Electric vehicle body structure

Abstract

The present invention relates to a body structure of an electric vehicle, and includes a battery frame formed to surround a battery area in which a battery is provided, and a front frame provided on the battery frame at the front side of the vehicle, the front frame including a first subframe connected to the battery frame, a second subframe branching from the first subframe and inclined outward in the width direction of the vehicle, and a third subframe extending from the first subframe at a branch point of the second subframe in front of the vehicle.

Description

[Technical Field]

[0001] The present invention relates to a body structure for an electric vehicle, and more particularly to a body structure for an electric vehicle that is equipped with a lightweight front frame that can absorb impact to the maximum extent possible in the event of a frontal collision of the vehicle. [Background technology]

[0002] Generally, in a body-on-frame vehicle, the body structure is formed by assembling a frame that forms the lower part and a body that includes the passenger space.

[0003] Unlike conventional body structures, electric vehicles typically place batteries inside the frame. When equipped with a battery, a typical body-on-frame structure makes it difficult to protect the battery without additional reinforcement against collisions.

[0004] In addition, since the cabin supports the space of the driver's seat, the driver of the automobile body operates the automobile body while sitting inside the cabin in the driver's seat.

[0005] Therefore, in order to ensure the safety of the driver during a frontal collision of the automobile body and prevent deformation of the frame in the battery area, the impact must be properly distributed to multiple components of the frame, and the front frame located at the front of the vehicle must absorb as much energy as possible.

[0006] Furthermore, there is a problem that the weight of the battery increases the weight of the entire vehicle, so the vehicle body must be designed so as not to become too heavy.

[0007] Crash tests are conducted using a frontal crash evaluation method for vehicles to assess the reliability of vehicle crash-related parts and vehicles.

[0008] The full frontal collision test involves crashing a vehicle into a completely fixed wall, and according to regulations, the vehicle is crashed into a fixed wall at a speed of 48 km / h or 56 km / h.

[0009] The partial frontal crash test involves crashing a portion of the front of the vehicle (40%) into a fixed wall at a speed of 64 km / h. While the full frontal crash test involves two front side members, this test involves only one part.

[0010] The small overlap crash test involves crashing a small portion (25%) of the front of a vehicle into a fixed wall at 64km / h. This test involves removing most of the front side members and inserting structures that are normally connected to the front side members to respond, or by removing them during the crash to transmit minimal impact to the occupants, thereby verifying the vehicle's reliability in a crash.

[0011] As described above, there is a need for a body structure for an electric vehicle that can effectively respond to a collision in a frontal collision test and solve the above problems. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Korean Patent No. 10-0352279 (August 28, 2002) Summary of the Invention [Problem to be solved by the invention]

[0013] The present invention has been made to solve the above problems, and aims to provide a lightweight body structure for an electric vehicle that can absorb a frontal collision of the vehicle to the maximum extent possible to protect the battery frame. [Means for solving the problem]

[0014] In order to achieve the above object, the present invention provides a body structure for an electric vehicle configured as follows.

[0015] The body structure of an electric vehicle according to one embodiment of the present invention includes a battery frame formed to surround a battery area in which a battery is provided, and a front frame provided on the battery frame at the front side of the vehicle, and the front frame includes a first subframe connected to the battery frame, a second subframe branching from the first subframe and inclined outward in the width direction of the vehicle, and a third subframe extending from the first subframe at a branch point of the second subframe in front of the vehicle.

[0016] The second sub-frame and the third sub-frame may be disposed at the same position in a height direction of the vehicle.

[0017] The cross section of the second sub-frame or the third sub-frame may include a plurality of closed cross sections.

[0018] The second subframe may include a first side member extending in the longitudinal direction of the vehicle and including a first groove formed in the width direction of the vehicle, and a second side member extending in the longitudinal direction of the vehicle, joining with the first side member to form a closed cross section, and including a second groove formed in the width direction of the vehicle toward the closed cross section, wherein the first groove and the second groove abut.

[0019] The first side member may be provided outward of the second side member in the width direction, and may have a first flat portion that is parallel to the second side member, and the shortest distance from the first flat portion to the first groove in the width direction may increase toward the front of the vehicle.

