Vehicle side sill reinforcement structure

Abstract

To increase an absorption quantity of impact energy in a side sill reinforcement structure for a vehicle.SOLUTION: A side sill reinforcement structure for vehicles includes: a side sill 20 extending in a vehicle fore-and-aft direction in a lateral part of a vehicle; and a reinforcement member 40 that reinforces the side sill 20. The reinforcement member 40 has plural closed cross-sectional parts 40a juxtaposed in a vehicle width direction on a cross section vertical to the vehicle fore-and-aft direction. The closed cross-sectional parts 40a include a first closed cross-sectional part 41 disposed outermost in the vehicle width direction. The first closed cross-sectional part 41 includes a first upper wall 41a and first lower wall 41b opposed to each other and separated from each other in a vehicle vertical direction, and a first lateral wall 41c connecting outside edges in the vehicle width direction of the first upper wall 41a and first lower wall 41b respectively. A thickness of the first lateral wall 41c is larger than that of the first upper wall 41a or outermost lower wall 41b.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a side sill reinforcement structure for a vehicle. [Background technology]

[0002] Vehicles are required to have high collision safety performance from the viewpoint of protecting the passenger compartment. In particular, side collisions (hereinafter also referred to as lateral impacts) tend to inflict strong impacts on the passenger compartment, so high impact absorption performance is required for side collisions. In other words, when the vehicle spins and an object such as a pole hits the side of the vehicle, it is necessary to absorb the impact energy and protect the passenger compartment.

[0003] For example, Patent Document 1 discloses a vehicle underbody structure that suppresses deformation of the vehicle interior and improves safety performance in side collisions. In this vehicle underbody structure, a reinforcing member is placed under a frame member located on the side of the vehicle body, known as a rocker or side sill, and the reinforcing member absorbs impact energy during a side collision. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-90020 Summary of the Invention [Problem to be solved by the invention]

[0005] In a side collision of a vehicle, the impact load tends to increase as the deformation (displacement) of the reinforcing member in the vehicle width direction increases. Therefore, if the shape and thickness of the reinforcing member in the vehicle width direction are constant as in Patent Document 1, the reinforcing member cannot withstand a large impact load in the initial stage of deformation (stage where displacement is small), and the amount of impact energy absorption decreases.

[0006] An object of the present invention is to improve the amount of impact energy absorbed in a vehicle side sill reinforcement structure. [Means for solving the problem]

[0007] The present invention provides a vehicle body comprising a side sill extending in a vehicle longitudinal direction at a side portion of the vehicle, and a reinforcing member for reinforcing the side sill, wherein the reinforcing member has a plurality of closed cross-sectional portions that are continuous in a vehicle width direction in a cross section perpendicular to the vehicle longitudinal direction, the plurality of closed cross-sectional portions including an outermost closed cross-sectional portion that is disposed outermost in the vehicle width direction, the outermost closed cross-sectional portion including an outermost upper wall and an outermost lower wall that are disposed opposite to each other and spaced apart in the vehicle vertical direction, and an outermost wall that connects outer ends of the outermost upper wall and the outermost lower wall in the vehicle width direction, and the thickness of the outermost wall is and To provide a vehicle side sill reinforcing structure having a thickness greater than that of the outermost lower wall.

[0008] According to this configuration, the side sill is reinforced by the reinforcing member, and the amount of impact energy absorbed during a side collision (hereinafter simply referred to as energy absorption amount) can be improved. Specifically, when a plurality of closed cross-sectional portions connected in the vehicle width direction are provided as in the above configuration, during a side collision, each of the plurality of closed cross-sectional portions will be crushed in order from the outside to the inside in the vehicle width direction. In particular, the outermost closed cross-sectional portion of the plurality of closed cross-sectional portions is the portion that will be crushed first. Furthermore, the outermost wall of the outermost closed cross-sectional portion is disposed outermost in the vehicle width direction, and is the portion that will be subjected to impact first. In the above configuration, the thickness of the outermost wall is and Because the thickness of the outermost lower wall is greater than that of the outermost wall, the impact load during the initial deformation stage of the reinforcing member can be increased. Furthermore, if the outermost wall, which receives the impact first, breaks, the amount of energy absorption decreases. Therefore, the outermost wall is relatively thick to suppress breakage. Therefore, the amount of energy absorption can be improved compared to when a reinforcing member of uniform thickness is used. Furthermore, this reduces the variation in impact load according to displacement and promotes the equalization of impact load, thereby improving the energy absorption efficiency compared to when a reinforcing member of uniform thickness is used.

[0009] The thickness of the outermost wall is andThe thickness may be 1.4 times or less the thickness of the outermost lower wall.

[0010] According to this configuration, it is possible to improve the energy absorption amount while suppressing excessive changes in the thickness of the reinforcing member. and It was confirmed that gradually increasing the thickness of the outermost lower wall to 1.0 to 1.4 times gradually improved the energy absorption capacity. However, even if the thickness was increased beyond 1.4 times, there was no significant change in the energy absorption capacity (or energy absorption efficiency), and in fact, it was confirmed that if the thickness was increased too much, the energy absorption capacity (or energy absorption efficiency) may decrease.

[0011] The thickness of the outermost wall is and The thickness of the outermost wall may be 1.2 times or more the thickness of the outermost lower wall. and The thickness may be 1.3 times or more the thickness of the outermost lower wall.

[0012] According to this configuration, the amount of energy absorption can be improved. and It was confirmed that when the thickness was gradually increased relative to the thickness of the outermost lower wall, the degree of increase in energy absorption was small up to 1 to 1.2 times, and the degree of increase in energy absorption became larger from 1.2 times or more, and the degree of increase in energy absorption or energy absorption efficiency became even greater from 1.3 times or more.

