Electric car body

Abstract

To provide a body of an electric vehicle capable of minimizing penetration of a crash induced load into a passenger space and battery space at a time of a collision from forward or backward.SOLUTION: A body of an electric vehicle includes front side members each of which has one side coupled to a front bumper beam and has the other side bifurcated into a first branch part and second branch part, a first front cross member coupled to the first branch parts and second branch parts, side seals coupled to the respective second branch parts, a front sub frame coupled to the front side members, and a reinforcement member extending in a length direction of the body. The body further includes a battery case coupled to the side seals and first front cross member. A coupled position between the first branch part and first front cross member and a first coupled position between the first branch part and front sub frame are superposed on a virtual section corresponding to the cross-section of the reinforcing member extending in the lengthwise direction of the vehicle body.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] In the event of a collision, a vehicle must absorb as much collision energy as possible at the front or rear, minimizing the transfer of load to the passenger compartment or, in the case of an electric vehicle, the battery compartment.

[0003] For this reason, the anti-intrusion zone of the vehicle body, which must suppress the penetration of collision loads and prevent deformation, is 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 body. [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 penetration of collision load 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 one side connected to a 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 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 a virtual cross section of the reinforcing member 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 connected to a rear bumper beam on one side; a first rear cross member extending along the width direction of the body and connected to the rear side member; a side seal extending along the length direction of the 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 battery case including a reinforcing member extending along the length direction of the body and connected to the first rear cross member and the side seal, wherein a fourth connection position where the rear subframe and the first rear cross member are connected may be such that a cross section of the reinforcing member overlaps with an imaginary cross section extending in the length direction of the body. [Effects of the Invention]

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

[0009] [Figure 1]1 is an exploded perspective view showing a car body of an electric vehicle according to an embodiment of the present invention; [Figure 2] 1 is a bottom view of a car body of an electric vehicle according to an embodiment of the present invention, showing a state before a battery case and a subframe are attached. [Figure 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 of a car body of an electric vehicle according to an embodiment of the present invention, showing a state in which a battery case and a subframe are attached; [Figure 5] FIG. 5 is a cross-sectional view taken along line AA in FIG. 4, showing the battery case and 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 the path of a collision load. [Figure 9] FIG. 6 is a diagram corresponding to FIG. 5 for explaining the path of a collision load. [Figure 10] 6 is an enlarged view of a part of FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

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

[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-penetrated area, while the non-penetrated area must be designed to be relatively strong to prevent deformation and protect the passenger space and battery space.

[0012] To achieve this, the most efficient way is to increase the number of load support members to distribute the load, but in the case of ordinary electric vehicles, the non-permeable area is the space where the battery should 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 the collision load and suppress penetration, as mentioned above, it is necessary to use very strong and thick materials for these components, which causes the weight of the vehicle body to increase.

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

[0015] The present invention will now be described in detail with reference to the accompanying drawings, in which like reference numerals are used to designate like elements in the drawings, and it should be noted that like elements will have the same reference numerals as far as possible even when they are displayed in different drawings.

[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 relative to the vehicle or vehicle body.

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

[0018] FIG. 1 is an exploded perspective view showing the body of an electric vehicle according to one embodiment of the present invention, FIG. 2 is a bottom view showing the body of an electric vehicle according to one embodiment of the present invention, FIG. 3 is a side view showing the state before the battery case and subframe are attached, FIG. 4 is a bottom view showing the body of an electric vehicle 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 skeletal structure of the vehicle body can be composed of side members that extend in the longitudinal 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 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 referred to as front side members 110, rear side members 210, etc. depending on the position where the cross members are connected or their position relative to the floor panel (not shown). Meanwhile, side seals 300 that protect the passenger space in the event of a side collision and define the outline of the side may be provided on the sides 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 where passengers board can be provided above the battery space 40.

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

[0024] As shown in more detail in Figures 2 to 5, the body of an electric vehicle according to one 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 are provided in pairs and extend along the length direction X of the vehicle body, and can be disposed on both the left and right sides in the width direction Y 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 as they extend rearward.

[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 way, 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 so that the center point of one end connected to the front bumper beam 60, i.e., the front end, is located between 20% and 30% from the outside to the inside 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% of the vehicle's width from the outside to the inside, 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 width on the driver's or passenger's side collides with an obstacle at a speed of 64 km / h).

