Vehicle body floor structure

Abstract

To provide a vehicle body floor part structure advantageous for utilizing a residual 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 comprises a front floor tunnel which terminates at a rear end portion positioned at a middle of a cabin, a rear floor tunnel which extends rearward from a front edge joint portion positioned in back of the front floor tunnel, and front and rear floor cross members which are connected to vehicle-body frame members at end portions, in a vehicle width direction, of the front floor tunnel, wherein the rear floor cross member extends in the vehicle width direction above a front end portion of the rear floor tunnel.SELECTED DRAWING: Figure 1

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 floor tunnel portion and the floor cross member are separated, and the floor tunnel portion cannot be utilized as a reinforcing structure linked to 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 remaining 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 front 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 rear floor tunnel extending rearward in the vehicle length direction from a leading edge joint portion located rearward in the vehicle length direction with respect to the rear end portion of the front floor tunnel; front and rear floor cross members extending in the vehicle width direction on the floor panel, each including a front wall, a rear wall, an upper wall extending between the upper end of the front wall and the 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, and having a hat-shaped cross section, and connected to a vehicle body frame member at an end in the vehicle width direction, and the rear floor cross member is disposed rearward in the vehicle length direction with a gap therebetween relative to the front floor cross member; The rear floor cross member extends in the vehicle width direction, intersecting above the front end of the rear floor tunnel. [Effects of the Invention]

[0009] As described above, the vehicle body floor structure according to the present invention is configured such that the front floor cross-member extending across the entire vehicle width of the passenger compartment floor intersects with the rear end of the front floor tunnel, and the rear floor cross-member extending across the entire vehicle width of the passenger compartment floor behind it intersects with the front end of the rear floor tunnel, i.e., they overlap, which is advantageous in forming a highly rigid floor structure in which the front and rear floor cross-members, the rear end of the front floor tunnel, and the front end of the rear floor tunnel are linked together. In addition, an accommodation space surrounded by highly rigid members across the entire vehicle width is secured on the floor between the front floor cross-member and the rear floor cross-member, which is suitable for use as a battery installation space. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a vehicle body floor structure according to an embodiment of the present invention; [Figure 2] 1 is a plan view showing a vehicle body floor structure according to an embodiment of the present invention; [Figure 3] 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] FIG. 10 is a perspective view showing the rear end portion of the front floor tunnel with the seat bracket removed. [Figure 5] FIG. 10 is a perspective view showing the vicinity of the rear end of the front floor tunnel with the upper bracket removed. [Figure 6] FIG. 10 is a perspective view showing the vicinity of the rear end of the front floor tunnel with the front floor cross member removed. [Figure 7] This is an oblique view of the vicinity of the front end of the rear floor tunnel as seen from the rear. [Figure 8] This is an oblique view of the vicinity of the front end of the rear floor tunnel with the rear bracket removed, as seen from the rear. [Figure 9] 1 is a perspective view of the vicinity of the front end of the rear floor tunnel with the rear floor cross member removed, seen from the rear. FIG. [Figure 10] FIG. 4 is an enlarged cross-sectional view of a main part of FIG. 3. 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 and 2, 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 side flange portions, defining a closed cross section extending in the longitudinal direction within the floor side members 11, 11. As shown in Figure 2, the floor side members 11, 11 are arranged diagonally 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 as shown in Figures 1 and 2.

[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 both side parts 103 via inclined surfaces 106. Therefore, the rear part of the floor has a three-dimensional shape including both 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. 2, 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 for a battery 7 (an 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, and a rear bracket 24 is joined between the upper wall and rear wall of the rear floor cross member 22 and the upper surface of the rear floor tunnel 16 located behind it. As mentioned above, a high surface 104 is formed in the center of the rear part of the floor in the vehicle width direction, so 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 2 and 3, this rear underfloor space 160 serves as a storage space for the muffler 82 (main chamber) provided midway through the exhaust pipe 8.

[0023] In the vehicle floor structure shown in the figure, both ends of the rear floor cross member 22 are joined to the slide rail front end accommodating portion 128 of the left and right sliding doors, which is formed in a curved shape from the left and right side sills 12, 12 toward the center in the vehicle width direction, so that the length in the vehicle width direction W is shorter than that of the front floor cross member 21.

