Vehicle body for electric vehicle

Abstract

To provide a vehicle body for an electric vehicle capable of preventing impact energy from being transmitted to a high-voltage battery by improving the structure of a vehicle body rear part.SOLUTION: A vehicle body for an electric vehicle according to the present invention includes: side sills which are coupled to the side surfaces of a floor panel in a front-rear longer direction; rear side members which have front end parts overlapping the rear end parts of the side sills, and which extend rearward along the side surfaces of the floor panel to be coupled; a battery which is located at the lower part of the floor panel, and which is mounted to the side sill portions in front of the rear side members and to portions where the side sills and the rear side members overlap; and rear extension members which are formed so as to have lower strength than the side sills and the rear side members, which have front ends coupled to the rear ends of the rear side members, and which extend rearward along the side surfaces of the floor panel to be coupled.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vehicle body for an electric vehicle capable of preventing the transmission of impact energy to a high-voltage battery by improving the structure of the rear part of the vehicle body.

Background Art

[0002] Existing internal combustion engine vehicles have a body structure developed with an emphasis on protecting the fuel tank during a rear collision. The reason is that if the fuel tank is damaged and fuel leakage occurs, it may lead to a fire in the vehicle, which can cause significant losses to the passengers and the surrounding area of the accident site. On the other hand, in the case of an electric vehicle, instead of a fuel tank, there is a high-voltage battery. Therefore, if the high-voltage battery is damaged by a rear collision, it may also lead to a fire. Thus, it is necessary to protect the high-voltage battery during a rear collision of an electric vehicle.

[0003] However, the existing body structure is mainly optimized for protecting the fuel tank of an internal combustion engine vehicle. Moreover, the high-voltage battery has a different shape, arrangement form, and structure inside the vehicle compared to the fuel tank. Therefore, there is a problem that the existing body structure cannot normally protect the high-voltage battery. For this reason, there is a need for a body structure that can minimize damage to the high-voltage battery in the event of a rear collision of an electric vehicle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle body for an electric vehicle that can prevent impact energy from being transmitted to a high-voltage battery by improving the structure of the rear part of the vehicle body.

Means for Solving the Problems

[0006] The vehicle body for an electric vehicle according to the present invention includes a side sill longitudinally coupled in the front-rear direction to a side surface of a floor panel, a rear side member having a front end overlapping a rear end of the side sill and extending rearward along the side surface of the floor panel and coupled thereto, a battery mounted at a lower portion of the floor panel, at a side sill portion in front of the rear side member, and at a portion where the side sill and the rear side member overlap, and a rear extension member formed to have a lower strength than the side sill and the rear side member, having a front end connected to a rear end of the rear side member, and extending rearward along the side surface of the floor panel and coupled thereto.

[0007] The rear end portion of the rear side member and the front end portion of the rear extension member are overlapped and coupled.

[0008] A spring seat is coupled to a bottom surface of a portion where the rear side member and the rear extension member overlap.

[0009] The vehicle body for an electric vehicle further includes a first cross member connected between rear side members on both sides and having a battery mounted in the middle.

[0010] The vehicle body for an electric vehicle further includes a second cross member connected between rear extension members on both sides, and sub-frames are mounted at both ends of the first cross member connected to the rear side member and at both ends of the second cross member connected to the rear extension member.

[0011] The first cross member is characterized by being coupled to a rear side member located behind an overlap section where a side sill and the rear side member overlap.

[0012] A battery mounting portion is provided on the rear surface of the middle portion of the first cross member, and a battery mount bracket is vertically connected between the battery mounting portion and the battery.

[0013] The battery mounting portion is characterized by being configured by separately coupling a mounting bracket to the rear surface of the first cross member or being configured from a predetermined mounting plane formed on the rear surface of the first cross member.

[0014] The lower end of the battery mount bracket is coupled to the rear end of the battery, and the upper end of the battery mount bracket is coupled to the battery mounting portion.

[0015] The vehicle body for an electric vehicle further includes a second cross member connected between rear extension members on both sides and a mount reinforcement member connected between the first cross member and the second cross member.

[0016] The mount reinforcement member is characterized by being connected front and rear between a battery mount portion and the front end of the second cross member.

Advantages of the Invention

[0017] According to the present invention, the vehicle body structure at the rear of the vehicle can be optimized to prevent collision energy from being transmitted to the battery. Further, the battery can be safely protected, a fire caused by battery damage can be prevented, and passengers can be safely protected.

Brief Description of the Drawings

[0018]

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Mode for Carrying Out the Invention

[0019] Examples of the present invention will be described in detail based on the accompanying drawings.