[0030] The front side members 110 can effectively transmit the collision load that enters the front side members 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 members can play a role in eliciting the behavior of the vehicle in the width direction Y.

[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 so that the configuration of the described front side member is symmetrical.

[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 from the front portion.

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

[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 curved cross-sectional shape or a member made of two or more plates joined together, which is bent to have an open cross-section.

[0035] The front part 111 may be made of a metal material such as steel, and may be formed 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 with a thickness of approximately 1.5 mm to 1.7 mm, manufactured 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., the front end portion, may be connected to the other end of the front portion.

[0038] The 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 that is bent to have an open cross-section or has 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 the front surface of a first front cross member 120 and the front surface of a dash panel 130 extending in the width direction Y of the vehicle body.

[0040] In addition, 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 contacts the front surface of the dash panel 130, and one side of the end of the curved portion may be in surface contact with the front surface of the first front cross member 120 and fixed thereto by, for example, welding.

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

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

[0043] The first branch portion 112 may be molded integrally and continuously with the front portion 111 and extend linearly from the front portion. While 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] When 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 113 can 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 to the front surface of the side seal 300 and the front surface of the first front cross member 120, for example by welding, so that it can 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 and underside of the first front cross member 120, and the second branch portion can reliably transmit the collision load to at least the first front cross member.

[0050] Furthermore, the 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 one embodiment of the present invention, the front side member 110 is not limited to the above-described configuration.

[0052] For example, the second branch portion 113 may be molded continuously and integrally with the front portion 111 and extend linearly from the front portion, and 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 way, 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 separately, and then connected and fixed to one another by, for example, welding, to manufacture the front side member 110. In this case, there is an advantage in that the degree of freedom in assembling, dimensions, materials, etc. can be expanded when 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 or roll forming.

[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 approximately 1.7 mm to 2.0 mm, which is manufactured by the present applicant. Here, 1470 HPF steel is a type of steel that has a tensile strength of 1,470 MPa or more and 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 way, by combining the strengths of the plate materials that form the front side member 110, the impact absorption capacity 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 thicker than the front portion 111. In this way, the branch portions that 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 can also extend 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 the 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 can be connected 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 polygonal cross-sectional shape of at least a square, but are not necessarily limited to this. They 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 by joining two or more plates.

[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, which provides an optimal combination for adding rigidity to the front cross members while reducing their weight.

[0065] More specifically, the first and second front cross members 120 and 140 may be made of a plate material such as 1470 MART (Martensitic) steel with a thickness of approximately 1.1 mm to 1.5 mm, manufactured 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 arranged to extend along the longitudinal direction X of the vehicle at the lower portions of both the left and right sides of the vehicle body.

[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 attached to 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 formed by press forming, bending, roll forming, or a combination thereof.

[0070] The crashworthiness of the side seal 300 can be ensured by adjusting the material of the plate forming the side seal and the strength or thickness of this material. For example, by using ultra-high strength steel of 980 MPa or higher, an optimal combination can be achieved to reduce the weight of the side seal.

[0071] More specifically, the side seal 300 can be made of a plate material such as 1470 MART steel having a thickness of approximately 1.1 mm to 1.3 mm, which is 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, since buckling is likely to occur under various collision conditions if the inside of the side seal becomes empty, various types of reinforcing means can be supplemented inside the side seal.

[0073] The front subframe 150 has a substantially 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 both ends thereof may be provided with mounting brackets 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 the rear end of the vertical member 152. A bolt hole is formed in the first connecting bracket, and the first connecting bracket may be connected to an end of the 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 its front end and rear end, respectively. Here, the connection point with the rear end is referred to as a second connection position P2, and the connection point with the front end is referred to as 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 enabling 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 the connection between a first front cross member and a battery case in the 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 press processing.

[0085] The case body 402 may be directly exposed to the outside and is highly susceptible to breakage and damage 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 moderate 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 joining these components.

[0087] For convenience, the battery case 400 will be described below, focusing on the case main body 402.

[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, and can function as a member that supports the battery cells 401 in the case body 402.

[0090] The height 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 plurality of bottom plates 410, and both ends of each side frame are cut at a predetermined angle (e.g., about 45 degrees), and after being joined to the corresponding other side frames at their respective ends, they can be joined by welding, such as arc welding or laser welding.

