Vehicle body frame structure

Abstract

To provide a vehicle body frame structure that can achieve high collision energy absorption characteristics while suppressing increases in weight and manufacturing costs.SOLUTION: The vehicle body frame structure includes a side sill 10 extending in the vehicle longitudinal direction and a reinforcing member 103 housed in a hollow portion 10a of the side sill 10. The reinforcing member 103 is formed with a plurality of closed cross-section cells 103a, 103b, each having an axis in the vehicle width direction, that are continuous in the vehicle longitudinal direction. Each of the plurality of closed cross-section cells 103a, 103b has a hexagonal closed cross-section and is formed so as to share a first cell wall with the closed cross-section cell 103a, 103b adjacent in the vehicle longitudinal direction. Each of the plurality of closed cross-section cells 103a, 103b is formed so that the side length of the first cell wall is longer than the side length of at least one of the cell walls of that cell excluding the first cell wall.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle body frame structure. [Background technology]

[0002] BACKGROUND ART Vehicles such as automobiles have a body made up of a plurality of skeletal members joined together. The skeletal members that form the framework of the body are required to ensure high rigidity while suppressing an increase in weight.

[0003] Patent Document 1 discloses a vehicle body structure including a hollow side sill and a reinforcing member disposed inside the side sill. The reinforcing member employed in the vehicle body structure of Patent Document 1 will be described with reference to Fig. 8(a).

[0004] As shown in FIG. 8(a), the reinforcing member 903 in Patent Document 1 is formed using two plates (an upper plate member 904 and a lower plate member 905), each of which has been bent. The reinforcing member 903 has a plurality of closed cross-section cells 903a arranged along the longitudinal direction of the side sill (the front-to-rear direction of the vehicle). Each of the plurality of closed cross-section cells 903a has a hollow columnar shape extending in a direction perpendicular to the plane of FIG. 8(a), and has a hexagonal shape (honeycomb shape) in side view. In the reinforcing member 903, a joint 903b is provided between adjacent closed cross-section cells 903a, joining the upper plate member 904 and the lower plate member 905. At the joint 903b, the upper plate member 904 and the lower plate member 905 are overlapped and joined to each other by welding or the like.

[0005] Here, as a measure to improve the energy absorption performance when a collision load is input to the side sill from the outside in the vehicle width direction in Patent Document 1, it is possible to arrange adjacent closed cross-section cells 903a continuously and increase the arrangement area in the height direction. Specifically, as shown in Fig. 8(b), a possible reinforcing member 953 can be formed using three bent plate members (an upper plate member 954, a middle plate member 955, and a lower plate member 956), each extending in the longitudinal direction of the side sill. This makes it possible to configure a reinforcing member 953 having multiple closed cross-section cells 953a, 953b arranged continuously in the front-to-rear direction of the vehicle with inclined wall portions 955a to 955d of the middle plate member 955 sandwiched therebetween, and having a height L95 that is higher than the reinforcing member 903 shown in Fig. 8(a). In the reinforcing member 953 having such a structure, the honeycomb-shaped closed cross-sectional cells 953a, 953b are continuous, and the area in the height direction can be made wider than that of the reinforcing member 903 of Patent Document 1. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-24350 Summary of the Invention [Problem to be solved by the invention]

[0007] However, with the reinforcing member 953 shown in Fig. 8(b), it is considered difficult to increase the amount of energy absorbed (EA) when a collision load is input from the outside in the vehicle width direction to the side sill, which is a framework member. That is, with the reinforcing member 953 in which multiple closed cross-sectional cells 953a, 953b are connected in a zigzag shape, the size of each closed cross-sectional cell 953a, 953b becomes small, making axial compression unstable. For this reason, it is considered difficult to increase the amount of energy absorbed with the reinforcing member 953 when a collision load is input from the outside in the vehicle width direction.

[0008] Furthermore, it is considered difficult to reduce the weight and manufacturing costs of the reinforcing member 953 shown in FIG. 8(b). Specifically, in the reinforcing member 953, the plate members 954-956 are bent so that the multiple closed cross-sectional cells 953a, 953b are connected in a zigzag shape, which results in a long actual length of each of the plate members 954-956. This inevitably increases the weight of the reinforcing member 953, making it difficult to reduce the weight. Furthermore, the reinforcing member 953 requires joining the numerous plate members 954-956 at their overlapping portions (wall portions 954a, 955e-955g, 956a, 956b), which requires complex manufacturing processes. This makes it difficult to reduce the manufacturing costs of the reinforcing member 953.

[0009] The present invention has been made to solve the above-mentioned problems, and aims to provide a vehicle body frame structure that can achieve high collision energy absorption characteristics while suppressing increases in weight and manufacturing costs. [Means for solving the problem]

[0010] A vehicle body frame structure according to one aspect of the present invention includes a frame member and a reinforcing member. The frame member is a member that forms the frame of the vehicle body, has a hollow portion inside, and extends in a first direction. The reinforcing member is a reinforcing member that is housed in the hollow portion of the frame member, and has a plurality of cells formed in a hollow column shape by a plurality of cell walls, each having an axis in a second direction that intersects the first direction, and the plurality of cells are formed so as to be continuously aligned in the first direction.