[0020] The third subframe may have a polygonal cross-sectional structure that is symmetrical in the height direction of the vehicle.

[0021] The third sub-frame may further include a reinforcing portion that crosses the closed cross section.

[0022] The third subframe may include a first auxiliary member arranged at an end of the vehicle in the height direction, and a second auxiliary member coupled to the first auxiliary member and having a contact portion that contacts at least one surface.

[0023] The third sub-frame may have a hollow interior and may include an outer member that is integrally provided therewith.

[0024] The suspension may further include a mounting bracket coupled to the first sub-frame, and a spring upper seat coupled to the mounting bracket.

[0025] The strength of the first sub-frame may be greater than the strength of the second sub-frame and the third sub-frame, or the thickness of the first sub-frame may be greater than the thickness of the second sub-frame and the third sub-frame. [Effects of the Invention]

[0026] The present invention, with the above-described structure, maximizes the absorption of energy from a frontal collision, protects the passengers and the battery, and reduces the weight of the vehicle body itself. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a perspective view of a body structure of an electric vehicle according to an embodiment of the present invention. [Figure 2] 1 is a view of a front frame according to an embodiment of the present invention as viewed from the height direction of the vehicle. [Figure 3] 1 is a view of a front frame according to an embodiment of the present invention as viewed from the side of a vehicle. [Figure 4] 3A to 3C are cross-sectional views showing cross sections of the second sub-frame taken along the lines AA', BB', and CC' shown in FIG. 2. [Figure 5] FIG. 10 is a cross-sectional view of a third sub-frame according to one embodiment of the present invention. [Figure 6]FIG. 10 is a cross-sectional view of a third sub-frame according to another embodiment of the present invention. [Figure 7] FIG. 10 is a cross-sectional view of a third sub-frame according to yet another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the concept of the present invention is not limited to the embodiments shown, and a person skilled in the art who understands the concept of the present invention can easily propose other regressive inventions or other embodiments within the concept of the present invention by adding, changing, or deleting other components within the scope of the same concept, and these can also be said to be included within the concept of the present invention.

[0029] FIG. 1 is a perspective view of a body structure of an electric vehicle according to one embodiment of the present invention.

[0030] The body structure of an electric vehicle according to one embodiment of the present invention includes a battery frame 100 and a front frame 200.

[0031] The battery frame 100 may be formed to surround a battery area where a battery is provided. The shape of the battery frame 100 is not limited, and it includes any frame surrounding a battery area. Since the battery frame 100 has a battery located therein, it protects the battery from external impact and protects the internal battery from being affected by external substances such as water.

[0032] The front frame 200 may be provided on the battery frame 100 at the front side of the vehicle. The front frame 200 may be configured to maximize impact absorption when an external force acts from the front of the vehicle, thereby minimizing the impact force transmitted to the battery frame 100 below.

[0033] For example, the front frame 200 may be made of a steel material, which can maximize the ability to absorb collision energy from a frontal impact and reduce the weight.

[0034] The body structure of the electric vehicle of the present invention may further include a side seal 600 provided on the battery frame 100, a floor 400 covering at least one side of the battery frame 100, a cross member 500 connected to the floor 400 and arranged parallel to the width direction of the vehicle, and a rear frame 300 connected to the battery frame 100 and located at the rear side of the vehicle.

[0035] FIG. 2 is a view of a front frame according to an embodiment of the present invention as seen from the height direction of the vehicle, and FIG. 3 shows the front frame as seen from the width direction of the vehicle, but from the outside to the inside of the vehicle.

[0036] The front frame 200 may include a first sub-frame 10, a second sub-frame 20, and a third sub-frame 30.

[0037] The first subframe 10 may be connected to the battery frame 100. The first subframe 10 is joined to the battery frame 100, and may be joined by an additional member such as a joining member, or may be joined together by direct welding or the like.

[0038] According to an embodiment of the present invention, the first sub-frame 10 may be formed with a bent portion. A folding phenomenon is likely to occur at the bent portion. Therefore, when an external impact occurs, a folding phenomenon occurs at the bent portion, which reduces deformation that enters the battery frame 100, and energy can be absorbed by folding at the bent portion. Therefore, the first sub-frame 10 has a bent portion, which provides an effect of increasing energy absorption capacity.

