Vehicle body rear structure

Abstract

The present application provides a vehicle body rear structure capable of reliably protecting a mounted object arranged below a front portion of a rear floor while suppressing an increase in the number of components and an increase in weight. The vehicle body rear portion includes a front floor, a rear floor, a pair of left and right lower side sills, and a front cross member. The upper surface of the rear floor is higher in height than the upper surface of the front floor. The front cross member connects a rear portion of the front floor and a front wall of the rear floor, and end portions on the outer sides in the vehicle width direction are joined to the left and right lower side sills. The front wall of the rear floor has a plurality of bent corner portions, and the plurality of bent corner portions have a side view shape bent into a substantially L shape. At least one of the bent corner portions forms a closed cross section extending along the vehicle width direction together with the front cross member in the height range of the left and right lower side sills.

Description

TECHNICAL FIELD

[0001] The present application relates to a vehicle body rear structure. BACKGROUND

[0002] As a vehicle body rear structure, a structure is known in which a rear floor panel having a higher upper surface height than a front floor panel is joined to the rear of the front floor panel in a manner so as to become a step, and a fuel tank is disposed below the front portion of the rear floor panel (see Japanese Patent Application Publication No. 2000-272544 (hereinafter referred to as Patent Document 1)).

[0003] In the vehicle body rear structure described in Patent Document 1, a front wall (a longitudinal wall) extending downwardly is provided at the front portion of the rear floor panel joined to the rear of the front floor panel, and a cross member forming a closed section extending in the vehicle width direction together with the front wall is joined to the rear (the rear portion) of the front wall. The end portions of the front wall and the cross member on the outer sides in the vehicle width direction are joined to the lower side rails that are the side portion frames of the passenger compartment. In the cross member, the central region is biased upwardly relative to the end portions on the outer sides in the vehicle width direction that are joined to the lower side rails.

[0004] In the vehicle body rear structure described in Patent Document 1, the fuel tank is disposed below the front portion of the rear floor panel, and the front side of the fuel tank is reinforced by the closed section formed by the front wall of the rear floor panel and the cross member. SUMMARY

[0005] The vehicle body rear structure described in Patent Document 1 incorporates the cross member in which the central region is biased upwardly at the rear of the front wall of the rear floor panel. Therefore, when an impact load is input to one of the lower side rails from one side of the vehicle, in order to reliably withstand the load, it is necessary to sufficiently increase the rigidity of the cross member itself and the peripheral region of the cross member. However, in the case where the wall thickness of the cross member is increased, there is a problem in that the weight of the vehicle is increased, and in the case where a further reinforcing structure is added to the peripheral region of the cross member, there are problems in that the weight of the vehicle is increased and the number of parts is increased.

[0006] The present application has been made in view of such circumstances, and one object thereof is to provide a vehicle body rear structure that can reliably protect a mounted object disposed below the front portion of a rear floor panel while suppressing an increase in the number of parts and an increase in weight.

[0007] In order to solve the above problems and achieve the above object, the present application adopts the following solutions.

[0008] (1) : The rear structure of a vehicle body according to one aspect of the present application includes a front floor panel; a rear floor panel disposed at a rear of the front floor panel and having an upper surface higher in height than an upper surface of the front floor panel; a pair of lower side members disposed at vehicle width direction outer sides of the front floor panel and the rear floor panel and extending substantially in a vehicle longitudinal direction; and a front cross member connecting a rear of the front floor panel and a front wall of the rear floor panel and having end portions at the vehicle width direction outer sides joined to the lower side members, wherein the front wall of the rear floor panel has a plurality of bent corner portions, the plurality of bent corner portions have side view shapes bent into substantially L shapes, and at least one of the bent corner portions forms, together with the front cross member, a closed section extending in the vehicle width direction within a height range of the lower side members.

[0009] With the above-described structure, the closed section formed by the bent corner portions of the rear floor panel and the front cross member is disposed so as to overlap the lower side members in the vertical direction in a side view. Therefore, when an impact load is input to one of the lower side members from one side of the vehicle, the impact load is efficiently transmitted in a linear manner to the other lower side member side through the closed section extending in the vehicle width direction formed by the bent corner portions of the rear floor panel and the front cross member. In this structure, the closed section that receives the impact load from the side is formed by the bent corner portions of the rear floor panel and the front cross member, and thus the increase in the number of members for reinforcement can be suppressed.

[0010] (2) : In the above-described aspect (1), the bent corner portions can be disposed in a plurality of numbers within a height range of the lower side members.

[0011] In this case, since the plurality of bent corner portions of the front wall are disposed within the height range of the lower side members, the impact load input to one of the lower side members from one side of the vehicle can be efficiently transmitted to the other lower side member side using the plurality of bent corner portions that are high in rigidity.

[0012] (3) : In the above-described aspect (2), the front wall can have a first bent corner portion within the height range of the lower side members and a second bent corner portion disposed above a rear of the first bent corner portion, the front cross member can have a rising wall rising upward from a rear of the front floor panel and a rearward projecting wall bent and extending rearward from an upper end portion of the rising wall, and the first bent corner portion and the second bent corner portion of the front wall can form the closed section by being joined to the rising wall and the rearward projecting wall of the front cross member.

