Electric car body

Abstract

The present invention relates to a body of an electric vehicle that can minimize penetration of collision loads into passenger spaces and battery spaces during a front or rear collision, and includes a front side member connected to a front bumper beam on one side and branching off on the other side to include a first branch portion and a second branch portion; a first front cross member connected to the first branch portion and the second branch portion; a side seal connected to the second branch portion; a front subframe connected to the front side member; and a battery case including a reinforcing member extending along the length of the vehicle body and connected to the side seal and the first front cross member, wherein a connection position between the first branch portion and the first front cross member and a first connection position between the first branch portion and the front subframe may overlap a virtual cross section of the reinforcing member extending in the length direction of the vehicle body.

Description

[Technical field]

[0001] The present invention relates to a body of an electric vehicle capable of efficiently coping with a collision from the front or rear. [Background technology]

[0002] In the event of a collision, a vehicle must absorb as much of the collision energy as possible at the front or rear, minimizing the transfer of load to the space where passengers sit or, in the case of electric vehicles, the space where the battery is installed.

[0003] For this reason, the anti-intrusion zone of the body, which must suppress the penetration of collision loads and prevent deformation, must be designed to be strong, but in the case of electric vehicles, the components surrounding the battery space must be made of very strong and thick materials, which increases the weight of the vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5698581 specification Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a body of an electric vehicle that can minimize the penetration of collision loads into the passenger space and the battery space during a front or rear collision. [Means for solving the problem]

[0006] The body of an electric vehicle according to one embodiment of the present invention includes a front side member having a first branch portion and a second branch portion formed by branching off on the other side; a first front cross member extending along the width direction of the vehicle body and connected to the first branch portion and the second branch portion; a side seal extending along the length direction of the vehicle body and connected to the second branch portion; a front subframe connected to the front side member; and a battery case including a reinforcing member extending along the length direction of the vehicle body and connected to the first front cross member and the side seal, wherein a connecting position where the first branch portion and the first front cross member are connected and a first engagement position where the first branch portion and the front subframe are connected may overlap with a virtual cross section extending in the length direction of the vehicle body.

[0007] The body of an electric vehicle according to another embodiment of the present invention includes a rear side member having one side connected to a rear bumper beam; a first rear cross member extending along the width direction of the vehicle body and connected to the rear side member; a side seal extending along the length direction of the vehicle body and connected to the rear side member; a rear subframe connected to the rear side member on one side and to the first rear cross member on the other side; and a reinforcing member extending along the length direction of the vehicle body and a battery case connected to the first rear cross member and the side seal, and a fourth connecting position where the rear subframe and the first rear cross member are connected may overlap with a virtual cross section extending in the length direction of the vehicle body. Effect of the Invention

[0008] According to the present invention, the reinforcing member of the battery case is configured to act as a path for the collision load and as a direct load support member, thereby distributing the load across the vehicle body during a frontal or rear collision, thereby efficiently suppressing the penetration and deformation of the collision load and reducing weight. [Brief description of the drawings]

[0009] [Figure 1]1 is an exploded perspective view showing a body of an electric vehicle according to an embodiment of the present invention; [Diagram 2] 1 is a bottom view showing a body of an electric vehicle according to an embodiment of the present invention, illustrating a state before a battery case and a subframe are attached; [Diagram 3] 1 is a side view showing a body of an electric vehicle according to an embodiment of the present invention, in a state before a battery case and a subframe are attached; [Figure 4] 1 is a bottom view showing a body of an electric vehicle according to an embodiment of the present invention, with a battery case and a subframe attached; [Diagram 5] FIG. 5 is a cross-sectional view taken along line AA in FIG. 4, showing the battery case and the subframe attached. [Figure 6] 4 is an enlarged perspective view showing a connection between a first front cross member and a battery case in a body of an electric vehicle according to an embodiment of the present invention. FIG. [Figure 7] 4 is an enlarged perspective view showing a connection between a first front cross member and a battery case in a body of an electric vehicle according to an embodiment of the present invention. FIG. [Figure 8] FIG. 5 is a diagram corresponding to FIG. 4 for explaining a path of a collision load. [Figure 9] FIG. 6 is a diagram corresponding to FIG. 5 for explaining a path of a collision load. [Figure 10] 6 is an enlarged view of a portion of FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The vehicle body can be designed with an energy absorption zone that absorbs the maximum amount of collision energy during a front or rear collision, as well as a non-penetration zone that limits the penetration of collision load into the passenger space and battery space and prevents deformation.

[0011] The energy absorption area is designed to be relatively weak to induce deformation and prevent the collision load from being transmitted to the non-permeable area, while the non-permeable area must be designed to be relatively strong to prevent deformation and protect the passenger space and the battery space.

[0012] The most efficient way to achieve this is to increase the number of load support members to distribute the load, but in the case of conventional electric vehicles, the non-permeable areas are the spaces where the batteries are to be installed, so load support members cannot be configured and deformation must be prevented only by the members surrounding the battery space.

[0013] In order for the components surrounding the battery space to support collision loads and suppress penetration, as mentioned above, it is necessary to use very strong and thick materials for these components, which causes an increase in the weight of the vehicle body.

[0014] The present invention proposes a solution that deviates from the conventional concept described above and utilizes the battery case, which needs to be protected, as a load support member, thereby achieving the same effect as a configuration in which a load support member is arranged within a non-permeable area.

[0015] The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a schematic diagram of a semiconductor device according to an embodiment of the present invention;

[0016] In the following description, terms used in relation to directions, such as "forward," "front," "rear," "front and rear," "upper," "lower," "left and right," "inner," "outer," "inside," and "outside," are defined with reference to the vehicle or vehicle body.

[0017] In this specification, the electric vehicle refers to various vehicles that are powered by a battery and move objects to be transported, such as people, animals, and goods, from a starting point to a destination. Such vehicles are not limited to vehicles that run on roads or rails.

[0018] FIG. 1 is an exploded perspective view showing the body of an electric railcar according to one embodiment of the present invention, FIG. 2 is a bottom view showing the body of an electric railcar according to one embodiment of the present invention, FIG. 3 is a side view showing the state before a battery case and a subframe are attached, FIG. 4 is a bottom view showing the body of an electric railcar according to one embodiment of the present invention, and FIG. 5 is a cross-sectional view taken along line AA in FIG. 4 showing the state after the battery case and subframe are attached.

[0019] The vehicle body frame structure can be composed of side members that extend in the length direction X of the vehicle and form the sides of the vehicle body, and multiple cross members that extend in the width direction Y of the vehicle and are connected to the side members on both sides.

[0020] The multiple cross members are connected to the side members at intervals from the front end to the rear end of the vehicle body, and the side members may be called front side members 110, rear side members 210, etc. depending on the positions at which the cross members are connected or their positions relative to a floor panel (not shown). Meanwhile, a side seal 300 that protects the passenger space in the event of a side collision and defines the outline of the side may be provided on the side of the vehicle.

