Vehicle body rear structure

Abstract

Provided is a vehicle body rear structure that is simple in configuration while not occupying a large space, and that is capable of suppressing movement of a spare tire in the direction of a fuel tank at the time of input of an impact load. The vehicle body rear structure includes a vehicle body floor (2) and a fuel tank (6). The vehicle body floor (2) has a tire housing portion (15) that is recessed downward. The fuel tank (6) is supported on a lower surface of the vehicle body floor (2) on a front side of the tire housing portion (15). A reinforcement member (14) is installed at a position in front of the tire housing portion (15) of the vehicle body floor (2). The reinforcement member (14) extends in a vehicle body front-rear direction, and serves to reinforce an upper region of the fuel tank (6) of the vehicle body floor (2).

Description

Technical Field

[0001] This invention relates to a rear vehicle structure in which a tire storage section is provided at the rear of the vehicle chassis. Background Technology

[0002] In recent years, a large number of vehicles have been produced with fuel tanks located under the chassis and under the rear seats.

[0003] Furthermore, in this type of vehicle, there are known vehicles with a tire disc located at the rear of the chassis. The tire storage portion of the tire disc is formed in a downward recessed manner behind the fuel tank mounting portion, and a spare tire is stored in this tire storage portion. The bottom of the tire storage portion partially overlaps with the fuel tank located below the chassis in the vertical direction.

[0004] In such vehicles, there is a concern that when an impact load is applied from the rear of the vehicle, the tire disc may deform towards the front of the vehicle body, causing the spare tire, which is stored in the tire disc as a weight, to move towards the fuel tank. As a countermeasure, a rear vehicle body structure has been developed: a crossbeam extending along the vehicle width direction is arranged between the tire storage part of the tire disc and the fuel tank, and the crossbeam is used to restrict the forward movement of the spare tire (see, for example, Japanese Patent Application Publication Nos. 2016-20190). Summary of the Invention

[0005] However, the aforementioned rear vehicle structure uses a crossbeam, which is a large structural component, to restrict the forward movement of the spare tire. Therefore, depending on the vehicle, sometimes the large crossbeam cannot be positioned between the fuel tank and the tire storage area due to its configuration with other components. Therefore, it is desirable to develop a rear vehicle structure that can suppress the movement of the spare tire towards the fuel tank during impact load input without using a crossbeam, which is a large structural component.

[0006] The present invention provides a rear vehicle structure that, while having a simple structure that does not occupy much space, can suppress the movement of the spare tire toward the fuel tank when an impact load is input.

[0007] One embodiment of the present invention provides a rear vehicle structure comprising: a vehicle chassis having a downwardly recessed tire housing; and a fuel tank supported on a lower surface of the vehicle chassis located in front of the tire housing, wherein a reinforcing member is mounted in front of the tire housing on the vehicle chassis, the reinforcing member extending along the longitudinal direction of the vehicle body to reinforce the upper region of the fuel tank of the vehicle chassis.

[0008] Based on the above configuration, the area above the fuel tank of the vehicle chassis is reinforced by a stiffener extending along the longitudinal direction of the vehicle body. This increases the longitudinal rigidity of the area above the fuel tank in the vehicle chassis. Consequently, when an impact load is applied from the rear of the vehicle, deformation of the area above the fuel tank is suppressed, and movement of the spare tire toward the fuel tank is also inhibited.

[0009] Alternatively, the rear end of the reinforcement may extend to a position further rearward than the rear end of the fuel tank on the vehicle body side.

[0010] In this configuration, the reinforcement portion, strengthened by the chassis reinforcement, extends to a position further rearward than the rear end of the fuel tank. Therefore, when an impact load is applied from the rear of the vehicle, the reinforcement portion can be used to suppress deformation of the upper rear portion of the fuel tank in the chassis. Consequently, with this configuration, the load acting on the fuel tank can be suppressed more reliably when an impact load is applied from the rear of the vehicle.

[0011] Alternatively, the vehicle chassis may have: a tire disc having the tire storage portion; and a rear floor extending forward from the front portion of the tire disc, the front end of the tire disc engaging with the rear end of the rear floor, and the rear end of the reinforcement engaging with the engagement portion between the tire disc and the rear floor.

[0012] In this configuration, the rear end of the reinforcement engages with the joint between the tire disc and the rear floor. Therefore, the reinforcement can be used to increase the rigidity of the joint between the tire disc and the rear floor, and the impact load input via the tire disc can be efficiently distributed and supported by the reinforcement. This prevents stress concentration at the joint between the tire disc and the rear floor when an impact load is input from the rear of the vehicle, thus preventing large deformation of the joint and subsequent forward displacement of the tire disc.

[0013] Alternatively, a piping through hole may be formed in the rear floor, through which a piping extending from the fuel tank passes, and the front end of the reinforcement extends to a position overlapping the piping through hole in the longitudinal direction of the vehicle body.

[0014] In this situation, when an impact load is applied from the rear of the vehicle, the reinforcement can be used to suppress stress concentration around the pipe penetration hole. Therefore, excessive deformation of the rear floor during impact load application can be prevented.

[0015] Alternatively, the reinforcement may have: a front and rear extension that extends generally horizontally along the front and rear direction of the vehicle body; and an inclined portion that extends downwardly from the front end of the front and rear extension toward the front side of the vehicle body.

