Vehicle body

Abstract

A vehicle body according to one embodiment of the present invention includes a side sill extending along the length of the vehicle; and a cross member extending along the width of the vehicle, the cross member having an end connected to the side sill, the side sill including an inner panel; an outer panel connected to the inner panel; and a reinforcement material disposed between the inner panel and the outer panel, the inner panel including an inclined surface formed so as to have a greater inclination from the inside to the outside of the vehicle, the end of the cross member being formed so as to be inclined corresponding to the inclined surface and being connected to an outer surface of the inclined surface, and one side end of the reinforcement material being connected to an inner surface of the inclined surface.

Description

Technical Field

[0001] The present invention relates to a vehicle body capable of improving the response performance during a side collision of a vehicle.

Background Art

[0002] To protect against impacts from the side of a vehicle, the vehicle body includes side sills and cross members. Among the cross members, for example, the seat cross member is a member for fixing the seat frame, but can also play a role in supporting the impact load from the side.

[0003] When a large-capacity battery is installed, such as in an electric vehicle, it is necessary to secure as much space as possible under the floor. However, doing so results in a shortage of installation space for members that can absorb collision energy, making the vehicle vulnerable to side collisions.

[0004] To solve this problem, additional reinforcing members are introduced inside the side sills to improve the energy absorption capacity, and the cross members are strengthened to suppress the inflow into the passenger compartment of the side sills to the maximum extent.

[0005] Therefore, it is required to ensure a strengthened connection structure between the side sills and the cross members connected to the side sills. In particular, when applying ultra-high-strength steel of, for example, 780 MPa or more, the connection structure between the cross members and the side sills has a very limited shape due to low formability.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The object of the present invention is to provide a vehicle body that improves the connection structure between the side sill and the cross member, and can minimize the penetration of the collision load into the passenger space and the battery space during a side collision of the vehicle.

Means for Solving the Problems

[0008] A vehicle body according to an embodiment of the present invention includes a side sill extending along the longitudinal direction of the vehicle; and a cross member extending along the width direction of the vehicle and having ends coupled to the side sill. The side sill includes an inner panel; an outer panel coupled to the inner panel; and a reinforcing member disposed between the inner panel and the outer panel. The inner panel includes an inclined surface formed to have an increasing inclination from the inside to the outside of the vehicle. The ends of the cross member are formed to be inclined corresponding to the inclined surface and are coupled to the outer surface of the inclined surface. One end portion of the reinforcing member can be coupled to the inner surface of the inclined surface.

Effects of the Invention

[0009] According to the present invention, during a side collision of the vehicle, energy can be absorbed by the side sill and the reinforcing member inside it, and the load can be directly transmitted to the cross member through the reinforcing member, minimizing the penetration of the collision load into the passenger space and the battery space.

[0010] Also, according to the present invention, the connection structure between the side sill and the cross member is strengthened, and the cross member can receive and support a high load during a side collision of the vehicle. As a result, the effect of increasing the rigidity of the vehicle body can be obtained.

[0011] Furthermore, according to the present invention, when manufacturing the cross member with an ultra-high-strength steel of, for example, 780 MPa or more, the flange at the end can be formed without notches due to the inclined shape at the end, and there is an advantage that the weight of the vehicle body can be reduced.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

[0013] The present invention proposes an organic connection relationship between a side sill, a cross member, and a reinforcing member inside the side sill, and can not only efficiently support a collision load entering from the side of the vehicle, but also provide a vehicle body that can increase the connection rigidity and reduce the weight.

[0014] Hereinafter, the present invention will be described in detail with reference to exemplary drawings. When adding reference numerals to the components of each drawing, it should be noted that for the same components, as far as possible, the same numerals are used even if they are shown on other drawings.

[0015] In the following description, terms such as "front", "side", "rear", "front", "rear", "up", "down", "left and right", "inner", "outer", "inside", "outside", etc. used in relation to directions are defined based on the vehicle or the vehicle body.

[0016] In this specification, the vehicle means various vehicles that move a transported object such as a person, an animal, or an object from a starting point to a destination. Such vehicles are not limited to only vehicles running on roads or routes.

[0017] FIG. 1 is a perspective view showing a vehicle body according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an enlarged view of part A in FIG. 1, and FIG. 3 is a perspective view showing an enlarged view of the cross member shown in FIG. 1.

