middle part height (total height) h2…End height (total height) A1…First area A2…Second area B…Power supply unit

Claims

1. A vehicle underbody structure including a floor panel disposed above a power supply unit in a vehicle underbody, The floor panel has a raised portion that is raised above the vehicle and a flat portion that surrounds the raised portion, a lower bulge portion that forms an inner portion of the raised portion relative to the edge bead and bulges downwardly from the vehicle, the lower bulge portion forming an outer edge portion of the raised portion and protruding upwardly from the vehicle, the lower bulge portion forming an inner portion of the raised portion relative to the edge bead and bulging downwardly from the vehicle,

2. a first floor cross member joined to the floor panel, protruding upward relative to the flat portion and extending in a vehicle width direction; a reinforcing member extending in the vehicle front-rear direction on an upper surface side of the floor panel and joined to the first floor cross member and the raised portion; Further comprising: The vehicle body underbody structure according to claim 1 , wherein the edge bead has front and rear bead portions that overlap the reinforcing member when viewed in a vehicle up-down direction and extend in a vehicle front-rear direction.

3. The raised portion is provided in each of a first region and a second region adjacent to each other in a vehicle width direction on the floor panel, 3. The vehicle body understructure according to claim 2, wherein the reinforcing member spans in the vehicle width direction between the front and rear bead portions of a first raised portion, which is the raised portion provided in the first region, and the front and rear bead portions of a second raised portion, which is the raised portion provided in the second region, and is joined to the lower bulge portion of the first raised portion and the lower bulge portion of the second raised portion.

4. a second floor cross member joined to the floor panel at a position spaced apart from the first floor cross member in the vehicle front-rear direction and protruding upward from the flat portion and extending in the vehicle width direction, The vehicle body understructure as described in claim 3, wherein one end of the reinforcing member in the vehicle fore-and-aft direction is joined to the first floor cross member, and the other end of the reinforcing member in the vehicle fore-and-aft direction is joined to the second floor cross member.

5. 2. The vehicle underbody structure according to claim 1, wherein an overall height in the vehicle vertical direction of a middle portion in the vehicle fore-aft direction of the reinforcing member is greater than an overall height in the vehicle vertical direction of an end portion in the vehicle fore-aft direction of the reinforcing member.

6. The vehicle underbody structure according to claim 1 , wherein the lower bulging portion bulges downward with a curvature.

7. a floor tunnel provided in a vehicle width direction intermediate portion of the floor panel, bulging upward from the flat portion and extending in a vehicle front-rear direction; A side sill provided at an outer edge of the floor panel in a vehicle width direction and extending in a vehicle front-rear direction; Further comprising: the floor panel is divided into a plurality of sections by the floor tunnel, the side sill, the first floor cross member, and the second floor cross member, The vehicle underbody structure according to claim 4 , wherein the first area and the second area are set in at least one of the plurality of compartments.

8. 8. The vehicle underbody structure according to claim 1, wherein a lower end of the lower bulge portion is positioned above a lower surface of the flat portion in the vehicle up-down direction.

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