Vehicle lower structure

Abstract

To provide a vehicle lower structure which can protect a floor part even when an obstacle, such as a pole, collides with a vehicle from the side.SOLUTION: A frame member 11 is formed by integrally forming a plurality of first portions 110, a plurality of second portions 111, and a pair of third portions 112. The first portions 110 are formed so as to be spaced apart from each other in a front-rear direction and extend in a vehicle width direction. The pair of third portions 112 are arranged along a pair of side sills 10. Each of the second portions 111 is connected to the first portion 110 at the inner side in the vehicle width direction, extends obliquely so as to intersect with the front-rear direction and the vehicle width direction, and is connected to the side sill 10 through the third portion 112 at the outer side in the vehicle width direction. The second portions 111 are provided so that a total length (6×L111) of end portions on the outer side in the vehicle width direction is longer than a total length (3×L110) in the front-rear direction of the first portions 110.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a vehicle undercarriage, and more particularly to a undercarriage in a floor portion. [Background technology]

[0002] 9, a vehicle according to the prior art includes a pair of side sills 910 arranged on both sides of a floor portion in the vehicle width direction, each extending in the front-to-rear direction, and multiple cross members 911 each extending in the vehicle width direction so as to connect the pair of side sills 910. In such a vehicle, when a load F9 is input from the side between the connection points of the side sills 910 and the cross members 911 in the front-to-rear direction, part of the load F9 is split in the longitudinal direction of the side sill 910 (load F91), and part of the load F91 is input to the cross member 911 from the connection points.

[0003] Patent Document 1 discloses a configuration in which a bulkhead is disposed inside a side sill 910 in order to improve the load absorption performance during a side collision. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-91341 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a vehicle according to the prior art, multiple cross members 911, each extending in the vehicle width direction and arranged at regular intervals in the front-to-rear direction, are connected to a pair of left and right side sills 910, and it is thought that the input load F9 during a side collision cannot be sufficiently transmitted to the cross members 911. Therefore, in a vehicle according to the prior art, depending on the location where the side collision load is input to the side sill 910, the input load is difficult to distribute to the opposite side in the vehicle width direction from the input side, and there is a concern that the floor portion cannot be sufficiently protected during a side collision.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a vehicle undercarriage structure that can adequately protect the floor portion even in the event of a side collision with an obstacle such as a pole. [Means for solving the problem]

[0007] A vehicle understructure according to one aspect of the present invention is a understructure for a floor portion of a vehicle, and includes a pair of side sills and a frame member. The pair of side sills are disposed on both sides of the floor portion in the vehicle width direction and are formed so as to extend in the front-rear direction. The frame member is disposed between the pair of side sills.

[0008] The framework member has a plurality of first portions, a plurality of second portions, and a pair of third portions. The plurality of first portions are arranged at intervals in the front-rear direction in a vehicle width direction central portion of the floor portion, and are each formed to extend in the vehicle width direction. The plurality of second portions are each connected to an end of the first portion, each formed to extend outward in the vehicle width direction, and are arranged in the front-rear direction. The pair of third portions are each connected to the plurality of second portions on the vehicle width direction outer sides, each formed to extend in the front-rear direction along the side sill, and are connected to the side sill.

[0009] In the vehicle undercarriage structure of this embodiment, the multiple second portions are formed so that the total length in the fore-and-aft direction of the ends on both outer sides in the vehicle width direction is longer than the total length in the fore-and-aft direction of the multiple first portions.

[0010] In the vehicle understructure according to the above aspect, a frame member having a plurality of first portions and a plurality of second portions is disposed between a pair of side sills. The plurality of second portions are formed so that the total length in the front-rear direction of their ends on both outer sides in the vehicle width direction is longer than the total length in the front-rear direction of the plurality of first portions. Therefore, compared to the conventional technology in which the ends of the cross member are directly fixed to the side sills, even if a side impact load is input to the side sill from a location within a wider range than the conventional technology, the side impact load is transmitted to the first portion via the second portions with high efficiency.

[0011] That is, in the vehicle understructure according to the above aspect, the cross member is not fixed directly to the side sill as in the conventional technology shown in Figure 9, but the second portion is connected to the side sill over a wider area in the longitudinal direction than the first portion. Therefore, even if a side impact load is input to the side sill from a location within a wider range than in the conventional technology, the input load is transmitted to the first portion via the second portion and dispersed to the second portion on the opposite side from the input side. Therefore, the vehicle understructure according to the above aspect can adequately protect the floor portion even in the event of a side collision with an obstacle such as a pole.

