Vehicle side sills

Abstract

The present invention relates to a vehicle side sill, and includes a side sill frame including a hollow section, a connecting frame including a flange arranged in the longitudinal direction of the side sill frame in the hollow section and joined to the side sill frame, and a reinforcing frame arranged in the longitudinal direction of the side sill frame in the hollow section, joined to the connecting frame, and having unit sections with varying heights.

Description

TECHNICAL FIELD

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

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

[0003] The side sill for a vehicle serves to protect passengers by absorbing collision energy during a side collision.

[0004] Side sills applied to eco-friendly vehicles such as electric vehicles serve to protect not only passengers but also the battery located on the floor surface. Since the battery has a relatively large volume compared to other components of the vehicle, the side space of the vehicle equipped with the battery is relatively narrow compared to a vehicle equipped with an internal combustion engine.

[0005] Accordingly, the side sill applied to eco-friendly vehicles needs to be able to absorb maximum collision energy in a narrow space, and should have a minimum weight in order to improve the energy efficiency of the eco-friendly vehicle.

[0006] For this reason, aluminum extruded materials have been applied to the side sills of eco-friendly vehicles, but there is an actual situation where improvement of collision energy absorption capacity and achievement of weight reduction are still required. PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0007] PATENT DOCUMENT 1 KR 20-1998-0043143 U(1998.09.25) SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] This invention aims to solve the above problems, with the primary objectives being to improve the collision energy absorption efficiency and reduce the weight of the side sill.

[0009] The present invention aims to increase the rigidity of the side sill, reduce manufacturing costs such as mold costs, and improve assembly compared to existing designs. [Means for solving the problem]

[0010] To achieve the above objective, the present invention provides a vehicle side sill formed as follows.

[0011] A vehicle side sill according to one embodiment of the present invention includes a side sill frame including a hollow portion, a connecting frame including a flange arranged in the longitudinal direction of the side sill frame in the hollow portion and joined to the side sill frame, and a reinforcing frame arranged in the longitudinal direction of the side sill frame in the hollow portion, joined to the connecting frame, and having unit sections in which the height changes.

[0012] Furthermore, the connecting frame may include a connecting portion that extends across the hollow portion and contacts the reinforcing frame in at least a portion of its area.

[0013] Furthermore, the above-mentioned unit section may include a planar section that is located parallel to the longitudinal direction of the side sill frame and includes a first planar section and a second planar section located at a lower position than the first planar section, and an inclined section that is inclined following the planar section. [Effects of the Invention]

[0014] With the above configuration, the present invention can achieve improved collision energy absorption efficiency and weight reduction of the side sill.

[0015] Furthermore, it is possible to increase the rigidity of the side sill, reduce manufacturing costs such as mold costs, and improve ease of assembly. [Brief explanation of the drawing]

[0016] [Figure 1] It is a perspective view of a side sill according to an embodiment of the present invention. [Figure 2] It is still another perspective view of a side sill according to an embodiment of the present invention. [Figure 3] It is a perspective view of a connecting frame according to an embodiment of the present invention. [Figure 4] It is a perspective view of a reinforcement frame according to an embodiment of the present invention. [Figure 5] It is a perspective view of a reinforcement structure included in a side sill according to the first embodiment of the present invention. [Figure 6] It is an exploded view of the reinforcement structure included in the side sill according to the first embodiment of the present invention. [Figure 7] It is a cross-sectional view of the side sill according to the first embodiment of the present invention, taken along line A-A' in Fig. 5. [Figure 8] It is a cross-sectional view of the side sill according to the first embodiment of the present invention, taken along line B-B' in Fig. 5. [Figure 9] It is an exploded view of a reinforcement structure included in a side sill according to the second embodiment of the present invention. [Figure 10] It is an exploded view of a reinforcement structure included in a side sill according to the third embodiment of the present invention. [Figure 11] It is an exploded view of a reinforcement structure included in a side sill according to the fourth embodiment of the present invention. [Figure 12] It is a perspective view of a reinforcement structure included in a side sill according to an embodiment of the existing invention. [Figure 13] These are drawings for an experiment in which a side collision is applied to a part of a vehicle body structure including the reinforcement structure of the invention of Fig. 12, wherein (a) is a schematic cross-sectional view before impact is applied, and (b) is a schematic cross-sectional view after impact is applied. [Figure 14] These are drawings for an experiment in which a side collision is applied to a part of a vehicle body structure including the reinforcement structure of the first embodiment of the present invention as shown in Fig. 5, wherein (a) is a schematic cross-sectional view before impact is applied, and (b) is a schematic cross-sectional view after impact is applied. [Mode for Carrying Out the Invention]

[0017] Specific embodiments of the present invention will be described below with reference to the attached drawings. However, the concept of the present invention is not limited to the embodiments presented, and those skilled in the art who understand the concept of the present invention can easily propose other regressive inventions or other embodiments that fall within the scope of the present invention by adding, changing, or deleting other components within the same scope of the concept, and these can also be said to fall within the scope of the present invention.

