Vehicle side sill

Abstract

The present invention provides a side sill for a vehicle, comprising: a side sill frame including a hollow portion; and a reinforcing frame disposed inside the hollow portion in a longitudinal direction of the side sill frame; the reinforcing frame is continuous in the longitudinal direction of the side sill frame, has unit sections whose heights vary, and has an upper surface and a lower surface spaced apart from the side sill frame.

Description

[Technical field]

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

[0002] The material described in this section is merely intended to provide background information for the present invention and may not constitute prior art.

[0003] Vehicle side sills serve to protect passengers by absorbing collision energy during a side collision.

[0004] 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.

[0005] 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.

[0006] 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]

[0007] [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]

[0008] An object of the present invention is to improve the collision energy absorption efficiency of a side sill and to achieve weight reduction.

[0009] An object of the present invention is to increase the rigidity of a side sill and reduce manufacturing costs. [Means for solving the problem]

[0010] As one aspect of achieving the above object, the present invention provides a side sill for a vehicle, comprising: a side sill frame including a hollow portion; and a reinforcing frame disposed inside the hollow portion in a longitudinal direction of the side sill frame; the reinforcing frame is continuous in the longitudinal direction of the side sill frame, has unit sections whose heights vary, and has an upper surface and a lower surface spaced apart from the side sill frame.

[0011] The unit section may include a first planar portion positioned parallel to the longitudinal direction of the side sill frame; an inclined portion connected to the first planar portion and disposed at an angle; and a second planar portion connected to the inclined portion and located lower than the first planar portion.

[0012] The inclined portion may include a first inclined portion connecting from the first planar portion to the second planar portion and arranged with a downward incline; and a second inclined portion connecting from the second planar portion to the first planar portion and arranged with an upward incline.

[0013] The vehicle may include a first side sill frame to which one side of the reinforcement frame is joined; and a second side sill frame to which the other side of the reinforcement frame is joined and joined to the first side sill frame; and the first planar portion and the second planar portion may be arranged to face a joint between the first side sill frame and the second side sill frame.

[0014] At least one of the first planar portion and the second planar portion may include an uneven portion.

[0015] The first planar portion and the second planar portion may have a length in a length direction of the side sill frame that is any one value between 40 mm and 70 mm.

[0016] An angle formed between an extension of the first flat portion and the inclined portion and an angle formed between an extension of the second flat portion and the inclined portion may be any one value between 45° and 75°.

[0017] The unit section may include a third flat portion located parallel to the longitudinal direction of the side sill frame; a third inclined portion connected to the third flat portion and disposed with an upward inclination; and a fourth inclined portion connected to the third inclined portion and disposed with a downward inclination.

[0018] The unit section may include a fourth flat portion located parallel to the longitudinal direction of the side sill frame; a fifth inclined portion connected to the fourth flat portion and arranged with a downward inclination; and a sixth inclined portion connected to the fifth inclined portion and arranged with an upward inclination.

[0019] The unit section may include: a seventh inclined portion disposed with an upward incline; and an eighth inclined portion connected to the seventh inclined portion and disposed with a downward incline.

[0020] The seventh inclined portion and the eighth inclined portion may have a flat plate shape.

[0021] The seventh inclined portion and the eighth inclined portion may have a curved plate shape.

[0022] The unit section includes a first unit section disposed on the upper side in the height direction of the side sill frame and a second unit section disposed below the first unit section, the first unit section including a fifth planar portion disposed parallel to the length direction of the side sill frame, a ninth inclined portion connected from the fifth planar portion and disposed with an upward inclination, and a tenth inclined portion connected from the ninth inclined portion and disposed with a downward inclination, and the second unit section includes a sixth planar portion disposed parallel to the length direction of the side sill frame, an eleventh inclined portion connected from the sixth planar portion and disposed with a downward inclination, and a twelfth inclined portion connected from the eleventh inclined portion and disposed with an upward inclination.

[0023] The fifth flat portion and the sixth flat portion may be disposed in contact with each other.

[0024] The unit section includes a first unit section disposed on the upper side in the height direction and a second unit section disposed below the first unit section, the first unit section includes a seventh planar portion positioned parallel to the length direction of the side sill frame, a thirteenth inclined portion connected to the seventh planar portion and inclined upward, an eighth planar portion connected to the thirteenth inclined portion and located lower than the seventh planar portion, and a fourteenth inclined portion connected to the eighth planar portion and inclined downward, and the second unit section includes a ninth planar portion positioned parallel to the length direction of the side sill frame, a fifteenth inclined portion connected to the ninth planar portion and inclined downward, a tenth planar portion connected to the fifteenth inclined portion and located lower than the ninth planar portion, and a sixteenth inclined portion connected to the tenth planar portion and inclined upward.

[0025] The seventh and ninth flat portions may be disposed in contact with each other.

