Skateboard platform for electric vehicle

An embodiment skateboard platform for an electric vehicle includes a skateboard frame including a center module, a front module connected to a front of the center module, and a rear module connected to a rear of the center module, and a battery assembly mounted on the skateboard frame, wherein the battery assembly is detachably connected to the center module.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 10-2021-0063642, filed on May 17, 2021, in the Korean Intellectual Property Office, which application is hereby incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a skateboard platform for an electric vehicle.

BACKGROUND

In recent years, as the perception of environmental crisis and depletion of oil resources has increased, research and development of eco-friendly electric vehicles have actively been conducted. Electric vehicles include plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), fuel cell electric vehicles (FCEVs), etc.

An electric vehicle includes a battery assembly mounted on a vehicle body. The battery assembly (also referred to as the “battery pack”) includes a battery case in which a plurality of battery modules, cooling channels, and other electric/electronic components are assembled. Each battery module includes a plurality of battery cells.

In order to develop a purpose built vehicle (PBV) that satisfies various customers' needs (a flat floor, expansion of an interior space, etc.), electric vehicles in which one or more upper bodies having various structures or shapes share a common skateboard platform are being researched and developed. Such an upper body is also referred to as a “top hat”, and the upper body may be of various body styles, such as a crossover, a sedan, and a coupe.

A skateboard platform includes a skateboard frame and a battery assembly mounted on the skateboard frame. However, a conventional skateboard platform has a structure in which the battery assembly overlaps the skateboard frame, which increases weight and cost, and an unnecessary space is created between the skateboard frame and the battery assembly in terms of layout. As a result, the manufacturing cost and weight of the electric vehicle relatively increase.

The above information described in this background section is provided to assist in understanding the background of the inventive concept, and may include any technical concept which is not considered as the prior art that is already known to those skilled in the art.

SUMMARY

The present disclosure relates to a skateboard platform for an electric vehicle. Particular embodiments relate to a skateboard platform for an electric vehicle in which a battery assembly is integrally connected to a center module of a skateboard frame.

Embodiments of the present disclosure can solve problems occurring in the prior art while advantages achieved by the prior art are maintained intact.

An embodiment of the present disclosure provides a skateboard platform for an electric vehicle allowing a battery assembly to be integrally connected to a center module of a skateboard frame, thereby increasing the overall stiffness of a vehicle body which is uniformly distributed through the battery assembly, and reducing the overall number of components which results in reduced weight and cost.

According to an embodiment of the present disclosure, a skateboard platform for an electric vehicle may include a skateboard frame including a center module, a front module connected to the front of the center module, and a rear module connected to the rear of the center module, and a battery assembly mounted on the skateboard frame. The battery assembly may be detachably connected to the center module.

The battery assembly may include an upper panel, a lower panel located below the upper panel, and a plurality of battery modules disposed between the upper panel and the lower panel, and the upper panel and the lower panel may be detachably joined to the center module through fasteners.

The center module may include a pair of center side members each extending in a longitudinal direction of the vehicle, and the upper panel and the lower panel may be detachably joined to the pair of center side members through the fasteners.

The upper panel may have a pair of side walls facing the exterior of the vehicle, and a pair of upper flanges each extending from each side wall toward the exterior of the vehicle, and the pair of upper flanges may be joined to the pair of center side members through the fasteners, respectively.

The side wall may extend from each side edge of the upper panel to a top surface of the center side member, the upper flange may extend from a bottom end of the side wall toward the center side member, and the upper flange may be joined to the top surface of the center side member through the fastener.

The center side member may have a mounting surface recessed from the top surface thereof toward a bottom surface thereof, and the upper flange of the upper panel may be joined to the mounting surface through the fastener.

An upper sealing member may be interposed between the upper flange and the top surface of the center side member.

The side wall may extend from each side edge of the upper panel to a bottom surface of the center side member, the upper flange may extend from a bottom end of the side wall toward the center side member, and the upper flange may be joined to the bottom surface of the center side member through the fastener.