[0020] FIG. 1 is a diagram illustrating the mounting position of a high-voltage battery 700 mounted on the lower part of a vehicle body according to the present invention, and FIG. 2 is a diagram showing the structure of the lower part of the vehicle body with the battery 700 mounted therein according to the present invention. As shown in FIGS. 1 and 2, a floor panel is attached to the lower part of the vehicle body, and the floor panel includes a center floor panel 10 at the center of the lower part of the vehicle body and a rear floor panel 20 connected to the rear of the center floor panel 10. And, a high-voltage battery 700 (hereinafter referred to as 'battery') having a size corresponding to its width and length is mounted below the center floor panel 10. Therefore, the battery 700 is mounted and fastened to the members forming the vehicle body around the battery 700, and the battery 700 can be stably coupled to the vehicle body by such mounting and fastening.

[0021] On the other hand, FIGS. 3 and 4 are diagrams for explaining a side sill 100 and an overlap section OL of a vehicle body according to the present invention, FIGS. 5 and 6 are diagrams for explaining a rear side member 200 and an overlap section OL of a vehicle body according to the present invention, and FIGS. 7 and 8 are diagrams for explaining a configuration in which a rear side member 200 and a rear extension member 300 of a vehicle body according to the present invention are coupled.

[0022] Referring to FIGS. 3 and 4, a side sill 100 is longitudinally coupled to the side surface of the center floor panel 10 in the front-rear direction. For example, one side surface of the side sill 100 is coupled to the outer surface of the center floor panel 10. For reference, a reinforcing member having a lattice-shaped cross-sectional structure can be further provided inside the side sill 100. And, referring to FIGS. 5 and 6, the front end portion of the rear side member 200 overlaps and is coupled to the rear end portion of the side sill 100, and the rear side member 200 extends rearward and is coupled along the side surface of the rear floor panel 20 connected to the rear of the center floor panel 10.

[0023] For example, one side surface of the rear side member 200 is coupled to the outer side surfaces of the center floor panel 10 and the rear floor panel 20. In particular, in the overlap section OL where a part of the rear side member 200 overlaps with a part of the side sill 100, the front end of the rear side member 200 can be coupled to the side surface of the center floor panel 10 in such a form that the rear end of the side sill 100 overlaps with the front end of the rear side member 200. Of course, it can also be coupled in such a form that the rear end of the side sill 100 is coupled to the side surface of the center floor panel 10 and the front end of the rear side member 200 overlaps with that side surface.

[0024] For reference, since the side surface of the portion connecting the center floor panel 10 to the rear floor panel 20 is formed in a shape bent toward the inside of the vehicle body, the front end of the rear side member 200 is formed along the front and rear of the side surface of the center floor member, and the rear end is formed to bend along the side surface of the rear floor panel 20. Also, referring to FIG. 2, the battery 700 is located below the center floor panel 10, and the side surface of the battery 700 is mounted on the side sill 100 portion in front of the rear side member 200 and the portion where the side sill 100 and the rear side member 200 overlap.

[0025] For example, brackets are provided on the outer periphery of the battery 700, and by positioning the brackets below the side sill 100 and the rear side member 200, points where the battery 700 is mounted on the side sill 100 and the overlap section OL are provided. Here, at least one point (battery mounting point) or more is provided in the side sill 100 section located in front of the overlap section OL, and at least one point (battery mounting point) or more is provided in the overlap section OL. Preferably, two or more battery mounting points M1 are provided in each section.

[0026] Then, referring to FIGS. 7 and 8, a rear extension member 300 having a lower strength than the side sill 100 and the rear side member 200 is formed, and the front end of the rear extension member 300 is connected to the rear end of the rear side member 200. Further, the rear extension member 300 is structured to extend rearward along the side surface of the rear floor panel 20 and be joined. For example, one side surface of the rear extension member 300 is structured to be joined to the outer side surface of the rear portion of the rear floor panel 20.

[0027] That is, as shown in FIGS. 2 and 12, the present invention can divide the section from the portion of the side sill 100 in front of the overlap section OL to the rear end portion of the rear extension member 300 into a first energy absorption section, a second energy absorption section, a first protection section, and a second protection section. Therefore, when a collision occurs at the rear of the vehicle, since the strength of the rear extension member 300 is lower than that of the rear side member 200 and the side sill 100 in front of it, the rear extension member 300 is compressed and deformed and collapses in the first energy absorption section to primarily absorb the collision energy. And in the second energy absorption section, since the rear side member 200 made of a member having a higher strength than the rear extension member 300 is provided, the rear side member 200 is bent and deformed while further absorbing the collision energy that could not be absorbed in the first energy absorption section.