[0012] In the vehicle undercarriage structure according to the above aspect, the skeletal member may be configured to be connected to the ends of the plurality of second portions on the outer side in the vehicle width direction, and further include a pair of third portions that are formed so as to extend in the fore-and-aft direction along the side sill and are connected to the side sill.

[0013] In the vehicle undercarriage structure according to the above aspect, the skeletal member has a third portion arranged along the side sill between the second portion and the side sill, so that the load input to the side sill during a side collision is efficiently transmitted to the second portion via the third portion.

[0014] In the vehicle undercarriage structure according to the above aspect, a configuration may be employed in which the second portions adjacent to each other in the longitudinal direction are connected to each other at connection points with the third portion.

[0015] In the vehicle understructure according to the above aspect, adjacent second portions in the longitudinal direction are connected to each other at their connection points with the third portion, so that the side impact load input from the side sill to the third portion can be distributed to adjacent second portions in the longitudinal direction. This allows the load to be distributed more efficiently than when adjacent second portions in the longitudinal direction are spaced apart from each other at their connection points with the third portion, which is effective in protecting the floor portion in the event of a side impact.

[0016] In the vehicle underbody structure according to the above aspect, a configuration may be employed in which the pair of third portions are fixed to the pair of side sills, respectively.

[0017] In the vehicle underbody structure according to the above aspect, the third portion is fixed to the side sill, so that the load input to the side sill during a side collision is efficiently transmitted to the third portion.

[0018] In the vehicle undercarriage structure according to the above aspect, at least some of the plurality of first portions and the plurality of second portions may have a pair of side wall portions formed to extend along the vehicle width direction on both the front-rear and rear-direction sides, and a rib formed to connect the pair of side wall portions.

[0019] In the vehicle understructure according to the above aspect, at least some of the first sections and the second sections have ribs connecting the side walls, which achieves both weight reduction and high rigidity against load compared to a case without ribs, thereby providing further effectiveness in protecting the floor section during a side collision while reducing the vehicle weight.

[0020] In the vehicle undercarriage structure according to the above aspect, the plurality of second portions may have portions that extend diagonally forward as they move outward in the vehicle width direction from the connection point with the first portion, and portions that extend diagonally rearward as they move outward in the vehicle width direction from the connection point with the first portion, and the portions that extend diagonally forward and the portions that extend diagonally rearward may be arranged alternately in the fore-and-aft direction.

[0021] In the vehicle understructure according to the above aspect, the portions extending diagonally forward and the portions extending diagonally rearward are arranged alternately in the front-to-rear direction, so that a load input to the side sill during a side collision is transmitted axially to each second portion and also axially to the first portion connected to the second portion. Therefore, in the vehicle understructure according to the above aspect, even if a side collision load is input to the side sill from a location within a wider range than in the prior art, the load can be transmitted axially to the first portion.

[0022] In the vehicle undercarriage structure according to the above aspect, a configuration may be adopted in which the portion extending diagonally forward and the portion extending diagonally backward, which are adjacent in the fore-and-aft direction, are connected to each other at respective connection points with the first portion.

[0023] In the vehicle undercarriage structure according to the above aspect, the portion extending diagonally forward and the portion extending diagonally backward that are adjacent in the fore-and-aft direction are connected to each other at each connection point with the first portion, so that the load transmitted axially through the second portion is transmitted to the first portion with high efficiency.

[0024] In the vehicle substructure relating to the above aspect, the skeletal members may further have a pair of fourth portions each extending in the fore-and-aft direction and arranged to connect the connection points between the plurality of first portions and the plurality of second portions.

[0025] In the vehicle understructure according to the above aspect, the frame member further includes a pair of fourth sections that connect the connection points between the plurality of first sections and the plurality of second sections, so that the load transmitted through the second sections is also distributed to the adjacent first sections by the fourth sections. Thus, the understructure according to the above aspect can more effectively protect the floor section during a side collision.

[0026] In the vehicle undercarriage structure according to the above aspect, each of the plurality of second portions may be configured so that its width in the fore-and-aft direction gradually increases as it moves from the connection point with the first portion toward the outside in the vehicle width direction.

[0027] In the vehicle understructure according to the above aspect, each of the plurality of second portions is formed so that its longitudinal width gradually increases from the connection point with the first portion toward the outer side in the vehicle width direction, so that even if a side impact load is input to the side sill from a location within a wider range than in the prior art, the input load is efficiently transmitted from the third portion to the second portion. Thus, the vehicle understructure according to the above aspect can adequately protect the floor portion in a side impact.