[0013] The plurality of closed cross-sectional portions may include an innermost closed cross-sectional portion disposed at the innermost side in the vehicle width direction, each of the plurality of closed cross-sectional portions including an upper wall and a lower wall disposed opposite to each other and spaced apart in the vehicle up-down direction, and a side wall connecting outer ends of the upper wall and the lower wall in the vehicle width direction, wherein thicknesses of the side walls of each of the plurality of closed cross-sectional portions excluding the innermost closed cross-sectional portion may decrease sequentially from the outer side to the inner side in the vehicle width direction. Also, thicknesses of the upper walls of each of the plurality of closed cross-sectional portions excluding the innermost closed cross-sectional portion may decrease sequentially from the outer side to the inner side in the vehicle width direction, and thicknesses of the lower walls of each of the plurality of closed cross-sectional portions excluding the innermost closed cross-sectional portion may decrease sequentially from the outer side to the inner side in the vehicle width direction.

[0014] With these configurations, the deformation strength of the reinforcing members gradually decreases from the outer side to the inner side in the vehicle width direction as the deformation area expands in the longitudinal direction of the vehicle as the side collision progresses, which makes it possible to even out the impact load that tends to increase as the deformation progresses, thereby improving energy absorption efficiency.

[0015] The reinforcing member may be disposed inside the side sill.

[0016] According to this configuration, the internal space of the reinforcing member can be effectively utilized, and the vehicle side sill reinforcing structure can be made smaller.

[0017] The reinforcing member may be disposed adjacent to the side sill.

[0018] This configuration allows the side sill to be reinforced easily. Also, "adjacent to the side sill" means that the part is located close to the side sill, regardless of whether it is located above, below, to the left, or to the right in a cross section of the side sill perpendicular to the vehicle's fore-and-aft direction.

[0019] The reinforcing member may be an extruded member made of an aluminum alloy.

[0020] According to this configuration, since an extruded material made of an aluminum alloy is used as the reinforcing member, the thickness of a portion of the reinforcing member can be easily changed. [Effects of the Invention]

[0021] According to the present invention, it is possible to improve the amount of impact energy absorption in a vehicle side sill reinforcement structure. [Brief explanation of the drawings]

[0022] [Figure 1] Side view of a vehicle. [Figure 2] 1 is a cross-sectional view of a vehicle side sill reinforcement structure according to a first embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view of a reinforcing member according to the first embodiment. [Figure 4] Graph showing energy absorption efficiency. [Figure 5] FIG. 10 is a plan view of a reinforcing member as an analytical model. [Figure 6] FIG. 10 is a front view of a reinforcing member as an analysis model. [Figure 7] Graph showing the analysis results. [Figure 8] FIG. 6 is a cross-sectional view of a reinforcing member of a vehicle side sill reinforcing structure according to a second embodiment. [Figure 9] FIG. 10 is a cross-sectional view of a reinforcing member according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view of a vehicle side sill reinforcement structure according to a third embodiment. [Figure 11] FIG. 10 is a cross-sectional view of a reinforcing member according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle side sill reinforcement structure according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0024] (First embodiment) Referring to FIG. 1, vehicle 1 is a vehicle that travels by driving a motor (not shown) with power supplied from battery 11. Vehicle 1 broadly refers to a vehicle that has a drive battery below the passenger compartment R, and may be, for example, an electric vehicle or a plug-in hybrid vehicle. The type of vehicle is not particularly limited, and may be a passenger car, truck, work vehicle, or other mobility vehicle. Below, the vehicle side sill reinforcement structure of this embodiment will be described using a passenger car-type electric vehicle as an example of vehicle 1 as shown in FIG. 1.

[0025] 1, the front-rear direction of the vehicle 1 is indicated as the X direction, and the up-down direction is indicated as the Z direction. The same notation is used in the subsequent figures, and in Fig. 2 and subsequent figures, the vehicle width direction is indicated as the Y direction.

[0026] The vehicle 1 is equipped with a battery unit 10 mounted on substantially the entire surface under the floor of a passenger compartment R in the center of the vehicle body. The battery unit 10 includes a drive battery 11 and a battery case 12 that houses the battery 11.

[0027] Referring to FIG. 2, the battery case 12 has an upper case 13 and a lower case 14. The upper case 13 has an accommodation portion 13a that is concave upward and a flange portion 13b that is provided around the accommodation portion 13a in a plan view. The lower case 14 has an accommodation portion 14a that is concave downward and a flange portion 14b that is provided around the accommodation portion 14a in a plan view. The flange portions 13b, 14b are bonded together to join the upper case 13 and the lower case 14. The battery 11 is accommodated in an accommodation space S1 that is defined by the accommodation portion 13a of the upper case 13 and the accommodation portion 14a of the lower case 14.

[0028] A hollow side sill 20 extending in the longitudinal direction of the vehicle is disposed on the outer side of the battery unit 10 in the vehicle width direction (on the left side in FIG. 2) on the side of the vehicle 1. The side sill 20 is a reinforcing member that constitutes the outer surface of the lower part of the vehicle 1.

[0029] In this embodiment, the side sill 20 has an outer member 21 disposed on the outer side in the vehicle width direction and an inner member 22 disposed on the inner side in the vehicle width direction. The outer member 21 and the inner member 22 are both formed by bending metal sheets into a hat shape and are bonded together to form an interior space S2. The outer member 21 and the inner member 22 may be made of, for example, steel. Alternatively, the outer member 21 and the inner member 22 may be made of, for example, an aluminum alloy.

