Vehicle undercarriage

Abstract

To obtain a vehicle body lower part structure which enables a part of a vehicle to be used continuously while inhibiting entry of water into a passenger compartment.SOLUTION: A vehicle lower part structure includes: rockers 16 each provided at the outer side, in a vehicle width direction, of a vehicle lower part and extending in a vehicle front-rear direction; and a floor panel 38 extending in the vehicle width direction and in the vehicle front-rear direction, forming a floor surface of a passenger compartment, and mechanically fastened by fasteners 50A, 52A in a state that an end in the vehicle width direction overlaps with an upper end 16B of the rocker 16.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a structure in which an end portion of a floor panel is joined to a vertical wall portion of a side sill (rocker) by spot welding. Further, in the structure of Patent Document 1, water tightness inside the vehicle compartment is ensured by applying a sealing agent to a joint portion between the floor panel and the side sill.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, instead of the current economic system, the introduction of a mechanism of circular economy is being considered. However, in a structure in which a floor panel and a rocker are welded as in the structure described in Patent Document 1 above, since the two cannot be separated, it is difficult to continuously use a part of the vehicle.

[0005] An object of the present invention is to obtain a vehicle underbody structure that can continuously use a part of the vehicle while suppressing the intrusion of water into the vehicle compartment.

Means for Solving the Problems

[0006] The vehicle underbody structure according to claim 1 is provided on the outer side in the vehicle width direction of the vehicle underbody and extends in the vehicle longitudinal direction It is composed of an inner wall portion extending in the vehicle vertical direction from the inside in the vehicle width direction, and an upper wall portion extending outward in the vehicle width direction from the upper end of the inner wall portion. a rocker, extending in the vehicle width direction and the vehicle longitudinal direction to form a floor surface of the vehicle compartment, and A general section disposed below the upper end of the inner wall section, a vertical wall section extending upward along the inner wall section from the outer end of the general section in the vehicle width direction, and a section extending outward in the vehicle width direction from the upper end of the vertical wall section in the vehicle vertical direction and overlapping the upper wall section. mechanically fastened by a fastener The inner upper wall covering portion is included and a floor panel, and has.

[0007] In the vehicle understructure according to claim 1, a rocker is provided on the outer side of the underside of the vehicle in the vehicle width direction, and the rocker extends in the vehicle longitudinal direction. The floor panel extends in both the vehicle width direction and the vehicle longitudinal direction to form the floor surface of the passenger compartment. Here, the vehicle width direction end of the floor panel is overlapped with the upper end of the rocker and mechanically fastened together with fasteners. Since the floor panel and the rocker are mechanically fastened together with fasteners in this way, the rocker and the floor panel can be separated by removing the fasteners.

[0008] Furthermore, since the floor panel is fastened to the upper end of the rocker, it can suppress water from entering from the lower side of the vehicle compared to a structure in which the floor panel is fastened to the lower end of the rocker or to an intermediate part in the vertical direction.

[0012] moreover The rocker is composed of an inner wall and an upper wall, and the floor panel is composed of a vertical wall and an inner upper wall covering. In this way, the floor panel has a step along the rocker formed by the vertical wall and the inner upper wall covering, and the inner upper wall covering, which overlaps the upper wall of the rocker, is fastened to the rocker. As a result, compared to a structure in which the floor panel abuts against the inner wall of the rocker, water can be prevented from entering the vehicle interior from below the floor panel without the use of sealant. Consequently, there is no need to remove sealant when separating the rocker and the floor panel.

[0013] Claim 2 The vehicle understructure relating to the claim 1 In this configuration, the lower end of the outer panel constituting the outer body of the vehicle is mechanically fastened to the rocker via a fastener, and the floor panel and the outer panel are joined by welding.

[0014] Claim 2In the vehicle understructure, the outer panel is joined to the floor panel by welding, thus preventing water from entering between the outer panel and the floor panel. Furthermore, since the outer panel is mechanically fastened to the rocker via fasteners, the floor panel and outer panel can be separated from the rocker as a single unit by removing the fasteners.