[0018] In the attached drawings below, the X-axis represents the width direction of the side sill, the Y-axis represents the length direction of the side sill, and the Z-axis represents the height direction of the side sill. Furthermore, only a portion of the configuration extending in the length direction of the side sill may be shown.

[0019] Figures 1 and 2 show perspective views of a side sill according to one embodiment of the present invention, cut in the width direction. Figure 1 is a perspective view taken from the outside to the inside of a vehicle, based on the case where the side sill according to one embodiment of the present invention is installed on a vehicle, and Figure 2 is a perspective view taken from the inside to the outside.

[0020] A side sill according to one embodiment of the present invention includes a side sill frame 300, a connecting frame 100, and a reinforcing frame 200.

[0021] The side sill frame 300 can have a hollow section S inside and a shape that is elongated in the longitudinal direction.

[0022] As an example, it may include a first side sill frame 310 located inside the vehicle, and a second side sill frame 320 connected to the first side sill frame 310 and provided on the outside of the vehicle.

[0023] The side sill frame 300 may be formed from a single member, but for convenience of assembly and manufacturing, it may be provided with a first side sill frame 310 and a second side sill frame 320, and the first side sill frame 310 and the second side sill frame 320 may be joined together integrally by forming a joint portion 330 to which they are connected. The joint portion 330 may be provided with a first joint portion 331 and a second joint portion 332 at different positions in the height direction.

[0024] A side sill according to one embodiment of the present invention may further include an outer frame 400 coupled to a second side sill frame 320 on the outside of the vehicle. The outer frame 400 may be the exterior of the vehicle, or it may be another frame structure provided on the outside of the second side sill frame 320 rather than being an exterior.

[0025] The connecting frame 100 is positioned in the hollow section S along the length of the side sill frame 300 and is joined to the side sill frame 300.

[0026] The connecting frame 100 is connected to the side sill frame 300 and the reinforcement frame 200 described later, and this provides the effect of easier assembly compared to when the reinforcement frame 200 is directly connected to the side sill frame 300.

[0027] For example, if the reinforcing frame 200 is joined to the connecting frame 100 before the connecting frame 100 and the side sill frame 300 are joined, there may be advantages such as a shape that makes joining by welding etc. easier and angles that make joining work easier, compared to directly joining the reinforcing frame 200 to the side sill frame 300.

[0028] Furthermore, since the reinforced frame 200 and the side sill frame 300 are connected via the connecting frame 100, they are not joined by direct welding or the like, and the gap G (see Figures 7 and 8) between the reinforced frame 200 and the side sill frame 300 can be minimized, thereby allowing side impacts to be transmitted to and absorbed more effectively by the reinforced frame 200.

[0029] The reinforced frame 200 is positioned in the length direction of the side sill frame 300 within the hollow section S, is joined to the connecting frame 100, and has a unit section u in which the height changes.

[0030] The reinforced frame 200 is located in the hollow section S of the side sill frame 300, thereby increasing its ability to absorb impact forces from side collisions of the vehicle and protecting batteries and other components located inside the side sill in electric vehicles.

[0031] By positioning the connecting frame 100 and the reinforcing frame 200 so as to be separated from the upper and lower surfaces of the side sill frame 300, the connecting frame 100 and the reinforcing frame 200 can be positioned in the central region in the Z-axis direction so that they can achieve maximum deformation load when an impact is applied in the X-axis direction, such as in a side collision. This has the effect of improving collision energy absorption efficiency while maximizing vehicle weight reduction.

[0032] As an example, at least one of the side sill frame 300, the reinforcing frame 200, and the connecting frame 100 can be made of steel.

[0033] This allows for improved mechanical strength of the vehicle side sill. Furthermore, it allows for even greater collision energy absorption capacity compared to a vehicle side sill made of aluminum (not shown) of the same weight. Therefore, it is possible to realize a vehicle side sill with improved collision energy absorption capacity compared to an aluminum vehicle side sill, while preventing an increase in the overall load of the vehicle.

