Vehicle lower structure

Abstract

To provide a vehicle lower structure which can protect a floor part from a side collision load input from an obstacle, such as a pole, to a side sill during a side collision by transmitting the side collision load input thereto to a side sill at the opposite side in a vehicle width direction.SOLUTION: A frame member 11 has a pair of side beam portions 110 and an inner frame portion 111. The inner frame portion 111 includes: a plurality of first oblique beam portions 114 each of which is formed so as to extend forward along a direction from the inner side in a vehicle width direction to the outer side in the vehicle width direction; and a plurality of second oblique beam portions 115 each of which is formed so as to extend rearward along a direction from the inner side in the vehicle width direction to the outer side in the vehicle width direction. The frame member 11 has a plurality of triangular structure portions AR1 each of which is formed by the side beam portion 110 and the first oblique beam portion 114 and the second oblique beam portion 115 located adjacent to each other in a front-rear direction, and configured to continue in the front-rear direction on both sides in the vehicle width direction.SELECTED DRAWING: Figure 2

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] In passenger cars and other vehicles, research and development is ongoing to ensure the rigidity of the floor area where occupants sit and to protect the floor area in the event of a side collision.

[0003] 9, the vehicle disclosed in Patent Document 1 includes a pair of side sills 910, a floor tunnel 911, a pair of first cross members 912, and a pair of second cross members 913. The pair of side sills 910 each extend in the front-to-rear direction of the vehicle and are disposed on both sides of the floor in the vehicle width direction. The floor tunnel 911 is formed in the center of the vehicle width direction such that a portion of the floor panel bulges upward and extends in the front-to-rear direction.

[0004] Each of the pair of first cross members 912 has its inner end in the vehicle width direction joined to the floor tunnel 911, and is formed to extend diagonally forward as it goes outward in the vehicle width direction, with its outer end in the vehicle width direction joined to the side sill 910. Each of the pair of second cross members 913 has its inner end in the vehicle width direction joined to the floor tunnel 911, and is formed to extend diagonally rearward as it goes outward in the vehicle width direction, with its outer end in the vehicle width direction joined to the side sill 910.

[0005] The first cross member 912 and the second cross member 913 in the vehicle width direction are connected to each other at joints P90 with the floor tunnel 911. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-296957 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the vehicle disclosed in Patent Document 1 only includes one first cross member 912 and one second cross member 913 on each side of the floor tunnel 911, making it difficult to transmit the side impact load F90 input during a side impact to the side sill 910 on the opposite side in the vehicle width direction. Specifically, the side impact load F90 is transmitted in the longitudinal direction through the side sill 910 (load F91) and input to the first cross member 912 and the second cross member 913 (load F92). In this case, the load F92 is concentrated at the joint P90. Therefore, in the vehicle disclosed in Patent Document 1, the joint between the cross members 912, 913 and the floor tunnel 911 may break at the joint P90 during a side impact, making it difficult to transmit the side impact load F90 to the side sill 910 on the opposite side in the vehicle width direction. If the side impact load F90 cannot be transmitted to the side sill 910 on the opposite side of the vehicle width direction in this way, there is a concern that the floor portion will not be adequately protected, and may be deformed or broken in parts.

[0008] The present invention has been made to solve the above-mentioned problems, and aims to provide a vehicle undercarriage structure that can protect the floor portion by transferring the input side impact load to the side sill on the opposite side in the vehicle width direction, even when the side impact load is input to the side sill from an obstacle such as a pole during a side impact. [Means for solving the problem]

[0009] 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 a vehicle width direction and are formed so as to extend in a front-to-rear direction of the vehicle. The frame member is disposed between the pair of side sills.

[0010] The frame member has a pair of side beams and an inner frame. The pair of side beams are formed so as to extend in the fore-and-aft direction along the side sill and are connected to the side sill. The inner frame is formed by combining a plurality of beam structure parts and connects the pair of side beams together.

[0011] In the vehicle undercarriage structure according to this embodiment, the skeletal member has a plurality of triangular structural portions, each of which is formed by the side beam portion and the plurality of beam structural portions in a triangular shape in a plan view, and which are configured to be continuous in the fore-and-aft direction on both sides of the vehicle width direction.

[0012] In the vehicle understructure according to the above aspect, a frame member having multiple triangular structural portions continuous in the longitudinal direction is disposed between the side sills. The triangular structural portions, which are triangular in plan view, have higher load-bearing characteristics than a single elongated beam. Furthermore, because the frame member has multiple triangular structural portions continuous in the longitudinal direction, the side impact load is supported by the triangular structural portions of the frame member regardless of the longitudinal location of the side sill from which the side impact load is applied. Therefore, in the vehicle understructure according to the above aspect, regardless of the longitudinal location of the side sill from which the side impact load is applied, the load can be supported by the triangular structural portions and transferred from the side beam portion on the opposite side in the vehicle width direction to the side sill via the inner frame portion. As a result, the vehicle understructure according to the above aspect can adequately protect the floor portion even when a side impact load is applied to one side sill from an obstacle such as a pole during a side impact.