[0021] 1, a battery case 400 may be mounted in the middle of the body of an electric vehicle according to an embodiment of the present invention, and for this purpose, a battery space 40 in which the battery case is mounted may be provided in the body of the electric vehicle. The battery case may be formed to include a plurality of battery cells 401 that can be charged and discharged.

[0022] A floor panel that defines a passenger space in which passengers board can be provided above the battery space 40.

[0023] To facilitate understanding, FIG. 2 shows a non-permeable area 10 of the battery space 40 and the passenger space, and energy absorbing areas 20, 30 disposed before and after the non-permeable area.

[0024] As shown in more detail in FIGS. 2 to 5, the body of an electric vehicle according to an embodiment of the present invention may include a front side member 110, a first front cross member 120, a side seal 300, a front subframe 150, and a battery case 400.

[0025] The front side members 110 may be provided in a pair and may be disposed on both the left and right sides in the width direction Y of the vehicle body while extending along the length direction X of the vehicle body.

[0026] For example, the front side members 110 may be disposed so as to be inclined at an angle to the center line O extending in the longitudinal direction X of the vehicle body, rather than being parallel to the center line O. More specifically, the two front side members 110 may be disposed so as to approach each other toward the rear.

[0027] The inclined position of the front side member 110 is due to the fact that both ends of the front bumper beam 60 (see Figure 2) have a curvature toward the rear, and the collision load applied to the front side member is applied at an angle. By setting the angle of the front side member so that it is approximately parallel to the direction of the collision load in this manner, the collision load can be transmitted as much as possible.

[0028] In addition, the front side member 110 may be connected to the front bumper beam 60 such that one end connected to the front bumper beam 60, i.e., the center point of the front end portion, is located between 20% to less than 30% from the outer side to the inner side of the overall vehicle width.

[0029] For example, if the front side member 110 is connected to the front bumper beam 60 at a position corresponding to 25% from the outside to the inside of the overall vehicle width, the front side member can play a role in resisting the collision load in the event of a small overlap collision (when only 25% of the vehicle's overall width on the driver's or passenger's side collides with an obstacle at a speed of 64 km / h).

[0030] The front side member 110 can effectively transmit the collision load entering the front side member from the front bumper beam 60 to the vehicle body via the first front cross member 120, etc. Furthermore, in a small overlap collision, the front side member can play a role in eliciting behavior in the width direction Y of the vehicle.

[0031] For convenience, only one of the two front side members 110 will be described below. The other of the two front side members can be included and arranged symmetrically to the configuration of the front side member described.

[0032] The front side member 110 may include a front portion 111, and a first branch portion 112 and a second branch portion 113 branching off from the front portion.

[0033] The front part 111 is a linearly extending member that constitutes the front portion of the front side member 110. One end of the front part, i.e., the front end, can be connected to the front bumper beam 60, and the other end, i.e., the rear end, can be connected to the first branch part 112 and / or the second branch part 113, or the first branch part and the second branch part.

[0034] Such a front portion 111 may be formed of a tubular member having a cross-sectional shape such as a rectangle, but is not necessarily limited to this, and may be formed of a member made of a single plate material having a cross-sectional shape that is bent or curved to have an open cross-section, or a member made of two or more plates joined together.

[0035] The front portion 111 may be made of a metal material such as steel, and may be shaped by forming using a press, stamping, bending, roll forming, or a combination thereof.

[0036] More specifically, the front portion 111 may be made of a plate material such as 980 XF (EXtra Formability) steel having a thickness of about 1.5 mm to 1.7 mm produced by the present applicant. Here, 980 XF steel is a type of steel that has a tensile strength of 980 MPa or more, a yield strength of 600 MPa or more, and a high elongation rate.

[0037] The first branch portion 112 branches in a first direction from the other end of the front portion 111. The first branch portion may constitute a rear inner member of the front side member 110. Thus, one end of the first branch portion, i.e., a front end portion, may be connected to the other end of the front portion.

[0038] Such a first branch portion 112 may be formed of a tubular member having a cross-sectional shape such as a rectangle, but is not necessarily limited to this, and may be formed of a member made of a single plate material having a cross-sectional shape that is bent to have an open cross-section or a curved cross-sectional shape, or a member made of two or more plates joined together.

[0039] The other side of the first branch portion 112 may be connected to a front surface of a first front cross member 120 and a front surface of a dash panel 130 extending in a width direction Y of the vehicle body.

[0040] Also, the other side of the first branch portion 112 may be bent downward to form a curved portion 114 (see FIG. 5 ). The curved portion may come into contact with the front surface of the dash panel 130, and one side of an end of the curved portion may come into surface contact with the front surface of the first front cross member 120 and may be fixed, for example, by welding.

[0041] In the body of the electric vehicle according to an embodiment of the present invention, a coupling position P between the first branch portion 112 and the first front cross member 120 may be determined according to the number of divisions of the space inside the battery case 400.

[0042] For example, when the space within the battery case 400 is divided into thirds, the coupling position P of the first branch portion 112 and the first front cross member 120 can be aligned to correspond to a 1 / 3 point in the length in the width direction Y from a side frame 420 of the battery case, which will be described later. When the space within the battery case is divided into fourths, the coupling position of the first branch portion and the first front cross member can be aligned to correspond to a 1 / 4 point in the length in the width direction Y from the side frame of the battery case.

[0043] The first branch portion 112 may be molded continuously and integrally with the front portion 111 and extend linearly from the front portion. Although the drawings show an example in which the first branch portion extends linearly from the front portion, this is not necessarily a limitation. Due to this extended configuration, the first branch portion may have a cross-sectional shape corresponding to the cross-sectional shape of the front portion.

[0044] In the case where the first branch portion 112 extends linearly from the front portion 111, the second branch portion 113 can be fixed to the first branch portion or the front portion, for example by welding.

[0045] The second branch portion 113 branches off in a second direction different from the first direction from the other end of the front portion 111. The second branch portion may constitute a rear outer member of the front side member 110.

[0046] Also, the second branch portion 113 may be bent or curved to have a generally L-shape when viewed from above.

[0047] As a result, one side end of the second branch portion 113 can be fixed, for example by welding, to a side of the first branch portion 112, and the other side end of the second branch portion can be connected to the side seal 300 of the vehicle body and the first front cross member 120 extending in the longitudinal direction X of the vehicle.

[0048] More specifically, the other end of the second branch portion 113 is fixed, for example by welding, to the front surface of the side seal 300 and the front surface of the first front cross member 120 so as to contact the side seal and the first front cross member simultaneously.

[0049] The ends of the second branch portion 113 come into contact with the front surface and the underside of the first front cross member 120, so that the second branch portion can reliably transmit the collision load to at least the first front cross member.

[0050] Furthermore, an end of the second branch portion 113 comes into contact with the front surface of the side seal 300 and is fixed to the end of the side seal, and the second branch portion can also transmit the collision load to the side seal.

[0051] In the electric vehicle body according to the embodiment of the present invention, the front side member 110 is not limited to the above-mentioned configuration.

[0052] For example, the second branch portion 113 may be molded continuously and integrally with the front portion 111 and extend linearly following the front portion, while the first branch portion 112 may be fixed to the side of the second branch portion or the front portion, for example by welding.

