Lower structure of vehicle

Abstract

The present invention provides a lower structure of a vehicle capable of protecting a floor part even when an obstacle such as a pillar collides from the side. In the skeleton member (11), a plurality of first portions (110), a plurality of second portions (111), and a pair of third portions (112) are integrally formed. The plurality of first portions (110) are spaced apart from each other in the front-rear direction and each extend in the vehicle width direction. The paired third portions (112) are disposed along the paired side members (10). Each of the plurality of second portions (111) is connected to the first portion (110) on the inner side in the vehicle width direction, extends in an oblique direction so as to intersect both in the front-rear direction and the vehicle width direction, and is connected to the side member (10) on the outer side in the vehicle width direction via a third portion (112). The total length (6 * L111) of the ends of the plurality of second portions (111) on the outer side in the vehicle width direction is longer than the total length (3 * L110) of the plurality of first portions (110) in the front-rear direction.

Description

Technical Field

[0001] This invention relates to a lower structure of a vehicle, and more particularly to a lower structure in a floor section. Background Technology

[0002] like Figure 9 As shown, the vehicle in the prior art includes: a pair of side beams 910 disposed on both sides of the floor in the vehicle width direction and extending in the longitudinal direction, and a plurality of crossbeams 911 extending in the vehicle width direction and connecting the pairs of side beams 910. In such a vehicle, when a load F9 from the side is input between the joints of the side beams 910 and the crossbeams 911 in the longitudinal direction, a portion of the load F9 is distributed in the longitudinal direction of the side beams 910 (load F91), and a portion of the load F91 is input to the crossbeams 911 from the joint.

[0003] Patent document 1 discloses a structure in which a partition is arranged inside the side beam 910 in order to improve the load absorption performance during a side collision.

[0004] [Existing Technical Documents] [Patent Documents] [Patent Document 1] Japanese Patent Application Publication No. 2021-91341. Summary of the Invention

[0005] [The technical problem the invention aims to solve] However, in the vehicles involved in the prior art, a plurality of crossbeams 911, arranged at certain intervals in the longitudinal direction and extending in the vehicle width direction, are connected to paired side beams 910. Therefore, it is considered that the input load F9 during a side collision cannot be adequately transferred to the crossbeams 911. Consequently, in the vehicles involved in the prior art, depending on the input location of the side collision load to the side beams 910, the input load is difficult to distribute to the opposite side in the vehicle width direction from the input side, raising concerns that the floor may not be adequately protected during a side collision.

[0006] The present invention aims to solve the above-mentioned problems and its purpose is to provide a vehicle substructure that can adequately protect the floor when an obstacle such as a pillar collides from the side.

[0007] Technical means to solve technical problems One aspect of the present invention relates to a vehicle lower structure, which is a floor substructure of a vehicle and includes a pair of side beams and a frame member. The pair of side beams are disposed on both sides of the floor in the vehicle width direction and are formed to extend in the longitudinal direction, respectively. The frame member is disposed between the pair of side beams.

[0008] The frame member has a plurality of first portions, a plurality of second portions, and a pair of third portions. The plurality of first portions are spaced apart from each other in the longitudinal direction at the central portion of the floor section in the vehicle width direction, and are formed to extend in the vehicle width direction. The plurality of second portions are connected to the ends of the first portions, and are formed to extend outward in the vehicle width direction, and are arranged in the longitudinal direction. The pair of third portions are connected to the plurality of second portions on their outer sides in the vehicle width direction, and are formed to extend along the side beams in the longitudinal direction, and are connected to the side beams.

[0009] In the lower structure of the vehicle involved in this embodiment, the plurality of second parts are formed such that the total length of the ends on both outer sides in the vehicle width direction in the front-rear direction is longer than the total length of the plurality of first parts in the front-rear direction.

[0010] In the lower structure of the vehicle described above, a skeleton member having a plurality of first parts and a plurality of second parts is disposed between pairs of side beams. The combined length of the ends of the plurality of second parts on both outer sides in the vehicle width direction in the longitudinal direction is longer than the combined length of the plurality of first parts in the longitudinal direction. Therefore, compared with the prior art where the ends of the crossbeams are directly fixed to the side beams, even when a lateral collision load is input to the side beam from a location with a wider range than that in the prior art, the lateral collision load can be efficiently transferred from the second parts to the first parts.