[0011] In the vehicle body frame structure according to this aspect, the plurality of cells in the reinforcing member each have an n-sided polygon (n: an even number of 4 or more) in a cross section perpendicular to the second direction, and are formed so that adjacent cells in the first direction share a cell wall. When the cell wall shared by the adjacent cells is a first cell wall, each of the plurality of cells is formed so that the side length of the first cell wall in the cross section perpendicular to the second direction is longer than the side length of at least one of the other cell walls that form the cell.

[0012] In a vehicle to which the vehicle body frame structure according to the above embodiment is applied, each cell is formed so that the side length of the first cell wall is longer than the side length of the at least one cell wall, so that compared to a case in which multiple regular n-gon cells are formed, it is possible to ensure a large cross-sectional area of ​​the closed cross section of each cell while continuously arranging cells having n-gonal cross sections in the first direction. Therefore, compared to a case in which a configuration such as that shown in Figure 8(b) is adopted, the vehicle according to the above embodiment can achieve high collision energy absorption characteristics while suppressing increases in weight and manufacturing costs.

[0013] In the vehicle body frame structure according to the above aspect, an ellipse or an oval is inscribed in the closed cross section of each cell, rather than a circle. However, the shape of the cell may not be inscribed in all cell walls forming the cell, and some cell walls may not be inscribed in an oval. By adopting such a cell shape, the vehicle body frame structure according to the above aspect can achieve the above-mentioned functions and effects.

[0014] In the vehicle body frame structure according to the above aspect, when a direction orthogonal to the first direction in the orthogonal cross section is defined as a third direction, each of the plurality of cells has a hexagonal shape in the orthogonal cross section, and includes a pair of second cell walls extending in the first direction and facing each other in the third direction, and a pair of third cell walls connecting an end side in the first direction of one of the pair of second cell walls to each of end sides in the third direction of the pair of first cell walls, and each of the plurality of cells is formed such that a side length of the first cell wall is longer than a side length of the third cell wall. That is, in the vehicle body frame structure according to the present aspect, the cells have a hexagonal shape in the cross section, and at least one of the cell walls is a third cell wall.

[0015] In a vehicle to which the body frame structure according to the above embodiment is applied, the closed cross-sectional shape of each cell is hexagonal, and each cell is configured so that the side length of each of the pair of first cell walls is longer than the side length of the third cell wall. Therefore, compared to when regular hexagonal cell structures are connected as shown in Figure 8(b), it is possible to connect multiple cells in the first direction while ensuring a large cross-sectional area of ​​the hexagonal cells.

[0016] In the vehicle body skeleton structure relating to the above-mentioned aspect, the skeleton member may be a side sill arranged on the outer side of the floor portion of the vehicle in the vehicle width direction and formed to extend in the fore-and-aft direction of the vehicle, and a cross member having one end connected to the side sill and extending in the vehicle width direction is arranged on the floor portion of the vehicle, and when viewed from the side of the vehicle, the reinforcing member may be arranged in an area overlapping with the cross member.

[0017] In a vehicle to which the vehicle body frame structure according to the above aspect is applied, the reinforcing member is arranged in an area that overlaps with the cross member in a side view, so that when a collision load is input from the side of the vehicle to the side sill, which is a frame member, the load is transmitted to the cross member with high efficiency via the reinforcing member. Therefore, in a vehicle to which the vehicle body frame structure according to the above aspect is applied, even when a side collision load is input from the outside in the vehicle width direction to one side sill in the vehicle width direction, the load is transmitted to the side sill on the opposite side via the cross member, allowing for high-efficiency energy absorption.

[0018] In the vehicle body frame structure according to the above aspect, a configuration may be adopted in which a battery is disposed in the floor portion, and the battery is fixed to the side sill.

[0019] In a vehicle to which the body frame structure according to the above aspect is applied, the battery is fixed to the highly rigid side sill, so the battery is securely held in place even if vibrations are applied while the vehicle is traveling, etc. Furthermore, in the above vehicle, even if a side collision load is input to the side sill as described above, the reinforcing member efficiently absorbs energy and transmits the load to the cross member, so damage to the battery in the event of a side collision can be suppressed.

[0020] In the vehicle body frame structure relating to the above aspect, the reinforcing member may be configured to be composed of three plate members that extend in the first direction and are bent and fixed to each other.

[0021] In a vehicle to which the body frame structure according to the above aspect is applied, the reinforcing member is configured using three plate members, so the reinforcing member can be formed using a simpler manufacturing process than when the reinforcing member is integrally formed by casting, etc. Furthermore, when changing vehicle models or design changes, the reinforcing member can be formed while changing its shape more flexibly than when the reinforcing member is formed by casting, etc.

