Side sill for vehicle

Abstract

The present invention provides a side sill for a vehicle, the side sill comprising: an inner panel; an outer panel which is coupled to the inner panel in the width direction and forms a hollow part together with the inner panel; and a reinforcement frame which is arranged in the hollow part and in which a plurality of unit reinforcement bodies having shapes corresponding to each other are connected in the longitudinal direction.

Description

Side sill for vehicles

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

[0002] It is to be noted that the content described in this section merely provides background information for the present invention and does not constitute prior art.

[0003] In general, when a vehicle is hit from the side, the stress concentration phenomenon in the lower part of the vehicle body, that is, the side sill, causes severe deformation here, and as a result, the amount of interior air entering the side sill increases, so it can be seen that the degree of injury to the pelvic area of ​​the passenger's body is greatly affected.

[0004] Typically, side sills are very long, encompassing the entire passenger compartment. Furthermore, to enhance the side sill's crash-absorbing capacity, ultra-high-strength or thick materials are used for reinforcements and other components.

[0005] When applying reinforcing elements such as uneven sections to ensure high rigidity in these large parts, high forming loads are required to manufacture these large parts.

[0006] In the case of large parts manufacturers, they have facilities such as large presses that can apply high forming loads, but in some countries where small parts manufacturers or the industrial base is not developed, they are having difficulty forming the relevant parts because they cannot apply high forming loads.

[0007] (Patent Document 1) KR 20-1998-0043143 U

[0008] The present invention, in one aspect, seeks to provide a side seal that enables molding of a product even under a small molding load.

[0009] The present invention, in one aspect, seeks to provide a side seal in which the cost of mold manufacturing can be reduced by repeating a cross-section of the same pattern in the longitudinal direction.

[0010] As one aspect for achieving the above object, the present invention provides a vehicle side sill including: an inner panel; an outer panel that is joined to the inner panel in the width direction to form a hollow portion together with the inner panel; and a reinforcing frame that is arranged in the hollow portion and has a plurality of unit reinforcing bodies having corresponding shapes connected in the length direction.

[0011] The vehicle side sill of the present invention has the effect of enabling molding of a product even under a small molding load.

[0012] The above unit reinforcement body can be joined to the inner panel to form a closed cross-section.

[0013] The above unit reinforcement body can be manufactured as a single piece by forming a single steel plate.

[0014] The above unit reinforcement can be manufactured by forming a single steel plate having a tensile strength of 780 MPa or more.

[0015] The above unit reinforcement may include a protruding portion in the longitudinal cross-section.

[0016] The above-mentioned uneven portion may have protruding surfaces and indented surfaces alternately formed in the longitudinal direction, and an inclined surface may be formed between the protruding surfaces and the indented surfaces.

[0017] In the above reinforcing frame, at least one of the plurality of unit reinforcing members connected in the longitudinal direction may have a different steel grade or tensile strength.

[0018] The above reinforcing frame can be welded so that two unit reinforcing bodies connected in the longitudinal direction are in contact with each other at their longitudinal ends.

[0019] The above reinforcing frame has an overlapping area in which two unit reinforcing bodies connected in the longitudinal direction overlap each other in the thickness direction, and can be welded and joined in the overlapping area.

[0020] The unit reinforcing body includes a first unit reinforcing body having one side joined to the inner panel to form a first closed cross-section; and a second unit reinforcing body having one side joined to the first unit reinforcing body to form a second closed cross-section; and the reinforcing frame includes a first overlapping region in which two of the first unit reinforcing bodies connected in the longitudinal direction overlap in the thickness direction; and a second overlapping region in which two of the second unit reinforcing bodies connected in the longitudinal direction overlap in the thickness direction; and the first overlapping region and the second overlapping region can be arranged at positions corresponding to each other in the longitudinal direction.

[0021] In the portion where the first overlapping area and the second overlapping area overlap, the two first unit reinforcements of the first overlapping area and the two second unit reinforcements of the second overlapping area can be welded together in a four-layered state.

[0022] The unit reinforcing body includes a first unit reinforcing body having one side joined to the inner panel to form a first closed cross-section; and a second unit reinforcing body having one side joined to the first unit reinforcing body to form a second closed cross-section; and the reinforcing frame includes a first overlapping region in which two of the first unit reinforcing bodies connected in the longitudinal direction overlap in the thickness direction; and a second overlapping region in which two of the second unit reinforcing bodies connected in the longitudinal direction overlap in the thickness direction; and the first overlapping region and the second overlapping region can be arranged to be staggered in the longitudinal direction.

[0023] In the portion where the second unit reinforcement body overlaps the first overlapping area, two of the first unit reinforcement bodies and one of the second unit reinforcement bodies in the first overlapping area can be welded and joined in a three-layered state.

[0024] In the part where the second overlapping area overlaps the first unit reinforcement, the two second unit reinforcements and the first unit reinforcement of the second overlapping area can be welded together in a three-layered state.

[0025] The above unit reinforcement may include a first unit reinforcement having one side joined to the inner panel to form a first closed cross-section; and a second unit reinforcement having one side joined to the first unit reinforcement to form a second closed cross-section.

[0026] The first unit reinforcing body has a bending point that protrudes outward from the first closed cross-section, and the first unit reinforcing body can be formed at a position where the bending point is spaced apart from the first inner surface of the inner panel by a distance of 30 to 70% of the installation width of the first unit reinforcing body.

[0027] The first unit reinforcing body includes a first section extending in the first inner direction of the inner panel with the bending point as the boundary; and a second section extending in the second inner direction of the outer panel by being bent with the bending point as the boundary, and forming a bending angle with the first section within the first closed cross-section; and the first unit reinforcing body has the bending angle formed within the first closed cross-section, and the bending angle may have a range of 165 to 175 degrees.

[0028] The above inner panel is a vehicle side sill manufactured as a single piece by forming a single steel plate.