[0039] The second sub-frame 20 may branch off from the first sub-frame 10 and be inclined outward in the width direction of the vehicle.

[0040] As an example, the second subframe 20 may be connected via a connecting member 60 at a point where it branches off from the first subframe 10. The second subframe 20 may further include a connecting member 60 to facilitate connection at the branched portion where it branches off from the first subframe 10. By being connected to the connecting member 60, the strength of that portion can be supplemented.

[0041] In addition, this provides the effect of minimizing deformation of the first sub-frame 10.

[0042] The third sub-frame 30 may be formed from the front of the vehicle at the branch point of the second sub-frame 20 and extend from the first sub-frame 10.

[0043] The third sub-frame 30 may be connected to one end of the first sub-frame 10 and extend continuously in a straight line in the direction in which the one end of the first sub-frame 10 is formed.

[0044] As an example, the second subframe 20 and the third subframe 30 are each connected at one end to an end plate 70, and the end plate 70 stably distributes and transmits external forces acting on the second subframe 20 and the third subframe 30.

[0045] The end plate 70 may have a bent portion formed in a portion thereof, and the angle of the force that is drawn into the end plate 70 by the bent portion is transmitted in the same direction as the axis of the second sub-frame 20 or the third sub-frame 30, thereby helping to maximize absorption in the axial direction.

[0046] In full frontal collision tests and partial frontal collision tests, the third subframe 30 collapses in the axial direction of the third subframe 30, thereby maximizing the absorption of external collision energy, and the second subframe 20 can provide a complementary effect by absorbing some of the energy in an auxiliary manner.

[0047] In a small overlap crash test, the second subframe 20 collapses in the axial direction of the second subframe 20 to maximize energy absorption, and the third subframe 30 can additionally bend to complement the energy absorption.

[0048] Due to the above-mentioned effects, regardless of the direction from which an external collision occurs on the front, energy absorption is maximized by the second subframe 20 and the third subframe 30, thereby minimizing the energy transmitted to the first subframe 10 and minimizing deformation of the first subframe 10 and the battery frame 100.

[0049] When the absorption of collision energy in the second subframe 20 and the third subframe 30 is maximized, the collision load transmitted to the first subframe 10 is reduced, and the first subframe 10 can be constructed while avoiding further weight increases due to shape changes such as increased thickness or material changes, thereby providing the effect of reducing weight.

[0050] According to one embodiment of the present invention, the second sub-frame 20 and the third sub-frame 30 may be disposed at the same position in the height direction of the vehicle.

[0051] The second sub-frame 20 and the third sub-frame 30 may be positioned at the same height in the vehicle height direction. Therefore, the second sub-frame 20 and the third sub-frame 30 are both positioned at the same height with one end connected to the first sub-frame 10, and the collision energy is transmitted to and absorbed by the second sub-frame 20 and the third sub-frame 30 without being concentrated in a specific part.

[0052] According to one embodiment of the present invention, the strength of the first sub-frame 10 may be greater than the strength of the second sub-frame 20 and the third sub-frame 30. Alternatively, the thickness of the first sub-frame 10 may be greater than the thickness of the second sub-frame 20 and the third sub-frame 30.

[0053] The strength of the first subframe 10 may be greater than the strength of the second subframe 20 and the third subframe 30 so that the amount of deformation of the first subframe 10 is minimized, while the second subframe 20 and the third subframe 30 are configured to deform and absorb as much of the impact energy as possible.

[0054] In addition, the thickness of the first subframe 10 may be thicker than the thickness of the second subframe 20 and the third subframe 30, so that the amount of deformation of the first subframe 10 is minimized, while the second subframe 20 and the third subframe 30 are configured to deform and absorb as much of the impact energy as possible.

[0055] Furthermore, the first sub-frame 10 may be formed to be greater in both strength and thickness than the second sub-frame 20 and the third sub-frame 30 .

[0056] According to an embodiment of the present invention, the front frame 200 may further include a mounting bracket 50 coupled to the first sub-frame 10 and a spring upper seat 40 coupled to the mounting bracket 50 .