[0030] A floor panel 30 is disposed above the battery unit 10. The floor panel 30 is a plate material that forms the underside of the passenger compartment R. A cross member 31 extending in the vehicle width direction is disposed above the floor panel 30. Although not shown in detail, multiple cross members 31 are provided at intervals in the fore-and-aft direction of the vehicle.

[0031] A reinforcing member 40 that reinforces the side sill 20 is disposed below the side sill 20. The reinforcing member 40 is disposed adjacent to the side sill 20 and connects the battery unit 10 and the side sill 20. The reinforcing member 40 is made of an extruded material made of, for example, an aluminum alloy.

[0032] The reinforcing member 40 extends in the vehicle longitudinal direction along the side sill 20. In a cross section perpendicular to the vehicle longitudinal direction, the reinforcing member 40 has a plurality of closed cross-sectional portions 40a that are continuous in the vehicle width direction.

[0033] In this embodiment, the multiple closed cross-sectional portions 40a include, in order from the outside in the vehicle width direction, a first closed cross-sectional portion (outermost closed cross-sectional portion) 41, a second closed cross-sectional portion 42, a third closed cross-sectional portion 43, a fourth closed cross-sectional portion 44, and a fifth closed cross-sectional portion (innermost closed cross-sectional portion) 45. The multiple closed cross-sectional portions 40a are rectangular portions of approximately the same size in a cross section perpendicular to the vehicle longitudinal direction.

[0034] Referring to FIG. 3, the first closed cross-sectional portion 41 is disposed at the outermost position in the vehicle width direction among the plurality of closed cross-sectional portions 40a. The first closed cross-sectional portion 41 includes a first upper wall (outermost upper wall) 41a and a first lower wall (outermost lower wall) 41b that extend in the vehicle width direction and are disposed opposite each other and spaced apart in the vehicle up-down direction. The first upper wall 41a is disposed relatively higher, and the first lower wall 41b is disposed relatively lower. In this embodiment, the first upper wall 41a and the first lower wall 41b have the same thickness. However, the first upper wall 41a and the first lower wall 41b may have different thicknesses. The first closed cross-sectional portion 41 also includes a first side wall (outermost wall) 41c that connects the outer ends of the first upper wall 41a and the first lower wall 41b in the vehicle width direction and extends in the vehicle up-down direction.

[0035] The second closed cross-sectional portion 42 is disposed adjacent to the first closed cross-sectional portion 41. The second closed cross-sectional portion 42 includes a second upper wall 42a and a second lower wall 42b that extend in the vehicle width direction and are disposed opposite each other and spaced apart in the vehicle up-down direction. The second upper wall 42a is disposed relatively higher, and the second lower wall 42b is disposed relatively lower. In this embodiment, the second upper wall 42a and the second lower wall 42b have the same thickness. However, the second upper wall 42a and the second lower wall 42b may have different thicknesses. The second closed cross-sectional portion 42 also includes a second side wall 42c that connects outer ends of the second upper wall 42a and the second lower wall 42b in the vehicle width direction and extends in the vehicle up-down direction. The second side wall 42c also connects inner ends of the first upper wall 41a and the first lower wall 41b in the vehicle width direction. That is, the first closed cross-sectional portion 41 and the second closed cross-sectional portion 42 share the second side wall 42c.

[0036] The third closed cross-sectional portion 43 is disposed adjacent to the second closed cross-sectional portion 42. The third closed cross-sectional portion 43 includes a third upper wall 43a and a third lower wall 43b extending in the vehicle width direction and disposed opposite each other and spaced apart in the vehicle up-down direction. The third upper wall 43a is disposed relatively higher, and the third lower wall 43b is disposed relatively lower. In this embodiment, the third upper wall 43a and the third lower wall 43b have the same thickness. However, the third upper wall 43a and the third lower wall 43b may have different thicknesses. The third closed cross-sectional portion 43 also includes a third side wall 43c extending in the vehicle up-down direction and connecting outer ends of the third upper wall 43a and the third lower wall 43b in the vehicle width direction. The third side wall 43c also connects inner ends of the second upper wall 42a and the second lower wall 42b in the vehicle width direction. That is, the second closed cross-sectional portion 42 and the third closed cross-sectional portion 43 share the third side wall 43c.

[0037] The fourth closed cross-sectional portion 44 is disposed adjacent to the third closed cross-sectional portion 43. The fourth closed cross-sectional portion 44 includes a fourth upper wall 44a and a fourth lower wall 44b extending in the vehicle width direction and disposed opposite each other and spaced apart in the vehicle up-down direction. The fourth upper wall 44a is disposed relatively higher, and the fourth lower wall 44b is disposed relatively lower. In this embodiment, the fourth upper wall 44a and the fourth lower wall 44b have the same thickness. However, the fourth upper wall 44a and the fourth lower wall 44b may have different thicknesses. The fourth closed cross-sectional portion 44 also includes a fourth side wall 44c extending in the vehicle up-down direction and connecting outer ends of the fourth upper wall 44a and the fourth lower wall 44b in the vehicle width direction. The fourth side wall 44c also connects inner ends of the third upper wall 43a and the third lower wall 43b in the vehicle width direction. That is, the third closed cross-sectional portion 43 and the fourth closed cross-sectional portion 44 share the fourth side wall 44c.

[0038] The fifth closed cross-sectional portion 45 is located at the innermost position in the vehicle width direction among the multiple closed cross-sectional portions 40a. The fifth closed cross-sectional portion 45 includes a fifth upper wall 45a and a fifth lower wall 45b that extend in the vehicle width direction and are spaced apart from each other in the vehicle up-down direction and opposed to each other. The fifth upper wall 45a is located relatively higher, and the fifth lower wall 45b is located relatively lower. In this embodiment, the fifth upper wall 45a and the fifth lower wall 45b have the same thickness. However, the fifth upper wall 45a and the fifth lower wall 45b may have different thicknesses. The fifth closed cross-sectional portion 45 also includes a fifth side wall 45c that connects the outer ends of the fifth upper wall 45a and the fifth lower wall 45b in the vehicle width direction and extends in the vehicle up-down direction. The fifth closed cross-sectional portion 45 also includes an innermost wall 45d that connects the inner ends of the fifth upper wall 45a and the fifth lower wall 45b in the vehicle width direction and extends in the vehicle up-down direction.