[0024] The front floor cross member 21 is provided with a pair of seat brackets 25, 26 for attaching front portions 65 of slide rails 66 of the left and right seats 6 (front seats). The rear floor cross member 22 is provided with a seat bracket 27 on the center side in the vehicle width direction for attaching rear portions 67 of the slide rail 66. The seat bracket 28 on the outer side in the vehicle width direction is disposed on a panel (not shown) that covers the upper portions of the slide rail front end accommodating portions 128 (of the left and right sliding doors), as shown schematically in FIG.

[0025] (Tunnel rear end component that forms the rear end of the front floor tunnel) As shown in Figures 3 to 7, particularly Figure 6 in which the front floor cross member 21 is 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.

[0026] The tunnel rear end member 14 is joined to the rear end of the front floor tunnel 13 at its front edge portion (141, 142, 143) which has the same cross-sectional shape as 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 1 and 2, 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 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) extending 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.

[0032] 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.

[0033] (Intersection structure between the front floor tunnel and the front floor cross member) As shown in Figure 5, the front floor cross member 21 has a cutout portion 210 formed in the front wall 211 of the front floor cross member 21, which is larger than the cross section intersecting with the tunnel rear wall portion 146 of the tunnel rear end member 14, so that the front floor cross member 21 intersects above the tunnel rear end member 14 and extends in the vehicle width direction W.

[0034] The cutout portion 210 is formed partially relative to the height of the front wall 211 so that a front wall remainder 211a extending in the vehicle width direction remains above the cutout portion 210. By leaving the front wall remainder 211a, the rigidity of the floor cross member can be ensured more than in a shape without the front wall remainder 211a.

[0035] Furthermore, on both sides of the portion of the front floor cross member 21 where the cutout portion 210 is formed, partition walls 216, 216 joined to the inner surfaces of the front wall 211, rear wall 212, and upper wall 213 are provided so as to separate the cross section of the front floor cross member 21. These partition walls 216, 216 are provided corresponding to the mounting portions of the seat brackets 25, 25 shown in Figure 1, and also function as reinforcing structures for the mounting portions of the seat brackets 25, 25.

[0036] In addition, other than at the intersection with the rear end of the front floor tunnel, the front floor cross member 21 is joined to the floor panel 10 at the front flange portion 214 extending forward from the lower end of the front wall 211 and the rear flange portion 215 extending rearward from the lower end of the rear wall 212, but 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 triple layer.

[0037] Preferably, as shown in Figure 10, 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 upper wall of the front floor tunnel and the front floor cross member) At the cutout portion 210, a gap is formed between the front floor cross member 21 and the tunnel rear end member 14 (tunnel rear wall portion 146), and the front floor cross member 21 and the tunnel rear end member 14 are not directly joined. Therefore, an upper bracket 23 is provided at the top of the front floor cross member 21 and the front floor tunnel 13 (tunnel rear end member 14) to connect them.

[0039] As shown in Figures 4 and 10, the upper bracket 23 has an upper wall portion 231 joined to the upper wall 213 of the front floor cross member 21, and a front wall portion 232 extending downward from the front edge of the upper wall portion 231 and joined to the front wall 211 of the front floor cross member 21 on both sides of the cutout portion 210, and has an L-shaped cross-sectional shape, and is joined at a front edge portion 233 extending forward from the middle of the front wall portion 232 to the upper wall 133 of the front floor tunnel 13 to which the tunnel rear end member 14 is joined.

[0040] Furthermore, by providing side edge portions 234 on both sides of the front edge portion 233 of the upper bracket 23 in the vehicle width direction that are joined to the side walls 132 of the front floor tunnel 13, the front floor cross member 21 is joined via the upper bracket 23 to the upper wall 133 of the front floor tunnel 13 to which the tunnel rear end member 14 is joined and the side walls 132 on both sides thereof.

[0041] In this way, 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 body floor portion.

