Vehicle side sill

Abstract

The present invention provides a side sill for a vehicle, comprising: a first side sill frame; a second side sill frame coupled to the first side sill frame to form a hollow portion together with the first side sill frame; a first reinforcing frame disposed in the hollow portion and having one side joined to the first side sill frame to form a first closed cross section; a partition member joined to the first side sill frame and the second side sill frame to divide the hollow portion and to which the other side of the first reinforcing frame is joined; and a second reinforcing frame disposed in the hollow portion and joined to the partition member to form a second closed cross section, wherein the first reinforcing frame has a bending point that protrudes outward in the first closed cross section.

Description

[Technical Field]

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

[0002] It is to be understood that the material set forth in this section is merely provided as background information for the present invention and may not constitute prior art.

[0003] Side sills applied to environmentally friendly vehicles such as electric vehicles protect not only passengers but also the battery located underneath. Because the battery is relatively large compared to other components of the vehicle, the side space of a vehicle equipped with a battery is relatively narrow compared to a vehicle equipped with an internal combustion engine.

[0004] Therefore, the side sills applied to environmentally friendly vehicles must be able to absorb maximum collision energy within a narrow space and have minimum weight to improve the energy efficiency of the environmentally friendly vehicles.

[0005] For this reason, aluminum extrusion materials have been used for the side sills of environmentally friendly vehicles, but there is still a demand for improved collision energy absorption performance and weight reduction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Utility Model Publication No. 20-1998-0043143 Summary of the Invention [Problem to be solved by the invention]

[0007] One aspect of the present invention is to provide a vehicle side sill that can efficiently absorb collision energy and achieve weight reduction.

[0008] SUMMARY OF THE INVENTION One aspect of the present invention is to provide a side sill for a vehicle that can minimize the amount of fluid entering the interior of the vehicle due to a collision and safely protect occupants and a battery, which is a core component. [Means for solving the problem]

[0009] In one aspect to achieve the above object, the present invention provides a vehicle side sill including: a first side sill frame; a second side sill frame coupled to the first side sill frame to form a hollow portion together with the first side sill frame; a first reinforcing frame disposed in the hollow portion and having one side joined to the first side sill frame to form a first closed cross section; a partition member joined to the first side sill frame and the second side sill frame to divide the hollow portion and to which the other side of the first reinforcing frame is joined; and a second reinforcing frame disposed in the hollow portion and joined to the partition member to form a second closed cross section, wherein the first reinforcing frame has a bending point that protrudes outward from the first closed cross section.

[0010] In another aspect to achieve the above object, the present invention provides a side sill for a vehicle, comprising: a first side sill frame; a second side sill frame coupled to the first side sill frame to form a hollow portion together with the first side sill frame; a first reinforcing frame disposed in the hollow portion and having one side joined to the first side sill frame to form a first closed cross section; and a second reinforcing frame disposed in the hollow portion and having one side joined to the first reinforcing frame to form a second closed cross section, wherein the first reinforcing frame has a bending point that protrudes outward from the first closed cross section.

[0011] At least one of the first side sill frame, the second side sill frame, the first reinforcement frame, and the second reinforcement frame may be made of steel.

[0012] The first reinforcing frame and the second reinforcing frame may include an uneven portion on a cross section in the longitudinal direction of the side sill.

[0013] The uneven portion may have protruding surfaces and recessed surfaces alternately formed in a lengthwise direction of the side sill, and an inclined surface may be formed between the protruding surfaces and the recessed surfaces.

[0014] The protruding surface of the first strengthening frame may overlap the protruding surface of the second strengthening frame, and the recessed surface of the first strengthening frame may overlap the recessed surface of the second strengthening frame.

[0015] The bending point of the first reinforcement frame may be formed at a position spaced apart from a first inner surface of the first side sill frame by a distance of about 30 to 70% of an installation width of the first reinforcement frame.

[0016] The first reinforcement frame can include a first section formed by extending toward a first inner surface of the first side sill frame with the bending point as a boundary, and a second section formed by being bent with the bending point as a boundary and extending toward a second inner surface of the second side sill frame, forming a bending angle with the first section within the first closed cross section.

[0017] The first strengthening frame has a bending angle formed inside the first closed cross section, and the bending angle may be in the range of 165 to 175 degrees.

[0018] The second reinforcing frame may be disposed such that the other side thereof is in contact with the second inner surface of the second side sill frame.

[0019] above The installation width of the first reinforcing frame and the second reinforcing frame does not have to decrease from the second inner surface of the second side sill frame toward the first inner surface of the first side sill frame.

[0020] The first and second strengthening frames may be formed by bending a single steel plate into multiple stages. [Effects of the Invention]

[0021] According to one embodiment of the present invention, the vehicle side sill has the effect of efficiently absorbing collision energy and achieving a lighter weight.