[0034] As an example, the reinforced frame 200 or the connecting frame 100 may be made of a single steel plate. It can be formed by bending a single steel plate. This allows for further improvement of the mechanical strength of the reinforced frame 200 or the connecting frame 100, and contributes to a reduction in manufacturing costs.

[0035] In one embodiment of the present invention, the reinforced frame 200 may have a tensile strength of 1180 MPa or more, while also having a yield strength of any one value between 850 MPa and 1060 MPa.

[0036] As described above, when a vehicle side sill is made of steel, its collision energy absorption capacity can be at least the same as, or even exceed, that of a vehicle side sill made of aluminum of the same weight.

[0037] Therefore, compared to when the side sills are made of aluminum, it is possible to reduce the weight of the side sills while improving the collision energy absorption efficiency to the same or even greater extent.

[0038] According to the vehicle side sill of the present invention as described above, 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, thereby improving its shock absorption capacity. Therefore, the transmission of shock to the space where the vehicle battery is located (not shown) and the space where passengers are located can be minimized.

[0039] The connecting frame will be explained below with reference to Figure 3, and the reinforced frame with reference to Figure 4.

[0040] Figure 3 is a perspective view showing a part of a connecting frame according to one embodiment of the present invention. The connecting frame has a long shape in the longitudinal direction, and the same shape can be repeatedly formed in the longitudinal direction.

[0041] As an example, the connecting frame 100 includes flanges 102 and 103 that are joined to the inner surface of the side sill frame 300, and a connecting portion 101 that is aligned in the width direction of the side sill and contacts the reinforcing frame 200 in at least a portion of the area.

[0042] The connecting frame 100 may have flanges 102 and 103 so as to be surface-jointed with the side sill frame 300. Furthermore, the rigidity against side impacts can be further increased by connecting portions 101 that extend across the hollow portion S of the side sill. As an example, the connecting portions 101 may be formed side by side in the width direction. Connecting portions 101 formed side by side in the width direction can be shorter in length and lighter in weight compared to cases where they are not side by side.

[0043] As an example, the flanges 102 and 103 of the connecting frame 100 may include a first flange 102 joined to the first side sill frame 310 and a second flange 103 joined to the second side sill frame 320. The side sill frame 300 and the connecting frame 100 may be joined on both sides, making the connection even stronger.

[0044] For example, the first flange 102 and the second flange 103 extend from the connecting portion 101, but the first flange 102 and the second flange 103 can extend in different directions from each other in the height direction.

[0045] The first flange 102 and the second flange 103 can be formed extending from the connecting portion 101, or they may be formed integrally. When the first flange 102 extends in a direction that increases in height, the second flange 103 can extend in a direction that decreases in height. Conversely, when the first flange 102 extends in a direction that decreases in height, the second flange 103 can extend in a direction that increases in height. The first flange 102 and the second flange 103 extend in different directions from each other, providing the effect of maintaining a joined state with the side sill frame 300 even when the side sill frame 300 is deformed, such as twisting, due to external impacts. However, the first flange 102 and the second flange 103 may extend in the same direction, and are not limited to extending in different directions as described above.

[0046] As an example, the first flange 102 and the second flange 103 may be formed from the connecting portion 101 and a single steel plate, and may be formed by bending.

[0047] The connecting frame 100 can be formed from a single steel plate. The connecting portion 101, the first flange 102, and the second flange 103 can be formed integrally, which can be done by bending the steel plate. Since the connecting frame 100 can be formed by bending only the connecting portion 101 and the flanges, it can offer the advantage of cost reduction compared to processing using press dies or the like.

[0048] As an example, a first through-hole 104 may be formed in the connecting portion 101.

[0049] The first through-hole 104, which is a through-hole formed in the connecting portion 101, is aligned with the through-hole of the reinforced frame 200 (described later) to facilitate positional alignment during connection. The position-regulating pin of the assembly jig can pass through while the positions between the connecting frame 100 and the reinforced frame 200 are aligned. In addition, it can also be used to remove air pockets and to facilitate the flow of the electrodeposition solution during electrodeposition painting of the vehicle body.

[0050] Figure 4 is a perspective view showing a part of a reinforced frame according to one embodiment of the present invention.

[0051] The reinforced frame 200 has a long shape in the longitudinal direction, and unit sections u of the same shape can be repeatedly formed in the longitudinal direction. This is to simultaneously achieve improved collision energy absorption efficiency in side collisions and weight reduction.