[0029] The above outer panel can be manufactured as a single piece by forming a single steel plate.

[0030] As one aspect for achieving the above object, the present invention provides a method for manufacturing a vehicle side sill, including a parts preparation step of preparing an inner panel, a plurality of unit reinforcing bodies, and an outer panel; a reinforcing frame manufacturing step of manufacturing a reinforcing frame by connecting a plurality of the unit reinforcing bodies in the longitudinal direction; a reinforcing frame joining step of joining the reinforcing frame to the inner panel; and an outer panel joining step of forming a hollow portion by joining the outer panel to the inner panel and arranging the reinforcing frame inside the hollow portion.

[0031] According to one embodiment of the present invention, there is an effect that molding of a product is possible even under a small molding load.

[0032] According to one embodiment of the present invention, there is an effect that the mold manufacturing cost can be reduced by repeating the cross-section of the same pattern in the longitudinal direction.

[0033] Fig. 1 is a perspective view of a vehicle side sill of a comparative example in contrast to the vehicle side sill of the present invention.

[0034] Fig. 2 is a perspective view of a reinforcing frame of a side sill for a vehicle of the comparative example of Fig. 1.

[0035] Figure 3 is a perspective view of a vehicle side sill according to the first embodiment of the present invention.

[0036] Fig. 4 is a perspective view of a reinforcing frame of a side sill for a vehicle of the first embodiment of Fig. 3.

[0037] Figure 5 is a perspective view showing an enlarged detail of part 'A' of Figure 4.

[0038] Figure 6 is a cross-sectional view taken along the line Ⅰ-Ⅰ' of Figure 3.

[0039] FIG. 7 is a drawing showing the position of the bending point of the vehicle side sill according to the first embodiment of FIG. 3.

[0040] Figure 8 is a perspective view of a vehicle side sill according to a second embodiment of the present invention.

[0041] Fig. 9 is a perspective view of a reinforcing frame of a side sill for a vehicle according to the second embodiment of Fig. 8.

[0042] Figure 10 is a perspective view showing an enlarged detail of part 'B' of Figure 9.

[0043] Fig. 11 is a cross-sectional view taken along the line Ⅱ-Ⅱ' of Fig. 9.

[0044] Fig. 12 is a perspective view of a reinforcing frame of a side sill for a vehicle included in the third embodiment of the present invention.

[0045] Figure 13 is a perspective view showing an enlarged detail of part 'C' of Figure 12.

[0046] Fig. 14 is a cross-sectional view taken along the line Ⅲ-Ⅲ' of Fig. 13.

[0047] Figure 15 is a perspective view showing an enlarged detail of the 'D' portion of Figure 12.

[0048] Fig. 16 is a cross-sectional view taken along the line Ⅳ-Ⅳ' of Fig. 15.

[0049] Figures 17a to 17c are drawings showing the results of deformation analysis of the vehicle side sill of the second embodiment of Figure 8.

[0050] Figures 18a to 18c are drawings showing the results of deformation analysis of the vehicle side sill of the comparative example of Figure 1.

[0051] Fig. 19 is a load-displacement diagram of the vehicle side sill of the comparative example of Fig. 1 and the vehicle side sill of the second embodiment of Fig. 8.

[0052] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. However, the embodiments of the present invention may be modified in various ways, 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 fully explain the present invention to those skilled in the art. The shapes and sizes of elements in the drawings may be exaggerated for clarity.

[0053] Referring to the drawings, the vehicle side sill of the present invention is illustrated in the left-right, up-down, and front-to-back directions, and although the terms left-to-right, up-to-down, and front-to-back directions are used in the detailed description of the invention, this is for the convenience of explanation, and it is to be noted that the technical features of the vehicle side sill of the present invention are not limited to these directions.

[0054] Below, the X-axis shown in the attached drawing 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.

[0055] Fig. 1 is a perspective view of a vehicle side sill of a comparative example in contrast to the vehicle side sill of the present invention. Fig. 2 is a perspective view of a reinforcing frame (30) of the vehicle side sill of the comparative example of Fig. 1.

[0056] In the case of the comparative example, the inner panel (10') and the outer panel (20') are the same as those of the first embodiment described later, and unlike the first embodiment described later, the vehicle side sill of the comparative example is different in that one reinforcing frame (30') is formed to extend along the entire length direction (Y).

[0057] When the same material, same thickness, and same cross-section shape are used, the forming load increases in proportion to the volume of the divided parts. As in the first embodiment described below, when the reinforcing frame (30) is manufactured by dividing it in the longitudinal direction (Y), the forming load can be reduced by the number of divisions.

[0058] For example, a reinforcing frame (30) can be divided into three parts in the longitudinal direction (Y) to manufacture a unit reinforcing body (30U). At this time, the forming load for forming each of the three-part unit reinforcing bodies (30U) can be reduced to approximately 1 / 3 compared to the forming load when the entire non-divided reinforcing frame (30') is formed as a single piece.

[0059] Hereinafter, components included in a vehicle side sill according to the first embodiment of the present invention will be specifically described with reference to FIGS. 3 to 6.

[0060] FIG. 3 is a perspective view of a vehicle side sill according to the first embodiment of the present invention, and FIG. 4 is a perspective view of a reinforcing frame (30) of the vehicle side sill according to the first embodiment of FIG. 3.

[0061] Fig. 5 is a perspective view showing an enlarged detail of part 'A' of Fig. 4, and Fig. 6 is a cross-sectional view in the XZ axis direction of Fig. 3.

[0062] A vehicle side sill according to one embodiment of the present invention may include an inner panel (10), an outer panel (20), and a reinforcing frame (30).

[0063] The inner panel (10) can be placed on the inner side of the side sill in the width direction (X) in the X-axis direction.

[0064] The outer panel (20) can be joined to the inner panel (10) in the width direction (X) to form a hollow portion (S) together with the inner panel (10). The outer panel (20) can be arranged on the outside of the side sill in the width direction (X) in the X-axis direction.