[0013] The triangular structural portion of the framework member in the above embodiment is similar to a so-called truss structure in that it has a triangular hollow portion inside when viewed from above. However, in the above embodiment, the connection points between the side beam portion and the multiple beam structural portions, and the connection points between the multiple beam structural portions are not limited to those fastened with bolts or rivets, but also include forms in which they are formed integrally or fixed.

[0014] In the vehicle undercarriage structure according to the above aspect, the plurality of beam structure portions may include a plurality of first diagonal beam portions, each formed to extend diagonally forward as it moves from the inside to the outside in the vehicle width direction, and each having its outer end connected to the side beam portion; and a plurality of second diagonal beam portions, each formed to extend diagonally backward as it moves from the inside to the outside in the vehicle width direction, and each having its outer end connected to the side beam portion; the first diagonal beam portions and the second diagonal beam portions are arranged alternately in the fore-and-aft direction on both sides of the vehicle width direction, and the ends of the first diagonal beam portions and the second diagonal beam portions adjacent to each other in the fore-and-aft direction are connected to each other; and each of the plurality of triangular structure portions may be composed of the side beam portion and the adjacent first diagonal beam portions and second diagonal beam portions.

[0015] In the vehicle undercarriage structure according to the above aspect, the first diagonal beam portion and the second diagonal beam portion adjacent to each other in the longitudinal direction are connected at their ends, so that no gaps are formed between the triangular structural portions in the longitudinal direction. As a result, the side impact load is distributed to the adjacent triangular structural portions in the longitudinal direction via the side beam portions, and the side impact load can be effectively transmitted to the side sill on the opposite side in the vehicle width direction.

[0016] In the vehicle substructure according to the above aspect, the plurality of beam structure portions may further include a pair of vertical beam portions each formed to extend in the fore-and-aft direction, and the pair of vertical beam portions arranged to connect the connection points of the adjacent first diagonal beam portion and the second diagonal beam portion, and when the plurality of triangular structure portions are a plurality of first triangular structure portions, the skeletal member may have a plurality of second triangular structure portions each composed of the vertical beam portion and the adjacent first diagonal beam portion and the second diagonal beam portion, and the plurality of second triangular structure portions configured to be continuous in the fore-and-aft direction on both sides of the vehicle width direction.

[0017] In the vehicle understructure according to the above aspect, the frame member also has multiple second triangular structural portions that are continuous in the fore-and-aft direction, so even if a side impact load is input to one side sill, the load can be supported by the first triangular structural portion and the second triangular structural portion and transmitted from the side beam portion on the opposite side in the vehicle width direction to the side sill via the inner frame portion. As a result, the vehicle understructure according to the above aspect can further adequately protect the floor portion even if a side impact load is input to one side sill from an obstacle such as a pole during a side impact.

[0018] The second triangular structural portion is also similar to a so-called truss structure in that it has a triangular hollow portion inside in a plan view. However, in the above embodiment, the connection points between the vertical beam portion and the adjacent first and second diagonal beam portions in the fore-and-aft direction, and the connection points between the first and second diagonal beam portions, are not limited to those fastened with bolts or rivets, but also include those formed integrally or fixed.

[0019] In the vehicle substructure according to the above aspect, the plurality of beam structure portions may further include a plurality of cross beam portions each formed to extend in the vehicle width direction, and the plurality of cross beam portions connecting a connection point between the first diagonal beam portion and the second diagonal beam portion on one side of the vehicle width direction and a connection point between the first diagonal beam portion and the second diagonal beam portion on the other side of the vehicle width direction.

[0020] In the vehicle undercarriage structure relating to the above-described aspect, the skeletal member has a cross beam portion that connects the triangular structural portions arranged on each side in the vehicle width direction, so that the side impact load input from the side sill on one side in the vehicle width direction can be transmitted to the side sill on the other side via the cross beam portion.

[0021] In the vehicle substructure relating to the above-mentioned aspect, a configuration may be adopted in which the connection point between the first diagonal beam portion and the second diagonal beam portion on one side of the vehicle width direction and the connection point between the first diagonal beam portion and the second diagonal beam portion on the other side of the vehicle width direction are directly connected.

[0022] In the vehicle undercarriage structure relating to the above-mentioned aspect, the vertices of the triangular structural portions on both sides in the vehicle width direction (the connection points between the first diagonal beam portion and the second diagonal beam portion) are directly connected to each other, so that the side impact load input from the side sill on one side in the vehicle width direction can be transmitted to the side sill on the other side via only the triangular structural portions on both sides in the vehicle width direction.