The skateboard platform may further include a center floor panel disposed on the upper panel.

The center floor panel and the upper panel may form a unitary one-piece structure.

A pair of upper body frame members may be disposed on the pair of center side members, and the center floor panel and the pair of upper body frame members may form a unitary one-piece structure.

The lower panel may have a pair of side edges facing the exterior of the vehicle, and a pair of lower flanges extending from the pair of side edges toward the exterior of the vehicle, respectively, and the pair of lower flanges may be joined to the pair of center side members through the fasteners, respectively.

The lower flange may be joined to a bottom surface of the center side member through the fastener.

A lower sealing member may be interposed between the lower flange and the bottom surface of the center side member.

The skateboard platform may further include a reinforcing plate which overlaps and is stacked on the lower panel, and the reinforcing plate may have a plurality of embossing portions protruding toward the upper panel.

A pair of upper body frame members may be disposed on the pair of center side members, the upper panel may have a pair of upper flanges, the lower panel may have a pair of lower flanges, each upper flange may be joined to a top surface of a corresponding center side member, each lower flange may be joined to a bottom surface of a corresponding center side member, and the center side members may be detachably joined to the upper body frame members so that the battery assembly together with the center side members may be detachably joined to the upper body frame members.

The upper panel may have a pair of upper flanges, the lower panel may have a pair of lower flanges, and each upper flange and each lower flange may be detachably joined to a bottom surface of a corresponding center side member through a fastener so that the battery assembly may be detachably joined to the center side members.

The skateboard platform may further include a first joint connecting a rear end of the front module and a front end of the center module by an interference fit, and a second joint connecting a front end of the rear module and a rear end of the center module by an interference fit.

The first joint may include a first engagement portion provided on the front end of the center module, and a first recess provided in the rear end of the front module, and the first engagement portion may be received in the first recess.

The second joint may include a second engagement portion provided on the front end of the rear module, and a second recess provided in the rear end of the center module, and the second engagement portion may be received in the second recess.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals will be used throughout to designate the same or equivalent elements. In addition, a detailed description of well-known techniques associated with the present disclosure will be omitted in order not to unnecessarily obscure the gist of the present disclosure.

Referring toFIG.1, a vehicle body structure for an electric vehicle according to an exemplary embodiment of the present disclosure may include a skateboard platform10, and one or more upper bodies7and7aselectively assembled onto the skateboard platform10.

The upper bodies7and7amay also be referred to as the “top hat”. One or more upper bodies7and7ahaving various structures and shapes may be selectively assembled to the skateboard platform10so that various upper bodies may share the common skateboard platform10.FIG.1illustrates examples of a sedan-style upper body7and a minivan-style upper body7aselectively assembled to the skateboard platform10. The upper body may be of various body styles, such as a crossover, a sedan, a coupe, and a minivan.

Referring toFIGS.2to4, the skateboard platform10for an electric vehicle according to an exemplary embodiment of the present disclosure may include a skateboard frame11, and a battery assembly12detachably mounted on the skateboard frame11.

The skateboard frame11may be a high-stiffness chassis frame to ensure the overall stiffness of a vehicle body. According to an exemplary embodiment, the skateboard frame11may include a front module20, a center module30, and a rear module40.

The front module20may include a pair of front side members21, a front bumper22disposed on a front end portion of the front module20, and at least one front crossmember23connecting the pair of front side members21. The pair of front side members21may be spaced apart from each other in a width direction of the vehicle, and each front side member21may extend in a longitudinal direction of the vehicle. The front bumper22may be joined to front end portions of the pair of front side members21so that the front end portions of the pair of front side members21may be connected through the front bumper22in the width direction of the vehicle. The front crossmember23may extend in the width direction of the vehicle, and both end portions of the front crossmember23may be joined to rear end portions of the pair of front side members21so that the rear end portions of the pair of front side members21may be connected through the front crossmember23in the width direction of the vehicle.

