JP2012066773A - Floor structure for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floor structure for an electric vehicle, which effectively protects a battery mounted to the vehicle especially when an impact load is exerted on a side surface of the vehicle.SOLUTION: The floor structure for the electric vehicle, which is formed of a fiber reinforced resin, includes at least: a framework including a stiffener extended along an outer edge thereof and a rib extended in a vehicle width direction; and a panel extended in a non-framed part. In the floor structure for an electric vehicle, a mounting part of a battery holding member is provided in the panel of the floor structure.

Description

  The present invention relates to a floor structure for an electric vehicle made of fiber reinforced resin, and more particularly to an electric vehicle floor structure that can effectively protect a battery mounted when an impact load is applied from the side of the vehicle. . The electric vehicle in the present invention is a concept that includes all vehicles equipped with a battery that supplies power to a driving motor, from a normal electric vehicle to a hybrid vehicle and a fuel cell vehicle.

  An electric vehicle that uses an electric motor as a power source for driving a vehicle has a low carbon dioxide emission as a whole, and is attracting attention as a vehicle adapted to the global environment. In particular, the concept of LCA (Life Cycle Assessment) has been adopted in recent years, and the reduction of carbon dioxide emissions throughout the life from the vehicle manufacturing stage including materials to the use of the vehicle to the scrapped vehicle is being evaluated. In an electric vehicle, since a motor for driving a vehicle has a high degree of freedom in the vehicle mounting position, the degree of freedom in designing a vehicle body is greatly improved. For this reason, the shape and the degree of freedom of the structure of the skeleton structure for constituting the passenger compartment and the floor portion are greatly increased. In addition, it is essential for an electric vehicle to be equipped with a battery for supplying power to the motor, but the mounting structure of this battery is considered to have a relatively high degree of freedom.

  In the case of a metal body structure, the battery is usually mounted on the lower part (lower surface side) of the floor structure constituting the floor, but when an impact load is applied from the side of the vehicle, such as a side collision, for example. If the side of the vehicle body is greatly deformed and a collision vehicle or the like enters the vehicle body, there is a risk that the case containing the battery or the battery itself may be damaged, and there is a risk of leakage or fire from the battery. In particular, in the case of a metal body structure, a cross-beam-like skeleton is formed in the vehicle longitudinal direction and the vehicle width direction, and a battery holding member is often attached to the skeleton of the skeleton. Since it becomes a transmission path and an impact load at the time of a side collision or the like is directly transmitted to the battery case or the battery, it is more difficult to prevent the battery from being damaged.

  In the prior art, the mounting portion and the case itself are deformed so that no load is applied to the battery even if the vehicle body is deformed, and the structure is such that the load is not easily applied to the battery case or the like (for example, Patent Documents 1 to 3). 3). However, in the case of a metal body structure, it is often necessary to be a structure consisting of a frame consisting of beams extending vertically and horizontally and a sheet metal, so a battery case containing a relatively heavy battery is installed. In order to do this, it is usually attached to the frame part, so it is difficult to appropriately prevent the transmission of the impact load accompanying the side collision as described above.

  On the other hand, as basic required specifications for automobiles, the configuration to ensure the safety of passengers in the event of a collision, the weight reduction of the vehicle body for the improvement of fuel consumption, excellent mass productivity and reduction of manufacturing costs, etc. Is required. As a configuration for ensuring the safety of the occupant in the event of a collision including the weight reduction of the vehicle body, for example, a structure in which the vehicle body skeleton portion is formed of a fiber reinforced composite material has been proposed (for example, Patent Document 4). In the structure disclosed in Patent Document 4, a vehicle body skeleton part and a vehicle compartment part constituting the lower part of the vehicle body are formed independently, and the vehicle body skeleton part is formed of fiber reinforced resin, and impact load absorbing performance is formed in that part. It is made to have.

  However, in the structure disclosed in Patent Document 4, a structural device is added to the structure of the vehicle body skeleton part itself located in the lower part of the passenger compartment so as to easily absorb the impact load. No consideration is given to the reduction of the impact load on the battery case or the battery when a structure to which the battery case is attached is assumed. In other words, for occupants in the room, safety is ensured by absorbing impact load by the vehicle body skeleton part, but from the standpoint of preventing damage to the on-board battery in the electric vehicle, a structure that has been devised and considered It can not be said.