[0013] In this case, the first bent corner portion below the front portion of the front wall and the second bent corner portion above the rear portion constitute the vicinity of the front lower corner portion and the vicinity of the rear upper corner portion of the closed section extending in the vehicle width direction. Therefore, the rigidity in the vehicle width direction of the closed section extending in the vehicle width direction in the height range of the lower side members to the upper side is further improved.

[0014] (4) In any one of the above aspects (1) to (3), the rear side frames extending toward the rear side of the vehicle can be arranged on the inner side in the vehicle width direction of each of the lower side members, the left and right edge portions on the outer side in the vehicle width direction of the upper wall of the rear floor can be joined to the corresponding left and right rear side frames, the left and right edge portions on the outer side in the vehicle width direction of the front wall of the rear floor can be joined to the corresponding left and right lower side members, and the bent corner portions arranged in the height range of the lower side members to the upper side can be arranged at least at positions on the inner side in the vehicle width direction than the rear side frames.

[0015] In this case, the impact load input to one of the lower side members from one side of the vehicle is transmitted to the other lower side member side through the rear side frames and the upper wall of the rear floor, and is linearly transmitted to the other lower side member side through the bent corner portions of the front wall of the rear floor arranged in the height range of the lower side members to the upper side. Therefore, in the case where this structure is employed, the area of the closed section extending in the vehicle width direction formed by the front wall of the rear floor and the front cross member can be suppressed from being enlarged, and the load transmission performance in the vehicle width direction can be improved at the same time.

[0016] (5) In the above aspect (4), the front wall of the rear floor can have a front wall main body wall extending upward from the lower side members at a position on the inner side in the vehicle width direction than the rear side frames, and a third bent corner portion connected to the upper wall of the rear floor can be arranged at an upper edge portion of the front wall main body wall.

[0017] In this case, the third bent corner portion is arranged at a position on the upward side than the lower side members in a manner of linking the left and right rear side frames, so that the impact load input to one of the lower side members from one side of the vehicle can also be dispersed to the third bent corner portion and transmitted to the other lower side member side. Therefore, the area of the closed section extending in the vehicle width direction formed by the front wall of the rear floor and the front cross member can be further reduced.

[0018] In the case where a rear seat setting portion is arranged on the upper wall of the rear floor, the input load from the rear seat can be efficiently supported to the left and right rear side frames through the third bent corner portion. Therefore, in the case where this structure is employed, the support rigidity of the rear seat can be improved.

[0019] (6) In the aspect (5) described above, the end region of the front wall main wall on the vehicle width direction outer side in the vehicle width direction central region can be offset to the vehicle front side.

[0020] In this case, the vehicle width direction central region of the front wall main wall is disposed close to the closed section extending in the vehicle width direction formed by the front wall and the front cross plate of the rear floor. Therefore, in the case where the installation portion of the rear seat is disposed on the upper wall of the rear floor, the load in the up-down direction input from the rear seat can be efficiently received by the closed section described above. Therefore, in the case where this structure is employed, the area of the closed section formed by the front wall and the front cross plate of the rear floor can be suppressed from being enlarged, and at the same time, the support rigidity of the rear seat is further improved.

[0021] (7) In the aspect (3) described above, a reinforcement plate extending in the vehicle width direction can be joined to the back surface of the closed section facing the front cross plate.

[0022] In this case, the rigidity of the closed section extending in the vehicle width direction formed by the front wall and the front cross plate of the rear floor can be improved by the reinforcement plate. Therefore, in the case where this structure is employed, the enlargement of the outer surface shape of the closed section formed by the front wall and the front cross plate of the rear floor can be suppressed.

[0023] (8) In the aspect (7) described above, a floor passage in which the rear end portion is combined with the wall of the front cross plate constituting the closed section can be disposed in the vehicle width direction central region of the front floor, and the reinforcement plate can be joined to the region in the front cross plate from the vicinity of the joint portion to the lower side beam on each of the left and right sides to the vicinity of the joint portion to the floor passage.

[0024] In this case, the portion of the front cross plate to which the floor passage is joined is rigidly improved by the floor passage. Therefore, the rigidity of the front cross plate from the vicinity of the joint portion to the lower side beam on each of the left and right sides to the vicinity of the joint portion to the floor passage is improved by the reinforcement plate. Therefore, in the case where this structure is employed, the impact load input from the lower side beam on one side to the lower side beam on the other side can be efficiently transmitted to the lower side beam on the other side with high rigidity.

[0025] Compared to the case where the reinforcement plate continuously extends from the lower side beam on one side to the lower side beam on the other side, the extension length of the reinforcement plate can be shortened, and the increase in the vehicle weight caused by the reinforcement plate can be suppressed.

[0026] (9) In the aspect (6) described above, the end portion on the vehicle width direction outer side of the front cross member can be provided with a flared portion in which the front surface of the vehicle width direction central region of the front wall main body wall of the rear floor panel is enlarged toward the rear side of the vehicle, and an inclined surface that is inclined low in front and high in back between an upper ridge line and a lower ridge line extending in the vehicle width direction can be provided on the upper surface side of the flared portion, and the upper ridge line and the lower ridge line can extend to a position overlapping the bent corner portion in the front wall of the rear floor panel in a height range above and below the lower side frame in the vehicle width direction.