[0028] In the vehicle undercarriage structure according to the above aspect, the framework member may be integrally formed.

[0029] In the vehicle understructure according to the above aspect, the skeletal members are integrally formed, so the number of parts can be reduced compared to when each part is made up of separate parts, and it is possible to reduce manufacturing costs from the standpoint of reducing the number of steps required for parts management during manufacturing and for connecting each part.

[0030] In the vehicle undercarriage structure relating to the above aspect, each of the pair of side sills may have a side sill outer arranged on the outside in the vehicle width direction and a side sill inner arranged on the inside in the vehicle width direction and fixed to the side sill outer, and at least the side sill inner of the side sill outer and side sill inner that constitute the side sill may be formed integrally with the frame member.

[0031] In the vehicle undercarriage structure according to the above aspect, at least the side sill inner of the side sill outer and side sill inner that make up the side sill is integrally formed with the frame member, which reduces the number of parts compared to when the side sill inner is formed as a separate part from the frame member, thereby enabling reductions in manufacturing costs from the perspective of reducing the number of steps required for parts management during manufacturing and for fixing the side sill inner to the frame member. [Effects of the Invention]

[0032] In the vehicle undercarriage structure according to each of the above aspects, the floor portion can be protected even in the event of a side collision with an obstacle such as a pole. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a plan view showing a partial configuration of a vehicle to which an undercarriage structure according to a first embodiment of the present invention is applied. [Figure 2] 4 is a plan view showing ribs provided in a first portion and a second portion of a skeletal member. FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 10 is a cross-sectional view showing the configuration of a rib according to Modification 1. [Figure 5] FIG. 10 is a cross-sectional view showing the configuration of a rib according to Modification 2. [Figure 6] FIG. 4 is a cross-sectional view showing a joining structure of a framework member to a side sill. [Figure 7] FIG. 2 is a schematic diagram showing a load transmission path during a side collision. [Figure 8] FIG. 4 is a plan view showing a partial configuration of a vehicle to which a lower structure according to a second embodiment of the present invention is applied. [Figure 9] FIG. 1 is a plan view showing a vehicle undercarriage according to a conventional technique. DETAILED DESCRIPTION OF THE INVENTION

[0034] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely illustrative of the present invention, and the present invention is not limited to the following embodiments except for the essential configuration.

[0035] In addition, in the figures used in the following explanation, "FR" indicates the front of the vehicle, "RR" indicates the rear of the vehicle, "LH" indicates the left side of the vehicle, "RH" indicates the right side of the vehicle, "UP" indicates the top of the vehicle, and "LO" indicates the bottom of the vehicle.

[0036] [First embodiment] 1. Vehicle 1 Configuration A partial configuration of a vehicle 1 to which an undercarriage according to a first embodiment is applied will be described with reference to Fig. 1. Note that Fig. 1 illustrates only a portion of the undercarriage of the vehicle 1, and does not illustrate the powertrain and the like.

[0037] 1, a vehicle 1 has a powertrain mounting section 1a in the front where a powertrain is mounted, and a floor section 1b behind the powertrain mounting section 1a where passengers sit. A pair of side sills 10 and a frame member 11 are provided on the floor section 1b.

[0038] The pair of side sills 10 are disposed on both sides of the floor portion 1b in the vehicle width direction and are formed so as to extend in the front-to-rear direction. The frame member 11 is disposed between the pair of side sills 10 so as to connect the side sill 10 on the left side of the vehicle with the side sill 10 on the right side of the vehicle.

[0039] The framework member 11 has a plurality of first portions 110, a plurality of second portions 111, a pair of third portions 112, and a pair of fourth portions 113. The plurality of (for example, three) first portions 110 are arranged at intervals from one another in the front-rear direction in the center portion of the floor portion 1b in the vehicle width direction, and are each formed to extend in the vehicle width direction.

[0040] A plurality of (for example, 12) second portions 111 are connected to the first portions 110, and are formed so as to extend outward in the vehicle width direction, and are arranged in the front-rear direction.

[0041] The pair of third portions 112 are connected to the plurality of second portions 111 on the outer side in the vehicle width direction, and are formed so as to extend in the front-rear direction along the side sill 10, and are fixed to the side sill 10.

[0042] The pair of fourth portions 113 each extend in the front-rear direction and are arranged to connect connection points P1, P3, P5, P6, P8, and P10 between the plurality of first portions 110 and the plurality of second portions 111.