[0053] In this manner, connecting the first branch portion 112 continuously and integrally with the front portion 111 or connecting the second branch portion 113 can be selected depending on whether more of the collision load is to be transmitted to either the first front cross member 120 or the side seal 300.

[0054] Alternatively, the front portion 111, the first branch portion 112, and the second branch portion 113 can be formed, and then connected and fixed to one another by, for example, welding, to manufacture the front side member 110. In such a case, there is an advantage in that the degree of freedom in assembly, dimensions, materials, etc. can be expanded in manufacturing the front side member.

[0055] The first branch portion 112 and the second branch portion 113 may be made of a metal material such as steel, and the front portion 111, the first branch portion 112, the second branch portion 113, the integrated front portion and first branch portion, or the integrated front portion and second branch portion may be formed using machining such as stamping, roll forming, etc.

[0056] More specifically, the first branch portion 112 and the second branch portion 113 may be made of a plate material such as 1470 HPF (Hot Press Forming) steel with a thickness of about 1.7 mm to 2.0 mm produced by the present applicant. Here, 1470 HPF steel is a type of steel that can obtain a tensile strength of 1,470 MPa or more and at the same time, can be freely shaped into parts.

[0057] The first branch portion 112 and the second branch portion 113 can be formed from a material having a strength higher than that of the front portion 111. In this manner, by combining the strengths of the plate materials forming the front side member 110, the impact absorbing ability of the front side member can be maximized.

[0058] In addition, the first branch portion 112 and the second branch portion 113 may be formed to be thicker than the front portion 111. In this manner, the branch portions which are relatively thicker than the front portion can strengthen the support rigidity of the front side member 110 itself during a frontal collision of the vehicle. As a result, the first branch portion and the second branch portion can maximize the impact absorption capacity of the front side member.

[0059] The first front cross member 120 extends in the width direction Y of the vehicle and is connected to the first branch portion 112 and the second branch portion 113 of the front side member 110, and extends in the length direction X of the vehicle to connect two side seals 300 that form the sides of the vehicle body.

[0060] The body of the electric vehicle according to an embodiment of the present invention may further include a second front cross member 140 extending in a width direction Y of the vehicle and connecting the front side members 110 on both sides.

[0061] The second front cross member 140 is located forward and above the first front cross member 120 and may be coupled to the first branch portions 111 of the front side members 110 on both sides.

[0062] The first and second front cross members 120, 140 may be provided, for example, as tubular members having a hollow interior and a cross-sectional shape that is a polygon having a square or more sides, but are not necessarily limited to this, and may be formed from a member made of a single plate material that is bent to have an open cross-section or has a curved cross-sectional shape, or a member made of two or more plate materials joined together.

[0063] After being joined to the front side members 110 on both sides, the first and second front cross members 120, 140 can be made lighter while maintaining the torsional and bending rigidity of the vehicle body.

[0064] The first and second front cross members 120, 140 are made of ultra-high strength steel, for example of 980 MPa class or higher, thereby achieving an optimum combination for adding rigidity to the front cross members while reducing their weight.

[0065] More specifically, the first and second front cross members 120, 140 may be made of a plate material such as 1470 MART (Martensitic) steel with a thickness of about 1.1 mm to 1.5 mm produced by the present applicant. Here, 1470 MART steel is a type of steel that has a tensile strength of 1,470 MPa or more and a yield strength of 1,050 MPa or more, improving collision safety.

[0066] In addition, the first front cross member 120 may have a greater thickness than the second front cross member 140 .

[0067] The side seals 300 may be formed and disposed at the lower portions of both the left and right sides of the vehicle body so as to extend along the longitudinal direction X of the vehicle.

[0068] For example, the side seal 300 may include a side seal inner panel and a side seal outer panel, and the side seal may be joined together by welding the side seal inner panel and the side seal outer panel at their lower or upper ends. The side seal may be provided on the vehicle body by joining the side seal inner panel to the floor panel.

[0069] The side seal 300 may be made of a metal material such as steel, and may be shaped by press forming, bending, roll forming, or a combination thereof.

[0070] The side seal 300 can ensure the collision performance of the side seal by adjusting the material of the plate material forming the side seal and the strength or thickness of this material. For example, by using ultra-high strength steel of 980 MPa class or more, an optimal combination for reducing the weight of the side seal can be achieved.

[0071] More specifically, the side seal 300 can be made of a plate material such as 1470 MART steel having a thickness of about 1.1 mm to 1.3 mm, produced by the present applicant.

[0072] The side seal 300 acts as an important vehicle body structure in response to front, rear and side collisions of the vehicle. Optionally, if the inside of the side seal becomes empty, buckling is likely to occur under various collision conditions, so various types of reinforcing means can be supplemented inside the side seal.

[0073] The front subframe 150 has a generally rectangular frame shape in which two horizontal members 151 formed to extend in the width direction Y of the vehicle are connected at both ends to two vertical members 152 formed to extend in the length direction X of the vehicle.

[0074] One of the cross members 151 may be provided with a mounting bracket for a steering gear box, and each end of the cross member may be provided with a mounting bracket for mounting one end of a suspension arm.

[0075] A first connecting bracket 153 extending in the longitudinal direction X of the vehicle may be provided at a rear end of the vertical member 152. The first connecting bracket has a bolt hole formed therein, and the first connecting bracket may be connected to an end of a first branch portion 112 of the front side member 110 by bolting.

[0076] Specifically, the first connecting bracket 153 may be bolted to the bottom surface from the end of the curved portion 144 of the first branch portion 112. The first connecting bracket and the end of the first branch portion form a first connecting position P1.

[0077] Because the first branch portion 112 and the first front cross member 120 are connected, the first connection position P1 between the first connecting bracket 153 and the end of the first branch portion 112 is located adjacent to the connection position P between the first branch portion and the first front cross member.

[0078] Furthermore, the vertical member 152 may be connected to the front side member 110 by bolting at the front end and the rear end, respectively. Here, the connection point with the rear end is a second connection position P2, and the connection point with the front end is a third connection position P3.

[0079] Alternatively, the second coupling position P2 may be located corresponding to a point where the first branch portion 112 and the second branch portion 113 of the front side member 110 branch off.

[0080] In this manner, the front subframe 150 is connected to the front side member 110 at a plurality of connection positions P, P1, and P2, i.e., six connection points, thereby increasing the rigidity of the connection portion and allowing the front subframe 150 to be stably attached to and supported by the front side member.

[0081] 6 and 7 are enlarged perspective views showing a connection between a first front cross member and a battery case in a body of an electric vehicle according to an embodiment of the present invention.

[0082] The battery case 400 has a substantially rectangular parallelepiped shape, and can house a plurality of battery cells 401 therein.

[0083] The battery case 400 may include a case body 402 and a cover (not shown). The case body and the cover may be coupled to each other to form a space inside.

[0084] The cover may be made of high-strength plastic or light metal such as aluminum, which can ensure sufficient strength while reducing weight and costs. If the material is plastic, the cover may be formed by injection molding or compression molding, and if the material is metal, the cover may be formed into a predetermined shape by pressing.