[0022] In the vehicle body frame structure according to the above aspect, the three plate members may be composed of a first plate member, a second plate member, and a third plate member arranged from one side to the other side in the third direction, the first plate member and the third plate member constituting the pair of second cell walls and the pair of third cell walls in each of the plurality of cells, and the second plate member constituting the pair of first cell walls in each of the plurality of cells.

[0023] In a vehicle to which the body frame structure according to the above aspect is applied, each first cell wall in a plurality of cells is configured from a second plate member, and therefore, the curved shape of the second plate member can be used to realize a reinforcing member having an optimal shape while taking into account the absorption characteristics of collision energy. [Effects of the Invention]

[0024] In a vehicle having the body frame structure according to each of the above aspects, high collision energy absorption characteristics can be achieved while suppressing increases in weight and manufacturing costs. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a plan view showing a partial configuration of a vehicle to which a vehicle body frame structure according to an embodiment of the present invention is applied. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view showing the cross section III-III of FIG. 2. [Figure 4] FIG. 2 is an exploded perspective view showing the configuration of a reinforcing member. [Figure 5] FIG. 3 is a cross-sectional view showing a partial configuration of a reinforcing member. [Figure 6] FIG. 4 is a cross-sectional view showing the positional relationship between a reinforcing member and a cross member. [Figure 7] 1(a) is a cross-sectional view showing a partial configuration of a reinforcing member in a body frame structure according to a first modified example, and FIG. 1(b) is a cross-sectional view showing a partial configuration of a reinforcing member in a body frame structure according to a second modified example. [Figure 8]1A is a cross-sectional view showing a partial configuration of a reinforcing member used in a vehicle body frame structure according to the prior art, and FIG. 1B is a cross-sectional view showing a partial configuration of another reinforcing member that is envisioned from the prior art. DETAILED DESCRIPTION OF THE INVENTION

[0026] 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.

[0027] 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."

[0028] [Embodiment] 1. Vehicle 1 Configuration The configuration of a vehicle 1 to which a vehicle body frame structure according to this embodiment is applied will be described with reference to Fig. 1. Note that Fig. 1 shows only a portion of the configuration of the vehicle 1, and does not show the powertrain or the like.

[0029] 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 (framework members) 10, multiple cross members 11, and a battery 12 are arranged in the floor section 11b.

[0030] A 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, respectively. A plurality of cross members 11 each extend in the vehicle width direction and are fixed to the side sills 10. The battery 12 transmits and receives electric power to and from a powertrain (not shown).

[0031] The battery 12 includes a battery cell made up of a lithium ion battery, a nickel-metal hydride battery, or the like, and a battery housing that houses the battery cell.

[0032] 2. Internal structure of side sill 10 The internal structure of the side sill 10 will be described with reference to Figures 2 and 3. Note that Figures 2 and 3 only show the right side sill 10 of the pair of side sills 10, but the left side sill 10 has the same internal structure as the right side sill 10, except that it is reversed left and right.

[0033] 2, the side sill 10 is configured by fixing a side sill outer 101 and a side sill inner 102, both of which have a hat-shaped cross section. The side sill 10 has a closed cross-sectional structure with a hollow portion 10a inside due to the fixing of the side sill outer 101 and the side sill inner 102.

[0034] The side sill outer 101 and the side sill inner 102 have flange portions 101a, 101b, 102a, and 102b in the vertical direction, respectively. The side sill outer 101 and the side sill inner 102 are fixed together by fixing the upper flange portions 101a, 102a to each other and the lower flange portions 101b, 102b to each other.

[0035] A reinforcing member 103 is housed in the hollow portion 10a of the side sill 10. As shown in Fig. 3, the reinforcing member 103 is configured so that a plurality of closed cross-section cells 103a, 103b are continuous in the front-rear direction. As shown in Fig. 3, the plurality of closed cross-section cells 103a, 103b have axes in the vehicle width direction (a direction perpendicular to the plane of the paper in Fig. 3). That is, the plurality of closed cross-section cells 103a, 103b are each hollow columnar in shape having an axis in the vehicle width direction (second direction) and are formed so as to be continuous in the front-rear direction (first direction).

[0036] Each of the multiple closed cross-sectional cells 103a, 103b has a hexagonal shape. The closed cross-sectional cells 103a and 103b adjacent to each other in the front-rear direction are formed so as to share a cell wall (first cell wall) that extends obliquely relative to the up-down and front-rear directions.

[0037] In this embodiment, each of the closed cross-sectional cells 103a, 103b has a distorted hexagonal shape rather than a regular hexagonal shape. That is, each of the closed cross-sectional cells 103a, 103b has a hexagonal shape in which an ellipse or an oval is inscribed in at least a portion of the cell wall (a hexagonal shape that is not a regular hexagonal shape) rather than a regular hexagonal shape in which a circle is inscribed inside.

[0038] 3. Detailed configuration of the reinforcing member 103 The detailed configuration of the reinforcing member 103 will be described with reference to Figures 2 to 4. Figure 4 is an exploded perspective view showing the detailed configuration of the reinforcing member 103.