[0043] The plurality of first portions 110, the plurality of second portions 111, the pair of third portions 112, and the pair of fourth portions 113 are each an elongated skeletal portion. In this embodiment, the plurality of first portions 110, the plurality of second portions 111, the pair of third portions 112, and the pair of fourth portions 113 are integrally formed. The skeletal member 11 can be formed by, for example, a casting method.

[0044] The second portions 111 include portions 111a that extend diagonally forward as they move outward in the vehicle width direction from connection points P1, P3, P5, P6, P8, and P10 with the first portion 110, and portions 111b that extend diagonally rearward as they move outward in the vehicle width direction from connection points P1, P3, P5, P6, P8, and P10 with the first portion 110. The portions 111a extending diagonally forward and the portions 111b extending diagonally rearward are arranged alternately in the front-to-rear direction.

[0045] In addition, among the multiple second parts 111, the second parts 111 located in the middle in the fore-and-aft direction (second parts 111 excluding the forward-most part 111a and the rearward-most part 111b) are connected to the third part 112 at connection points P2, P4, P7, and P9 such that adjacent second parts 111 in the fore-and-aft direction are connected to each other without any spacing in the fore-and-aft direction.

[0046] Furthermore, the multiple second parts 111 are connected to each other at connection points P1, P3, P5, P6, P8, and P10 with the first part 110 and the fourth part 113, with adjacent second parts 111 in the front-to-rear direction without any spacing between them in the front-to-rear direction.

[0047] 2. Detailed configuration of the first portion 110 and the second portion 111 of the frame member 11 The detailed configuration of the first portion 110 and the second portion 111 of the skeletal member 11 will be described with reference to Fig. 2 to Fig. 5. Fig. 2 is a plan view showing ribs 110R, 111R provided on the first portion 110 and the second portion 111 of the skeletal member 11. Fig. 3 is a cross-sectional view showing a cross section taken along line III-III in Fig. 2, and Figs. 4 and 5 show modified examples.

[0048] 2, at least some of the multiple first portions 110 and multiple second portions 111 in the skeleton member 11 have a pair of side wall portions 110S, 111S and ribs 11OR, 111R. In the present embodiment, as an example, all of the first portions 110 have a pair of side wall portions 110S and a rib 110R, and all of the second portions 111 have a pair of side wall portions 111S and a rib 111R.

[0049] The pair of side walls 110S in the first portion 110 are formed to extend in the vehicle width direction and face each other in the front-to-rear direction. The pair of side walls 111S in the second portion 111 are formed to extend in an oblique direction inclined with respect to the vehicle width direction and the front-to-rear direction and face each other in a direction perpendicular to the extending directions.

[0050] The plurality of ribs 110R in the first portion 110 are formed so as to connect a pair of side wall portions 110S in the first portion 110. The plurality of ribs 111R in the second portion 111 are formed so as to connect a pair of side wall portions 111S in the second portion 111.

[0051] 3, each of the second portions 111 in this embodiment has an intermediate base 111M connecting a pair of side wall portions 111S in the vertical middle portion, and the ribs 111R are provided to rise in the vertical direction from the intermediate base 111M. The side wall surfaces 111W of the pair of side wall portions 111S and the side wall surfaces 111W of the ribs 111R are formed to have a draft angle θ with respect to an imaginary line LN drawn in the vertical direction.

[0052] Although not shown, the plurality of first portions 110 also have the same configuration as that shown in FIG.

[0053] However, each of the plurality of first portions 110 and the plurality of second portions 111 may have the configuration shown in Fig. 4 or Fig. 5. Specifically, as shown in Fig. 4, each of the plurality of second portions 111 in Modification 1 may have a lower base 111L at the bottom that connects a pair of side wall portions 111S, and the rib 111R may be provided to rise upward from the lower base 111L. The plurality of first portions 110 may also have a configuration similar to that shown in Fig. 4.

[0054] 5, each of the second portions 111 in Modification 2 may have an upper base 111U at its upper portion that connects a pair of sidewall portions 111S, and the rib 111R may be provided to hang down from the upper base 111U. Each of the first portions 110 may also have a configuration similar to that shown in FIG.

[0055] 3. Structure for fixing the frame member 11 to the side sill 10 The structure for fixing the framework member 11 to the side sill 10 will be described with reference to Fig. 6. Fig. 6 is a cross-sectional view showing the side sill 10 disposed on the left side and a part of the third portion 112 of the framework member 11.

[0056] As shown in Fig. 6, the side sill 10 of the vehicle 1 according to this embodiment is formed by combining a side sill outer 100 and a side sill inner 101. The side sill outer 100 is a portion disposed on the outer side in the vehicle width direction. The side sill inner 101 is a portion disposed on the inner side in the vehicle width direction.