[0015] Claim 3 The vehicle understructure relating to the claim 2 In this configuration, the floor panel comprises a first flange portion extending upward from the outer end of the inner upper wall covering portion in the vehicle width direction, the outer panel comprises an outer upper wall covering portion fastened to the rocker in a state where it is superimposed on the upper wall portion of the rocker, and a second flange portion extending upward from the inner end of the outer upper wall covering portion in the vehicle width direction, and the first flange portion and the second flange portion are joined by welding in a state where they are superimposed.

[0016] Claim 3 In the vehicle's understructure, the first flange portion formed on the floor panel and the second flange portion formed on the outer panel are joined by welding while overlapping each other. By welding the flange portions together in this way, sufficient welding allowance can be secured without affecting the fastening points using fasteners.

[0017] Claim 4 The vehicle understructure relating to the claim 3 In this configuration, the rocker is configured to include an outer wall portion extending downward from the outer end of the upper wall portion in the vehicle width direction, and the outer panel further comprises an outer wall covering portion extending from the outer upper wall covering portion along the outer wall portion and fastened to the outer wall portion via fasteners.

[0018] Claim 4 In the vehicle understructure relating to this, the outer panel is fastened to the rocker on two surfaces: the upper wall and the outer wall. This allows the outer panel to be firmly fixed to the rocker. Furthermore, the outer wall covering portion of the outer panel covers the outer wall portion of the rocker, ensuring aesthetic appeal.

[0019] The vehicle underbody structure according to claim 5 is such that, in claim 4 the outer panel has a bulging portion that bulges outward in the vehicle width direction, separated from the rocker between the outer upper wall covering portion and the outer wall covering portion.

[0020] In the vehicle underbody structure according to claim 5 since a bulging portion is formed in the outer panel, positioning when fastening the outer panel to the rocker can be easily performed as compared with a structure where there is no gap between the outer panel and the rocker.

[0021] The vehicle underbody structure according to claim 6 is, in claim 1, such that the rocker and the floor panel are fastened at a plurality of locations with a gap in the vehicle longitudinal direction from the front end portion to the rear end portion of the rocker.

[0022] In the vehicle underbody structure according to claim 6 since the floor panel is fastened from the front end portion to the rear end portion of the rocker, the floor panel can be firmly fixed to the rocker.

[0023] The vehicle underbody structure according to claim 7 is, in any one of claims 1 to 6 such that the fastener is composed of a bolt.

[0024] In the vehicle underbody structure according to claim 7 by using a bolt as the fastener, the floor panel and the rocker can be easily separated.

Effect of the Invention

[0025] As described above, according to the vehicle underbody structure of the present invention, while suppressing the intrusion of water into the vehicle interior, a part of the vehicle can be continuously used.

Brief Description of the Drawings

[0026] [Figure 1]This is an exploded perspective view showing the main parts of a vehicle to which the vehicle understructure according to the embodiment is applied. [Figure 2] This is a perspective view of the main part of a vehicle to which the vehicle understructure according to the embodiment is applied, viewed from diagonally below. [Figure 3] This is an enlarged cross-sectional view of the main part, showing the state after cutting along line 3-3 in Figure 2. [Figure 4] This is an enlarged cross-sectional view of the main part of the vehicle understructure of Comparative Example 1, showing an enlarged view of the main part. [Figure 5] This is an enlarged cross-sectional view of the main part of the vehicle understructure of Comparative Example 2. [Modes for carrying out the invention]

[0027] The vehicle understructure according to the embodiment will be described with reference to the drawings. The arrows UP, FR, and LH indicated in each figure as appropriate represent the upper side in the vertical direction of the vehicle, the front side in the longitudinal direction of the vehicle, and the left side of the vehicle when facing the direction of travel, respectively, in the vehicle 10 to which the vehicle understructure is applied. Hereafter, when simply referring to the longitudinal, vertical, and left-right directions, unless otherwise specified, they refer to the longitudinal direction of the vehicle, the vertical direction of the vehicle, and the left-right direction in the vehicle width direction.

[0028] Figure 1 is an exploded perspective view showing the main parts of a vehicle 10 to which the vehicle understructure according to the embodiment is applied. As shown in Figure 1, the vehicle 10 to which the vehicle understructure is applied mainly consists of a lower frame 12 and a shell body 14. The lower frame 12 constitutes the lower skeleton of the vehicle 10 and is equipped with rockers 16 that extend in the longitudinal direction of the vehicle.