[0042] In addition, the upper bracket 23, together with the seat brackets 25, 26, is pre-joined to the upper wall 213 and front wall 211 of the front floor cross member 21 to prepare 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 preferably joined to the front floor tunnel 13 (tunnel rear end member 14).

[0043] (Intersection structure between rear floor tunnel and rear floor cross member) Next, the structure of the intersection between the rear floor tunnel 16 and the rear floor cross member 22 will be described with reference to FIGS.

[0044] As shown in Figure 9, the rear floor portion of the floor panel 10 has both side edges 103 of the rear floor that form a low floor surface that continues from the floor intermediate portion 102, while a high surface 104 is formed in the center in the vehicle width direction. As already mentioned, the front side of the high surface 104 continues to the floor intermediate portion 102 via an inclined surface 105. More specifically, the inclined surface 105 includes a lower inclined surface 108 hidden under the rear floor cross member 22, a flat surface 107 that continues to the rear side, and an upper inclined surface (105), and is formed in a stepped shape with the flat surface 107 halfway between the lower inclined surface 108 and the upper inclined surface. The flat surface 107 is the joining surface for the rear flange portion 227 of the rear floor cross member 22.

[0045] The rear floor tunnel 16 corresponds to the shape of the rear of the floor as described above and includes a front edge portion 165 joined to the rear edge portion 156 of the floor center panel 15, a front end inclined portion 161 corresponding to the lower part of the inclined surface continuing to its rear side, a flat joint portion 162 corresponding to the flat surface continuing to its rear side, an inclined portion 163 corresponding to the upper part of the inclined surface continuing to its rear side, a flat upper wall 164 continuing to its rear side, and side walls continuing on both sides of the portion extending from the front end inclined portion 161 to the upper wall 164.The rear floor tunnel 16 is formed in a stepped shape with the flat joint portion 162 at a height intermediate between the front edge portion 165 and the upper wall 164, and the side edges 114 to 116 of the floor panel 10 are joined in a superimposed state onto the side edges 166 extending laterally from the lower parts of the side walls on both sides.

[0046] 3 and 10, a rear floor cross member lower 29 is disposed below the rear floor cross member 22, sandwiching the rear floor tunnel 16. This rear floor cross member lower 29 has a lower wall 291 and a rear wall 292 extending upward from its rear end, has a substantially L-shaped cross section, extends in the vehicle width direction, and is joined to the lower surface of the rear floor tunnel 16 by a front flange 295 extending forward from the front end of the lower wall 291 and a rear flange 296 extending rearward from the upper end of the rear wall 292, thereby forming a closed cross section.

[0047] The rear edge portion 156 of the floor center panel 15 is joined in two pieces to the front edge portion 165 of the rear floor tunnel 16. At the front edge base portion 165e of the rear floor tunnel 16 adjacent to the rear of the panel, the front flange portion 225 of the rear floor cross member 22 that overlaps it and the front flange 295 of the rear floor cross member lower 29 that overlaps them are joined in three pieces.

[0048] On the other hand, the rear flange 296 of the rear floor cross-member lower 29 is joined in a three-piece configuration to the rear flange portion 226 of the rear floor cross-member 22 at the flat joint portion 162 of the rear floor tunnel 16.

[0049] The front edge base 165e of the rear floor tunnel 16 protrudes upward from the front edge 165 via a step portion having a dimension equivalent to the plate thickness of the floor center panel 15, and the rear edge 156 of the floor center panel 15 leaves edge portions (156) located on both sides of the front edge base 165e of the rear floor tunnel 16 in the vehicle width direction, and a recessed edge portion 156c is formed in the center of the vehicle width direction to escape the front edge base 165e. With the above configuration, the front flange portion 225 of the rear floor cross member 22 extends approximately flat along the floor low surface.

[0050] In contrast, the rear flange portions 226, 227 of the rear floor cross member 22 have a floor surface formed in a stepped manner, including low surfaces (103) on both sides in the vehicle width direction, a flat surface 107 at the center that is raised by the inclination of the lower inclined surface 108, and a flat joint portion 162 of the rear floor tunnel 16 that protrudes from the center.Therefore, as shown in Figure 8, the central rear flange portion 226 that is joined to the flat joint portion 162 of the rear floor tunnel 16 is formed at a higher position than the low surfaces (103), compared to the rear flange portions 227 that extend on both sides in the vehicle width direction and are joined to the floor panel 10 (103, 107).