[0018] The skeletal structure of the vehicle body can be composed of side members extending in the longitudinal direction X of the vehicle and constituting the side surface of the vehicle body, and a plurality of cross members extending in the width direction Y of the vehicle and coupled to the side members on both sides.

[0019] The plurality of cross members are coupled to the side members with a space therebetween from the front end to the rear end of the vehicle body. Among the plurality of cross members 2, for example, the seat cross member can be used to fix the seat frame.

[0020] The side member can include a side sill 1 that protects the passenger space during a side collision and forms the outer shape of the vehicle side.

[0021] In this way, the vehicle body is in a form in which a plurality of members intersect and are coupled with respect to the longitudinal direction X and the width direction Y of the vehicle. Depending on the connection rigidity between the intersecting members, the energy transmitted during a collision is evenly transmitted and dispersed throughout the vehicle body, or conversely, broken, resulting in a concentration of collision energy and serious deformation and damage, which may cause great injury to the passengers.

[0022] Therefore, the connection rigidity between the intersecting members becomes a very important factor in ensuring the overall rigidity of the vehicle body and the safety of the passengers.

[0023] For example, a battery case (not shown) can be mounted in the center of the vehicle body. For this purpose, a battery space for mounting the battery case can be provided in the vehicle body. The battery case can include a plurality of battery cells capable of charging and discharging.

[0024] A floor panel 3 that partitions the passenger space where passengers board can be provided on the battery case. For example, a plurality of cross members 2 such as seat cross members can be fixed to the floor panel.

[0025] As shown in FIGS. 1 to 2, the vehicle body according to an embodiment of the present invention can include a side sill 1 and a cross member 2.

[0026] The side sill 1 can be formed and arranged to extend along the vehicle length direction X at the lower parts on both left and right sides of the vehicle body.

[0027] For example, the side sill 1 can include an inner panel 10 and an outer panel 20, and the side sill can be integrally joined by welding the inner panel and the outer panel to each other at its lower end or upper end. By joining the inner panel to the floor panel 3, the side sill can be provided on the vehicle body.

[0028] The side sill 1 can be made of a metal material such as steel, and can be formed by forming using press, bending, roll forming, or a combination thereof.

[0029] The impact performance of the side sill 1 can be ensured by adjusting the material of the plate material forming the side sill and the strength or thickness of this material. For example, by adopting ultra-high strength steel of 780 MPa or more, an optimal combination for weight reduction of the side sill can be achieved.

[0030] More specifically, the side sill l can be made of a plate material such as 1470 MART (Martensitic) steel or 1470 HPF (Hot Press Forming) steel with a thickness of about 1.4 mm to 1.6 mm produced by the applicant.

[0031] Here, 1470 MART steel has a tensile strength of 1,470 MPa or more and a yield strength of 1,050 MPa or more, and is a steel type with improved collision safety. 1470 HPF steel is a steel type that can freely create the form of parts while obtaining a tensile strength of 1,470 MPa or more.

[0032] The inner panel 10 can include an inclined surface 11 formed to have an increasing inclination from the inside to the outside. The inclined surface can be formed at a position higher than half the height of the inner panel. Such an inclined surface can be inclined at an angle θ of about 8 to 20 degrees with respect to a vertical line V extending in the vehicle height direction Z.

[0033] Furthermore, the inner panel 10 can include a stepped portion 12 extending from the inside to the outside and bent. The stepped portion can be formed at a position lower than half the height of the inner panel.

[0034] The side sill 1 acts as an important vehicle body structure for coping with frontal, rear, and side collisions of the vehicle. Optionally, when the inside of the side sill is empty, buckling is likely to occur under various collision conditions, so various forms of reinforcement means can be supplemented inside the side sill.

[0035] The side sill 1 of the vehicle body according to an embodiment of the present invention can include a reinforcing member 30 disposed between the inner panel 10 and the outer panel 20. For example, the reinforcing member can be formed by bending a single plate material.

[0036] After extending to a predetermined length and then being bent repeatedly to form a desired number of flat surfaces, both ends of the plate material can be bent clockwise or counterclockwise so as to form flanges.

[0037] One side end portion of the reinforcing member 30, that is, the upper flange, can be coupled to the inner surface of the inclined surface 11 formed on the inner panel 10. The upper flange can be coupled by welding such as spot welding, laser welding, or arc welding using carbon dioxide on the inner surface of the inclined surface.

[0038] The other end of the reinforcing member 30, i.e., the lower flange, can be joined to the inner surface of the inner panel 10. The lower flange can be joined to the inner surface of the inner panel by welding such as spot welding, laser welding, or arc welding using carbon dioxide or the like.