[0029] The rockers 16 are located on the outer side of the vehicle's underside in the vehicle's width direction and extend in the vehicle's longitudinal direction, with a pair of rockers 16 provided on both sides in the vehicle's width direction. Each rocker 16 is formed in a closed cross-section by extrusion molding or the like. Details of the rockers 16 will be described later.

[0030] The front ends of a pair of rockers 16 are connected in the vehicle width direction by a dash cross member 18. The rear ends of the front side members 20 are connected to the dash cross member 18. A pair of front side members 20 are provided on both sides in the vehicle width direction, and each extends in the vehicle longitudinal direction. The front side members 20 are formed in a closed cross-section by extrusion molding or the like, but a closed cross-section structure may also be formed by overlapping steel plates.

[0031] The front ends of a pair of front side members 20 are connected in the vehicle width direction by a front cross member 22. Each of the pair of front side members 20 is also provided with a suspension tower 21.

[0032] The rear ends of a pair of rockers 16 are connected in the vehicle width direction by a cross member 19, to which the front ends of rear side members 24 are connected. A pair of rear side members 24 are provided in the vehicle width direction, and each extends in the vehicle longitudinal direction. The rear side members 24 are formed in a closed cross section by extrusion molding or the like, but a closed cross section structure may also be formed by overlapping steel plates. The rear ends of the pair of rear side members 24 are connected in the vehicle width direction by a rear cross member 26.

[0033] The shell body 14 constitutes the passenger compartment (cabin) of the vehicle 10 and mainly consists of a front pillar section 30, a center pillar section 32, a rear pillar section 34, a roof side rail 35, a roof panel 36, a floor panel 38, and an outer panel (side outer panel) 40.

[0034] The front pillar section 30 extends from the front end of the shell body 14 in the vertical direction of the vehicle. The center pillar section 32 extends further to the rear of the vehicle than the front pillar section 30 in the vertical direction of the vehicle. The rear pillar section 34 extends further to the rear of the vehicle than the center pillar section 32 in the vertical direction of the vehicle. Furthermore, the front pillar section 30, the center pillar section 32, and the rear pillar section 34 are provided on both sides in the vehicle width direction and have a closed cross-sectional structure so as to function as the skeleton of the shell body 14.

[0035] The roof side rails 35 connect the upper ends of the front pillar section 30, the center pillar section 32, and the rear pillar section 34 in the longitudinal direction of the vehicle, and are provided on both sides in the vehicle width direction. The roof panel 36 is installed between the left and right roof side rails 35, extends in the vehicle width direction and the vehicle longitudinal direction, and constitutes the ceiling of the passenger compartment.

[0036] The floor panel 38 is located at the bottom of the shell body 14 and extends in the vehicle width direction and the vehicle longitudinal direction, forming the floor surface of the passenger compartment. The floor panel 38 includes a center floor panel connected to the rocker 16 and a rear floor panel connected to the rear side member 24.

[0037] The outer panel 40 constitutes the outer panel of the shell body 14. Specifically, the outer panel 40 is provided on the outer surface of the frame of the front pillar section 30, the outer surface of the frame of the center pillar section 32, and the outer surface of the frame of the rear pillar section 34. The lower part of the outer panel 40 connects the lower ends of the front pillar section 30, the center pillar section 32, and the rear pillar section 34 in the longitudinal direction of the vehicle, and is the part that is fastened to the rocker 16.

[0038] A front opening is formed by the front pillar section 30, the center pillar section 32, the roof side rail 35, and the outer panel 40, and this front opening is closed by a front side door (not shown). Similarly, a rear opening is formed by the center pillar section 32, the rear pillar section 34, the roof side rail 35, and the outer panel 40, and this rear opening is closed by a rear side door (not shown).

[0039] Figure 2 is a perspective view of the main part of the vehicle 10, seen from a diagonal downward angle. As shown in Figure 2, with the shell body 14 assembled to the lower frame 12, the floor panel 38 is fastened to the left and right rockers 16.