[0039] As shown in FIGS. 3 and 4, the reinforcing member 103 is formed by fixing together four plate members 104 to 107, including an upper plate member 104, a middle plate member 105, and a lower plate member 106. As shown in FIG. 4, the upper plate member 104 is integrally formed with a plurality of upper wall portions 104a, a plurality of lower wall portions 104b, and a plurality of inclined wall portions 104c to form a wave-like shape. Each of the plurality of upper wall portions 104a is disposed so as to have a plane perpendicular to the front-rear direction and the up-down direction. Each of the plurality of lower wall portions 104b is disposed at a height position lower than the upper wall portion 104a so as to have a plane parallel to the upper wall portion 104a. Each of the plurality of inclined wall portions 104c is disposed so as to connect a front-rear edge of the upper wall portion 104a to a front-rear edge of the lower wall portion 104b.

[0040] A through-hole 104d is formed in the upper wall portion 104a of the upper plate member 104. The through-hole 104d is a hole through which a welding rod is inserted when the middle plate member 105 and the lower plate member 106 are fixed by welding.

[0041] The middle plate member 105 is integrally formed with a plurality of upper wall portions 105a, a plurality of lower wall portions 105b, and a plurality of inclined wall portions 105c to have a wave-like shape. The middle plate member 105 is formed so that its height in the vertical direction is greater than that of the upper plate member 104.

[0042] Each of the plurality of upper wall portions 105a is disposed so as to have a plane parallel to the upper wall portion 104a and the lower wall portion 104b of the upper plate member 104. Each of the plurality of lower wall portions 105b is disposed so as to have a plane parallel to the upper wall portion 105a at a height position lower than the upper wall portion 105a. Each of the plurality of inclined wall portions 105c is disposed so as to connect a front-rear edge of the upper wall portion 105a to a front-rear edge of the lower wall portion 105b.

[0043] The middle plate member 105 is formed so that the difference in height between the upper wall portion 105a and the lower wall portion 105b in the up-down direction is greater than that of the upper plate member 104. Therefore, the height dimension of the inclined wall portion 105c of the middle plate member 105 is greater than the height dimension of the inclined wall portion 104c of the upper plate member 104.

[0044] The lower plate member 106 is integrally formed to have a plurality of upper wall portions 106a, a plurality of lower wall portions 106b, a plurality of inclined wall portions 106c, and a flange portion 106d. The lower plate member 106 is also formed to have a wave-like shape with the plurality of upper wall portions 106a, the plurality of lower wall portions 106b, and the plurality of inclined wall portions 106c. The lower plate member 106 is formed so that its height in the vertical direction is approximately the same as that of the upper plate member 104.

[0045] Each of the upper wall portions 106a is disposed so as to have a plane parallel to the upper wall portion 105a and the lower wall portion 105b of the middle plate member 105. Each of the lower wall portions 106b is disposed so as to have a plane parallel to the upper wall portion 106a at a height position lower than the upper wall portion 106a. Each of the inclined wall portions 106c is disposed so as to connect the front-rear edge of the upper wall portion 106a to the front-rear edge of the lower wall portion 106b. The flange portion 106d is formed so as to hang down from the height position where the lower wall portion 106b is provided, and has a main surface facing rightward. The flange portion 106d of the lower plate member 106 is formed so as to be in surface contact with the inner wall surface 101c of the side sill outer 101 shown in FIG. 2 and is fixed to the inner wall surface 101c by welding.

[0046] The bracket 107 is a plate member in which a horizontal wall portion 107a and a vertical wall portion 107b are integrally formed, and has an overall angular shape. The horizontal wall portion 107a is welded and fixed to the upper wall portion 104a of the upper plate member 104. The vertical wall portion 107b is provided to stand upward from the horizontal wall portion 107a, and is sandwiched between the upper flange portion 101a of the side sill outer member 101 and the upper flange portion 102a of the side sill inner member 102 shown in FIG. 2, and in this state is welded and fixed to the upper flange portions 101a, 102a.

[0047] 4. Shape of the closed cross-section cells 103a and 103b The shapes of the closed cross-sectional cells 103a and 103b in the reinforcing member 103 will be described with reference to Fig. 5. Note that the following will describe the shape of the closed cross-sectional cell 103a, and will not describe the shape of the closed cross-sectional cell 103b. However, the closed cross-sectional cell 103b has the same configuration as the closed cross-sectional cell 103a, except that it is upside down relative to the closed cross-sectional cell 103a.

[0048] As described above, the reinforcing member 103 is formed by combining three plate members 104 to 106, each extending in the vehicle longitudinal direction and having been bent. As shown in Fig. 5, the lower wall portion 104b of the upper plate member 104 and the upper wall portion 105a of the middle plate member 105 are fixed by welding. Furthermore, the lower wall portion 105b of the middle plate member 105 and the upper wall portion 106a of the lower plate member 106 are fixed by welding. By fixing the three plate members 104 to 106 in this manner, the closed cross-sectional cells 103a and 103b of the reinforcing member 103 are formed.