[0022] According to one embodiment of the present invention, a vehicle side sill has an effect of minimizing the amount of fluid entering the interior of a vehicle due to a collision, and safely protecting passengers and a battery, which is a core component. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a perspective view of a vehicle side sill of a first comparative example to be compared with the vehicle side sill of the present invention. FIG. [Figure 2] FIG. 2 is a cross-sectional view of FIG. 1. [Figure 3] FIG. 10 is a perspective view of a vehicle side sill of a second comparative example to be compared with the vehicle side sill of the present invention. [Figure 4] FIG. 4 is a cross-sectional view of FIG. [Figure 5] 1 is a perspective view of a vehicle side sill according to a first embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view of FIG. 5. [Figure 7] 6 is a diagram showing the positions of bending points of the vehicle side sill according to the first embodiment of FIG. 5. FIG. [Figure 8] FIG. 10 is a perspective view of a vehicle side sill according to a second embodiment of the present invention. [Figure 9] FIG. 9 is a cross-sectional view of FIG. 8. [Figure 10] 9 is a diagram showing the positions of bending points of the vehicle side sill according to the second embodiment of FIG. 8. FIG. [Figure 11a] 10 shows the results of deformation analysis of a vehicle side sill of a first comparative example. [Figure 11b] 10 shows the results of deformation analysis of a vehicle side sill of a first comparative example. [Figure 11c]10 shows the results of deformation analysis of a vehicle side sill of a first comparative example. [Figure 12a] 4 shows the deformation analysis results of the vehicle side sill of the first embodiment. [Figure 12b] 4 shows the deformation analysis results of the vehicle side sill of the first embodiment. [Figure 12c] 4 shows the deformation analysis results of the vehicle side sill of the first embodiment. [Figure 13a] 10 shows the results of deformation analysis of a vehicle side sill of a second comparative example. [Figure 13b] 10 shows the results of deformation analysis of a vehicle side sill of a second comparative example. [Figure 13c] 10 shows the results of deformation analysis of a vehicle side sill of a second comparative example. [Figure 14a] 10 shows the results of a deformation analysis of a vehicle side sill according to a second embodiment. [Figure 14b] 10 shows the results of a deformation analysis of a vehicle side sill according to a second embodiment. [Figure 14c] 10 shows the results of a deformation analysis of a vehicle side sill according to a second embodiment. [Figure 15] 6 is a load-displacement diagram of the vehicle side sill of the first comparative example in FIG. 1 and the first embodiment in FIG. 5. [Figure 16] 9 is a load-displacement diagram of the vehicle side sill of the third comparative example of FIG. 3 and the second embodiment of FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various different forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, the embodiments of the present invention are provided to more completely explain the present invention to those having average knowledge in the art. The shapes and sizes of elements in the drawings may be exaggerated for clarity.

[0025] Hereinafter, the X axis shown in the accompanying drawings is the width direction of the vehicle side sill, the Y axis is the length direction of the vehicle side sill, and the Z axis is the height direction of the vehicle side sill.

[0026] FIG. 1 is a perspective view of a vehicle side sill of a first comparative example to be compared with the vehicle side sill of the present invention, and FIG. 2 is a cross-sectional view of FIG.

[0027] The first comparative example differs from the first embodiment described later in that the first reinforcement frame 300 does not have bending points 370 that protrude outward (in the Z-axis direction) at the first closed cross section M1.

[0028] In the case of the first comparative example, there is a problem that the deformation of the first reinforcement frame 300 and the second reinforcement frame 400 is not normal in the X-axis direction, but rather tilts in the Z-axis direction, which can be a major concern in terms of providing stable collision energy absorption performance under various collision environments.

[0029] FIG. 3 is a perspective view of a vehicle side sill of a second comparative example to be compared with the vehicle side sill of the present invention, and FIG. 4 is a cross-sectional view of FIG.

[0030] The second comparative example differs from the second embodiment described later in that the first reinforcement frame 300 does not have bending points 370 that protrude outward (in the Z-axis direction) at the first closed cross section M1.

[0031] In the case of the second comparative example, the first reinforcement frame 300 and the second reinforcement frame 400 are not crushed normally in the X-axis direction, and deformation occurs that tilts in the Z-axis direction. This can be a major concern in terms of providing stable collision energy absorption performance under various collision environments.

[0032] Hereinafter, the components included in the vehicle side sills according to the first and second embodiments will be described in detail with reference to FIGS.

[0033] FIG. 5 is a perspective view of a vehicle side sill according to a first embodiment of the present invention, FIG. 6 is a cross-sectional view of FIG. 5, and FIG. 7 is a diagram showing the position U of the bending point 370 of the vehicle side sill according to the first embodiment of FIG. 5.

[0034] FIG. 8 is a perspective view of a vehicle side sill according to a second embodiment of the present invention, FIG. 9 is a cross-sectional view of FIG. 8, and FIG. 10 is a diagram showing the position U of the bending point 370 of the vehicle side sill according to the second embodiment of FIG. 8.