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

[0093] In this way, the side frame 420 forms a "ring" (a form that does not break and is strongly connected) that separates the non-penetrating 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 in a shape corresponding to the cross-sectional shape of the reinforcing member 430, so that when the end of the reinforcing member is sandwiched in the coupling groove, the shapes of the reinforcing member and the reinforcing member can be matched.

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

[0097] The case body 402 of the battery case 400 may have a mounting frame 440, which is required to fix the battery case to the vehicle body, coupled to a surface constituting the 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 at positions other than the positions where the coupling grooves 422 are formed.

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

[0101] The reinforcing member 430 may include a lower reinforcing member 431 and an upper reinforcing member 432 connected 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 plate of metal, such as steel, etc. The stiffeners may be shaped by bending or roll forming, for example.

[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 materials with a tensile strength of approximately 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, which is produced by the present applicant.

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

[0106] The lower reinforcement member 431 may be disposed between the 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 member 431 in the length direction X can meet with the front and rear side frames 420 and be coupled to the front and rear side frames. As described above, coupling grooves 422 are formed at the coupling portions of the front and rear side frames that meet with the ends of the lower reinforcement member, and the ends of the lower reinforcement member can be sandwiched in the coupling grooves to mate with each other.

[0108] Here, the front and rear side frames 420 may be seated on the flanges 433 of the lower reinforcement member 431, while the ends of the lower reinforcement member 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, protrusions 434 are required to support the welded joints formed after welding so that they do not flow.

[0110] The length of the front or rear protrusions 434, which are formed by the ends 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 longitudinal 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, welding may be difficult, and if it exceeds 10 mm, interference with surrounding components may occur, making it difficult to install the battery case 400.

[0111] In this way, 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 a weld ensures watertightness between the end 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, or silicone resin 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 surround and cover the welds.

[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, thereby forming the upper reinforcing member in a substantially U-shape and providing 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 to each other by welding, for example, spot welding, laser welding, etc.

[0115] Both ends of the upper reinforcement member 432 in the length direction X may contact the front and rear side frames 420. Here, the ends of the upper reinforcement member may terminate at the front and rear side frames without passing through the front and rear side frames.

[0116] The flanges 433 of the upper reinforcing member 432 cover the upper side edges 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, which are spaced apart at predetermined intervals and extend in the width direction Y of the vehicle to connect the side seals 300 on both sides of the vehicle body, and a second rear cross member 240, which will be described later. These intermediate cross members and 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 interior of the battery case 400 can be divided into three or more sections 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 way along the width direction Y of the battery case from the side frame 420, so that a total of two reinforcing members are 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 way along the width direction Y of the battery case from the side frame, so that a total of three reinforcing members are provided, and the placement of the reinforcing member at the central 1 / 2 point may be selectively determined.

[0120] The number of reinforcing members 430 may be determined depending on the magnitude of the external impact and the number of bottom plates 410 .

[0121] In this way, in the present invention, a reinforcing member 430 consisting of a lower reinforcing member 431 and an upper reinforcing member 432 with a folded hat-shaped cross section is arranged on the 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, ensuring high deformation resistance against collision loads.

[0122] After the battery cells 401 are housed in the case body 402 configured as described above, the cover is coupled to the case body to complete the battery case 400. The battery case can then be coupled to the vehicle body by being 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 using the mounting frame 440 by bolting or the like.

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

[0124] In the body of an electric vehicle according to one embodiment of the present invention, a connection 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 the reinforcing member (upper reinforcing member) extending in the longitudinal direction X of the vehicle body. The connection 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] Furthermore, because 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 refers to a plane 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 refers to a mathematical plane with no set thickness, which is not an extension or structure of the reinforcing member that actually exists, but rather a virtual plane that has the cross-sectional shape of the reinforcing member as it is and is formed by extending the cross section of the reinforcing member along the longitudinal direction X of the vehicle body.

[0127] For example, the longitudinal axis of the reinforcing member 430, 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 may be arranged to intersect, 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 located at the end of the first branch portion, thereby unifying the load path that transmits the collision load of the body.

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

[0131] Furthermore, 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 plane 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 does not refer to an extension or structure of the side frame that actually exists, but rather has the cross-sectional shape of the side frame as it is and is an imaginary plane extending along the longitudinal direction X of the vehicle body.

[0133] Due to such 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 one embodiment of the present invention, the battery case 400 including the reinforcing member 430 and the side frame 420 is fixed to the body, thereby improving the rigidity and crash resistance of the body.