[0011] That is, in the lower structure of the vehicle involved in the above-mentioned form, it is not like... Figure 9 Unlike the prior art where the crossbeam is directly fixed to the side beam, the second part connects to the side beam over a wider area in the longitudinal direction compared to the first part. Therefore, even when a lateral collision load is input to the side beam from a location with a wider range than that described in the prior art, the input load is transferred to the first part via the second part and dispersed to the second part on the opposite side of the input side. Thus, in the lower structure of the vehicle described above, the floor is adequately protected even in the event of a side collision with obstacles such as pillars.

[0012] In the lower structure of the vehicle described above, the following structure may also be adopted: the frame member further has a pair of third parts, the pair of third parts being connected to the ends of the plurality of second parts on the outer side in the vehicle width direction, and being formed to extend along the side beam in the front-rear direction and connected to the side beam.

[0013] In the lower structure of the vehicle described above, the frame member has a third part along the side beam and disposed between the second part and the side beam. Therefore, in the event of a lateral collision, the load input to the side beam is efficiently transferred to the second part through the third part.

[0014] In the lower structure of the vehicle described above, the following structure may also be adopted: each of the second parts adjacent in the front-rear direction is connected to the third part at each connection point.

[0015] In the lower structure of the vehicle described above, adjacent second parts in the longitudinal direction are interconnected at their respective connections with the third part. Therefore, lateral impact loads input from the side beams to the third part can be dispersed to the adjacent second parts in the longitudinal direction. Thus, compared to when adjacent second parts in the longitudinal direction are separated at their connections with the third part, the load can be dispersed more efficiently, which is effective in protecting the floor during a lateral collision.

[0016] In the lower structure of the vehicle described above, the following structure can also be adopted: the paired third parts are respectively fixed to the paired side beams.

[0017] In the lower structure of the vehicle described above, the third part is fixed to the side beam. Therefore, during a lateral collision, the load input to the side beam is efficiently transferred to the third part.

[0018] In the lower structure of the vehicle described above, the following structure may also be adopted: at least a portion of the plurality of first parts and the plurality of second parts have: a pair of sidewalls extending in the vehicle width direction on both sides in the front-rear direction, and ribs connecting the pairs of sidewalls.

[0019] In the lower structure of the vehicle described above, at least a portion of the plurality of first parts and the plurality of second parts have ribs connecting the side walls, thus achieving both lightweighting and high rigidity relative to load compared to the absence of ribs. Therefore, it is more effective in achieving vehicle lightweighting and protecting the floor in side collisions.

[0020] In the lower structure of the vehicle described above, the following structure may also be adopted: the plurality of second parts have: a part that extends diagonally forward and outward in the vehicle width direction from the connection point with the first part, and a part that extends diagonally backward and outward in the vehicle width direction from the connection point with the first part, and the diagonally forward and diagonally backward parts are alternately arranged in the front-rear direction.

[0021] In the lower structure of the vehicle described above, the portions extending diagonally forward and diagonally backward are alternately arranged in the longitudinal direction. Therefore, during a side collision, the load input to the side beam is transmitted in the axial direction at each of the second portions, and the load is also transmitted in the axial direction at the first portion connected to the second portions. Thus, in the lower structure of the vehicle described above, even when a side collision load is input to the side beam from a portion with a wider range than that in the prior art, the load can still be transmitted to the first portion in the axial direction.

[0022] In the lower structure of the vehicle described above, the following structure may also be adopted: the adjacent forward-extending portions and the backward-extending portions are connected to each other at their respective connection points with the first portion.

[0023] In the lower structure of the vehicle described above, the adjacent parts extending diagonally forward and diagonally backward in the longitudinal direction are connected to each other at the connection points of the first part. Therefore, the load transmitted in the axial direction in the second part is efficiently transmitted to the first part.

[0024] In the lower structure of the vehicle described above, the following structure may also be adopted: the frame member further has a pair of fourth parts, the pair of fourth parts extending in the front-rear direction respectively, and configured as connection points connecting the plurality of first parts and the plurality of second parts.

[0025] In the lower structure of the vehicle described above, the frame member also has paired fourth portions connecting the joints of the plurality of first portions and the plurality of second portions. Therefore, the load transmitted in the second portion is also distributed to the adjacent first portion through the fourth portion. Thus, in the lower structure described above, the floor portion can be protected more effectively in a side collision.

[0026] In the lower structure of the vehicle described above, the following structure can also be adopted: the plurality of second parts gradually increase in width in the front-rear direction from the connection point with the first part outward in the vehicle width direction.