[0023] In the vehicle substructure relating to the above aspect, at least some of the plurality of beam structure portions may have a pair of side wall portions formed to extend along the extension direction of the beam structure portions, and a rib formed to connect the pair of side wall portions to each other.

[0024] In the vehicle undercarriage structure according to the above aspect, since at least some of the beam structure portions included in the frame member have ribs, it is possible to achieve both weight reduction and high rigidity against load compared to a case without ribs, which is more effective in protecting the floor portion in the event of a side collision while reducing the vehicle weight.

[0025] In the vehicle undercarriage structure according to the above aspect, the framework member may be integrally formed.

[0026] 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.

[0027] In the vehicle undercarriage structure according to the above aspect, a configuration may be employed in which the pair of side beam portions are fixed to the pair of side sills, respectively.

[0028] In the vehicle undercarriage structure according to the above aspect, the side beam portion is fixed to the side sill, so that the side impact load input to the side sill during a side impact is efficiently transmitted to the inner framework portion via the side beam portion.

[0029] 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.

[0030] 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]

[0031] In the vehicle undercarriage structures according to each of the above aspects, even if a side impact load is input to the side sill from an obstacle such as a pole during a side collision, the input side impact load can be transmitted to the side sill on the opposite side in the vehicle width direction, thereby protecting the floor portion. [Brief explanation of the drawings]

[0032] [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] FIG. 2 is a plan view showing the configuration of a framework member. [Figure 3] FIG. 4 is a plan view showing ribs provided on the skeletal member. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. [Figure 5] FIG. 10 is a cross-sectional view showing the configuration of a rib according to Modification 1. [Figure 6] FIG. 10 is a cross-sectional view showing the configuration of a rib according to Modification 2. [Figure 7] FIG. 4 is a cross-sectional view showing a joining structure of a framework member to a side sill. [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

[0033] 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.

[0034] In addition, in the figures used in the following description, "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. Furthermore, in the following description, the front-to-back direction of the vehicle may be simply referred to as the "front-to-back direction," and the up-to-down direction of the vehicle may be simply referred to as the "up-to-down direction."

[0035] [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.

[0036] 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.

[0037] 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.

[0038] The skeleton member 11 has a pair of side beam portions 110 and an inner skeleton portion 111. The pair of side beam portions 110 are each formed to extend in the front-to-rear direction along the side sill 10 and are connected to the side sill 10. The inner skeleton portion 111 is formed by combining a plurality of beam structure portions (each portion having an elongated shape) and connects the pair of side beam portions 110 together.

[0039] The multiple beam structure parts that make up the inner skeleton 111 and their combinations will be described in detail later.

[0040] The framework member 11 has a plurality of triangular structural portions (first triangular structural portions) AR1 (three on each side, six in total) and a plurality of triangular structural portions (second triangular structural portions) AR2 (two on each side, four in total). Each of the triangular structural portions AR1 and AR2 is configured to have a triangular frame shape (triangular frame shape) in plan view by combining a pair of side beam portions 110 with a plurality of beam structural portions that constitute the inner framework member 111.

[0041] The plurality of triangular structural portions AR1 are arranged so as to be continuous in the front-rear direction on each of the left and right sides. The plurality of triangular structural portions AR2 are also arranged so as to be continuous in the front-rear direction on each of the left and right sides.

[0042] 2. Detailed structure of the inner skeleton 111 and triangular structural parts AR1 and AR2 The detailed structure of the inner skeleton 111 and the triangular structural portions AR1 and AR2 will be described with reference to Fig. 2. Fig. 2 is a plan view showing the skeleton member 11 in isolation.

[0043] 2, the inner framework 111 has a plurality of cross beam portions 112, a pair of left and right vertical beam portions 113, a plurality of first diagonal beam portions 114, and a plurality of second diagonal beam portions 115. The plurality of (for example, three) cross beam portions 112 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.

[0044] The pair of left and right vertical beam portions 113 each extend in the front-rear direction and are arranged so as to connect the left and right ends of the multiple horizontal beam portions 112.

[0045] Each of the multiple first diagonal beam portions 114 is connected at its inner end in the vehicle width direction to the cross beam portion 112 and the longitudinal beam portion 113, and at its outer end to the side beam portion 110. The multiple first diagonal beam portions 114 are arranged so as to extend diagonally forward from connection points P1, P3, P5, P6, P8, and P10 with the cross beam portion 112 and the longitudinal beam portion 113 toward the outer side in the vehicle width direction.