[0035] The vehicle side sill according to the first embodiment may include a first side sill frame 100 , a second side sill frame 200 , a first reinforcing frame 300 , a partition member 500 and a second reinforcing frame 400 .

[0036] The first side sill frame 100 can be disposed on the inner side of the width direction of the side sill in the X-axis direction.

[0037] The second side sill frame 200 may be coupled to the first side sill frame 100 to form a hollow portion S together with the first side sill frame 100 .

[0038] The second side sill frame 200 may be disposed on the outer side of the side sill in the width direction in the X-axis direction. The second side sill frame 200 may be joined to the first side sill frame 100 by welding or the like.

[0039] The first reinforcement frame 300 is disposed in the hollow portion S, and one side thereof is joined to the first side sill frame 100 to form a first closed cross section M1.

[0040] The first reinforcing frame 300 may have bending points 370 that protrude outward (in the Z-axis direction) at the first closed cross section M1.

[0041] The first reinforcing frame 300 is joined to the first side sill frame 100 to form the first closed cross section M1, thereby improving the mechanical rigidity of the vehicle side sill.

[0042] The first reinforcing frame 300 can include a first upper flange 310, a pair of first web members 330, and a pair of first lower flanges 350 on the XZ axis cross section of the side sill.

[0043] A first web member 330 may be connected to each of both ends of the first upper flange 310 in the height direction.

[0044] The first upper flange 310 can be joined to the diaphragm member 500 .

[0045] The first upper flange 310 may be flat, which can improve the adhesive strength of the first upper flange 310 when applying an adhesive or the like to the first upper flange 310, thereby improving the convenience of the bonding and assembly operations.

[0046] The first web member 330 may be formed to extend from the first upper flange 310 and extend toward the first inner surface 110 of the first side sill frame 100 .

[0047] The first reinforcing frame 300 can be bent so that the first web member 330 and the first lower flange 350 are arranged in a crosswise relationship.

[0048] The first web member 330 may be formed at an angle and may extend immediately before the dividing sheet member 500 without contacting the first side sill frame 100. This makes it easier for the first reinforcing frame 300 to undergo compressive deformation in the load direction when a load is applied in the X-axis direction.

[0049] The first lower flange 350 may be joined to the first inner surface 110 of the first side sill frame 100 .

[0050] The partition member 500 is joined to the first side sill frame 100 and the second side sill frame 200 to divide the hollow portion S, and the other side of the first reinforcement frame 300 may be joined thereto.

[0051] The first reinforcement frame 300 may be joined to one side of the barrier member 500, and the second reinforcement frame 400 may be joined to the other side.

[0052] The partition member 500 is located between the first side sill frame 100 and the second side sill frame 200, and one side thereof may be joined to the first side sill frame 100 and the second side sill frame 200, and the other side thereof may be joined to the first side sill frame 100 and the second side sill frame 200.

[0053] When a load is applied in the X-axis direction, the partition member 500 enables the first side sill frame 100 and the second side sill frame 200 to stably undergo compressive deformation in the load direction. Therefore, the partition member 500 can play a role in improving the collision energy absorption performance.

[0054] The second reinforcement frame 400 is disposed in the hollow portion S and can be joined to the diaphragm member 500 to form a second closed cross section M2.

[0055] The second reinforcement frame 400 is joined at one side to the dividing sheet member 500 to form a second closed cross section M2, thereby improving the mechanical rigidity of the vehicle side sill.

[0056] The second reinforcing frame 400 can include a second upper flange 410, a pair of second web members 430, and a pair of second lower flanges 450 on the XZ axis cross section of the side sill.

[0057] The second upper flange 410 may be flat. This can improve the adhesive strength of the second upper flange 410 when an adhesive or the like is applied to the second upper flange 410 for bonding to the second side sill frame 200, thereby improving the convenience of bonding and assembly operations.

[0058] The second upper flange 410 may have second web members 430 connected to both ends in the height direction.

[0059] The second web member 430 may be formed to extend from the second upper flange 410 and extend toward the first inner surface 110 of the first side sill frame 100 .

[0060] The second lower flange 450 of the second reinforcement frame 400 can be joined to the diaphragm member 500 .

[0061] The second lower flange 450 can be fixed in contact with the dividing membrane member 500, and the second web member 430 can extend to just in front of the second side sill frame 200 without contacting the second side sill frame 200. This makes it easier for the second reinforcing frame 400 to undergo compressive deformation in the load direction when a load is applied in the X-axis direction.

[0062] A first mating surface may be present on the first upper flange 310, and a second mating surface may be present on the second upper flange 410.

[0063] The first and second bonding surfaces may be flat, which can improve bonding performance.

