Vehicle body floor structure

Abstract

To provide a vehicle body floor part structure advantageous for utilizing a floor tunnel part as a reinforcing structure cooperating with a floor cross member while securing a battery mounting space.SOLUTION: The vehicle body floor portion structure includes a floor tunnel that terminates at a rear end portion located in a middle of a vehicle cabin, and a floor cross member that is connected to a vehicle body skeleton member at an end portion in a vehicle width direction, A rear end portion of the floor tunnel is constituted by a tunnel rear end member, the tunnel rear end member includes a tunnel rear wall portion extending between a front edge portion joined to an upper wall and side walls of the floor tunnel and side edge portions and a rear edge portion joined to the floor panel, and the floor cross member is provided with a cutout portion extending from a front wall of the floor cross member to a front portion of the upper wall so as to intersect with the tunnel rear end member and extend in the vehicle width direction, and an upper bracket covering an upper side of the cutout portion and joined to the upper wall of the floor tunnel.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Traditionally, a floor tunnel running lengthwise has been formed in the center of the vehicle floor. This floor tunnel was a basic structure required to accommodate the propeller shaft in the FR vehicles that were once mainstream, and has continued to be used as a reinforcing structure for the vehicle floor that also serves as a space to accommodate the exhaust pipe, even after FF vehicles became mainstream.

[0003] However, in recent years, improvements in vehicle body design technology have diminished the significance of reinforcing structures, while securing mounting space for batteries with increased capacity due to the electrification of powertrains in electric vehicles, hybrid vehicles, etc. For example, Patent Document 1 discloses a structure in which the floor tunnel terminates in front of the seats, leaving the floor under the seats flat and available as mounting space for a battery pack. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7197254 Summary of the Invention [Problem to be solved by the invention]

[0005] By partially eliminating the floor tunnel and making the passenger compartment floor flat, the floor cross member that was previously divided into left and right halves by the floor tunnel can be replaced with a floor cross member that extends across the entire width of the passenger compartment floor.By connecting both ends of this member to the side sills, which are the skeletal structure of the underside of the vehicle body, it is possible to ensure the rigidity of the vehicle floor while also ensuring space for installing a battery.

[0006] However, in Patent Document 1, the remaining floor tunnel portion is separated from the floor cross member, and the floor tunnel portion cannot be utilized as a reinforcing structure in conjunction with the floor cross member, which remains an issue.

[0007] The present invention was made in consideration of these circumstances, and its purpose is to provide a vehicle floor structure that is advantageous for utilizing the floor tunnel portion as a reinforcing structure in conjunction with the floor cross member while ensuring space for installing a battery. [Means for solving the problem]

[0008] In order to solve the above problems, the vehicle body floor structure according to the present invention comprises: a floor panel that defines the floor surface of the vehicle compartment; a floor tunnel that protrudes upward from a center portion of the floor panel in a vehicle width direction, extends rearward in a vehicle length direction from a front portion of the passenger compartment, and terminates at a rear end portion located in a middle of the passenger compartment; a floor cross member extending in the vehicle width direction on the floor panel, including a front wall, a rear wall, an upper wall extending between an upper end of the front wall and an upper end of the rear wall, and flange portions formed at the lower end of the front wall and the lower end of the rear wall, the floor cross member having a hat-shaped cross section and connected to a vehicle body frame member at an end in the vehicle width direction; The rear end of the floor tunnel is formed by a tunnel rear end member, The tunnel rear end member includes a front edge portion joined to the upper wall and side wall of the floor tunnel, a side edge portion and a rear edge portion joined to the floor panel, and a tunnel rear wall portion extending between the front edge portion, the side edge portion and the rear edge portion, The floor cross member has a cutout portion extending from the front wall of the floor cross member to the front portion of the upper wall, so that the cutout portion intersects with the tunnel rear end member and extends in the vehicle width direction, and an upper bracket is provided that covers the upper part of the cutout portion and is joined to the upper wall of the floor tunnel. [Effects of the Invention]