[0046] Each of the plurality of second diagonal beam portions 115 is connected at its inner end in the vehicle width direction to the cross beam portion 112 and the longitudinal beam portion 113, and at its outer end to the side beam portion 110. The plurality of second diagonal beam portions 115 are arranged so as to extend obliquely rearward from connection points P1, P3, P5, P6, P8, and P10 with the cross beam portion 112 and the longitudinal beam portion 113 toward the outer side in the vehicle width direction.

[0047] The first diagonal beam portions 114 and the second diagonal beam portions 115 are arranged alternately in the front-rear direction. The first diagonal beam portions 114 and the second diagonal beam portions 115 adjacent in the front-rear direction have their inner ends in the vehicle width direction connected at connection points P1, P3, P5, P6, P8, and P10 without any gap in the front-rear direction.

[0048] Further, the second diagonal beam portion 115 and the first diagonal beam portion 114 that are adjacent in the longitudinal direction are connected at their outer ends in the vehicle width direction at connection points P2, P4, P7, and P9 without any separation in the longitudinal direction.

[0049] In the skeleton member 11, the pair of left and right side beam portions 110, the pair of left and right vertical beam portions 113, the plurality of first diagonal beam portions 114, and the plurality of second diagonal beam portions 115 are each a long skeleton portion. In this embodiment, the skeleton member 11 is configured by integrally forming the pair of left and right side beam portions 110, the plurality of horizontal beam portions 112, the pair of left and right vertical beam portions 113, the plurality of first diagonal beam portions 114, and the plurality of second diagonal beam portions 115. The skeleton member 11 can be formed, for example, by casting.

[0050] In the framework member 11, the first diagonal beam portion 114, the second diagonal beam portion 115 disposed behind it, and the side beam portions 110 form a triangular structural portion AR1 having a triangular frame shape in a plan view. As described above, the triangular structural portion AR1 is continuous in the front-to-rear direction between the left and right vertical beam portions 113 and the side beam portions 110.

[0051] In the framework member 11, the second diagonal beam portion 115, the first vertical beam portion 113 disposed behind it, and the vertical beam portion 113 form a triangular structural portion AR2 having a triangular frame shape in plan view (triangular frame shape). The triangular structural portion AR2 also continues in the front-to-rear direction between the left and right vertical beam portions 113 and the side beam portions 110.

[0052] In the front-rear direction, the triangular structure portions AR1 and the triangular structure portions AR2 are arranged alternately.

[0053] 3. Detailed structure of the beam structure part in the inner skeleton part 111 The detailed structure of the beam structure portions in the inner skeleton portion 111 will be described with reference to Figs. 3 to 6. Fig. 3 is a plan view showing the detailed structure of the beam structure portions (horizontal beam portion 112, vertical beam portion 113, first diagonal beam portion 114, second diagonal beam portion 115) in the inner skeleton portion 111. Fig. 4 is a cross-sectional view showing a cross section taken along line IV-IV in Fig. 3. Figs. 5 and 6 show modified examples.

[0054] As shown in FIG. 3, the beam structure portion of the inner skeleton 111 has a pair of side walls 112S, 113S, 114S, and 115S, and ribs 112R, 113R, 114R, and 115R.

[0055] In this embodiment, all of the beam structure portions have the ribs 112R, 113R, 114R, and 115R, but only some of the beam structure portions may have ribs.

[0056] The pair of side walls 112S of the cross beam portion 112 are each formed to extend in the vehicle width direction and are formed to face each other at a distance in the front-rear direction. The pair of side walls 114S of the first diagonal beam portion 114 are each formed to extend in a diagonal direction inclined with respect to the vehicle width direction and the front-rear direction and are formed to face each other in a direction perpendicular to the extending directions. The pair of side walls 115S of the second diagonal beam portion 115 are each formed to extend in a diagonal direction inclined with respect to the vehicle width direction and the front-rear direction and are formed to face each other in a direction perpendicular to the extending directions. The pair of side walls 113S of the vertical beam portion 113 are each formed to extend in the front-rear direction and are formed to face each other in the vehicle width direction.

[0057] Each of the plurality of ribs 112R in the cross beam portion 112 is formed so as to connect a pair of side wall portions 112S in the cross beam portion 112. Each of the plurality of ribs 114R in the first diagonal beam portion 114 is formed so as to connect a pair of side wall portions 114S in the first diagonal beam portion 114. Each of the plurality of ribs 115R in the second diagonal beam portion 115 is formed so as to connect a pair of side wall portions 115S in the second diagonal beam portion 115. Each of the plurality of ribs 113R in the vertical beam portion 113 is formed so as to connect a pair of side wall portions 113S in the vertical beam portion 113.