[0049] In the closed cross-section cell 103a, an internal space having a hexagonal cross-section is surrounded by six cell walls 103c to 103h. The upper cell wall 103c is formed by overlapping the lower wall portion 104b of the upper plate member 104 and the upper wall portion 105a of the middle plate member 105. The upper diagonal cell walls 103d and 103h are formed by the diagonal wall portion 105c of the middle plate member 105 and are configured to hang diagonally downward from each edge of the upper cell wall 103c in the front-to-rear direction. The upper diagonal cell walls 103d and 103h are cell walls shared by the closed cross-section cells 103a and 103b adjacent in the front-to-rear direction, and are a pair of first cell walls. In other words, in the reinforcing member 103, the multiple closed cross-section cells 103a and 103b are configured to be continuous, sharing the upper diagonal cell walls 103d and 103h.

[0050] The lower diagonal cell walls 103e and 103g are formed by the diagonal wall portion 106c of the lower plate member 106 and are configured to hang diagonally downward from the lower edges of the upper diagonal cell walls 103d and 103h. The lower cell wall 103f is formed by the lower wall portion 106b of the lower plate member 106. The lower cell wall 103f faces the upper cell wall 103c in a parallel state and is configured to connect the lower edges of the lower diagonal cell walls 103e and 103g. In this embodiment, the lower diagonal cell walls 103e and 103g are third cell walls.

[0051] The side lengths of the upper diagonal cell walls 103d and 103h (side lengths in the cross section shown in FIG. 5) are Ld and Lh. The side lengths of the lower diagonal cell walls 103e and 103g (side lengths in the cross section shown in FIG. 5) are Le and Lg. In this case, the closed cross-sectional cells 103a and 103b are configured so that the side lengths Ld and Lh are longer than the side lengths Le and Lg, respectively. As a result, the closed cross-sectional cells 103a and 103b have a distorted hexagonal shape rather than a regular hexagonal shape.

[0052] 5. Vertical positional relationship between the reinforcing member 103 and the cross member 11 The vertical positional relationship between the reinforcing member 103 and the cross member 11 will be described with reference to Fig. 6. Note that Fig. 6 shows the reinforcing member 103 housed in the side sill 10 on the right side in the vehicle width direction as an example, but the reinforcing member 103 housed in the side sill 10 on the left side in the vehicle width direction is also disposed so as to satisfy the same vertical positional relationship as shown in Fig. 6.

[0053] 6, a cross member 11 and a battery 12 are fixed to the outer wall surface of a side sill inner 102 of the side sill 10. In addition, a floor panel 13 is also fixed to the outer wall surface of the side sill inner 102.

[0054] The cross member 11 is disposed below the floor panel 13 and above the battery 12. The area in which the cross member 11 is disposed in the vertical direction is designated A11, and the area in which the reinforcing member 103 is disposed in the vertical direction is designated A103. In this case, when the cross member 11 and the reinforcing member 103 are viewed from the side in one direction in the vehicle width direction, the area A103 overlaps with the area A11. That is, in this embodiment, the reinforcing member 103 is disposed in an area that overlaps with the cross member 11 in a side view from one direction in the vehicle width direction.

[0055] 6.Effects In the vehicle 1 to which the vehicle body frame structure according to this embodiment is applied, each of the closed cross-sectional cells 103a, 103b is formed so that the side lengths Ld, Lh of the pair of upper diagonal cell walls (first cell walls) 103d, 103h are longer than the side lengths Le, Lg of the lower diagonal cell walls 103e, 103g. This allows the closed cross-sectional cells 103a, 103b to be continuous in the front-rear direction (first direction) while ensuring a larger closed cross-sectional area than when multiple regular hexagonal closed cross-sectional cells are formed. Therefore, the vehicle 1 can achieve high collision energy absorption characteristics when a collision load (side impact load) is input to the side sill 10 from the outside in the vehicle width direction while suppressing increases in weight and manufacturing costs compared to when the configuration shown in FIG. 8(b) is adopted.

[0056] In addition, in the vehicle 1 to which the vehicle body frame structure according to this embodiment is applied, the closed cross-section of each of the closed cross-section cells 103a, 103b is hexagonal, but the upper diagonal cell wall 103d is not parallel to the lower diagonal cell wall 103g, and the upper diagonal cell wall 103h is not parallel to the lower diagonal cell wall 103e. In other words, the closed cross-section cells 103a, 103b, as shown in FIG. 5 and other figures, do not have a circular inscribed circle, but are configured in a shape inscribed with an ellipse. Therefore, in this embodiment, it is possible to connect multiple closed cross-section cells 103a, 103b in the longitudinal direction while ensuring a larger cross-sectional area of ​​the hexagonal closed cross-section cells 103a, 103b compared to a case in which regular hexagonal cell structures are connected as shown in FIG. 8(b).