[0027] In this case, the upper ridge line and the lower ridge line provided on the flared portion on the vehicle width direction outer side of the front cross member overlap the bent corner portion of the rear floor panel in the vehicle width direction, and thus an impact load input to the lower side frame from one side of the vehicle is efficiently transmitted to the closed cross section formed by the bent corner portion of the rear floor panel and the front cross member via the upper ridge line and the lower ridge line of the flared portion. In this structure, the inclined surface that is low in front and high in back is provided on the upper surface side of the flared portion of the front cross member, and thus the foot space on the door opening side of the rear seat can be expanded, and the getting on and off performance of the rear seat occupant can be improved.

[0028] (10) In the aspect (1) described above, the closed cross section formed by the bent corner portion of the rear floor panel and the front cross member can be formed in a rectangular shape in which the length in the up-down direction is longer than the length in the front-rear direction.

[0029] In this case, when the installation portion of the rear seat is provided on the upper wall of the rear floor panel, a load in the up-down direction input from the rear seat side can be received with high rigidity via the closed cross section that is long in the up-down direction.

[0030] In the aspect of the present application, at least one of the bent corner portions of the front wall of the rear floor panel, together with the front cross member, constitutes a closed cross section extending in the vehicle width direction in a height range above and below the lower side frame. Thus, the increase in the number of components for reinforcement can be suppressed, and at the same time, an impact load input from one side of the vehicle can be efficiently transmitted to the other side of the vehicle. Therefore, in the aspect of the present application, the increase in the number of components and the increase in weight can be suppressed, and at the same time, the cargo installed below the front portion of the rear floor panel can be reliably protected. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a perspective view of the rear portion of the vehicle body of the vehicle of the embodiment as viewed from the upper side.

[0032] Figure 2 is a sectional view of Figure 1 along the line II-II.

[0033] Figure 3 is a III view of Figure 1 .

[0034] Figure 4 is a perspective view of the rear portion of the vehicle body of the vehicle of the embodiment viewed from the lower side. DETAILED DESCRIPTION

[0035] Hereinafter, an embodiment of the present application will be described based on the drawings. In the following description, as to the front-rear, up-down, left-right, unless specifically described, it means the orientation with respect to the advancing direction of the vehicle. An arrow FR directed to the front of the vehicle, an arrow UP directed to the upper of the vehicle, and an arrow LH directed to the left side of the vehicle are noted at appropriate portions of the drawings.

[0036] Figure 1 is a perspective view of the rear portion of the vehicle body of the vehicle 1 of the embodiment viewed from the front left obliquely upper side, Figure 2 is Figure 1 a sectional view along the line II-II of Figure 3 is Figure 1 a III view of

[0037] The symbol 10 in the drawing is a front floor panel disposed below the passenger compartment, and the symbol 11 is a rear floor panel disposed at the rear portion of the front floor panel 10. In Figure 1 , the main portion of the front floor panel 10 is indicated by an imaginary line.

[0038] The lower side of the passenger compartment is disposed with a lower side beam 12 as a skeletal frame extending along the vehicle body front-rear direction on both left and right sides. The front floor panel 10 is erected on the left and right lower side beams 12, and the lower surface side is supported by a plurality of floor panel frames 13, 14. The floor panel frames 13, 14 are formed in a hat-shaped cross-sectional shape opening upward, and the hat-shaped cross-section extends along the vehicle body front-rear direction. In the vehicle width direction inner side of the rear portion region of each of the left and right lower side beams 12, a rear side frame 30 extending toward the vehicle body rear side as a skeletal frame is joined. The rear portion region of the rear floor panel 11 is erected on the left and right rear side frames 30. The front portion region of the rear floor panel 11 is erected across the left and right lower side beams 12 and the rear side frames 30.

[0039] The above-described front floor panel 10, rear floor panel 11, lower side beam 12, and rear side frame 30 and the following-described main rear portion of the vehicle body constituting members are mainly formed of a metal material.

[0040] A floor panel passage 15 extending along the vehicle body front-rear direction is provided in the vehicle width direction center of the front floor panel 10. The floor panel passage 15 is formed in a substantially downwardly opening hat-shaped cross-sectional shape (substantially U-shaped), and the substantially downwardly opening hat-shaped cross-section extends along the vehicle body front-rear direction. The floor panel passage 15 is bulged upward with respect to the substantially flat base wall (substantially horizontally extending bottom wall) of the front floor panel 10. ​​

[0041] The upper surface of the rear floor panel 11 is set higher in its entirety than the height of the upper surface of the front floor panel 10. The rear floor panel 11 is provided with an upper bulging panel 11A arranged at the rear of the front floor panel 10 and a rear extending panel 11B engaged with the rear edge portion of the upper bulging panel 11A.

[0042] As shown in Figure 2 , the upper bulging panel 11A is provided with a rear flange 11Ar engaged with the front end portion of the rear extending panel 11B, an upper wall 11Au extending forward from the rear flange 11Ar toward the upper side and then extending forward substantially horizontally, and a front wall 11Af extending downward from the front end portion of the upper wall 11Au. A portion of the front wall 11Af of the upper bulging panel 11A is bulged upward more than the upper surface of the floor tunnel 15.