[0040] Figure 3 is an enlarged cross-sectional view of the main part, showing the state when cut along line 3-3 in Figure 2. As shown in Figure 3, the rocker 16 has a roughly rectangular outer shape when viewed from the front-rear direction of the vehicle, and is composed of an inner wall portion 16A, an upper wall portion 16B, an outer wall portion 16C, and a lower wall portion 16D. Although only the area around the rocker 16 on the left side of the vehicle is shown in Figure 3, a similar rocker 16 is also provided on the right side of the vehicle.

[0041] The inner wall portion 16A is located on the inside of the rocker 16 in the vehicle width direction and extends in the vehicle vertical direction and the vehicle longitudinal direction. The upper wall portion 16B extends outward in the vehicle width direction from the upper end of the inner wall portion 16A, and the outer wall portion 16C extends downward from the outer end of the upper wall portion 16B in the vehicle width direction. Furthermore, the lower end of the outer wall portion 16C and the lower end of the inner wall portion 16A are connected in the vehicle width direction by the lower wall portion 16D.

[0042] Here, two weld nuts 52A and 52B are provided on the upper wall portion 16B of the rocker 16. Specifically, one weld nut 52A is located inward in the vehicle width direction from the center of the upper wall portion 16B in the vehicle width direction and is fixed to the inner (lower) surface of the upper wall portion 16B. The other weld nut 52B is located outward in the vehicle width direction from the weld nut 52A and is fixed to the inner surface of the upper wall portion 16B.

[0043] A weld nut 52C is provided on the outer wall portion 16C of the rocker 16. The weld nut 52C is located at the lower end of the outer wall portion 16C and is fixed to the inner (right) surface of the outer wall portion 16C. Weld nuts 52A, 52B, and 52C each constitute a fastener of the present invention.

[0044] The floor panel 38 constituting the shell body 14 is composed of a general section 38A, a vertical wall section 38B, and an inner upper wall covering section 38C. The general section 38A extends in the vehicle width direction and the vehicle longitudinal direction, with the plate thickness direction being in the vehicle vertical direction, and constitutes the floor surface of the passenger compartment. The general section 38A is located below the upper end (upper wall section 16B) of the rocker 16.

[0045] A stepped portion is formed at the vehicle width direction end of the general section 38A (floor panel 38), which is bent along the rocker 16. This stepped portion includes a vertical wall portion 38B and an inner upper wall covering portion 38C. The vertical wall portion 38B extends upward from the vehicle width direction outer end of the general section 38A along the inner wall portion 16A of the rocker 16. Specifically, the vertical wall portion 38B is inclined so that it is located outward in the vehicle width direction from the lower end to the upper end. Therefore, the angle between the general section 38A and the vertical wall portion 38B is obtuse.

[0046] The inner upper wall covering portion 38C extends outward in the vehicle width direction from the upper end of the vertical wall portion 38B and is fastened to the rocker 16 in a state where it overlaps with the upper wall portion 16B of the rocker 16. Specifically, the inner upper wall covering portion 38C extends to the central part of the upper wall portion 16B in the vehicle width direction, and an insertion hole is formed at a position corresponding to the weld nut 52A provided on the rocker 16. Then, the inner upper wall covering portion 38C is mechanically fastened to the upper wall portion 16B of the rocker 16 by inserting a bolt 50A from above the inner upper wall covering portion 38C and screwing it into the weld nut 52A.

[0047] A first flange portion 38D extends upward from the outer end in the vehicle width direction of the inner upper wall covering portion 38C, and the first flange portion 38D overlaps with the second flange portion 40C of the outer panel 40, which will be described later.

[0048] The outer panel 40 includes an outer upper wall covering portion 40A that is fastened to the rocker 16 while overlapping the upper wall portion 16B of the rocker 16. The inner end of the outer upper wall covering portion 40A in the vehicle width direction abuts against the inner upper wall covering portion 38C of the floor panel 38, and the outer end of the outer upper wall covering portion 40A in the vehicle width direction extends further outward in the vehicle width direction than the outer wall portion 16C of the rocker 16.

[0049] Here, the outer upper wall covering portion 40A has an insertion hole formed in a position corresponding to the weld nut 52B, and the bolt 50B is inserted from above the outer upper wall covering portion 40A and screwed into the weld nut 52B, thereby mechanically fastening the outer upper wall covering portion 40A to the upper wall portion 16B of the rocker 16.