Japanese Patent Laying-Open No. 2005-297861 JP 2008-100585 A JP 2008-226610 A JP 2010-23706 A

  Therefore, the object of the present invention is to focus on battery protection in an electric vehicle and consider the high degree of freedom of design in the electric vehicle, and particularly to install a battery mounted when an impact load is applied from the side of the vehicle. An object of the present invention is to provide an electric vehicle floor structure that can be effectively protected.

  In order to solve the above-described problem, the floor structure for an electric vehicle according to the present invention includes at least a stiffener extending along the outer edge, a skeleton portion including ribs extending in the vehicle width direction, and a panel portion extending in the non-skeleton portion. A floor structure for an electric vehicle made of a fiber reinforced resin, wherein the panel portion of the floor structure is provided with an attachment portion for a battery holding member.

  In such a floor structure for an electric vehicle according to the present invention, the floor structure can be easily integrally formed and is a fiber-reinforced resin floor structure having a high degree of design freedom. This floor structure made of fiber reinforced resin is configured to have a structure having at least a stiffener extending along the outer edge, a skeleton portion including ribs extending in the vehicle width direction, and a panel portion extending to the non-skeleton portion. The skeletal part gives sufficiently high rigidity and strength to the entire floor structure, and the deformation of the structure when an impact load is applied is suppressed, which contributes to ensuring the safety of passengers. it can. And by having the panel part which consists of a thin board etc. made from a fiber reinforced resin in the non-skeleton part which is parts other than this skeleton part, the form required as the whole floor structure is arranged. The skeleton part is the main path for load transmission when impact load is applied, especially when impact load is applied at the time of side collision, etc., but the panel part has a structure that easily buckles. Therefore, the load transmission path is not substantially formed. Since the mounting portion of the battery holding member (for example, battery case) is provided on the panel portion having such characteristics, when an impact load or the like is applied to the floor structure during a side collision, the impact load is substantially reduced. Therefore, the battery case and the battery are not properly damaged due to the transmission of the impact load.

  In the electric vehicle floor structure according to the present invention, the stiffener extends over the entire edge of the floor structure, the rib extends over the entire width of the floor structure in the vehicle width direction, and the panel. It is preferable to adopt a structure in which the part spreads to a part surrounded by the skeleton part. By configuring in this way, it is possible to realize a structure in which an impact load or the like is not easily transmitted to the panel portion while having high rigidity and strength as the entire skeleton portion of the floor structure. In addition, the panel part can also be made into the structure which is not partially enclosed by the frame | skeleton part as needed.

  Further, a plurality of the mounting portions are provided, and only one of the mounting portions is provided in the skeleton portion, and the other mounting portion is provided in the panel portion. Or it can also be set as the structure where the said attachment part is provided with two or more and all are provided in the panel part. In the former structure, the mounting part provided in the skeleton part can secure the strength for fixing the position of the floor structure during normal running vibration, etc., and when an impact load such as a side collision occurs, the floor structure With respect to the mounting form of the battery holding member with respect to the panel part, by allowing the rotational movement around the attachment part to the skeleton part while allowing the freedom of relative movement in the attachment part to the panel part, or to the skeleton part By allowing the attachment portion to break, transmission of the transmission load in the skeleton portion to the battery holding member side via the attachment portion can be avoided, and damage to the battery case and the battery can be prevented appropriately. . In the latter structure, all the attachment parts are separated from the load transmission path formed by the skeleton part, and it is possible to appropriately prevent the battery case and the battery from being damaged.

  Further, in the electric vehicle floor structure according to the present invention, the mounting portion may be formed integrally with the floor structure, and the mounting portion is configured separately from the floor structure. In addition, the mounting member constituting the separate mounting portion may be joined to the floor structure by mechanical connection, fusion, adhesion, or the like. In consideration of ease of molding, simplification of the manufacturing process, reduction of manufacturing cost, and the like, it may be determined which form should be adopted.

  Furthermore, in the present invention, at least a part of the battery holding member may be formed integrally with the mounting portion. For example, the mounting portion is configured separately from the floor structure, and at least a part of the battery holding member is integrally formed therewith, or at least a part of the mounting portion and the battery holding member is It can be formed integrally with the floor structure. With such an integrated structure, it is possible to facilitate manufacturing and shorten the manufacturing and assembly time.