[0065] The inner panel (10) and the outer panel (20) can be welded together to form a welded portion (W). For example, the inner panel (10) and the outer panel (20) can be welded together by spot welding or the like.

[0066] The reinforcing frame (30) is placed in the hollow portion (S), and a plurality of unit reinforcing bodies (30U) having corresponding shapes can be connected in the longitudinal direction (Y).

[0067] The reinforcing frame (30) may have a shape in which a plurality of unit reinforcing bodies (30U) correspond to each other. For example, two adjacent unit reinforcing bodies (30U) that are connected may have their longitudinal (Y) ends welded to each other.

[0068] In this specification, the reinforcing frame (30) is illustrated and described as having three unit reinforcing bodies (30U) connected in the longitudinal direction (Y), but it is not necessarily limited to this, and it is also possible for two or more than three unit reinforcing bodies (30U) to be connected in the longitudinal direction (Y).

[0069] Since the unit reinforcement (30U) is shorter than the reinforcement frame (30), the unit reinforcement (30U) can be manufactured under a small forming load.

[0070] A plurality of unit reinforcements (30U) may have cross-sections corresponding to each other on the XZ-axis cross-section of the side sill, and a constant unit pattern may be repeated in the longitudinal direction (Y). For example, the unit reinforcements (30U) may have a constant unit pattern in which a protruding portion (P), which will be described later, is repeated in the longitudinal direction (Y).

[0071] For example, the unit reinforcement (30U) can be manufactured from steel. When steel is used to manufacture the unit reinforcement (30U), the impact energy absorption capacity is excellent, mechanical rigidity is improved, and material costs can be drastically reduced compared to when aluminum is used for the unit reinforcement (30U).

[0072] For example, a plurality of unit reinforcements (30U) may have corresponding shapes and have the same length in the longitudinal direction (Y). As another example, a plurality of unit reinforcements (30U) may have corresponding shapes and have different lengths in the longitudinal direction (Y).

[0073] A plurality of unit reinforcements (30U) can be welded together to form a weld (W). The weld (W) can be formed by spot welding, laser welding, arc welding, etc.

[0074] Of course, various joining methods such as welding joining or adhesive joining can be applied to the joining between members such as the inner panel (10), outer panel (20), and unit reinforcement (30U).

[0075] At least one of the inner panel (10), the outer panel (20), the first unit reinforcement (100), and the second unit reinforcement (200) may be composed of steel. For example, the inner panel (10), the outer panel (20), the first unit reinforcement (100), and the second unit reinforcement (200) may be composed of steel. Accordingly, the mechanical rigidity of the vehicle side sill may be improved.

[0076] The reinforcing frame (30) is manufactured by manufacturing a plurality of unit reinforcing bodies (30U) divided in the longitudinal direction (Y) and connecting the plurality of unit reinforcing bodies (30U) in the longitudinal direction (Y) to form the reinforcing frame (30), thereby producing the unit reinforcing bodies (30U) with a smaller forming load, thereby enabling the reinforcing frame (30) to be manufactured.

[0077] In addition, as the unit reinforcement (30U) of the side sill for vehicles can be formed even under a small forming load, the production of the product is possible even by small and medium-sized enterprises, which secures the diversity of sales channels for the product and has the effect of improving the salesability of the product.

[0078] In addition, it is possible to manufacture multiple identical unit reinforcements (30U) with one mold, and since the length of the unit reinforcements (30U) is short, there is an effect of reducing the manufacturing cost of the mold, etc.

[0079] The inner panel (10) can be manufactured as a single piece by forming a single steel plate. The inner panel (10) can be manufactured by forming a single steel plate along the entire length direction (Y) of the vehicle side sill.

[0080] The inner panel (10) is manufactured as a single piece by forming a single steel plate, so that the mechanical rigidity of the vehicle side sill can be improved as the inner panel (20) composed of a single steel plate moves as a single piece.

[0081] The outer panel (20) can be manufactured as a single piece by forming a single steel plate. The outer panel (20) can be manufactured by forming a single steel plate along the entire length direction (Y) of the vehicle side sill.

[0082] The outer panel (20) is manufactured as a single piece by forming a single steel plate, so that the mechanical rigidity of the vehicle side sill can be improved as the outer panel (20) composed of a single steel plate moves as a single piece.

[0083] For example, the inner panel (10) and the outer panel (20) can each be formed by folding a single steel plate into multiple stages.

[0084] The unit reinforcement (30U) can be joined to the inner panel (10) to form a closed cross-section.

[0085] The unit reinforcement (30U) is joined to the inner panel (10) to form a closed cross-section, thereby enhancing the crash absorption capacity of the vehicle side sill and improving its mechanical rigidity. In addition, while the vehicle side sill is composed of steel, the closed cross-section, which is an advantage of the aluminum extrusion method, can be easily formed.

[0086] For example, the closed cross-section formed by joining the first unit reinforcement (100) among the unit reinforcements (30U) to the inner panel (10) may be the first closed cross-section (M1) described later.

[0087] The unit reinforcement (30U) can be manufactured as a single piece by forming a single steel plate.

[0088] The unit reinforcement body (30U) is manufactured as a single piece by forming a single steel plate, so that the mechanical rigidity of the vehicle side sill can be improved as the unit reinforcement body (30U) composed of a single steel plate moves as a single piece.

[0089] For example, a unit reinforcement (30U) can be manufactured using a forming method such as foam forming or crash forming. By applying a low-cost forming method such as foam forming or crash forming, the production cost of the product can be reduced.

[0090] The unit reinforcement (30U) can be manufactured by forming a single steel plate having a tensile strength of 780 MPa or more.

[0091] Accordingly, when the reinforcing frame (30) included in the side sill for a vehicle is manufactured integrally along the entire length direction (Y) using high-strength materials, there is a problem in that a high forming load is required for the manufacture of the reinforcing frame (30), and it may become impossible for even small businesses such as small parts manufacturers to manufacture the product.