[0058] 4, the vertical beam portion 113 has an intermediate base 113M connecting a pair of side wall portions 113S together in the vertical middle portion, and the ribs 113R are provided to rise up in the vertical direction from the intermediate base 113M. The side wall surfaces 113W of the pair of side wall portions 113S and the side wall surfaces 113W of the ribs 113R are formed to have a draft angle θ with respect to an imaginary line LN drawn in the vertical direction.

[0059] Although not shown, the cross beam portion 112, the plurality of first diagonal beam portions 114, and the plurality of second diagonal beam portions 115 also have the same configuration as that shown in FIG.

[0060] However, at least some of the horizontal beam portion 112, the vertical beam portion 113, the plurality of first diagonal beam portions 114, and the plurality of second diagonal beam portions 115 may have the configuration shown in Fig. 5 or 6. Specifically, as shown in Fig. 5, the vertical beam portion 113 in Modification 1 may have a lower base 113L at its lower part that connects a pair of side wall portions 113S, and the rib 113R may be provided so as to rise upward from the lower base 113L. The horizontal beam portion 112, the plurality of first diagonal beam portions 114, and the plurality of second diagonal beam portions 115 may also have the same configuration as shown in Fig. 5.

[0061] 6, the vertical beam portion 113 in Modification 2 may have an upper base 113U at its upper portion that connects a pair of side wall portions 113S, and the rib 113R may be provided to hang down from the upper base 113U. The horizontal beam portion 112, the plurality of first diagonal beam portions 114, and the plurality of second diagonal beam portions 115 may also have the same configuration as shown in FIG.

[0062] 4. 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. 7. Fig. 7 is a cross-sectional view showing the side sill 10 disposed on the left side and a part of the side beam portion 110 of the framework member 11.

[0063] As shown in Fig. 7, 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.

[0064] The side sill outer 100 and the side sill inner 101 each have a hat-shaped cross section, and their flange portions are fixed together to form a side sill 10 having a closed cross section.

[0065] The side beam portion 110 of the framework member 11 has a flange portion 110f1 formed along part of the upper surface of the side sill inner panel 101, and a flange portion 110f2 formed along part of the inner wall surface of the side sill inner panel 101.

[0066] The flange portions 110f1 and 110f2 of the side beam portion 110 are fixed to the side sill inner panel 101 at fixing points JP, respectively. This fixes the frame member 11 to the side sill 10. The method for fixing the side beam portion 110 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.

[0067] In this embodiment, the side sill outer 100 and the side sill inner 101 are separate members from the frame member 11, but it is also possible to form at least the side sill inner 101 integrally with the frame member 11. When at least the side sill inner 101 is formed integrally with the frame member 11 in this way, the number of parts can be reduced compared to when the side sill inner 101 is configured as a separate member from the frame member 11. Therefore, it is possible to reduce 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.

[0068] 5.Effects In a vehicle 1 to which the undercarriage structure according to this embodiment is applied, a frame member 11 having multiple triangular structural portions AR1 extending in the longitudinal direction is disposed between side sills 10. The triangular structural portions AR1, which have a triangular frame shape in a plan view, have higher load-bearing characteristics than a single beam. As shown in FIG. 2 , the frame member 11 has multiple triangular structural portions AR1 extending in the longitudinal direction. Therefore, regardless of the location of a side impact load F0 applied to the side sill 10 in the longitudinal direction, the triangular structural portions AR1 of the frame member 11 support the side impact load F0. Therefore, even if a side impact load F0 is applied to any location of one side sill 10 in the longitudinal direction, the vehicle 1 can support the load F0 with the triangular structural portions AR1 and transfer the load F0 from the side beam portion 110 on the opposite side in the vehicle width direction to the side sill 10 via the inner frame portion 111, as indicated by F1 in FIG. 2 . This allows the vehicle 1 to adequately protect the floor portion 1b even in the event of a side collision with an obstacle such as a pole.

[0069] The triangular structural portion AR1 of the framework member 11 is similar to a so-called truss structure in that it has a triangular hollow portion inside in a plan view. However, connection points P2, P4, P7, and P9 between the side beam portion 110 and the first diagonal beam portion 114 and the second diagonal beam portion 115, and connection points P1, P3, P5, P6, P8, and P10 between the first diagonal beam portion 114 and the second diagonal beam portion 115 and the cross beam portion 112 are formed to be integrally continuous with each other. For this reason, the triangular structural portion AR1 differs from a truss structure.

[0070] Furthermore, in the vehicle 1 to which the undercarriage structure according to this embodiment is applied, the first diagonal beam portion 114 and the second diagonal beam portion 115 adjacent in the longitudinal direction are connected at their ends (connection points P1, P3, P5, P6, P8, and P10), so that no gaps are formed between the triangular structural portions AR1 in the longitudinal direction. Therefore, the side impact load F0 is distributed to the adjacent triangular structural portions AR1 in the longitudinal direction via the side beam portion 110 (loads F2 and F3), and the side impact load F0 can be effectively transmitted to the side sill 10 on the opposite side in the vehicle width direction (load F1).