[0043] A fuel tank, not shown, is arranged below the front portion region of the upper bulging panel 11A. In the present embodiment, the fuel tank constitutes a mount carried below the front portion of the rear floor panel 11. However, the mount carried below the front portion of the rear floor panel 11 is not limited to the fuel tank, and may be, for example, a battery unit provided with a battery module and a control device that assumes electric power control, or the like.

[0044] As shown in Figure 1 , a side slope portion 11Aui extending downward toward the outer side in the vehicle width direction and an engagement flange 11Auf extending substantially horizontally from the lower end of the side slope portion 11Aui toward the outer side in the vehicle width direction are formed in the outer side region in the vehicle width direction of the upper wall 11Au of the upper bulging panel 11A. The engagement flange 11Auf is formed in a manner continuous with the rear flange 11Ar of the upper bulging panel 11A. Each of the left and right engagement flanges 11Auf is fixed by welding to the front portion region of the corresponding rear side frame 30. The central portion in the vehicle width direction of the upper wall 11Au of the upper bulging panel 11A is bulged upward. A rear seat, not shown, is provided on the upper surface of the central region in the vehicle width direction of the upper wall 11Au. Thus, the load of the rear seat and the seated person acts on the upper surface of the upper wall 11Au from the upper side.

[0045] As shown in Figure 2 , a rear cross panel 31 having a substantially hat-shaped cross section intersecting the vehicle width direction is engaged with the lower surface of the portion of the upper wall 11Au of the upper bulging panel 11A and the rear flange 11Ar. The rear cross panel 31 extends along the vehicle width direction, and the both end portions in the vehicle width direction are engaged with the left and right rear side frames 30. The rear cross panel 31 constitutes, together with the rear edge portion of the upper bulging panel 11A, a closed cross section 32 extending along the vehicle width direction.

[0046] Figure 4 is a perspective view of the upper bulging panel 11A and the front portion side region thereof as viewed from the front lower side. As shown in Figure 2 ,Figure 4 As shown, the front wall 11Af of the upper bulge plate 11A has a front wall main body wall 11Afa that bends downward from the front end of the upper wall 11Au. Two bent corner portions 41 and 42 are connected to the lower side of the front wall main body wall 11Afa, and the two bent corner portions 41 and 42 have a side-view shape that is bent into a roughly L-shape. One bent corner portion 41 is located at the lower position of the front side of the front wall 11Af, and the other bent corner portion 42 is located at the upper position of the front wall 11Af on the rearward side compared to the first bent corner portion 41. Hereinafter, the one bent corner portion 41 will be referred to as the "first bent corner portion 41", and the other bent corner portion 42 will be referred to as the "second bent corner portion 42".

[0047] The rear wall that rises above the second bend angle 42 is formed by the lower region of the front wall main body 11Afa. The first bend angle 41 and the second bend angle 42 extend continuously in the vehicle width direction, and the apex of their respective bends form an edge line extending in the vehicle width direction.

[0048] like Figure 2 As shown, the first bending angle 41 and the second bending angle 42 are positioned within the vertical height range of the left and right lower beams 12.

[0049] The rear end of the front floor plate 10 is connected to the front wall 11Af of the upper bulge plate 11A via a front cross plate 20 extending in the vehicle width direction. The front cross plate 20 includes: a front flange 20f that overlaps and engages with the rear edge of the front floor plate 10; an upright wall 20r that rises upward from the rear end of the front flange 20f (the rear part of the front floor plate 10); a rear extension wall 20e that bends and extends rearward from the upper end of the upright wall 20r; and an end flange 20ef that bends upward from the rear end of the rear extension wall 20e.

[0050] like Figure 2 As shown, the lower extension piece 41e of the first bent corner portion 41 in the front wall 11Af of the upper bulge plate 11A overlaps with the rear surface of the approximately central portion in the height direction of the erected wall 20r on the back side (rear surface), and is engaged with the lower extension piece 41e in this state. The rear edge of the rear extension wall 20e overlaps with the upper surface of the rear extension piece 42e of the second bent corner portion 42 in the front wall 11Af of the upper bulge plate 11A, and is engaged with the rear extension piece 42e in this state. The end flange 20ef overlaps with the lower front surface of the front wall main body wall 11Afa in the front wall 11Af of the upper bulge plate 11A, and is engaged with the front wall main body wall 11Afa in this state.

[0051] The front cross panel 20 is joined to the front wall 11Af of the upper bulging panel 11A in such a manner as to constitute, together with the front wall 11Af of the upper bulging panel 11A, a closed section 21 of a rectangular shape extending in the vehicle width direction. More specifically, the closed section 21 is formed in a rectangular shape in which the length in the up-down direction is longer than the length in the front-rear direction. The closed section 21 includes, at a portion thereof, the first bent corner portion 41 and the second bent corner portion 42, and is located in the entire height range of the upper and lower side frames 12.

[0052] The front flange 20f and the standing wall 20r of the central portion in the vehicle width direction of the front cross panel 20 are cut, and the rear end portion of the floor tunnel 15 is joined to the peripheral portion of the cut portion. As shown in Figure 1 、 Figure 3 A plurality of joining flanges 15f are provided at the rear end portion of the floor tunnel 15. These joining flanges 15f are joined to the standing wall 20r and the rearward extending wall 20e of the front cross panel 20.