[0092] The present invention utilizes high-strength steel having a tensile strength of 780 MPa or more in the production of a reinforcing frame (30) for a vehicle side sill to improve mechanical rigidity, and enables the production of a unit reinforcing body (30U) with a low forming load, thereby enabling the production of products even by small and medium-sized enterprises, thereby securing a variety of sales channels for the product and thereby improving the saleability of the product.

[0093] More preferably, the unit reinforcement (30U) can be manufactured by forming a single steel plate having a tensile strength of 980 MPa or more.

[0094] The unit reinforcement (30U) may include a protruding portion (P) in the longitudinal direction (Y) cross-section. The unit reinforcement (30U) may have the protruding portion (P) repeated in the longitudinal direction (Y).

[0095] The unit reinforcement (30U) can improve rigidity without increasing the thickness of the steel material, etc. constituting the unit reinforcement (30U) by including a roughened portion (P).

[0096] The unit reinforcement (30U) may have a pattern of a certain shape, such as a protruding portion (P) to be described later, repeated in the longitudinal direction (Y). A plurality of unit reinforcements (30U) may have cross-sections that correspond to each other on the XZ-axis cross-section and may have a certain pattern repeated in the longitudinal direction (Y).

[0097] The uneven portion (P) has a protruding surface (P1) and an indented surface (P2) alternately formed in the longitudinal direction (Y), and an inclined surface (P3) can be formed between the protruding surface (P1) and the indented surface (P2).

[0098] The reinforcing frame (30) may have at least one unit reinforcing body (30U) connected in the longitudinal direction (Y) that may have a different steel grade or tensile strength.

[0099] For example, the unit reinforcement (30U) placed in the central region in the longitudinal direction (Y) may have a different steel grade from the unit reinforcement (30U) placed in the end regions on both sides in the longitudinal direction (Y).

[0100] For example, a unit reinforcement (30U) placed in the central region in the longitudinal direction (Y) can have a greater tensile strength than a unit reinforcement (30U) placed in the end regions on both sides in the longitudinal direction (Y).

[0101] The reinforcing frame (30) can be welded so that two adjacent unit reinforcing bodies (30U) are joined with their longitudinal (Y) ends facing each other. The two adjacent unit reinforcing bodies (30U) can have cross-sections with corresponding longitudinal (Y) end shapes. The unit reinforcing bodies (30U) can be welded together to form a welded portion (W). The welded portion (W) can be formed by laser welding, arc welding, or the like.

[0102] The unit reinforcement (30U) may include a first unit reinforcement (100) and a second unit reinforcement (200).

[0103] The first unit reinforcement body (100) can be joined on one side to the inner panel (10) to form a first closed cross-section (M1). Accordingly, the mechanical rigidity of the vehicle side sill can be improved.

[0104] The first unit reinforcement body (100) may include a first upper flange (110), a pair of first web members (130), and a pair of first lower flanges (150) on the XZ-axis cross-section of the side sill.

[0105] A first web member (130) may be connected to each of the ends on both sides in the height direction (Z) of the first upper flange (110). When the second lower flange (250) is joined to the first web member (130), the first upper flange (110) may be arranged at the boundary between the first closed cross-section (M1) and the second closed cross-section (M2).

[0106] For example, a first unit reinforcement body (100) and an inner panel (10) may be welded together to form a welded portion (W). The welded portion (W) may be formed by spot welding, etc.

[0107] The second unit reinforcing body (200) can be joined on one side to the first unit reinforcing body (100) to form a second closed cross-section (M2). Accordingly, the mechanical rigidity of the vehicle side sill can be improved.

[0108] The second unit reinforcement body (200) may include a second upper flange (210), a pair of second web members (230), and a pair of second lower flanges (250) on the XZ-axis cross-section of the side sill.

[0109] The second lower flange (250) of the second unit reinforcement (200) can be joined to the first web member (130) of the first unit reinforcement (100).

[0110] The second lower flange (250) may have a step formed between the second web members (230), and the Z-axis distance between a pair of second lower flanges (250) may be wider than the Z-axis distance between a pair of second web members (230).

[0111] For example, a second unit reinforcing member (200) of a reinforcing frame (30) and an outer panel (20) may be joined to form a welded portion (W). The welded portion (W) may be formed by spot welding or laser welding.

[0112] As another example, a bonding portion (V) may be formed when the second unit reinforcing body (200) of the reinforcing frame (30) and the outer panel (20) are joined. The bonding portion (V) may be formed using an adhesive.

[0113] As another example, the second unit reinforcement (200) of the reinforcing frame (30) and the outer panel (20) may not be joined.

[0114] For example, a first unit reinforcement body (100) and a second unit reinforcement body (200) may be welded together to form a weld (W). The weld (W) may be formed by spot welding or laser welding.

[0115] The protruding surface (P1) of the first unit reinforcement (100) may overlap the protruding surface (P1) of the second unit reinforcement (200), and the inward surface (P2) of the first unit reinforcement (100) may overlap the inward surface (P2) of the second unit reinforcement (200).

[0116] The protruding surfaces (P1) of the first unit reinforcement (100) and the second unit reinforcement (200) overlap each other, and the indented surfaces (P2) of the first unit reinforcement (100) and the second unit reinforcement (200) overlap each other, thereby improving the bonding strength of the first unit reinforcement (100) and the second unit reinforcement (200), and the bonding position of the first unit reinforcement (100) and the second unit reinforcement (200) can be naturally induced, thereby improving the workability of the worker.

[0117] FIG. 7 is a drawing showing the position (U) of the bending point (170) of the vehicle side sill according to the first embodiment of FIG. 3.

[0118] The first unit reinforcement body (100) may have a bending point (170) that protrudes outward from the first closed cross-section (M1).