[0026] The unit section may include a first unit section disposed on the upper side in the height direction of the side sill frame; and a second unit section disposed below the first unit section; the first unit section may include a 17th inclined portion disposed with an upward incline; and an 18th inclined portion connected to the 17th inclined portion and disposed with a downward incline; and the second unit section may include a 19th inclined portion disposed with a downward incline; and a 20th inclined portion connected to the 19th inclined portion and disposed with an upward incline.

[0027] At least one of the side sill frame and the reinforcing frame may be made of steel.

[0028] The reinforcing frame may be made of a single steel plate.

[0029] The thickness of the reinforcing frame may be any one value between 1.8 mm and 2.2 mm.

[0030] The reinforcing frame may have a tensile strength of 1180 MPa or more and a yield strength of any one of 850 MPa to 1060 MPa. Effect of the Invention

[0031] 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.

[0032] 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]

[0033] [Figure 1] 1 is a perspective view of a vehicle side sill according to a first embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view taken along the line II' in FIG. 1. [Diagram 3] FIG. 6 is a cross-sectional view of a reinforcing frame according to a second embodiment of the present invention. [Figure 4] 1 is a cross-sectional view of a typical vehicle side sill. [Diagram 5] 5 is a load-displacement diagram of the vehicle side sill of FIG. 1 and the vehicle side sill of FIG. 4. [Figure 6] 1. FIG. 4 is a cross-sectional view of a vehicle side sill according to a third embodiment of the present invention taken along line II' in FIG. [Figure 7] 1. FIG. 4 is a cross-sectional view of a vehicle side sill according to a fourth embodiment of the present invention taken along line II' in FIG. [Figure 8] 1. FIG. 4 is a cross-sectional view of a vehicle side sill according to a fifth embodiment of the present invention taken along line II' in FIG. [Figure 9] 1. FIG. 4 is a cross-sectional view of a vehicle side sill according to a sixth embodiment of the present invention taken along line II' in FIG. [Figure 10] 1. FIG. 4 is a cross-sectional view of a vehicle side sill according to a seventh embodiment of the present invention taken along line II' in FIG. [Figure 11] 1. FIG. 2 is a cross-sectional view of a vehicle side sill according to an eighth embodiment of the present invention taken along line II' in FIG. [Figure 12] 1. FIG. 13 is a cross-sectional view of a vehicle side sill according to a ninth embodiment of the present invention taken along line II' in FIG. [Figure 13] 13 is a cross-sectional view of a vehicle side sill according to a tenth embodiment of the present invention taken along line II' in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] 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 numbers.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] FIG. 1 is a perspective view of a vehicle side sill according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II' in FIG.

[0039] As shown in FIG. 1, a vehicle side sill 100 according to a first embodiment of the present invention may include a side sill frame 110 having a hollow portion 113 , and a reinforcing frame 120 positioned in the hollow portion 113 .

[0040] Both sides of the reinforcement frame 120 may be coupled to the side sill frame 110, and may be continuously present in a predetermined section in the Y-axis direction in the hollow portion 113 of the side sill frame 110.

[0041] The reinforcing frame 120 is continuous in the length direction of the side sill frame 110 and has unit sections whose heights vary, and the upper and lower surfaces of the reinforcing frame 120 may be spaced apart from the side sill frame 110. This is to simultaneously achieve improved collision energy absorption efficiency and weight reduction.

[0042] Specifically, the reinforcing frame (120 in FIG. 1) may be spaced apart from the upper and lower surfaces of the first side sill frame (111 in FIG. 1) and the upper and lower surfaces of the second side sill frame (112 in FIG. 1).

[0043] Such a reinforced frame can improve the ability to absorb collision energy when an impact is applied to the side sill frame (110 in FIG. 1) in the X-axis direction (X in FIG. 1).

[0044] By disposing the reinforcement frame 120 so as to be spaced apart from the upper and lower surfaces of the side sill frame 110, when an impact is applied in the X-axis direction, the reinforcement frame 120 can be disposed in the central region in the Z-axis direction so as to realize the maximum deformation load. This has the effect of improving the efficiency of absorbing collision energy while maximizing the weight reduction of the vehicle.

[0045] The strengthening frames 120 may be arranged in a staggered manner in the Y-axis direction in the hollow portion 113 .

[0046] In the first embodiment of the present invention, the side sill frame may include a first side sill frame to which one side of the strengthening frame 120 is joined, and a second side sill frame to which the other side of the strengthening frame is joined.

[0047] The first side sill frame and the second side sill frame may be joined to each other to form a joint 114 .

[0048] FIG. 2 shows a cross-sectional shape of the reinforcing frame (120 in FIG. 1) according to the first embodiment of the present invention in the length direction of the side sill frame, that is, in the Y-axis direction.

[0049] The cross-sectional shape of the reinforcement frame may include a first planar portion 121a positioned parallel to the longitudinal direction of the side sill frame, an inclined portion 122 connected to the first planar portion 121a and arranged at an angle, and a second planar portion 121b connected to the inclined portion 122.

[0050] The second flat surface portion 121b can be located lower than the first flat surface portion 121a in the Z-axis direction.