[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, penetrates the side frame 420, and at the same time opens 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 one 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 has entered 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 transmitted 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 penetration of the collision load into the load-bearing member. While the side seal 300 can function as a load-bearing member in a frontal collision, the first front cross member 120 does not have a load-bearing member.

[0141] In the body of an electric vehicle according to one embodiment of the present invention, a reinforcing member 430 of the battery case 400 is arranged in correspondence with the point where the 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, which is spaced apart from the first front cross member 120 by a predetermined gap. The front side frame of the battery case is then 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 the end of the lower reinforcing member 431 of the battery case 400, i.e., the front protrusion 434, which is spaced apart from the first connecting bracket 153 by a predetermined gap. The first connecting bracket and the front subframe are then supported by the lower reinforcing member of the reinforcing 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 configuring 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 the electric vehicle according to one embodiment of the present invention can not only protect the battery space 40 but also support the load, and the front side members 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 way, the collision load generated at the front of the vehicle can be dispersed and transmitted to the rear of the vehicle body, so that the collision performance of an electric vehicle to which a vehicle body according to an embodiment of the present invention is applied can be improved.

[0149] Such electric vehicles have the advantage of being able to ensure crashworthiness and safety despite the increased weight and reduced vehicle body space due to the inclusion 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 are provided in pairs and may be disposed on both the left and right sides of the vehicle body in the width direction Y 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 arranged so that they become farther apart from each other as they move forward.

[0153] The rear side member 210 can effectively transmit the collision load that enters 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 so that the configuration of the rear side member described is symmetrical.

[0155] One end of the rear side member 210, i.e., the rear end, 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 of 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 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.

[0157] The rear side member 210 may be made of a metal material such as steel, and may be formed 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 approximately 1.3 mm to 1.5 mm, which is produced by the present applicant.

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

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

[0161] One side surface of the front end 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 (described later) may be attached to the first rear cross member.

[0164] The body of the electric vehicle according to one 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 connecting to the 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 come into contact with 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 on the upper portion of the battery case 400 and may be coupled to the 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 polygonal cross-sectional shape of at least a square, but are not necessarily limited to this. They 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 by joining two or more plates.

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

[0170] The first and second rear cross members 220, 240 may be made of ultra-high strength steel, for example, 980 MPa or higher, to achieve an optimum combination of adding rigidity to the rear cross members and 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 approximately 1.1 mm to 1.3 mm, manufactured by the present applicant. Here, 1180 TRIP steel is a type of steel that guarantees a tensile strength of 1180 MPa or more and a yield strength of 850 MPa or more, while also improving elongation to 45% or more.

[0172] The second rear cross member 240 can be made of a plate material such as 1470 MART steel having a thickness of approximately 1.1 mm to 1.3 mm, which is 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 the ends of the second rear cross member 240 .

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

[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] The bottom surface of the rear subframe 250 may be provided with mounting brackets for fixing spring links of the suspension, and mounting brackets for mounting mount bushes for mounting the powertrain.

[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. A bolt hole is formed in the second connection bracket, and the second connection bracket may be bolted to a front cross member 251 on the rear subframe 250. The second connection bracket and the front cross member form a fourth connection position P4.

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

[0180] In this way, 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 one embodiment of the present invention, the installation position of the second connecting bracket 223 on the first rear cross member 220 constituting the fourth coupling position P4 can be determined according to the number of divisions of the space within the battery case 400.

[0182] For example, when the space inside 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 point 1 / 3 of the way along the width direction Y from the side frame 420 of the battery case 400. When the space inside 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 point 1 / 4 of the way along the width direction Y from the side frame of the battery case.

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

[0184] In the electric vehicle body according to one embodiment of the present invention, 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 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 connecting bracket and the front cross member of the rear subframe may be located at a height corresponding to the upper reinforcing member 432 of the reinforcing member 430 of the battery case.

[0185] For example, the reinforcing member 430 may be positioned so that its longitudinal axis intersects with the vertical 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 support 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.

[0189] Next, the rear side member 210 is connected at its side to the side seal 300 and at its end to the second rear cross member 240, so that excess collision load that has entered 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 transmitted to some of the members surrounding the battery space 40 below the floor panel while being connected to the rear side member.