[0057] The side sill outer 100 and the side sill inner 101 each have a hat-shaped cross section, and their flange portions are fixed to each other to form a side sill 10 having a closed cross section.

[0058] The third portion 112 of the framework member 11 has a flange portion 112f1 formed along part of the upper surface of the side sill inner panel 101, and a flange portion 112f2 formed along part of the inner surface of the side sill inner panel 101.

[0059] The flange portions 112f1 and 112f2 of the third portion 112 are fixed to the side sill inner panel 101 at fixing points JP, respectively. This fixes the framework member 11 to the side sill 10. The method for fixing the third portion 112 to the side sill inner panel 101 is not particularly limited, but may be, for example, fastening using bolts or rivets, or resistance welding or laser welding.

[0060] In this embodiment, the side sill outer 100 and the side sill inner 101 are separate members from the framework member 11, but it is also possible to form at least the side sill inner 101 and the framework member 11 integrally.

[0061] 4. Relationship between the second portion 111 and the first portion 110 The relationship between the second portion 111 and the first portion 110 in the framework member 11 will be described with reference to Fig. 7. Fig. 7 is a plan view of the side sill 10 and the framework member 11 as viewed from above.

[0062] 7, in this embodiment, the first portion 110, the second portion 111, the third portion 112, and the fourth portion 113 each have a long columnar shape. In this embodiment, as an example, the width of each of the portions 110 to 113 is uniform in the longitudinal direction.

[0063] Each of the first portions 110 has a length (width) L110 in the front-rear direction. However, the lengths L110 in the front-rear direction of the multiple first portions 110 may be different from one another.

[0064] The second portions 111 each have a length L111 at their outer ends in the vehicle width direction. However, the lengths L111 in the front-rear direction of the ends of the second portions 111 may be different from one another.

[0065] In this embodiment, the plurality of first portions 110 and the plurality of second portions 111 are formed so as to satisfy the following relationship. 6×L111>3×L110 (Number 1) That is, in this embodiment, the multiple second portions 111 are formed so that the total length in the fore-and-aft direction of the ends on each of the outer sides (left and right) in the vehicle width direction (6 x L111) is longer than the total length in the fore-and-aft direction of the multiple first portions 110 (3 x L110).

[0066] 5. Arrangement of the second portion 111, the third portion 112, and the fourth portion 113 The arrangement of the second portion 111, the third portion 112, and the third portion 113 in the framework member 11 will be described with reference to FIG.

[0067] 7, the third portion 112 and the fourth portion 113 are arranged side by side with a gap in the vehicle width direction. As described above, the second portion 111 has portions 111a extending diagonally forward and portions 111b extending diagonally backward, which are alternately arranged in the front-rear direction.

[0068] When extracting the portion 111a extending diagonally forward and the portion 111b located behind it extending diagonally backward, the skeletal member 11 includes the portion 111a, the portion 111b, and the third portion 112 to form a structural portion (triangular structural portion) AR1 having a triangular shape in a plan view.

[0069] Furthermore, when extracting the portion 11b extending diagonally backward and the portion 111a located behind it extending diagonally forward, the portion 111b, the portion 111a, and the fourth portion 113 in the skeletal member 11 form a structural portion (triangular structural portion) AR2 that is triangular in plan view.

[0070] The triangular structural portions AR1 and AR2 have a triangular hollow portion inside in a plan view, and are portions having a structure similar to a so-called truss structure. However, in the skeletal member 11 of this embodiment, the nodes between the second portion 111 and the third portion 112 and the fourth portion 113 are not fastened with bolts or rivets, but the portions 111 to 113 are integrally connected at each node.

[0071] The frame member 11 of this embodiment has a configuration in which triangular structural portions AR1 and AR2 are alternately arranged in the front-rear direction on both outer sides in the vehicle width direction of a first portion 110 extending in the vehicle width direction.

[0072] 6.Effects In a vehicle 1 to which the undercarriage structure according to this embodiment is applied, a frame member 11 having a plurality of first portions 110 and a plurality of second portions 111 is disposed between a pair of side sills 10. The plurality of second portions 111 are formed so that the total length in the front-rear direction of their ends on both outer sides in the vehicle width direction (6×L111) is longer than the total length in the front-rear direction of the plurality of first portions 110 (3×L110). Therefore, even if a side impact load F0 is input to the side sill 10 from a location within a wider range than in the prior art, the input side impact load F0 is efficiently transmitted to the first portions 110 via the second portions 111 as shown by arrows F1 and F2.