[0085] The case body 402 may be directly exposed to the outside and is highly susceptible to damage and breakage caused by external foreign objects, so it may be made of metal to more effectively protect the battery cells 401.

[0086] In such a case, the case body 402 can be made by preparing components by machining a material such as a steel material having a suitable strength, for example, an ultra-high strength steel material having a tensile strength of about 980 MPa or more for weight reduction, and then assembling and bonding these components.

[0087] For convenience, the battery case 400 will be described below with the case main body 402 at the center.

[0088] The case body 402 may include a plurality of bottom plates 410 , side frames 420 , and at least two reinforcing members 430 .

[0089] The bottom plate 410 is a flat plate made of metal such as steel. In the case body 402, the bottom plate can act as a member for supporting the battery cells 401.

[0090] The height dimension of the side frame 420 may be changed in accordance with the size of the battery cell 401 built into the case body 402. In addition, a plurality of fastening holes 421 for coupling with the cover may be formed on the upper surface of the side frame.

[0091] At least four side frames 420 are provided surrounding the multiple bottom plates 410, and both ends of each side frame are cut at a predetermined angle (e.g., about 45 degrees), and can be joined to corresponding other side frames at their respective ends and then joined by welding, such as arc welding or laser welding.

[0092] For example, the side frame 420 may be formed to have a generally rectangular closed cross section using a metal such as steel. In the case body 402, the side frame may constitute a side wall.

[0093] In this manner, the side frame 420 forms a “ring” (a form that does not break and is strongly connected) that defines a non-permeable area of ​​the vehicle body, thereby preventing the penetration of collision loads into the interior of the battery case 400.

[0094] The front and rear side frames 420 may be recessed in the height direction Z from the bottom surface at a predetermined position, and a coupling groove 422 may be formed that penetrates across the width direction of the front and rear side frames (e.g., the X direction in the drawing).

[0095] The coupling groove 422 may be formed with a shape corresponding to the cross-sectional shape of the reinforcing member 430, so that the ends of the reinforcing member may fit together when sandwiched in the coupling groove.

[0096] The bottom plate 410 and the side frame 420 can be joined together by welding such as arc welding. The bottom plate can be welded to the bottom surface of the side frame. This allows the case body 402 to have an internal space due to the side frame forming a closed cross section around the multiple bottom plates.

[0097] In the case body 402 of the battery case 400, a mounting frame 440 required for fixing the battery case to a vehicle body may be coupled to a surface constituting an outer surface of the battery case, which is the side frame 420. For example, a flange may be formed on the mounting frame, and the flange of the mounting frame may be welded to the outer surface of the side frame by arc welding or the like.

[0098] However, the mounting frame 440 may be attached to the front and rear side frames 420 apart from the portions where the coupling grooves 422 are formed.

[0099] The mounting frame 440 can be fixed, for example, to the first front cross member 120 of the vehicle body, the side seal 300, and a first rear cross member 220 (described later) by bolting or the like, thereby allowing the battery case 400 to be fixed to the vehicle body.

[0100] In addition, the mounting frame 440 can act as a member of the battery case 400 that first responds to the collision during a collision.

[0101] The reinforcing member 430 may include a lower reinforcing member 431 and an upper reinforcing member 432 coupled to an upper portion of the lower reinforcing member. The reinforcing member may extend over the entire length of the case body 402 along the longitudinal direction X.

[0102] The lower stiffener 431 and the upper stiffener 432 may be formed by machining a single sheet of metal, such as steel, etc. The stiffeners may be shaped by bending or roll forming, etc.

[0103] For example, when the reinforcing members 431 and 432 are manufactured by roll forming, it is possible to easily form ultra-high strength steel material with a tensile strength of about 980 MPa or more. Furthermore, roll forming has the advantage that it is easier to correct springback than press forming, and the corner radius of the reinforcing members can be made smaller.

[0104] More specifically, the lower reinforcement member 431 and the upper reinforcement member 432 can be made of a plate material such as 1470 MART steel having a thickness of about 0.9 mm to 1.1 mm produced by the present applicant.

[0105] The lower reinforcing member 431 may have a generally hat-shaped cross section formed by bending a single plate material having a predetermined width and length multiple times, so that the lower reinforcing member may be formed in a generally inverted U shape and may have flanges 433 at both ends in the width direction Y.

[0106] The lower reinforcement member 431 may be disposed between the plurality of bottom plates 410 and coupled to the bottom plates located on both sides in the width direction Y. The flange of the lower reinforcement member and the end of the bottom plate may be tightly joined to each other by welding, such as arc welding or laser welding.

[0107] Both ends of the lower reinforcement 431 in the length direction X can be joined to the front and rear side frames 420 by meeting with the front and rear side frames. As described above, the joining grooves 422 are formed at the joining portions of the front and rear side frames that meet with the ends of the lower reinforcement, and the ends of the lower reinforcement can be sandwiched in the joining grooves to join their shapes.

[0108] Here, the front and rear side frames 420 may be seated on the flanges 433 of the lower reinforcement 431, while the ends of the lower reinforcement may penetrate the front and rear side frames in a width direction (e.g., the X direction in the drawing) and protrude from the front and rear side frames, i.e., from the outer surfaces of the battery case 400.

[0109] The reason why the ends of the lower reinforcement member 431 protrude outward through the connecting grooves 422 of the front and rear side frames 420 is that welding must be applied to all connecting parts of the components to ensure the watertightness of the battery case 400, and in addition to the welding itself, a protrusion 434 is required to support the welded joints formed after welding so that they do not flow.

[0110] The length of the front or rear protrusion 434, which is the end portion of both sides of the lower reinforcement member 431 penetrating the front and rear side frames 420 and protruding from the front and rear side frames in the length direction X of the lower reinforcement member, may be in the range of 5 to 10 mm. If the length of the protrusion is less than 5 mm, it is difficult to weld, and if it exceeds 10 mm, it may be difficult to attach the battery case 400 due to interference with surrounding parts.

[0111] In this manner, the protrusion 434 of the lower reinforcement 431 and the connecting grooves 422 of the front and rear side frames 420 are joined to each other by welding, such as arc welding or laser welding, and the formation of the welds ensures watertightness between the ends of the lower reinforcement and the side frames.

[0112] To further ensure watertightness, a coating of a plastic material, such as acrylic resin, epoxy resin, silicone resin, etc., may be applied to the joints, i.e., welds, of the components constituting the case body 402. Alternatively, a metal member may be bonded to cover the welds so as to surround them.

[0113] The upper reinforcing member 432 may have a substantially hat-shaped cross section formed by bending a single plate material having a predetermined width and length multiple times, so that the upper reinforcing member may be formed in a substantially U-shape and may have flanges 433 at both ends in the width direction Y.

[0114] The upper reinforcement 432 is 1 of The upper and lower reinforcements can be joined together by welding, for example by spot welding, laser welding, etc.

[0115] Both ends of the upper stiffener 432 in the length direction X may contact the front and rear side frames 420. Here, the ends of the upper stiffener may be terminated at the front and rear side frames without penetrating the front and rear side frames.