[0039] In this embodiment, the first closed cross-sectional portion 41 has a rectangular closed cross-sectional shape formed by a first upper wall 41a, a first lower wall 41b, a first side wall 41c, and a second side wall 42c. The second closed cross-sectional portion 42 has a rectangular closed cross-sectional shape formed by a second upper wall 42a, a second lower wall 42b, a second side wall 42c, and a third side wall 43c. The third closed cross-sectional portion 43 has a rectangular closed cross-sectional shape formed by a third upper wall 43a, a third lower wall 43b, a third side wall 43c, and a fourth side wall 44c. The fourth closed cross-sectional portion 44 has a rectangular closed cross-sectional shape formed by a fourth upper wall 44a, a fourth lower wall 44b, a fourth side wall 44c, and a fifth side wall 45c. In the fifth closed cross-sectional portion 45, a rectangular closed cross-sectional shape is formed by a fifth upper wall 45a, a fifth lower wall 45b, a fifth side wall 45c, and an innermost wall 45d.

[0040] Referring to FIG. 2, the fifth closed cross-section portion 45 is joined to the battery unit 10 by a bolt 60. The bolt 60 extends in the vehicle vertical direction, passing through the fifth upper wall 45a, the fifth lower wall 45b, the flange portion 13b of the upper case 13, the flange portion 14b of the lower case 14, and the floor panel 30 to join them together. From the perspective of efficient battery replacement, the bolt 60 is preferably inserted from bottom to top and fastened. Furthermore, to ensure high joint strength, it is preferable to use a cylindrical collar 61 that covers the periphery of the bolt 60 to suppress deformation of the fastening portion of the bolt 60.

[0041] The first closed cross-section portion 41 is joined to the side sill 20 by a bolt 70. The bolt 70 extends in the vertical direction of the vehicle, penetrates the first upper wall 41a, the first lower wall 41b, and the outer member 21 of the side sill 20, and terminates in the internal space S2 to join them together. As described above, the bolt 70 is preferably inserted from bottom to top and fastened, and a cylindrical collar 71 that covers the periphery of the bolt 70 is preferably used.

[0042] 3 to 7, the preferred dimensional relationships of the various parts of the reinforcing member 40 in this embodiment will be described.

[0043] Referring to FIG. 3, the thickness ts1 of the first side wall 41c is 1 / 2 times the thickness tu1 of the first upper wall 41a. and It is larger than the thickness tl1 of the first lower wall 41b.

[0044] In the multiple closed cross-sectional portions 40a, the thicknesses ts1 to ts4 of the first to fourth side walls 41c to 44c of the first to fourth closed cross-sectional portions 41 to 44, excluding the fifth closed cross-sectional portion (innermost closed cross-sectional portion) 45, decrease in order from the outer side to the inner side in the vehicle width direction (ts1>ts2>ts3>ts4).

[0045] In the multiple closed cross-sectional portions 40a, thicknesses tu1 to tu4 of the first to fourth upper walls 41a to 44a of the first to fourth closed cross-sectional portions 41 to 44, excluding the fifth closed cross-sectional portion (innermost closed cross-sectional portion) 45, decrease in order from the outer side to the inner side in the vehicle width direction (tu1>tu2>tu3>tu4). Furthermore, the thickness tu5 of the fifth upper wall 45a is greater than the thickness tu4 of the fourth upper wall 45a (tu5>tu4).

[0046] Similarly, in the multiple closed cross-sectional portions 40a, thicknesses tl1 to tl4 of the first to fourth lower walls 41b to 44b of the first to fourth closed cross-sectional portions 41 to 44, excluding the fifth closed cross-sectional portion (innermost closed cross-sectional portion) 45, decrease in order from the outer side to the inner side in the vehicle width direction (tl1>tl2>tl3>tl4). Also, the thickness tl5 of the fifth lower wall 45b is greater than the thickness tl4 of the fourth upper wall 44b (tl5>tl4).

[0047] Furthermore, in order to appropriately define the dimensional relationship in the first closed cross-sectional portion 41, the following analysis was performed to confirm the amount and efficiency of impact energy absorption (hereinafter simply referred to as the energy absorption amount and energy absorption efficiency).

[0048] Referring to FIG. 4, the amount of energy absorption is represented by the area (shaded portion) of a graph showing displacement S (mm) and load P (kN). Displacement S indicates the amount of deformation of the reinforcing member 40 in the vehicle width direction. Load P indicates the impact load received by the reinforcing member 40 during a side collision. Energy absorption efficiency is expressed as the ratio of the area of ​​the shaded portion, which indicates the amount of energy absorption, to the area of ​​a rectangle represented by maximum displacement S1 and maximum load P1. Therefore, energy absorption efficiency can be improved by equalizing load P regardless of displacement S. Analysis confirmed a suitable dimensional relationship that improves energy absorption efficiency. Note that FIG. 4 is a schematic graph for explaining energy absorption efficiency, and does not represent the results of analysis.

[0049] Referring to Figure 5, in the analysis, to simulate a side collision of vehicle 1, a cylindrical pole 2 with a diameter of 254 mm was quasi-statically pressed against reinforcing member 40 inward in the vehicle width direction. The set value for the amount of pressing was 150 mm. A wall 3 was placed inside reinforcing member 40 in the vehicle width direction to restrict movement of reinforcing member 40 in the vehicle width direction. Pole 2 and wall 3 were set as rigid bodies that do not deform.