[0064] The first upper flange 310 may be continuously present over a certain section in a direction parallel to the Y axis, and may be in contact with the barrier member 500 over a certain section.

[0065] The second upper flange 410 may be continuously present over a certain section in a direction parallel to the Y axis, and may be in contact with the second side sill frame 200 over a certain section.

[0066] Therefore, the first and second bonding surfaces can be continuously present over a certain distance in the Y-axis direction, and the entire first bonding surface is bonded to the barrier membrane member 500, and the entire second bonding surface is bonded to the second side sill frame 200, thereby improving bonding performance.

[0067] As an example, the first side sill frame 100 and the first reinforcing frame 300 may be joined by spot welding, the first reinforcing frame 300 and the partition member 500 may be bonded with an adhesive, and the second reinforcing frame 400 and the second side sill frame 200 may be bonded with an adhesive.

[0068] The diaphragm member 500 and the second reinforcing frame 400 may be joined by spot welding, and the first side sill frame 100 and the second side sill frame 200 may be joined by spot welding.

[0069] Of course, various joining methods such as welding or adhesive joining can be applied to join components such as the first side sill frame 100, the second side sill frame 200, the first reinforcing frame 300, the partition member 500, and the second side sill frame 200.

[0070] At least one of the first side sill frame 100, the second side sill frame 200, the first reinforcing frame 300, and the second reinforcing frame 400 can be formed by form forming or crush forming a steel plate, which can contribute to reducing manufacturing costs by reducing mold costs, etc.

[0071] The first side sill frame 100, the second side sill frame 200, the first reinforcing frame 300 and the second reinforcing frame 400 may be made of ultra-high strength steel having a tensile strength of 980 MPa or more.

[0072] As an example, the first side sill frame 100 and the second side sill frame 200 may be made of a material including 1470 MART steel, and the first reinforcement frame 300 and the second reinforcement frame 400 may be made of a material including 1180 TRIP steel.

[0073] 8 to 10, the vehicle side sill according to the second embodiment may include a first side sill frame 100, a second side sill frame 200, a first reinforcing frame 300, and a second reinforcing frame 400.

[0074] The vehicle side sill according to the second embodiment differs in that the dividing sheet member 500 between the first reinforcement frame 300 and the second reinforcement frame 400 is removed, but the remaining components may be the same as those of the vehicle side sill according to the first embodiment. Therefore, the following description will mainly focus on the components of the second embodiment that are different from those of the first embodiment.

[0075] The first reinforcing frame 300 can include a first upper flange 310, a pair of first web members 330, and a pair of first lower flanges 350 on the XZ axis cross section of the side sill.

[0076] A first web member 330 may be connected to each of both heightwise ends of the first upper flange 310. The second lower flange 450 may be joined to the first web member 330, so that the first upper flange 310 may be disposed at the boundary between the first closed cross section M1 and the second closed cross section M2.

[0077] The second reinforcement frame 400 is disposed in the hollow portion S, and one side of the second reinforcement frame 400 is joined to the first reinforcement frame 300 to form a second closed cross section M2.

[0078] The second reinforcing frame 400 is joined to the first reinforcing frame 300 at one side to form a second closed cross section M2, thereby improving the mechanical rigidity of the vehicle side sill.

[0079] The second reinforcing frame 400 can include a second upper flange 410, a pair of second web members 430, and a pair of second lower flanges 450 on the XZ axis cross section of the side sill.

[0080] The second lower flange 450 of the second reinforcing frame 400 can be joined to the first web member 330 of the first reinforcing frame 300 .

[0081] The second lower flanges 450 may have a step formed between the second web members 430, and the spacing between the pair of second lower flanges 450 in the Z-axis direction may be wider than the spacing between the pair of second web members 430 in the Z-axis direction.

[0082] As an example, the first side sill frame 100 and the first reinforcement frame 300 can be joined by spot welding, the first reinforcement frame 300 and the second reinforcement frame 400 can be joined by laser welding or spot welding, and the second side sill frame 200 and the second reinforcement frame 400 can be joined by adhesive.

[0083] The first side sill frame 100 and the second side sill frame 200 can be joined by spot welding.

[0084] Of course, various joining methods such as welding or adhesive bonding can be applied to join components such as the first reinforcement frame 300, the second reinforcement frame 400, the first side sill frame 100, and the second side sill frame 200.

[0085] At least one of the first side sill frame 100, the second side sill frame 200, the first reinforcement frame 300, and the second reinforcement frame 400 may be made of steel.

[0086] As an example, the first side sill frame 100, the second side sill frame 200, the first reinforcing frame 300, and the second reinforcing frame 400 may be made of steel, thereby improving the mechanical rigidity of the vehicle side sill.

[0087] The first reinforcing frame 300 and the second reinforcing frame 400 may include an uneven portion P on a cross section in the longitudinal direction of the side sill.