[0116] The flanges 433 of the upper reinforcing member 432 cover the upper side ends of the battery cells 401 housed in the case body 402, and support the battery cells so that the arrangement thereof can be maintained.

[0117] Optionally, the upper reinforcement member 432 may be coupled to a plurality of intermediate cross members 160 arranged at predetermined intervals and extending in the width direction Y of the vehicle to connect both side seals 300 of the vehicle body and a second rear cross member 240 described below. These intermediate cross members and the second rear cross member may support a floor panel.

[0118] At least two reinforcing members 430 may be provided, and thus the number of bottom plates 410 may be one more than the number of reinforcing members. This means that the inside of the battery case 400 can be divided into three or more parts in the width direction Y.

[0119] For example, when the space inside the battery case 400 is divided into thirds, the reinforcing member 430 may be located at a point 1 / 3 of the length of the battery case in the width direction Y from the side frame 420, and a total of two reinforcing members may be provided. When the space inside the battery case is divided into fourths, the reinforcing member may be located at a point 1 / 4 of the length of the battery case in the width direction Y from the side frame, and a total of three reinforcing members may be provided, and it may be selectively determined to place the reinforcing member at the central 1 / 2 point.

[0120] The number of reinforcing members 430 may be determined according to the magnitude of the impact applied from the outside and the number of bottom plates 410 .

[0121] In this manner, in the present invention, reinforcing member 430 consisting of lower reinforcing member 431 and upper reinforcing member 432 having a folded hat-shaped cross section is disposed on case body 402, and the reinforcing member extends along the bottom of the case body and protrudes into the internal space of the case body, so that a folded portion for shock absorption is formed in the case body itself, thereby ensuring high deformation resistance against collision loads.

[0122] After the battery cells 401 are housed in the case body 402 configured in this manner, a cover is coupled to the case body to complete the battery case 400. Then, the battery case can be fixed to, for example, the first front cross member 120, the side seal 300, and the first rear cross member 200 of the vehicle body by bolting or the like using the mounting frame 440, and coupled to the vehicle body.

[0123] In the reinforcing member 430 of the battery case 400, a front end portion of the lower reinforcing member 431, i.e., a front protrusion 434, may be separated from the first connection bracket 153 of the front subframe 150 with a predetermined gap. In addition, among the side frames 420 of the battery case, a front side frame may be separated from the first front cross member 120 with a predetermined gap.

[0124] In the body of an electric vehicle according to one embodiment of the present invention, a joining position P between the first branch portion 112 of the front side member 110 and the first front cross member 120 may overlap an imaginary cross section of a reinforcing member (upper reinforcing member) extending in the longitudinal direction X of the vehicle body. The joining position between the first branch portion of the front side member and the first front cross member may be located at a height corresponding to the upper reinforcing member 432 of the reinforcing member 430 of the battery case.

[0125] In addition, since the first connecting bracket 153 of the front subframe 150 and the end of the first branch portion 112 are connected at the first connecting position P1, the first connecting position can also overlap with an imaginary cross section of the reinforcing member (lower reinforcing member) extending in the longitudinal direction X of the vehicle body. The first connecting position between the first connecting bracket of the front subframe and the end of the first branch portion can be located at a height corresponding to the lower reinforcing member 431 of the reinforcing member 430 of the battery case.

[0126] Here, the cross section of the reinforcing member 430 means a surface of the reinforcing member in the YZ direction (a direction perpendicular to the longitudinal direction X of the vehicle body). Also, the virtual cross section means a mathematical plane with no set thickness, which is not an extension or structure of the reinforcing member that actually exists, but a virtual plane that has the cross-sectional shape of the reinforcing member as it is and extends the cross section of the reinforcing member along the longitudinal direction X of the vehicle body.

[0127] For example, the reinforcing member 430 may be arranged so that its longitudinal axis intersects with the height center line of the connection position P between the first branch portion 112 of the front side member 110 and the first front cross member 120, and the height center line of the first connection position P1 between the first connecting bracket 153 of the front subframe 150 and the end of the first branch portion 112, but this is not necessarily limited to this.

[0128] At this time, the first connection position P1 is located below the connection position P between the first branch portion and the first front cross member.

[0129] In the body of an electric vehicle according to one embodiment of the present invention, the connection position P where the first branch portion 112 of the front side member 110 meets the first front cross member 120, and the first connection position P1 where the first branch portion meets the first connecting bracket 153 of the front subframe 150 are disposed at the end of the first branch portion, thereby unifying the load path that transmits the collision load of the vehicle body.

[0130] Due to such alignment of the reinforcing member 430 and the coupling positions P and P1, the reinforcing member of the battery case 400 can play a role in supporting the collision load transmitted from the front side member 110.

[0131] In addition, in the body of an electric vehicle according to one embodiment of the present invention, the connection position Q between the second branch portion 113 of the front side member 110 and the first front cross member 120 can overlap a cross section of the side frame 420 extending along the longitudinal direction X of the body with a virtual cross section extending in the longitudinal direction X of the body.

[0132] Here, the cross section of the side frame 420 refers to a surface of the side frame in the YZ direction (a direction perpendicular to the longitudinal direction X of the vehicle body). Also, the virtual cross section refers to a mathematical plane with no set thickness, which is a virtual plane that has the cross-sectional shape of the side frame as it is and extends along the longitudinal direction X of the vehicle body, rather than an extension or structure of the side frame that actually exists.

[0133] Due to such an alignment of the side frame 420 and the coupling position Q, the side frame of the battery case 400 can also play a role in supporting the collision load transmitted from the front side member 110.

[0134] Therefore, in the body of the electric vehicle according to the embodiment of the present invention, the battery case 400 including the reinforcing member 430 and the side frame 420 is fixed to the body, so that the rigidity and crash resistance of the body can be improved.

[0135] In addition, in the body of an electric vehicle according to one embodiment of the present invention, the bottom of the case body 402 is divided into a plurality of bottom plates 410, and a lower reinforcement member 431 with an open cross section is arranged between the bottom plates. The lower reinforcement member extends along the bottom of the case body, penetrating the side frame 420 and at the same time opening to the outside (i.e., downward) of the case body so that the hollow portion of the lower reinforcement member is exposed to the outside of the battery case 400, which has the advantage that the hollow portion of the lower reinforcement member can be used as space for other parts of the vehicle.

[0136] FIG. 8 is a diagram corresponding to FIG. 4 for explaining the path of the collision load, and FIG. 9 is a diagram corresponding to FIG. 5 for explaining the path of the collision load.

[0137] In the electric vehicle body according to an embodiment of the present invention, the front side member 110 can directly absorb the collision energy entering the front part 111 from the front bumper beam 60 .

[0138] Next, the front side member 110 has a first branch portion 112 connected to the first front cross member 120 and a second branch portion 113 connected to the side seal 300, so that the excess collision load that enters the front portion 111 can be distributed to the first front cross member and the side seal via the first branch portion and the second branch portion and transmitted to the vehicle body.