The center module30may include a pair of center side members31, and a plurality of center crossmembers32a,32b,32c,32d, and32econnecting the pair of center side members31. The pair of center side members31may be spaced apart from each other in the width direction of the vehicle, and each center side member31may extend in the longitudinal direction of the vehicle. Each of the center crossmembers32a,32b,32c,32d, and32emay extend in the width direction of the vehicle, and the plurality of center crossmembers32a,32b,32c,32d, and32emay be spaced apart from each other in the longitudinal direction of the vehicle. Both end portions of each of the center crossmembers32a,32b,32c,32d, and32emay be joined to the pair of center side members31so that the pair of center side members31may be connected through the plurality of center crossmembers32a,32b,32c,32d, and32ein the width direction of the vehicle. The plurality of center crossmembers32a,32b,32c,32d, and32emay include a front-side center crossmember32adisposed on the front of the center module30, a rear-side center crossmember32edisposed on the rear of the center module30, and a plurality of middle-side center crossmembers32b,32c, and32ddisposed between the front-side center crossmember32aand the rear-side center crossmember32e.

The rear module40may include a pair of rear side members41, a rear bumper42disposed on a rear end portion of the rear module40, and a plurality of rear crossmembers43and44connecting the pair of rear side members41. The pair of rear side members41may be spaced apart from each other in the width direction of the vehicle, and each rear side member41may extend in the longitudinal direction of the vehicle. Each of the rear crossmembers43and44may extend in the width direction of the vehicle, and the plurality of rear crossmembers43and44may be spaced apart from each other in the longitudinal direction of the vehicle. Both end portions of the rear crossmember43relatively close to the center module30may be joined to front end portions of the pair of rear side members41so that the front end portions of the pair of rear side members41may be connected through the rear crossmember43in the width direction of the vehicle. Both end portions of the rear crossmember44relatively far from the center module30may be joined to middle portions of the pair of rear side members41so that the middle portions of the pair of rear side members41may be connected through the rear crossmember44in the width direction of the vehicle.

The skateboard platform10for an electric vehicle according to an exemplary embodiment of the present disclosure may include a first joint connecting a rear end portion of the front module20and a front end portion of the center module30by an interference fit, and a second joint connecting a front end portion of the rear module40and a rear end portion of the center module30by an interference fit.

The first joint may include a first engagement portion35provided on a front end of each center side member31of the center module30, and a first recess25provided in the rear end of each front side member21of the front module20. The first engagement portion35may include a plurality of first projections35aprotruding from the front end of the center side member31toward the front of the vehicle and having a cantilevered structure. The plurality of first projections35amay be spaced apart from each other. As the first projections35aof the first engagement portion35are slidably or telescopically received in the first recess25, the front side member21may be temporarily engaged with the front end of the center side member31. Since the plurality of first projections35aprotruding in a cantilevered manner are spaced apart from each other, the plurality of first projections35amay be easily received in the first recess25of the front side member21. In a state in which the first engagement portion35is received in the first recess25, the first engagement portion35and the first recess25may be joined using an adhesive, welding, fasteners (bolts, rivets, etc.) and/or the like, and thus the front module20may be easily and firmly joined to the front of the center module30.

The second joint may include a second engagement portion46provided on the front end of each rear side member41of the rear module40, and a second recess36provided in a rear end of each center side member31of the center module30. The second engagement portion46may include a plurality of second projections46aprotruding from the front end of the rear side member41toward the front of the vehicle and having a cantilevered structure. The plurality of second projections46amay be spaced apart from each other. As the second projections46aof the second engagement portion46are slidably or telescopically received in the second recess36, the rear side member41may be temporarily engaged with the rear end of the center side member31. Since the plurality of second projections46aprotruding in a cantilevered manner are spaced apart from each other, the plurality of second projections46amay be easily received in the second recess36of the center side member31. In a state in which the second engagement portion46is received in the second recess36, the second engagement portion46and the second recess36may be joined using an adhesive, welding, fasteners (bolts, rivets, etc.) and/or the like, and thus the rear module40may be easily and firmly joined to the rear of the center module30.