[0016] In this scenario, when an impact load is applied from behind the vehicle, the forward moving load of the spare tire acts on the rear ends of the front and rear extensions of the reinforcement, widening the angle between the front and rear extensions and the inclined portion, causing the rear end of the reinforcement to lift upwards. As a result, the front part of the spare tire moves upwards following the lifting displacement of the reinforcement, thus suppressing the movement of the spare tire towards the fuel tank.

[0017] Alternatively, a reinforcing rib may be formed on the inclined portion along the extending direction of the inclined portion.

[0018] In this case, the stiffeners of the reinforcing member are reinforced to improve the rigidity of the inclined portion. This allows for improved bending rigidity of the inclined portion while avoiding an increase in the cross-sectional area of ​​the reinforcing member. Therefore, with this configuration, it is possible to more reliably suppress the movement of the spare tire towards the fuel tank during impact load input while suppressing an increase in the area occupied by the reinforcing member.

[0019] Alternatively, the reinforcement member may be positioned at an end that is wider than the outer end of the tire housing in the vehicle width direction but closer to the inner end in the vehicle width direction.

[0020] In this case, the reinforcement is positioned in front of the area where the spare tire is located within the tire housing. Therefore, when an impact load is applied from the rear of the vehicle, the reinforcement can reliably absorb the load of the forward-moving spare tire, suppressing deformation of the area above the fuel tank in the vehicle chassis.

[0021] Alternatively, a crossbeam extending along the vehicle width direction may be joined at the position in front of the tire storage portion on the upper surface of the vehicle chassis, and the reinforcement member may be joined to the lower surface of the vehicle chassis at the position where it intersects with the crossbeam.

[0022] In this situation, when an impact load is applied to the reinforcement from the rear of the vehicle, the load is absorbed by the crossbeam on the upper surface of the chassis. As a result, deformation in the area above the fuel tank in the chassis is more reliably suppressed, and the input of impact loads to the fuel tank is inhibited.

[0023] Alternatively, a partition member that reinforces the closed section from the inside is installed at the position where it intersects with the reinforcement member in the closed section along the vehicle width direction formed by the crossbeam and the vehicle chassis, and the outer end of the crossbeam in the vehicle width direction is joined to a reinforcing beam extending upward along the rear wheel arch.

[0024] In this configuration, the portion of the crossbeam that intersects with the reinforcement is strengthened by a partition member, and the outer end of the crossbeam in the vehicle width direction is supported by a reinforcing beam. This allows impact loads input from the rear of the vehicle to the reinforcement to be efficiently transferred to the side of the vehicle body via the crossbeam. Consequently, when impact loads are input from the rear of the vehicle, the load input to the reinforcement can be absorbed with high rigidity over a wide range of the vehicle body, more reliably suppressing deformation in the area above the fuel tank in the chassis.

[0025] Alternatively, a fastener bracket for supporting the seat belt fastener may be installed on the front side of the vehicle body at the position where it intersects with the reinforcement in the crossbeam.

[0026] In this situation, when an impact load is applied from the rear of the vehicle, after a large load is applied from the seat belt to the seat belt fastener, this load is supported by a portion of the crossbeam whose rigidity is enhanced by reinforcements and partition members. Therefore, the situation where the area above the fuel tank of the vehicle chassis deforms significantly due to the forward movement load of the spare tire and the pull-out reaction force of the seat belt when an impact load is applied from the rear of the vehicle is suppressed.

[0027] Alternatively, a chassis reinforcing rib extending along the longitudinal direction of the vehicle body to the vicinity of the rear end of the reinforcing member can be formed between the front edge of the tire housing portion and the rear end of the reinforcing member in the vehicle chassis.

[0028] In this configuration, the rigidity (rigidity in the longitudinal direction) of the area between the leading edge of the tire housing and the reinforcement in the vehicle chassis is enhanced by the chassis reinforcing ribs. This suppresses the possibility of the area between the leading edge of the tire housing and the reinforcement crushing under the deformation load of the tire disc and the forward movement load of the spare tire when an impact load is applied from the rear of the vehicle. Furthermore, since the chassis reinforcing ribs extend near the rear end of the reinforcement, when a large load is applied from the rear of the vehicle, the rear part of the chassis reinforcing ribs bends upwards around its front end as a bending fulcrum when a large load is applied from the rear of the vehicle. This allows the front part of the spare tire to smoothly rise upwards, guided by the chassis reinforcing ribs. Consequently, movement of the spare tire towards the fuel tank is suppressed when an impact load is applied from the rear of the vehicle.

[0029] Alternatively, a stepped portion may be provided at the front edge of the tire storage portion, and the upper surface of the stepped portion may be higher than the upper surface of the bottom wall of the tire storage portion.

[0030] In this situation, when an impact load is applied from the rear of the vehicle, after the spare tire comes into contact with the rear end of the step, the leading edge of the tire storage section bends and deforms by lifting the rear corner of the step upwards. As a result, the front part of the spare tire, which is moving forward, is guided upwards by the step, and movement of the spare tire toward the fuel tank is suppressed.

[0031] In the rear vehicle structure of the present invention, a reinforcing member extending along the longitudinal direction of the vehicle body is installed in front of the tire disc of the vehicle chassis, and this reinforcing member strengthens the area above the fuel tank of the vehicle chassis. Therefore, the rear vehicle structure of the present invention, while having a simple structure that does not occupy a large space, can suppress the movement of the spare tire toward the fuel tank when an impact load is input by utilizing the reinforcement based on the reinforcing member. Attached Figure Description

[0032] Figure 1 This is a bottom view of the rear of the vehicle in the embodiment.

[0033] Figure 2 It is along Figure 1 A sectional view along line II-II.