[0139] In other words, a collision load that exceeds the absorption capacity of the front side member 110 can be transferred to the member surrounding the battery space 40 below the floor panel while being connected to the front side member.

[0140] Since deformation needs to be minimized within the battery space 40, it is necessary to prevent the penetration of the collision load into the load support member. While the side seal 300 can function as a load support member in a frontal collision, the first front cross member 120 does not have a load support member.

[0141] In the body of an electric vehicle according to one embodiment of the present invention, a reinforcing member 430 of a battery case 400 is arranged in correspondence with a point where a collision load is transmitted in the first front cross member 120, thereby preventing deformation from occurring within the battery space 40.

[0142] More specifically, when a collision load exceeding the absorption capacity of the front side members 110 is transmitted to the first front cross member 120, the first front cross member is deformed and comes into contact with the front side frame 420 of the battery case 400 separated by a predetermined gap. The front side frame of the battery case can then be supported by the upper reinforcing member 432 of the reinforcing member 430 therein, thereby preventing the collision load from penetrating into the battery space 40.

[0143] Furthermore, in the event of a frontal collision, the front subframe 150 can further absorb the collision energy.

[0144] Next, the front subframe 150 is connected to the end of the first branch portion 112 via the first connecting bracket 153, so that a collision load that exceeds the absorption capacity of the front subframe can be transmitted to the first front cross member 120 and the vehicle body via the first branch portion.

[0145] When a collision load exceeding the absorption capacity of the front subframe 150 is transmitted to the first front cross member 120, the first front cross member is deformed and the first connecting bracket 153 comes into contact with an end of the lower reinforcement member 431 of the battery case 400, i.e., the front protrusion 434, which is spaced apart from the end by a predetermined gap. Then, the first connecting bracket and the front subframe can be supported by the lower reinforcement member of the reinforcement member 430 protruding from the side frame 420 on the front side of the battery case, thereby preventing the collision load from penetrating into the battery space 40.

[0146] That is, by forming one of the load paths coming from the front with the reinforcing member 430 of the battery case 400, the reinforcing member of the battery case can directly function as a load supporting member.

[0147] As described above, the body of an electric vehicle according to one embodiment of the present invention can not only protect the battery space 40 but also support the load, so that the front side member 110, the front subframe 150, the first front cross member 120 and the battery case 400 can be organically connected to each other to form a load path.

[0148] In this manner, the collision load generated at the front of the vehicle can be distributed and transmitted to the rear of the vehicle body, so that the collision performance of an electric vehicle to which a body according to an embodiment of the present invention is applied can be improved.

[0149] Such electric vehicles have the advantage that they can ensure crashworthiness and safety despite the increased weight of the vehicle and reduced space in the body due to the incorporation of batteries, which can lead to improved marketability of the vehicle.

[0150] 2 to 5 and 10, the body of an electric vehicle according to an embodiment of the present invention may include a rear side member 210, a first rear cross member 220, and a rear sub-frame 250.

[0151] The rear side members 210 may be provided in a pair, and may be disposed on both the left and right sides in the width direction Y of the vehicle body while extending along the length direction X of the vehicle body.

[0152] For example, the rear side member 210 may extend parallel to a center line O extending in the longitudinal direction X of the vehicle body for a certain length from the rear, and the two rear side members may be disposed so as to become farther apart from each other toward the front.

[0153] The rear side member 210 can effectively transmit a collision load entering from the rear bumper beam 70 to the vehicle body via the side seal 300 or the first rear cross member 220, etc.

[0154] For convenience, only one of the two rear side members 210 will be described below. The other of the two rear side members can be included and arranged symmetrically to the configuration of the rear side member described.

[0155] One end, i.e., the rear end, of the rear side member 210 may be connected to the rear bumper beam 70 , and the other end, i.e., the front end, may be connected to one side surface at the rear of the side seal 300 .

[0156] Such a rear side member 210 may be formed of a tubular member having a cross-sectional shape such as a rectangle, but is not necessarily limited to this, and may be formed of a member made of a single plate material having a cross-sectional shape that is bent to have an open cross-section or a curved cross-sectional shape, or a member made of two or more plate materials joined together.

[0157] The rear side member 210 may be made of a metal material such as steel, and may be shaped by press forming, stamping, bending, roll forming, or a combination thereof.

[0158] More specifically, the rear side member 210 can be made of a plate material such as 980 XF steel having a thickness of about 1.3 mm to 1.5 mm produced by the present applicant.

[0159] The front side of the rear side member 210 can be bent downward, thereby forming an inclined portion 214. An end of the inclined portion can come into surface contact with the inner side surface of the side seal 300.

[0160] As a result, a front end of the rear side member 210 can be fixed, for example by welding, to an inner side surface of a side seal 300 of the vehicle body, one side surface of which extends in the longitudinal direction X of the vehicle.

[0161] One side surface of the front end portion of the rear side member 210 is fixed to the side seal 300, so that the rear side member can transmit a collision load to the side seal.

[0162] The configuration and arrangement of the rear side member 210 are not limited to the above example.

[0163] The first rear cross member 220 may connect the rear side members 210. In other words, the first rear cross member may be connected to the inner side surfaces of the rear side members. In addition, a rear subframe 250, which will be described later, may be attached to the first rear cross member.

[0164] The body of the electric vehicle according to an embodiment of the present invention may further include a second rear cross member 240 extending in the width direction Y of the vehicle, connecting both side seals 300 and coupled to a front end of the rear side member 210.

[0165] The second rear cross member 240 is located forward of the first rear cross member 220, and can be joined to the front end of the rear side member 210. The end of the rear side member is fixed to the rear surface of the second rear cross member, for example, by welding, and can contact the side seal 300 and the second rear cross member simultaneously.

[0166] The front end of the rear side member 210 is in contact with the rear surface of the second rear cross member 240, so that the rear side member can reliably transmit the collision load to the second rear cross member.

[0167] In addition, the second rear cross member 210 may be located at an upper portion of the battery case 400 and may be coupled to an upper reinforcing member 432 of the reinforcing member 430. The second rear cross member may support a floor panel.

[0168] The first and second rear cross members 220, 240 may be provided, for example, as tubular members having a hollow interior and a cross-sectional shape that is a polygon having a square or more sides, but are not necessarily limited to this, and may be formed of a member made of a single plate material that is bent to have an open cross-section or has a curved cross-sectional shape, or a member made of two or more plate materials joined together.

[0169] After the first and second rear cross members 220, 240 are joined to the rear side members 210 on both sides, the vehicle body can be made lighter while maintaining its torsional and bending rigidity.

[0170] The first and second rear cross members 220, 240 may be made of ultra-high strength steel, for example, of 980 MPa class or higher, thereby achieving an optimal combination for adding rigidity to the rear cross members while reducing their weight.

[0171] More specifically, the first rear cross member 220 may be made of a plate material such as 1180 TRIP (Transformation Induced Plasticity) steel with a thickness of about 1.1 mm to 1.3 mm produced by the present applicant. Here, 1180 TRIP steel is a type of steel that has an elongation rate of 45% or more while ensuring a tensile strength of 1180 MPa or more and a yield strength of 850 MPa or more.