[0009] As described above, the vehicle body floor structure according to the present invention is advantageous in that the floor cross-member extending across the entire vehicle width of the passenger compartment floor is positioned to intersect, i.e., overlap, with the rear end of the floor tunnel, thereby forming a highly rigid floor structure in which the floor tunnel and floor cross-member are linked together. In addition, compared to a configuration in which the floor tunnel and floor cross-member do not intersect, this configuration has the advantage that the rear end of the floor tunnel can be extended rearward, thereby improving the utilization efficiency of the interior space, or the floor cross-member can be positioned further forward, thereby enabling the flat floor space behind the floor cross-member to be extended further forward. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a plan view showing a vehicle body floor structure according to an embodiment of the present invention; [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] FIG. 2 is an enlarged perspective view of a main portion showing the vicinity of the rear end of the front floor tunnel. [Figure 4] FIG. 10 is an enlarged perspective view of a main portion showing the vicinity of the rear end of the front floor tunnel with the upper bracket removed. [Figure 5] FIG. 10 is an enlarged perspective view of a main portion showing the vicinity of the rear end of the front floor tunnel with the front floor cross member removed. [Figure 6] FIG. 2 is an enlarged perspective view of a main portion near the upper bracket as seen from the rear. [Figure 7] 3 is an enlarged cross-sectional view of a main part of FIG. 2 showing the vicinity of the rear end of the front floor tunnel. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0012] In the following description, unless otherwise specified, front and rear refer to front and rear in the vehicle length direction (FR), left and right refer to left and right in the vehicle width direction (W), and up and down refer to up and down in the vehicle height direction (H).

[0013] Furthermore, in the following description, unless otherwise specified, it is assumed that each panel and each member that constitutes the vehicle body floor section is press-formed using metal plate, particularly steel plate, and that the "joining" of each panel and each member is welded, particularly spot welding (resistance spot welding, laser spot welding), but this does not exclude configurations using other materials, other molding methods, or other joining methods.

[0014] (Basic structure of the vehicle floor) 1, left and right floor panels 10, 10 that define the underside of the vehicle body are joined at both sides to side sills 12, 12. The side sills 12, 12 are body frame members that extend in the vehicle length direction FR on the underside of the vehicle body, and typically have a closed cross-sectional structure extending in the longitudinal direction, in which a side sill outer that has a hat-shaped cross section protruding outward in the vehicle width direction and that forms the outer surface of the lower part of the vehicle body, and a side sill inner that also has a hat-shaped cross section protruding toward the center in the vehicle width direction are joined directly or via a reinforcing material.

[0015] Floor side members 11, 11 extending in the vehicle length direction FR are joined to the undersides of the floor panels 10, 10 adjacent to the center of the side sills 12, 12 in the vehicle width direction. The floor side members 11, 11 have an inverted hat-shaped cross section and are joined to the undersides of the floor panels 10, 10 at both flange portions, defining a closed cross section extending in the longitudinal direction within the floor side members 11, 11. The floor side members 11, 11 are disposed obliquely in a plan view so that the distance between them increases toward the rear of the vehicle.

[0016] Two front and rear floor cross members 21, 22 extending in the vehicle width direction W between the left and right side sills 12, 12 are joined to the upper surfaces of the floor panels 10, 10 at a distance in the vehicle length direction FR. The front and rear floor cross members 21, 22 each have a hat-shaped cross section, and a closed cross section extending in the vehicle width direction W is defined inside each.

[0017] The left and right floor panels 10, 10 have a floor front portion 101 in front of the front floor cross member 21, a floor middle portion 102 between the front floor cross member 21 and the rear floor cross member 22, and both side portions 103 of the floor rear portion behind the rear floor cross member 22, which form a generally flat floor low surface.