[0039] The remaining flat surfaces of the reinforcing member 30 that come into contact with the inner panel 10 or the outer panel 20 can be fixed by an adhesive or welding or the like.

[0040] The reinforcing member 30 can be made of a metal material such as a steel material, and can be formed by forming, bending, roll forming using a press, or a combination thereof.

[0041] The reinforcing member 30 can be made of a sheet material such as 1180 TRIP (Transformation Induced Plasticity) steel with a thickness of about 0.9 mm to 1.1 mm produced by the applicant.

[0042] Here, 1180 TRIP steel is a steel type with an improved elongation rate while ensuring a tensile strength of 1180 MPa or more and a yield strength of 850 MPa or more.

[0043] The reinforcing member 30 can include a first reinforcing member 31 joined to the inner panel 10 and a second reinforcing member 32 joined to the outer panel 20. As shown in FIG. 2, the first reinforcing member and the second reinforcing member can be formed by bending a single sheet material so as to be twisted.

[0044] After extending to a predetermined length and then being bent, the method of repeating the bending is repeated until a desired number of flat surfaces are formed, and then both ends of the sheet material can be bent clockwise or counterclockwise so as to form flanges.

[0045] The first reinforcing member 31 and the second reinforcing member 32 can have a length that substantially fills the inside of the side sill 1 in the vehicle length direction X.

[0046] Since the first reinforcing member 31 and the second reinforcing member 32 have a shape that is bent multiple times, it becomes possible to ensure rigidity not only against the collision energy acting on the side of the side sill 1 but also against the collision energy acting in the front-rear direction.

[0047] The first reinforcing member 31 and the second reinforcing member 32 can be partially in contact with each other and fixed. For this purpose, the first reinforcing member and the second reinforcing member can have a length in the vehicle width direction Y that can divide the space between the inner panel 10 and the outer panel 20.

[0048] Also, the contact surfaces where the first reinforcing member 31 and the second reinforcing member 32 are in contact with each other can be located so as to extend parallel to the vertical line V extending in the vehicle height direction Z so that the collision load between them can be accurately transmitted and responded to.

[0049] The flat surface P1 and the flange F of the first reinforcing member 31 can be joined to the inner panel 10 by welding such as spot welding, laser welding, or arc welding using carbon dioxide or the like. As a result, a welded portion can be formed on the flat surface P1 and the flange.

[0050] One side end portion of the first reinforcing member 31, that is, the upper flange F, can be joined to the inner surface of the inclined surface 11 formed on the inner panel 10.

[0051] The other side end portion of the first reinforcing member 31, that is, the lower flange F, can be joined to the inner surface of the inner panel 10.

[0052] The flat surface P2 and the flange F of the second reinforcing member 32 can be joined to the outer panel 20 by welding such as spot welding, laser welding, or arc welding using carbon dioxide or the like. As a result, a welded portion can be formed on the flat surface P2 and the flange.

[0053] Also, when the first reinforcing member 31 and the second reinforcing member 32 come into contact with each other, an adhesive can be interposed between the flat surface P3 of the first reinforcing member and the flat surface P4 of the second reinforcing member, and they can be joined to each other to form an adhesive portion.

[0054] Further, the flat surface P5 of the second reinforcing member 32 can be fixed to a wall surface extending in the vehicle height direction Z at the stepped portion 12 of the inner panel 10. For this purpose, an adhesive can be interposed between the flat surface P5 of the second reinforcing member and the wall surface of the stepped portion, and they can be joined to each other.

[0055] The reinforcing material configured and arranged in this way can accurately transmit the collision load received by the outer panel 20 of the side sill 1 to the inner panel 10 and then to the cross member 2.

[0056] The cross member 2 can be formed and arranged to extend in the vehicle width direction Y and connect the side sills 1 on both sides.

[0057] The cross member 2 can be coupled to one side surface of the side sill 1. More specifically, the end portion of the cross member can be formed to be inclined corresponding to the inclined surface 11 of the inner panel 10 of the side sill and can be coupled to the outer surface of the inclined surface.

[0058] First flange surfaces 41 can be formed without notches at both side end portions located at both ends of the length portion of the cross member 2.

[0059] If a notch is applied to the first flange surface, there is a drawback that the first flange surface that contacts and is welded to the side sill 1 becomes small, so the load transmitted to the cross member 2 also becomes relatively small. Therefore, it is much more preferable that the first flange surface 41 is formed without notches.