According to an exemplary embodiment of the present disclosure, the battery assembly12may be directly connected to the skateboard frame11. In particular, the battery assembly12may be detachably connected to the center module30of the skateboard frame11. As the battery assembly12is directly connected to the skateboard frame11ensuring the overall stiffness of the vehicle, the overall stiffness of the vehicle body may be improved and be uniformly distributed through the battery assembly12, and it may be easy to design the vehicle body. In addition, as the battery assembly12is directly connected to the center side members31of the center module30, the number of components may be reduced and the weight and cost may be reduced.

The battery assembly12may include an upper panel51, a lower panel52located below the upper panel51, and a plurality of battery modules53or a plurality of battery cells disposed between the upper panel51and the lower panel52. The upper panel51and the lower panel52may be joined to the center side members31of the center module30through fasteners.

The plurality of battery modules53may be disposed between the upper panel51and the lower panel52. The plurality of battery modules53may be received in a receiving space defined by the upper panel51, the lower panel52, and the pair of center side members31. Referring toFIG.2, the plurality of battery modules53may be disposed between the plurality of center crossmembers32a,32b,32c,32d, and32eso as not to interfere with the plurality of center crossmembers32a,32b,32c,32d, and32e. According to an exemplary embodiment, each battery module53may include the plurality of battery cells, and a predetermined number of battery cells may form the single battery module53.

In addition, the battery assembly12may further include a cooling channel54for preventing the plurality of battery modules53from overheating. The cooling channel54may be disposed to contact the plurality of battery modules53, and the plurality of battery modules53may be maintained at an appropriate temperature by a coolant passing through the cooling channel54.

The upper panel51may serve as an upper cover covering the top of the plurality of battery modules53and a floor of the vehicle body. The upper panel51may have a front edge facing the front of the vehicle, a rear edge facing the rear of the vehicle, and a pair of side edges facing left and right sides of the vehicle.

According to an exemplary embodiment, the upper panel51may have a front wall (not shown) facing the front of the vehicle, a rear wall (not shown) facing the rear of the vehicle, and a pair of side walls51afacing the left and right (exterior) sides of the vehicle. The front wall may extend from the front edge of the upper panel51toward the lower panel52, and the rear wall may extend from the rear edge of the upper panel51toward the lower panel52. The pair of side walls51amay extend from the side edges of the upper panel51toward the lower panel52, respectively.

Each side wall51amay face the exterior of the vehicle and each center side member31of the center module30. The side wall51amay be parallel to an inboard side surface of the center side member31. A pair of upper flanges51bmay extend from the pair of side walls51atoward the exterior of the vehicle, respectively. Each upper flange51bmay extend from a bottom end of the corresponding side wall51atoward the exterior of the vehicle, and the pair of upper flanges51bmay be joined to the center side members31of the center module30through fasteners, respectively. In particular, each upper flange51bmay be joined to the corresponding center side member31through fasteners.FIG.4illustrates the left side wall51aand the left upper flange51blocated on the left side of the upper panel51. Although not shown, the right side wall51aand the right upper flange51bmay also be located on the right side of the upper panel51.

The lower panel52may serve as a lower cover supporting and covering the bottom of the plurality of battery modules53. The lower panel52may have a front edge facing the front of the vehicle, a rear edge facing the rear of the vehicle, and a pair of side edges facing the left and right (exterior) sides of the vehicle. The lower panel52may have a pair of lower flanges52bextending from the pair of side edges toward the exterior of the vehicle, respectively.FIG.4illustrates the left lower flange52blocated on the left side of the lower panel52, but the right lower flange52bmay also be located on the right side of the lower panel52. Each lower flange52bmay extend from each side edge of the lower panel52toward the exterior of the vehicle, and the lower flange52bmay be joined to the corresponding center side member31of the center module30through fasteners.