[0053] A reinforcing panel 22 extending in the vehicle width direction is joined to the back surface (the back surface of the standing wall 20r and the rearward extending wall 20e) of the closed section 21 side of the front cross panel 20. The cross section of the reinforcing panel 22 intersecting the vehicle width direction is formed in a substantially L shape, and the reinforcing panel 22 is joined to the region of the front cross panel 20 near the joint portion to the respective lower side frames 12 and the joint portion to the floor tunnel 15.

[0054] A third bent corner portion 43 connected to the upper wall 11Au of the upper bulging panel 11A is provided at the upper edge portion of the front wall main body wall 11Afa in the front wall 11Af of the upper bulging panel 11A. The third bent corner portion 43 has a side view shape bent in a substantially L shape similarly to the first bent corner portion 41 and the second bent corner portion 42. The third bent corner portion 43 extends in the vehicle width direction in a manner following the shape of the front end portion of the upper wall 11Au of the upper bulging panel 11A. Therefore, the ridge line formed by the bent apex of the third bent corner portion 43 extends in the vehicle width direction in a manner following the shape of the front end portion of the upper wall 11Au.

[0055] As shown in Figure 1 、 Figure 3 In the front wall main body wall 11Afa of the upper bulging panel 11A, the central region in the vehicle width direction is bulged toward the front side with respect to the end portion region on the outside in the vehicle width direction. That is, the central region in the vehicle width direction of the front wall main body wall 11Afa is biased toward the front side of the vehicle with respect to the end portion region on the outside in the vehicle width direction. Due to this, the lower end of the central region in the vehicle width direction of the front wall main body wall 11Afa is disposed closer to the closed section 21 than the end portion region on the outside in the vehicle width direction.

[0056] The edges on the left and right on the outside in the vehicle width direction of the front wall 11Af of the upper bulging panel 11A are joined to the corresponding lower side frames 12 on the left and right, respectively. More specifically, as shown inFigure 4 As shown, the end portion of the front wall 11Af on the vehicle width direction outer side straddles the upper portion front surface side of the left and right corresponding rear side frames 30 in the vehicle width direction and is joined to the lower side sill 12. Figure 4 The symbol 23 in the drawing is a link bracket for joining the end portion of the front wall 11Af on the vehicle width direction outer side to the left and right corresponding rear side frames 30 and the lower side sill 12.

[0057] The first to third bent corner portions 41, 42, 43 formed by the front wall 11Af of the upper bulge panel 11A are continuously provided at least on the vehicle width direction inner side of the left and right rear side frames 30.

[0058] The flared portions 24 are formed on both end portions of the front cross panel 20 on the vehicle width direction outer side from the front surface of the erected wall 20r so as to be wider than the front surface of the vehicle width direction central region of the front wall main body wall 11Afa of the upper bulge panel 11A in the front-rear width direction (the front-rear width is enlarged toward the rear side of the vehicle). The flared portions 24 are formed on the vehicle width direction outer side of the upper bulge panel 11A in such a manner that a portion (rear portion) thereof is wrapped back toward the vehicle width direction outer side of the mounted article such as the fuel tank.

[0059] An inclined surface 25 that is inclined downward toward the front side is formed in the front side upper region of the left and right flared portions 24 of the front cross panel 20. The inclined surface 25 extends in such a manner that a portion of the erected wall 20r and the rearward extending wall 20e is obliquely cut, and upper and lower ridge lines 26u, 26l extending in the vehicle width direction are formed at the upper and lower end sides. In other words, the inclined surface 25 is inclined lower in front and higher in rear between the upper and lower ridge lines 26u, 26l.

[0060] The upper ridge line 26u extends linearly from the end portion on the vehicle width direction outer side of the flared portion 24 toward the inner side in the vehicle width direction and then extends obliquely toward the front side in such a manner as to approach the corner where the erected wall 20r and the rearward extending wall 20e intersect. The lower ridge line 26l extends linearly from the end portion on the vehicle width direction outer side of the flared portion 24 toward the inner side in the vehicle width direction and then extends obliquely toward the upper side in such a manner as to approach the corner where the erected wall 20r and the rearward extending wall 20e intersect. Thus, the inclined surface 25 extends at a constant width from the end portion on the vehicle width direction outer side toward the inner side in the vehicle width direction and then gradually reduces the front-rear width in such a manner that the upper and lower ridge lines 26u, 26l converge at the corner where the erected wall 20r and the rearward extending wall 20e intersect.

[0061] The upper and lower ridge lines 26u, 26l (inclined surface 25) of the left and right flared portions 24 extend to a position overlapping the first and second bent corner portions 41, 42 (bent corner portions disposed in the height range above and below the lower side sill 12) formed by the front wall 11Af of the upper bulge panel 11A (rear floor panel 11) in the vehicle width direction.

