Vehicle side sill

Abstract

A side sill for a vehicle according to one embodiment of the present invention includes: a side sill frame formed to have a hollow portion; a first reinforcing frame disposed in the hollow portion and joined to the side sill frame; and a second reinforcing frame disposed in the hollow portion and joined to the first reinforcing frame and the side sill frame; and the first reinforcing frame and the second reinforcing frame can be disposed in the hollow portion so as to form a closed cross section in the hollow portion in a cross section in the thickness direction of the side sill frame.

Description

[Technical field]

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

[0002] Vehicle side sills serve to protect passengers by absorbing collision energy during a side collision.

[0003] Side sills applied to environmentally friendly vehicles such as electric vehicles protect not only passengers but also the battery located on the floor. Since the battery is relatively large in volume 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 sill applied to the environmentally friendly vehicle 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 vehicle.

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

[0006] [Patent Document 1] Korean Utility Model Publication No. 20-1998-0043143 (1998.09.25) Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to improve the collision energy absorption efficiency of a side sill and to achieve weight reduction.

[0008] An object of the present invention is to increase the rigidity of a side sill and reduce manufacturing costs. [Means for solving the problem]

[0009] A side sill for a vehicle according to one embodiment of the present invention includes a side sill frame formed to have a hollow portion, a first reinforcing frame disposed in the hollow portion and joined to the side sill frame, and a second reinforcing frame disposed in the hollow portion and joined to the first reinforcing frame and the side sill frame, and the first reinforcing frame and the second reinforcing frame can be disposed in the hollow portion so as to form a closed cross section in the hollow portion in a cross section in the thickness direction of the side sill frame.

[0010] At least one of the side sill frame, the first reinforcement frame and the second reinforcement frame may be made of steel.

[0011] Further, the first and second reinforcing frames may have cross-sectional shapes in a length direction of the side sill frame that include uneven portions.

[0012] Also, the first and second reinforcing frames can overlap at the hollow portion.

[0013] In addition, the uneven portion may have a protrusion and a recess formed continuously in a length direction of the side sill frame.

[0014] Furthermore, the protrusion of the first strengthening frame can overlap the protrusion of the second strengthening frame, and the recess of the first strengthening frame can overlap the recess of the second strengthening frame.

[0015] In addition, the side sill frame may include a first side sill frame to which the first reinforcement frame is joined, and a second side sill frame joined to the first side sill frame and having the second reinforcement frame joined to its inner surface.

[0016] In addition, the cross-sectional shape of the first reinforcement frame in the thickness direction may include a plurality of first lower flange portions formed by bending both ends and joined to the inner surface of the first side sill frame, a plurality of first extension portions each connected to the plurality of first lower flange portions and extending in the direction of the second reinforcement frame, and a first upper flange portion connected to the plurality of first extension portions.

[0017] In addition, the cross-sectional shape of the second reinforcement frame in the thickness direction may include a plurality of second extension portions joined to the first extension portion and extending in the direction of the second side sill frame, and a second upper flange portion connected to the second extension portions and joined to the inner surface of the second side sill frame.

[0018] Additionally, the second upper flange portion may be a flat surface.

[0019] In addition, a cross section of the second strengthening frame in a thickness direction may have a step at the second extension portion.

[0020] In addition, the width between the multiple second extension portions in a cross section of the second reinforcement frame in the thickness direction may be widest from an end of the second extension portion on one side to an end of the second extension portion on the other side.

[0021] Also, an end of the second extension portion may be present on the first extension portion.

[0022] In addition, the first lower flange portion may be welded to the first side sill frame, the second extension portion may be welded to the first extension portion, and the second upper flange portion may be adhesively joined to the second side sill frame. Effect of the Invention

[0023] According to the present invention, the collision energy absorption efficiency of the side sill can be improved and the weight of the side sill can be reduced.