[0051] Therefore, the rear floor cross member 22 is arranged so that the front end inclined portion 161 of the rear floor tunnel 16 is accommodated below the rear floor cross member 22 due to the gap formed below the rear flange portion 226, in other words, the rear floor cross member 22 is positioned above the front end inclined portion 161 of the rear floor tunnel 16 in an intersecting manner and the two are joined to each other.

[0052] The rear floor cross-member lower 29 is provided in the rear part of the floor excluding both side portions 103, in the middle part in the vehicle width direction W of the rear floor tunnel 16 and its flat surfaces 107 and lower inclined surfaces 108 on both sides thereof, and both ends of the rear floor cross-member lower 29 in the vehicle width direction are closed by brackets made of separate members. Therefore, the rear floor cross-member lower 29 extends in the vehicle width direction at least within the width range of the floor center panel 15.

[0053] 1 and 2, the upper wall 223 of the rear floor cross member 22 is at approximately the same height from one end to the other in the vehicle width direction, but as shown in Fig. 8, the cross-sectional shape may change near the seat bracket 27, with the upper wall 224 in the center in the vehicle width direction being at a higher position than the upper walls 223 on both sides in the vehicle width direction. In this configuration, the change in cross section of the rear wall 222 due to the rise of the rear flange portion 226 is kept small.

[0054] (Joint structure between rear floor tunnel and rear floor cross member) At the intersection between the rear floor tunnel 16 having the basic structure described above and the rear floor cross member 22, a rear bracket 24 is provided that is joined to connect the upper wall 224 of the rear floor cross member 22 and the upper wall 164 of the rear floor tunnel 16 in order to improve the connection strength and rigidity of this area.

[0055] As shown in FIG. 7, the rear bracket 24 has an upper wall portion 243 including an upper wall joint portion 244 joined to the upper wall 224 of the rear floor cross member 22, and side wall portions 242 extending downward from both side edges thereof, forming a basic shape with a hat-shaped cross section extending in the vehicle length direction, and is joined to the upper wall 164 and the inclined portion 163 of the rear floor tunnel 16 at flange portions 247 extending laterally from the lower edges of the side wall portions 242. Furthermore, the rear bracket 24 is joined in three layers to the flat joint portion 162 of the rear floor tunnel 16 at the lowest portion 247b of the flange portion 247, which is formed in a stepped shape according to the shape of the rear floor tunnel 16, with the rear flange portion 226 of the rear floor cross member 22 sandwiched between them.

[0056] In addition, a recess 246 extending in the vehicle length direction is formed on the rear side of the center of the vehicle width direction of the upper wall portion 243 of the rear bracket 24, and the bottom of this recess 246 is also joined to the upper wall 164 of the rear floor tunnel 16.

[0057] An opening 240 is formed in the upper wall portion 243 along the upper wall joint 244 of the rear bracket 24 to allow access for the joining means for joining the rear flange portion 226 of the aforementioned rear floor cross member 22 to the flat joint portion 162 of the rear floor tunnel 16.

[0058] In a preferred embodiment, the rear bracket 24, together with the seat bracket 27, is pre-joined to the rear floor cross member 22 to form the rear floor cross member assembly (22, 24, 27), and when this rear floor cross member assembly is joined to the rear portion of the floor formed by the floor panels 10, 10 and the rear floor tunnel 16, the rear flange portion 226 covered by the rear bracket 24 becomes accessible to a joining means through the opening 240. Possible joining means include, for example, a spot welding gun for performing resistance spot welding or a laser beam for performing laser spot welding.

[0059] The seat bracket 27 is configured in a box shape having a front wall 271, a rear wall 272, side walls 273, 274, and an upper wall 277, and is joined to the front wall 221 and rear wall 222 of the rear floor cross member 22 at the lower parts of the front wall 271 and rear wall 272, and to the upper wall 224 of the rear floor cross member 22 at the flange portions at the lower parts of the side walls 273, 274.