[0051] The first and second planar portions 121a and 121b may be provided in the hollow portion (113 in FIG. 1) to face a joint portion (114 in FIG. 1) of a first side sill frame (111 in FIG. 1) and a second side sill frame (112 in FIG. 1). Here, the term "face" means that the first and second planar portions 121a and 121b are disposed so that the joint portion 114 faces each other.

[0052] The first flat portion 121a may be disposed to face a joint portion (114 in FIG. 1) between the first side sill frame (111 in FIG. 1) and the second side sill frame (112 in FIG. 1) disposed on the upper side. The second flat portion 121b may be disposed to face a joint portion (114 in FIG. 1) between the first side sill frame (111 in FIG. 1) and the second side sill frame (112 in FIG. 1) disposed on the lower side.

[0053] The joint portion 114 and the first flat portion 121a arranged on the upper side may be arranged at a distance from each other while facing each other, and the joint portion 114 and the second flat portion 121b arranged on the lower side may be arranged at a distance from each other while facing each other.

[0054] The first and second planar portions 121a and 121b may be positioned in parallel to a Y-axis direction, and the inclined portion 122 may connect the first and second planar portions 121a and 121b.

[0055] The inclined portion 122 may include a first inclined portion 122a and a second inclined portion 122b. The first inclined portion 122a may be connected from the first flat portion 121a to the second flat portion 121b and may be disposed with a downward inclination, and the second inclined portion 122b may be connected from the second flat portion 121b to the first flat portion 121a and may be disposed with an upward inclination.

[0056] The first flat portion 121a, the second flat portion 121b, and the inclined portion 122 may be continuously present in the Y-axis direction in the hollow portion (113 in FIG. 1). A unit section may be composed of the first flat portion 121a, the first inclined portion 122a, the second flat portion 121b, and the second inclined portion 122b. A plurality of unit sections may be repeated in the Y-axis direction.

[0057] According to an embodiment of the present invention, the first planar portion 121a and the second planar portion 121b may have the same length in the Y-axis direction.

[0058] Furthermore, according to the first embodiment of the present invention, the length of the first flat portion 121a and the second flat portion 121b in the Y-axis direction may be any one value between 40 mm and 70 mm.

[0059] If the length in the Y-axis direction of the first planar portion 121a and the second planar portion 121b is less than 40 mm, the period of the repeating pattern of the unit section of the reinforcing frame 120 will be shortened, which may increase the amount of material used and increase the weight, which may have a negative impact on weight reduction.

[0060] If the length of the first planar portion 121a and the second planar portion 121b in the Y-axis direction exceeds 70 mm, the resistance to deformation of the first planar portion 121a and the second planar portion 121b may decrease, and since the period of the repeating pattern of the unit section of the reinforcement frame 120 becomes longer, the resistance portion that resists deformation decreases, which may result in a decrease in the efficiency of collision energy absorption.

[0061] Furthermore, according to the first embodiment of the present invention, the angle formed by the extension line of the second flat portion 121b and the inclined portion 122 may be any one value between 45° and 75°.

[0062] This can be similarly applied to the first flat portion 121a, and the angle θ formed by an extension line of the first flat portion 121a and the inclined portion 122 can also be any one value between 45° and 75°.

[0063] When the angle θ formed by the extension line of the second flat portion 121b and the inclined portion 122 is less than 45°, the period of the repeating pattern of the unit section of the reinforcement frame 120 becomes longer, which may cause a decrease in the collision energy absorption efficiency due to a decrease in the resistance portion that resists deformation. Similarly, when the angle θ formed by the extension line of the first flat portion 121a and the inclined portion 122 is less than 45°, a decrease in the collision energy absorption efficiency may occur.

[0064] If the angle θ formed by the extension line of the second flat portion 121b and the inclined portion 122 exceeds 75 degrees, the period of the repeating pattern of the unit section of the reinforced frame 120 becomes shorter, which may adversely affect weight reduction by increasing the amount of material used and increasing the weight. This may also be adversely affected in the case where the angle θ formed by the extension line of the first flat portion 121a and the inclined portion 122 exceeds 75 degrees.

[0065] Meanwhile, the length of the inclined portion 122 in the Z-axis direction can be appropriately selected and applied depending on the cross-sectional height of a seat cross member of a vehicle to which the vehicle side sill will be applied and the mounting structure of a battery.

[0066] According to the present invention, the collision energy absorption capacity of the reinforced frame relative to its weight can be maximized.

[0067] 3 shows a cross section of a reinforcement frame (120 in FIG. 1) according to a second embodiment of the present invention. As shown in FIG. 3, at least one of the first flat portion 121a and the second flat portion 121b of the reinforcement frame according to another embodiment of the present invention may include a concave-convex portion 130.

[0068] The uneven portion 130 may include a protruding portion 131 protruding in the direction in which the Z axis increases and a recessed portion 132 formed in a recessed shape based on the direction in which the Z axis increases.