[0172] The second rear cross member 240 may be made of a plate material such as 1470 MART steel having a thickness of about 1.1 mm to 1.3 mm produced by the present applicant.

[0173] In addition, the second rear cross member 240 can have even higher strength than the first rear cross member 220.

[0174] The side seals 300 may be formed and disposed at the lower portions of both the left and right sides of the vehicle body to extend along the longitudinal direction X of the vehicle, and may be coupled to ends of the second rear cross member 240.

[0175] The side seal 300 serves as an important vehicle body structure in response to front, rear and side collisions of the vehicle.

[0176] The rear subframe 250 has a substantially rectangular frame shape in which two horizontal members 251 formed to extend in the width direction Y of the vehicle are connected at both ends to two vertical members 252 formed to extend in the length direction X of the vehicle.

[0177] A mounting bracket for fixing a spring link of the suspension may be provided on the bottom surface of the rear subframe 250, and a mounting bracket for a mounting bush for mounting the powertrain may be provided.

[0178] Meanwhile, a second connection bracket 223 extending in the longitudinal direction X of the vehicle may be provided on the first rear cross member 220. The second connection bracket may have a bolt hole formed therein, and may be connected to a front cross member 251 of the rear subframe 250 by bolting. The second connection bracket and the front cross member define a fourth connection position P4.

[0179] Furthermore, the vertical member 252 of the rear subframe 250 may be connected to the center of the rear side member 250 by bolting at a rear end portion. Here, the connection point between the rear end portion and the rear side member is defined as a fifth connection position P5.

[0180] In this manner, the rear subframe 250 is connected to the rear side member 250 at multiple connection positions P4, P5, i.e., four connection points, thereby increasing the rigidity of the connection portion and allowing the rear subframe 250 to be stably attached to and supported by the rear side member and the first rear cross member 220.

[0181] In the electric vehicle body according to an embodiment of the present invention, the installation position of the second connection bracket 223 on the first rear cross member 220 constituting the fourth coupling position P4 may be determined according to the number of divisions of the space inside the battery case 400.

[0182] For example, when the space within the battery case is divided into thirds, the fourth coupling position P4 on the second connecting bracket 223 of the first rear cross member 220 may be aligned to correspond to a 1 / 3 point in the length in the width direction Y from the side frame 420 of the battery case 400. When the space within the battery case is divided into fourths, the fourth coupling position on the second connecting bracket of the first rear cross member may be aligned to correspond to a 1 / 4 point in the length in the width direction Y from the side frame of the battery case.

[0183] In addition, in the reinforcing member 430 of the battery case 400, the rear end of the lower reinforcing member 431, i.e., the rear protrusion 434, may be separated at a predetermined gap from the second connection bracket 223 of the first rear cross member 220 and the front horizontal member 251 of the rear subframe 250. In addition, of the side frames 420 of the battery case, the rear side frame may be separated at a predetermined gap from the first rear cross member.

[0184] In the electric vehicle body according to an embodiment of the present invention, the fourth connection position P4 between the second connection bracket 223 of the first rear cross member 220 and the front cross member 251 of the rear subframe 250 can be overlapped with an imaginary cross section of the reinforcing member (upper reinforcing member) extending in the longitudinal direction X of the vehicle body. 2 A fourth coupling position between the connection bracket and the front cross member of the rear subframe may be located at a height corresponding to the upper reinforcement member 432 of the reinforcement member 430 of the battery case.

[0185] For example, the reinforcing member 430 may be positioned so that its longitudinal axis intersects with the heightwise centerline of the fourth connection position P4 between the second connecting bracket 223 of the first rear cross member 220 and the front cross member 251 of the rear subframe 250, but this is not necessarily limited to this.

[0186] Due to the alignment of the reinforcing member 430 and the coupling positions P4 and P5, the reinforcing member of the battery case 400 can play a role in supporting the collision load transmitted from the rear sub-frame 250.

[0187] Therefore, in the body of the electric vehicle according to the embodiment of the present invention, the battery case 400 having the reinforcing member 430 is fixed to the body, thereby improving the rigidity and crash resistance of the body.

[0188] 8 to 10, in the body of the electric vehicle according to one embodiment of the present invention, the rear side member 210 can directly absorb the collision energy entering from the rear bumper beam 70. As shown in FIG.

[0189] Next, the rear side member 210 has its side connected to the side seal 300 and its end connected to the second rear cross member 240, so that the excess collision load that enters the rear side member can be distributed to the side seal and the second rear cross member and transmitted to the vehicle body.

[0190] In other words, a collision load that exceeds the absorption capacity of the rear side member 210 can be transferred to a portion of the member surrounding the battery space 40 below the floor panel while being connected to the rear side member.

[0191] It is necessary to prevent the penetration of the collision load into the load support member because deformation needs to be minimized within the battery space 40. In a rear-end collision, the side seal 300 can function as a load support member, whereas the first rear cross member 220 does not have a load support member.

[0192] In the body of an electric vehicle according to one embodiment of the present invention, the reinforcing member 430 of the battery case 400 is arranged to correspond to the point where the collision load is transmitted in the first rear cross member 220, thereby preventing deformation from occurring within the battery space 40.

[0193] More specifically, the rear subframe 250 is connected to the rear side member 210 at the rear end of the vertical member 252, i.e., at the fifth connection position P5, so that the rear subframe can transmit a portion of the collision energy in the event of a rear-end collision.

[0194] Since the rear subframe 250 is connected to the first rear cross member 220 via the second connecting bracket 223, a portion of the collision load that exceeds the absorption capacity of the rear side member 210 can be transmitted to the first rear cross member 220 and the vehicle body via the rear subframe.

[0195] When a collision load is transmitted to the first rear cross member 220 by the rear subframe 250, the first rear cross member is deformed, and the front cross member 251 of the rear subframe comes into contact with the end of the rear side frame 420 or the lower reinforcement member 431 of the battery case 400, i.e., the rear protrusion 434, which is spaced apart from the rear side frame 420 by a predetermined gap. Then, the rear side frame of the battery case can be supported by the upper reinforcement member 432 of the reinforcement member 430 located therein, thereby preventing the collision load from penetrating into the battery space 40.

[0196] Alternatively, the rear subframe 250 can be supported by the lower reinforcement 431 of the reinforcing member 430 protruding from the rear side frame 420 of the battery case 400, thereby preventing the collision load from penetrating into the battery space 40.

[0197] That is, by configuring one of the load paths coming from the rear with the reinforcing member 430 of the battery case 400, the reinforcing member of the battery case can directly function as a load supporting member.

[0198] However, unlike the front side member 110 at the front, the rear side member 210 transmits a part of the collision load to the reinforcing member 430 of the battery case 400 via the rear subframe 250.

[0199] As described above, the body of the electric vehicle according to one embodiment of the present invention can form a load path by organically connecting the rear side member 210, the rear subframe 250, the first rear cross member 220 and the battery case 400 to each other so as to not only protect the battery space 40 but also support the load.