[0057] Furthermore, in the vehicle 1 to which the body frame structure according to this embodiment is applied, the reinforcing member 103 is arranged in an area that overlaps with the cross member 11 in a side view, so that when a collision load is input from the side of the vehicle 1 to the side sill 10, which is a frame member, the load is transmitted with high efficiency to the cross member 11 via the reinforcing member 103. Therefore, in the vehicle 1, even when a side collision load is input to one side sill 10 in the vehicle width direction, the load is transmitted to the side sill 10 on the opposite side via the cross member 11, allowing for highly efficient energy absorption.

[0058] Furthermore, in the vehicle 1 to which the body frame structure according to this embodiment is applied, the battery 12 is fixed to the side sill 10, which has high rigidity, so the battery 12 is securely held even if vibrations are applied while the vehicle 1 is traveling. Furthermore, in the vehicle 1, even if a side collision load is input to the side sill 10 as described above, the reinforcing member 103 efficiently absorbs energy and transmits the load to the cross member 11, so damage to the battery 12 in the event of a side collision can be suppressed.

[0059] Furthermore, in the vehicle 1 to which the body frame structure according to this embodiment is applied, the reinforcing member 103 is configured to include three plate members 104 to 106, so it is possible to form the reinforcing member 103 through a simpler manufacturing process than when the reinforcing member 103 is integrally formed by casting or the like. Furthermore, when changing vehicle models or design changes, the reinforcing member 103 can be formed while changing its shape more flexibly than when the reinforcing member 103 is formed by casting or the like.

[0060] Furthermore, in the vehicle 1 to which the body frame structure of this embodiment is applied, each upper diagonal cell wall 103d, 103h in the multiple closed cross-section cells 103a, 103b is configured from a middle plate member (second plate member) 105, and therefore, the curved shape of the middle plate member 105 makes it possible to realize a configuration of a reinforcing member 103 with an optimal shape while taking into account the absorption characteristics of collision energy.

[0061] As described above, the vehicle 1 having the body frame structure according to this embodiment can achieve high collision energy absorption characteristics while suppressing increases in weight and manufacturing costs.

[0062] [Variation 1] A vehicle body frame structure according to Modification 1 will be described with reference to Fig. 7(a). The vehicle body frame structure according to this modification is different from the above embodiment in the configuration of the reinforcing member 203 housed in the inner hollow portion 10a of the side sill 10, but the other configurations are the same as those of the above embodiment. The configuration of the reinforcing member 203, which is the difference from the above embodiment, will be described below.

[0063] 7(a), the reinforcing member 203 is configured such that rectangular closed cross-section cells 203a, 203b are continuously aligned in the front-rear direction with adjacent closed cross-section cells 203a, 203b sharing a cell wall in the front-rear direction. Specifically, the reinforcing member 203 is configured to include three plate members 204-205. Of these, the upper plate member 204 and the lower plate member 206 are arranged to face each other and both have a flat plate shape.

[0064] On the other hand, the middle plate member 205 is bent in a wave shape, similar to the middle plate member 105 in the above embodiment.

[0065] In the closed cross-section cells 203a and 203b, an internal space having a quadrangular (trapezoidal) cross section is surrounded by four cell walls 203c to 203f.

[0066] In the closed cross-section cell 203a, the upper cell wall 203c is formed by overlapping a part of the upper plate member 204 and the bent upper wall portion of the middle plate member 205. On the other hand, in the closed cross-section cell 203b, the upper cell wall 203c is formed by a part of the upper plate member 204.

[0067] The oblique cell walls 203d and 203f are formed from part of the middle plate member 205 and are configured to hang obliquely downward from the respective front-rear edges of the upper cell wall 203c. The oblique cell walls 203d and 203f are cell walls shared by the closed cross-section cells 203a and 203b adjacent in the front-rear direction, and are a pair of first cell walls.

[0068] In the closed cross-section cell 203a, the lower cell wall 203e is formed by a part of the lower plate member 206 and is configured to be parallel to the upper cell wall 203c. On the other hand, in the closed cross-section cell 203b, the lower cell wall 203e is formed by overlapping a part of the lower plate member 206 and the bent lower wall portion of the middle plate member 205.

[0069] In the closed cross-sectional cells 203a and 203b, the diagonal cell walls 203d and 203f are arranged not parallel to each other, that is, each of the closed cross-sectional cells 203a and 203b has a trapezoidal cross-sectional shape rather than a square shape.

[0070] The side length of the oblique cell wall 203d (the side length in the cross section shown in FIG. 7(a)) is defined as L2d. The side length of the upper cell wall 203c (the side length in the cross section shown in FIG. 7(a)) is defined as L2c. In this case, the closed cross-sectional cells 203a and 203b are configured so that the side length L2d is longer than the side length L2c.

[0071] The same effects as those of the above embodiment can be obtained in a vehicle to which the body frame structure of this modified example is applied. That is, this modified example differs from the above embodiment in that the closed cross-section cells 203a, 203b have a quadrangle (n=4), but is otherwise the same as the above embodiment. The closed cross-section cells 203a, 203b are configured so that the length L2d of the cell walls (diagonal cell walls) 203d, 203f shared by adjacent closed cross-section cells 203a, 203b in the longitudinal direction of the vehicle is longer than the length L2c of one cell wall (upper cell wall) 203c excluding the diagonal cell walls 203d, 203f in the closed cross-section cells 203a, 203b. Therefore, the same effects as those of the above embodiment can be obtained in a vehicle to which the body frame structure of this modified example is applied.