[0069] The protrusion 131 may be formed on the second planar portion 121b, and the recess 132 may be formed on the first planar portion 121a. However, this is not necessarily limited by the present invention, and the protrusion 131 may be formed on the first planar portion 121a, and the recess 132 may be formed on the second planar portion 121b. Also, the first planar portion 121a and the second planar portion 121b may have both a protrusion and a recess.

[0070] The protrusions 131 and the recesses 132 can further increase the rigidity of the reinforcing frame (120 in FIG. 1).

[0071] The protrusion 131 and the recess 132 can be formed by bending the reinforcing frame (120 in FIG. 1).

[0072] The protrusions 131 and the recesses 132 can increase the rigidity of the strengthening frame (120 in FIG. 1) without increasing the weight of the strengthening frame.

[0073] On the other hand, FIG. 4 shows a cross section of a conventional vehicle side sill 10, and FIG. 5 shows a load-displacement diagram of the vehicle side sill of FIG. 4 (10 in FIG. 4) and the vehicle side sill of FIG. 1 (100 in FIG. 1).

[0074] In FIG. 5, the length of the first flat portion (121a in FIG. 2) of the reinforced frame (120 in FIG. 1) of the vehicle side sill (100 in FIG. 1) according to the present invention is set to 50 mm, the length of the second flat portion (121b in FIG. 2) is set to 50 mm, the angle θ formed by the extension line of the second flat portion (121b in FIG. 2) and the inclined portion (122 in FIG. 2) and the angle θ formed by the extension line of the first flat portion (121a in FIG. 2) and the inclined portion (122 in FIG. 2) are set to 51.2°, and the thickness of the reinforced frame (120 in FIG. 1) is set to 2.0 mm.

[0075] In FIG. 5, the load-displacement value of the vehicle side sill (100 in FIG. 1) according to the present invention shown in FIG. 1 is indicated as a first value L1, and the load-displacement value of the vehicle side sill (10 in FIG. 4) shown in FIG. 4 is indicated as a second value L2.

[0076] 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 than that of the conventional vehicle side sill shown in FIG. 4 (10 in FIG. 4) under the same load.

[0077] In addition, the cross-sectional structure of the vehicle side sill (100 in FIG. 1) according to the present invention is simpler than that of a typical vehicle side sill (10 in FIG. 4), and the number of components of the vehicle side sill (100 in FIG. 1) according to the present invention is fewer than that of a typical vehicle side sill (10 in FIG. 4). Considering this, it can be seen that the vehicle side sill of the present invention has a significantly improved impact energy absorption ability compared to a typical vehicle side sill.

[0078] In addition, according to the test results, the side sill frame (110 in FIG. 1) of the vehicle side sill (100 in FIG. 1) according to the present invention has a collision energy absorption capacity per unit weight (internal energy ratio (KJ / kg) per 1 kg) of 82.9% when its weight is 15.8 kg, while the side sill frame (11, 12 in FIG. 4) of a conventional vehicle side sill (10 in FIG. 4) has a collision energy absorption capacity per unit weight (internal energy ratio (KJ / kg) per 1 kg) of 61.7% when its weight is 22.1 kg. Therefore, it can be seen that the vehicle side sill according to the present invention has a significantly higher collision energy absorption capacity while being lighter than the conventional vehicle side sill.

[0079] According to the present invention, it is possible to reduce the weight of the vehicle side sill while improving its collision energy absorbing ability.

[0080] In addition, by arranging the reinforcing frames at optimal positions inside the side sill frame, it is possible to realize maximum impact energy absorption performance with a minimum number of reinforcing frames and a minimum weight of the reinforcing frames.

[0081] Hereinafter, vehicle side sills according to third to tenth embodiments of the present invention will be described with reference to FIGS.

[0082] Here, the vehicle side sills according to the third to tenth embodiments of the present invention differ only in the configuration of the reinforcing frame, and the remaining components can be the same as the configuration of the vehicle side sill of the first embodiment described above (see Figures 1 and 2).

[0083] Therefore, it goes without saying that the various embodiments of the components such as the side sill frame included in the vehicle side sill described above can be applied to the third to tenth embodiments of the present invention.

[0084] FIG. 6 is a cross-sectional view of a vehicle side sill according to a third embodiment of the present invention taken along line II' in FIG.

[0085] The unit section 120U according to the third embodiment of the present invention may include a third flat portion 121c, a third inclined portion 122c, and a fourth inclined portion 122d. A plurality of unit sections 120U may be repeated in the Y-axis direction. The third flat portion 121c, the third inclined portion 122c, and the fourth inclined portion 122d may be continuously present in the hollow portion 113 in the Y-axis direction.

[0086] The third flat portion 121c may be positioned parallel to the longitudinal direction of the side sill frame 110. The third inclined portion 122c may be connected to the third flat portion 121c and disposed with an upward inclination. The fourth inclined portion 122d may be connected to the third inclined portion 122c and disposed with a downward inclination. As an example, the third inclined portion 122c and the fourth inclined portion 122d may have the same length.