[0060] 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 25, 26, 27, and 28.

[0061] 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.

[0062] The floor center panel 15 is formed with a plurality of reinforcing beads extending parallel to the vehicle length direction. In the illustrated example, concave beads are formed, but convex beads may also be formed. Forming such reinforcing beads ensures the surface rigidity of the floor center panel 15, and has the advantage that a reinforcing structure extending in the vehicle length direction can be formed in the center of the vehicle width direction of the vehicle floor as a structural element in place of the floor tunnel between the front floor tunnel 13 and the rear floor tunnel 16.

[0063] (Main components and effects) As described above, the vehicle body floor structure of the present invention is configured such that the front floor cross-member 21, which extends seamlessly across the entire width of the vehicle compartment floor, intersects with the rear end (14) of the front floor tunnel 13 and the two are rigidly connected to each other at this intersection, and the rear floor cross-member 22, which extends seamlessly across the entire width of the vehicle compartment floor behind it, intersects with the front end (front end inclined portion 161, flat joint portion 162) of the rear floor tunnel 16 and the two are rigidly connected to each other at this intersection, thereby forming a highly rigid floor structure and being advantageous in preventing vehicle body deformation during a collision, etc.

[0064] In addition, a storage space surrounded by highly rigid members is secured on the floor between the front floor cross member 21 and the rear floor cross member 22, which are connected to the body frame member (12) at both ends in the vehicle width direction, making it suitable for use as a battery mounting space.

[0065] Furthermore, due to the configuration in which the front floor cross member 21 is positioned to intersect (overlap) the rear end (14) of the front floor tunnel 13 and the rear floor cross member 22 is positioned to intersect (overlap) the front end inclined portion 161 of the rear floor tunnel 16, the rear end (14) of the front floor tunnel 13 is extended to within the cross section of the front floor cross member 21, and the front end inclined portion 161 of the rear floor tunnel 16 is extended to within the cross section of the rear floor cross member 22.Compared to a configuration in which they do not intersect, the space under the front tunnel 130 is expanded rearward and the space under the rear floor 160 is expanded forward, thereby improving the utilization efficiency of the space inside the vehicle cabin.

[0066] For example, as shown in FIG. 3, when an exhaust gas purification device 81 (catalytic converter) or a sub-muffler of the exhaust system 8 is placed in the space under the front tunnel 130, it becomes easier to lay out the exhaust pipe 83 extending rearward from the exhaust gas purification device 81, and when a muffler 82 (main chamber) of the exhaust system 8 is placed in the space under the rear floor 160, it becomes easier to lay out the exhaust pipe 83 extending forward from the muffler 82.

[0067] Alternatively, compared to a non-intersecting configuration, the front floor cross member 21 can be positioned further forward and the rear floor cross member 22 can be positioned further rearward, thereby allowing the flat floor space 150 between the front floor cross member 21 and the rear floor cross member 22 to be expanded forward and rearward.

[0068] For example, as shown in Figure 3, 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 and rearward, which has the advantage of allowing a larger battery to be mounted. In this case, the amount of forward and rearward movement of the front floor cross member 21 and the rear floor cross member 22 is less than their forward and rearward width, but the floor space 150 is expanded forward and rearward across the entire width of the vehicle, resulting in a high space expansion efficiency.

[0069] Furthermore, the configuration includes a front edge portion 155 joined to the rear edge portion 145 of the front floor tunnel 13, a rear edge portion 156 joined to the front edge portion 165 of the rear floor tunnel 16, and a substantially flat floor center panel 15 extending between the front edge portion 155 and the rear edge portion 156, so that the left and right floor panels 10, 10 can utilize the existing vehicle body design in which the front and rear floor tunnels are connected, and has the advantage of being able to introduce a split structure for the front and rear floor tunnels with minimal design changes.

[0070] Furthermore, by making the floor center panel 15, which has less structural strength than the front and rear floor tunnels 13 (14), 16, a separate component from the left and right floor panels 10, 10, the thickness of the floor center panel 15 can be made greater than the thickness of the left and right floor panels 10, 10, which is advantageous in compensating for the reduced structural strength.