[0072] [Variation 2] The vehicle body frame structure according to Modification 2 will be described with reference to Fig. 7(b). Note that the vehicle body frame structure according to this modification differs from the above embodiment and Modification 1 in the configuration of the reinforcing member 303 housed in the inner hollow portion 10a of the side sill 10, but the other configurations are the same as those of the above embodiment and Modification 1. Below, the configuration of the reinforcing member 303, which is the difference from the above embodiment and Modification 1, will be described.

[0073] 7(b), the reinforcing member 303 is configured such that octagonal closed cross-section cells 303a, 303b are continuous in the front-rear direction with the cell walls shared by adjacent closed cross-section cells 303a, 303b in the front-rear direction. Specifically, the reinforcing member 303 is configured to include three plate members 304-305. Of these, each of the plate members 304-306 is bent to form a wave shape in the up-down direction, similar to each of the plate members 104-106 in the above embodiment.

[0074] In the closed cross-section cells 303a and 303b, the internal space having an octagonal cross section is surrounded by eight cell walls 303c to 303j.

[0075] In the closed cross-section cell 303a, the upper cell wall 303c and the upper diagonal cell walls 303d and 303j are formed from a part of the upper plate member 304. On the other hand, in the closed cross-section cell 303b, the upper cell wall 303c and the upper diagonal cell walls 303d and 303j are formed by overlapping a part of the upper plate member 304 and a part of the middle plate member 305.

[0076] In the closed cross-section cells 303a, 303b, the vertical cell walls 303e, 303i are formed by part of the middle plate member 305 and are configured to hang down from the lower edges of the upper diagonal cell walls 303d, 303j. The vertical cell walls 303e, 303i are cell walls shared by the closed cross-section cells 303a, 303b adjacent in the front-to-rear direction, and are a pair of first cell walls.

[0077] In the closed cross-section cell 303a, the lower cell wall 303g and the lower diagonal cell walls 303f, 303h are formed by overlapping a part of the lower plate member 306 and a part of the middle plate member 305. On the other hand, in the closed cross-section cell 303b, the lower cell wall 303g and the lower diagonal cell walls 303f, 303h are formed by a part of the lower plate member 306.

[0078] In the closed cross-sectional cells 303a, 303b, the vertical cell walls 303e and 303i are arranged parallel to and facing each other. However, each of the closed cross-sectional cells 303a, 303b is not a regular octagon, and the length L3e of the vertical cell walls 303e, 303i is longer than the lengths of at least some of the other cell walls 303c, 303d, 303f-303h, and 303j. Specifically, the side length of the vertical cell walls 303e, 303i (the side length in the cross section shown in FIG. 7(b)) is defined as L3e. Furthermore, the side length of the lower oblique cell wall 303f (the side length in the cross section shown in FIG. 7(b)) is defined as L3f. In this case, the closed cross-sectional cells 303a, 303b are configured such that the side length L3e is longer than the side length L3f.

[0079] A vehicle to which the body frame structure according to this modification is applied can also achieve the same effects as those of the above embodiment and the above modification 1. That is, this modification differs from the above embodiment and the above modification 1 in that the closed cross-sectional cells 303a, 303b have an octagonal shape (n=8), but is otherwise the same as the above embodiment and the above modification 1. The closed cross-sectional cells 303a, 303b are configured so that the length L3e of the cell walls (vertical cell walls) 303e, 303i shared by adjacent closed cross-sectional cells 303a, 303b in the longitudinal direction of the vehicle is longer than the length L3f of at least one cell wall (downward oblique cell wall) 303f other than the vertical cell walls 303e, 303i in the closed cross-sectional cells 303a, 303b. Therefore, a vehicle to which the body frame structure according to this modification is applied can also achieve the same effects as those of the above embodiment and the above modification 1.

[0080] [Other variations] In the above embodiment, a reinforcing member 103 having a plurality of closed cross-sectional cells 103a, 103b each having a hexagonal cross-sectional shape is used, in the above modification 1, a reinforcing member 203 having a plurality of closed cross-sectional cells 203a, 203b each having a quadrangular cross-sectional shape is used, and in the above modification 2, a reinforcing member 303 having a plurality of closed cross-sectional cells 303a, 303b each having an octagonal cross-sectional shape is used, but the present invention is not limited to this. The cross-sectional shape of the closed cross-sectional cells may be a decagon, a dodecagon, or more sides as long as it is an n-gon (n: an even number of 4 or more).

[0081] In addition, in the above embodiment and modified examples 1 and 2, the reinforcing members 103, 203, and 303 are housed in the hollow portion 10a of the side sill 10, but the present invention is not limited to this. For example, the configuration of the present invention may be adopted as a reinforcing member housed in the hollow portion of a pillar (front pillar, center pillar, or rear pillar).