[0073] That is, in the vehicle 1 to which the undercarriage structure according to this embodiment is applied, the cross member 911 is not directly connected to the side sill 910 as in the conventional technology shown in FIG. 9 , but the second portion 111 is connected to the side sill 10 over a region that is wider in the longitudinal direction than the first portion 110. Therefore, even if a side impact load F0 is input to the side sill 10 from a location within a wider range than in the conventional technology, the input side impact load F0 is transmitted to the first portion 110 via the second portion 111 and dispersed to the second portion 111 on the opposite side from the side to which the load was input. Therefore, in the vehicle 1, the floor portion 1b can be sufficiently protected even when an obstacle such as a pole collides with the vehicle 1 from the side.

[0074] Furthermore, in the vehicle 1 to which the undercarriage structure of this embodiment is applied, the skeleton member 11 has a third portion 112 arranged along the side sill 10 between the second portion 111 and the side sill 10, so that the collision load F0 input to the side sill 10 during a side collision is dispersed in both the front and rear directions through the third portion 112 and is efficiently transmitted to the second portion 111.

[0075] Furthermore, in the vehicle 1 to which the undercarriage structure according to this embodiment is applied, adjacent second portions 111 in the longitudinal direction are connected to each other at connection points P2, P4, P7, and P9 with the third portion 112, so that the side impact load input from the side sill 10 to the third portion 112 can be distributed with high efficiency to adjacent second portions 111 in the longitudinal direction. Therefore, the load can be distributed more efficiently than when adjacent second portions 111 in the longitudinal direction are spaced apart from each other at connection points P2, P4, P7, and P9 with the third portion 112, which is effective in protecting the floor portion 1b in the event of a side impact.

[0076] Furthermore, in the vehicle 1 in which the undercarriage structure of this embodiment is adopted, the third portion 112 is fixed to the side sill 10 as shown in FIG. 6, so that the collision load F0 input to the side sill 10 during a side collision is efficiently transmitted to the third portion 112.

[0077] Furthermore, in the vehicle 1 employing the undercarriage structure according to this embodiment, the plurality of first portions 110 and the plurality of second portions 111 each have the ribs 110R, 111R connecting the side wall portions 110S, 111S, so that the vehicle 1 is both lighter in weight and has higher rigidity against collision loads than when the ribs 110R, 111R are not provided. This is therefore more effective in protecting the floor portion 1b during a side collision while reducing the weight of the vehicle 1.

[0078] Furthermore, in a vehicle 1 employing the undercarriage structure according to this embodiment, the second portions 111 have portions 111a extending diagonally forward and portions 111b extending diagonally backward, which are arranged alternately in the front-to-rear direction, so that a side impact load F0 input to the side sill 10 during a side impact is transmitted as an axial force to each second portion 111, and is also transmitted in the axial direction to the first portion 110 connected to the second portions 111. Therefore, the vehicle 1 is able to transmit the load in the axial direction to the first portion 110 even when a side impact load F0 is input to the side sill 10 from a location within a wider range than in the prior art.

[0079] Furthermore, in the vehicle 1 to which the undercarriage structure of this embodiment is applied, the section 111a extending diagonally forward and the section 111b extending diagonally backward, which are adjacent in the fore-and-aft direction, are connected to each other at respective connection points P1, P3, P5, P6, P8, and P10 with the first section 110, so that the load transmitted axially through the second section 111 is transmitted to the first section 110 with high efficiency.

[0080] Furthermore, in the vehicle 1 to which the undercarriage structure according to this embodiment is applied, the frame member 11 further has a pair of fourth portions 113 that connect the connection points P1, P3, P5, P6, P8, and P10 between the plurality of first portions 110 and the plurality of second portions 111, so that the load transmitted through the second portions 111 is also distributed to the first portions 110 adjacent in the fore-and-aft direction by the fourth portions 113. Therefore, the undercarriage structure according to this embodiment can more effectively protect the floor portion 1b during a side collision.

[0081] Furthermore, the vehicle 1 to which the undercarriage structure of this embodiment is applied is formed by integrally forming a plurality of first sections 110, a plurality of second sections 111, a pair of third sections 112, and a pair of fourth sections 113, so the number of parts can be reduced compared to when each section 110 to 113 is made up of separate parts, and it is possible to reduce manufacturing costs from the perspective of parts management during manufacturing.

[0082] As explained above, the vehicle 1 to which the undercarriage structure according to this embodiment is applied can sufficiently protect the floor portion 1b even when it is hit from the side by an obstacle such as a pole.