[0071] Furthermore, in the vehicle 1 to which the undercarriage structure according to this embodiment is applied, the frame member 11 has, in addition to the triangular structural portion AR1, multiple triangular structural portions (second triangular structural portions) AR2 that are continuous in the longitudinal direction, so that even when a side impact load F0 is input to one side sill 10, the load F0 can be supported by the triangular structural portions AR1 and AR2 and transmitted from the side beam portion 110 on the opposite side in the vehicle width direction to the side sill 10 via the inner frame portion 111 (load F1). This allows the vehicle 1 to more sufficiently protect the floor portion 1b even when an obstacle such as a pole collides with it from the side.

[0072] The triangular structural portion AR2 is also similar to a so-called truss structure in that it has a triangular hollow portion inside in a plan view. However, in this embodiment, connection points P2, P4, P7, and P9 between the vertical beam portion 112 and the first diagonal beam portion 114 and the second diagonal beam portion 115 adjacent thereto in the front-to-rear direction, and connection points P1, P3, P5, P6, P8, and P10 between the first diagonal beam portion 114 and the second diagonal beam portion 115 and the vertical beam portion 113 are integrally formed with each other. Therefore, the triangular structural portion AR2 is also different from a truss structure.

[0073] Furthermore, in the vehicle 1 to which the undercarriage structure of this embodiment is applied, the skeletal member 11 has a cross beam portion 112 that connects the triangular structural portions AR1 arranged on each side in the vehicle width direction, so that the side impact load F0 input from the side sill 10 on one side in the vehicle width direction can be transmitted to the side sill 10 on the other side via the cross beam portion 112 (load F1).

[0074] Furthermore, in the vehicle 1 to which the undercarriage structure according to this embodiment is applied, each of the portions 112 to 115 of the frame member 11 has the ribs 112R, 113R, 114R, and 115R, so that the vehicle 1 is both lighter in weight and has higher rigidity against load than when the frame member 11 does not have ribs. Therefore, the vehicle 1 is more effectively protected from a side collision while reducing the weight of the vehicle 1.

[0075] Furthermore, in the vehicle 1 to which the undercarriage structure of this embodiment is applied, the parts 110, 112 to 115 that make up the skeletal member 11 are integrally formed, so the number of parts can be reduced compared to when each part is made up of a separate part, and it is possible to reduce manufacturing costs from the perspective of reducing the number of steps required for parts management during manufacturing and the number of steps required for connecting each part.

[0076] Furthermore, in the vehicle 1 to which the undercarriage structure of this embodiment is applied, the side beam portion 110 is fixed to the side sill 10, so that the load F0 input to the side sill 10 during a side collision is efficiently transmitted to the inner skeleton portion 111 via the side beam portion 110.

[0077] As described above, in the lower structure of the vehicle 1 according to this embodiment, even if a side impact load is input from an obstacle such as a pole during a side collision, the input side impact load can be transmitted to the side sill on the opposite side in the vehicle width direction, thereby protecting the floor portion.

[0078] [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.

[0079] As shown in Fig. 8, the framework member 21 of this embodiment has a pair of side beam portions 210 and an inner framework portion 211. The pair of side beam portions 210 are each formed to extend in the front-to-rear direction along the side sill (not shown in Fig. 8) and are connected to the side sill. The inner framework portion 211 is formed by combining a plurality of beam structure portions and connects the pair of side beam portions 210 together.

[0080] The inner skeleton 211 has a vertical beam portion 213, a plurality of (for example, two on each of the left and right) first diagonal beam portions 214, and a plurality of (for example, two on each of the left and right) second diagonal beam portions 215. Unlike the inner skeleton 111 of the first embodiment, the inner skeleton 211 does not have a horizontal beam portion extending in the vehicle width direction at a middle portion in the vehicle width direction.

[0081] The vertical beam portion 213 of the inner skeleton 211 is formed so as to extend in the front-rear direction in the center portion in the vehicle width direction. In this embodiment, the vertical beam portion 213 is disposed in the approximate center portion in the vehicle width direction.

[0082] Each of the plurality of first diagonal beam portions 214 is connected at its inner end in the vehicle width direction to the longitudinal beam portion 213, and at its outer end to the side beam portion 210. The plurality of first diagonal beam portions 214 are arranged so as to extend diagonally forward from the connection point with the longitudinal beam portion 213 toward the outer side in the vehicle width direction.