[0082] In the above embodiment and modified example 2, the reinforcing members 103 and 303 are constructed by fixing three bent plate members 104-106 and 304-306 together, and the plate members 104-106 and 304-306 are overlapped so that the bent corners of the plate members 104-106 and 304-306 match, but the present invention is not limited to this. Misalignment between the bent corners of the plate members may occur in the front-to-rear or up-to-down directions of the vehicle within the range of manufacturing tolerances.

[0083] Furthermore, in the above embodiment and the above variants 1 and 2, the reinforcing members 103, 203, and 303 are constructed by fixing together a plurality of plate members, including three plate members 104-106, 204-206, and 304-306. However, in the present invention, it is also possible to employ reinforcing members in which at least a portion is integrally formed by casting.

[0084] In addition, in the above embodiment and modified examples 1 and 2, the reinforcing members 103, 203, 303 are arranged in an area overlapping with the cross member 11 in a side view from the side of the vehicle 1 (one side in the vehicle width direction), but in the present invention, the reinforcing members do not necessarily have to be arranged in an area overlapping with the cross member. In a side view from one side in the vehicle width direction, the reinforcing members may be arranged in a position that does not overlap with the cross member but is offset in the vertical direction.

[0085] In addition, in the above embodiment and the first and second modifications, a configuration is adopted in which the housing of the battery 12 is directly fixed to the side sill 10, but in the present invention, the battery does not have to be fixed to the side sill. For example, the battery may be fixed to a cross member or a floor panel.

[0086] Furthermore, in the above-mentioned variant example 1, of the three plate members 204 to 206 constituting the reinforcing member 203, plate members 204 and 206 are not bent and have a flat plate shape, but in the present invention, the upper plate member 204 and the lower plate member 206 may also be bent so as to have a wave-like shape in the vertical direction. [Explanation of symbols]

[0087] 1 vehicle 1b Floor section 10 Side sill (framework) 11 Cross member 101 Side sill outer 102 Side sill inner 103,203,303 Reinforcement members 103a, 103b, 203a, 203b, 303a, 303b Closed cross-section cells (cells) 103d, 103h Upper diagonal cell wall (first cell wall) 103e,103g,303d,303f,303h,303j Lower diagonal cell wall 104, 204, 304 Upper plate member 105, 205, 305 Middle plate members 106, 206, 306 Lower plate member 203c Upper cell wall 203d, 203f Diagonal cell wall (first cell wall) 303e, 303i Vertical cell wall (first cell wall)

Claims

1. a frame member that forms a frame of a vehicle body, the frame member having a hollow portion on its inside and extending in a first direction; a reinforcing member that is housed in the hollow portion of the framework member, the reinforcing member having a plurality of cells that are formed into a hollow columnar shape by a plurality of cell walls and have an axis in a second direction that intersects the first direction, and the plurality of cells are formed so as to be continuously aligned in the first direction; Equipped with the plurality of cells in the reinforcing member each have an n-sided polygon (n: an even number of 4 or more) in a cross section perpendicular to the second direction, and the cells adjacent to each other in the first direction are formed so as to share the cell wall; When the cell wall shared by the adjacent cells is defined as a first cell wall, each of the plurality of cells is formed such that a side length of the first cell wall in the orthogonal cross section is longer than a side length of at least one of the other cell walls forming the cell. Vehicle body frame structure.

2. In the orthogonal cross section, when a direction orthogonal to the first direction is defined as a third direction, Each of the plurality of cells has a hexagonal shape in the orthogonal cross section, and includes a pair of second cell walls extending in the first direction and facing each other in the third direction, and a pair of third cell walls connecting an end side in the first direction of one of the pair of second cell walls to each of end sides in the third direction of the pair of first cell walls, Each of the plurality of cells is formed such that a side length of the first cell wall is longer than a side length of the third cell wall. The vehicle body frame structure according to claim 1.

3. the framework member is a side sill that is disposed on the outer side of a floor portion of the vehicle in a vehicle width direction and is formed to extend in a front-rear direction of the vehicle, a cross member is disposed on a floor portion of the vehicle, one end of which is connected to the side sill and which extends in a vehicle width direction; In a side view from the side of the vehicle, the reinforcing member is arranged in an area overlapping with the cross member. The vehicle body frame structure according to claim 2.

4. A battery is disposed in the floor portion, The battery is fixed to the side sill. The vehicle body frame structure according to claim 3.

5. The reinforcing member is configured by three plate members each extending in the first direction and being bent and fixed to each other.

5. A vehicle body frame structure according to claim 2.

6. the three plate members are configured by a first plate member, a second plate member, and a third plate member that are arranged from one side to the other side in the third direction, the first plate member and the third plate member constitute the pair of second cell walls and the pair of third cell walls in each of the plurality of cells, The second plate member constitutes the pair of first cell walls in each of the plurality of cells. The vehicle body frame structure according to claim 5.

Images