[0050] Because the reinforcing member 40 has a symmetrical shape in the vehicle longitudinal direction, the reinforcing member 40 was created as a half model with respect to the center line CL in the vehicle longitudinal direction. The length D1 of the half model of the reinforcing member 40 in the vehicle longitudinal direction was set to 600 mm. The length D2 of the reinforcing member 40 in the vehicle width direction was set to 210 mm. Then, with the center of the pole 2 aligned with the center line CL, the pole 2 was moved inward in the vehicle width direction.

[0051] 6, the reinforcing member 40 serving as the analytical model has a sixth closed cross-sectional portion 46 in addition to the first to fifth closed cross-sectional portions 41 to 45. The fifth closed cross-sectional portion 45 has a partition wall 45e that divides the interior thereof along a diagonal line.

[0052] The sixth closed cross-sectional portion 46 is disposed adjacent to and above the fifth closed cross-sectional portion 45 and, like the fifth closed cross-sectional portion 45, is disposed at the innermost position in the vehicle width direction. The sixth closed cross-sectional portion 46 includes a sixth upper wall 46a and a sixth lower wall 46b that extend in the vehicle width direction and are disposed opposite each other and spaced apart in the vehicle up-down direction. The sixth upper wall 46a is disposed relatively higher, and the sixth lower wall 46b is disposed relatively lower. The sixth lower wall 46b represents the same portion as the fifth upper wall 45a, but for convenience, is given a different name and symbol. The sixth closed cross-sectional portion 46 also includes a sixth side wall 46c that connects the outer ends of the sixth upper wall 46a and the sixth lower wall 46b in the vehicle width direction and extends in the vehicle up-down direction. The sixth closed cross-sectional portion 46 also includes an innermost wall 46d that connects the inner ends of the sixth upper wall 46a and the sixth lower wall 46b in the vehicle width direction and extends in the vehicle up-down direction. The innermost wall 46d is continuous with the innermost wall 45d.

[0053] The dimensions were set as follows for the cross section of the analysis model perpendicular to the vehicle longitudinal direction (see Fig. 6).

[0054] The length d1 of the first to fifth closed cross-sectional portions 41 to 45 in the vehicle vertical direction was 45 mm. The total length d2 of the fifth closed cross-sectional portion 45 and the sixth closed cross-sectional portion 46 in the vehicle vertical direction was 80 mm. The total length d3 of the first to fourth closed cross-sectional portions 41 to 44 in the vehicle width direction was 160 mm. The length d4 of the fifth closed cross-sectional portion 45 and the sixth closed cross-sectional portion 46 in the vehicle width direction was 50 mm.

[0055] The second to fifth upper walls 42a to 45a each had a thickness of 5 mm. The second to fifth lower walls 42b to 45b each had a thickness of 5 mm. The second to fourth side walls 42c to 44c each had a thickness of 5 mm. The fifth side wall 45c and the innermost wall 45d each had a thickness of 6 mm. The partition wall 45e had a thickness of 3 mm. The sixth upper wall 46a had a thickness of 3 mm. The sixth side wall 46c and the innermost wall 46d each had a thickness of 6 mm.

[0056] Below Analysis models with different dimensions were prepared, as shown in Cases 1 to 6 in Table 1 below. Specifically, the thickness tu1 of the first upper wall 41a was set to 5 mm, and the thickness ts1 of the first side wall 41c was changed to 5 mm, 6 mm, 6.25 mm, 6.5 mm, 7 mm, and 8 mm. Because the thickness tu1 of the first upper wall 41a and the thickness tl1 of the first lower wall 41b were set to be the same, the thickness tl1 of the first lower wall 41b is not shown. Table 1 also shows the thickness ratio ts1 / tu1 (or ts1 / tl1), which is the value obtained by dividing the thickness ts1 by the thickness tu1. Table 1 also shows the energy absorption amount EA and energy absorption efficiency EAE shown in Figure 4 as analysis results.

[0057] [Table 1]

[0058] 7 is a graph of the energy absorption amount EA in Table 1. The horizontal axis represents the thickness ratio ts1 / tu1 between the first side wall 41c and the first upper wall 41a (i.e., the thickness ratio ts1 / tl1 between the first side wall 41c and the first lower wall 41b), and the vertical axis represents the energy absorption amount EA (kJ).

[0059] As shown in Figure 7, it was confirmed that, in general, the greater the thickness ratio ts1 / tu1, the greater the absorbed energy EA. In particular, it was confirmed that when the thickness ratio ts1 / tu1 is 1.30 or greater, the absorbed energy EA is significantly greater than when the thickness ratio ts1 / tu1 is 1.00. It was also confirmed that when the thickness ratio ts1 / tu1 is in the range of 1.40 to 1.60, the absorbed energy EA decreases. Furthermore, as shown in Table 1, it was confirmed that when the thickness ratio ts1 / tu1 is 1.30 or greater, the energy absorption efficiency EAE is greater than when the thickness ratio ts1 / tu1 is 1.00. It was confirmed that when the thickness ratio ts1 / tu1 is in the range of 1.40 to 1.60, the energy absorption efficiency EAE gradually decreases.

[0060] To summarize the above analysis results, it is preferable that the thickness ts1 of the first side wall 41c is less than the thickness tu1 of the first upper wall 41a. and The thickness ts1 of the first side wall 41c is preferably 1.4 times or less than the thickness tl1 of the first lower wall 41b (ts1≦1.4tu1 or ts1≦1.4tl1). and The thickness tl1 of the first lower wall 41b is 1.2 times or more (ts1≧1.2tu1 and More preferably, the thickness ts1 of the first side wall 41c is less than the thickness tu1 of the first upper wall 41a. and The thickness tl1 of the first lower wall 41b is 1.3 times or more (ts1≧1.3tu1 and ts1 ≥ 1.3tl1).