[0027] In the lower structure of the vehicle described above, the plurality of second portions gradually increase in width in the longitudinal direction from their connection points with the first portion outwards. Therefore, even when a lateral collision load is input to the side beam from a portion covering a wider range than that described in the prior art, the input load is efficiently transferred from the third portion to the second portion. Thus, in the lower structure of the vehicle described above, adequate protection of the floor during a lateral collision can be achieved.

[0028] In the lower structure of the vehicle described above, the following structure can also be adopted: the frame component is integrally formed.

[0029] In the lower structure of the vehicle described above, the frame components are formed as a single unit. Therefore, compared with each part being composed of separate components, the number of parts can be reduced. From the viewpoint of reducing the time spent on component management and the time spent on connecting the parts during manufacturing, manufacturing costs can be reduced.

[0030] In the lower structure of the vehicle described above, the following structure may also be adopted: the paired side beams each have: an outer beam disposed on the outer side in the vehicle width direction and an inner beam disposed on the inner side in the vehicle width direction and fixed to the outer beam, wherein at least the inner beam within the outer beam and the inner beam constituting the side beam is integrally formed with the frame member.

[0031] In the lower structure of the vehicle described above, at least the inner beam within the outer and inner side beams that constitute the side beams is integrally formed with the frame members. Therefore, compared to when the inner side beams and frame members are composed of different components, the number of parts can be reduced. Thus, from the viewpoint of reducing the time spent on component management during manufacturing and reducing the time spent on fixing the frame members and inner side beams, manufacturing costs can be reduced.

[0032] [Invention Effects] In the lower structure of the vehicles involved in the above-mentioned forms, the floor can be protected even when an obstacle such as a pillar collides from the side. Attached Figure Description

[0033] Figure 1 This is a top view of a portion of the structure of a vehicle to which the lower structure according to the first embodiment of the present invention is applied; Figure 2 This is a top view of the rib arches present in the first and second parts of the skeleton component; Figure 3 for Figure 2 Cross-sectional view of line III-III; Figure 4 This is a cross-sectional view of the ribbed arch structure involved in variation example 1; Figure 5 This is a cross-sectional view of the ribbed arch structure involved in variation example 2; Figure 6 This is a cross-sectional view of the joint structure between the skeleton members and the side beams; Figure 7 This is a schematic diagram of the load transfer path during a lateral collision; Figure 8 This is a top view of a portion of the structure of a vehicle to which the lower structure according to the second embodiment of the present invention is applied; Figure 9 This is a top view of the lower structure of a vehicle as described in the prior art. Detailed Implementation

[0034] Embodiments of the present invention will now be described with reference to the accompanying drawings. The embodiments described below are merely illustrative of the invention, and the invention is not limited in any way except for its essential structure.

[0035] In the diagrams used below, "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. Structure of Vehicle 1 use Figure 1 This describes a portion of the structure of vehicle 1 that incorporates the lower structure described in the first embodiment. Figure 1 In this illustration, only a portion of the lower structure of vehicle 1 is shown; the powertrain and other components are omitted.

[0037] like Figure 1 As shown, vehicle 1 has a powertrain mounting section 1a at the front, which houses the powertrain, and a passenger seating area, namely floor section 1b, at the rear relative to the powertrain mounting section 1a. A pair of side beams 10 and frame members 11 are provided in the floor section 1b.

[0038] A pair of side beams 10 are disposed on both sides of the floor portion 1b in the vehicle width direction and extend in the front-rear direction respectively. The frame member 11 is disposed between the pair of side beams 10 in a manner that connects the side beam 10 on the left side of the vehicle and the side beam 10 on the right side of the vehicle.

[0039] The frame 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, 3) first portions 110 are arranged at intervals in the longitudinal direction above each other in the central portion of the floor portion 1b in the vehicle width direction, and each extends in the vehicle width direction.

[0040] Multiple (for example, 12 locations) of the second part 111 are connected to the first part 110 respectively, and extend outward in the vehicle width direction and are arranged in the front-rear direction.

[0041] The paired third parts 112 are connected to a plurality of second parts 111 on the outer side in the vehicle width direction, and extend along the side beam 10 in the front-rear direction, and are fixed to the side beam 10.

[0042] The paired fourth portions 113 extend in the front-rear direction and are configured as connection points P1, P3, P5, P6, P8, P10 connecting the plurality of first portions 110 and the plurality of second portions 111.