[0034] Figure 3 This is a perspective view of the rear chassis portion of the vehicle as seen from above.

[0035] Figure 4 yes Figure 2 Enlarged view of part IV.

[0036] Figure 5 This is a partial sectional perspective view of the chassis reinforcing ribs in the embodiment.

[0037] Figure 6 This is a perspective view of the rear of the vehicle as described above.

[0038] Figure 7A This is a schematic cross-sectional view illustrating the deformation behavior of the rear of the vehicle in the embodiment.

[0039] Figure 7B This is a schematic cross-sectional view illustrating the deformation behavior of the rear of the vehicle in the embodiment.

[0040] Figure 7C This is a schematic cross-sectional view illustrating the deformation behavior of the rear of the vehicle in the embodiment. Detailed Implementation

[0041] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. It should be noted that, in appropriate locations in the drawings, arrow FR indicates the front of the vehicle, arrow UP indicates the top of the vehicle, and arrow LH indicates the left side of the vehicle.

[0042] Figure 1 This is a bottom view of the rear of vehicle 1 according to this embodiment. Figure 2 It is along Figure 1 A sectional view along line II-II. Additionally... Figure 3 This is a perspective view of the rear chassis 2 of vehicle 1 viewed from above.

[0043] The vehicle chassis 2 has a rear floor 10 located below the passenger compartment 3 and a tire disc 11 located below the trunk 5 behind the passenger compartment 3. A rear seat 4 (passenger seat) is positioned above the rear floor 10. The rear floor 10 extends from the front of the tire disc 11 towards the front of the vehicle. Rear side frames 12, generally extending along the longitudinal direction of the vehicle body, are positioned on the left and right sides of the rear floor 10 and the tire disc 11. The rear floor 10 and the tire disc 11 are supported by the left and right rear side frames 12.

[0044] Figure 2 , Figure 3 Reference numeral 7 in the attached drawing refers to a rear wheel cover that covers the inner side of the rear wheel (not shown), and reference numeral 8 refers to a reinforcing beam extending vertically along the inner side of the rear wheel cover 7. The reinforcing beam 8 is joined to the inner side of the rear wheel cover 7 and together with the rear wheel cover 7 forms a closed section extending vertically along the vehicle. The lower end of the reinforcing beam 8 is joined to the corresponding left and right rear side frames 12.

[0045] like Figure 2 As shown, the rear floor 10 has: a low portion 10a located below the seat cushion 4c of the rear seat 4; an inclined portion 10b extending obliquely upward and backward from the rear end of the low portion 10a; and a bulge 10c continuously formed with the upper region of the inclined portion 10b. The generally trapezoidal bulge shape of the bulge 10c extends over approximately the entire area in the vehicle width direction.

[0046] like Figure 3 As shown, a rear wall 10c-r, which slopes downwards towards the rear, is formed on the rear side of the bulge 10c, and a connecting flange 10c-f extends and bends from the lower end of the rear wall 10c-r toward the rear of the vehicle. The connecting flange 10c-f engages with the front extension wall 19 of the tire disc 11, which will be described later. A curved surface 23, which bends concavely toward the front of the vehicle body in the central region of the rear wall 10c-r (the rear of the bulge 10c), is provided on the rear wall 10c-r. The connecting flange 10c-f, located at the lower end of the curved surface 23, is curved along the curved surface 23 in a plan view.

[0047] It should be noted that the bulge 10c rises upward from the front of the front extension wall 19 of the tire disc 11 (described later) and extends generally along the vehicle width direction.

[0048] A fuel tank 6 is disposed below the portion spanning the lower section 10a, the inclined section 10b, and the bulge section 10c. The fuel tank 6 is formed with an upper surface shape that generally follows the shape of the lower surfaces of the lower section 10a, the inclined section 10b, and the bulge section 10c. The fuel tank 6 extends to the left and right sides, sandwiching the central area in the vehicle width direction, and is fixed to the lower part of the rear floor 10 by a fixing device (not shown). Thus, the fuel tank 6 is supported on the lower surface of the front side of the tire storage section 15, which will be described later in the vehicle chassis 2.

[0049] A pipe penetration hole 13 is formed in the central region of the inclined portion 10b of the rear floor 10 in the vehicle width direction. A fuel pipe (not shown) extending upward from the upper part of the fuel tank 6 passes through the pipe penetration hole 13. A pair of reinforcement members 14 are disposed on the lower surface of the rear floor 10 at a position outside the pipe penetration hole 13 in the vehicle width direction. The reinforcement members 14 extend along the longitudinal direction of the vehicle body and engage the lower surface of the region spanning from the bulge portion 10c to the rear end portion of the lower portion 10a. The front end of each reinforcement member 14 extends in the longitudinal direction of the vehicle body to a position overlapping with the pipe penetration hole 13. In addition, the rear end of each reinforcement member 14 extends to a position further rearward than the rear end position of the fuel tank 6. The reinforcement members 14 reinforce the area above the fuel tank 6 of the rear floor 10 (vehicle chassis 2) at a position in front of the tire storage portion 15 described later in the vehicle chassis 2. The detailed structure of the reinforcement members 14 will be described in detail later.

[0050] The tire disc 11 has a generally circular tire storage section 15 that is concave downwards. A spare tire 16 is stored in the tire storage section 15. The bottom wall 15a of the tire storage section 15 is as follows: Figure 2 As shown, it tilts downwards and toward the rear of the vehicle. A tire fixing part 17 is disposed approximately in the center of the bottom wall 15a of the tire storage section 15. In the tire fixing part 17, a fixing device (not shown) secures the center of the spare tire, which is tilted to the side and stored inside the tire storage section 15.