[0018] In contrast, a high surface 104 is formed in the center of the rear part of the floor in the vehicle width direction W. The front side of the high surface 104 is continuous with the floor intermediate part 102 via an inclined surface 105, and both sides of the high surface 104 in the vehicle width direction W are continuous with the side parts 103 via inclined surfaces 106. Therefore, the rear part of the floor has a three-dimensional shape including the side parts 103, which are low surfaces on both sides, and the central high surface 104, but the left and right floor panels 10, 10 are each continuous with a roughly constant width from the floor front part 101 to the floor rear part, as shown in FIG. 1, and each is press-formed from a single blank.

[0019] A front floor tunnel 13 is provided in the center of the left and right floor panels 10, 10 in the vehicle width direction W. The front floor tunnel 13 protrudes upward and extends rearward in the vehicle length direction from the front of the passenger compartment, terminating near a front floor cross member 21 located in the middle of the passenger compartment. The front floor tunnel 13 has a hat-shaped cross section that bulges out in the vehicle height direction H relative to the floor panels 10, 10, and a front end 135 is inclined upward toward the front in the vehicle length direction along a dash panel (not shown).

[0020] A substantially flat floor center panel 15 is disposed behind the front floor tunnel 13 in the center of the left and right floor panels 10, 10 in the vehicle width direction W, between the front floor cross member 21 and the rear floor cross member 22. With this configuration, a flat portion extending across the entire width in the vehicle width direction W is formed in the floor intermediate portion 102 between the front floor cross member 21 and the rear floor cross member 22. This flat portion defines a storage space 150 (FIG. 2) for a battery 7 (HEV battery for driving a motor generator of a hybrid vehicle) below the left and right seats 6 (front seats).

[0021] Furthermore, a rear floor tunnel 16 extending rearward in the vehicle length direction from the rear floor cross member 22 is provided behind the floor center panel 15 at the center of the left and right floor panels 10, 10 in the vehicle width direction W. As mentioned above, since a high surface 104 is formed at the center of the rear part of the floor in the vehicle width direction, the rear floor tunnel 16 has a smaller relative height to the floor panel 10 (104) than the front floor tunnel 13.

[0022] With the above-described configuration, a rear underfloor space 160 is defined below the rear of the floor by the central rear floor tunnel 16 and the high surfaces 104 on both sides of it. As shown in Figures 1 and 2, this rear underfloor space 160 serves as a storage space for the muffler 82 (main chamber) provided midway through the exhaust pipe 8.

[0023] The front floor cross member 21 is provided with seat brackets 25, 26 for attaching front portions 65 of slide rails 66 of the left and right seats 6 (front seats), and the rear floor cross member 22 is provided with seat brackets 27, 28 for attaching rear portions 67 of the slide rails 66. Of these, the front seat brackets 25, 25 on the center side of the left and right seats 6 in the vehicle width direction are provided integrally with the upper bracket 23, and the rear seat brackets 27, 27 on the center side of the left and right seats 6 in the vehicle width direction are provided integrally with the upper bracket 24. The upper bracket 23 will be described later.

[0024] (Tunnel rear end component that forms the rear end of the front floor tunnel) As shown in Figure 5, in which the upper bracket 23 and front floor cross member 21 are omitted, the rear end of the front floor tunnel 13 that intersects with the front floor cross member 21 is composed of a tunnel rear end member 14 that is separate from the main part of the front floor tunnel 13.

[0025] The tunnel rear end member 14 is joined to the rear end of the front floor tunnel 13 at a front edge portion (141, 142, 143) having a cross-sectional shape corresponding to the rear end of the front floor tunnel 13. That is, the upper portion 143 of the front edge portion is joined to the rear end of the upper wall 133 of the front floor tunnel 13, and the side portions 141, 142 of the front edge portion are joined to the side walls 131, 132 of the front floor tunnel 13.