[0119] The first unit reinforcement (100) can be formed at a position where the position (U) of the bending point (170) is spaced apart from the first inner surface (11) of the inner panel (10) by 30 to 70% of the installation width (T) of the first unit reinforcement (100).

[0120] By forming at a position spaced apart by a distance of 30 to 70% of the installation width (T) of the first unit reinforcement (100), bending is well induced at the bending point (170), normal compression can be achieved, and there is an effect of being able to exhibit sufficient load performance.

[0121] On the other hand, if the bending point (170) is less than 30% or more than 70% of the installation width (T) of the first unit reinforcement (100) on the first inner surface (11) of the inner panel (10), normal compression may not occur because bending induction is not performed well at the bending point (170) of the first unit reinforcement (100).

[0122] If normal compression failure does not occur in the first unit reinforcement body (100), a problem may arise where the first unit reinforcement body (100) cannot exhibit sufficient load performance due to deformation that causes it to tilt. In addition, this may become a major source of uncertainty in the ability of the vehicle side sill to exhibit stable collision energy absorption performance under various collision environments.

[0123] The first unit reinforcement (100) may include a first section (131) and a second section (133).

[0124] The first section (131) can be formed to extend in the direction of the first inner surface (11) of the inner panel (10) with the bending point (170) as the boundary.

[0125] The second section (133) is formed by extending in the direction of the second inner surface (21) of the outer panel (20) by bending with the bending point (170) as the boundary, and can form a bending angle (190) with the first section (131) inside the first closed cross-section (M1).

[0126] A bending point (170) may be provided at the boundary between the first section (131) and the second section (133).

[0127] The first unit reinforcement body (100) can be bent into a first section (131) and a second section (133) with the bending point (170) as the boundary.

[0128] The bending angle (190) is formed inside the first closed cross-section (M1) and may be configured to be less than 180 degrees.

[0129] The first unit reinforcing body (100) has a bending angle (190) formed inside the first closed cross-section (M1), and the bending angle (190) can have a range of 165 to 175 degrees. The angle (θ) formed by the extension line of the first section (131) and the extension line of the second section (133) can have a range of 5 to 15 degrees.

[0130] As the first section (131) and the second section (133) are bent based on the bending point (170), a bending angle (190) can be formed inside the first closed cross-section (M1).

[0131] The first unit reinforcement (100) has a bending angle (190) in the range of 165 to 175 degrees, so that the rigidity of the first unit reinforcement (100) can be sufficiently secured while stably inducing bending at the bending point (170).

[0132] When the bending angle (190) of the first unit reinforcement (100) is less than 165 degrees, bending can be easily induced at the bending point (170), but if bending is induced too easily at the bending point (170) of the first unit reinforcement (100), a problem may arise in that the load performance may be reduced as the first unit reinforcement (100) bends at the bending point (170) before it exerts the designed load performance.

[0133] If the first unit reinforcement (100) does not experience normal compression collapse and instead experiences tilting deformation, it may not be able to exhibit sufficient load performance. In addition, this may become a major source of uncertainty in the vehicle side sill's ability to exhibit stable collision energy absorption performance under various collision environments.

[0134] If the bending angle (190) exceeds 175 degrees, normal compression may not occur because bending induction is not performed well at the bending point (170).

[0135] A problem may arise where normal compression failure does not occur in the first unit reinforcement (100) and tilting deformation occurs, making it impossible to achieve the designed load performance.

[0136] Hereinafter, components included in a vehicle side sill according to the second and third embodiments of the present invention will be specifically described with reference to FIGS. 8 to 16.

[0137] Fig. 8 is a perspective view of a vehicle side sill according to a second embodiment of the present invention. Fig. 9 is a perspective view of a reinforcing frame of the vehicle side sill according to the second embodiment of Fig. 8.

[0138] Fig. 10 is a perspective view showing an enlarged detail of part 'B' of Fig. 9. Fig. 11 is a cross-sectional view taken along the line Ⅱ-Ⅱ' of Fig. 9.

[0139] Fig. 12 is a perspective view of a reinforcing frame of a side sill for a vehicle included in the third embodiment of the present invention. Fig. 13 is a perspective view showing an enlarged detail of part 'C' of Fig. 12. Fig. 14 is a cross-sectional view taken along line Ⅲ-Ⅲ' of Fig. 13.

[0140] Fig. 15 is a perspective view showing an enlarged detail of the 'D' portion of Fig. 12. Fig. 16 is a cross-sectional view taken along the line Ⅳ-Ⅳ' of Fig. 15.

[0141] According to the first embodiment of the present invention, two unit reinforcing bodies (30U) connected in the longitudinal direction of a vehicle side sill are welded together with their longitudinal ends facing each other.

[0142] On the other hand, the vehicle side sill according to the second embodiment and the third embodiment of the present invention is different only in that it is configured to apply the overlap welding method described later instead of the butt welding method of the first embodiment, and the remaining components may be the same as the configuration of the vehicle side sill of the first embodiment described above.

[0143] Therefore, to avoid duplication of content, a detailed description thereof will be omitted. However, it should be noted that various embodiments of the common components of the first embodiment described above can be applied to the second and third embodiments.

[0144] The reinforcing frame has an overlapping area in which two unit reinforcing bodies (30U) connected in the longitudinal direction overlap each other in the thickness direction, and can be welded and joined in the overlapping area.

[0145] The overlapping unit reinforcements (30U) can be manufactured with the cross-sectional dimensions partially adjusted to facilitate overlapping in the overlapping area. Accordingly, two unit reinforcements (30U) connected in the longitudinal direction can overlap each other in the thickness direction.

[0146] Two unit reinforcements (30U) connected in the longitudinal direction can form an overlapping area when one unit reinforcement (30U) is inserted into the other unit reinforcement (30U) in the longitudinal direction. In the overlapping area, the cross-section of one unit reinforcement (30U) inserted inward can be manufactured to have a smaller dimension than the cross-section of the other unit reinforcement (30U) positioned on the outside.