[0024] According to the present invention, the rigidity of the side sill can be increased and the manufacturing cost can be reduced. [Brief description of the drawings]

[0025] [Figure 1] 1 is a perspective view of a vehicle side sill according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a front cross-sectional view of FIG. [Diagram 3] 2 is a view taken along line A-A' in FIG. 1. [Figure 4] 2 is a view taken along line BB' in FIG. 1. [Diagram 5] 1 is a perspective view of a vehicle side sill according to an embodiment of the present invention; [Figure 6] 6 is a view taken along line CC' in FIG. 5. [Figure 7] FIG. 2 is a cross-sectional view of a first reinforcing frame according to one embodiment of the present invention. [Figure 8] FIG. 4 is a cross-sectional view of a second reinforcing frame according to one embodiment of the present invention. [Figure 9] 4 is a deformation analysis result of a vehicle side sill according to an embodiment of the present invention. [Figure 10] 4 is a deformation analysis result of a vehicle side sill according to an embodiment of the present invention. [Figure 11] FIG. 1 is a cross-sectional view of a conventional vehicle side sill. [Figure 12] 12 is a load-displacement diagram of the vehicle side sill of FIG. 1 and the vehicle side sill of FIG. 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] In order to facilitate understanding of the description of the embodiments of the present invention, elements with the same reference numerals in the accompanying drawings are the same elements, and among components that perform the same function in each embodiment, related components are indicated by the same or extended numerals.

[0027] In order to clarify the gist of the present invention, a description of elements and techniques well known in the prior art will be omitted, and the present invention will be described in detail below with reference to the accompanying drawings.

[0028] However, the concept of the present invention is not limited to the embodiments shown, and other forms in which specific components are added, modified, or deleted may be proposed by those skilled in the art, which also fall within the scope of the same concept of the present invention.

[0029] Hereinafter, the X-axis shown in the accompanying drawings is the width direction of the side sill, the Y-axis is the length direction of the side sill, and the Z-axis is the height direction of the side sill.

[0030] As shown in FIG. 1, a side sill 100 for a vehicle according to one embodiment of the present invention may include a side sill frame 110 having a hollow portion 111, a first reinforcing frame 120 positioned in the hollow portion, and a second reinforcing frame 130 positioned in the hollow portion 111.

[0031] The first reinforcement frame 120 may be joined to the side sill frame 110 and fixed in the hollow portion 111 .

[0032] The second reinforcement frame 130 may be joined to the first reinforcement frame 120 and the side sill frame 110 and fixed in the hollow portion 111 .

[0033] The first reinforcement frame 120 and the second reinforcement frame 130 may form a closed cross section in the hollow portion 111 in a cross section in the thickness direction of the side sill frame.

[0034] As shown in FIG. 2, the side sill frame 110 may include a first side sill frame 112 to which the first reinforcement frame 120 is joined, and a second side sill frame 113 joined to the first side sill frame 112 to form a joint with the first side sill frame 112.

[0035] According to an embodiment of the present invention, at least one of the first side sill frame 112, the second side sill frame 113, the first reinforcement frame 120, and the second reinforcement frame 130 may be made of steel, thereby improving the mechanical strength of the vehicle side sill.

[0036] The second reinforcement frame 130 may be joined to an inner surface of the second side sill frame 113 .

[0037] The first and second reinforcement frames 120 and 130 may be joined to the first and second side sill frames 112 and 113, respectively, to be parallel to the X-axis.

[0038] An inner surface of the second reinforcement frame 130 may be joined to an outer surface of the first reinforcement frame 120. Thus, the first reinforcement frame 120 and the second reinforcement frame 130 may overlap in the hollow portion.

[0039] By the above-mentioned joining, the hollow portion can have a closed cross section, which improves the ability to absorb the impact energy when an impact is applied in the X-axis direction.

[0040] In addition, this can further improve the collision energy absorption capacity compared to the first side sill frame 112, the second side sill frame 113, the first reinforcing frame 120, and the second reinforcing frame 130 made of aluminum of the same weight.

[0041] Therefore, compared to a vehicle side sill made of aluminum, it is possible to realize a vehicle side sill that has improved collision energy absorption capacity while preventing an increase in the load on the entire vehicle.

[0042] In an embodiment of the present invention, the first strengthening frame 120 and the second strengthening frame 130 may be made of a material including ultra-high strength steel having a tensile strength of 980 MPa or more.