[0052] As an example, the reinforced frame 200 has repeating unit sections u, and each unit section u includes flat sections 101 and 103 and inclined sections 102 and 104 connected to the flat sections 101 and 103.

[0053] The planar sections 101 and 103 may include a first planar section 201 and a second planar section 203. The first planar section 201 may be located parallel to the longitudinal direction of the side sill frame 300, and the second planar section 203 may be located at a lower position than the first planar section 201.

[0054] The inclined portions 102 and 104 are arranged at an inclination following the planar portions 101 and 103, and may include a first inclined portion 202 and a second inclined portion 204. The first inclined portion 202 is arranged at an inclination downward following the first planar portion 201, and the second inclined portion 204 is arranged at an inclination upward following the second planar portion 203.

[0055] The shape can be continuously repeated vertically in the longitudinal direction, with the first planar section 201, the first inclined section 202, the second planar section 203, and the second inclined section 204 repeating in the unit section u.

[0056] The processing of a unit section u can be performed solely by bending, which offers the advantage of reducing costs compared to processing using press dies or the like.

[0057] For example, the lengths of the first planar portion 201 and the second planar portion 203 in the longitudinal direction may be the same, but are not limited to this, and may be formed in parallel.

[0058] The first inclined portion 202 and the second inclined portion 204 may be formed symmetrically with respect to the first planar portion 201 or the second planar portion 203, but they may not be symmetrical if the inclination angle θ1 formed by the extension of the first planar portion 201 and the first inclined portion 202 is different from the inclination angle θ2 formed by the second inclined portion 204.

[0059] For example, the inclination angle θ, which is the angle formed by the extension of the first planar portion 201 and the inclined portions 101 and 103, and the angle formed by the extension of the second planar portion 203 and the inclined portions 101 and 103, may be between 40° and 80°.

[0060] When more energy absorption is required, the inclination angle θ can be close to 80°, and when weight is minimized, it can be close to 40°. If the inclination angle θ exceeds 80°, the weight becomes too large, and if the inclination angle θ is less than 40°, the desired amount of energy absorption may not be achieved. In this invention, it is generally believed that using an angle of around 60° allows for an appropriate balance between weight and energy absorption, but as described above, the angle can be adjusted according to the required degree of energy absorption and weight reduction.

[0061] For example, a second through-hole 205 may be formed in the first flat portion 201, and a third through-hole 206 may be formed in the second flat portion 203.

[0062] Furthermore, some of the multiple first through holes 104 can be located in the same longitudinal and width directions as the second through holes 205 formed in the first flat portion 201, and other parts of the multiple first through holes 104 can be located in the same longitudinal and width directions as the third through holes 206 formed in the second flat portion 203.

[0063] The second through-hole 205 or the third through-hole 206 can be aligned with the first through-hole 104, and their position can be easily determined by a method such as through which a position-regulating pin for the assembly jig of the reinforcing frame 200 and the connecting frame 100 passes. Furthermore, if there are multiple reinforcing frames 200, the position determination between the reinforcing frames 200 can also be easily determined. In addition, they can be used to remove air pockets and to facilitate the flow of the electrodeposition solution during electrodeposition painting of the vehicle body.

[0064] When joining the reinforced frame 200 and the connecting frame 100 by welding or other means, the joining can be done via spot welding, laser welding, or other welding methods in areas where through holes have not been formed. At this time, the locations where structurally necessary joints must be formed by welding or other means through the second through hole 205 and the third through hole 206 can be easily identified.

[0065] In the following specific embodiments, multiple reinforcing frames 200 or multiple connecting frames 100 may be included. In the following description, the structure of the reinforcing frames 200 and the connecting frames 100 will be defined and described as a reinforcing structure.

[0066] Figure 5 shows a perspective view of the reinforcement structure of the reinforced frame and connecting frame, excluding the side sill frame, in a side sill according to the first embodiment of the present invention, and Figure 6 shows an exploded view of the reinforcement structure of the reinforced frame and connecting frame in Figure 5.

[0067] As an example, a plurality of the above-mentioned reinforcing frames 200 may be provided, and the second planar portion 213 of the first reinforcing frame 210, which is one of the plurality of reinforcing frames 200, may be arranged to be in contact with the first planar portion 221 of the second reinforcing frame 220, which is one of the plurality of reinforcing frames 200 that is not the first reinforcing frame 210. Furthermore, the length of the unit section u of the first reinforcing frame 210 and the second reinforcing frame 220 may be formed to be the same.