[0071] In a preferred embodiment of the present invention, a configuration is provided in which a rear bracket 24 is joined to connect an upper wall 164 adjacent to the front end inclined portion 161 of the rear floor tunnel 16 and an upper wall 224 of the rear floor cross member 22, which is advantageous in improving the connection strength and rigidity of the intersection between the rear floor tunnel 16 and the rear floor cross member 22.

[0072] In particular, the rear bracket 24 has side wall portions 242 on both sides that extend to fill the space defined between the rear floor cross member 22 and the rear floor tunnel 16 by the front inclined surface 163 of the upper wall 164, thereby rigidly connecting the rear floor cross member 22 and the rear floor tunnel 16 in three dimensions, thereby forming a robust vehicle floor structure at the rear of the vehicle floor in which the rear floor cross member 22 and the rear floor tunnel 16 are linked together.

[0073] In a preferred embodiment of the present invention, the front end of the rear floor tunnel 16 has a flat joint 162 to which the rear flange portion 226 of the rear floor cross member 22 is joined, which is formed in a stepped shape at a height intermediate between the upper wall 164 and the front edge portion 165 of the rear floor tunnel 16, and the rear flange portion 226 of the rear floor cross member 22 is formed at a higher position than the rear flange portions 227 which are joined to the floor surfaces located on both sides of the flat joint 162 of the rear floor tunnel 16 in the vehicle width direction, thereby advantageously enabling a joint structure in which the rear floor cross member 22 and the rear floor tunnel 16 intersect while leaving the cross section of the rear wall 222 of the rear floor cross member 22 intact.

[0074] In the above description, the shape expressed as flat may be substantially flat, and may include a case where there are some irregularities.

[0075] 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]

[0076] 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 24 Rear bracket 29 Rear floor cross member lower 130 Space under the front tunnel 131,132 side wall 133 Upper Wall 134 Side edge 135 Front end (of front floor tunnel) 141, 142 Side (leading edge) 143 Upper part (leading edge) 144 Side edge 145 Trailing edge 146 Tunnel rear wall 150 storage spaces 154 Side edge 155 (Floor center panel) front edge 156 Trailing edge 160 Rear underfloor space 161 Front end slope 162 Flat joint 164 Upper Wall 165 Leading edge joint 165e Base of leading edge 166 Side edge 211 Front wall 211a Remaining front wall 213 (Front floor cross member) upper wall 231 (Upper bracket) upper wall 232 (Upper bracket) front wall 233 (upper bracket) front edge 234 Side edge (of upper bracket) 243 (rear bracket) upper wall 244 Upper wall joint

Claims

1. A vehicle body floor structure, a floor panel that defines the floor surface of the vehicle compartment; a front 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 rear floor tunnel extending rearward in the vehicle length direction from a leading edge joint portion located rearward in the vehicle length direction with respect to the rear end portion of the front floor tunnel; front and rear floor cross members extending in the vehicle width direction on the floor panel, each including a front wall, a rear wall, an upper wall extending between the upper end of the front wall and the 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, and having a hat-shaped cross section, and connected to a vehicle body frame member at an end in the vehicle width direction, and the rear floor cross member is disposed rearward in the vehicle length direction with a gap therebetween relative to the front floor cross member; The rear floor cross member intersects with the upper side of the front end of the rear floor tunnel and extends in the vehicle width direction, forming a vehicle body floor structure.

2. The vehicle body floor structure according to claim 1 , further comprising a rear bracket joined to connect an upper wall of the rear floor tunnel and the upper wall of the rear floor cross member.

3. The vehicle floor structure of claim 2, wherein an opening is formed in the upper wall portion of the rear bracket to allow access for a joining means for joining the rear floor tunnel and the rear flange portion of the rear floor cross member.

4. 4. A vehicle floor structure as described in claim 3, wherein the flat joint to which the rear flange portion of the rear floor cross member is joined is formed in a stepped shape at a height intermediate between the leading edge joint portion of the rear floor tunnel and the upper wall of the rear floor tunnel.

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