Referring toFIG.4, the side wall51aof the upper panel51may extend vertically from each side edge of the upper panel51to a top surface of the center side member31, and the upper flange51bmay extend horizontally from the bottom end of the side wall51atoward the center side member31. The upper flange51bmay be aligned with the top surface of the center side member31, and the upper flange51bmay overlap the top surface of the center side member31. The upper flange51band the top surface of the center side member31may be joined through an upper bolt55a. The lower flange52bmay be aligned with a bottom surface of the center side member31, and the lower flange52bmay overlap the bottom surface of the center side member31. The lower flange52band the bottom surface of the center side member31may be joined through a lower bolt56a. The upper flange51band the lower flange52bmay be spaced apart from each other by a gap corresponding to a thickness of the center side member31, and the center side member31may serve as a side wall between the side edge of the upper panel51and the side edge of the lower panel52. An upper sealing member55bmay be interposed between the upper flange51band the top surface of the center side member31, and a lower sealing member56bmay be interposed between the lower flange52band the bottom surface of the center side member31so that the side of the upper panel51and the side of the lower panel52may be joined to the center side member31in a sealed manner.

As described above, the battery assembly12may be connected to the pair of center side members31through the upper flanges51bof the upper panel51and the lower flanges52bof the lower panel52so that the pair of center side members31may serve as the pair of side walls located on left and right sides of the battery assembly12. That is, the battery assembly12may be integrally connected to the center side members31of the center module30.

A front portion of the upper panel51and a front portion of the lower panel52may be joined in a sealed manner, and a rear portion of the upper panel51and a rear portion of the lower panel52may be joined in a sealed manner. For example, the front wall of the upper panel51and the front edge of the lower panel52may be joined in a sealed manner, and the rear wall of the upper panel51and the rear edge of the lower panel52may be joined in a sealed manner. As the upper panel51and the lower panel52are joined to the corresponding center side members31through the sealing members55band56b, the front portion of the upper panel51and the front portion of the lower panel52are joined in the sealed manner, and the rear portion of the upper panel51and the rear portion of the lower panel52are joined in the sealed manner, the battery assembly12may have the receiving space defined by the upper panel51, the lower panel52, and the pair of center side members31, and accordingly the plurality of battery modules53, the cooling channel54, and the like may be received in the receiving space.

Referring toFIG.4, a pair of upper body frame members8may be provided on bottom edges of each of the upper bodies7and7a.FIG.4illustrates the left upper body frame member8located on the left bottom edge of each of the upper bodies7and7a. Although not shown, the right upper body frame member8may be located on the right bottom edge of each of the upper bodies7and7a. Specifically, each upper body frame member8may be a side sill extending along each bottom edge of the upper bodies7and7a. Each of the upper bodies7and7amay have a door opening6in which a door is mounted, and a sealing member9such as a weatherstrip may be mounted along edges of the door opening6.

The skateboard frame11may be joined to the upper body frame member8through a plurality of fasteners14and15, and a bottom surface of the upper body frame member8may be seated on or supported to a top surface of the skateboard frame11. Referring toFIG.4, each center side member31of the skateboard frame11may be joined to the corresponding upper body frame member8through the plurality of fasteners14and15, and the bottom surface of the upper body frame member8may be seated on or supported to the top surface of the center side member31.