[0068] Furthermore, multiple connecting frames 100 are provided, and one of the multiple connecting frames 100, which is the first connecting frame 110, is in contact with the first planar portion 211, and a second connecting frame 120, which is one of the multiple reinforcing frames 200 that is not the first connecting frame 110, is in contact with the second planar portion 223.

[0069] The side sill according to the first embodiment may include a side sill frame 300, two reinforcing frames 200 and two connecting frames 100 in the reinforcing structure 10.

[0070] The second planar portion 213 of the first reinforcement frame 210, which is one of the two reinforcement frames 200, and the first planar portion 211 of the second reinforcement frame 220, which is the other reinforcement frame 200 (not the first reinforcement frame 210), can be arranged to be in contact with each other. The length of the unit section u of the first reinforcement frame 210 and the second reinforcement frame 220 can be formed to be the same.

[0071] The shapes of the two reinforcing frames 200 can be arranged so as to be symmetrical with respect to the second planar portion 213 of the first reinforcing frame 210 and the first planar portion 221 of the second reinforcing frame 220, which are the surfaces in contact with each other.

[0072] Furthermore, it includes a first connecting frame 110, which is one of the two connecting frames 100, and a second connecting frame 120, which is the other connecting frame 100. The first connecting frame 110 can be fixed in contact with the first reinforcing frame 210, and the second connecting frame 120 can be fixed in contact with the second reinforcing frame 220. Also, similar to the reinforcing frame 200, the first connecting frame 110 and the second connecting frame 120 can be formed symmetrically with respect to the second planar portion 213 of the first reinforcing frame 210 and the first planar portion 221 of the second reinforcing frame 220, which are the surfaces in contact with the two reinforcing frames 200.

[0073] For a detailed explanation of the side sill according to the first embodiment, refer to Figures 7 and 8. Figure 7 shows the A-A' section shown in Figure 5, and Figure 8 shows the B-B' section shown in Figure 5, but with the side sill frame and outer frame further included.

[0074] The first through-hole 104 of the first connecting frame 110 can be designated as the 1-1 through-hole 114, and the first through-hole 104 of the second connecting frame 120 can be designated as the 1-2 through-hole 124. Furthermore, the second through-hole 205 of the first reinforcing frame 210 can be designated as the 2-1 through-hole 215, the second through-hole 205 of the second reinforcing frame 220 can be designated as the 2-2 through-hole 225, the third through-hole 206 of the first reinforcing frame 210 can be designated as the 3-1 through-hole 216, and the third through-hole 206 of the second reinforcing frame 220 can be designated as the 3-2 through-hole 226.

[0075] Referring to Figure 7, a cross-section is shown in which the 1-1 through-hole 114 of the first connecting frame 110, the 2-1 through-hole 214 of the first reinforcing frame 210, the 1-2 through-hole 124 of the second connecting frame 120, and the 3-2 through-hole 226 of the second reinforcing frame 220 are aligned.

[0076] The outer surface 112a of the first flange 112 of the first connecting frame 110 is joined to the inner surface 311 of the hollow section S of the first side sill frame 310. The outer surface 123a of the second flange 123 of the first connecting frame 110 can be joined to the inner surface 321 of the hollow section S of the second side sill frame 320. The outer surface 123a of the second flange 123 of the second connecting frame 120 can be joined to the inner surface 311 of the hollow section S of the first side sill frame 310, and the outer surface 122a of the first flange 122 of the second connecting frame 120 can be joined to the inside of the hollow section S of the second side sill frame 320.

[0077] The side sill frame 300 and the connecting frame 100 can be joined using structural adhesive, but they can also be joined by welding, and there are no restrictions on other joining methods.

[0078] The upper surface 211a of the first planar portion 211 of the first reinforced frame 210 can be positioned in contact with the lower surface 111b of the connecting portion 111 of the first connecting frame 110, and the lower surface 223b of the second planar portion 223 of the second reinforced frame 220 can be positioned in contact with the upper surface 121a of the connecting portion 121 of the second connecting frame 120. A space is formed between the upper surface 111a of the connecting portion 111 of the first connecting frame 110 and the side sill frame 300, and between the lower surface 121b of the connecting portion 121 of the second connecting frame 120 and the side sill frame 300, providing the effect that the connecting frame 100 and the reinforced frame 200 can achieve maximum deformation load when an impact is applied in the X-axis direction, such as in a side collision.