[0083] [Second embodiment] The configuration of a vehicle to which the undercarriage according to the second embodiment is applied will be described with reference to Fig. 8. Note that the vehicle to which the undercarriage according to this embodiment is applied differs from the first embodiment in the configuration of the framework member 21, but the other configurations are the same. Therefore, the following will describe the configuration of the framework member 21, which is the difference from the first embodiment.

[0084] 8, the framework member 21 of this embodiment has a plurality of (for example, three) first portions 210, a plurality of (for example, six) second portions 211, and a pair of third portions 212. Similar to the plurality of first portions 110 in the first embodiment, the plurality of first portions 210 are arranged at intervals from each other in the front-rear direction in the vehicle width direction central portion of the floor portion 1b, and are each formed to extend in the vehicle width direction.

[0085] Similar to the pair of third portions 112 in the first embodiment, the pair of third portions 212 are each connected to a plurality of second portions 211 on the outer side in the vehicle width direction, and are each formed to extend in the fore-and-aft direction along the side sill 10, and are each fixed to the side sill 10.

[0086] The multiple second portions 211 are each connected to the first portion 210 and are formed in a fan shape such that their front-to-rear width gradually increases from the connection point with the first portion 210 toward the outer side in the vehicle width direction. The multiple second portions 211 are arranged side by side in the front-to-rear direction on each outer side in the vehicle width direction.

[0087] The plurality of first portions 210, the plurality of second portions 211, and the pair of third portions 212 are integrally formed. As in the first embodiment, the framework member 21 can be formed by, for example, casting.

[0088] The second portions 211 are connected to the second portions 212 at connection points P11 to P14 such that adjacent second portions 211 in the front-rear direction are not spaced apart from each other in the front-rear direction.

[0089] In this embodiment, the first portion 210 and the third portion 212 each have a long columnar shape. Also in this embodiment, as an example, the width of the first portion 210 and the third portion 212 is uniform in the longitudinal direction.

[0090] Each of the first portions 210 has a length (width) in the front-rear direction of L210. However, the lengths L210 in the front-rear direction of the multiple first portions 210 may be different from one another.

[0091] The second portions 211 each have a length L211 at their outer ends in the vehicle width direction (the length of the connection with the third portion 212). However, the front-rear direction lengths L211 of the ends of the multiple second portions 211 may be different from one another.

[0092] In this embodiment, the plurality of first portions 210 and the plurality of second portions 211 are formed so as to satisfy the following relationship. 3×L211>3×L210 (equation 2) That is, in this embodiment, too, the multiple second portions 211 are formed so that the total length in the fore-and-aft direction of the ends on both outer sides (left and right) in the vehicle width direction (3 x L211) is longer than the total length in the fore-and-aft direction of the multiple first portions 210 (3 x L210).

[0093] Although the vehicle employing the understructure according to this embodiment has a different structure of the frame member 21 from that of the first embodiment, the frame member 21 is configured to satisfy the above-described relational expression 2, and therefore the same effects as those of the first embodiment can be obtained. That is, in the understructure according to this embodiment, each of the multiple second portions 211 is also formed so that its longitudinal width gradually increases from the connection point with the first portion 210 toward the outer side in the vehicle width direction. Therefore, even if a side impact load is input to the side sill 10 from a location within a wider range than in the prior art, the load is efficiently transmitted from the third portion 212 to the second portion 211. Therefore, the understructure according to this embodiment can also adequately protect the floor portion during a side impact.

[0094] In this embodiment as well, at least some of the plurality of first portions 210 and the plurality of second portions 211 may have a pair of sidewall portions and a rib, similar to the first embodiment.

[0095] [Other variations] In the first embodiment, the skeletal member 11 has the third portion 112 and the fourth portion 113, and in the second embodiment, the skeletal member 21 has the third portion 212. However, in the present invention, it is not essential that the skeletal member have the third portion or the fourth portion. Note that, if the skeletal member does not have the third portion, each of the second portions may be fixed to the side sill.

[0096] Furthermore, in the first and second embodiments, a structure is adopted in which the third portions 112, 212 of the frame members 11, 21 are directly fixed to the side sill 10, but the present invention may also employ a separate member interposed between the third portions and the side sill. Various connection structures can be employed as long as they are configured to transmit the collision load input to the side sill to the frame member.

[0097] In the first embodiment, the second portion 111 of the framework member 11 has the portion 111a extending diagonally forward and the portion 111b extending diagonally backward, but the present invention is not limited to this. For example, the second portion may have only the portion extending diagonally forward or only the portion extending diagonally backward.