[0043] In an embodiment of the present invention, the first reinforcement frame 120 and the second reinforcement frame 130 may be made of a material including 1180 TRIP steel.

[0044] In an embodiment of the present invention, the first side sill frame 112 and the second side sill frame 113 may be made of a material including 1470 MART steel.

[0045] However, this is not necessarily limited by the present invention, and can be appropriately modified and applied within the range of steel materials.

[0046] At least one of the first side sill frame 112, the second side sill frame 113, the first reinforcing frame 120, and the second reinforcing frame 130 may be formed by form forming or crash forming a steel plate, which may contribute to reducing manufacturing costs by reducing costs for dies, etc.

[0047] 2, it is possible to easily form a closed cross section in a direction parallel to the X-axis, thereby improving the assembly and production efficiency of the vehicle side sill.

[0048] Furthermore, by configuring the cross section of the vehicle side sill as shown in FIG. 2, when the vehicle side sill receives an impact on the side, i.e., in the X-axis direction, the vehicle side sill can be made to deform uniformly in the Z-axis direction.

[0049] In addition, this can prevent the first and second strengthening frames 120 and 130 from exhibiting unevenly inclined deformation behavior in the Z-axis direction, and can allow them to undergo normal compressive deformation in the X-axis direction.

[0050] As described above, when the vehicle side sill is made of steel, its collision energy absorption capacity is at least equal to or exceeds that of a vehicle side sill made of aluminum of the same weight. Therefore, compared to when the side sill is made of aluminum, the side sill can be made lighter while still maintaining the same or higher collision energy absorption efficiency.

[0051] As shown in FIG. 3, the first strengthening frame 120 according to an embodiment of the present invention may be provided such that the cross-sectional shape in the Y-axis direction includes a concave-convex portion 140. As shown in FIG.

[0052] Also, as shown in FIG. 4, the second strengthening frame 130 according to an embodiment of the present invention may also be provided such that the cross-sectional shape in the Y-axis direction includes a concave-convex portion 140 .

[0053] The uneven portion 140 may be formed by connecting the protrusion 141 and the recess 142 in the Y-axis direction. The protrusion 141 and the recess 142 may be provided continuously over a certain section in the Y-axis direction.

[0054] The uneven portion 140 of the first reinforcement frame (120 in FIG. 3) and the second reinforcement frame (130 in FIG. 4) can increase the rigidity without increasing the weight of the first reinforcement frame 120 and the second reinforcement frame 130.

[0055] The length of the protrusion 141 and the recess 142 in the Y-axis direction and the length of the recess 142 in the Z-axis direction are not necessarily limited by the present invention, but can be determined taking into consideration at least one of the type and thickness of the steel material applied to the first reinforcement frame 120 and the second reinforcement frame 130, and can be determined according to the specifications required for the vehicle side sill.

[0056] 5, the first reinforcement frame 120 and the second reinforcement frame 130 may overlap each other in the hollow portion. The area where the first reinforcement frame 120 and the second reinforcement frame 130 overlap each other may be an overlapping portion 150. The overlapping portion 150 may be continuous in the Y-axis direction.

[0057] The overlapping portion 150 eliminates the need for a separate joining member for assembling the first and second strengthening frames 120 and 130 within the hollow portion 111, improving design freedom.

[0058] In addition, since no separate connecting member is required, this contributes to reducing the weight of the vehicle side sill.

[0059] As shown in FIG. 6, in one embodiment of the present invention, a first protrusion 141a formed on a first reinforcement frame 120 may overlap a second protrusion 141b formed on a second reinforcement frame 130, and a first recess 142a formed on the first reinforcement frame 120 may overlap a second recess 142b formed on the second reinforcement frame 130.

[0060] 7 shows a first strengthening frame 120 according to an embodiment of the present invention. The first strengthening frame 120 may be formed by bending a single steel plate. By bending a single steel plate, the mechanical strength of the first strengthening frame 120 may be further improved.