[0147] Accordingly, two adjacent unit reinforcements (30U) can overlap each other in the thickness direction in the overlapping area, and two adjacent unit reinforcements (30U) can be joined by an overlapping welding method in the overlapping area. The unit reinforcements (30U) can be welded to each other to form a welded portion (W). The welded portion (W) can be formed by spot welding or laser welding.

[0148] Referring to FIGS. 8 to 11, in a vehicle side sill according to the second embodiment of the present invention, a unit reinforcing body (30U) may include the first unit reinforcing body (100) and the second unit reinforcing body (200) described above. The reinforcing frame may include a first overlapping area (N1) and a second overlapping area (N2).

[0149] The first overlapping region (N1) may be formed by overlapping two first unit reinforcing bodies (100) that are connected in the longitudinal direction in the thickness direction. The second overlapping region (N2) may be formed by overlapping two second unit reinforcing bodies (200) that are connected in the longitudinal direction in the thickness direction.

[0150] The first overlapping area (N1) and the second overlapping area (N2) can be arranged at positions corresponding to each other in the longitudinal direction.

[0151] The first overlapping area (N1) and the second overlapping area (N2) may overlap each other at least partially.

[0152] In the portion where the first overlapping area (N1) and the second overlapping area (N2) overlap, the two first unit reinforcement bodies (100) of the first overlapping area (N1) and the two second unit reinforcement bodies (200) of the second overlapping area (N2) can be welded together in a four-layered state.

[0153] In a portion where the first overlapping area (N1) and the second overlapping area (N2) do not overlap, the first overlapping area (N1) can be welded in a state where two first unit reinforcements (100) connected in the longitudinal direction are overlapped in two layers.

[0154] In a portion where the first overlapping area (N1) and the second overlapping area (N2) do not overlap, the second overlapping area (N2) can be welded in a state where two second unit reinforcements (200) connected in the longitudinal direction are overlapped in two layers.

[0155] Referring to FIGS. 12 to 16, in a vehicle side sill according to the third embodiment of the present invention, a unit reinforcing body (30U) may include the first unit reinforcing body (100) and the second unit reinforcing body (200) described above. The reinforcing frame may include the first overlapping area (N1) and the second overlapping area (N2) described above. The first overlapping area (N1) and the second overlapping area (N2) may be arranged to be staggered in the longitudinal direction.

[0156] The second unit reinforcement (200) can be installed so as to overlap to cover at least a portion of the first overlapping area (N1).

[0157] At the part where the second unit reinforcement (200) overlaps with the first overlapping area (N1), two of the first unit reinforcements (100) and one of the second unit reinforcements (200) of the first overlapping area (N1) can be welded together in a three-layered state.

[0158] The second overlapping area (N2) may be installed to cover a portion of the first unit reinforcement body (100). In the portion where the second overlapping area (N2) overlaps the first unit reinforcement body (100), the two second unit reinforcement bodies (200) of the second overlapping area (N2) and the first unit reinforcement body (100) may be welded together in a three-layered state.

[0159] Hereinafter, with reference to FIGS. 17a to 18c, the deformation analysis results of the vehicle side sill of the second embodiment and the vehicle side sill of the comparative example will be described, and with reference to FIG. 19, the collision performance of the vehicle side sill of the second embodiment and the vehicle side sill of the comparative example will be compared and described.

[0160] Among the vehicle side sills according to the first to third embodiments of the present invention, the second embodiment and the comparative example were compared as representative examples.

[0161] The vehicle side sill of the second embodiment is formed by connecting a plurality of unit reinforcing bodies (30U) having shapes corresponding to each other in the longitudinal direction (Y) as reinforcing frames (30), and the vehicle side sill of the comparative example is different in that one reinforcing frame (30') is formed extending in the longitudinal direction (Y).

[0162] This is to examine whether there is a difference in the deformation analysis results and in the collision performance compared to the vehicle side sill of the comparative example when the vehicle side sill of the second embodiment is configured by connecting a plurality of unit reinforcing bodies (30U) in the longitudinal direction (Y) to form a reinforcing frame (30).

[0163] First, with reference to FIGS. 17a to 18c, the deformation analysis results of the vehicle side sill of the second embodiment and the vehicle side sill of the comparative example will be explained.

[0164] Figures 17a to 17c are drawings showing the results of deformation analysis of the vehicle side sill of the second embodiment.

[0165] Fig. 17a is a drawing showing the deformation analysis result of the initial period of the collision of the second embodiment, Fig. 17b is a drawing showing the deformation analysis result of the middle period of the collision of the second embodiment, and Fig. 17c is a drawing showing the deformation analysis result of the later period of the collision of the second embodiment.

[0166] Figures 18a to 18c are drawings showing the results of deformation analysis of a side sill for a vehicle of a comparative example.

[0167] Figure 18a is a drawing showing the deformation analysis result of the initial period of collision of a comparative example, Figure 18b is a drawing showing the deformation analysis result of the middle period of collision of a comparative example, and Figure 18c is a drawing showing the deformation analysis result of the later period of collision of a comparative example.

[0168] Referring to FIGS. 17a and 18c, it was confirmed that the second embodiment and the comparative example produced almost similar stable collision deformations in the early, middle, and late stages of the collision.

[0169] Next, with reference to Fig. 19, the collision performance of the side sill for the vehicle of the comparative example and the side sill for the vehicle of the second embodiment will be compared and explained.

[0170] Fig. 19 is a load-displacement diagram of the vehicle side sill of the comparative example of Fig. 1 and the vehicle side sill of the second embodiment of Fig. 8.

[0171] The load-displacement value of the vehicle side sill of the comparative example of Fig. 1 is represented as the first value (L1), and the load-displacement value of the vehicle side sill of the second embodiment of Fig. 8 is represented as the second value (L2).