[0026] The side walls 131, 132 of the front floor tunnel 13 have an upper portion 132 that is gently inclined relative to the lower portion 131, and the side portions 141, 142 of the front edge of the tunnel rear end member 14 are also formed with an upper portion 142 that is gently inclined relative to the lower portion 141. In addition, flange portions 113 provided on the edge of the floor panel 10 are joined to the lower end portions of the lower portion 131 of the side wall of the front floor tunnel 13 and the lower portion 141 of the tunnel rear end member 14.

[0027] The tunnel rear end member 14 has a tunnel rear wall 146 that defines an inclined surface that extends to the floor surface (low surface) behind the front edge portions (141, 142, 143). The central portion of the tunnel rear wall 146 is an inclined surface that descends rearward from the upper portion 143, but both side portions 147 of the tunnel rear wall 146 are inclined obliquely to the left and right in accordance with the inclination of the side walls 131, 132 of the front floor tunnel 13 and the front edge side portions 141, 142.

[0028] Furthermore, the tunnel rear end member 14 has flat portions (144, 145) including a rear edge portion 145 extending rearward from the lower portion of the tunnel rear wall portion 146 along the floor surface and side edge portions 144 extending laterally. The rear edge portion 145 is overlapped and joined onto a front edge portion 155 of the floor center panel 15 adjacent to the rear side of the tunnel rear end member 14. In addition, the side edge portions 144 extending and overlapping the undersides of the left and right floor panels 10 are joined to the floor panels 10.

[0029] The flange portion 113 of the floor panel 10 terminates at both side portions 147 of the tunnel rear wall portion 146, and the edge portion 114 on the center side of the vehicle width direction of the floor panel 10 extending rearward from this is a flat edge portion that follows the flat portions (144, 145) of the tunnel rear wall portion 146 and the upper surface of the floor center panel 15.

[0030] 5, the side edge portions 144 of the tunnel rear end member 14 coincide with the side edge portions 134 of the front floor tunnel 13 and the side edge portions 154 of the floor center panel 15, and extend toward the underside of the floor panel 10. These side edge portions 134, 144, 154 are formed with a series of inverted hat-shaped cross-sectional portions 138-158 (FIG. 1) that protrude downward and extend in the vehicle length direction, and by joining these side edge portions 134, 144, 154 to the underside of the floor panel 10, a series of closed cross-sections (138-158; FIG. 1) that extend in the vehicle direction are formed from the left and right side edge portions 134 of the front floor tunnel 13 to the left and right side edge portions 154 of the floor center panel 15.

[0031] Furthermore, although not shown in the figures, in a preferred form, an upwardly protruding reinforcing bead is formed on the edge of the floor panel 10 located above the inverted hat-shaped cross-sectional portions 138-158 of the side edge portions 134, 144, and 154, and this reinforcing bead expands the above-mentioned closed cross-section upward.

[0032] (Intersection structure between the rear end of the front floor tunnel and the front floor cross member) As shown in Figure 4, the front floor cross member 21 has a cutout portion 210 that extends from the front wall 211 of the front floor cross member 21 to the front portion of the upper wall 213, so as to intersect above the tunnel rear end member 14 and extend in the vehicle width direction W.

[0033] The cutout 210 is formed in an area obtained by expanding the cross section where the basic shape of the front floor cross member 21 (the shape when the cutout 210 is not present) intersects with the tunnel rear end member 14 rearward in the vehicle length direction and laterally in the vehicle width direction. In other words, the cutout 210 is sized so that the front floor cross member 21 does not come into contact with the tunnel rear end member 14, and a generally uniform gap is defined between the edge of the cutout 210 and the tunnel rear end member 14.

[0034] Furthermore, the cutout portion 210 is formed partially relative to the width of the upper wall 213 in the vehicle length direction. By leaving the upper wall 213 partially intact, a bent portion remains between the rear wall 212 and the upper wall 213 of the front floor cross member 21 on the rear side thereof, and the cross-sectional shape of the front floor cross member 21 is maintained even in the section where the cutout portion 210 is formed.