[0079] The connection between the connecting frame 100 and the reinforcing frame 200 can be made by welding methods such as spot welding, laser welding, or arc welding, and structural bonding is also possible.

[0080] As described above, the first connecting frame 110 and the first side sill frame 310 or the second connecting frame 120 and the second side sill frame 320 are formed at a distance from each other. However, because the thickness of the connecting frame 100 is not large and the shape is simple, the gap G can be minimized, making assembly structurally easy and allowing for easy joining by welding, while also providing the effect of efficiently transmitting energy from side collisions.

[0081] Referring to Figure 8, a cross-section is shown in which the 1-1 through hole 114, the 3-1 through hole 216, the 2-2 through hole 225, and the 1-2 through hole 124 are aligned.

[0082] Looking at the B-B' section, it is the same that the outer surface 112b of the first flange 112 of the first connecting frame 110 can be joined to the inner surface 311 of the hollow portion S of the first side sill frame 310, the outer surface 113b of the second flange 113 of the first support frame 110 can be joined to the inner surface 321 of the hollow portion S of the second side sill frame 320, the outer surface 123b of the second flange 123 of the second connecting frame 120 can be joined to the inner surface 311a of the hollow portion S of the first side sill frame 310, and the outer surface 122b of the first flange 122 of the second connecting frame 120 can be joined to the inner surface 321 of the hollow portion S of the second side sill frame 320.

[0083] However, the first reinforcing frame 210 and the second reinforcing frame 220 may be formed with surfaces that abut each other, and may be formed symmetrically in the height direction with respect to these surfaces. The lower surface 213b of the second planar portion 213 of the first reinforcing frame 210 and the upper surface 221a of the first planar portion 221 of the second reinforcing frame 220 are in contact, and these surfaces can be joined by various joining methods such as spot welding.

[0084] Furthermore, the size of the open space between the upper surface 213a of the second planar portion 213 of the first reinforcement frame 210 and the first connecting frame 110, and between the lower surface 221b of the first planar portion 221 of the second reinforcement frame 220 and the second connecting frame 120 may vary depending on the inclination angle θ.

[0085] Furthermore, it can be seen that, as with the cross-section A-A', a gap G is formed between the first reinforcement frame 210 and the second reinforcement frame 220 and the side sill frame 300 in the cross-section B-B'.

[0086] In the following second to fourth embodiments, the shape and structure of the reinforced frame 200 and connecting frame 100 are the same as those described for the first embodiment, although there may be differences in arrangement, size, etc.

[0087] Figure 9 shows the side sill according to the second embodiment, and shows an exploded view of the connecting frame and reinforcement frame, excluding the side sill frame.

[0088] The side sill reinforcement structure 20 according to the second embodiment may include three connecting frames 100 and two reinforcement frames 200.

[0089] As an example, a plurality of reinforcing frames 200 are provided, and the second planar portion 213 of the first reinforcing frame 210, which is one of the plurality of reinforcing frames 200, contacts the first surface of the connecting portion 111, and the first planar portion 221 of the second reinforcing frame 220, which is one of the plurality of reinforcing frames 200 other than the first reinforcing frame 210, can contact the second surface of the connecting portion 121 which is parallel to the first surface.

[0090] According to the second embodiment, a third connecting frame 130, which is a connecting frame 100 provided between the first reinforcing frame 210 and the second reinforcing frame 220, can be further provided. Therefore, the side sill according to the second embodiment can be provided with the first connecting frame 110, the first reinforcing frame 210, the third connecting frame 130, the second reinforcing frame 220, and the second connecting frame 120 in sequence.

[0091] Unlike the first embodiment, in which the lower surface of the second planar portion 213 of the first reinforcing frame 210 and the upper surface of the first planar portion 221 of the second reinforcing frame 220 are in contact, the lower surface of the second planar portion 213 of the first reinforcing frame 210 is positioned in contact with the upper surface of the connecting portion 131 of the third connecting frame 130, and the upper surface of the first planar portion 221 of the second reinforcing frame 220 and the lower surface of the connecting portion 131 of the third connecting frame 130 can be positioned in contact.

[0092] This further increases rigidity against side impacts and provides the effect of strengthening the connection between the side sill frame 300 and the reinforced structure.

[0093] Figure 10 shows an exploded view of the side sill reinforcement structure according to the third embodiment.