[0200] In this manner, the collision load generated at the rear of the vehicle can be distributed and transmitted to the front of the vehicle body, so that the collision performance of an electric vehicle to which a body according to an embodiment of the present invention is applied can be improved.

[0201] Such an electric vehicle has an advantage that it is possible to ensure collision performance and safety even though the weight of the vehicle increases and the space in the body is reduced due to the installation of a battery, which can lead to improved marketability of the vehicle.

[0202] As described above, according to the present invention, the reinforcing member of the battery case is configured to act as a path for the collision load and as a direct load supporting member, thereby achieving the effect of distributing the load across the vehicle body in the event of a frontal or rearward collision, efficiently suppressing the penetration and deformation of the collision load, and reducing weight.

[0203] The above description is merely an illustrative example of the technical concept of the present invention, and various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains without departing from the essential characteristics of the present invention.

[0204] Therefore, the embodiments disclosed in the present invention are for the purpose of illustrating, rather than limiting, the technical idea of ​​the present invention, and such embodiments do not limit the scope of the technical idea of ​​the present invention. The scope of protection of the present invention should be interpreted according to the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0205] 10 Non-penetration area 20, 30 Energy absorption area 40 Battery Space 60 Front bumper beam 70 Rear bumper beam 110 Front side member 111 Front section 112 First Branch 113 Second Branch 120 First front cross member 130 Dash Panel 140 Second front cross member 150 Front subframe 151, 251 Lateral members 152, 252 Vertical members 153 First connecting bracket 160 Intermediate cross member 210 Rear side member 220 First rear cross member 223 Second connecting bracket 240 Second rear cross member 250 rear subframe 300 Side seal 400 Battery Case 401 Battery Cell 402 Case body 410 Bottom plate 420 Side Frame 430 Reinforcement members 431 Lower Reinforcement 432 Upper Reinforcement 434 Protrusion 440 mounting frame

Claims

1. a front side member having one side connected to the front bumper beam and the other side branched to form a first branch portion and a second branch portion; a first front cross member extending along a width direction of the vehicle body and coupled to the first branch portion and the second branch portion; a side seal extending along a longitudinal direction of the vehicle body and coupled to the second branch portion; A front subframe coupled to the front side member; and a battery case including a reinforcing member extending along a longitudinal direction of the vehicle body and coupled to the first front cross member and the side seal; An electric vehicle body, wherein a joining position where the first branch portion and the first front cross member are joined and a first joining position where the first branch portion and the front subframe are joined are such that a cross section of the reinforcing member overlaps a virtual cross section extending in the longitudinal direction of the vehicle body.

2. The front side member includes a front portion that extends linearly and has one side connected to the front bumper beam, The electric vehicle body according to claim 1 , wherein the first branch portion and the second branch portion branch off from another side of the front portion.

3. The electric vehicle body according to claim 2 , wherein the first branch portion and the second branch portion are formed of a material having a higher strength than the front portion.

4. The electric vehicle body according to claim 2 , wherein the first branch portion and the second branch portion are formed to have a thickness greater than a thickness of the front portion.

5. The electric vehicle body according to claim 1 , further comprising a second front cross member extending along a width direction of the vehicle body and coupled to the front side member.

6. The electric vehicle body according to claim 5 , wherein the second front cross member is located forward and above the first front cross member and is coupled to the first branch portion.

7. 7. The electric vehicle body according to claim 6, wherein the first front cross member is formed to have a thickness greater than a thickness of the second front cross member.

8. 2. The electric vehicle body according to claim 1, wherein the front side members are disposed inclined at a predetermined angle with respect to a center line extending in a longitudinal direction of the vehicle body.

9. The front side members are disposed on both the left and right sides in a width direction of the vehicle body, 9. The electric vehicle body according to claim 8, wherein the two front side members are disposed so as to approach each other toward the rear of the vehicle body.

10. The first branch portion is bent downward to form a curved portion, The electric vehicle body according to claim 1 , wherein one side of the end of the curved portion is fixed in contact with a front surface of the first front cross member.

11. a first connection bracket extending in a longitudinal direction of the vehicle body is provided at a rear end of the front subframe, The electric vehicle carbody of claim 10 , wherein the first connecting bracket and the first branch portion define the first coupling location.

12. The electric vehicle body according to claim 11 , wherein the first connecting bracket is coupled to a bottom surface at an end of the curved portion.

13. The electric vehicle body according to claim 12 , wherein the first connection position is located below a connection position between the first branch portion and the first front cross member.

14. a rear end portion of the front subframe is coupled to the front side member to define a second coupling position; The electric vehicle body according to claim 11 , wherein the second coupling position is located at the front side member so as to correspond to a point where the first branch portion and the second branch portion branch off from each other.

15. The battery case includes a case body that houses a battery cell, The case body includes: Multiple bottom plates; A side frame surrounding the plurality of bottom plates; and 12. The electric vehicle body according to claim 11, further comprising at least two of the reinforcing members disposed between the bottom plates and coupled to the side frames at both longitudinal ends thereof.

16. The reinforcing member is Lower reinforcement, and an upper reinforcement member coupled to an upper portion of the lower reinforcement member; A coupling groove is formed at a coupling portion of the side frame that meets an end of the lower reinforcement member, the coupling groove being recessed in a height direction from a bottom surface of the side frame and penetrating in a width direction of the side frame; The electric vehicle body according to claim 15 , wherein an end portion of the lower reinforcement member penetrates the side frame through the coupling groove to form a protrusion protruding from the side frame.

17. The electric vehicle body according to claim 16 , wherein the front protrusion of the lower reinforcement member is spaced apart from the first connection bracket of the front subframe.

18. 17. The electric vehicle body according to claim 16, wherein the first coupling location is located at a height corresponding to the lower stiffener.

19. 17. The electric vehicle body according to claim 16, wherein a joining position between the first branch portion and the first front cross member is located at a height corresponding to the upper reinforcement member.

20. The electric vehicle body of claim 15, wherein the connection position between the second branch portion and the first front cross member is such that a cross section of the side frame extending along the longitudinal direction of the vehicle body overlaps with an imaginary cross section extending in the longitudinal direction of the vehicle body.

21. 2. The body of an electric vehicle as described in claim 1, wherein the longitudinal axis of the reinforcing member intersects with the height centerline of the connection position between the first branch portion and the first front cross member, and the height centerline of the first connection position.

22. The lower reinforcement member has an inverted U-shaped cross section, The upper stiffener has a U-shaped cross section, The body of an electric vehicle according to claim 16 , wherein the hollow portion of the lower reinforcement member is arranged so as to be exposed to the outside of the battery case.

23. The case body further includes a mounting frame for fixing the battery case to a vehicle body, The electric vehicle body according to claim 16, wherein the mounting frame is attached to the side frame away from a portion where the coupling groove is formed.

24. The end of the lower reinforcement member is sandwiched in the coupling groove to form a shape that matches the shape of the lower reinforcement member. The electric vehicle body according to claim 16, wherein a weld is formed between the protrusion of the lower reinforcement member and the coupling groove.

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