[0062] <Effects of Embodiments>

[0063] In the rear portion of the vehicle body of the vehicle 1 of the present embodiment, the bent corner portions (the first bent corner portion 41 and the second bent corner portion 42) of the front wall 11Af of the rear floor panel 11 (the upper bulged panel 11A) constitute, together with the front cross panel 20, a closed section 21 extending in the vehicle width direction in the height range of the lower side frames 12 on the left and right. Therefore, the closed section formed by the bent corner portions (the first bent corner portion 41 and the second bent corner portion 42) of the rear floor panel 11 and the front cross panel 20 is arranged so as to overlap the lower side frames 12 on the left and right in the vertical direction in a side view. As a result, when an impact load is input from one side of the vehicle 1 to one of the lower side frames 12, the impact load is efficiently transmitted to the other lower side frame 12 in a straight line shape by the closed section 21 extending in the vehicle width direction formed by the bent corner portions (the first bent corner portion 41 and the second bent corner portion 42) of the rear floor panel 11 and the front cross panel 20.

[0064] In the rear portion of the vehicle body of the vehicle 1 of the present embodiment, the closed section 21 that receives an impact load from the side is constituted by the bent corner portions (the first bent corner portion 41 and the second bent corner portion 42) of the rear floor panel 11 and the front cross panel 20, and thus the increase in the number of components for reinforcement can be suppressed.

[0065] Therefore, in the case where the rear portion structure of the vehicle body of the present embodiment is employed, the increase in the number of components and the increase in weight can be suppressed, and at the same time, the mounted object (for example, a fuel tank) arranged below the front portion of the rear floor panel 11 can be reliably protected.

[0066] In the present embodiment, the closed section 21 is constituted by the first bent corner portion 41 and the second bent corner portion 42 of the rear floor panel 11 arranged in the height range of the lower side frames 12 on the left and right, but the closed section 21 can also be a structure including only one bent corner portion or a structure including three or more bent corner portions.

[0067] However, in the case where the bent corner portions arranged in the height range of the lower side frames 12 on the left and right are provided as a plurality of (two or more) as in the present embodiment, the impact load input from one side of the vehicle 1 to one of the lower side frames 12 can be efficiently transmitted to the other lower side frame 12 in a straight line shape by the plurality of bent corner portions having high rigidity.

[0068] In the vehicle body rear portion of the vehicle 1 of the present embodiment, the front wall 11Af of the rear floor panel 11 (the upper bulged panel 11A) has the first bent corner portion 41 on the lower front side and the second bent corner portion 42 on the upper rear side in the height range of the left and right lower side frames 12. The front cross panel 20 has a rising wall 20r rising upward from the rear portion of the front floor panel 10 and a rearward extending wall 20e extending rearward from the upper end portion of the rising wall 20r. Also, the first bent corner portion 41 and the second bent corner portion 42 of the front wall 11Af of the rear floor panel 11 constitute the closed section 21 by being joined to the rising wall 20r and the rearward extending wall 20e of the front cross panel 20.

[0069] In the vehicle body rear portion structure of the present embodiment, the first bent corner portion 41 on the lower front side and the second bent corner portion 42 on the upper rear side of the front wall 11Af constitute the vicinity of the lower front corner portion and the vicinity of the upper rear corner portion of the closed section 21 extending in the vehicle width direction, and thus the rigidity in the vehicle width direction of the closed section 21 extending in the vehicle width direction in the height range of the left and right lower side frames 12 can be further improved.

[0070] In the vehicle body rear portion of the vehicle 1 of the present embodiment, the edge portion on the vehicle width direction outer side of the upper wall 11Au of the rear floor panel 11 (the upper bulged panel 11A) is joined to the corresponding rear side frame 30 on the left and right, and the edge portion on the vehicle width direction outer side of the front wall 11Af of the rear floor panel 11 (the upper bulged panel 11A) is joined to the corresponding lower side frame 12 on the left and right. Also, the first bent corner portion 41 and the second bent corner portion 42 disposed in the height range of the left and right lower side frames 12 are disposed at least at positions on the vehicle width direction inner side than the rear side frame 30.

[0071] With this structure, the impact load input to one of the left and right lower side frames 12 from one side of the vehicle 1 is transmitted to the other lower side frame 12 side through the rear side frame 30 and the upper wall 11Au of the rear floor panel 11, and is linearly transmitted to the other lower side frame 12 side through the first bent corner portion 41 and the second bent corner portion 42 of the front wall 11Af of the rear floor panel 11.

[0072] Therefore, in the case where the vehicle body rear portion structure of the present embodiment is employed, the enlargement of the area of the closed section 21 extending in the vehicle width direction formed by the front wall 11Af of the rear floor panel 11 and the front cross panel 20 can be suppressed, and at the same time, the load transmission performance in the vehicle width direction can be improved.

[0073] Further, in the vehicle body rear portion of the vehicle 1 of the present embodiment, the front wall 11Af of the rear floor 11 has a front wall main wall 11Afa extending upward from a position on the inner side in the vehicle width direction than the rear side frame 30. Further, a third bent corner portion 43 is provided at an upper edge portion of the front wall main wall 11Afa, which is connected to the upper wall 11Au of the rear floor 11. Therefore, the third bent corner portion 43 is arranged at a position on the upper side than the lower side beam 12 in a manner of linking the left and right rear side frames 30. As a result, the impact load input from one side of the vehicle 1 to the lower side beam 12 on one side is also dispersed to the third bent corner portion 43 and transmitted to the lower side beam 12 on the other side.