[0051] At the leading edge of the tire storage section 15 of the tire disc 11, a step 15b is provided, which is higher than the bottom wall 15a of the tire storage section 15. An upwardly extending wall 18 is provided at the front end of the step 15b. A forward extending wall 19, which extends generally horizontally forward, is provided at the upper end of the upward extending wall 18. The upward extending wall 18 extends in a generally straight line along the vehicle width direction. However, the upward extending wall 18 does not stand vertically upward as a whole, but rather tends to tilt upward towards the front of the vehicle body. The upward extending wall 18 and the forward extending wall 19 are connected by a smooth arc.

[0052] Here, the tire retaining part 17 within the tire storage section 15 is positioned further rearward than the raised wall 18. Therefore, when the spare tire 16, which is fixed to the tire retaining part 17 by an impact load input from the rear of the vehicle, is pressed upward and forward along the inclined bottom wall 15a, the front part of the spare tire 16 abuts against the vicinity of the corner of the rear end side of the step section 15b, causing the step section 15b to bend and deform in such a way that the corner is lifted upward (see reference). Figure 7A Then, as the spare tire 16 moves forward while maintaining this state, the front of the spare tire 16 abuts against a portion of the bent and deformed step 15b and the inclined upright wall 18, and is guided in an upward-standing manner (see reference). Figure 7B , 7C ).

[0053] Additionally, side extension walls 20, which are higher than the bottom wall 15a of the tire storage section 15, are provided on the left and right side edges of the tire storage section 15. The left and right side extension walls 20 are connected to the left and right opposite rear side frames 12.

[0054] The rear end of the rear floor 10 (the engaging flange 10c-f of the bulge 10c) overlaps on the upper surface of the front end of the front extension wall 19 of the tire disc 11, and the overlapping portions are joined together by welding or the like. Hereinafter, the portion where the tire disc 11 and the rear floor 10 are joined together will be referred to as the joint portion 21.

[0055] Multiple chassis reinforcing ribs 22 extending along the longitudinal direction of the vehicle body are formed on the front extension wall 19 of the tire disc 11. The multiple chassis reinforcing ribs 22 are arranged at approximately equal intervals in the vehicle width direction in the central region of the front extension wall 19 in the vehicle width direction. The upward bulging shape of each chassis reinforcing rib 22 extends along the longitudinal direction of the vehicle body.

[0056] Figure 4 yes Figure 2 Enlarged view of part IV. Figure 5 This is a partial sectional perspective view of chassis reinforcing rib 22. Figure 5 More specifically, it is a perspective view of the front extension wall 19 viewed from the rear of the vehicle body, with the rear portion of the front extension wall 19 cut off along the vehicle width direction and a chassis reinforcing rib 22 as the center.

[0057] like Figure 4 , Figure 5As shown, the cross-section of each chassis reinforcing rib 22 along the vehicle width direction is generally trapezoidal in shape, widening downwards at the ends. In the cross-section of each chassis reinforcing rib 22, except near the rear end, the width and height gradually decrease towards the front of the vehicle body (and gradually increase towards the rear of the vehicle body). The front end of each chassis reinforcing rib 22 extends to near the lower end of the rear side of the bulge 10c of the rear floor 10 (jointing flange 10c-f).

[0058] It should be noted that the rear ends of each chassis reinforcing rib 22 gradually decrease in width and height in the vehicle width direction as they move toward the rear of the vehicle body, while remaining continuous with the rear surface of the upper end of the upright wall 18.

[0059] like Figure 3 As shown, the central region of the lower rear end of the bulge 10c in the vehicle width direction has a curved shape that curves inward toward the front of the vehicle. Therefore, the extension length of each chassis reinforcing rib 22 toward the front of the vehicle body is longer the closer it is to the inside in the vehicle width direction. Thus, the chassis reinforcing rib 22 located on the inside in the vehicle width direction is longer in the longitudinal direction of the vehicle body compared to the chassis reinforcing rib 22 located on the outside in the vehicle width direction.

[0060] like Figure 1 As shown, the left and right chassis reinforcing ribs 22e (chassis reinforcing ribs 22) positioned on the outermost side in the vehicle width direction are arranged in a generally straight line (neatly arranged) overlapping with the left and right reinforcing members 14 in the longitudinal direction of the vehicle body. The reinforcing members 14 and the multiple chassis reinforcing ribs 22e sandwich the rear wall 10c-r of the bulge 10c of the rear floor 10. The reinforcing members 14 are positioned on the front side of the vehicle body, and the multiple chassis reinforcing ribs 22e are positioned on the rear side of the vehicle body. More specifically, the left and right reinforcing members 14 and the chassis reinforcing ribs 22e on the outermost side in the vehicle width direction are positioned at the front and rear ends of the curved surface 23 of the rear wall 10c-r in the vehicle width direction. The remaining chassis reinforcing ribs 22 are positioned at the rear of the inner region in the vehicle width direction of the curved surface 23 of the rear wall 10c-r. Furthermore, the front ends of the remaining chassis reinforcing ribs 22 are located on the front side of the vehicle body, closer to the rear ends of the left and right reinforcing members 14. That is, the front end of the remaining chassis reinforcing rib 22 overlaps with the rear end of the left and right reinforcing members 14 in the front-rear direction of the vehicle body.