[0043] Each of the plurality of first portions 110, the plurality of second portions 111, the paired third portions 112, and the paired fourth portions 113 are elongated skeleton portions. In this embodiment, the plurality of first portions 110, the plurality of second portions 111, the paired third portions 112, and the paired fourth portions 113 are integrally formed. The skeleton member 11 can be formed, for example, by casting.

[0044] The plurality of second portions 111 have: portions 111a extending diagonally forward and outward in the vehicle width direction from the connection points P1, P3, P5, P6, P8, P10 with the first portion 110; and portions 111b extending diagonally backward and outward in the vehicle width direction from the connection points P1, P3, P5, P6, P8, P10 with the first portion 110. In the longitudinal direction, the diagonally forward extending portions 111a and the diagonally backward extending portions 111b are alternately arranged.

[0045] Furthermore, regarding the second part 111 in the middle section of the front-back direction among the plurality of second parts 111 (excluding the second part 111a located at the foremost position and the second part 111b located at the rearmost position), each second part 111 adjacent in the front-back direction is connected to the third part 112 at each connection point P2, P4, P7, P9, and is not separated in the front-back direction.

[0046] Furthermore, regarding the plurality of second parts 111, each second part 111 that is adjacent in the front-back direction is connected to the first part 110 and the fourth part 113 at the connection points P1, P3, P5, P6, P8, P10, and is not separated in the front-back direction.

[0047] 2. Detailed structure of the first part 110 and the second part 111 in the skeleton component 11 use Figures 2 to 5 The detailed structure of the first part 110 and the second part 111 in the skeleton component 11 is described. Figure 2 This is a top view of the rib arches 110R and 111R provided in the first part 110 and the second part 111 of the skeleton component 11. Figure 3 yes Figure 2 Cross-sectional view of section III-III. Figure 4 and Figure 5 This is a variation.

[0048] like Figure 2As shown, at least a portion of each of the plurality of first portions 110 and the plurality of second portions 111 in the skeleton member 11 has paired sidewall portions 110S, 111S and rib arches 11OR, 111R. In this embodiment, as an example, all first portions 110 have paired sidewall portions 110S and rib arches 110R, and all second portions 111 have paired sidewall portions 111S and rib arches 111R.

[0049] In the first part 110, the paired sidewall portions 110S extend in the vehicle width direction and are opposite to each other in the longitudinal direction. In the second part 111, the paired sidewall portions 111S extend in an oblique direction that is inclined relative to both the vehicle width direction and the longitudinal direction, and are opposite to each other in a direction orthogonal to the extension direction.

[0050] In the first part 110, a plurality of rib arches 110R connect the paired side wall portions 110S in the first part 110. In the second part 111, a plurality of rib arches 111R connect the paired side wall portions 111S in the second part 111.

[0051] like Figure 3 As shown, in this embodiment, each of the plurality of second portions 111 has a middle base 111M of each pair of sidewall portions 111S connected in the middle section in the vertical direction, and the rib arches 111R rise in the vertical direction from the middle base 111M. In addition, the sidewall surfaces 111W of the paired sidewall portions 111S and the sidewall surfaces 111W of the rib arches 11R have a draft angle θ relative to the imaginary line LN drawn in the vertical direction.

[0052] Multiple first parts 110 also have the same Figure 3 The same structure is shown, but its illustration is omitted.

[0053] However, a plurality of first parts 110 and a plurality of second parts 111 can also have Figure 4 or Figure 5 The structure shown. Specifically, it can also be as follows: Figure 4 As shown, in Modification 1, each of the plurality of second portions 111 has a lower base 111L connected in pairs of sidewall portions 111S at its lower part, and the rib arch 111R rises upward from the lower base 111L. The plurality of first portions 110 may also have... Figure 4 The same structure as shown.

[0054] Furthermore, it can also be like Figure 5 As shown, in Modification 2, each of the plurality of second portions 111 has an upper base 111U connected in pairs of sidewall portions 111S at its upper part, and the rib arch 111R hangs downward from the upper base 111U. The plurality of first portions 110 may also have... Figure 5 The same structure as shown.

[0055] 3. Fixing structure of frame member 11 to side beam 10 use Figure 6 This describes the fixing structure of the skeleton component 11 to the side beam 10. Figure 6 It is a cross-sectional view of part of the third part 112 of the side beam 10 and the frame member 11 located on the left side.

[0056] like Figure 6 As shown, the side beam 10 of the vehicle 1 according to this embodiment is formed by a combination of an outer side beam 100 and an inner side beam 101. The outer side beam 100 is located on the outer side in the vehicle width direction. The inner side beam 101 is located on the inner side in the vehicle width direction.