[0060] The first flange surface 41 can be inclined corresponding to the inclined surface 11 of the inner panel 10 of the side sill 1. The first flange surface can be joined to the outer surface of the inclined surface of the inner panel by welding such as spot welding, laser welding, arc welding using carbon dioxide, etc.

[0061] The cross member 2 can be provided as a tubular member having, for example, a hollow portion with an empty interior and a cross-sectional shape of a polygon with four or more sides, but is not necessarily limited to this, and can be formed by being bent to have an open cross-section, a member made of a single plate material having a curved cross-sectional shape, or a member formed by joining two or more plate materials.

[0062] As shown in FIGS. 3 and 4, the cross-section of the cross member 2 of the vehicle body according to an embodiment of the present invention can include a pair of wall surfaces 43 extending in the vehicle height direction Z and a connecting surface 44 connecting one ends of these wall surfaces. Also, the other ends of the wall surfaces can be bent to form a second flange surface 42 for connecting the cross member to the floor panel 3. Thereby, the cross member can have a hat-shaped cross-sectional shape.

[0063] The cross member 2 can be formed of one plate material. For example, by adopting a plate material made of ultra-high strength steel of 780 MPa grade or higher, an optimal combination for weight reduction in addition to rigidity addition can be achieved.

[0064] Alternatively, the cross member 2 can be made of plate materials of different materials for the intermediate portion 45 and both side end portions 46.

[0065] The intermediate portion 45 of the cross member 2 can be made of a plate material such as 1470 MART steel having a thickness of about 1.5 mm to 1.6 mm produced by the applicant.

[0066] Both side end portions of the cross member 2 can be made of plate materials such as 1180 TRIP steel having a thickness of about 1.8 mm to 1.9 mm or 1470 HPF steel having a thickness of about 1.8 mm to 1.9 mm produced by the applicant.

[0067] Thus, the middle portion 45 of the cross member 2 can have a strength equal to or greater than that of the both side end portions 46. The middle portion of the cross member can have a thickness equal to or less than that of the both side end portions.

[0068] The middle portion 45 of the cross member 2 can be formed by, for example, roll forming or the like, and the both side end portions 36 can be formed by, for example, press forming. Thereafter, the middle portion and the both side end portions can be joined to each other by welding to form an integrated cross member. In FIG. 3, a reference numeral 47 indicates a weld line.

[0069] Furthermore, a bead portion 48 extending along the longitudinal direction of the cross member 2 can be formed on the connecting surface 44 of the cross member 2. The bead portion can be formed by a concave channel or a convex protrusion.

[0070] The depth or height of the bead portion 48, in other words, the depth of the channel or the height of the protrusion can be varied, and the depth of the channel can be made shallower or the height of the protrusion can be made lower as approaching the end portion of the cross member 2.

[0071] Specifically, in the middle portion 45 of the cross member 2, the bead portion 48 formed on the connecting surface 44 has a constant depth or height (see (a) of FIG. 4).

[0072] At the end portion 46 of the cross member 2, the depth or height of the bead portion 48 is varied, and the depth of the channel becomes shallower or the height of the protrusion becomes lower as the end portion 46 of the cross member 2 is farther from the middle portion 45 (see (b) and (c) of FIG. 4).

[0073] Thereby, in the middle portion 45 of the cross member 2, the connecting surface 44 can have a substantially M-shaped cross-sectional shape, and at the both side end portions 46, the connecting surface can gradually become flat to have a simple hat-shaped cross-sectional shape.

[0074] By forming the bead portion 48 in this way, the middle portion 45 of the cross member 2 can reinforce the rigidity against the collision load entering in the longitudinal direction of the cross member, and both side end portions 46 can be easily formed on the first flange surface 41 without bending at the connection surface 44 and without notches at the ends.

[0075] Also, as described above, the end portion 46 and the first flange surface 41 of the cross member 2 can be formed to be inclined at an angle θ of about 8 to 20 degrees with respect to the vertical line V extending in the vehicle height direction Z so as to correspond to the inclined surface 11 of the inner panel 10.

[0076] When the angle θ of the inclined surface 11 is less than 8 degrees, it is difficult to form the first flange surface 41 at the end portion 46 of the cross member 2 without notches. When it exceeds 20 degrees, not only can the collision load not be accurately transmitted to the cross member during a side collision of the vehicle, but it is also disadvantageous for the reinforcing member 30 or the first reinforcing member 31 to support the collision load.