[0172] Referring to the first value (L1) and the second value (L2), it can be seen that the vehicle side sill of the second embodiment of FIG. 8 and the vehicle side sill of the comparative example of FIG. 1 have almost similar displacements under the same load.

[0173] As a result of comparing the first value (L1) with the second value (L2), it can be seen that the second embodiment and the comparative example absorb the impact stably and almost similarly even after the collision.

[0174] Specifically, the internal energy of the side sill for the vehicle of the comparative example was 51.2 KJ, the weight of the side sill for the vehicle of the comparative example was 18.8 kg, the internal energy of the side sill for the vehicle of the second embodiment was 51.9 KJ, and the weight of the side sill for the vehicle of the second embodiment was 19.0 kg.

[0175] That is, the side sill for the vehicle of the comparative example has an internal energy ratio per 1 kg of 2.72 (KJ / kg), and the side sill for the vehicle of the second embodiment has an internal energy ratio per 1 kg of 2.73 (KJ / kg). It can be seen that the side sill for the vehicle of the second embodiment and the comparative example have almost similar internal energy ratios per 1 kg and almost similar energy absorption performances per unit weight.

[0176] Therefore, the vehicle side sill of the second embodiment of the present invention has the effect of stably securing collision performance while being capable of being formed even under a small forming load.

[0177] In addition, although not specifically presented in the drawings, it was confirmed that the vehicle side sill according to the first and third embodiments of the present invention also secured performance similar to that of the vehicle side sill according to the second embodiment of the present invention.

[0178] Next, the steps included in a method for manufacturing a vehicle side sill according to one embodiment of the present invention will be described in detail.

[0179] A method for manufacturing a side sill for a vehicle according to one embodiment of the present invention may include a parts preparation step, a reinforcing frame (30) manufacturing step, a reinforcing frame (30) bonding step, and an outer panel (20) bonding step.

[0180] The component preparation stage can prepare an inner panel (10), multiple unit reinforcements (30U), and an outer panel (20).

[0181] The reinforcing frame (30) manufacturing step can manufacture the reinforcing frame (30) by connecting a plurality of unit reinforcing bodies (30U) in the longitudinal direction (Y). The reinforcing frame (30) can be formed by connecting a plurality of unit reinforcing bodies (30U) having corresponding shapes in the longitudinal direction (Y). The plurality of unit reinforcing bodies (30U) can be welded to each other to form a welded portion (W).

[0182] The reinforcing frame (30) may have a shape in which a plurality of unit reinforcing bodies (30U) correspond to each other. For example, in the reinforcing frame (30), two adjacent unit reinforcing bodies (30U) may be welded together in a state in which their longitudinal (Y) ends abut each other. The two adjacent unit reinforcing bodies (30U) may have a cross-section in which their longitudinal (Y) ends correspond to each other. The unit reinforcing bodies (30U) may be welded together to form a welded portion (W). The welded portion (W) may be formed by laser welding, arc welding, or the like.

[0183] For example, a first unit reinforcement body (100) and a second unit reinforcement body (200) may be welded together to form a weld (W). The weld (W) may be formed by spot welding or laser welding.

[0184] The reinforcing frame (30) joining step can join the reinforcing frame (30) to the inner panel (10). The reinforcing frame (30) and the unit reinforcing body (30U) can be joined to the inner panel (10) to form a closed cross-section.

[0185] A welded portion (W) may be formed when the reinforcing frame (30) and the inner panel (10) are welded together. The welded portion (W) may be formed by spot welding, etc. Specifically, a welded portion (W) may be formed when the first unit reinforcing body (100) of the reinforcing frame (30) and the inner panel (10) are welded together.

[0186] The outer panel (20) bonding step may be performed by bonding the outer panel (20) to the inner panel (10) to form a hollow portion (S), and a reinforcing frame (30) may be placed inside the hollow portion (S).

[0187] The inner panel (10) and the outer panel (20) can be welded together to form a welded portion (W). For example, the inner panel (10) and the outer panel (20) can be welded together by spot welding or the like.

[0188] The outer panel (20) may or may not be joined to the second unit reinforcement body (200) of the reinforcing frame (30).

[0189] For example, a second unit reinforcing member (200) of a reinforcing frame (30) and an outer panel (20) may be joined to form a welded portion (W). The welded portion (W) may be formed by spot welding or laser welding.

[0190] As another example, a bonding portion (V) may be formed when the second unit reinforcing body (200) of the reinforcing frame (30) and the outer panel (20) are joined. The bonding portion (V) may be formed using an adhesive.

[0191] As another example, the second unit reinforcement (200) and the outer panel (20) may not be joined.

[0192] In addition, it goes without saying that various embodiments of the vehicle side sill having various embodiments described above can be applied to the method for manufacturing the vehicle side sill of the present invention.

[0193] Therefore, the configuration of the inner panel (10), outer panel (20), reinforcing frame (30), unit reinforcing body (30U), etc. of the vehicle side sill utilized in the method for manufacturing the vehicle side sill is the same as the configuration of the vehicle side sill as already described, and thus a detailed description thereof is omitted to avoid duplication.

[0194] The method for manufacturing a side sill for a vehicle is exemplified as a preferred manufacturing method so that a person having ordinary knowledge in the technical field of the present invention can easily carry out the present invention. In addition to the above-described order, the method may be modified and carried out according to a different order or other auxiliary processes may be added depending on specific field conditions.

[0195] 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 will be apparent to those skilled in the art that various modifications and variations are possible within a scope that does not depart from the technical spirit of the present invention described in the claims.