[0088] The first and second reinforcing frames 300 and 400 may have a concave-convex portion P repeated in the length direction.

[0089] By including the uneven portion P, the first reinforcing frame 300 and the second reinforcing frame 400 can improve rigidity without increasing the thickness of the steel material or the like that constitutes the first reinforcing frame 300 and the second reinforcing frame 400.

[0090] Concave The convex portion P has protruding surfaces P1 and recessed surfaces P2 formed alternately in the length direction of the side sill, and an inclined surface P3 may be formed between the protruding surface P1 and the recessed surface P2.

[0091] The protruding surface P1 of the first reinforcement frame 300 can overlap the protruding surface P1 of the second reinforcement frame 400, and the recessed surface P2 of the first reinforcement frame 300 can overlap the recessed surface P2 of the second reinforcement frame 400.

[0092] The protruding surfaces P1 of the first reinforcement frame 300 and the second reinforcement frame 400 overlap each other, and the recessed surfaces P2 of the first reinforcement frame 300 and the second reinforcement frame 400 overlap each other, which has the effect of improving the bonding strength between the first reinforcement frame 300 and the second reinforcement frame 400.

[0093] Since the protruding surfaces P1 of the first reinforcing frame 300 and the second reinforcing frame 400 overlap each other and the recessed surfaces P2 of the first reinforcing frame 300 and the second reinforcing frame 400 overlap each other, the joining position of the first reinforcing frame 300 and the second reinforcing frame 400 can be naturally guided, which has the effect of improving the workability of the worker.

[0094] The bending point 370 of the first reinforcing frame 300 may be formed at a distance of 30 to 70% of the installation width T of the first reinforcing frame 300 from the first inner surface 110 of the first side sill frame 100 .

[0095] If the position of the bending point 370 is less than 30% or more than 70% of the installation width T of the first reinforcement frame 300 from the first inner surface 110 of the first side sill frame 100, bending guidance will not be performed well at the bending point 370 of the first reinforcement frame 300, and normal crushing may not occur.

[0096] If normal crushing does not occur in the first reinforcing frame 300, tilting deformation may occur, as in the comparative example described above, resulting in a problem of insufficient load-bearing performance. Furthermore, this may be a major concern in terms of the vehicle side sill's ability to stably absorb collision energy under various collision environments.

[0097] The first reinforcing frame 300 may include a first section 331 and a second section 333 .

[0098] The first section 331 may be formed to extend in the direction of the first inner surface 110 of the first side sill frame 100 with the bending point 370 as a boundary.

[0099] The second section 333 is bent at the bending point 370 as a boundary and extends toward the second inner surface 210 of the second side sill frame 200, and can form a bending angle 390 with the first section 331 within the first closed cross section M1.

[0100] There may be a bend point 370 at the boundary between the first section 331 and the second section 333 .

[0101] The first reinforcement frame 300 may be bent into a first section 331 and a second section 333 with a bending point 370 as a boundary.

[0102] A bend angle 390 is formed within the first closed cross section M1 and may be comprised of less than 180 degrees.

[0103] The first strengthening frame 300 has a bending angle 390 formed inside the first closed cross section M1, and the bending angle 390 may be in the range of 165 to 175 degrees. The angle θ formed between the extension line of the first section 331 and the extension line of the second section 333 may be in the range of 5 to 15 degrees.

[0104] The first section 331 and the second section 333 are bent with respect to the bending point 370, so that a bending angle 390 may be formed inside the first closed cross section M1.

[0105] The first strengthening frame 300 has a bending angle 390 in the range of 165 to 175 degrees, so that bending can be stably induced at the bending point 370 while ensuring sufficient rigidity of the first strengthening frame 300.

[0106] If the bending angle 390 of the first reinforcement frame 300 is less than 165 degrees, bending can be induced well at the bending point 370, but if bending is induced too easily at the bending point 370 of the first reinforcement frame 300, there is a possibility that the first reinforcement frame 300 may bend at the bending point 370 before it can achieve its designed load-bearing capacity, thereby reducing its load-bearing capacity.

[0107] The first reinforcing frame 300 may not collapse normally, but may be deformed to tilt as in the comparative example, resulting in insufficient load-bearing capacity. This may also be a major concern in preventing the vehicle side sill from stably absorbing collision energy under various collision conditions.

[0108] If the bending angle 390 exceeds 175 degrees, bending guidance at the bending point 370 may not be performed well, and normal crushing may not occur.

[0109] In this case, the first reinforcement frame 300 does not collapse normally, but instead tilts as in the comparative example, which may result in a problem that the designed load capacity cannot be achieved.

[0110] The second reinforcement frame 400 may be disposed such that the other side thereof is in contact with the second inner surface 210 of the second side sill frame 200 .

[0111] The second reinforcement frame 400 may be disposed so that one side thereof contacts the first reinforcement frame 300 and the other side thereof contacts the second inner surface 210 of the second side sill frame 200 .