[0087] The third flat portion 121c may have a length in the Y-axis direction of 40 mm or more and 70 mm or less, and the effect of this may be the same as that described in the first embodiment of the present invention.

[0088] The angle θ formed by an extension line of the third flat portion 121c and the third inclined portion 122c may be any one value between 45° and 75°. The angle θ formed by an extension line of the third flat portion 121c and the fourth inclined portion 122d may be any one value between 45° and 75°. The effect of this may be the same as the effect described above in the first embodiment of the present invention.

[0089] FIG. 7 is a cross-sectional view of a vehicle side sill according to a fourth embodiment of the present invention taken along line II' in FIG.

[0090] The unit section 120U according to the fourth embodiment of the present invention may include a fourth flat portion 121d, a fifth inclined portion 122e, and a sixth inclined portion 122f. A plurality of unit sections 120U may be repeated in the Y-axis direction. The fourth flat portion 121d, the fifth inclined portion 122e, and the sixth inclined portion 122f may be continuously present in the hollow portion 113 in the Y-axis direction.

[0091] The fourth flat portion 121d may be positioned parallel to the longitudinal direction of the side sill frame 110. The fifth inclined portion 122e may be connected to the fourth flat portion 121d and disposed in a downward inclined manner. The sixth inclined portion 122f may be connected to the fifth inclined portion 122e and disposed in a upward inclined manner.

[0092] The fourth flat portion 121d may have a length in the Y-axis direction of 40 mm or more and 70 mm or less, and the effect of this may be the same as that described in the first embodiment of the present invention.

[0093] The angle θ formed by an extension of the third flat portion 121c and the fifth inclined portion 122e may be any one value between 45° and 75°. The angle θ formed by an extension of the fourth flat portion 121d and the sixth inclined portion 122f may be any one value between 45° and 75°. The effect of this may be the same as that described in the first embodiment of the present invention.

[0094] FIG. 8 is a cross-sectional view of a vehicle side sill according to a fifth embodiment of the present invention, taken along the line II' in FIG. 1, and FIG. 9 is a cross-sectional view of a vehicle side sill according to a sixth embodiment of the present invention, taken along the line II' in FIG. 1.

[0095] The unit section 120U according to the fifth and sixth embodiments of the present invention may include a seventh inclined portion 122g and an eighth inclined portion 122h. The seventh inclined portion 122g may be disposed with an upward inclination. The eighth inclined portion 122h may be connected to the seventh inclined portion 122g and disposed with a downward inclination. As an example, the seventh inclined portion 122g and the eighth inclined portion 122h may have the same length.

[0096] Referring to FIG. 8, the seventh inclined portion 122g and the eighth inclined portion 122h may have a flat plate shape.

[0097] Referring to FIG. 9, the seventh inclined portion 122g and the eighth inclined portion 122h may have a curved plate shape.

[0098] FIG. 10 is a cross-sectional view of a vehicle side sill according to a seventh embodiment of the present invention taken along line II' in FIG.

[0099] The unit section 120U of the seventh embodiment of the present invention may include a first unit section 120U-1 and a second unit section 120U-2. The first unit section 120U-1 may be disposed on the upper side in the height direction of the side sill frame 110, and the second unit section 120U-2 may be disposed on the lower side of the first unit section 120U-1.

[0100] The first unit section 120U-1 may include a fifth flat portion 121e, a ninth inclined portion 122i, and a tenth inclined portion 122j.

[0101] The fifth flat portion 121e may be positioned parallel to the longitudinal direction of the side sill frame 110. The ninth inclined portion 122i may be connected to the fifth flat portion 121e and disposed inclined upward. The tenth inclined portion 122j may be connected to the ninth inclined portion 122i and disposed inclined downward. As an example, the ninth inclined portion 122i and the tenth inclined portion 122j may have the same length.

[0102] The second unit section 120U-2 may include a sixth flat portion 121f, an eleventh inclined portion 122k, and a twelfth inclined portion 122l.

[0103] The sixth flat portion 121f may be positioned parallel to the longitudinal direction of the side sill frame 110. The eleventh inclined portion 122k may be connected to the sixth flat portion 121f and disposed inclined downward. The twelfth inclined portion 122l may be connected to the eleventh inclined portion 122k and disposed inclined upward. As an example, the eleventh inclined portion 122k and the twelfth inclined portion 122l may have the same length.

[0104] The fifth flat portion 121e and the sixth flat portion 121f may be disposed in contact with each other. For example, the fifth flat portion 121e and the sixth flat portion 121f may be joined to each other by an adhesive or a welding method.

[0105] When an impact is applied in the X-axis direction or the like, deformation may occur in the first unit section 120U-1 and the second unit section 120U-2 of the reinforcement frame 120. At this time, the fifth flat surface portion 121e of the first unit section 120U-1 and the sixth flat surface portion 121f of the second unit section 120U-2 are disposed to be in contact with each other, so that the first unit section 120U-1 and the second unit section 120U-2 can correct each other's deformation, thereby improving the collision energy absorption efficiency of the vehicle side sill.