[0057] The front frame 200 may further include a mounting bracket 50 and a spring upper seat 40 coupled to the mounting bracket 50 .

[0058] The mounting bracket 50 may have an upper arm formed thereon that is positioned higher in the vehicle height direction of the first subframe 10 and may be coupled to the first subframe 10. In addition, the spring upper seat 40 is coupled to the first subframe 10 via the mounting bracket 50, and provides the effect of absorbing impacts received by the vehicle body using a spring.

[0059] FIG. 4 is a cross section of the second subframe according to an embodiment of the present invention taken in the width direction of the vehicle, showing cross sections taken along points A-A', B-B', and C-C' shown in FIG.

[0060] The second sub-frame 20 according to an embodiment of the present invention may have a cross section that includes multiple closed cross sections.

[0061] A cross section of the second subframe 20 taken parallel to the vehicle width direction may include multiple closed cross sections C1, C2. The hollow configuration reduces weight and guides deformation in a certain direction, preventing damage to other components due to unpredictable deformation.

[0062] As an example, the second sub-frame 20 may include a first side member 21 and a second side member 22.

[0063] The first side member 21 and the second side member 22 may be joined at both ends in the vehicle height direction, and multiple closed cross sections may be formed inside the first side member 21 and the second side member 22 when they are joined together.

[0064] The first side member 21 may extend in the length direction of the vehicle and include a first groove 21a formed in the width direction of the vehicle. The first side member 21 may also be formed with a first flange 21c bent in the same direction as the recessed direction of the first groove 21a at both ends in the height direction of the vehicle. Furthermore, the first side member 21 may be formed with a first flat portion 21b having a predetermined length in the height direction of the vehicle, and the first groove 21a may be included in a portion of the first flat portion 21b.

[0065] The second side member 22 may extend in the longitudinal direction of the vehicle, be joined to the first side member 21 to form a closed cross section, and include a second groove 22a formed in the width direction of the vehicle toward the closed cross section. The second side member may be formed with second flanges 22c bent in the same direction as the recessed direction of the second groove 22a at both ends in the height direction of the vehicle. The second side member 22 may also include a second flat portion 22b parallel to the first flat portion 21b, and the second groove 22a may be formed by recessing a portion of the second flat portion 22b in the outward width direction of the vehicle.

[0066] The first side member 21 and the second side member 22 may be joined by the first flange 21c and the second flange 22c, and may be positioned so that the first groove 21a and the second groove 22a abut against each other.

[0067] The recessed depths of the first groove 21a and the second groove 22a may vary along the length of the vehicle, but the first groove 21a and the second groove 22a may extend along the length of the vehicle, and the first groove 21a and the second groove 22a may always abut against each other even at different points along the length of the vehicle.

[0068] Therefore, a closed cross section is formed above and below in the vehicle height direction, based on the portion where the first groove 21a and the second groove 22a abut against each other.

[0069] In addition, the first side member 21 may be provided outside the second side member 22 in the width direction, and may have a first flat portion 21b that is parallel to the second side member 22, and the shortest distance from the first flat portion 21b to the first groove 21a in the width direction may be greater toward the front of the vehicle.

[0070] The first side member 21 is formed closer to the outside of the vehicle in the width direction of the vehicle than the second side member 22, and the first groove 21a is formed to be deeply recessed in the first side member 21 at the front of the vehicle, and the amount of recession of the first groove 21a becomes smaller as it approaches the part connected to the first subframe 10, so that the amount of recession of the first groove 21a disappears at the part connected to the first subframe 10 and the part may be flat.

[0071] In addition, the second side member 22 may be provided inward from the second side member 22 in the width direction, and may have a second flat portion 22b parallel to the first flat portion 21b of the first side member 21, and the shortest distance from the second flat portion 22b to the second groove 22a in the width direction may be made larger toward the rear of the vehicle.

[0072] The first groove 21a and the second groove 22a may be beads formed by a beading process.