[0083] Each of the plurality of second diagonal beam portions 215 is connected at its inner end in the vehicle width direction to the longitudinal beam portion 213, and at its outer end to the side beam portion 210. The plurality of second diagonal beam portions 215 are arranged so as to extend obliquely rearward from the connection point with the longitudinal beam portion 213 toward the outer side in the vehicle width direction.

[0084] The first diagonal beam portions 214 and the second diagonal beam portions 215 are arranged alternately in the front-rear direction. The first diagonal beam portions 214 and the second diagonal beam portions 215 adjacent in the front-rear direction have their inner ends in the vehicle width direction connected to the longitudinal beam portions 213 at their connection points without any separation in the front-rear direction.

[0085] In addition, the second diagonal beam portion 215 and the first diagonal beam portion 214, which are adjacent in the longitudinal direction, have their outer ends in the vehicle width direction connected to the side beam portion 210 at the connection point without any separation in the longitudinal direction.

[0086] In the skeleton member 21, the pair of left and right side beam portions 210, the vertical beam portion 213, the plurality of first diagonal beam portions 214, and the plurality of second diagonal beam portions 215 are each a long skeleton portion. In this embodiment, the skeleton member 21 is configured by integrally forming the pair of left and right side beam portions 210, the vertical beam portion 213, the plurality of first diagonal beam portions 214, and the plurality of second diagonal beam portions 215. The skeleton member 21 can be formed, for example, by casting.

[0087] The framework member 21 has a plurality of triangular structural portions (first triangular structural portions) AR3 (two on each side, four in total) and a plurality of triangular structural portions (second triangular structural portions) AR4 (one on each side, two in total). Each of the triangular structural portions AR3 and AR4 is configured in the shape of a triangular picture frame in plan view by combining a pair of side beam portions 210 with a plurality of beam structural portions that constitute the inner framework member 211.

[0088] Specifically, the triangular structural portion AR3 is composed of a side beam portion 210 and a first diagonal beam portion 214 and a second diagonal beam portion 215 that are adjacent in the longitudinal direction. Here, the triangular structural portion AR3 formed on the left side in the vehicle width direction and the triangular structural portion AR3 formed on the right side are directly connected at the connection portions between the first diagonal beam portion 214 and the second diagonal beam portion 215. In other words, in this embodiment, the triangular structural portion AR3 formed on the left side in the vehicle width direction and the triangular structural portion AR3 formed on the right side are directly connected without an intervening cross beam portion.

[0089] The triangular structural portion AR4 is composed of a vertical beam portion 213 and adjacent second diagonal beam portions 215 and first diagonal beam portions 214 in the longitudinal direction. The triangular structural portion AR4 formed on the left side in the vehicle width direction and the triangular structural portion AR4 formed on the right side are configured to share the vertical beam portion 213.

[0090] Although the vehicle to which the undercarriage according to this embodiment is applied differs in the structure of the frame member 21 from that of the first embodiment, the frame member 21 includes the triangular structural portions AR3 and AR4, thereby achieving the same effects as the first embodiment. That is, in this embodiment, the frame member 21 includes the triangular structural portions AR3 and AR4, so that the triangular structural portions AR3 and AR4 support the side impact load regardless of the longitudinal position of the side sill from which the side impact load is applied. Therefore, even if the side impact load is applied to any longitudinal position of one side sill, the vehicle can transfer the load from the side sill portion 210 on the opposite side in the vehicle width direction to the side sill while supporting the load with the triangular structural portions AR3 and AR4. This ensures that the vehicle floor portion can be adequately protected even when a side impact load is applied from an obstacle such as a pole during a side collision.

[0091] In this embodiment as well, at least a part of the inner skeleton 211 may have a pair of side walls and a rib, similar to the first embodiment.

[0092] [Other variations] In the first embodiment, the inner skeleton 111 has the horizontal beam portion 112, the vertical beam portion 113, the first diagonal beam portion 114, and the second diagonal beam portion 115. However, in the present invention, the portions of the inner skeleton are not limited to this. For example, the vertical beam portion 113 may be omitted, or another beam structure portion may be included. In the second embodiment, the inner skeleton 211 has the vertical beam portion 213, the first diagonal beam portion 214, and the second diagonal beam portion 215. However, in the present invention, the portions of the inner skeleton are not limited to this. For example, the vertical beam portion 213 may be omitted, or another beam structure portion may be included.

[0093] Furthermore, in the first and second embodiments, a structure is adopted in which the side beam portions 110, 210 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 side beam 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 members.

[0094] In the first and second embodiments, the skeletal members 11 and 21 are configured to have triangular structural portions (second triangular rainfall portions) AR2 and AR4 in addition to the triangular structural portions AR1 and AR3, but in the present invention, the skeletal members do not necessarily have to have the second triangular structural portions.