[0077] As a result, the end portion 46 of the cross member 2 can have a continuous first flange surface 41 without notches even though it is made of ultra-high strength steel of 780 MPa or more.

[0078] The inclined first flange surface 41 at the end portion 46 of the cross member 2 and the inclined surface 11 formed on the inner panel 10 of the side sill 1 are inclined at the same angle θ with respect to each other, so that the contact between them can be perfectly matched.

[0079] In this way, since the end portion 46 of the cross member 2 is in complete contact and connection with the inner panel 10 of the side sill 1, the side sill can reliably transmit the collision load to the cross member.

[0080] Such a cross member 2 enables weight reduction of the vehicle body while maintaining the warpage and bending rigidity of the vehicle body after being combined with both side sills 1.

[0081] The above description merely exemplarily explains the technical idea of the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various modifications and variations without departing from the essential characteristics of the present invention.

[0082] Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to explain it. The scope of the technical idea of the present invention is not limited by such embodiments. The protection scope of the present invention should be interpreted according to the following claims, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

Description of Reference Numerals

[0083] 1 Side sill 2 Cross member 3 Floor panel 10 Inner panel 11 Inclined surface 12 Step portion 20 Outer panel 30 Reinforcement 31 First reinforcing member 32 Second reinforcing member 41 First flange surface 42 Second flange surface 43 Wall surface 44 Connecting surface 45 Intermediate portion 46 End portion 48 Bead portion

Claims

1. A side sill extending along the longitudinal direction of the vehicle, a cross member extending along the width direction of the vehicle and having ends coupled to the side sill, and the side sill includes an inner panel, an outer panel coupled to the inner panel, and a reinforcing member disposed between the inner panel and the outer panel, wherein the inner panel includes an inclined surface formed to have an increasing inclination from the inside to the outside of the vehicle, ends of the cross member are formed to be inclined corresponding to the inclined surface and are coupled to an outer surface of the inclined surface, one side end of the reinforcing member is coupled to an inner surface of the inclined surface, the ends of the cross member and one side end of the reinforcing member face each other, the reinforcing member is formed by alternately bending a single plate material extending along the height direction and the longitudinal direction of the vehicle clockwise or counterclockwise along an axis in the longitudinal direction, the reinforcing member includes a first reinforcing member coupled to the inner panel, and a second reinforcing member coupled to the outer panel, wherein one side end of the first reinforcing member is coupled to the inner surface of the inclined surface, the first reinforcing member and the second reinforcing member are partially in contact with each other and fixed, a vehicle body.

2. The vehicle body according to claim 1, wherein the inclined surface is inclined at an angle between 8 and 20 degrees with respect to a vertical line extending in the height direction of the vehicle.

3. The vehicle body according to claim 1, wherein a contact surface where the first reinforcing member and the second reinforcing member are in contact with each other extends parallel to a vertical line extending in the height direction of the vehicle.

4. The vehicle body according to claim 1, wherein the ends of the cross member include a first flange surface formed without a notch.

5. The vehicle body according to claim 4, wherein the first flange surface is inclined at the same angle as the inclined surface and is in contact with and coupled to the outer surface of the inclined surface.

6. The cross member includes a pair of wall surfaces extending in the height direction of the vehicle, and a connecting surface connecting one ends of the pair of wall surfaces, wherein the other ends of the wall surfaces are bent to form a second flange surface, the vehicle body according to claim 5.

7. A bead portion extending along the longitudinal direction of the cross member is disposed on the connecting surface of the cross member, the vehicle body according to claim 6, wherein the bead portion is formed such that a depth or height of the bead portion is variable.

8. The vehicle body according to claim 7, wherein the cross member is made of plate materials of different materials for an intermediate portion and both side end portions, and then joined to each other by welding.

9. The vehicle body according to claim 8, wherein the intermediate portion of the cross member has a strength equal to or higher than the strength of both side end portions and a thickness equal to or less than the thickness of both side end portions.

10. In the intermediate portion, the bead portion has a certain depth or height. The vehicle body according to claim 8, wherein in both side end portions, the depth of the bead portion becomes shallower or the height of the bead portion becomes lower as the distance from the intermediate portion increases.

11. The vehicle body according to any one of claims 1 to 10, wherein the side sill and the cross member are made of a plate material made of an ultra-high strength steel of 780 MPa or more.

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