[0106] FIG. 11 is a cross-sectional view of a vehicle side sill according to an eighth embodiment of the present invention taken along the line II' in FIG.

[0107] The unit section 120U of the eighth embodiment of the present invention may include a first unit section 120U-1 and a second unit section 120U-2. The first unit section 120U-1 may be disposed on the upper side in the height direction of the side sill frame 110, and the second unit section 120U-2 may be disposed on the lower side of the first unit section 120U-1.

[0108] The first unit section 120U-1 may include a seventh flat portion 121g, a thirteenth inclined portion 122m, an eighth flat portion 121h, and a fourteenth inclined portion 122n.

[0109] The seventh flat portion 121g may be positioned parallel to the length direction of the side sill frame 110. The thirteenth inclined portion 122m may be connected to the seventh flat portion 121g and disposed in an upwardly inclined manner. The eighth flat portion 121h may be connected to the thirteenth inclined portion 122m and may be located lower than the seventh flat portion 121g. The fourteenth inclined portion 122n may be connected to the eighth flat portion 121h and disposed in an upwardly inclined manner.

[0110] The seventh flat portion 121g and the eighth flat portion 121h may be positioned parallel to the Y-axis direction, and the seventh flat portion 121g may be located lower than the eighth flat portion 121h in the Z-axis direction.

[0111] The second unit section 120U-2 may include a ninth flat portion 121i, a fifteenth inclined portion 122o, a tenth flat portion 121j, and a sixteenth inclined portion 122p.

[0112] The ninth flat portion 121i may be positioned parallel to the longitudinal direction of the side sill frame 110. The fifteenth inclined portion 122o may be connected to the ninth flat portion 121i and disposed in a downward inclined position. The tenth flat portion 121j may be connected to the fifteenth inclined portion 122o and may be located lower than the ninth flat portion 121i. The sixteenth inclined portion 122p may be connected to the tenth flat portion 121j and disposed in a upward inclined position.

[0113] The ninth flat portion 121i and the tenth flat portion 121j may be positioned parallel to the Y-axis direction, and the tenth flat portion 121j may be located lower than the ninth flat portion 121i in the Z-axis direction.

[0114] The seventh flat portion 121g and the ninth flat portion 121i may be disposed in contact with each other. For example, the seventh flat portion 121g and the ninth flat portion 121i may be joined to each other by an adhesive or a welding method.

[0115] When an impact is applied in the X-axis direction or the like, deformation may occur in the first unit section 120U-1 and the second unit section 120U-2 of the reinforcing frame 120. At this time, the seventh flat surface portion 121g of the first unit section 120U-1 and the ninth flat surface portion 121i of the second unit section 120U-2 are disposed to be in contact with each other, so that the first unit section 120U-1 and the second unit section 120U-2 can correct each other's deformation, thereby improving the collision energy absorption efficiency of the vehicle side sill.

[0116] FIG. 12 is a cross-sectional view of a vehicle side sill according to a ninth embodiment of the present invention, taken along the line II' in FIG. 1, and FIG. 13 is a cross-sectional view of a vehicle side sill according to a tenth embodiment of the present invention, taken along the line II' in FIG. 1.

[0117] The unit section 120U in the ninth and tenth embodiments of the present invention may include a first unit section 120U-1 and a second unit section 120U-2. The first unit section 120U-1 may be disposed on the upper side in the height direction of the side sill frame 110, and the second unit section 120U-2 may be disposed on the lower side of the first unit section 120U-1.

[0118] The first unit section 120U-1 may include a 17th inclined portion 122q and an 18th inclined portion 122r. The 17th inclined portion 122q may be disposed with an upward inclination. The 18th inclined portion 122r may be connected to the 17th inclined portion 122q and disposed with a downward inclination. For example, the 17th inclined portion 122q and the 18th inclined portion 122r may have the same length.

[0119] The second unit section 120U-2 may include a 19th inclined portion 122s and a 20th inclined portion 122t. The 19th inclined portion 122s may be disposed with a downward inclination. The 20th inclined portion 122t may be connected to the 19th inclined portion 122s and disposed with an upward inclination. For example, the 19th inclined portion 122s and the 20th inclined portion 122t may have the same length.

[0120] Referring to Fig. 12, the seventeenth inclined portion 122q, the eighteenth inclined portion 122r, the nineteenth inclined portion 122s, and the twentieth inclined portion 122t may have a flat plate shape. Referring to Fig. 13, the seventeenth inclined portion 122q, the eighteenth inclined portion 122r, the nineteenth inclined portion 122s, and the twentieth inclined portion 122t may have a curved plate shape.

[0121] A lower intersection point where the 17th inclined portion 122q and the 18th inclined portion 122r of the first unit section 120U-1 intersect and an upper intersection point where the 19th inclined portion 122s and the 20th inclined portion 122t of the second unit section 120U-2 intersect may be disposed adjacent to each other. The lower intersection point of the first unit section 120U-1 and the upper intersection point of the second unit section 120U-2 may be joined to each other by an adhesive or a welding method.