[0061] Furthermore, the left and right chassis reinforcing ribs 22e, which are located furthest outward in the vehicle width direction, are positioned inward in the vehicle width direction from the left and right ends of the tire storage section 15. Therefore, all the chassis reinforcing ribs 22 on the front extension wall 19 are located on the moving track of the spare tire 16 within the tire storage section 15 when it moves forward.

[0062] It should be noted that, similar to the left and right chassis reinforcing ribs 22e located on the outermost side in the vehicle width direction, the left and right reinforcing members 14 are positioned on the inner side in the vehicle width direction of the left and right ends of the tire storage section 15. Therefore, the left and right reinforcing members 14 are located on the moving track when the spare tire 16 moves forward.

[0063] like Figure 1 , Figure 4 As shown, the reinforcement member 14 has a front and rear extension portion 24 that extends generally horizontally along the front-rear direction of the vehicle body, and an inclined portion 25 that extends downward from the front end of the front and rear extension portion 24 toward the front side of the vehicle body. The cross-sectional shape of the front and rear extension portion 24 and the inclined portion 25 along the vehicle width direction is generally top hat shaped. That is, in the front and rear extension portion 24 and the inclined portion 25, side flange portions 26fs that extend outward in the vehicle width direction are provided on the left and right edges of the concave-shaped portion 26a that is recessed downward. In addition, a rear flange portion 26fr that extends from the bottom wall of the concave-shaped portion 26a toward the rear side of the vehicle body is provided at the rear end of the front and rear extension portion 24.

[0064] The front and rear extensions 24 of each reinforcement member 14 engage with the lower surface of the bulge 10c of the rear floor 10, and the inclined portions 25 of each reinforcement member 14 engage with the lower surface of the inclined portion 10b and the rear lower surface of the low portion 10a of the rear floor 10. The front and rear extensions 24 and the inclined portions 25 engage with the lower surface of the rear floor 10 at the side flange 26fs and the rear flange 26fr. Thus, a continuous closed section is formed between the reinforcement member 14 and the rear floor 10 in the longitudinal direction of the vehicle body. This closed section bends along the inclined portion 25 and the front and rear extensions 24 of the reinforcement member 14, and the rear end abuts against the rear wall 10c-r of the bulge 10c.

[0065] Here, the chassis reinforcing ribs 22e, positioned on the outermost side in the vehicle width direction, extend to the vicinity of the rear ends of each of the left and right reinforcement members 14, sandwiching the rear wall 10c-r of the bulge 10c. The chassis reinforcing ribs 22e, whose front ends extend to the vicinity of the rear ends of the reinforcement members 14, are neatly arranged in a manner that overlaps with the front reinforcement members 14 in a generally straight line in the longitudinal direction. Furthermore, the longitudinal extensions 24 of each reinforcement member 14 extend generally horizontally at a height where at least a portion of the longitudinal extensions 24 of each reinforcement member 14 overlaps with the chassis reinforcing ribs 22 positioned on the rear side of each reinforcement member 14 in the vertical direction.

[0066] Here, the front end of the tire disc 11 and the rear end of the rear floor 10 are joined together at the joint 21 as described above. The rear flange 26fr of each reinforcement 14 is as follows... Figure 4As shown, it is inserted between the joint 21 of the tire disc 11 and the rear floor 10, and in this state, it is welded and fixed together with the tire disc 11 and the rear floor 10 in a three-layer overlapping state. That is, the rear end of each reinforcement 14 is engaged with the joint 21 of the tire disc 11 and the rear floor.

[0067] Additionally, on the bottom wall of the concave portion 26a of the inclined portion 25 of each reinforcement member 14, such as Figure 1 As shown, a reinforcing rib 27 is provided on the reinforcement member 14, which is recessed towards the upper side. The reinforcing rib 27 extends along the front-rear direction of the vehicle body (along the extension direction of the inclined portion 25) to improve the rigidity of the inclined portion 25 of the reinforcement member 14.

[0068] Figure 6 This is a three-dimensional view of the rear (chassis 2) of vehicle 1 viewed from the front and above.

[0069] like Figures 2-4 , Figure 6 As shown, a crossbeam 28 extending in the vehicle width direction is joined to the upper surface of the bulge 10c (located in front of the tire storage section 15) of the rear floor 10. The crossbeam 28 is formed in a generally top hat-shaped cross-section, with its front and rear flanges joining the upper surface of the bulge 10c. Thus, the crossbeam 28 and the bulge 10c (vehicle chassis 2) together form a closed cross-section in the vehicle width direction. The outer end of the crossbeam 28 in the vehicle width direction joins a reinforcing beam 8 extending upward along the rear wheel arch 7.

[0070] Each of the left and right reinforcement components 14, as shown Figure 6 As shown, it is joined to the lower surface of the rear floor 10 (vehicle chassis 2) at the position where it intersects with the crossbeam 28. At the position where it intersects with the reinforcement member 14 in the closed section formed by the crossbeam 28 and the bulge 10c (vehicle chassis 2), a partition member 29 (partition) is installed to reinforce the closed section from the inside.

[0071] In addition, such as Figure 6 As shown, a retainer bracket 30 is installed on the front side of the vehicle body at the position where it intersects with each of the reinforcements 14 in the crossbeam 28. The retainer bracket 30 is used to support the seat belt retainer for the rear seat 4.

[0072] Figures 7A-7C The deformation behavior of the rear of vehicle 1 when an impact load is applied from the rear is determined by... Figure 7A , Figure 7B , Figure 7C The schematic cross-sectional views are shown in sequence.