[0196] [Explanation of symbols]

[0197] 10, 10': Inner panel 11: First inner surface

[0198] 20, 20': Outer panel 21: Second inner panel

[0199] 30, 30': Reinforcement frame 30U: Unit reinforcement

[0200] 31': 1st reinforcing frame 32': 2nd reinforcing frame

[0201] 100: First unit reinforcement 110: First upper flange

[0202] 130: First web member 131: First section

[0203] 133: Section 2 150: Lower flange 1

[0204] 170: Bending point 190: Bending angle

[0205] 200: Second unit reinforcement 210: Second upper flange

[0206] 230: Second web member 250: Second lower flange

[0207] N1: First overlapping region N2: Second overlapping region

[0208] M1: First closed section M2: Second closed section

[0209] P: uneven surface P1: protruding surface

[0210] P2: Inner surface P3: Inclined surface

[0211] S: Hollow section T: Installation width of the first unit reinforcement

[0212] U: Location of bending point V: Adhesive

[0213] W: Welding X: Width direction

[0214] Y: length direction Z: height direction

Claims

1. Inner panel; An outer panel that is joined to the inner panel in the width direction to form a hollow portion together with the inner panel; and A side sill for a vehicle, comprising: a reinforcing frame in which a plurality of unit reinforcing bodies having corresponding shapes are arranged in the above hollow portion and are connected in the longitudinal direction; 2. In paragraph 1, A vehicle side sill in which the above unit reinforcement is joined to the inner panel to form a closed cross-section.

3. In paragraph 1, The above unit reinforcement is a vehicle side sill manufactured integrally by forming a single steel plate.

4. In paragraph 1, The above unit reinforcement is a vehicle side sill manufactured by forming a single steel plate having a tensile strength of 780 MPa or more.

5. In paragraph 1, The above unit reinforcement is a vehicle side sill including a protruding portion in the longitudinal cross-section.

6. In paragraph 5, the uneven portion is A side sill for a vehicle in which protruding surfaces and indented surfaces are alternately formed in the longitudinal direction, and an inclined surface is formed between the protruding surfaces and the indented surfaces.

7. In paragraph 1, the reinforcing frame, A side sill for a vehicle, wherein at least one of a plurality of longitudinally connected unit reinforcing members has a different steel grade or tensile strength.

8. In paragraph 1, the reinforcing frame, A vehicle side sill in which two longitudinally connected unit reinforcing bodies are welded together with their longitudinal ends facing each other.

9. In paragraph 1, the reinforcing frame, A vehicle side sill in which two unit reinforcing bodies connected in the longitudinal direction have an overlapping area in which they overlap each other in the thickness direction and are welded together in the overlapping area.

10. In the 9th paragraph, the unit reinforcement body is A first unit reinforcing body having one side joined to the inner panel to form a first closed cross-section; and A second unit reinforcing body having one side joined to the first unit reinforcing body to form a second closed cross-section; The above reinforcing frame is, A first overlapping region in which two first unit reinforcing bodies connected in the longitudinal direction overlap in the thickness direction; and A second overlapping region in which two second unit reinforcing bodies connected in the longitudinal direction overlap in the thickness direction; A vehicle side sill in which the first overlapping area and the second overlapping area are positioned corresponding to each other in the longitudinal direction.

11. In paragraph 10, In the part where the first overlapping area and the second overlapping area overlap, A side sill for a vehicle in which two first unit reinforcing bodies of the first overlapping area and two second unit reinforcing bodies of the second overlapping area are welded together in a four-layered state.

12. In the 9th paragraph, the unit reinforcement body is A first unit reinforcing body having one side joined to the inner panel to form a first closed cross-section; and A second unit reinforcing body having one side joined to the first unit reinforcing body to form a second closed cross-section; The above reinforcing frame is, A first overlapping region in which two first unit reinforcing bodies connected in the longitudinal direction overlap in the thickness direction; and A second overlapping region in which two second unit reinforcing bodies connected in the longitudinal direction overlap in the thickness direction; A vehicle side sill in which the first overlapping area and the second overlapping area are arranged to be staggered in the longitudinal direction.

13. In paragraph 12, In the portion where the second unit reinforcement overlaps the first overlapping area, A vehicle side sill in which two of the first unit reinforcements and one of the second unit reinforcements in the first overlapping area are welded together in a three-layered state.

14. In paragraph 12, In the part where the second overlapping area overlaps the first unit reinforcement, A vehicle side sill in which two of the second unit reinforcements and the first unit reinforcement of the second overlapping area are welded together in a three-layered state.

15. In the first paragraph, the unit reinforcement body is A first unit reinforcing body having one side joined to the inner panel to form a first closed cross-section; and A second unit reinforcing body having one side joined to the first unit reinforcing body to form a second closed cross-section; The above first unit reinforcement body is, A side sill for a vehicle having a bending point protruding outward from the first closed cross-section.

16. In the 15th paragraph, the first unit reinforcement body is A vehicle side sill in which the position of the above bending point is formed at a position spaced apart from the first inner surface of the inner panel by 30 to 70% of the installation width of the first unit reinforcement.

17. In the 15th paragraph, the first unit reinforcement body is A first section formed to extend in the first inner direction of the inner panel with the bending point as the boundary; and A second section is formed by bending with the bending point as the boundary and extending in the second inner direction of the outer panel, and forms a bending angle with the first section inside the first closed cross-section; The above first unit reinforcement body is, A vehicle side sill in which the above bending angle is formed inside the first closed cross-section, and the bending angle has a range of 165 to 175 degrees.

18. In paragraph 1, The above inner panel is a vehicle side sill manufactured as a single piece by forming a single steel plate.

19. In paragraph 1, The above outer panel is a vehicle side sill manufactured as a single piece by forming a single steel plate.

20. Parts preparation stage for preparing inner panels, multiple unit reinforcements, and outer panels; A reinforcing frame manufacturing step of manufacturing a reinforcing frame by connecting a plurality of the above unit reinforcing bodies in the longitudinal direction; A reinforcing frame joining step of joining the reinforcing frame to the inner panel; and A method for manufacturing a side sill for a vehicle, comprising: an outer panel bonding step of forming a hollow portion by bonding the outer panel to the inner panel, and arranging the reinforcing frame inside the hollow portion.

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