[0057] The outer beam 100 and the inner beam 101 each have a cap-shaped cross-section and are formed by fixing their respective flanges to form a side beam 10 with a closed cross-section structure.

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

[0059] The flange portions 112f1 and 112f2 of the third part 112 are respectively fixed to the inner beam 101 via the fixing point JP. Thus, the frame member 11 is fixed to the side beam 10. There is no particular limitation on the method of fixing the third part 112 to the inner beam 101. For example, bolts or rivets can be used for fastening, or resistance welding or laser welding can be used.

[0060] In this embodiment, the outer beam 100 and the inner beam 101 are different components from the skeleton member 11, but at least the inner beam 101 can be integrally formed with the skeleton member 11.

[0061] 4. The relationship between part 2 (111) and part 1 (110) use Figure 7 Explain the relationship between the second part 111 and the first part 110 in the skeleton component 11. Figure 7 This is a top view of the side beam 10 and the frame member 11.

[0062] like Figure 7 As shown, in this embodiment, the first part 110, the second part 111, the third part 112, and the fourth part 113 are each in the shape of a long column. In this embodiment, as an example, the width of each part 110 to 113 is the same in the longitudinal direction.

[0063] The front-to-back length (width) of the first part 110 is L110. However, the front-to-back length L110 of multiple first parts 110 can be different.

[0064] The lengths of the outer ends of the second part 111 in the vehicle width direction are L111. However, the front-to-back lengths L111 of the ends of the plurality of second parts 111 may be different.

[0065] In this embodiment, the plurality of first portions 110 and the plurality of second portions 111 satisfy the following relationship: 6×L111>3×L110 ・・(Equation 1).

[0066] That is, in this embodiment, the total length (6×L111) of the plurality of second parts 111 in the front-rear direction at the two outer ends (left and right) in the vehicle width direction is longer than the total length (3×L110) of the plurality of first parts 110 in the front-rear direction.

[0067] 5. Configuration of Part 2 111, Part 3 112, and Part 4 113 Next use Figure 7 This section describes the configuration of the second part 111, the third part 112, and the fourth part 113 in the skeleton component 11.

[0068] like Figure 7 As shown, the third portion 112 and the fourth portion 113 are arranged with a gap in the vehicle width direction. In addition, as described above, the second portion 111 has a portion 111a extending obliquely forward and a portion 111b extending obliquely backward, which are alternately arranged in the front-rear direction.

[0069] If the portion 111a extending diagonally forward and the portion 111b extending diagonally backward are extracted, then in the skeleton member 11, the portion 111a, the portion 111b and the third portion 112 constitute a structural part (triangular structural part) AR1 that is triangular in shape in the top view.

[0070] Furthermore, if the portion 111b extending obliquely backward and the portion 111a extending obliquely forward located behind it are extracted, then in the skeleton member 11, the portion 111b, the portion 111a, and the fourth portion 113 constitute a structural part (triangular structural part) AR2 that is triangular in shape in the top view.

[0071] The triangular structural parts AR1 and AR2, which have a hollow triangular shape inside in the top view, are parts with the same structure as the so-called truss structure. However, in the skeleton member 11 of this embodiment, the nodes of the second part 111, the third part 112, and the fourth part 113 are not fastened together by bolts or rivets, but parts 111 to 113 are connected as one unit at each node.

[0072] The skeleton member 11 of this embodiment has a structure in which triangular structural parts AR1 and AR2 are alternately arranged in the front-rear direction relative to the two outer sides of the first part 110 extending in the vehicle width direction.

[0073] 6. Effects In the vehicle 1 with the lower structure described in this embodiment, a skeleton member 11 having a plurality of first portions 110 and a plurality of second portions 111 is disposed between pairs of side beams 10. The total length (6×L111) of the plurality of second portions 111 in the longitudinal direction at their outer ends in the vehicle width direction is longer than the total length (3×L110) of the plurality of first portions 110 in the longitudinal direction. Therefore, even when a lateral collision load F0 is input to the side beam 10 from a portion with a wider range than that described in the prior art, the input lateral collision load F0 is efficiently transmitted to the first portions 110 via the second portions 111 as shown by arrows F1 and F2.