[0094] The reinforced structure 30 according to the third embodiment may comprise two connecting frames 100 and one reinforced frame 200. A first reinforced frame 210, which is one reinforced frame 200, may be provided between the first connecting frame 110 and the second connecting frame 120.

[0095] The upper surface of the first flat portion 211 of the first reinforcing frame 210 can abut against the lower surface of the connecting portion 111 of the first connecting frame 110, and the lower surface of the second flat portion 223 of the first reinforcing frame 210 can abut against the upper surface of the connecting portion 121 of the second connecting frame 120, thereby joining them together.

[0096] In this case, while weight reduction is easier compared to the first or second embodiment, the connection between the side sill frame 300 and the reinforcing structure can provide a stronger effect.

[0097] Figure 11 shows an exploded view of the reinforced structure according to the fourth embodiment.

[0098] The side sill reinforcement structure 40 according to the fourth embodiment may comprise two reinforcement frames 200 and one connecting frame 100.

[0099] In this case, the structure is provided by a first reinforcement frame 210, a third connecting frame 130, and a second reinforcement frame 220, and the first connecting frame 110 can be joined to the side sill frame 300 by being joined at the central part of the hollow section S of the side sill frame 300.

[0100] The lower surface of the second flat portion 213 of the first reinforced frame 210 can be in contact with the upper surface of the connecting portion 131 of the third connecting frame 130, and the upper surface of the first flat portion 221 of the second reinforced frame 220 can be in contact with the lower surface of the connecting portion 131 of the third connecting frame 130. In this case, the shape can be adopted to increase the energy absorption capacity due to side impacts and to reduce weight.

[0101] In all embodiments of the present invention, joints between structures can be joined by welding or by applying structural adhesive, but various other joining methods such as rivets, self-piercing rivets, and flow-drill screws are also possible.

[0102] Furthermore, the embodiment is not limited to the above example, and the number of reinforced frames 200 and connecting frames 100, as well as their internal arrangement structure, can be varied.

[0103] Figure 12 shows the reinforcing structure included in the existing side sill.

[0104] The existing side sill reinforcement structure 50 extends in the longitudinal direction but does not have a connecting frame, and has a shape in which a reinforcement frame having a different unit structure from the present invention extends in the longitudinal direction of the side sill frame. In addition, the multiple reinforcement frames 510, 520 are not arranged in the vertical direction but are connected in the width direction, both internally and externally. Furthermore, the side sill frame and the reinforcement frames 510, 520 are directly joined together.

[0105] Figure 13 shows deformation due to a side impact in an existing side sill structure, and Figure 14 shows deformation due to a side impact in a side sill structure according to the first embodiment of the present invention, where (a) is before the impact and (b) shows the deformation after the impact.

[0106] Figures 13 and 14 show the second side sill frame or a corresponding configuration according to an embodiment of the present invention, excluding the latter. The internal structure of the first side sill frame is a schematic representation of a part of the battery frame, and the interior of the battery frame represents the battery space in which the electric vehicle battery is mounted.

[0107] Examining Figure 13(b), it can be seen that the reinforced structure of the side sill failed to adequately absorb the impact, resulting in deformation in the lower battery space. Therefore, the battery may be subjected to impact, potentially leading to safety problems.

[0108] In contrast, examining Figure 14(b) reveals that the reinforced structure is completely crushed, absorbing the impact sufficiently, and no deformation occurs in the battery space.

[0109] Specifically, in the side sill reinforcement structure according to the first embodiment of the present invention, when the mass is set to 15.1 kg, the amount of energy absorbed by a side impact (Total Internal Energy) is 27.2 kJ, and the amount of energy absorbed per unit mass (Total IE / Mass) is 1.80 kJ / kg. When such a side impact is applied, at a certain reference time, 45 ms after the impact, the displacement of the first side sill frame 310 in the section where the most inward deformation occurred was 52.5 mm, and the displacement of the second side sill frame 320 was 107.3 mm.

[0110] In comparison, for the reinforced structure shown in Figure 12, when the mass is set to 13.9 kg, the energy absorbed by a side impact is 22.8 kJ, and the energy absorbed per unit mass (Total IE / Mass) is 1.64 kJ / kg. When such a side impact is applied, at a certain reference time, 45 ms after the impact, the displacement of the first side sill frame in the section where the most inward deformation occurred was 51.3 mm, and the displacement of the second side sill frame was 104.0 mm.