[0028] On the one hand, since the second protection section is the section where the battery 700 is located, deformation of this section must be prevented. However, since the second protection section corresponds to the section of the bending part where the center floor panel 10 and the rear floor panel 20 are bent and connected and there is a risk of deformation, it is composed of an overlap section OL where the high-strength side sill 100 and the rear side member 200 overlap and are joined, thereby increasing the strength of this section to prevent deformation. Also, the first protection section is the section composed of the side sill 100, and the first protection section is also prevented from deforming by the rigidity of the side sill 100. In this way, the vehicle body structure at the rear of the automobile is optimized to prevent the collision energy from being transmitted to the battery 700. Thereby, the battery 700 can be safely protected, the occurrence of a fire due to damage to the battery 700 can be prevented, and the passengers can be protected.

[0029] On the other hand, referring to FIGS. 7, 8, and 12, the structure is such that the rear end portion of the rear side member 200 and the front end portion of the rear extension member 300 overlap and are joined. For example, the rear end of the rear side member 200 is joined to the side surface of the rear floor panel 20, and the front end of the rear extension member 300 overlaps the rear end of the rear side member 200. Also, as another example, the front end of the rear extension member 300 is joined to the side surface of the rear floor panel 20, and the rear end of the rear side member 200 overlaps the front end of the rear extension member 300. And a spring seat 210 is joined to the bottom surface of the overlapping portion of the rear side member 200 and the rear extension member 300.

[0030] Therefore, by increasing the strength of the overlapping portion of the rear side member 200 and the rear extension member 300, when a collision occurs at the rear of the automobile, the overlapping portion does not break, and thereby the spring seat 210 is not deformed, preventing damage to the suspension mechanism portion supported by the spring seat 210.

[0031] On the one hand, referring to FIG. 2, a first cross member 400 is connected between the rear side members 200 on both sides, and a battery mounting point M1 where a battery 700 is mounted is secured in the middle of the first cross member 400. Specifically, both ends of the first cross member 400 are respectively coupled to the left and right rear side members 200 located behind the overlap section OL, and the middle portion of the first cross member 400 is coupled so as to horizontally cross the bottom surface of the floor panel from left to right. And two battery mounting points M1 of the first cross member 400 are respectively provided between the middle and both ends of the first cross member 400, and the battery 700 is mounted on these points, forming such a structure.

[0032] Also, a second cross member 500 is connected between the rear extension members 300 on both sides. For example, both ends of the second cross member 500 are respectively coupled to the left and right rear extension members 300 located behind the spring seat 210, and the middle portion of the second cross member 500 is coupled so as to horizontally cross the bottom surface of the rear floor panel 20 from left to right.

[0033] In particular, sub-frame mounting points M2 where a sub-frame 800 is mounted are provided at both ends of the first cross member 400 connected to the rear side member 200 and at both ends of the second cross member 500 connected to the rear extension member 300. That is, as shown in FIG. 9, both front ends of the sub-frame 800 are mounted at both ends of the first cross member 400, and both rear ends of the sub-frame 800 are mounted at both ends of the second cross member 500, so that the four corners of the sub-frame 800 are respectively coupled to the rear side member 200 and the rear extension member 300 to stably couple and support the sub-frame 800 to the vehicle body. Here, each of the first cross member 400 and the second cross member 500 can have a structure in which bracket portions at both ends coupled to the rear side member 200 and the rear extension member 300 and member portions formed long in the middle are integrally formed. As another example of the first cross member 400 and the second cross member 500, the bracket portion and the member portion can each have a structure composed of separate parts.

[0034] On the other hand, referring to FIGS. 2 and 13, a battery mounting portion is provided on the rear surface of the middle portion of the first cross member 400, and a battery mount bracket 710 can be connected vertically between the battery mounting portion and the battery 700. Specifically, the lower end of the battery mount bracket 710 is coupled to the rear end of the battery 700, and the upper end of the battery mount bracket 710 is coupled to the battery mounting portion. Therefore, not only can the battery 700 be mounted on the side sill 100 and the overlap section OL, but also by mounting the battery 700 on the first cross member 400, the battery 700 can be fastened and supported more stably.

[0035] FIG. 10 shows a form in which a mounting bracket 410 as a first embodiment of the battery mounting portion according to the present invention is separately coupled, and FIG. 11 shows a form in which a mounting plane 420 as a second embodiment of the battery mounting portion according to the present invention is formed. Referring to FIG. 10, the battery mounting portion can be configured by separately coupling a mounting bracket 410 to the rear surface of the first cross member 400. And referring to FIG. 11, the battery mounting portion can be formed such that a predetermined mounting plane 420 on the rear surface of the first cross member 400 has a shape facing the second cross member 500.