[0061] The cross-sectional shape in the thickness direction of the first reinforcement frame 120 is formed by bending both end portions 121, and may include a plurality of first lower flange portions 122 joined to the inner surface of the first side sill frame (112 in FIG. 5), a plurality of first extension portions 123 each connected to the first lower flange portions 122 and extending in the direction of the second reinforcement frame (130 in FIG. 5), and a first upper flange portion 124 connected to the plurality of first extension portions 123.

[0062] The first strengthening frame 120 may be bent so that the first extension portion 123 and the first lower flange portion 122 are disposed to intersect with each other.

[0063] The first lower flange portion 122 may be joined to an inner surface of the first side sill frame (112 in FIG. 5) by welding.

[0064] 8 shows a second strengthening frame 130 according to an embodiment of the present invention. The second strengthening frame 130 may be formed by bending a single steel plate. By bending a single steel plate, the mechanical strength of the second strengthening frame 130 may be further improved.

[0065] The second reinforcement frame 130 may be formed such that a cross-sectional shape in a thickness direction has both ends 131 facing each other in a Z-axis direction. Also, the second reinforcement frame 130 may include a plurality of second extension parts 132 extending in a direction of the second side sill frame (113 in FIG. 5), and a second upper flange part 133 connected to the plurality of second extension parts 132 and joined to an inner surface of the second side sill frame (113 in FIG. 5).

[0066] In one embodiment of the present invention, the second upper flange portion 133 may be flat. Accordingly, when an adhesive is applied to the second upper flange portion 133 for bonding with the second side sill frame (113 in FIG. 5), the adhesive strength of the second upper flange portion 133 may be improved, and the convenience of bonding and assembly operations may be improved.

[0067] The second extension 132 may be joined to the first extension (123 in FIG. 7), and the end 131 of the second reinforcement frame 130 may be on the first extension (123 in FIG. 7).

[0068] In one embodiment of the present invention, the second extension 132 may be joined to the first extension (123 in FIG. 7) by welding.

[0069] In addition, in one embodiment of the present invention, the second extension portion 132 may be provided to have a step in the X-axis direction. In addition, the width between the plurality of second extension portions 132 may be widest at a width D from one end to the other end. This allows the second reinforcement frame 130 to be easily stacked on the first reinforcement frame 120, improving the convenience of assembly.

[0070] 9 shows the deformation analysis results at the initial stage of a collision in a collision test of a vehicle side sill according to an embodiment of the present invention. An impact is applied in the direction from the first side sill frame 112 to the second side sill frame 113.

[0071] Referring to FIG. 9, it can be seen that at the initial stage of a collision, the first side sill frame 112 and the second side sill frame 113 are compressed in the X-axis direction while being stretched in the Z-axis direction, and are deformed, and the first reinforcement frame 120 and the second reinforcement frame 130 are also compressed in the X-axis direction.

[0072] At this time, it can be seen that the deformation of the first reinforcement frame 120 and the second reinforcement frame 130 is not biased to one side, but is uniformly distributed in the Z-axis direction.

[0073] 10 shows the results of deformation analysis at a later stage of the collision. It can be seen that the first side sill frame 112 and the second side sill frame 113 are further compressed in the X-axis direction and further stretched in the Z-axis direction.

[0074] At this time, it can be seen that the deformations of the first reinforcement frame 120 and the second reinforcement frame 130 are still uniformly distributed in the Z-axis direction.

[0075] 11 shows a cross section of a conventional vehicle side sill 10. The conventional vehicle side sill may include a plurality of side sill frames 11, 12 and reinforcing members 13, 14, 15 provided inside the side sill frames 11, 12.

[0076] A load-displacement diagram of the conventional vehicle side sill 10 and a vehicle side sill according to an embodiment of the present invention (100 in FIG. 1) is shown in FIG 12. In FIG 12, the load-displacement value of the vehicle side sill (100 in FIG. 1) shown in FIG 1 is indicated by a first value L1, and the load-displacement value of the vehicle side sill (10 in FIG. 11) shown in FIG 11 is indicated by a second value L2.

[0077] With reference to the first value L1 and the second value L2, it can be seen that the displacement of the vehicle side sill shown in FIG. 1 (100 in FIG. 1) is relatively smaller under the same load than the vehicle side sill shown in FIG. 11 (10 in FIG. 11).