[0073] The following is for reference Figures 7A-7C This is used to illustrate the deformation behavior of the rear of the vehicle when an impact load is input.

[0074] <Deformation behavior of the rear of the vehicle>

[0075] Figure 7A As shown, when a large impact load F is applied from the rear of the tire disc 11, the tire housing 15 of the tire disc 11 is crushed and deformed along the longitudinal direction of the vehicle body, and the spare tire 16 inside the tire housing 15 is pressed forward. As a result, the front part of the spare tire 16 abuts against the rear surface of the step portion 15b at the leading edge of the tire housing 15, and the step portion 15b is bent and deformed by lifting its rear corner upwards. When the spare tire 16 is to move further forward, the front part of the spare tire 16 contacts the crushed and deformed step portion 15b and the forward-leaning upright wall 18, and the spare tire 16 is guided by gradually lifting its front part in interaction with the crushing deformation of the tire housing 15.

[0076] When the input of the impact load F further develops from this state, such as Figure 7B As shown, the front of the spare tire 16 abuts near the rear end of the front extension wall 19, and the impact load F is input to the rear of the front extension wall 19 via the spare tire 16. At this time, the central region of the front extension wall 19 in the vehicle width direction is reinforced by multiple chassis reinforcing ribs 22, so the front extension wall 19 is displaced with its rear end side raised upwards, starting from the vicinity of the joint 21 between it and the rear floor 10 on the front side. As a result, the spare tire 16 is guided with its front end raised further upwards.

[0077] At this time, when a larger load is input near the rear end of the front extension wall 19 via the spare tire 16, a deformation load is also input to the rear region of the rear floor 10. In the rear region of the rear floor 10, a pair of reinforcement members 14 are arranged in a manner along the longitudinal direction of the vehicle body, and each reinforcement member 14 has a structure with a front and rear extension 24 and an inclined portion 25. Therefore, as Figure 7C As shown, the rear end of the front and rear extensions 24 is raised in such a way that the bending angle between the front and rear extensions 24 and the inclined portion 25 of each of the reinforcements 14 is extended, and the rear end of the front extension wall 19 is further raised upward. As a result, the spare tire 16 is guided to stand upright with its front part raised further upward.

[0078] As described above, in vehicle 1 of this embodiment, when an impact load F is input from the rear of the vehicle, the energy of the impact load is absorbed by the deformation of the rear of the vehicle. During this process, the spare tire 16 exhibits an upward-standing behavior. Furthermore, by standing upward, the spare tire 16 is prevented from displacing towards the fuel tank 6 and the rear seat 4.

[0079] <Effects of the Implementation Method>

[0080] In the rear structure of this embodiment, a reinforcement member 14 extending along the longitudinal direction of the vehicle body is installed in front of the tire disc 11 of the vehicle chassis 2, thereby increasing the rigidity of the area above the fuel tank 6 of the vehicle chassis 2. Therefore, when an impact load is input from the rear of the vehicle, deformation of the area above the fuel tank 6 of the vehicle chassis 2 is suppressed, and movement of the spare tire 16 toward the fuel tank 6 is also suppressed. Thus, the rear structure of this embodiment, while possessing a simple configuration that does not occupy much space, can suppress movement of the spare tire 16 toward the fuel tank 6 when an impact load is input by utilizing the reinforcement based on the reinforcement member 14.

[0081] Furthermore, in the rear structure of this embodiment, the rear end of the reinforcement member 14 extends to a position further rearward than the rear end of the fuel tank 6. Therefore, when an impact load is applied from the rear of the vehicle, the reinforcement member 14 can be used to suppress deformation of the upper portion of the rear end of the fuel tank 6 in the vehicle chassis 2. Thus, with the rear structure of this embodiment, the load acting on the fuel tank 6 can be suppressed more reliably when an impact load is applied from the rear of the vehicle.

[0082] Furthermore, in the rear structure of this embodiment, the rear end of the reinforcement member 14 is engaged with the joint 21 between the tire disc 11 and the rear floor 10. Therefore, the rigidity of the joint 21 between the tire disc 11 and the rear floor 10 can be improved by using the reinforcement member 14, and the impact load input through the tire disc 11 can be distributed to the reinforcement member 14. Therefore, when the rear structure of this embodiment is adopted, the stress concentration at the joint 21 between the tire disc 11 and the rear floor 10 when an impact load is input from the rear of the vehicle can be suppressed, and the forward displacement of the tire disc 11 caused by deformation of the joint 21 can be suppressed.

[0083] It should be noted that in this embodiment, the vehicle chassis 2 is composed of a rear floor 10 and a tire disc 11, but the vehicle chassis 2 may also be composed of a single sheet of material including a tire storage section 15. Alternatively, the vehicle chassis 2 may be composed of three or more sheets of material.

[0084] Furthermore, in the rear structure of this embodiment, a pipe penetration hole 13 is provided in the rear floor 10, and the front end of the reinforcement 14 extends to a position overlapping the pipe penetration hole 13 in the longitudinal direction of the rear floor 10. Therefore, when an impact load is input from the rear of the vehicle, the reinforcement 14 can be used to suppress the stress concentration around the pipe penetration hole 13 in the rear floor 10. Thus, with this configuration, deformation of the rear floor 10 during the input of an impact load can be further suppressed, protecting the fuel tank 6.