According to an exemplary embodiment, the plurality of fasteners14and15may include a plurality of exterior-side bolts14relatively close to the exterior of the vehicle, and a plurality of interior-side bolts15relatively close to the interior of the vehicle when viewed from a transverse cross-section of the upper body frame member8and a transverse cross-section of the center side member31. The plurality of exterior-side bolts14may be spaced apart from each other in the longitudinal direction of the vehicle, and the plurality of interior-side bolts15may be spaced apart from each other in the longitudinal direction of the vehicle. Each exterior-side bolt14may be spaced apart from and be aligned with the corresponding interior-side bolt15along a width axis of the vehicle. In particular, each exterior-side bolt14and the corresponding interior-side bolt15may be symmetrical to each other with respect to a vertical central axis of the upper body frame member8and the center side member31. Thus, the upper body frame member8and the center side member31may be joined by a uniform joining force through the exterior-side bolts14and the corresponding interior-side bolts15.

Referring toFIG.5, the battery assembly12may be integrally connected to the center side member31, and the plurality of exterior-side bolts14and the plurality of interior-side bolts15may be disengaged from the upper body frame member8and the center side member31so that the center side member31may be separated from the upper body frame member8, and the battery assembly12together with the center side member31may be quickly and easily separated from the upper body frame member8. In other words, the battery assembly12may be integrally connected to the center side members31, and the battery assembly12and the center side members31may be quickly and easily separated from the upper body frame members8through the disengagement of the plurality of exterior-side bolts14and the plurality of interior-side bolts15, and thus a swappable battery system may be implemented.

In recent electric vehicles, research and development on the swappable battery system are being carried out, and the swappable battery system is helping to reduce the manufacturer's suggested retail price (MSRP) and taxes by installing a small-capacity battery at the time of vehicle sales, and then replacing it with a large-capacity battery according to customer's needs. In addition, the swappable battery system may reduce the manufacturing cost of the vehicle by removing a charging system such as quick charging equipment, and may allow a discharged battery assembly to be replaced with a charged battery assembly within a relatively short time (within one to two minutes) in an area where infrastructure for quick charging is insufficient.

Referring toFIG.6, the front crossmember23may support the bottom of a front portion of the battery assembly12. Each end portion of the front crossmember23may be joined to a bottom end of the corresponding front side member21, and accordingly a bottom surface of the front crossmember23may be aligned with a bottom surface of the front side member21. That is, the bottom surface of the front crossmember23may be flush with the bottom surface of the front side member21. In particular, the front portion of the lower panel52of the battery assembly12may be seated on the front crossmember23, and thus the front portion of the battery assembly12may be stably supported to the front crossmember23.

Referring toFIG.7, at least one rear crossmember43of the plurality of rear crossmembers, which is adjacent to the center module30, may support the bottom of a rear portion of the battery assembly12. Each end portion of the rear crossmember43may be joined to a bottom end of the corresponding rear side member41, and accordingly a bottom surface of the rear crossmember43may be aligned with a bottom surface of the rear side member41. That is, the bottom surface of the rear crossmember43may be flush with the bottom surface of the rear side member41. The rear portion of the lower panel52of the battery assembly12may be seated on the rear crossmember43, and thus the rear portion of the battery assembly12may be stably supported to the rear crossmember43.

Referring toFIG.8, the skateboard platform10for an electric vehicle according to an exemplary embodiment of the present disclosure may further include a center floor panel57disposed on the upper panel51of the battery assembly12. As the center floor panel57overlaps and is stacked on the upper panel51, the center floor panel57may increase the stiffness and strength of the vehicle body and/or the battery assembly12. The center floor panel57may have a pair of side walls57afacing the exterior of the vehicle, and a pair of flanges57bextending from the pair of side walls57atoward the exterior of the vehicle.