[0074] Therefore, in the case where the vehicle body rear portion structure of the present embodiment is adopted, the area of the closed section 21 formed by the front wall 11Af of the rear floor 11 and the front cross plate 20 can be further reduced.

[0075] In the case where the present structure is adopted, the seat load input from the rear seat to the upper wall 11Au of the rear floor 11 is efficiently supported to the left and right rear side frames 30 through the third bent corner portion 43. In particular, the third bent corner portion 43 is inclined downward toward the outer side in the vehicle width direction in a manner of following the side inclined portion 11Aui of the front wall 11Af of the rear floor 11, and thus the seat load input to the upper wall 11Au can be more efficiently transmitted to the left and right rear side frames 30.

[0076] Therefore, in the case where the present structure is adopted, the support rigidity of the rear seat can also be sufficiently improved.

[0077] In the vehicle body rear portion of the vehicle 1 of the present embodiment, the vehicle width direction central region of the front wall main wall 11Afa of the rear floor 11 (upper bulging plate 11A) is biased to the vehicle front side in plan view than the end region on the outer side in the vehicle width direction. Thereby, the lower end of the vehicle width direction central region of the front wall main wall 11Afa is arranged close to the closed section 21 extending in the vehicle width direction. Therefore, the upward and downward seat load input from the rear seat can be efficiently received by the closed section 21 extending in the vehicle width direction.

[0078] Therefore, in the case where the vehicle body rear portion structure of the present embodiment is adopted, the area of the closed section 21 formed by the front wall 11Af of the rear floor 11 and the front cross plate 20 can be suppressed from being enlarged, and at the same time, the support rigidity of the rear seat can be further improved.

[0079] In the vehicle body rear portion of the vehicle 1 of the present embodiment, the reinforcing plate 22 extending in the vehicle width direction is joined to the rear surface of the closed section 21 facing the front cross plate 20, and thus the rigidity of the closed section 21 formed by the front wall 11Af of the rear floor 11 and the front cross plate 20 can be improved by the reinforcing plate 22. In particular, in the present embodiment, the reinforcing plate 22 is formed in a substantially L-shaped cross section, and the reinforcing plate 22 is joined across the erected wall 20r and the rearward extending wall 20e of the front cross plate 20. Thus, the rigidity of the closed section 21 can be improved more efficiently.

[0080] Therefore, with the present structure, the rigidity can be sufficiently ensured, and at the same time, the enlargement of the outer surface shape of the closed section 21 formed by the front wall 11Af of the rear floor 11 and the front cross plate 20 can be suppressed.

[0081] In the structure of the vehicle body rear portion of the present embodiment, the reinforcing plate 22 is joined to the region of the front cross plate 20 near the joint portion to the bottom plate tunnel 15 from the joint portion to each of the left and right lower side members 12. Thus, the rigidity between the left and right lower side members 12 and the near portion of the bottom plate tunnel 15 in the front cross plate 20 is improved efficiently by the reinforcing plate 22. Therefore, with the present structure, the impact load input to one of the lower side members 12 from one side of the vehicle 1 can be transmitted to the other lower side member 12 side with high rigidity more efficiently.

[0082] Further, the structure of the present embodiment is not a structure in which the reinforcing plate 22 continuously extends from one of the lower side members 12 to the other lower side member 12, and thus the extension length of the reinforcing plate 22 can be shortened, and the increase in the vehicle weight caused by the reinforcing plate 22 can be suppressed.

[0083] In the vehicle body rear portion of the vehicle 1 of the present embodiment, the flared portion 24 in which the front surface of the vehicle width direction central region of the front wall main wall 11Afa of the rear floor 11 is expanded toward the rear side of the vehicle is provided at the end portion of the front cross plate 20 on the vehicle width direction outer side. Further, the inclined surface 25 inclined forwardly low and rearwardly high between the upper ridge line 26u and the lower ridge line 26l extending in the vehicle width direction is provided on the upper surface side of the flared portion 24, and the upper ridge line 26u and the lower ridge line 26l extend to the positions overlapping the first bent corner portion 41 and the second bent corner portion 42 in the front wall 11Af of the rear floor 11 in the vehicle width direction.

[0084] In the present structure, the upper ridge line 26u and the lower ridge line 26l provided at the flared portion 24 overlap the first bent corner portion 41 and the second bent corner portion 42 of the rear floor 11 in the vehicle width direction, and thus the impact load input to one of the lower side members 12 from one side of the vehicle 1 can be transmitted to the closed section 21 extending in the vehicle width direction through the upper ridge line 26u and the lower ridge line 26l more efficiently.

[0085] In the case of the present embodiment, the inclined surface 25 extends at a constant width from the end portion on the vehicle width direction outer side toward the vehicle width direction inner side, and then the upper ridge line 26u and the lower ridge line 26l gradually reduce the front-rear width in a manner that converges at the corner where the rise wall 20r and the rearward extending wall 20e intersect. Therefore, it is possible to efficiently transmit the impact load input from the side sill 12 on one side of the vehicle 1 to the corner where the rise wall 20r and the rearward extending wall 20e intersect through the upper ridge line 26u and the lower ridge line 26l.