  In the floor structure for an electric vehicle according to the present invention, it is preferable that the mounting portion is provided at a position of a buckling deformation node in the panel portion. Thus, if the buckle deformation is provided at the position of the node, even if deformation such as swell occurs due to the load received by the entire floor structure on the surrounding panel part, the displacement of the mounting part itself is Since it is suppressed, rapid displacement of the battery holding member via the mounting portion is suppressed, and the battery case and the battery are more appropriately protected.

  Moreover, in the floor structure for electric vehicles which concerns on this invention, the structure by which the said attaching part is comprised by the form of the at least 2 item | strip extended in the vehicle front-back direction is also a preferable form. That is, since the battery case is often relatively large and relatively heavy, the battery case is attached through the attachment portion extending in such two lines, thereby providing a more stable holding form (for example, a suspended form). It becomes possible.

  Furthermore, in the electric vehicle floor structure according to the present invention, the mounting portion (whether formed integrally with the panel portion or formed separately), the panel portion. It can be set as the structure currently formed in the protrusion part which protruded locally from. If the attachment portion is formed in such a protruding portion, the attachment of the battery holding member is facilitated appropriately. However, in order to facilitate manufacture and molding, the mounting portion is formed on the planar portion of the panel portion itself (that is, without surrounding projections, It may be a structure formed on the same surface as the portion.

  In the electric vehicle floor structure according to the present invention, the cross-sectional shape of the stiffener or rib is not particularly limited, and various cross-sectional shapes can be adopted. For example, various cross-sectional shapes such as an I shape, a T shape, an L shape, an inverted L shape, a Z shape, a C shape, and a hat shape can be employed in addition to a simple standing wall shape.

  Moreover, the electric vehicle floor structure according to the present invention is configured as a structure that constitutes a floor portion of an automobile, and also has a function as a structure that constitutes a skeleton of a passenger compartment. It is also possible to In this case, for example, it may be formed into a monocoque structure that constitutes the passenger compartment and the floor with a fiber reinforced resin.

  Furthermore, in the present invention, the reinforcing fiber of the fiber reinforced resin used for the floor structure is not particularly limited, and carbon fiber, glass fiber, aramid fiber, etc. can be used, and a hybrid structure in which these reinforcing fibers are combined. Adoption is also possible. Further, the matrix resin of the fiber reinforced resin is not particularly limited, and either a thermosetting resin or a thermoplastic resin can be used. A typical example of the thermosetting resin that can be used is an epoxy resin. For molding in the case of using a thermosetting resin, it is possible to apply a molding method such as RTM (Resin Transfer Molding) or press molding using a prepreg. In the case of a thermoplastic resin, injection molding can be applied in addition to the above molding method. Usable thermoplastic resins include, for example, polyamide (nylon 6, nylon 66, etc.), polyolefin (polyethylene, polypropylene, etc.), polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate, polyamideimide, polyphenylene sulfide, polyphenylene oxide. Polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polystyrene, ABS, liquid crystal polyester, a copolymer of acrylonitrile and styrene, and the like can be used. A mixture of these may also be used. Moreover, what was copolymerized like the copolymer nylon of nylon 6 and nylon 66 may be used. Furthermore, depending on the required properties of the molded product to be obtained, flame retardants, weather resistance improvers, other antioxidants, heat stabilizers, UV absorbers, plasticizers, lubricants, colorants, compatibilizers, conductive fillers, etc. It can be added.

  Thus, according to the floor structure for an electric vehicle according to the present invention, a transmission path for impact load and the like is provided by providing the mounting portion on the panel portion while ensuring the necessary rigidity and strength of the floor structure at the skeleton portion. Thus, the battery mounting portion can be appropriately removed, and the battery mounted when an impact load or the like is applied from the side of the vehicle can be effectively protected. As a result, the occurrence of unforeseen situations such as electric leakage and fire can be prevented. In addition, by configuring the floor structure with a fiber reinforced resin, it is possible to manufacture a floor structure for an electric vehicle that is excellent in lightness and mass productivity at low cost.