[0073] Because the second subframe 20 is configured in the above-described shape, the axial load is transmitted more toward the inside of the vehicle width direction at the front of the vehicle, which has the effect of offsetting the outward moment in the vehicle width direction generated on the third subframe 30. However, if the same cross section continues in the length direction of the vehicle, the axial load may continue to act on the inside of the vehicle, causing a problem of inward bending deformation of the vehicle. Therefore, when moving relatively toward the rear of the vehicle, the first grooves 21a are formed so that their depth gradually decreases toward the outside in the vehicle width direction, as shown in the cross section in the vehicle width direction, thereby preventing inward bending deformation and inducing collapse in the axial direction of the second subframe 20.

[0074] 5 to 7 are cross-sectional views of the third sub-frame according to the embodiment of the present invention taken in the width direction of the vehicle, and show the shapes of the respective embodiments.

[0075] The third sub-frame 30 according to an embodiment of the present invention may have a cross section that includes a plurality of closed cross sections C3 and C4.

[0076] Furthermore, the polygonal cross-sectional structure of the third sub-frame 30 may be symmetrical in the height direction of the vehicle.

[0077] Since the third sub-frame 30 forms closed cross sections C3 and C4, it is possible to reduce the weight while maintaining a predetermined rigidity. Furthermore, during deformation, it is possible to induce deformation in a specific direction.

[0078] The third subframe 30 may have a polygonal cross-sectional structure that is symmetrical in the vehicle height direction. For example, it may have an octagonal cross-sectional shape. However, the shape of the polygonal structure can be changed depending on the design.

[0079] Furthermore, the structure may be symmetrical above and below a predetermined point.

[0080] The third subframe 30 has a polygonal cross section and is formed in a shape that is symmetrical in the height direction of the vehicle. Therefore, when energy from a frontal collision is applied to the third subframe 30, bending deformation does not occur, and the third subframe 30 acts to absorb the energy by inducing collapse in the axial direction of the third subframe 30.

[0081] Referring to FIG. 5, the third subframe 30 may include a first auxiliary member 31 arranged at an end in the height direction of the vehicle, and a second auxiliary member 32 coupled to the first auxiliary member 31 and having a contact portion 33 that contacts at least one surface.

[0082] The first auxiliary member 31 is disposed at both ends in the vehicle height direction, and a second auxiliary member 32 is provided to be connected to the first auxiliary member 31. The first auxiliary member 31 and the second auxiliary member 32 form a connection part at a portion thereof, and for example, the first auxiliary member 31 may be fitted into the second auxiliary member 32, and the first auxiliary member 31 and the second auxiliary member 32 may be connected by welding or the like, or may be fixed by a mechanical connection method such as bolting.

[0083] In addition, the second auxiliary members 32 may have a plurality of bent portions formed thereon, and a contact portion 33 formed on one surface thereof, so that the second auxiliary members 32 are joined to each other symmetrically with respect to the contact portion 33.

[0084] In addition, the first auxiliary member 31 and the second auxiliary member 32 may be continuous in the longitudinal direction of the vehicle, connected to the end plate 70 at the front end of the vehicle, and connected to the first subframe 10 at the other end.

[0085] Referring to FIG. 6, the third sub-frame 30 may further include a reinforcing portion 34 that crosses the closed cross section.

[0086] As described above, the first auxiliary member 31 and the second auxiliary member 32 are joined together to form a closed cross section therein, and the reinforcement portion 34 may be further provided across the closed cross section.

[0087] The reinforcing portion 34 may be formed to cross the closed cross section in the width direction of the vehicle. By providing the reinforcing portion 34, the closed cross section formed inside the first subframe 10 is divided, and the size of the closed cross section is reduced and multiple closed cross sections are formed, which provides the effect of increasing the critical load at which bending deformation begins.

[0088] As an example, the reinforcing portion 34 may be formed integrally with the first auxiliary member 31.

[0089] The first auxiliary member 31 and the reinforcing portion 34 are integrally formed, and the connecting portion to be connected to the second auxiliary member 32 is formed to be small, which can provide convenience in processing.

[0090] Referring to FIG. 7, the third sub-frame 30 may include an outer member 36 that is hollow inside and is provided integrally therewith.

[0091] In yet another embodiment, the third subframe 30 may be formed of an outer member 36. The outer member 36 may be formed by extrusion molding, or may be formed by bending a single plate material and then joining both ends together to form a single member.