[0122] In the first to tenth embodiments of the present invention, at least one of the side sill frame 110 and the reinforcing frame 120 may be made of steel. This can improve the mechanical strength of the vehicle side sill. Also, this can improve the collision energy absorption capacity more than a vehicle side sill (not shown) made of aluminum of the same weight.

[0123] Therefore, it is possible to realize a vehicle side sill having improved collision energy absorption capacity compared to a vehicle side sill made of aluminum, while preventing an increase in the load of the entire vehicle on the vehicle side sill made of aluminum.

[0124] In the first to tenth embodiments of the present invention, the thickness of the strengthening frame 120 may be any one value between 1.8 mm and 2.2 mm.

[0125] If the thickness of the reinforced frame 120 is less than 1.8 mm, the performance of the collision energy absorption efficiency may be reduced due to a decrease in resistance to deformation of the reinforced frame 120. If the thickness of the reinforced frame 120 exceeds 2.2 mm, there is a problem that the effect of weight reduction is reduced due to an increase in the weight of the reinforced frame 120.

[0126] In the first to tenth embodiments of the present invention, the strengthening frame 120 may be made of a material including ultra-high strength steel having a tensile strength of 980 MPa or more.

[0127] In the first to tenth embodiments of the present invention, the strengthening frame 120 may be made of a material including 1180 TRIP steel.

[0128] In the first to tenth embodiments of the present invention, the first side sill frame 111 and the second side sill frame 112 may be made of a material including 1470 MART steel.

[0129] In addition, in the first to tenth embodiments of the present invention, the strengthening frame 120 may be formed by bending a single steel plate. This can further improve the mechanical strength of the strengthening frame 120 and contribute to reducing the manufacturing cost.

[0130] In the first to tenth embodiments of the present invention, the reinforcing frame 120 may have a tensile strength of 1180 MPa or more and a yield strength of any one of 850 MPa or more and 1060 MPa or less.

[0131] When a vehicle side sill is formed from steel as described above, its collision energy absorption capacity can be at least equal to or exceed the collision energy absorption capacity of a vehicle side sill made of aluminum of the same weight.

[0132] Therefore, it is possible to reduce the weight of the side sill compared to when the side sill is made of aluminum, while still improving the collision energy absorption efficiency to the same level or higher.

[0133] In the first to tenth embodiments of the present invention, one side of the reinforcing frame 120 may be arc-welded to the first side sill frame 111. Furthermore, the other side of the reinforcing frame 120 may be bonded to the second side sill frame 112 by an adhesive. This can improve the convenience of the manufacturing process of the vehicle side sill.

[0134] According to the vehicle side sill of the present invention, when a load is applied in the X-axis direction, the vehicle side sill can be easily compressed and deformed in the X-axis direction, improving the shock absorbing ability, thereby minimizing the transmission of the shock to the space where the vehicle battery is located (not shown) and the space where the passengers are located.

[0135] 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]

[0136] 110 Side sill frame 111 First side sill frame 112 Second side sill frame 113 Hollow portion 114 Joint 120 Reinforced frame 120U Unit Section 120U-1 1st Unit Section 120U-2 Second unit section 121a First flat section 121b Second plane part 121c Third plane part 121d 4th plane part 121e 5th plane part 121f 6th plane section 121g 7th plane section 121h 8th plane section 121i 9th plane section 121j 10th flat section 122 Inclined section 122a First slope part 122b Second slope part 122c Third slope part 122d Fourth slope part 122e 5th slope 122f 6th slope 122g 7th slope 122h 8th slope 122i 9th slope 122j 10th slope 122k 11th slope 122l 12th slope 122m 13th slope 122n 14th slope 122o 15th slope 122p 16th slope 122q 17th slope 122r 18th slope 122s 19th slope 122t 20th slope 130 Uneven part 131 Projecting part 132 Recess

Claims

1. A side sill frame including a hollow portion; and a reinforcing frame disposed inside the hollow portion in the longitudinal direction of the side sill frame; The reinforcing frame includes: The side sill frame has a unit section that is continuous in a longitudinal direction thereof and has a variable height, and an upper surface and a lower surface are spaced apart from the side sill frame, The unit interval is a first flat portion located parallel to a longitudinal direction of the side sill frame; a second planar portion located lower than the first planar portion; a first inclined portion that is connected from the first planar portion to the second planar portion and is disposed with a downward inclination; and a second inclined portion that is connected from the second planar portion to the first planar portion and is disposed with an upward inclination; The side sill frame is A first side sill frame to which one side of the reinforcing frame is joined; and a second side sill frame joined to the other side of the reinforcement frame and joined to the first side sill frame; The first planar portion and the second planar portion are The first side sill frame and the second side sill frame are disposed so that their joint portions face each other, The joint portion and the first flat portion are disposed on the upper side and spaced apart from each other while facing each other, A vehicle side sill, wherein the joint portion and the second flat portion, which are arranged on the lower side, are arranged facing each other and spaced apart from each other.