[0085] Furthermore, in the rear structure of the vehicle body in this embodiment, the reinforcement 14 is configured to have: a front and rear extension 24 that extends substantially horizontally along the front-rear direction of the vehicle body; and an inclined portion 25 that slopes forward and downward from the front end of the front and rear extension 24. Therefore, when an impact load is input, when a large forward moving load of the spare tire 16 acts on the rear end of the front and rear extension 24 of the reinforcement 14, the angle between the front and rear extension 24 and the inclined portion 25 increases, and the rear end of the reinforcement 14 is lifted upward.

[0086] Furthermore, when the rear end of the reinforcement 14 is lifted upwards, the front of the spare tire is pushed further upwards. Therefore, with this configuration, movement of the spare tire 16 toward the fuel tank 6 can be more reliably suppressed when an impact load is input.

[0087] Furthermore, in the rear structure of the vehicle body of this embodiment, a reinforcing rib 27 along the extending direction of the inclined portion 25 is formed in the inclined portion 25 of the reinforcing member 14. Therefore, the bending rigidity of the inclined portion 25 can be improved while avoiding the enlargement of the cross-section of the reinforcing member 14. Therefore, with this configuration, the movement of the spare tire 16 toward the fuel tank 6 can be more reliably suppressed when an impact load is input, while suppressing the increase in the occupied area of ​​the reinforcing member 14.

[0088] Furthermore, in the rear structure of this embodiment, the reinforcement 14 is positioned on the inner side of the vehicle width direction, beyond the outer end of the tire housing 15 of the tire disc 11 in the tire width direction. Therefore, when the spare tire 16 is housed within the tire housing 15, the reinforcement 14 is located within the area projected forward onto the spare tire 16. Thus, when an impact load is input from the rear of the vehicle, the reinforcement 14 can reliably absorb the load of the forward-moving spare tire 16. Therefore, with this configuration, the reinforcement 14 can more reliably suppress the movement of the spare tire 16 toward the fuel tank 6 when an impact load is input.

[0089] Furthermore, in the rear structure of this embodiment, a crossbeam 28 extending along the vehicle width direction is joined at the position in front of the tire housing 15 on the upper surface of the vehicle chassis 2, and the reinforcement 14 is joined to the lower surface of the vehicle chassis 2 at the position where it intersects with the crossbeam 28. Therefore, when an impact load from the rear of the vehicle is input to the reinforcement 14, the load is absorbed by the crossbeam 28 on the upper surface side of the vehicle chassis 2. Therefore, with the rear structure of this embodiment, deformation of the area above the fuel tank 6 in the vehicle chassis 2 can be reliably limited, further suppressing the input of impact loads to the fuel tank 6.

[0090] Furthermore, in the rear structure of this embodiment, a partition member 29 is installed at the position where it intersects the reinforcement member 14 in the closed section along the vehicle width direction formed by the crossbeam 28 and the vehicle chassis 2. Therefore, the rigidity of the section at the position where it intersects the reinforcement member 14 in the closed section formed by the crossbeam 28 and the vehicle chassis 2 can be efficiently improved using the partition member 29. Moreover, in the rear structure of this embodiment, the outer end of the crossbeam 28 in the vehicle width direction is joined to a reinforcing beam 8 extending upward along the rear wheel arch 7. Therefore, impact loads input from the rear of the vehicle to the reinforcement member 14 can be efficiently and effectively transmitted to the side of the vehicle body via the crossbeam 28. Therefore, with this configuration, loads input to the reinforcement member 14 can be received with high rigidity, and deformation of the area above the fuel tank 6 in the vehicle chassis 2 can be more reliably suppressed.

[0091] Furthermore, in this embodiment, the rear structure of the vehicle body is configured such that a retainer bracket 30 is installed on the front side of the vehicle body at the position where it intersects with the reinforcement member 14 in the crossbeam 28, and the seat belt retainer of the rear seat 4 is supported on this retainer bracket 30. Therefore, when an impact load is input from the rear of the vehicle, after a large load is input from the seat belt to the seat belt retainer, this load is supported by a portion of the crossbeam 28 whose rigidity is increased by the reinforcement member 14 and the partition member 29. Therefore, with this configuration, the situation where the area above the fuel tank 6 in the vehicle chassis 2 deforms due to the large load input from the seat belt when an impact load is input can be suppressed.

[0092] Furthermore, in the rear structure of this embodiment, a chassis reinforcing rib 22 is provided between the leading edge of the tire housing 15 in the chassis 2 and the rear end of the reinforcement 14. This chassis reinforcing rib 22 extends along the longitudinal direction of the vehicle body to the vicinity of the rear end of the reinforcement 14. Therefore, the chassis reinforcing rib 22 increases the rigidity of the area between the leading edge of the tire housing 15 and the rear end of the reinforcement 14 in the chassis 2. As a result, when an impact load is input from the rear of the vehicle, the area between the leading edge of the tire housing 15 and the reinforcement 14 can be prevented from crushing and deforming due to the deformation load of the tire disc 11 and the forward movement load of the spare tire 16.

[0093] Furthermore, in the rear structure of this embodiment, the chassis reinforcing rib 22 extends to the vicinity of the rear end of the reinforcing member 14. Therefore, when an impact load is input from the rear of the vehicle, and the rear of the chassis reinforcing rib 22 bears a large load from the spare tire 16, the rear of the chassis reinforcing rib 22 lifts upward with its front end as the bending fulcrum. This behavior of the chassis reinforcing rib 22 guides the front of the spare tire 16 to stand upright. Therefore, with this configuration, it is possible to further suppress the movement of the spare tire 16 toward the fuel tank 6 when an impact load is input from the rear of the vehicle.