[0035] In addition, on both sides of the vehicle width direction of the portion where the cutout portion 210 of the front floor cross member 21 is formed, partition walls (not shown) are provided which are joined to the inner surfaces of the front wall 211, rear wall 212, and upper wall 213 so as to divide the cross section of the front floor cross member 21.

[0036] Except at the intersection with the front floor tunnel 13, the front floor cross member 21 is joined to the floor panel 10 at a front flange portion 214 extending forward from the lower end of the front wall 211 and a rear flange portion 215 extending rearward from the lower end of the rear wall 212.However, as shown in Figure 7, at the front edge portion 155 of the floor center panel 15 to which the rear edge portion 145 of the tunnel rear end member 14 is joined, they are joined to the rear flange portion 215 in a three-layer configuration.

[0037] Preferably, as shown in Figure 7, the rear edge portion 145 of the tunnel rear end member 14 extends rearward in the vehicle length direction beyond the rear flange portion 215 of the front floor cross member 21, and is joined to the floor center panel 15 at this extending portion (145).

[0038] (The joint structure between the rear end of the front floor tunnel and the front floor cross member) As described above, in the section of the cutout portion 210, a gap is formed between the front floor cross member 21 and the tunnel rear end member 14, and the front floor cross member 21 and the tunnel rear end member 14 are not directly joined. In addition, in the section of the cutout portion 210, the cross section is reduced compared to the section without the cutout portion 210, and a relative decrease in strength cannot be denied.

[0039] Therefore, in order to reinforce the front floor cross member 21 in the section of the cutout portion 210 and at the same time form a joint with the rear end portion of the front floor tunnel 13, an upper bracket 23 is provided that covers the upper part of the cutout portion 210 and is joined to the upper wall 133 of the front floor tunnel 13.

[0040] As shown in Figures 3 and 6, the upper bracket 23 has a basic box-like or trapezoidal shape extending in the vehicle width direction with substantially the same width as the upper wall 213 of the front floor cross member 21 so as to expand the cross section of the front floor cross member 21 upward in the section of the cutout portion 210.

[0041] Specifically, the upper bracket 23 has a front wall portion 231 that has a joint 230 with the front wall 211 of the front floor cross member 21 on both sides of the cutout portion 210 in the vehicle width direction and rises so as to extend the front wall 211 upward, a rear wall portion 234 (Figure 6) that has a joint 238 with the rear wall 212 of the front floor cross member 21 at its lower part and rises so as to extend the rear wall 212 upward, an upper wall portion 237 that extends between the upper edge of the front wall portion 231 and the upper edge of the rear wall portion 234, and side wall portions 235 that extend downward from the side edges of the upper wall portion 237 on both sides in the vehicle width direction and are joined to the upper wall 213 of the front floor cross member 21 with flange portions 236 that extend laterally from each lower end, and is formed into a box shape by joining pieces folded back from the side edges of the front wall portion 231 and the side edges of the rear wall portion 234 to the back sides of both sides of the side wall portion 235.

[0042] Furthermore, in the middle of the front wall portion 231 of the upper bracket 23 in the vehicle width direction, flange portions 232, 233 are formed which extend forward in the vehicle length direction from the edge portion which is formed into an approximately trapezoidal tunnel shape to fit the rear end portion of the front floor tunnel 13 and the side to upper shape of the front edge portion (142, 143) of the tunnel rear end member 14, and these flange portions 232, 233 are joined to the side wall 132 and upper wall 133 of the front floor tunnel 13 to which the front edge portion (142, 143) of the tunnel rear end member 14 is joined.