[0061] The vehicle side sill reinforcement structure of this embodiment provides the following advantages.

[0062] The thickness ts1 of the first side wall 41c is equal to the thickness tu1 of the first upper wall 41a. andSince the thickness ts1 is greater than the thickness tl1 of the first lower wall 41b, the reinforcing member 40 reinforces the side sill 20, thereby improving the amount of energy absorbed EA during a side collision. Specifically, when a plurality of closed cross-sectional portions 40a connected in the vehicle width direction are provided as in this embodiment, each of the plurality of closed cross-sectional portions 40a will be crushed in turn from the outside to the inside in the vehicle width direction during a side collision. In particular, the first closed cross-sectional portion 41 of the plurality of closed cross-sectional portions 40a is the portion that is crushed first. Furthermore, the first side wall 41c of the first closed cross-sectional portion 41 is disposed outermost in the vehicle width direction, and is the portion that receives the impact first. In this embodiment, the thickness ts1 of the first side wall 41 is set equal to the thickness tu1 of the first upper wall 41a. and By making the thickness ts1 of the first bottom wall 41b larger than the thickness tl1, the impact load at the initial stage of deformation of the reinforcing member 40 can be increased. Furthermore, if the first side wall 41c, which receives the impact first, breaks, the energy absorption amount EA decreases. Therefore, by making the thickness ts1 of the first side wall 41c relatively large, breakage is suppressed. Therefore, the energy absorption amount EA can be improved compared to when a reinforcing member of uniform thickness is used. Furthermore, this reduces the variation in the impact load according to the displacement and promotes the equalization of the impact load, thereby improving the energy absorption efficiency EAE compared to when a reinforcing member of uniform thickness is used.

[0063] Preferably, the thickness ts1 of the first side wall 41c is set to tu1 and By setting the thickness tl1 to 1.4 times or less the thickness tl1 of the first lower wall 41b, it is possible to improve the energy absorption amount EA while suppressing excessive changes in the thickness of the reinforcing member 40.

[0064] Furthermore, it is preferable to make the thickness ts1 of the first side wall 41c at least 1.2 times the thickness tu1 of the first upper wall 41a or the thickness tl1 of the first lower wall 41b, and more preferably at least 1.3 times the thickness, thereby further improving the energy absorption amount EA or the energy absorption efficiency EAE.

[0065] Furthermore, the thicknesses ts1 to ts4 of the first to fourth side walls 41c to 44c sequentially decrease from the outer side to the inner side in the vehicle width direction (ts1>ts2>ts3>ts4). Furthermore, the thicknesses tu1 to tu4 of the first to fourth upper walls 41a to 44a sequentially decrease from the outer side to the inner side in the vehicle width direction (tu1>tu2>tu3>tu4). Similarly, the thicknesses tl1 to tl4 of the first to fourth lower walls 41b to 44b sequentially decrease from the outer side to the inner side in the vehicle width direction (tl1>tl2>tl3>tl4). Therefore, as the deformation region expands in the vehicle fore-and-aft direction as the side collision progresses, the deformation strength of the reinforcing member sequentially decreases from the outer side to the inner side in the vehicle width direction. This allows the impact load, which tends to increase as the deformation progresses, to be evened out.

[0066] Furthermore, since the innermost closed cross-sectional portion 41 is excluded from the thickness relationship, the area outside the innermost closed cross-sectional portion 41 in the vehicle width direction is less likely to deform when crushed, thereby ensuring high vehicle interior protection performance.

[0067] Furthermore, since the reinforcing member 40 is disposed adjacent to the side sill 20, the side sill 20 can be reinforced easily.

[0068] Furthermore, by using an extruded material made of an aluminum alloy as the reinforcing member 40, the thickness of a portion of the reinforcing member 40 can be easily changed.

[0069] (Second embodiment) 8 and 9 is substantially the same as the first embodiment except for the configuration related to the arrangement and shape of the reinforcing member 40 and the shape of the side sill 20. Therefore, a description of the same parts as the first embodiment may be omitted.

[0070] In this embodiment, the reinforcing member 40 is disposed on the inner side of the side sill 20 in the vehicle width direction, and is joined to the inner member 22 of the side sill 20 with bolts (not shown). The inner member 22 has a stepped portion 22a having a shape complementary to the reinforcing member 40. The reinforcing member 40 is disposed in the stepped portion 22a.

[0071] In this embodiment, the multiple closed cross-sectional portions 40a in the reinforcing member 40 include four closed cross-sectional portions 41 to 44, with the fourth closed cross-sectional portion 44 being disposed furthest inward in the vehicle width direction. That is, the multiple closed cross-sectional portions 40a include, in order from the outer side in the vehicle width direction, a first closed cross-sectional portion (outermost closed cross-sectional portion) 41, a second closed cross-sectional portion 42, a third closed cross-sectional portion 43, and a fourth closed cross-sectional portion (innermost closed cross-sectional portion) 44. The fourth closed cross-sectional portion 44 has an innermost wall 44d that connects the inner ends in the vehicle width direction of the fourth upper wall 44a and the fourth lower wall 44b and extends in the vehicle up-down direction.

[0072] The dimensional relationships between the first to fourth closed cross-sectional portions 41 to 44 are as follows.