2. At least one of the first planar portion and the second planar portion is The vehicle side sill according to claim 1 , comprising an uneven portion.

3. 3. The vehicle side sill according to claim 2, wherein a length of the first planar portion and the second planar portion in a length direction of the side sill frame is any one value of 40 mm or more and 70 mm or less.

4. 3. The side sill for a vehicle according to claim 2, wherein an angle formed between an extension line of the first flat portion and the first inclined portion and an angle formed between an extension line of the second flat portion and the second inclined portion are any one of values ​​greater than or equal to 45° and less than or equal to 75°.

5. A side sill frame including a hollow portion; and a reinforcing frame disposed inside the hollow portion in the longitudinal direction of the side sill frame; The reinforcing frame includes: The side sill frame has a unit section that is continuous in a longitudinal direction thereof and has a variable height, and an upper surface and a lower surface are spaced apart from the side sill frame, The unit interval is a third planar portion located parallel to the longitudinal direction of the side sill frame; a third inclined portion connected to the third flat portion and inclined upward; and a fourth inclined portion connected to the third inclined portion and inclined downward; The side sill frame is A first side sill frame to which one side of the reinforcing frame is joined; and a second side sill frame joined to the other side of the reinforcement frame and joined to the first side sill frame; The third planar portion is The first side sill frame and the second side sill frame are disposed so that their joint portions face each other, A vehicle side sill, wherein the joint portion and the third flat portion, which are arranged on a lower side, are arranged facing each other and spaced apart from each other.

6. A side sill frame including a hollow portion; and a reinforcing frame disposed inside the hollow portion in the longitudinal direction of the side sill frame; The reinforcing frame includes: The side sill frame has a unit section that is continuous in a longitudinal direction thereof and has a variable height, and an upper surface and a lower surface are spaced apart from the side sill frame, The unit interval is a fourth planar portion located parallel to the longitudinal direction of the side sill frame; a fifth inclined portion connected to the fourth flat portion and inclined downward; and a sixth inclined portion connected to the fifth inclined portion and inclined upward; The side sill frame is A first side sill frame to which one side of the reinforcing frame is joined; and a second side sill frame joined to the other side of the reinforcement frame and joined to the first side sill frame; The fourth planar portion is The first side sill frame and the second side sill frame are disposed so that their joint portions face each other, A vehicle side sill, wherein the joint portion arranged on an upper side and the fourth flat portion are arranged facing each other and spaced apart from each other.

7. A side sill frame including a hollow portion; and a reinforcing frame disposed inside the hollow portion in the longitudinal direction of the side sill frame; The reinforcing frame includes: The side sill frame has a unit section that is continuous in a longitudinal direction thereof and has a variable height, and an upper surface and a lower surface are spaced apart from the side sill frame, The unit interval is A first unit section disposed on the upper side in the height direction; and a second unit section disposed below the first unit section; The first unit section is a seventh flat portion located parallel to the longitudinal direction of the side sill frame; a thirteenth inclined portion connected to the seventh flat portion and inclined upward; an eighth flat portion connected to the thirteenth inclined portion and located lower than the seventh flat portion; and a fourteenth inclined portion connected to the eighth flat portion and inclined downward; The second unit section is a ninth flat portion located parallel to the longitudinal direction of the side sill frame; a fifteenth inclined portion connected to the ninth flat portion and inclined downward; a tenth flat portion connected to the fifteenth inclined portion and located lower than the ninth flat portion; and a sixteenth inclined portion connected to the tenth flat portion and inclined upward; The side sill frame is A first side sill frame to which one side of the reinforcing frame is joined; and a second side sill frame joined to the other side of the reinforcement frame and joined to the first side sill frame; The eighth planar portion and the tenth planar portion are The first side sill frame and the second side sill frame are disposed so that their joint portions face each other, the joint portion and the eighth flat portion disposed on the upper side are disposed apart from each other while facing each other, A vehicle side sill, wherein the joint portion and the tenth planar portion, which are arranged on a lower side, are arranged facing each other and spaced apart from each other.

8. The vehicle side sill according to claim 7 , wherein the seventh planar portion and the ninth planar portion are disposed in contact with each other.

9. 9. The vehicle side sill according to claim 1, wherein at least one of the side sill frame and the reinforcing frame is made of a steel material.

10. The reinforcing frame includes:

9. The side sill for a vehicle according to any one of claims 1, 2, 5, 6, 7 and 8, which is made of a single steel plate.

11. 9. The vehicle side sill according to claim 1, wherein the reinforcing frame has a thickness of at least 1.8 mm and not more than 2.2 mm.

12. The reinforcing frame includes:

9. The side sill for a vehicle according to claim 1, wherein the side sill has a tensile strength of 1180 MPa or more and a yield strength of any one of 850 MPa or more and 1060 MPa or less.

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