[0043] That is, the upper bracket 23 is joined in three layers to the side wall 132 of the front floor tunnel 13 and the side portion 142 of the front edge portion of the tunnel rear end member 14 at the flange portion 232 extending forward in the vehicle length direction from the side edge portion of the tunnel-shaped edge portion, and is joined in three layers to the upper wall 133 of the front floor tunnel 13 and the upper portion 142 of the front edge portion of the tunnel rear end member 14 at the flange portion 233 extending forward in the vehicle length direction from the upper edge portion of the tunnel-shaped edge portion.

[0044] As described above, the front floor cross member 21 is rigidly connected on three sides to the front floor tunnel 13 and the tunnel rear end member 14 via the upper bracket 23, which is advantageous in ensuring the rigidity of the vehicle floor portion.

[0045] Moreover, the upper bracket 23 is provided with seat mounting structures 25, such as seating surfaces and bolt holes (weld nuts), for mounting the front portions 65 of the slide rails 66 of the left and right seats 6 (front seats) on both sides of the upper wall portion 237 in the vehicle width direction, and thus functions as a seat bracket (25). Therefore, as described above, by integrating the seat mounting structures 25 into the upper bracket 23, which reinforces the joint between the front floor tunnel 13 and the front floor cross member 21, there is also the advantage that the mounting rigidity of the left and right seats 6 can be ensured while suppressing an increase in the number of parts.

[0046] In particular, in a preferred embodiment, the flange portion 236 of the upper bracket 23 includes a joint point with the upper flange of a partition wall (not shown) provided within the cross section of the front floor cross member 21 and the upper wall 213 of the front floor cross member 21, and the joint portion 230 of the adjacent front wall portion 231 of the upper bracket 23 includes a joint point with the front flange of the partition wall and the front wall 211 of the front floor cross member 21, and the joint portion 238 of the rear wall portion 234 includes a joint point with the rear flange of the partition wall and the rear wall 212 of the front floor cross member 21, and since the seat bracket (25) is joined to the floor panel 10 or the tunnel rear end member 14 near these joint points, the load applied to the seat bracket (25) is transmitted and dispersed to the surrounding area.

[0047] In a preferred embodiment, the upper bracket 23 is pre-joined to the front floor cross member 21 to prepare it as a front floor cross member assembly, and when joined to the side sills 12, 12 and floor panels 10, 10 as the front floor cross member assembly, it is joined to the front floor tunnel 13 (tunnel rear end member 14).

[0048] Furthermore, among the components that make up the vehicle floor, the thickness of the panels that make up the floor surface, such as the floor panel 10, front floor tunnel 13, tunnel rear end member 14, floor center panel 15, and rear floor tunnel 16, is greater than the thickness of the body frame components, such as the floor side member 11, side sill 12, front floor cross member 21, and rear floor cross member 22, and brackets (mounting components, reinforcing components) such as the upper bracket 23, rear bracket 24, and seat brackets 26, 28.

[0049] Furthermore, in the above, the thickness of the tunnel rear end member 14 and / or the floor center panel 15 may be greater than the thickness of the other panels and may be equal to or intermediate with the thickness of the bracket group. Therefore, the tunnel rear end member 14 may be configured as a tunnel rear end reinforcing member or a tunnel rear end bracket, and / or the floor center panel 15 may be configured as a floor centering force.

[0050] (Main components and effects) As described above, the vehicle floor structure of the present invention is advantageous in constructing a highly rigid floor structure that connects the front floor tunnel 13 and the front floor cross member 21, as the rear end of the front floor tunnel 13 is constructed from a separate tunnel rear end member 14, while a cutout portion 210 is formed extending from the front wall 211 of the front floor cross member 21 to the front portion of the upper wall 213, and an upper bracket 23 is provided that covers the upper part of the cutout portion 210 and is joined to the upper wall 133 of the front floor tunnel 13.