The center floor panel57may have a front edge facing the front of the vehicle, a rear edge facing the rear of the vehicle, and a pair of side edges facing the left and right (exterior) sides of the vehicle. Each side wall57amay extend from the side edge of the center floor panel57toward the lower panel52, and each flange57bmay extend from a bottom end of the corresponding side wall57atoward the exterior of the vehicle. The side wall57aof the center floor panel57may overlap the side wall51aof the upper panel51, and the side wall57aof the center floor panel57may be parallel to the side wall51aof the upper panel51. The flange57bof the center floor panel57may be aligned with the top surface of the center side member31. The flange57bof the center floor panel57may overlap the upper flange51bof the upper panel51, and the flange57bof the center floor panel57may be parallel to the upper flange51bof the upper panel51. The flange57bof the center floor panel57together with the upper flange51bof the upper panel51may be joined to the top surface of the center side member31through the upper bolt55a. According to the exemplary embodiment illustrated inFIG.8, the center floor panel57together with the battery assembly12may be integrally connected to the center side members31of the skateboard frame11.

According to an exemplary embodiment, the center floor panel57and the upper panel51may form a unitary one-piece structure, and thus the center floor panel57and the upper panel51may form a double plate structure in which they overlap each other.

According to another exemplary embodiment, the center floor panel57and the upper panel51may be provided as separate pieces, and thus the center floor panel57and the upper panel51may be joined together using fasteners, welding, and/or the like.

Referring toFIGS.4and8, the center side member31may have a mounting surface31arecessed from the top surface thereof toward the bottom surface thereof, and the upper flange51bof the upper panel51and/or the flange57bof the center floor panel57may be joined to the mounting surface31athrough the upper bolt55a.

Referring toFIG.8, the battery assembly12may further include a reinforcing plate58disposed on the lower panel52. As the reinforcing plate58overlaps and is stacked on the lower panel52, the reinforcing plate58may increase the stiffness and strength of the lower panel52. The reinforcing plate58may have a plurality of embossing portions58aprotruding toward the upper panel51, and the reinforcing plate58may further increase the stiffness and strength of the lower panel52. The reinforcing plate58may have a pair of flanges58bextending from both side edges thereof toward the exterior of the vehicle. Each flange58bof the reinforcing plate58may overlap the lower flange52bof the lower panel52, and the flange58bof the reinforcing plate58may be parallel to the lower flange52bof the lower panel52. The flange58bof the reinforcing plate58together with the lower flange52bof the lower panel52may be joined to the bottom surface of the center side member31through the lower bolt56a. The lower sealing member56bmay be interposed between the flange58bof the reinforcing plate58and the bottom surface of the center side member31.

According to an exemplary embodiment, the reinforcing plate58and the lower panel52may form a unitary one-piece structure, and thus the reinforcing plate58and the lower panel52may form a double plate structure in which they overlap each other.

According to another exemplary embodiment, the reinforcing plate58and the lower panel52may be provided as separate pieces, and the reinforcing plate58and the lower panel52may be joined together using fasteners, welding, and/or the like.

Referring toFIG.4, the upper panel51may be a flat plate, and the upper panel51may be flush with a top surface of the upper body frame member8or a top surface of the sealing member9. Thus, a flat floor of the vehicle may be easily formed.

Referring toFIG.4, the lower panel52may be a flat plate, and the lower panel52may be slightly lower than or be flush with the bottom surface of the center side member31of the center module30. Thus, even if the lower portion of the battery assembly12is exposed to the outside, the flat lower panel52may prevent deterioration of the appearance of the vehicle.

FIG.9illustrates a skateboard platform for an electric vehicle according to another exemplary embodiment of the present disclosure. According to the exemplary embodiment illustrated inFIG.9, each side wall51cof the upper panel51may extend from each side edge of the upper panel51to the bottom surface of the center side member31, and the side wall51cof the upper panel51may be parallel to an inboard side surface of the upper body frame member8and the inboard side surface of the center side member31. An upper flange51dmay extend horizontally from a bottom end of the side wall51ctoward the exterior of the vehicle. The upper flange51dmay be aligned with the bottom surface of the center side member31, and the upper flange51dtogether with the lower flange52bof the lower panel52may overlap the bottom surface of the center side member31. The upper flange51dand the lower flange52bmay be joined to the bottom surface of the center side member31through a bolt55c. A sealing member55dmay be interposed between the upper flange51dand the lower flange52bso that the upper flange51dof the upper panel51and the lower flange52bof the lower panel52may be joined in a sealed manner.