[0112] The second reinforcement frame 400 may be joined to the first reinforcement frame 300 at one side and to the second inner surface 210 of the second side sill frame 200 at the other side.

[0113] As a result, when an impact is applied to the second side sill frame 200 side, it is primarily cushioned by the second reinforcing frame 400 in contact with the second side sill frame 200, and secondarily cushioned by the first reinforcing frame 300 in contact with the second reinforcing frame 400, thereby having the effect of stably absorbing the impact energy applied to the side sill.

[0114] The installation width of the first reinforcing frame 300 and the second reinforcing frame 400 does not need to decrease as it moves from the second inner surface 210 of the second side sill frame 200 toward the first inner surface 110 of the first side sill frame 100 .

[0115] For example, the installation width of the first reinforcement frame 300 and the second reinforcement frame 400 may increase from the first inner surface 110 of the first side sill frame 100 toward the second inner surface 210 of the second side sill frame 200 .

[0116] As another example, the installation width of the first reinforcement frame 300 and the second reinforcement frame 400 may increase as they move from the first inner surface 110 of the first side sill frame 100 toward the second inner surface 210 of the second side sill frame 200, or they may have at least the same installation width but may not decrease.

[0117] An impact can be applied in the X-axis direction on the second side sill frame 200 side, and if the installation width of the first and second reinforcing frames 300, 400 increases in the direction away from the point where the impact is applied, the first and second reinforcing frames 300, 400 can easily compress and deform in the direction where the impact is applied, resulting in excellent load-bearing performance.

[0118] The first strengthening frame 300 and the second strengthening frame 400 can be formed by bending a single steel plate into multiple stages.

[0119] The first and second reinforcing frames 300, 400 can be formed by bending a single steel plate in multiple stages. By forming the first reinforcing frame 300 by bending a single steel plate in multiple stages, the first and second reinforcing frames 300, 400, which are made of a single steel plate, behave as a single unit, thereby improving the mechanical rigidity of the vehicle side sill.

[0120] Below, the results of deformation analysis of the vehicle side sill of the first comparative example and the vehicle side sill of the first embodiment will be described with reference to FIGS. 11a to 12c.

[0121] 11a to 11c show the results of deformation analysis of the vehicle side sill of the first comparative example.

[0122] FIG. 11a shows the deformation analysis results for the first comparative example in the early stage of the collision, FIG. 11b shows the deformation analysis results for the first comparative example in the middle stage of the collision, and FIG. 11c shows the deformation analysis results for the first comparative example in the later stage of the collision.

[0123] In the first comparative example, it can be seen that the second side sill frame 200 and the second reinforcing frame 400 are compressively deformed in the X-axis direction at the initial stage of the collision.

[0124] In the first comparative example, it is found that the first side sill frame 100, the first reinforcing frame 300, the second side sill frame 200, the second reinforcing frame 400, and the partition member 500 are compressively deformed in the X-axis direction during the middle stage of the collision, and that the amount of compressive deformation in the X-axis direction is greater than the amount of tensile deformation in the Z-axis direction.

[0125] In the first comparative example, in the middle and later stages of the collision, the first reinforcement frame 300 and the second reinforcement frame 400 are not crushed normally in the X-axis direction, and deformation occurs that is inclined in the Z-axis direction, and they are not compressed uniformly in the X-axis direction.

[0126] This poses a problem in that it can be a major factor in terms of achieving stable collision energy absorption performance under various collision environments.

[0127] 12a to 12c show the results of deformation analysis of the vehicle side sill of the first embodiment.

[0128] FIG. 12a shows the deformation analysis results for the first embodiment at the early stage of the collision, FIG. 12b shows the deformation analysis results for the first embodiment at the middle stage of the collision, and FIG. 12c shows the deformation analysis results for the first embodiment at the late stage of the collision.

[0129] In the first embodiment, it can be seen that the second side sill frame 200 and the second reinforcing frame 400 are compressively deformed in the X-axis direction at the initial stage of a collision.

[0130] In the first embodiment, it is found that in the middle of the collision, the first side sill frame 100, the first reinforcing frame 300, the second side sill frame 200, the second reinforcing frame 400, and the partition member 500 are compressively deformed in the X-axis direction, and that the amount of compressive deformation in the X-axis direction is greater than the amount of tensile deformation in the Z-axis direction.

[0131] In the first embodiment, bending is induced at the bending point 370 of the first reinforcing frame 300 during the middle and late stages of the collision, and the first reinforcing frame 300 and the second reinforcing frame 400 are uniformly compressed in the X-axis direction without deformation being biased to one side.

[0132] Below, the results of deformation analysis of the vehicle side sill of the second comparative example and the vehicle side sill of the second embodiment will be described with reference to FIGS. 13a to 14c.