[0051] In other words, the rear end (tunnel rear end member 14) of the front floor tunnel 13 and the front floor cross member 21 are arranged to intersect (overlap) each other, so that the rear end (front edge portions 141, 142, 143 of the tunnel rear end member 14), which maintains the cross-sectional shape of the front floor tunnel 13, and the front floor cross member 21 are arranged close to each other, and therefore they can be firmly and rigidly connected by the upper bracket 23.

[0052] Furthermore, the cutout portion 210 creates a gap between the front floor cross member 21 and the tunnel rear end member 14 (tunnel rear wall portion 146), which has the advantage of making it easier to control the dimensions of the tunnel rear end member 14 and the front floor cross member 21.

[0053] In addition, the rear end of the front floor tunnel 13 (tunnel rear end member 14) is extended rearward to within the cross section of the front floor cross member 21, and compared to a configuration in which the front floor tunnel 13 and the front floor cross member 21 do not intersect, the space under the front tunnel 130 is expanded rearward, thereby improving the utilization efficiency of the interior space of the vehicle.

[0054] For example, as shown in Figure 2, when an exhaust gas purification device 81 (catalytic converter) or a sub-muffler is placed in the space under the front tunnel 130, there is an advantage that the piping of the exhaust pipe 83 extending rearward from the exhaust gas purification device 81 becomes easier.

[0055] Alternatively, compared to a configuration in which the front floor tunnel 13 and the front floor cross member 21 do not intersect, the front floor cross member 21 can be positioned further forward, and the flat floor space 150 behind the front floor cross member 21 can be extended further forward.

[0056] For example, as shown in Figure 2, when a battery 7 (HEV battery) is mounted between the front floor cross member 21 and the rear floor cross member 22, the storage space for the battery 7 is expanded forward, which has the advantage of allowing a larger battery to be mounted. In this case, the amount of movement of the front floor cross member 21 in the fore-and-aft direction is less than the fore-and-aft width of the members, but the floor space 150 is expanded forward across the entire width of the vehicle, resulting in a high space expansion efficiency.

[0057] In a preferred embodiment of the present invention, the upper wall portion 237 of the upper bracket 23 is located higher than the upper wall 133 of the front floor tunnel 13, which is located higher than the upper wall 213 of the front floor cross member 21, and the upper bracket 23 extends in the vehicle width direction across the upper side of the tunnel rear end member 14. In other words, in a configuration in which the upper wall 213 of the front floor cross member 21 is located lower than the upper wall 133 of the front floor tunnel 13, the upper bracket 23 reinforces the cross section of the front floor cross member 21 in a state in which it is expanded upward, and the front floor tunnel 13 (tunnel rear end member 14) is joined in a manner that accommodates the cross section of the front floor tunnel 13 (tunnel rear end member 14), which is advantageous in improving the rigidity of the joint between the front floor cross member 21 and the front floor tunnel 13 (tunnel rear end member 14).

[0058] In a preferred embodiment of the present invention, the rear edge portion 145 of the tunnel rear end member 14 extends rearward in the vehicle length direction beyond the rear flange portion 215 extending from the lower end of the rear wall 212 of the front floor cross member 21, as shown in Figure 7, and is joined to the front edge portion 155 of the floor center panel 15 at this extended portion (145).

[0059] Since this extension portion (145) is substantially flat, it does not affect the use of the floor space 150 defined above the floor center panel 15. In addition, its configuration of extending rearward beyond the rear flange portion 215 of the front floor cross member 21 makes it possible to join in two rows: at the two-piece joint point with the floor center panel 15 when joining the left and right floor panels 10, 10, the front floor tunnel 13, the floor center panel 15, and the rear floor tunnel 16 to form the floor surface before assembling the front floor cross member 21 (and the rear floor cross member 22), and then at the three-piece joint point with the rear flange portion 215 when assembling the front floor cross member 21, which is advantageous in ensuring the joining strength of the floor center panel 15.