[0094] Furthermore, in the rear structure of this embodiment, a step portion 15b is provided at the leading edge of the tire storage portion 15 of the tire disc 11. The upper surface of the step portion 15b is higher than the upper surface of the bottom wall 15a of the tire storage portion 15. Therefore, when an impact load is input from the rear of the vehicle, after the spare tire 16 abuts against the rear end of the step portion 15b, the leading edge of the tire storage portion 15 bends and deforms by lifting the rear corner of the step portion 15b upwards. As a result, when an impact load is input from the rear of the vehicle, the front part of the spare tire 16, which is about to move forward, can be guided upwards by the step portion 15b, so that the spare tire 16 is displaced in an upright manner. Therefore, with this configuration, the movement of the spare tire 16 toward the fuel tank 6 when an impact load is input from the rear of the vehicle can be suppressed.

[0095] It should be noted that the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from its spirit.

Claims

1. A rear structure of a vehicle body, wherein, The rear structure of the vehicle body includes: The vehicle chassis has a downwardly recessed tire storage section; and The fuel tank is supported on the lower surface of the vehicle chassis located in front of the tire housing. A reinforcement member is installed at the front position of the tire storage section of the vehicle chassis. This reinforcement member extends along the longitudinal direction of the vehicle body and is used to reinforce the area above the fuel tank of the vehicle chassis. The rear end of the reinforcement extends to a position further rearward than the rear end of the fuel tank on the vehicle body side. The vehicle chassis has: A tire disc having the tire housing portion; and The rear floor extends forward from the front of the tire disc. The front end of the tire disc engages with the rear end of the rear floor. The rear end of the reinforcement is engaged at the junction of the tire disc and the rear floor. A crossbeam extending along the vehicle width direction is joined at the front position of the tire storage section on the upper surface of the vehicle chassis. The rear end of the reinforcement extends to a position on the rear side of the vehicle body, beyond the rear end of the crossbeam.

2. The rear structure of the vehicle body according to claim 1, wherein, The rear end of the fuel tank extends to a position further rearward than the rear end of the crossbeam on the vehicle body side.

3. The rear structure of the vehicle body according to claim 1, wherein, A piping through-hole is formed in the rear floor, through which a pipe extending from the fuel tank passes. The front end of the reinforcement extends to a position that overlaps with the pipe through hole in the front-rear direction of the vehicle body.

4. The rear structure of the vehicle body according to claim 1, wherein, The reinforcement component has: The front and rear extensions extend generally horizontally along the longitudinal direction of the vehicle body; and The inclined portion extends downward from the front end of the front and rear extensions toward the front side of the vehicle body.

5. The rear structure of the vehicle body according to claim 4, wherein, The inclined portion is provided with reinforcing ribs that extend along the direction of the inclined portion.

6. The rear structure of the vehicle body according to claim 1, wherein, The reinforcement is positioned at the end of the tire housing that is outside the vehicle width direction but inside the vehicle width direction.

7. The rear structure of the vehicle body according to claim 1, wherein, The reinforcement component engages with the lower surface of the vehicle chassis at the location where it intersects with the crossbeam.

8. The rear structure of the vehicle body according to claim 7, wherein, At the location where the reinforcement member intersects the closed section along the vehicle width formed by the crossbeam and the vehicle chassis, a partition member is installed to reinforce the closed section from the inside. The outer end of the crossbeam in the vehicle width direction is joined to a reinforcing beam extending upward along the rear wheel arch.

9. The rear structure of the vehicle body according to claim 8, wherein, A fastener bracket for supporting the seat belt fastener is installed on the front side of the vehicle body at the position where it intersects with the reinforcement in the crossbeam.

10. The rear structure of the vehicle body according to claim 1, wherein, A chassis reinforcing rib is formed between the front edge of the tire housing and the rear end of the reinforcing member in the vehicle chassis, extending along the front-rear direction of the vehicle body to the vicinity of the rear end of the reinforcing member.

11. The rear structure of the vehicle body according to claim 10, wherein, A stepped portion is provided at the front edge of the tire storage section, and the upper surface of the stepped portion is higher than the upper surface of the bottom wall of the tire storage section.

12. A rear structure of a vehicle body, wherein, The rear structure of the vehicle body includes: The vehicle chassis has a downwardly recessed tire storage section; and The fuel tank is supported on the lower surface of the vehicle chassis located in front of the tire housing. A reinforcement member is installed at the front position of the tire storage section of the vehicle chassis. This reinforcement member extends along the longitudinal direction of the vehicle body and is used to reinforce the area above the fuel tank of the vehicle chassis. A crossbeam extending along the vehicle width direction is joined at the front position of the tire storage section on the upper surface of the vehicle chassis. The reinforcement component engages with the lower surface of the vehicle chassis at the location where it intersects with the crossbeam. At the location where the reinforcement member intersects the closed section along the vehicle width formed by the crossbeam and the vehicle chassis, a partition member is installed to reinforce the closed section from the inside. The outer end of the crossbeam in the vehicle width direction is joined to a reinforcing beam extending upward along the rear wheel arch. At the front side of the vehicle body, where the crossbeam intersects with the reinforcement, a bracket for supporting the seat belt fastener is installed. The rear end of the reinforcement extends to a position on the rear side of the vehicle body, beyond the rear end of the crossbeam.

13. The rear structure of the vehicle body according to claim 12, wherein, The rear end of the fuel tank extends to a position further rearward than the rear end of the crossbeam on the vehicle body side.

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