[0074] That is, the vehicle 1 with the lower structure described in this embodiment is not like... Figure 9 Unlike the prior art where the crossbeam 911 is directly connected to the side beam 910, the second portion 111 is connected to the side beam 10 over a wider area in the longitudinal direction than the first portion 110. Therefore, even when a lateral impact load F0 is input to the side beam 10 from a portion over a wider area than in the prior art, the input lateral 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 of the load input side. Therefore, in the vehicle 1, the floor portion 1b is adequately protected even in the event of a side impact from an obstacle such as a pillar.

[0075] Furthermore, in the vehicle 1 that uses the lower structure described in this embodiment, the frame member 11 has a third portion 112 located along the side beam 10 and between the second portion 111 and the side beam 10. Therefore, during a lateral collision, the collision load F0 input to the side beam 10 is dispersed in both the forward and backward directions at the third portion 112 and efficiently transmitted to the second portion 111.

[0076] Furthermore, in the vehicle 1 using the lower structure described in this embodiment, each of the adjacent second portions 111 in the longitudinal direction is interconnected with the third portion 112 at connection points P2, P4, P7, and P9. Therefore, the lateral impact load input from the side beam 10 to the third portion 112 can be efficiently dispersed to the adjacent second portions 111 in the longitudinal direction. Thus, compared to when the adjacent second portions 111 in the longitudinal direction are separated from each other at connection points P2, P4, P7, and P9 with the third portion 112, the load can be dispersed more efficiently, which is effective in protecting the floor portion 1b during a lateral collision.

[0077] Furthermore, in the vehicle 1 employing the lower structure described in this embodiment, such as Figure 6 As shown, the third part 112 is fixed to the side beam 10. Therefore, during a lateral collision, the collision load F0 input to the side beam 10 will be efficiently transferred to the third part 112.

[0078] Furthermore, in the vehicle 1 employing the lower structure according to this embodiment, each of the plurality of first portions 110 and the plurality of second portions 111 has ribs 110R and 111R connecting each of the side wall portions 110S and 111S. Therefore, compared to the absence of ribs 110R and 111R, both lightweighting and high rigidity relative to collision loads can be achieved. Thus, it is more effective for achieving lightweighting of the vehicle 1 and protecting the floor portion 1b in the event of a side collision.

[0079] Furthermore, in the vehicle 1 employing the lower structure according to this embodiment, the second portion 111 has portions 111a extending obliquely forward and portions 111b extending obliquely rearward, which are alternately arranged in the longitudinal direction. Therefore, during a side collision, the lateral collision load F0 input to the side beam 10 is transmitted as an axial force to each of the second portions 111, and also to the first portion 110 connected to the second portions 111 in the axial direction. Thus, even when the vehicle 1 is input to the side beam 10 from a range of portions that are wider than those described in the prior art, the load can still be transmitted to the first portion 110 in the axial direction.

[0080] Furthermore, in the vehicle 1 with the lower structure described in this embodiment, the adjacent forward-extending portion 111a and the backward-extending portion 111b are connected to each other at the connection points P1, P3, P5, P6, P8, and P10 of the first portion 110. Therefore, the load transmitted in the axial direction in the second portion 111 is efficiently transmitted to the first portion 110.

[0081] Furthermore, in the vehicle 1 using the lower structure according to this embodiment, the frame member 11 also has paired fourth portions 113 that connect the plurality of first portions 110 and the plurality of second portions 111 at their respective connection points P1, P3, P5, P6, P8, P10. Therefore, the load transmitted in the second portions 111 is also distributed to the adjacent first portions 110 in the longitudinal direction through the fourth portions 113. Thus, the lower structure according to this embodiment can more effectively protect the floor portion 1b in a side collision.

[0082] Furthermore, in the vehicle 1 with the lower structure described in this embodiment, a plurality of first parts 110, a plurality of second parts 111, a pair of third parts 112, and a pair of fourth parts 113 are integrally formed. Therefore, compared with each part 110 to 113 being composed of separate components, the number of parts can be reduced, and from the viewpoint of part management during manufacturing, manufacturing costs can be reduced.

[0083] As described above, the vehicle 1 with the lower structure described in this embodiment can adequately protect the floor portion 1b even when it is struck from the side by obstacles such as pillars.

[0084] [Second Embodiment] use Figure 8 The structure of the vehicle to which the lower structure according to the second embodiment applies will be described. In the vehicle to which the lower structure according to this embodiment applies, the structure of the frame member 21 is different from that of the first embodiment described above, while the other structures are the same. Therefore, the following describes the difference from the first embodiment described above, namely the structure of the frame member 21.