FIG.10illustrates a skateboard platform for an electric vehicle according to another exemplary embodiment of the present disclosure. Referring toFIG.10, the center floor panel57may be disposed on the upper panel51, and the center floor panel57may be integrally connected to the upper body frame member8. That is, since the center floor panel57is connected to the upper body frame member8instead of being connected to the battery assembly12, the upper panel51of the battery assembly12may only serve as an upper cover covering the top of the plurality of battery modules53, and the center floor panel57may only serve as the floor of the vehicle body.

According to an exemplary embodiment, the center floor panel57and the upper body frame members8may form a unitary one-piece structure. The center floor panel57may have a pair of side walls57cprovided on both side edges thereof, and each side wall57cmay be inclined at a predetermined angle with respect to a vertical axis of the upper body frame member8. A bottom end of the side wall57cmay be integrally connected to the upper body frame member8.

According to another exemplary embodiment, the center floor panel57and the upper body frame member8may be provided as separate pieces, and each flange of the center floor panel57may be joined to the top surface of the upper body frame member8using fasteners, welding, and/or the like. The flange of the center floor panel57may extend from the bottom end of the side wall57ctoward the exterior of the vehicle. The flange of the center floor panel57may be aligned with the top surface of the upper body frame member8, and the flange of the center floor panel57may overlap the top surface of the upper body frame member8.

According to the exemplary embodiments illustrated inFIGS.9and10, as the bolt55cis disengaged from the center side member31, the upper panel51and the lower panel52of the battery assembly12may be easily and quickly separated from the center side member31. Since the battery assembly12is easily and quickly separated from the center side member31through the disengagement of the bolt55c, a swappable battery system may be implemented.

As set forth above, the skateboard platform for an electric vehicle, according to exemplary embodiments of the present disclosure, may allow the battery assembly to be integrally connected to the center module of the skateboard frame, thereby increasing the overall stiffness of the vehicle body which is uniformly distributed through the battery assembly, and reducing the overall number of components which results in reduced weight and cost.

In addition, as the battery assembly is integrally connected to the center module of the skateboard frame, the standardization of skateboard platforms for common use may be easily achieved. The skateboard platform according to exemplary embodiments of the present disclosure may easily respond to design changes in vehicle specifications/dimensions (full width, wheelbase, etc.). For example, the size, structure, and shape of the skateboard frame and the battery assembly may be easily variable by the design changes in the vehicle specifications/dimensions (full width, wheelbase, etc.).

In particular, as the battery assembly is connected between the pair of center side members, which are the side structural members of the vehicle body, through the fasteners, the pair of center side members may serve as both side walls of the battery assembly so that the lateral stiffness and lateral strength of the battery assembly may be sufficiently secured by the pair of center side members. That is, the pair of center side members may support a lateral load of the vehicle body and a lateral load of the battery assembly together. Since a separate reinforcement for increasing the stiffness and strength of the battery assembly is not required, the structure of the battery assembly may be simplified, which is advantageous to protection of the battery modules. The battery assembly may be stably protected by the center side members, namely the structural members of the vehicle, and thus crashworthiness of the battery assembly may be improved, and the weight and cost of the battery assembly may be reduced.

The battery assembly may be easily and quickly separated from the center side members so that the swappable battery system may be easily implemented.

In addition, the battery assembly may be integrally connected to the skateboard frame through the center side members, and the skateboard frame may be quickly and easily separated from the upper body frame members, and thus the swappable battery system may be easily implemented, leading to the implementation of a BaaS (battery as a service) business model which allows swapping of battery packs of various capacities. By facilitating the implementation of the swappable battery system, the total cost of ownership of electric vehicles may be minimized in areas where quick charging equipment and charging infrastructure are not established.