It is the partial longitudinal cross-sectional view (B) seen from the angle different from the partial longitudinal cross-sectional view (A) and figure (A) of an electric vehicle which have the floor structure concerning one embodiment of this invention. It is the perspective view (A) of the floor structure of FIG. 1, and the bottom view (B) which concerns on A arrow of figure (A). It is a bottom view of the floor structure which shows the example of the installation position of the attaching part different from FIG. 2 (B). It is an expanded sectional view showing an example of structure of an attaching part seen along a BB line of Drawing 2 (B). It is sectional drawing which shows the structural example of the attaching part different from FIG. They are a bottom view (A) of a floor structure at the time of providing an attaching part in a node of buckling deformation of a panel part, and a schematic expanded sectional view (B) which meets a CC line of Drawing (A). It is a bottom view of the floor structure which shows the example which provided the attaching part with the form of 2 items.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an electric vehicle provided with a floor structure for an electric vehicle according to an embodiment of the present invention, and FIG. 2 shows the floor structure. The electric vehicle 100 has a floor structure 1 made of fiber reinforced resin, and the floor structure 1 includes at least a stiffener 2 extending along an outer edge thereof and a skeleton portion 4 including ribs 3 extending in the vehicle width direction. And a panel portion 5 extending to a non-skeleton portion other than the skeleton portion 4. An attachment portion 7 for attaching a battery holding member 6 (for example, a battery case) containing an appropriate number of batteries (not shown) inside the panel portion 5 of the floor structure 1 to the lower surface side of the floor structure 1. Are provided at a plurality of locations as shown in FIG. In this embodiment, the stiffener 2 extends over the entire edge of the floor structure 1, the rib 3 extends over the entire width of the floor structure 1 in the vehicle width direction XX, and the panel portion 5 extends to the skeleton portion 4. It extends to the enclosed part. Moreover, in this embodiment, the floor structure 1 is configured as a structure for a floor portion of a vehicle and a structure for a front portion and a rear portion of a passenger compartment, and is configured as a monocoque structure made of fiber reinforced resin. Yes. This monocoque structure made of fiber reinforced resin can be integrally molded as a whole, or can be formed into an integral structure in which divided structures are joined.

  As described above, the floor structure 1 made of fiber reinforced resin is provided with the skeleton portion 4 including the stiffener 2 extending along the outer edge and the rib 3 extending in the vehicle width direction, so that the floor structure 1 as a whole is sufficiently high. Rigidity and strength are ensured, and deformation of the entire structure 1 when an impact load such as a collision is applied is suppressed, which can contribute to ensuring the safety of the passenger. That is, the skeleton 4 serves as a main transmission path of a load such as an impact load, exhibits a high resistance against the load to be transmitted, and suppresses the deformation of the entire structure 1. A panel portion 5 made of a thin plate made of fiber reinforced resin or the like is located in a non-skeleton portion other than the skeleton portion 4, and a battery holding member 6 (for example, a battery case) is attached to the panel portion 5. Since the portion 7 is provided, the mounting portion 7 is disposed at a position substantially deviated from the load transmission path, and direct transmission of impact load or the like is avoided, and the battery case is transmitted by transmission of impact load or the like. And damage to the battery is properly prevented. In particular, the panel portion 5 has a thinner and less rigid thin plate structure than the skeleton portion 4 formed of the stiffener 2 and the rib 3, so that the panel portion 5 is easily buckled as needed, and a large load is not transmitted to the mounting portion 7. . As a result, as described above, damage to the battery case and the battery due to transmission of an impact load or the like is appropriately prevented.

  Further, FIG. 2B shows a case where all the mounting portions 7 are provided on any of the panel portions 5, but as shown in FIG. 3, one of the plurality of mounting portions 7 is attached. If only the portion 7 a is provided on the skeleton portion 4 (in the illustrated example, on the rib 3 extending in the vehicle front-rear direction) and the other attachment portion 7 is provided on the panel portion 5, the skeleton portion 4 is provided. The attached mounting portion 7a can more appropriately secure the strength for fixing the position of the floor structure 1 at the time of normal traveling vibration and the like, and a battery holding member for the floor structure 1 when an impact load is generated at the time of a side collision or the like. 6, while allowing a degree of freedom of relative movement in the attachment portion 7 to the panel portion 5, it is possible to allow a rotational movement around the attachment portion 7 a to the skeleton portion 4, or to the skeleton portion 4. By allowing the mounting portion 7a to break, the entire floor structure 1 The necessary degree of freedom of the relative displacement can be secured, thereby achieving the necessary position fixing of the floor structure 1 at the normal time, while the battery holding member 6 side through the mounting portion when a large impact load or the like is applied. The transmission of the load to the battery can be avoided, and damage to the battery case and the battery can be prevented appropriately.