[0191] Since deformation needs to be minimized within the battery space 40, it is necessary to prevent penetration of the collision load into the load support member. In a rear 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 part of the collision energy in the event of a rear 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 rear side frame 420 of the battery case 400, which is spaced a predetermined distance from the rear cross member 220, or the end of the lower reinforcement member 431, i.e., the rear protrusion 434. The rear side frame of the battery case is then 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 reinforcement 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 members 110 at the front, the rear side members 210 transmit part of the collision load to the reinforcing members 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 not only protect the battery space 40 but also support the load, and the rear side member 210, the rear subframe 250, the first rear cross member 220, and the battery case 400 can be organically connected to each other to form a load path.

[0200] In this way, 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 electric vehicles have the advantage of being able to ensure crashworthiness and safety despite the increased vehicle weight and reduced vehicle body space due to the inclusion of batteries, 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 serve as a path for the collision load and as a direct load support member, thereby distributing the load across the vehicle body in the event of a frontal or rearward collision, thereby efficiently suppressing 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 illustrative purposes only and do not limit the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention should not be limited by such embodiments. The scope of protection of the present invention should be interpreted by 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 member 431 Lower reinforcement 432 Upper reinforcement 434 Protrusion 440 mounting frame

Claims

1. a rear side member, one side of which is connected to the 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 of the vehicle body and coupled to the rear side member; a rear subframe coupled to the rear side member on one side and to the first rear cross member on the other side; and a battery case including a reinforcing member extending along the length of the vehicle body and coupled to the first rear cross member and the side seal; A body of an electric vehicle, wherein a fourth connection position where the rear subframe and the first rear cross member are connected is such that a cross section of the reinforcing member overlaps with an imaginary cross section extending in the longitudinal direction of the body.

2. The other side of the rear side member is bent downward to form an inclined portion, The electric vehicle body according to claim 1 , wherein one side of the inclined portion is fixed in contact with a side surface of the side seal.

3. 3. The electric vehicle body according to claim 2, further comprising a second rear cross member extending along the width direction of the vehicle body, connected to the side seal, and connected to an end of the rear side member.

4. 4. The electric vehicle body according to claim 3, wherein the second rear cross member is located forward of the first rear cross member and above the battery case.

5. 5. The electric vehicle body according to claim 4, wherein the second rear cross member is formed of a material having a higher strength than the first rear cross member.

6. The rear side member extends from the rear by a certain length in parallel to a center line extending in the longitudinal direction of the vehicle body, The rear side members are disposed on both the left and right sides in the width direction of the vehicle body, 2. The electric vehicle body according to claim 1, wherein the two rear side members are disposed so as to become more distant from each other toward the front of the vehicle body.

7. The first rear cross member is provided with a second connecting bracket extending in the longitudinal direction of the vehicle body, 2. The electric vehicle body according to claim 1, wherein the second connecting bracket and a front cross member of the rear subframe form the fourth coupling location.

8. the battery case includes a case body that houses battery cells, The case body includes: Multiple bottom plates; a side frame surrounding the plurality of bottom plates; and 8. The electric vehicle body according to claim 7, further comprising at least two of said reinforcing members disposed between said plurality of bottom plates and connected to said side frames at both longitudinal ends thereof.

9. 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 the side frame in a width direction; The electric vehicle body according to claim 8 , 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.

10. a rear protrusion of the lower reinforcement member spaced apart from a second connecting bracket of the first rear cross member and a front cross member of the rear subframe; The electric vehicle body according to claim 9 , wherein a rear side frame of the side frames is spaced apart from the first rear cross member.

11. 10. The electric vehicle carbody according to claim 9, wherein the fourth coupling location is located at a height corresponding to the upper stiffener.

12. 2. The electric car body according to claim 1, wherein a longitudinal axis of the reinforcing member intersects with a center line of the fourth connecting position in a height direction.

13. The lower reinforcement member has an inverted U-shaped cross section, The upper stiffener has a U-shaped cross section, The electric vehicle body according to claim 9 , wherein the hollow portion of the lower reinforcing member is disposed so as to be exposed to the outside of the battery case.

14. the case body further includes a mounting frame for fixing the battery case to a vehicle body; 10. The electric vehicle body according to claim 9, wherein the mounting frame is attached to the side frame away from a portion where the coupling groove is formed.

15. The end of the lower reinforcement member is sandwiched in the coupling groove to form a matching shape, The electric vehicle body according to claim 9 , wherein a weld is formed between the protrusion of the lower reinforcement member and the coupling groove.

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