[0133] 13a to 13c show the results of deformation analysis of the vehicle side sill of the second comparative example.

[0134] FIG. 13a shows the deformation analysis results for the second comparative example in the early stage of the collision, FIG. 13b shows the deformation analysis results for the second comparative example in the middle stage of the collision, and FIG. 13c shows the deformation analysis results for the second comparative example in the later stage of the collision.

[0135] In the second comparative example, it can be seen that the second side sill frame 200 and the second reinforcing frame 400 are compressively deformed in the X-axis direction at the initial stage of the collision.

[0136] In the second comparative example, during the middle and later stages of the collision, the first reinforcement frame 300 and the second reinforcement frame 400 are not crushed normally in the X-axis direction, and deformation occurs that tilts in the Z-axis direction, and they are not compressed uniformly in the X-axis direction.

[0137] This poses a problem in that it can be a major factor in terms of achieving stable collision energy absorption performance under various collision environments.

[0138] 14a to 14c show the results of deformation analysis of the vehicle side sill of the second embodiment.

[0139] FIG. 14a shows the deformation analysis results for the second embodiment in the early stage of the collision, FIG. 14b shows the deformation analysis results for the second embodiment in the middle stage of the collision, and FIG. 14c shows the deformation analysis results for the second embodiment in the later stage of the collision.

[0140] In the second embodiment, it can be seen that the second side sill frame 200 and the second reinforcing frame 400 are compressively deformed in the X-axis direction at the initial stage of a collision.

[0141] In the second embodiment, it is found that the first side sill frame 100, the first reinforcing frame 300, the second side sill frame 200, the second reinforcing frame 400, and the partition member 500 are compressively deformed in the X-axis direction during the middle stage of the collision, and that the amount of compressive deformation in the X-axis direction is greater than the amount of tensile deformation in the Z-axis direction.

[0142] In the second embodiment, bending is induced at the bending point 370 of the first reinforcement frame 300 during the middle and late stages of the collision, and the first reinforcement frame 300 and the second reinforcement frame 400 are uniformly compressed in the X-axis direction without deformation being biased to one side.

[0143] FIG. 15 is a load-displacement diagram of the vehicle side sill of the first comparative example in FIG. 1 and the first embodiment in FIG.

[0144] The load-displacement value of the vehicle side sill of the first comparative example in FIG. 1 is indicated by a first value L1, and the load-displacement value of the vehicle side sill of the first embodiment in FIG. 5 is indicated by a second value L2.

[0145] First value L 1 and the second value L 2 5, it can be seen that the displacement of the vehicle side sill of the first embodiment in FIG. 5 is relatively smaller than that of the vehicle side sill of the first comparative example in FIG. 1 under the same load.

[0146] In the case of the first value L1, the impact absorption capacity drops sharply at a displacement of 60 mm or more, which corresponds to the later stage of the collision, whereas in the case of the second value L2, the impact is absorbed stably even in the later stage of the collision.

[0147] Specifically, the internal energy of the vehicle side sill of the first comparative example is 43.8 KJ, the weight of the vehicle side sill of the first comparative example is 19.9 kg, the internal energy of the vehicle side sill of the first embodiment is 50.2 KJ, and the weight of the vehicle side sill of the first embodiment is 20.5 kg.

[0148] In other words, the vehicle side sill of the first comparative example has an internal energy rate per kg of 2.19 (KJ / kg), while the vehicle side sill of the first example has an internal energy rate per kg of 2.45 (KJ / kg). This shows that the first example has a higher internal energy rate per kg than the first comparative example, and is therefore superior in energy absorption performance per unit weight.

[0149] FIG. 16 is a load-displacement diagram of the vehicle side sill of the third comparative example in FIG. 3 and the second embodiment in FIG.

[0150] The load-displacement value of the vehicle side sill of the second comparative example in FIG. 3 is indicated by a first value L1, and the load-displacement value of the vehicle side sill of the second embodiment in FIG. 8 is indicated by a first value L2.

[0151] First value L 1 and the second value L 2 7, it can be seen that the displacement of the vehicle side sill of the third embodiment in FIG. 7 is almost similar to that of the vehicle side sill of the second comparative example in FIG. 3 under the same load.

[0152] Specifically, the internal energy of the vehicle side sill of the second comparative example is 51.2 KJ, the weight of the vehicle side sill of the second comparative example is 18.3 kg, the internal energy of the vehicle side sill of the second embodiment is 51.7 KJ, and the weight of the vehicle side sill of the second embodiment is 18.9 kg.

[0153] In other words, the vehicle side sill of the second comparative example has an internal energy rate per kg of 2.80 (KJ / kg), while the vehicle side sill of the second example has an internal energy rate per kg of 2.74 (KJ / kg), so there is not much difference in the energy absorption performance per unit weight between the second example and the second comparative example.