[0050] Furthermore, a second flange portion 40C extends upward from the inner end of the outer upper wall covering portion 40A in the vehicle width direction, and the first flange portion 38D of the floor panel 38 and the second flange portion 40C of the outer panel 40 are joined together by spot welding or the like in an overlapping state.

[0051] Furthermore, the outer panel 40 includes an outer wall covering portion that extends downward from the outer upper wall covering portion 40A along the outer wall portion 16C of the rocker 16. The outer wall covering portion 40B is fastened to the outer wall portion 16C of the rocker 16 via fasteners. Specifically, the outer wall covering portion 40B has an insertion hole formed at a position corresponding to the weld nut 52C, and the outer wall covering portion 40B is mechanically fastened to the outer wall portion 16C of the rocker 16 by inserting a bolt 50C from the outside of the outer wall covering portion 40B and screwing it into the weld nut 52C.

[0052] Here, the rocker 16 and the floor panel 38 are fastened together at multiple points in the vehicle's longitudinal direction, from the front end to the rear end of the rocker 16. Similarly, the outer panel 40 is fastened to the rocker 16 at multiple points in the vehicle's longitudinal direction, also at intervals in the vehicle's longitudinal direction. That is, multiple bolts 50A, 50B, 50C and weld nuts 52A, 52B, 52C are provided at intervals in the vehicle's longitudinal direction. Bolts 50A, 50B, and 50C each constitute the fasteners of the present invention.

[0053] Furthermore, the outer panel 40 includes a bulging portion 42 that is spaced apart from the rocker 16 and bulges outward in the vehicle width direction between the outer upper wall covering portion 40A and the outer wall covering portion 40B.

[0054] (action) Next, the operation of this embodiment will be explained.

[0055] In the vehicle understructure according to this embodiment, a rocker 16 is provided on the outer side in the vehicle width direction of the underside of the vehicle, and the rocker 16 extends in the vehicle longitudinal direction. The floor panel 38 extends in both the vehicle width direction and the vehicle longitudinal direction to form the floor surface of the passenger compartment. Here, the vehicle width direction end of the floor panel 38 is superimposed on the upper wall portion 16B of the rocker 16 and mechanically fastened with a bolt 50A and a weld nut 52A. Since the floor panel 38 and the rocker 16 are mechanically fastened in this way, the rocker 16 and the floor panel 38 can be easily separated by removing the bolt 50A.

[0056] Furthermore, since the floor panel 38 is fastened to the upper wall portion 16B of the rocker 16, water intrusion from the lower side of the vehicle can be suppressed compared to a structure in which the floor panel 38 is fastened to the lower end or an intermediate portion in the vertical direction of the rocker 16. This effect will be explained in comparison with the structures of Comparative Example 1 and Comparative Example 2.

[0057] (Comparative Example 1) Figure 4 is an enlarged cross-sectional view showing the main parts of the vehicle understructure of Comparative Example 1. As shown in Figure 4, the vehicle 100 according to Comparative Example 1 has a general monocoque structure understructure.

[0058] Specifically, the rocker 102 of the vehicle 100 is composed of a rocker inner panel 106 on the inside in the vehicle width direction and a rocker outer panel 108 on the outside in the vehicle width direction. The rocker inner panel 106 is formed in a roughly hat shape, with a cross section that opens outwards in the vehicle width direction when viewed from the front-rear direction of the vehicle, and an upper flange portion 106A extending in the vehicle vertical direction is formed at the upper end of the rocker inner panel 106. In addition, a lower flange portion 106B extending in the vehicle vertical direction is formed at the lower end of the rocker inner panel 106.

[0059] The rocker outer panel 108 is formed in a roughly hat shape, with its cross-section, viewed from the front-rear direction of the vehicle, opening inward in the vehicle width direction. An upper flange portion 108A extending in the vehicle vertical direction is formed at the upper end of the rocker outer panel 108. The upper flange portion 108A is superimposed on the upper flange portion 106A of the rocker inner panel 106.

[0060] A lower flange portion 108B is formed at the lower end of the rocker outer panel 108, extending in the vertical direction of the vehicle. The lower flange portion 108B is joined to the lower flange portion 106B of the rocker inner panel 106 by spot welding or the like, while overlapping with it.