[0085] like Figure 8 As shown, the skeleton member 21 of this embodiment has a plurality of (for example, 3 locations) first portions 210, a plurality of (for example, 6 locations) second portions 211, and a pair of third portions 212. The plurality of first portions 210 are similar to the plurality of first portions 110 in the first embodiment described above, and are arranged at intervals in the front-rear direction at the central portion of the floor portion 1b in the vehicle width direction, and each extends in the vehicle width direction.

[0086] The paired third portions 212 are similar to the paired third portions 112 in the first embodiment described above, respectively connected to a plurality of second portions 211 on the outer side in the vehicle width direction, and respectively extending along the side beam 10 in the front-rear direction, and respectively fixed to the side beam 10.

[0087] A plurality of second portions 211 are connected to the first portion 210, and are formed in a fan shape such that their width gradually increases outward from the connection point with the first portion 210 in the vehicle width direction. The plurality of second portions 211 are arranged in the front-rear direction on the outer sides of each portion in the vehicle width direction.

[0088] A plurality of first portions 210, a plurality of second portions 211, and a pair of third portions 212 are integrally formed. The method of forming the skeleton member 21 is the same as that in the first embodiment described above, for example, casting can be used.

[0089] Regarding the plurality of second parts 211, each second part 211 that is adjacent in the front-back direction is connected to the third part 212 at the connection points P11 to P14, and is not separated in the front-back direction.

[0090] In this embodiment, the first part 210 and the third part 212 are both elongated column shapes. In this embodiment, as an example, the width of the first part 210 and the third part 212 is the same in the longitudinal direction.

[0091] The front-to-back length (width) of the first part 210 is L210. However, the front-to-back length L210 of multiple first parts 210 can be different.

[0092] The length of the outer end of the second part 211 in the vehicle width direction (the connection length with the third part 212) is L211. However, the front-to-back length L211 of the ends of the plurality of second parts 211 can be different.

[0093] In this embodiment, the plurality of first portions 210 and the plurality of second portions 211 satisfy the following relationship: 3×L211>3×L210 ・・(Equation 2).

[0094] That is, in this embodiment, the total length (3×L211) of the plurality of second parts 211 in the front-rear direction at the two outer ends (on the left and right sides) in the vehicle width direction is longer than the total length (3×L210) of the plurality of first parts 210 in the front-rear direction.

[0095] In the vehicle employing the lower structure according to this embodiment, although the structure of the frame member 21 differs from that of the first embodiment described above, the structure of the frame member 21 satisfies the aforementioned relation 2, thus achieving the same effect as the first embodiment. That is, in the lower structure according to this embodiment, a plurality of second portions 211 gradually increase in width in the longitudinal direction from their connection point with the first portion 210 outwards. Therefore, even if a lateral collision load is input to the side beam 10 from a portion with a wider range than that described in the prior art, the load can be efficiently transferred from the third portion 212 to the second portion 211. Therefore, the lower structure according to this embodiment can also adequately protect the floor during a lateral collision.

[0096] In this embodiment, similar to the first embodiment described above, the following structure can be adopted: at least a portion of the plurality of first portions 210 and the plurality of second portions 211 have paired sidewall portions and rib arches.

[0097] [Other variations] In the first embodiment described above, the frame member 11 has a third portion 112 and a fourth portion 113. In the second embodiment described above, the frame member 21 has a third portion 212. However, in this invention, the frame member does not necessarily have a third or fourth portion. When the frame member does not have a third portion, the second portion can also be fixed to the side beam.

[0098] Furthermore, in the first and second embodiments described above, a structure was adopted in which the third portions 112, 212 of the skeleton members 11, 21 were directly fixed to the side beam 10. However, the present invention can also allow other members to exist between the third portion and the side beam. As long as the structure allows the collision load of the input side beam to be transferred to the skeleton members, various connection structures can be adopted.

[0099] In the first embodiment described above, the second portion 111 of the skeleton member 11 has a portion 111a extending obliquely forward and a portion 111b extending obliquely backward, but the present invention is not limited thereto. For example, the second portion may have only a portion extending obliquely forward or only a portion extending obliquely backward.

[0100] In the second embodiment described above, the second portion 211 of the skeleton member 21 has a planar shape composed of two trapezoidal portions, but the present invention is not limited thereto. For example, it can also be a shape in which the length (width) in the front-to-back direction increases exponentially or quadratically in a top view.