[0154] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it is obvious to those skilled in the art that various modifications and variations are possible within the scope that does not deviate from the technical idea of ​​the present invention described in the claims. [Explanation of symbols]

[0155] 100: First side sill frame 110: First inner surface 200: Second side sill frame 210: Second inner surface 300: First reinforced frame 310: First upper flange 330: First web member 331: First Section 333:Second Section 350: First lower flange 370: Bending point 390: Bending angle 400: Second reinforced frame 410: Second upper flange 430: Second web member 450: Second lower flange 500: Diaphragm material M1: 1st closed section M2: 2nd closed section P: Uneven part P1:Protruding surface P2: Concave surface P3: Inclined surface S: Hollow part T: Installation width of the first reinforcement frame U: Position of bending point

Claims

1. a first side sill frame; a second side sill frame coupled to the first side sill frame to form a hollow portion together with the first side sill frame; a first reinforcing frame disposed in the hollow portion, one side of which is joined to the first side sill frame to form a first closed cross section; a partition member joined to the first side sill frame and the second side sill frame to divide the hollow portion and to which the other side of the first reinforcement frame is joined; a second reinforcing frame disposed in the hollow portion and joined to the diaphragm member to form a second closed cross section, The first reinforcing frame is a first upper flange; a pair of first web members respectively connected to both side ends of the first upper flange in a height direction and extending in a direction toward a first inner surface of the first side sill frame; a pair of first lower flanges joined to a first inner surface of the first side sill frame, The second reinforcing frame is a second upper flange; a pair of second web members respectively connected to both side ends of the second upper flange in a height direction and extending toward a first inner surface of the first side sill frame; a pair of second lower flanges joined to the diaphragm member; The first web member of the first stiffening frame is A vehicle side sill having a bending point that protrudes outward in the first closed cross section.

2. a first side sill frame; a second side sill frame coupled to the first side sill frame to form a hollow portion together with the first side sill frame; a first reinforcing frame disposed in the hollow portion, one side of which is joined to the first side sill frame to form a first closed cross section; a second reinforcement frame disposed in the hollow portion, one side of which is joined to the first reinforcement frame to form a second closed cross section; The first reinforcing frame is a first upper flange; a pair of first web members respectively connected to both side ends of the first upper flange in a height direction and extending in a direction toward a first inner surface of the first side sill frame; a pair of first lower flanges joined to a first inner surface of the first side sill frame, The second reinforcing frame is a second upper flange; a pair of second web members respectively connected to both side ends of the second upper flange in a height direction and extending toward a first inner surface of the first side sill frame; a pair of second lower flanges joined to the first web member; The first web member of the first stiffening frame is A vehicle side sill having a bending point that protrudes outward in the first closed cross section.

3. The vehicle side sill according to claim 1 or 2, wherein at least one of the first side sill frame, the second side sill frame, the first reinforcing frame, and the second reinforcing frame is made of steel.

4. The first reinforcement frame and the second reinforcement frame are The vehicle side sill according to claim 1 or 2, wherein the vehicle side sill includes an uneven portion on a cross section in a longitudinal direction thereof.

5. The uneven portion is 5. The vehicle side sill according to claim 4, wherein protruding surfaces and recessed surfaces are alternately formed in the longitudinal direction of the vehicle side sill, and an inclined surface is formed between the protruding surfaces and the recessed surfaces.

6. The vehicle side sill according to claim 5 , wherein the protruding surface of the first reinforcement frame overlaps the protruding surface of the second reinforcement frame, and the recessed surface of the first reinforcement frame overlaps the recessed surface of the second reinforcement frame.

7. The first reinforcing frame is 3. The vehicle side sill according to claim 1, wherein the bending point is formed at a position spaced apart from the first inner surface of the first side sill frame by a distance of 30 to 70% of the installation width of the first reinforcement frame.

8. The first reinforcing frame is a first section formed by extending in a direction toward a first inner surface of the first side sill frame with the bending point as a boundary; a second section that is bent with the bending point as a boundary and extends toward a second inner surface of the second side sill frame, and that forms a bending angle with the first section within the first closed cross section.

9. The first reinforcing frame is 9. The vehicle side sill according to claim 8, wherein the bending angle is formed inside the first closed cross section, and the bending angle is in the range of 165 to 175 degrees.

10. The vehicle side sill according to claim 1 or 2, wherein the second reinforcing frame is disposed such that the other side thereof is in contact with a second inner surface of the second side sill frame.

11. The installation width of the first reinforcement frame and the installation width of the second reinforcement frame are: The vehicle side sill according to claim 1 or 2, wherein an installation width does not decrease from the second inner surface of the second side sill frame toward the first inner surface of the first side sill frame.

12. The first reinforcement frame and the second reinforcement frame are 3. The vehicle side sill according to claim 1, wherein the side sill is formed by bending a single steel plate in multiple stages.

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