[0061] The outer panel 110 covers the rocker 102 from the outside in the vehicle width direction, and the upper flange portion 110A at the upper end of the outer panel 110 is joined to the upper flange portion 106A of the rocker inner panel 106 and the upper flange portion 108A of the rocker outer panel 108 by spot welding or the like.

[0062] The lower flange portion 110B is joined to the side of the rocker outer panel 108 by spot welding or the like at the lower end of the outer panel 110.

[0063] The floor panel 104 is composed of a general section 104A and a flange section 104B. The general section 104A is located below the upper end of the rocker 102 and extends in the vehicle width direction and the vehicle longitudinal direction. The flange section 104B extends upward along the rocker 102 from the vehicle width end of the general section 104A and is joined to the side wall of the rocker inner panel 106 by spot welding or the like, overlapping with it. Furthermore, a sealant 112 is applied to the joint between the floor panel 104 and the rocker 102 to ensure watertightness.

[0064] In Comparative Example 1, which is configured as described above, the floor panel 104 and the rocker 102 are welded together, making it difficult to easily separate them. Furthermore, in order to separate the floor panel 104 and the rocker 102, it is necessary to remove the sealant 112. On the other hand, if the sealant 112 is not applied, water may seep in from between the floor panel 104 and the rocker 102. Therefore, in a structure where the floor panel 104 abuts against the side of the rocker 102, the sealant 112 is necessary.

[0065] In contrast, in the vehicle 10 equipped with the vehicle understructure according to this embodiment, as shown in Figure 3, the vehicle width-direction end of the floor panel 38 is mechanically fastened to the upper wall portion 16B of the rocker 16 with bolts 50A and weld nuts 52A while overlapping. This prevents water intrusion without the use of sealing material. In other words, with the vehicle understructure according to this embodiment, a part of the vehicle 10 can be used continuously while preventing water from entering the passenger compartment.

[0066] (Comparative Example 2) Figure 5 is an enlarged cross-sectional view showing the main parts of the vehicle understructure of Comparative Example 2. As shown in Figure 5, the vehicle 200 according to Comparative Example 2 has a ladder frame structure understructure.

[0067] Specifically, the rocker 202 of the vehicle 200 is composed of a rocker inner panel 206 on the inside in the vehicle width direction and a rocker outer panel 208 on the outside in the vehicle width direction. The rocker inner panel 206 is formed in a roughly hat shape, with a cross section viewed from the front-rear direction of the vehicle opening outwards in the vehicle width direction. An upper flange portion 206A extending in the vehicle vertical direction is formed at the upper end of the rocker inner panel 206. A lower flange portion 206B extending in the vehicle vertical direction is formed at the lower end of the rocker inner panel 206.

[0068] The rocker outer panel 208 is formed in a roughly hat shape, with its cross-section, viewed from the front-rear direction of the vehicle, opening inward in the vehicle width direction. An upper flange portion 208A is formed at the upper end of the rocker outer panel 208, extending in the vehicle vertical direction. The upper flange portion 208A is superimposed on the upper flange portion 206A of the rocker inner panel 206.

[0069] A lower flange portion 208B is formed at the lower end of the rocker outer panel 208, extending in the vertical direction of the vehicle. The lower flange portion 208B is joined to the lower flange portion 206B of the rocker inner panel 206 by spot welding or the like, while overlapping with it.

[0070] The outer panel 210 covers the rocker 202 from the outside in the vehicle width direction, and the upper flange portion 210A at the upper end of the outer panel 210 is joined to the upper flange portion 206A of the rocker inner panel 206 and the upper flange portion 208A of the rocker outer panel 208 by spot welding or the like.

[0071] The lower flange portion 210B is joined to the side of the rocker outer panel 208 by spot welding or the like at the lower end of the outer panel 210.

[0072] The floor panel 204 is composed of a general section 204A and a flange section 204B. The general section 204A is located below the upper end of the rocker 202 and extends in the vehicle width direction and the vehicle longitudinal direction. The flange section 204B extends upward along the rocker 202 from the vehicle width direction end of the general section 204A and is joined to the side wall of the rocker inner panel 206 by spot welding or the like, overlapping with it. Furthermore, a reinforcing frame 205 is provided on the lower surface of the vehicle width direction end of the floor panel 204.