[0073] Preferably, the thickness ts1 of the first side wall 41c is less than the thickness tu1 of the first upper wall 41a. and The thickness ts1 of the first side wall 41c is preferably 1.4 times or less than the thickness tl1 of the first lower wall 41b (ts1≦1.4tu1 or ts1≦1.4tl1). and The thickness tl1 of the first lower wall 41b is 1.2 times or more (ts1≧1.2tu1 and More preferably, the thickness ts1 of the first side wall 41c is less than the thickness tu1 of the first upper wall 41a. and The thickness tl1 of the first lower wall 41b is 1.3 times or more (ts1≧1.3tu1 and ts1 ≥ 1.3tl1).

[0074] The thicknesses ts1 to ts3 of the first to third side walls 41c to 43c of the first to third closed cross-sectional portions 41 to 43, excluding the fourth closed cross-sectional portion (innermost closed cross-sectional portion) 44, decrease sequentially from the outer side to the inner side in the vehicle width direction (ts1>ts2>ts3).

[0075] Furthermore, thicknesses tu1 to tu3 of the first to third upper walls 41a to 43a of the first to third closed cross-sectional portions 41 to 43, excluding the fourth closed cross-sectional portion (innermost closed cross-sectional portion) 44, decrease sequentially from the outer side to the inner side in the vehicle width direction (tu1>tu2>tu3). Similarly, thicknesses tl1 to tl3 of the first to third lower walls 41b to 43b of the first to third closed cross-sectional portions 41 to 43, excluding the fourth closed cross-sectional portion (innermost closed cross-sectional portion) 44, decrease sequentially from the outer side to the inner side in the vehicle width direction (tl1>tl2>tl3).

[0076] In this embodiment, the multiple closed cross-sectional portions 40a include a seventh closed cross-sectional portion 47 that is disposed adjacent to and below the fourth closed cross-sectional portion 44. The seventh closed cross-sectional portion 47 has a rectangular shape that is slightly smaller than the fourth closed cross-sectional portion 44, and is located below the battery unit 10. Below the battery unit 10, multiple cross members 32 that extend in the vehicle width direction are provided. The cross members 32 extend in the vehicle width direction along the lower surfaces of the battery units 10.

[0077] The seventh closed cross-sectional portion 47 includes a seventh upper wall 47a and a seventh lower wall 47b that extend in the vehicle width direction and are disposed facing each other and spaced apart in the vehicle up-down direction. The seventh upper wall 47a is disposed relatively higher, and the seventh lower wall 47b is disposed relatively lower. The seventh upper wall 47a represents the same part as the fourth lower wall 44b, but for convenience, different names and symbols are used.

[0078] The seventh closed cross-sectional portion 47 has a seventh side wall 47c that connects the outer ends of the seventh upper wall 47a and the seventh lower wall 47b in the vehicle width direction and extends in the vehicle up-down direction. The seventh closed cross-sectional portion 47 also has an innermost wall 47d that connects the inner ends of the seventh upper wall 47a and the seventh lower wall 47b in the vehicle width direction and extends in the vehicle up-down direction. The innermost wall 47d is continuous with the innermost wall 44d.

[0079] The seventh lower wall 47b has an extension 47e that extends in the vehicle width direction beyond the innermost wall 47d. Although not shown in detail, the reinforcing member 40 is joined to the cross member 32 at the extension 47e.

[0080] The bolt 60 extends in the vertical direction of the vehicle, passing through the fourth closed cross-section portion 44, the seventh closed cross-section portion 47, the flange portion 13b of the upper case 13, the flange portion 14b of the lower case 14, and the floor panel 30, joining them together.

[0081] According to this embodiment, when a side impact load is applied to the fourth closed cross-sectional portion (innermost closed cross-sectional portion) 44, the side impact load can be transmitted to the cross member 32 through the seventh closed cross-sectional portion 47. Therefore, higher passenger compartment protection performance can be ensured.

[0082] (Third embodiment) 10 and 11 is substantially the same as the first embodiment except for the configuration related to the shape and arrangement of the reinforcing member 40. Therefore, a description of the same parts as the first embodiment may be omitted.

[0083] In this embodiment, the reinforcing member 40 is disposed inside the side sill 20. The reinforcing member 40 is disposed on the outer side of the floor panel 30 and the cross member 31 in the vehicle width direction.

[0084] In this embodiment, the multiple closed cross-sectional portions 40a in the reinforcing member 40 include three closed cross-sectional portions 41 to 43, with the third closed cross-sectional portion 43 being disposed furthest inward in the vehicle width direction. That is, the multiple closed cross-sectional portions 40a include, in order from the outer side in the vehicle width direction, a first closed cross-sectional portion (outermost closed cross-sectional portion) 41, a second closed cross-sectional portion 42, and a third closed cross-sectional portion (innermost closed cross-sectional portion) 43. The third closed cross-sectional portion 43 has an innermost wall 43d that connects the inner ends in the vehicle width direction of the third upper wall 43a and the third lower wall 43b and extends in the vehicle up-down direction.

[0085] The dimensional relationships between the first to third closed cross-sectional portions 41 to 43 are as follows.

[0086] Preferably, the thickness ts1 of the first side wall 41c is less than the thickness tu1 of the first upper wall 41a. andThe thickness ts1 of the first side wall 41c is preferably 1.4 times or less than the thickness tl1 of the first lower wall 41b (ts1≦1.4tu1 or ts1≦1.4tl1). and The thickness tl1 of the first lower wall 41b is 1.2 times or more (ts1≧1.2tu1 and More preferably, the thickness ts1 of the first side wall 41c is less than the thickness tu1 of the first upper wall 41a. and The thickness tl1 of the first lower wall 41b is 1.3 times or more (ts1≧1.3tu1 and ts1 ≥ 1.3tl1).