[0036] That is, the battery mounting portion is a battery mount point M1 where the battery 700 is mounted, and the battery 700 can be mounted by being coupled to the first cross member 400 as a separate bracket form, or the battery 700 can also be mounted by being integrally formed on the first cross member 400.

[0037] On the one hand, referring to FIGS. 2 and 13, a mount reinforcement member 600 can be connected between the first cross member 400 and the second cross member 500. Such a mount reinforcement member 600 is structured to be connected longitudinally between the battery mount portion and the front end of the second cross member 500. That is, by connecting the mount reinforcement member 600 between the first cross member 400 and the second cross member 500, the rigidity of the floor panel between the first cross member 400 and the second cross member 500 is reinforced. In particular, by connecting the mount reinforcement member 600 to the battery mount portion which is the battery mount point M1 on the first cross member 400, the battery mount portion is physically reinforced to mount the battery 700 more firmly.

[0038] That is, the battery 700 is firmly mounted at the battery mount point M1 located in the side sill 100 and the overlap section OL, and the battery 700 is also firmly mounted at the battery mount portion. Thus, the battery 700 is mounted more firmly than by the battery mount bracket 710 alone. Therefore, if a collision occurs at the rear of the vehicle as shown in FIG. 13, since the battery 700 is firmly mounted at each battery mount point M1 as a whole, when the subframe 800 strikes the battery mount bracket 710, the battery mount bracket 710 is broken quickly without bending or deforming, so that the rear end of the battery 700 does not fold in any one direction and maintains its original state.

[0039] In this way, the present invention optimizes the vehicle body structure at the rear of the vehicle to prevent collision energy from being transmitted to the battery 700, thereby safely protecting the battery 700, preventing a fire caused by damage to the battery 700, and protecting the passengers. Although the present invention has been described with specific embodiments, it will be apparent that it can be implemented in various ways.

Description of Reference Numerals

[0040] 10 Center Floor Panel 20 Rear Floor Panel 100 Side Sill 200 Rear Side Member 210 Spring Seat 300 Rear Extension Member 400 First Cross Member 410 Mounting Bracket 420 Mounting Plane 500 Second Cross Member 600 Mounting Reinforcement Member 700 Battery 710 Battery Mounting Bracket 800 Subframe OL Overlap Section M1 Battery Mounting Point M2 Subframe Mounting Point

Claims

1. A side sill longitudinally coupled in the front-rear direction to a side surface of a floor panel, A rear side member having a front end overlapping with a rear end of the side sill and extending rearward along the side surface of the floor panel and being coupled, A battery mounted at a lower portion of the floor panel, at a side sill portion in front of the rear side member, and at an overlap section where the side sill and the rear side member overlap and are coupled, A rear extension member formed to have a lower strength than the side sill and the rear side member, having a front end connected to the rear end of the rear side member, and extending rearward along the side surface of the floor panel and being coupled, and Further including a first cross member coupled between rear side members on both sides, with a battery mounted in the middle, A battery mounting portion is provided at a rear portion of an intermediate portion of the first cross member, and a battery mounting bracket is vertically coupled between the battery mounting portion and the battery, characterized in that it is a vehicle body for an electric vehicle.

2. The vehicle body for an electric vehicle according to claim 1, characterized in that a rear end portion of the rear side member and a front end portion of the rear extension member overlap and are coupled.

3. The vehicle body for an electric vehicle according to claim 2, characterized in that a spring sheet is coupled to a bottom surface of a portion where the rear side member and the rear extension member overlap.

4. Further including a second cross member coupled between rear extension members on both sides, The vehicle body for an electric vehicle according to claim 1, characterized in that sub-frames are mounted at both ends of the first cross member coupled to the rear side member and at both ends of the second cross member coupled to the rear extension member.

5. The vehicle body for an electric vehicle according to claim 1, characterized in that the first cross member is coupled to a rear side member located behind an overlap section where the side sill and the rear side member overlap.

6. The vehicle body for an electric vehicle according to claim 1, characterized in that the battery mounting portion is configured by separately coupling a mounting bracket to a rear portion of the first cross member or is configured from a predetermined mounting plane formed at a rear portion of the first cross member.

7. The lower end of the battery mount bracket is coupled to the rear end of the battery, and the upper end of the battery mount bracket is coupled to the battery mounting portion. The vehicle body for an electric vehicle according to claim 1, characterized in that.

8. A second cross member connected between the rear extension members on both sides, The vehicle body for an electric vehicle according to claim 1, further comprising a mount reinforcing member connected between the first cross member and the second cross member.

9. The mount reinforcing member is connected back and forth between the battery mount portion and the front end of the second cross member. The vehicle body for an electric vehicle according to claim 8, characterized in that.

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