[0060] In the above embodiment, the tunnel rear wall portion 146 of the tunnel rear end member 14 extends linearly and inclined from the upper portion 143 of the leading edge portion to the trailing edge portion 145, as shown in Figure 7, but it can also be formed to extend non-linearly with a change in the inclination angle or a stepped shape.

[0061] In the above description, the shape expressed as flat may be substantially flat, and may include a case where there are some irregularities.

[0062] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made within the scope of the present invention based on the technical concept of the present invention. [Explanation of symbols]

[0063] 10 Floor Panel 12 Side sill (body frame member) 13 Front floor tunnel 14 Tunnel rear end member 15 Floor center panel 16 Rear floor tunnel 21 Front floor cross member 22 Rear floor cross member 23 Upper bracket 130 Space under the front tunnel 131,132 side wall 133 Upper Wall 141, 142 Side (leading edge) 143 Upper part (leading edge) 144 Side edge 145 Trailing edge 146 Tunnel rear wall 210 Notch 211 Front wall 212 Back wall 213 Upper Wall

Claims

1. A vehicle body floor structure, a floor panel that defines the floor surface of the vehicle compartment; a floor tunnel that protrudes upward from a center portion of the floor panel in a vehicle width direction, extends rearward in a vehicle length direction from a front portion of the passenger compartment, and terminates at a rear end portion located in a middle of the passenger compartment; a floor cross member extending in the vehicle width direction on the floor panel, including a front wall, a rear wall, an upper wall extending between an upper end of the front wall and an upper end of the rear wall, and flange portions formed at the lower end of the front wall and the lower end of the rear wall, the floor cross member having a hat-shaped cross section and connected to a vehicle body frame member at an end in the vehicle width direction; The rear end of the floor tunnel is formed by a tunnel rear end member, The tunnel rear end member includes a front edge portion joined to the upper wall and side wall of the floor tunnel, a side edge portion and a rear edge portion joined to the floor panel, and a tunnel rear wall portion extending between the front edge portion, the side edge portion and the rear edge portion, A vehicle floor structure in which the floor cross member has a cutout portion formed therein extending from the front wall of the floor cross member to the front portion of the upper wall so as to intersect with the tunnel rear end member and extend in the vehicle width direction, and an upper bracket is provided which covers the upper part of the cutout portion and is joined to the upper wall of the floor tunnel.

2. The upper bracket comprises a front wall portion having joints with the front wall of the floor cross member on both sides of the cutout portion in the vehicle width direction and extending between the joints on both sides, a rear wall portion joined to the rear wall of the floor cross member, an upper wall portion extending between the upper edge of the front wall portion and the upper edge of the rear wall portion on both sides of the cutout portion in the vehicle width direction, and both side wall portions extending downward from the side edges on both sides of the vehicle width direction of the upper wall portion and joined to the upper wall of the floor cross member by flange portions extending laterally from each lower end, 2. A vehicle floor structure as described in claim 1, wherein the joint between the upper wall and the tunnel rear end member of the floor tunnel is provided on a flange portion extending forward in the vehicle length direction from the front wall portion.

3. The vehicle body floor structure described in claim 2, wherein the upper bracket further has a joint with the side wall to which the tunnel rear end member of the floor tunnel is joined, and the joint is provided on a flange portion extending forward in the vehicle length direction from the front wall portion.

4. The vehicle floor structure of claim 3, wherein the upper wall portion of the upper bracket is located higher than the upper wall of the floor tunnel, which is located higher than the upper wall of the floor cross member, and the upper bracket extends in the vehicle width direction across the upper side of the tunnel rear end member.

5. The vehicle floor structure described in claim 3, wherein the upper bracket is pre-joined to the floor cross member to form a floor cross member assembly, and the upper bracket and the floor cross member are joined to the tunnel rear end member as the floor cross member assembly.

6. 6. The vehicle body floor structure according to claim 1, wherein a seat mounting structure is provided on the upper wall of the upper bracket, and the upper bracket functions as a seat bracket.

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