[0073] The vehicle body, including the rocker 204, floor panel 204, and outer panel 210 configured as described above, is mounted on the frame 212. Specifically, the side frame 212 is positioned below the floor panel 204, and the side frame 212 extends in the longitudinal direction of the vehicle.

[0074] A pair of side frames 212 are provided on the left and right sides, and multiple cross members (not shown) are installed between the left and right side frames 212, forming a ladder-like frame.

[0075] Mount brackets 214 are fixed to the outer side of the side frame 212 in the vehicle width direction, and the floor panel 204 and reinforcing frame 205 are supported on the mount brackets 214 via body mounts 216.

[0076] Thus, in the ladder frame structure vehicle 200, the body, including the rocker 204, floor panel 204, and outer panel 210, is mounted on the frame 212. Therefore, the frame 212 and rocker 202 form the skeleton, increasing weight and cost compared to the monocoque structure as in this embodiment. Furthermore, in the vehicle 200 of Comparative Example 2, it is necessary to separate the body, including the rocker 204, from the frame 212.

[0077] In contrast, in the vehicle 10 equipped with the vehicle understructure according to this embodiment, the shell body 14 is assembled to the lower frame 12, so it functions as a monocoque structure and does not require a separate frame.

[0078] Furthermore, in the vehicle 10 of this embodiment, by separating the lower frame 12 and the shell body 14, it becomes possible to replace only the shell body 14 without the rocker 16, thereby reducing the cost required for replacement.

[0079] In particular, in the vehicle understructure according to this embodiment, as shown in Figure 3, the rocker 16 is composed of an inner wall portion 16A and an upper wall portion 16B, and the floor panel 38 is composed of a vertical wall portion 38B and an inner upper wall covering portion 38C. Thus, a step is formed in the floor panel 38 along the rocker 16 by the vertical wall portion 38B and the inner upper wall covering portion 38C, and the inner upper wall covering portion 38C, which is superimposed on the upper wall portion 16B of the rocker 16, is fastened to the rocker 16. As a result, compared to a structure in which the floor panel 38 abuts against the inner wall portion 16A of the rocker 16, water can be prevented from entering the vehicle interior from below the floor panel 38 without the use of a sealing material. Consequently, there is no need to remove the sealing material when separating the rocker 16 and the floor panel 38.

[0080] Furthermore, in this embodiment, since the outer panel 40 is joined to the floor panel 38 by welding, water intrusion between the outer panel 40 and the floor panel 38 can be suppressed. Also, since the outer panel 40 is mechanically fastened to the rocker 16 via bolts 50B, 50C and weld nuts 52B, 52C, the floor panel 38 and the outer panel 40 can be separated from the rocker 16 as a single unit by removing these fasteners.

[0081] Furthermore, in this embodiment, the first flange portion 38D formed on the floor panel 38 and the second flange portion 40C formed on the outer panel 40 are joined by welding while overlapping each other. By welding the flange portions together in this way, a sufficient welding allowance can be secured without affecting the fastening points by the fasteners.

[0082] Furthermore, in this embodiment, since the outer panel 40 is fastened to the upper wall portion 16B and the outer wall portion 16C of the rocker 16, the outer panel 40 can be firmly fixed to the rocker 16. In addition, the outer wall covering portion 40B of the outer panel 40 covers the outer wall portion 16C of the rocker 16, thus ensuring aesthetic appeal.

[0083] Furthermore, in this embodiment, since a bulge 42 is formed on the outer panel 40, positioning the outer panel 40 when fastening it to the rocker 16 can be made easier compared to a structure in which there is no gap between the outer panel 40 and the rocker 16.

[0084] In particular, since the floor panel 38 is fastened from the front end to the rear end of the rocker 16, the floor panel 38 can be firmly fixed to the rocker 16.