[0111] According to the results described above, the reinforced structure according to the first embodiment of the present invention has a higher energy absorption per unit mass compared to existing reinforced structures, and despite a significant change in the displacement of the second side sill frame 320, the internal reinforced structure is effectively compressed, absorbing energy and causing the displacement of the second side sill frame 320 to change even more significantly than before, thus providing the effect of safely protecting the internal vehicle body structure, especially the battery in the case of electric vehicles.

[0112] Although the present invention has been described above, primarily in terms of examples, the present invention is not limited to the examples described above and can be modified and implemented by a person of the ordinary skill without any change in the technical idea of ​​the present invention as claimed in the claims. [Explanation of Symbols]

[0113] 10 Reinforcement structure of the first embodiment 20 Reinforcement structure of the second embodiment 30 Reinforced structure of the third embodiment 40 Reinforced structure of the fourth embodiment 50 Reinforced structure of existing examples 100 Connecting frame 101 Connecting section 102 First flange 103 Second flange 104 First through hole 110 First connecting frame 120 Second connecting frame 130 Third connecting frame 200 Reinforced frame 201 First plane part 202 First inclined part 203 Second plane part 204 Second inclined part 205 Second through hole 206 Third through hole 210 First Reinforced Frame 220 Second Reinforced Frame 300 Side sill frame 310 First side sill frame 320 Second side sill frame 330 Joint of side sill frame 400 Outer frame; 510, 520 Existing reinforced frame S Hollow section u Unit section θ Tilt angle

Claims

1. Side sill frame including hollow section; A connecting frame including a flange that is arranged in the longitudinal direction of the side sill frame in the hollow portion and joined to the side sill frame; and A vehicle side sill, comprising: a reinforcing frame arranged in the longitudinal direction of the side sill frame in the hollow portion, joined to the connecting frame, and having unit sections of varying height;

2. The vehicle side sill according to claim 1, wherein the connecting frame extends across the hollow portion and includes a connecting portion that contacts the reinforcing frame in at least a portion of the area.

3. The aforementioned side sill frame is The first side sill frame located on the inside of the vehicle; and A second side sill frame, which is joined to the first side sill frame and is provided on the outside of the vehicle; The side sill for a vehicle according to claim 2, wherein the flange of the connecting frame includes a first flange joined to the first side sill frame and a second flange joined to the second side sill frame.

4. The vehicle side sill according to claim 3, wherein the first flange and the second flange extend from the connecting portion, and the first flange and the second flange extend in different directions from each other in the height direction.

5. The vehicle side sill according to claim 4, wherein the first flange and the second flange are formed by bending.

6. The aforementioned unit interval is, The vehicle side sill according to claim 2, comprising a planar portion located parallel to the longitudinal direction of the side sill frame and including a first planar portion and a second planar portion located at a lower position than the first planar portion, and an inclined portion arranged at an inclination following the planar portion.

7. The vehicle side sill according to claim 6, wherein the angle formed by the extension of the first planar portion and the inclined portion, and the angle formed by the extension of the second planar portion and the inclined portion, are 40° to 80°.

8. Multiple of the aforementioned reinforced frames are provided, The second planar portion of the first reinforcing frame, which is one of the multiple reinforcing frames, and the first planar portion of the second reinforcing frame, which is one of the multiple reinforcing frames that is not the first reinforcing frame, are in contact. The vehicle side sill according to claim 6, wherein the length of the unit section of the first reinforced frame and the second reinforced frame is the same.

9. Multiple of the aforementioned reinforced frames are provided, The second planar portion of the first reinforcing frame, which is one of the multiple reinforcing frames, is in contact with the first surface of the connecting portion. The vehicle side sill according to claim 6, wherein the first planar portion of the second reinforcing frame, which is one of the plurality of reinforcing frames other than the first reinforcing frame, is in contact with a second surface parallel to the first surface of the connecting portion.

10. Multiple of the aforementioned connecting frames are provided, A vehicle side sill according to claim 6, wherein a first connecting frame, which is one of the plurality of connecting frames, is in contact with the first planar portion, and a second connecting frame, which is one of the plurality of reinforcing frames that is not the first connecting frame, is in contact with the second planar portion.

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

12. The vehicle side sill according to claim 1, wherein the reinforced frame or the connecting frame is made of a single steel plate.

13. Multiple first through holes are formed in the connecting portion. A vehicle side sill according to claim 6, wherein some of the plurality of first through holes are located in the same longitudinal and width directions as the second through holes formed in the first flat portion, and other parts of the plurality of first through holes are located in the same longitudinal and width directions as the third through holes formed in the second flat portion.

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