  As a specific example of the mounting portion structure in the present invention, the mounting portion 7 is integrated with the floor structure 1 as shown in FIGS. 4 and 5 as a cross-sectional form along the line BB in FIG. It can also be set as the structure currently shape | molded (FIG. 4), the attachment part 7 is comprised separately from the floor structure 1, and the attachment member 8 which comprises this separate attachment part 7 is a floor structure. 1 can also be used (FIG. 5). As shown in FIGS. 4 and 5, the mounting portion 7 is formed in a protruding portion shape in which the mounting portion 7 locally protrudes from the floor structure 1 (particularly from the panel portion 5). It can be set as a structure. If it forms in the attaching part 7 formed in such a protrusion part shape, the attachment operation of the battery holding member 6 via the fastening means 9 grade | etc., Will be facilitated.

  Further, as shown in FIG. 6, the attachment portion 7 is preferably provided at the position of the buckling deformation node 10 in the panel portion 5. Thus, if it is provided at the position of the buckling deformation joint 10, even if the deformation 11 such as swell occurs in the surrounding panel portion 5 due to the load received by the entire floor structure 1, the mounting portion Since the displacement of 7 itself is suppressed, the sudden displacement of the battery holding member 6 via the mounting portion 7 is suppressed, and the battery case and the battery are more appropriately protected.

  Furthermore, as described above, in the electric vehicle floor structure according to the present invention, a structure in which the mounting portion is configured in at least two strips extending in the vehicle front-rear direction can also be employed. Although an example of such a form is shown in FIG. 7, two mounting portions 12 can be provided in the vehicle front-rear direction YY across the panel portions 5.

  The floor structure for an electric vehicle according to the present invention can be applied to all electric vehicles equipped with a battery that supplies power to a traveling motor.

DESCRIPTION OF SYMBOLS 1 Floor structure 2 Stiffener 3 Rib 4 Skeletal part 5 Panel part 6 Battery holding member 7, 7a Attachment part 8 Attachment member 9 Fastening means 10 Buckling deformation node 11 Deformation 12 Two attachment parts 100 Electric vehicle

Claims (11)

  A floor structure for an electric vehicle made of a fiber reinforced resin, having at least a skeleton portion including a stiffener extending along an outer edge and a rib extending in a vehicle width direction, and a panel portion extending in a non-skeleton portion, the floor structure A mounting structure for a battery holding member is provided on the panel portion of the electric vehicle floor structure.   The stiffener extends over the entire edge of the floor structure, the rib extends over the entire width of the floor structure in the vehicle width direction, and the panel portion extends to a portion surrounded by the skeleton portion. The floor structure for electric vehicles according to claim 1.   The electricity according to claim 1 or 2, wherein a plurality of the attachment portions are provided, only one of the attachment portions is provided in the skeleton portion, and the other attachment portion is provided in the panel portion. Automotive floor structure.   The floor structure for an electric vehicle according to claim 1, wherein a plurality of the attachment portions are provided, and all of the attachment portions are provided on the panel portion.   The floor structure for an electric vehicle according to any one of claims 1 to 4, wherein the attachment portion is formed integrally with the floor structure.   The said attachment part is comprised separately from the said floor structure, The attachment member which comprises this separate attachment part is joined to the said floor structure. Floor structure for electric vehicles.   The floor structure for an electric vehicle according to any one of claims 1 to 6, wherein at least a part of the battery holding member is formed integrally with the mounting portion.   The floor structure for an electric vehicle according to any one of claims 1 to 7, wherein the attachment portion is provided at a position of a buckling deformation node in the panel portion.   The floor structure for an electric vehicle according to any one of claims 1 to 8, wherein the attachment portion is configured in at least two strips extending in a vehicle longitudinal direction.   The floor structure for an electric vehicle according to any one of claims 1 to 9, wherein the mounting portion is formed in a protruding portion that locally protrudes from the panel portion.   The floor structure for an electric vehicle according to any one of claims 1 to 9, wherein the attachment portion is formed on the planar portion itself of the panel portion.

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