[0101] In the first embodiment described above, the first portion 110 and the second portion 111 of the skeleton member 11 respectively have sidewall portions 110S, 111S and rib arches 110R, 111R, but the present invention is not limited thereto. Both the first and second portions can be portions with a solid rod shape without rib arches. Alternatively, rib arches may be present only in a portion of a plurality of first portions and a plurality of second portions.

[0102] In the first and second embodiments described above, the frame members 11 and 21 are integrally formed, but the present invention is not limited thereto. For example, the first and second parts can also be fastened together by bolts or rivets, or they can be fixed by welding.

[0103] Furthermore, the skeleton components do not necessarily have to be made of metal. For example, fiber-reinforced resin materials (CFRP, GFRP, etc.) can also be used, or a combination of resin materials (including fiber-reinforced resin materials) and metal materials can be used to form them.

[0104] In the first and second embodiments described above, the vertical dimensions of the frame members 11 and 21 are not specifically mentioned. However, in this invention, the vertical dimensions can be varied in various ways. For example, the vertical dimensions of the frame members may differ in the front-rear direction and the vehicle width direction for different regions, or they may differ in the first and second parts.

[0105] In the first and second embodiments described above, the floor panel is not mentioned, but it can be integrally formed as part of the frame member, or the floor panel can be fixed to the frame member.

[0106] [Numbering Explanation] 1 vehicle 1b Floor section 10 Side beams 11, 12 Skeleton Components 110, 210 Part 1 110R Rib Arch 111, 211 Part 2 111R Rib Arch 112, 212 Part 3

Claims

1. A lower structure for a vehicle, which is a lower structure of the floor of the vehicle, comprising: A pair of side beams are provided on both sides of the floor in the vehicle width direction and are formed in such a way that they extend in the front and rear directions respectively; The frame components are disposed between the paired side beams; wherein, The skeleton component has: A plurality of first portions are disposed at intervals between each other in the longitudinal direction at the central portion of the floor portion in the vehicle width direction, and are formed such that they extend in the vehicle width direction respectively; A plurality of second portions are connected to the end of the first portion and are arranged to extend outward in the vehicle width direction and are arranged in the front-rear direction; The plurality of second portions are formed such that the total length of the ends on both outer sides in the vehicle width direction in the front-rear direction is longer than the total length of the plurality of first portions in the front-rear direction.

2. The lower structure of the vehicle according to claim 1, characterized in that: The frame member also has a pair of third portions, which are respectively connected to the ends of the plurality of second portions on the outer side in the vehicle width direction, and are formed to extend along the side beam in the front-rear direction and are connected to the side beam.

3. The lower structure of the vehicle according to claim 2, characterized in that: Each of the second portions adjacent in the front-back direction is connected to the third portion at each connection point.

4. The lower structure of the vehicle according to claim 2, characterized in that: The paired third parts are respectively fixed to the paired side beams.

5. The lower structure of the vehicle according to claim 1, characterized in that: At least a portion of the plurality of first portions and the plurality of second portions have: a pair of sidewall portions formed in a manner extending along the vehicle width direction on both sides in the front-rear direction, and rib arches connecting the pair of sidewall portions.

6. The lower structure of the vehicle according to any one of claims 1 to 5, characterized in that: The plurality of second portions have: portions extending diagonally forward and outward in the vehicle width direction from the connection point with the first portion, and portions extending diagonally backward and outward in the vehicle width direction from the connection point with the first portion. The portion extending diagonally forward and the portion extending diagonally backward are alternately arranged in the front-back direction.

7. The lower structure of the vehicle according to claim 6, characterized in that: The adjacent forward-extending and backward-extending portions are connected to each other at their respective connection points with the first portion.

8. The lower structure of the vehicle according to any one of claims 1 to 5, characterized in that: The skeleton member also has a pair of fourth parts, which extend in the front-rear direction and are configured as connection points connecting the plurality of first parts and the plurality of second parts.

9. The lower structure of the vehicle according to any one of claims 1 to 5, characterized in that: The plurality of second parts each expand outwards in the vehicle width direction from the connection point with the first part, and their width in the front-to-back direction gradually increases.

10. The lower structure of the vehicle according to any one of claims 1 to 5, characterized in that: The skeleton components are integrally formed.

11. The lower structure of the vehicle according to claim 1, characterized in that: The paired side beams each have an outer beam disposed on the outer side in the vehicle width direction and an inner beam disposed on the inner side in the vehicle width direction and fixed to the outer beam. The outer beam and at least the inner beam of the outer beam constituting the side beam are integrally formed with the skeleton member.

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