[0095] In the first embodiment, each of the portions 112 to 115 constituting the inner skeleton 111 has a pair of side walls 112S, 113S, 114S, and 114S and ribs 112R, 113R, 114R, and 115R, respectively. However, the present invention is not limited to this. None of the portions constituting the inner skeleton may have ribs. Alternatively, only some of the portions may have ribs.

[0096] 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 side beam portions and the first and second diagonal beam portions may be fastened together with bolts or rivets, or the vertical beam portions and the first and second diagonal beam portions may be fastened together with bolts or rivets.

[0097] In the first and second embodiments, no particular mention was made of the vertical size of each part of the framework members 11 and 21, but the present invention allows various settings for the vertical size of each part. Also, the vertical size of each part does not need to be uniform across the framework members, and can be set for each installation area.

[0098] Although no mention was made of the floor panel in the first and second embodiments, the floor panel can be integrally formed as part of the skeletal member, or the floor panel can be a separate member from the skeletal member and fixed to the skeletal member. [Explanation of symbols]

[0099] 1 vehicle 1b Floor section 10 Side sill 11,21 Skeleton members 110,210 Side beam part 111,211 Medial skeletal part 112 Cross beam part 112R, 113R, 114R, 115R Rib 113,213 Longitudinal beam section 114,214 1st diagonal beam part 115,215 2nd diagonal beam part AR1,AR3 1st triangular structure AR2,AR4 2nd triangular structure

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 a vehicle width direction and each extending in a front-rear direction of the vehicle; a framework member disposed between the pair of side sills; Equipped with The skeletal member is a pair of side beam portions each formed to extend in the front-rear direction along the side sill and connected to the side sill; an inner skeleton portion formed by combining a plurality of beam structure portions and connecting the pair of side beam portions; and The framework member has a plurality of triangular structural portions, each of which is formed by the side beam portion and the plurality of beam structural portions in a triangular shape in a plan view, and which are configured to be continuous in the front-rear direction on both sides in the vehicle width direction. Vehicle undercarriage.

2. the plurality of beam structure portions include a plurality of first diagonal beam portions each formed to extend obliquely forward as it moves from the inner side in the vehicle width direction to the outer side in the vehicle width direction, and each having an outer end portion in the vehicle width direction connected to the side beam portion; and a plurality of second diagonal beam portions each formed to extend obliquely rearward as it moves from the inner side in the vehicle width direction to the outer side in the vehicle width direction, and each having an outer end portion in the vehicle width direction connected to the side beam portion, the first diagonal beam portions and the second diagonal beam portions are alternately arranged in the front-rear direction on both sides in the vehicle width direction, and the first diagonal beam portions and the second diagonal beam portions adjacent to each other in the front-rear direction are connected at their ends, Each of the plurality of triangular structural portions is composed of the side beam portion, and the adjacent first diagonal beam portion and the adjacent second diagonal beam portion. The vehicle undercarriage according to claim 1 .

3. the plurality of beam structure portions further include a pair of vertical beam portions each formed to extend in the front-rear direction, and the pair of vertical beam portions arranged to connect connection points between the adjacent first diagonal beam portion and the adjacent second diagonal beam portion, When the plurality of triangular structure portions are a plurality of first triangular structure portions, the framework member has a plurality of second triangular structural portions each formed by the longitudinal beam portion and the adjacent first diagonal beam portion and second diagonal beam portion, the plurality of second triangular structural portions being configured to be continuous in the front-rear direction on both sides in the vehicle width direction, The vehicle undercarriage according to claim 2.

4. The plurality of beam structure portions further include a plurality of cross beam portions each formed to extend in the vehicle width direction, and the plurality of cross beam portions connecting a connection portion between the first diagonal beam portion and the second diagonal beam portion on one side in the vehicle width direction and a connection portion between the first diagonal beam portion and the second diagonal beam portion on the other side in the vehicle width direction. The vehicle undercarriage according to claim 2.

5. a connection portion between the first diagonal beam portion and the second diagonal beam portion on one side in the vehicle width direction and a connection portion between the first diagonal beam portion and the second diagonal beam portion on the other side in the vehicle width direction are directly connected; The vehicle undercarriage according to claim 2.

6. At least some of the beam structure portions have a pair of side wall portions formed to extend along the extension direction of the beam structure portions, and a rib formed to connect the pair of side wall portions.

6. The vehicle underbody structure according to claim 1.

7. The skeletal member is integrally formed.

6. The vehicle underbody structure according to claim 1.

8. The pair of side beam portions are fixed to the pair of side sills, respectively.

6. The vehicle underbody structure according to claim 1.

9. 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.

6. The vehicle underbody structure according to claim 1.

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