[0078] In addition, in the case of the second value L2, the impact absorbing capacity drops rapidly when the displacement is 60 mm or more, which corresponds to the later stage of the collision.

[0079] In the case of the conventional vehicle side sill 10 shown in Fig. 11, the first reinforcing member 14 and the second reinforcing member 13 are joined together. Therefore, when a collision occurs, as the second reinforcing member 13 is deformed, the first reinforcing member 14 is deformed together with the second reinforcing member 13 without independently exhibiting a stable crushing behavior. For this reason, in the case of the second value L2, the impact absorbing capacity drops sharply at a displacement of 60 mm or more, which corresponds to the later stage of the collision.

[0080] On the other hand, in the case of the first value L1, it is found that the impact is absorbed stably even in the later stages of the collision.

[0081] In the case of the vehicle side sill 100 shown in FIG. 1, as shown in FIG. 9 and FIG. 10, when a collision occurs, the deformation characteristics of the first reinforcement frame 120 show stable crushing behavior, so that the impact absorption ability is maintained to a certain extent stably even when the displacement is 60 mm or more, which corresponds to the later stage of the collision.

[0082] The above description has been given of one embodiment of the present invention, but it will be apparent to those skilled in the art that the scope of the present invention is not limited thereto, and that various modifications and variations are possible without departing from the technical idea of ​​the present invention as described in the claims. [Explanation of symbols]

[0083] 110 Side sill frame 111 Hollow section 112 1st side sill frame 113 2nd side sill frame 120 first reinforcement frame 122 first lower flange portion 123 First extension portion 124 First upper flange portion 130 second reinforcement frame 132 second extension 133 second upper flange portion 140 uneven portion 141 protrusion 142 recess 150 Overlap

Claims

1. A side sill frame formed to have a hollow portion; A first reinforcing frame disposed in the hollow portion and joined to the side sill frame; and a second reinforcing frame disposed in the hollow portion and joined to the first reinforcing frame and the side sill frame; The first reinforcement frame and the second reinforcement frame are The side sill frame is disposed in the hollow portion so as to form a closed cross section in the hollow portion in a cross section in a thickness direction of the side sill frame, The side sill frame is a first side sill frame to which the first reinforcing frame is joined; and a second side sill frame joined to the first side sill frame and having the second reinforcing frame joined to its inner surface; The cross-sectional shape of the first reinforcement frame in the thickness direction is a plurality of first lower flange portions each having both ends bent and joined to an inner surface of the first side sill frame; a plurality of first extensions respectively connected to the plurality of first lower flange portions and extending in a direction toward the second reinforcement frame; and a first upper flange portion connected to the first extension portions; The cross-sectional shape of the second reinforcement frame in the thickness direction is a plurality of second extensions joined to the first extension and extending in a direction toward the second side sill frame; and a second upper flange portion connected to the second extension portion and joined to an inner surface of the second side sill frame; A side sill for a vehicle, wherein an end of the second extension portion is located on the first extension portion.

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

3. The first reinforcement frame and the second reinforcement frame are The vehicle side sill according to claim 2 , wherein a cross-sectional shape of the side sill frame in a longitudinal direction includes an uneven portion.

4. The vehicle side sill according to claim 3 , wherein the first reinforcement frame and the second reinforcement frame overlap at the hollow portion.

5. The uneven portion is The vehicle side sill according to claim 4 , wherein the protrusion and the recess are formed continuously in the longitudinal direction of the side sill frame.

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

7. The second upper flange portion is The vehicle side sill according to claim 1 , which is flat.

8. The cross-sectional shape of the second reinforcement frame in the thickness direction is The vehicle side sill according to claim 1 , wherein a step is formed in the second extension portion.

9. A width between the plurality of second extension portions in a cross section in a thickness direction of the second reinforcement frame is The side sill for a vehicle according to claim 8 , wherein a width from an end of the second extension portion on one side to an end of the second extension portion on the other side is widest.

10. The first lower flange portion is welded to the first side sill frame, the second extension is welded to the first extension, The vehicle side sill according to claim 1 , wherein the second upper flange portion is joined to the second side sill frame by an adhesive.

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