[0092] Even when configured with outer members 36, they may be arranged in a shape that is symmetrical in the height direction of the vehicle, and when a joint is formed by bending and joining a single plate material, the joint may be located at the contact portion 33 where the outer members 36 come into contact with each other.

[0093] A reinforcing portion 35 may be formed inside the outer member 36, and the reinforcing portion 35 may be formed to cross a closed cross section inside the outer member 36, and may be connected to the outer member 36 by forming a reinforcing flange 35a.

[0094] The reinforcing flange 35a may be arranged to face upward when coupled to the outer member 36 provided at the upper end of the vehicle in the height direction, and may be arranged to face downward when coupled to the outer member 36 provided at the lower end.

[0095] By forming the third subframe 30 into the shape described above, it is possible to provide the effects of efficiently absorbing impacts from the front of the vehicle, minimizing the impact transmitted to the first subframe 10, and reducing weight.

[0096] The third sub-frame 30 is not limited to the shape described above, and can be modified in various ways depending on the design.

[0097] The present invention has been described above with reference to the preferred embodiments. However, the present invention is not limited to the above-described preferred embodiments, and it goes without saying that modifications can be made by those skilled in the art without changing the technical concept of the present invention as claimed in the claims. [Explanation of symbols]

[0098] 10 First subframe 20 Second subframe 21 First side member 21a 1st groove 22 second side member 22a 2nd groove 30 Third subframe 31 First auxiliary member 32 Second auxiliary member 33 Contact area 34, 35 Reinforcement 36 Outer member 40 Spring upper seat 50 Mounting bracket 60 Connecting member 70 End Plate 100 Battery Frame 200 front frame 300 rear frame 400 floors 500 cross member 600 Side Seal

Claims

1. a battery frame formed to surround a battery area in which a battery is provided; a front frame provided on the battery frame at a front side of the vehicle, The front frame is a first sub-frame connected to the battery frame; a second subframe branching from the first subframe and inclined outward in a width direction of the vehicle; a third subframe extending from the first subframe forward of the vehicle from a branch point of the second subframe.

2. The electric vehicle body structure according to claim 1 , wherein the second sub-frame and the third sub-frame are disposed at the same position in a height direction of the vehicle.

3. The body structure for an electric vehicle according to claim 1 , wherein a cross section of the second sub-frame or the third sub-frame includes a plurality of closed cross sections.

4. The second subframe is a first side member extending in a length direction of the vehicle and including a first groove formed in a width direction of the vehicle; a second side member extending in the length direction of the vehicle, coupled to the first side member to form a closed cross section, and including a second groove formed in the width direction of the vehicle toward the closed cross section; The electric vehicle body structure according to claim 1 , wherein the first groove and the second groove abut each other.

5. The first side member is The second side member is provided on the outer side in the width direction, a first flat portion that is a portion parallel to the second side member is formed; 5. The body structure of an electric vehicle according to claim 4, wherein a minimum distance from the first flat portion to the first groove in the width direction increases toward the front of the vehicle.

6. The third subframe is The electric vehicle body structure according to claim 3 , wherein the polygonal cross-sectional structure is symmetrical in the height direction of the vehicle.

7. The third subframe is The electric vehicle body structure according to claim 6 , further comprising a reinforcing portion that crosses the closed cross section.

8. The third subframe is a first auxiliary member disposed at an end of the vehicle in a height direction; The body structure of an electric vehicle according to claim 6 , further comprising: a second auxiliary member coupled to the first auxiliary member and having a contact portion formed thereon that contacts at least one surface of the second auxiliary member.

9. The third subframe is 7. The body structure of an electric vehicle according to claim 6, further comprising an outer member having a hollow interior and being integrally provided.

10. a mounting bracket coupled to the first subframe; The electric vehicle body structure according to claim 1 , further comprising: a spring upper seat coupled to the mounting bracket.

11. The strength of the first subframe is greater than the strength of the second sub-frame and the third sub-frame, or The thickness of the first subframe is The body structure of an electric vehicle according to claim 1 , wherein the thickness of the second sub-frame is greater than that of the third sub-frame.

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