[0085] Although the vehicle understructure according to the embodiment has been described above, it goes without saying that it can be implemented in various forms without departing from the gist of the present invention. In the above embodiment, the first flange portion 38D of the floor panel 38 and the second flange portion 40C of the outer panel 40 are extended in the vertical direction of the vehicle, but the invention is not limited to this. For example, the first flange portion 38D may be extended in the vehicle width direction along the upper wall portion 16B of the rocker 16, and the second flange portion 40C of the outer panel 40 may be overlapped and welded to the upper surface of the first flange portion 38D. In this case, since the overlapping direction is the vertical direction of the vehicle, a step is formed between the outer upper wall covering portion 40A of the outer panel 40 and the second flange portion 40C. In other words, since the first flange portion 38D is welded in a state where it is inserted between the outer panel 40 and the rocker 16, water intrusion can be suppressed.

[0086] Furthermore, in the above embodiment, the rocker 16 is formed in a closed cross-section without a flange by extrusion molding or the like, but is not limited to this. For example, the rocker may be constructed by welding the flanges of two rigid plates, a rocker inner panel and a rocker outer panel, together. In this case, the first flange portion 38D of the floor panel 38 and the second flange portion 40C of the outer panel 40 may be overlapped and welded so that they extend above the flange portion of the rocker. Alternatively, the first flange portion 38D and the second flange portion 40C may be mechanically fastened to the flange portion of the rocker with bolts and nuts or the like. In any case, the floor panel 38 and the outer panel 40 can be easily separated from the rocker.

[0087] Furthermore, although bolts and weld nuts were used as fasteners in the above embodiment, the invention is not limited to these, and other fasteners may be used. For example, rivets or other fasteners may be used in at least some of the fastening parts. [Explanation of symbols]

[0088] 16 Rocka 16A Inner wall 16B Upper wall 16C Exterior wall 38 Floor Panels 38A General section 38B Vertical wall section 38C Inner upper wall covering 40 Outer Panels 50A, 50B, 50C Bolts (Fasteners) 52A, 52B, 52C Weld Nuts (Fasteners)

Claims

1. A rocker comprising an inner wall portion provided on the outer side in the vehicle width direction at the bottom of the vehicle and extending in the vehicle longitudinal direction, and an inner wall portion extending in the vehicle vertical direction on the inner side in the vehicle width direction, and an upper wall portion extending outward in the vehicle width direction from the upper end of the inner wall portion, A floor panel comprising: a general section extending in the vehicle width direction and the vehicle longitudinal direction to form the floor surface of the passenger compartment and disposed below the upper end of the inner wall section; a vertical wall section extending upward from the outer end of the general section in the vehicle width direction along the inner wall section; and an inner upper wall covering section extending outward in the vehicle width direction from the upper end of the vertical wall section in the vehicle vertical direction and overlapping with the upper wall section, and mechanically fastened with fasteners; A vehicle understructure having the following characteristics.

2. The lower end of the outer panel that constitutes the outer body of the vehicle is mechanically fastened to the rocker via a fastener. The vehicle understructure according to claim 1, wherein the floor panel and the outer panel are joined by welding.

3. The floor panel comprises a first flange portion extending upward from the outer end of the inner upper wall covering portion in the vehicle width direction, The outer panel comprises an outer upper wall covering portion that is fastened to the rocker while overlapping the upper wall portion of the rocker, and a second flange portion that extends upward from the inner end of the outer upper wall covering portion in the vehicle width direction toward the vehicle. The vehicle understructure according to claim 2, wherein the first flange portion and the second flange portion are joined by welding while overlapping each other.

4. The rocker is configured to include an outer wall portion extending downward from the outer end of the upper wall portion in the vehicle width direction, The vehicle understructure according to claim 3, wherein the outer panel further comprises an outer wall covering portion that extends from the outer upper wall covering portion along the outer wall portion and is fastened to the outer wall portion via fasteners.

5. The vehicle understructure according to claim 4, wherein the outer panel has a bulging portion that is spaced apart from the rocker and bulges outward in the vehicle width direction between the outer upper wall covering portion and the outer wall covering portion.

6. The vehicle understructure according to claim 1, wherein the rocker and the floor panel are fastened together at multiple locations at intervals in the longitudinal direction of the vehicle, from the front end to the rear end of the rocker.

7. The vehicle understructure according to any one of claims 1 to 6, wherein the fastener includes a bolt.

Images