[0087] The thicknesses ts1 to ts2 of the first and second side walls 41c to 42c of the first and second closed cross-sectional portions 41 to 42, excluding the third closed cross-sectional portion (innermost closed cross-sectional portion) 44, decrease sequentially from the outer side to the inner side in the vehicle width direction (ts1>ts2).

[0088] In this embodiment, the thicknesses tu1 to tu3 of the first to third upper walls 41a to 43a are equal (tu1=tu2=tu3). Similarly, the thicknesses tl1 to tl3 of the first to third lower walls 41b to 43b are equal (tl1=tl2=tl3).

[0089] According to this embodiment, the reinforcing member 40 is disposed in the internal space S2 of the side sill 20, so that the internal space S2 can be effectively utilized and the vehicle side sill reinforcing structure can be made compact.

[0090] As a modification of this embodiment, the reinforcing member 40 may be integral with the side sill 20. For example, the side sill 20 and the reinforcing member 40 may be integrally formed as an extruded member made of an aluminum alloy.

[0091] Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be implemented with various modifications within the scope of the present invention.

[0092] For example, the number of closed cross-sectional portions included in the reinforcing member 40 is not particularly limited, and may be six or more.

[0093] The shape of each closed cross-sectional portion of the reinforcing member 40 is not limited to a rectangle as in the above embodiments, but may be any polygon (such as a trapezoid) having opposing upper and lower walls and side walls connecting them.

[0094] In each of the above embodiments, an electric vehicle is exemplified as the vehicle 1, but the vehicle 1 may also be a gasoline-powered vehicle. From the viewpoint of protecting the passenger compartment, the vehicle side sill reinforcement structure of the above embodiments can be suitably applied to both electric vehicles and gasoline-powered vehicles. [Explanation of symbols]

[0095] 1 vehicle 2. Paul 3. Wall 10 Battery Unit 11 Battery 12 Battery case 13 Upper case 13a Storage section 13b Flange 14 Lower case 14a Storage section 14b Flange part 20 Side sill 21 Outer member 22 Inner member 22a Step 30 Floor Panel 31,32 Cross member 32a end 40 Reinforcement member 41 First closed section (outermost closed section) 41a 1st upper wall 41b 1st lower wall 41c 1st side wall 42 Second closed section 42a Second upper wall 42b Second Lower Wall 42c 2nd side wall 43 Third closed section (innermost closed section) 43a Third Upper Wall 43b 3rd lower wall 43c 3rd side wall 43d innermost wall 44 The 4th closed section (the innermost closed section) 44a 4th upper wall 44b 4th lower wall 44c 4th side wall 44d innermost wall 45 The 5th closed section (the innermost closed section) 45a 5th upper wall 45b 5th lower wall 45c 5th side wall 45d innermost wall 46 6th closed face 46a Upper wall 6 46b 6th lower wall 46c 6th side wall 46d innermost wall 47 7th closed section 47a Upper wall 7 47b 7th lower wall 47c 7th side wall 47d innermost wall 47e extension 60 ボルト 61 カラー 70 ボルト 71 カラー

Claims

1. a side sill extending in the front-rear direction of the vehicle at a side portion of the vehicle; a reinforcing member that reinforces the side sill; Equipped with the reinforcing member has a plurality of closed cross-sectional portions that are continuous in a vehicle width direction in a cross section perpendicular to the vehicle front-rear direction, the plurality of closed cross-sectional portions include an outermost closed cross-sectional portion disposed outermost in the vehicle width direction, the outermost closed cross-sectional portion includes an outermost upper wall and an outermost lower wall that are disposed opposite to each other and spaced apart in the vehicle up-down direction, and an outermost wall that connects outer ends of the outermost upper wall and the outermost lower wall in the vehicle width direction, The thickness of the outermost wall is greater than the thicknesses of the outermost upper wall and the outermost lower wall.

2. 2. The vehicle side sill reinforcement structure according to claim 1, wherein the thickness of the outermost wall is 1.4 times or less the thickness of the outermost upper wall and the outermost lower wall.

3. 3. The vehicle side sill reinforcement structure according to claim 1, wherein the thickness of the outermost wall is 1.2 times or more the thickness of the outermost upper wall and the outermost lower wall.

4. 4. The vehicle side sill reinforcement structure according to claim 3, wherein the thickness of the outermost wall is 1.3 times or more the thickness of the outermost upper wall and the outermost lower wall.

5. the plurality of closed cross-sectional portions include an innermost closed cross-sectional portion disposed innermost in the vehicle width direction, each of the plurality of closed cross-sectional portions includes an upper wall and a lower wall that are disposed opposite to each other and spaced apart in the vehicle up-down direction, and a side wall that connects outer ends of the upper wall and the lower wall in the vehicle width direction; 5. The vehicle side sill reinforcement structure according to claim 1, wherein thicknesses of the side walls of the plurality of closed cross-section portions excluding the innermost closed cross-section portion decrease in order from the outer side to the inner side in the vehicle width direction.

6. a thickness of the upper wall of each of the plurality of closed cross-sectional portions excluding the innermost closed cross-sectional portion decreases sequentially from the outer side to the inner side in the vehicle width direction, 6. The vehicle side sill reinforcement structure according to claim 5, wherein thicknesses of the lower walls of the plurality of closed cross-sectional portions excluding the innermost closed cross-sectional portion decrease in order from the outer side to the inner side in the vehicle width direction.

7. The vehicle side sill reinforcement structure according to claim 1 , wherein the reinforcing member is disposed inside the side sill.

8. The vehicle side sill reinforcing structure according to claim 1 , wherein the reinforcing member is disposed adjacent to the side sill.

9. 9. The vehicle side sill reinforcing structure according to claim 1, wherein the reinforcing member is an extruded member made of an aluminum alloy.

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