[0098] In the second embodiment, the second portion 211 of the framework member 21 has a planar shape formed by combining two trapezoidal portions, but the present invention is not limited to this. For example, the second portion 211 may have a shape in which the length (width) in the front-rear direction increases exponentially or quadratically in plan view.

[0099] In the first embodiment, the first portion 110 and the second portion 111 of the framework member 11 each have sidewalls 110S, 111S and ribs 110R, 111R, but the present invention is not limited to this. Both the first portion and the second portion may have a solid rod shape and may not have ribs. Also, only some of the multiple first portions and multiple second portions may have ribs.

[0100] In the first and second embodiments, the frame members 11 and 21 are integrally formed, but the present invention is not limited to this. For example, the first and second portions may be fastened together with bolts or rivets, or may be welded together.

[0101] Furthermore, the skeletal members do not necessarily have to be made of a metal material, but may be made of, for example, a fiber-reinforced resin material (such as CFRP or GFRP), or may be made of a composite of a resin material (including a fiber-reinforced resin material) and a metal material.

[0102] In the first and second embodiments, no particular mention is made of the vertical size of the frame members 11, 21, but the present invention allows various changes to the vertical size. For example, the vertical size of the frame member may be different for each region in the front-rear direction or the vehicle width direction, or may be different between the first and second regions.

[0103] Although the first and second embodiments did not mention the floor panel, the floor panel can be integrally formed as part of the frame member, or the floor panel can be fixed to the frame member. [Explanation of symbols]

[0104] 1 vehicle 1b Floor section 10 Side sill 11,12 Skeleton members 110,210 Part 1 110R Rib 111,211 2nd part 111R Rib 112,212 3rd part

Claims

1. A lower structure of a floor portion of a vehicle, a pair of side sills disposed on both sides of the floor portion in the vehicle width direction and extending in the front-rear direction; a framework member disposed between the pair of side sills; Equipped with The skeletal member is a plurality of first portions disposed at a vehicle width direction central portion of the floor portion at intervals in the front-rear direction and each formed to extend in the vehicle width direction; a plurality of second sections each connected to an end of the first section, each extending outward in the vehicle width direction, and arranged in the front-rear direction; and The plurality of second portions are formed such that a total length in the front-rear direction of their ends on both outer sides in the vehicle width direction is longer than a total length in the front-rear direction of the plurality of first portions. Vehicle undercarriage.

2. The framework member further includes a pair of third portions connected to the ends of the plurality of second portions on outer sides in the vehicle width direction, extending in the front-rear direction along the side sill, and connected to the side sill. The vehicle undercarriage according to claim 1 .

3. The second portions adjacent to each other in the front-rear direction are connected to each other at connection points with the third portion. The vehicle undercarriage according to claim 2.

4. The pair of third portions are fixed to the pair of side sills, respectively. The vehicle undercarriage according to claim 2.

5. At least some of the plurality of first regions and the plurality of second regions have a pair of side wall portions formed so as to extend along the vehicle width direction on both sides in the front-rear direction, and a rib formed so as to connect the pair of side wall portions. The vehicle undercarriage according to claim 1 .

6. the plurality of second portions include portions that extend obliquely forward as they move outward in the vehicle width direction from the connection points with the first portions, and portions that extend obliquely rearward as they move outward in the vehicle width direction from the connection points with the first portions, The portions extending diagonally forward and the portions extending diagonally backward are alternately arranged in the front-rear direction.

6. The vehicle underbody structure according to claim 1.

7. The portion extending diagonally forward and the portion extending diagonally rearward that are adjacent in the front-rear direction are connected to each other at connection points with the first portion.

7. The vehicle undercarriage according to claim 6.

8. the skeletal member further includes a pair of fourth portions each extending in the front-rear direction and arranged to connect connection points between the plurality of first portions and the plurality of second portions; 6. The vehicle underbody structure according to claim 1.

9. Each of the plurality of second portions is formed so that its width in the front-rear direction gradually increases from a connection point with the first portion toward an outer side in the vehicle width direction.

6. The vehicle underbody structure according to claim 1.

10. The skeletal member is integrally formed.

6. The vehicle underbody structure according to claim 1.

11. Each of the pair of side sills has a side sill outer disposed on an outer side in the vehicle width direction and a side sill inner disposed on an inner side in the vehicle width direction and fixed to the side sill outer, At least the side sill inner of the side sill outer and the side sill inner that constitute the side sill is integrally formed with the frame member. The vehicle undercarriage according to claim 1 .

Images