[0086] Further, in the vehicle body rear structure of the present embodiment, the inclined surface 25 that is low in front and high in rear is provided on the upper surface side of the flared portion 24 of the front cross plate 20, and therefore it is possible to expand the foot space on the door opening side of the rear seat and improve the getting-on and off performance of the rear seat occupant.

[0087] In the vehicle body rear of the vehicle 1 of the present embodiment, the closed section 21 formed by the first bent corner portion 41, the second bent corner portion 42 of the rear floor panel 11, and the front cross plate 20 is formed in a rectangular shape in which the length in the up-down direction is longer than the length in the front-rear direction. Therefore, it is possible to receive the load in the up-down direction input from the rear seat on the upper wall 11Au of the rear floor panel 11 with high rigidity through the closed section 21 that is long in the up-down direction.

[0088] Therefore, in the case where the present structure is employed, it is possible to further improve the support rigidity of the rear seat.

[0089] The present application is not limited to the above-described embodiments, and various design changes can be made within the scope of the gist thereof.

[0090] For example, in the above-described embodiments, the rear floor panel 11 is composed of two members, the upper flared panel 11A and the rearward extending panel 11B, but the rear floor panel 11 can also be composed of one panel. The rear floor panel 11 can also be composed of three or more panel members.

Claims

1. A rear structure of a vehicle body, characterized in that, The rear structure of the vehicle body includes: Front floor; A rear floor plate, which is disposed at the rear of the front floor plate, and whose upper surface is higher than the upper surface of the front floor plate; A pair of lower side beams on the left and right sides are located on the outer side of the front floor and the rear floor in the vehicle width direction and extend approximately along the front-rear direction of the vehicle body. as well as A front crossbar connects the rear portion of the front floor plate to the front wall of the rear floor plate, and its outer end in the vehicle width direction is attached to the left and right lower side beams. The front wall of the rear base plate has multiple bends, which are bent into an approximately L-shaped side view. At least one of the bent corners, together with the front cross plate, forms a closed section extending along the vehicle width direction within the vertical height range of the left and right lower side beams.

2. The rear structure of the vehicle body according to claim 1, characterized in that, The bending angle is provided in multiple ways within the vertical height range of the lower side beam on the left and right.

3. The rear structure of the vehicle body according to claim 2, characterized in that, The front wall has a first bend angle portion and a second bend angle portion disposed on the upper rear side of the lower side beam within the vertical height range of the left and right lower side beams. The front cross plate has an upright wall that rises upward from the rear of the front base plate and a rearward extending wall that bends backward from the upper end of the upright wall. The first and second bends of the front wall form the closed section by joining the upright wall and the rear extension wall to the front cross plate.

4. The rear structure of the vehicle body according to any one of claims 1 to 3, characterized in that, Rear side frames extending toward the rear of the vehicle are arranged on the inner side of each of the left and right lower side beams in the vehicle width direction. The left and right edges of the upper wall of the rear floor plate in the vehicle width direction are respectively joined to the corresponding left and right rear side frames. The left and right edges of the outer side of the front wall of the rear floor plate in the vehicle width direction are respectively joined to the corresponding left and right lower side beams. The bending angle portion, which is configured within the vertical height range of the left and right lower side beams, is positioned at least on the inside side of the rear side frame in the vehicle width direction.

5. The rear structure of the vehicle body according to claim 4, characterized in that, The front wall of the rear floor plate has a main front wall extending upward from the lower side beam at a position inside the rear side frame in the vehicle width direction. A third bent corner portion connected to the upper wall of the rear bottom plate is provided at the upper edge of the front wall main body.

6. The rear structure of the vehicle body according to claim 5, characterized in that, When viewed from above, the central region of the main front wall in the vehicle width direction is offset towards the front of the vehicle relative to the outer end region in the vehicle width direction.

7. The rear structure of the vehicle body according to claim 3, characterized in that, A reinforcing plate extending along the vehicle width direction is joined to the back side of the front cross plate facing the closed section.

8. The rear structure of the vehicle body according to claim 7, characterized in that, A floor plate channel is provided at the center of the front floor plate in the vehicle width direction, the rear end of which is connected to the wall of the front cross plate forming the closed section. The reinforcing plate is joined in the area near the joint of the front cross plate from the joint with the left and right lower side beams to the joint with the bottom plate channel.

9. The rear structure of the vehicle body according to claim 6, characterized in that, An expansion portion is provided at the outer end of the front cross plate in the vehicle width direction, the front surface of which is wider than the central area of ​​the front wall main body of the rear bottom plate in the vehicle width direction, and extends towards the rear of the vehicle. An inclined surface is provided on the upper surface of the extended portion, which slopes downwards from front to rear between an upper edge line and a lower edge line extending along the vehicle width direction. The upper edge line and the lower edge line extend to a position in the vehicle width direction that overlaps with the bending angle portion disposed in the front wall of the rear floor plate within the height range above and below the lower side beam.

10. The rear structure of the vehicle body according to claim 1, characterized in that, The closed cross section formed by the bent corner of the rear bottom plate and the front cross plate is a rectangular shape whose length in the vertical direction is longer than its length in the front-back direction.

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