Patent ID: 12233947

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, directions of forward, rearward, upward, downward, rightward, and leftward mean directions with respect to a direction in which a vehicle proceeds forward unless otherwise specified. In appropriate places in the drawings, an arrow FR that indicates a vehicle forward direction, an arrow UP that indicates a vehicle upward direction, and an arrow LH that indicates a vehicle leftward direction are shown.

FIG.1is a perspective view showing a vehicle body rear portion of a vehicle1according to the present embodiment viewed from a forward, leftward, and diagonally upward direction.FIG.2is a cross-sectional view along a II-II line ofFIG.1.

Reference numeral10in the drawing indicates a front floor panel arranged below an occupant room. Reference numeral11indicates a rear floor panel arranged at a rearward position of a front floor panel10. The rear floor panel11constitutes a floor surface at a rearward position (for example, a load room) of the occupant room. A side sill12which is a skeleton frame that extends along a vehicle body forward-rearward direction is arranged on both right and left sides on a lower portion side of the occupant room. The front floor panel10is provided on right and left side sills12. A lower surface side of the front floor panel10is supported by a plurality of floor frames (not shown). A rear side frame30which is a skeleton frame that extends to a vehicle body rearward side is joined to the inside in a vehicle width direction of a rear region of each of the side sills12on right and left sides of the vehicle body. The rear floor panel11is provided on right and left rear side frames30.

The front floor panel10, the rear floor panel11, the side sill12, and the rear side frame30described above, and main configuration members of the vehicle body rear portion described later are mainly formed of a metal material.

A floor tunnel15that extends along the vehicle body forward-rearward direction is provided on a middle in the vehicle width direction of the front floor panel10. The floor tunnel15is formed in a substantially U-shape in a cross-section that opens downward. The substantially U-shape in a cross-section extends along the vehicle body forward-rearward direction. The floor tunnel15projects upward relative to a substantially flat base wall (a bottom wall that extends substantially horizontally) of the front floor panel10. A tunnel ridge line31that extends along the vehicle body forward-rearward direction is formed on right and left sides of an upper end portion of the floor tunnel15. The tunnel ridge line31is a ridge line formed of a bend angle portion between an upper wall of the floor tunnel15and each of right and left side walls.

An upper surface of the rear floor panel11is set to be higher than an upper surface of the front floor panel10. A unit protection cover16made of a metal is arranged between the front floor panel10and the rear floor panel11. A front edge portion of the rear floor panel11and a rear edge portion of the front floor panel10are welded and fixed to the unit protection cover16.

A rear cross panel35having a substantially L shape in a cross-section that intersects the vehicle width direction is joined to a lower surface of the rear floor panel11at a position that is separated rearward by a predetermined distance from a joint portion with the unit protection cover16on the front end side. The rear cross panel35constitutes a closed cross-section that extends along the vehicle width direction together with the rear floor panel11. The closed cross-section portion formed of the rear floor panel11and the rear cross panel35constitutes a rear cross member40that extends along the vehicle width direction at a rearward position of the unit protection cover16. An outer end portion in the vehicle width direction of the rear cross member40is connected to a corresponding rear side frame30on the right and left sides.

As shown inFIG.2, a battery unit17which is protection target unit is arranged below the unit protection cover16. Although detailed description in the drawings is omitted, the battery unit17includes a battery module constituted by laminating a plurality of batteries and a control unit that controls discharging and charging between the battery module and a motor for driving the vehicle.

InFIG.2, although description in the drawings is omitted, a base plate which is a unit accommodation portion is provided between a front portion of the rear floor panel11and a rear end portion of the front floor panel10. The battery unit17is provided on the base plate, and an upper side of the battery unit17is covered by the unit protection cover16. In the present embodiment, a front edge portion of the rear floor panel11and a rear edge portion of the front floor panel10are connected via the base plate and the unit protection cover16.

In the present embodiment, the battery unit17is arranged below the unit protection cover16; however, in the case of a vehicle on which an engine is provided, a fuel tank may be arranged at the same location (a lower position of the unit protection cover16). In this case, the fuel tank and an accompanying component of the fuel tank are the protection target unit.

As shown inFIG.2, the unit protection cover16includes: a rear flange16rthat is joined to a front end portion of the rear floor panel11: an upper wall16uthat is inclined upward and forward from the rear flange16rand then extends forward substantially horizontally; and a front wall16fthat is bent and extends downward from a front end portion of the upper wall16u.

As shown inFIG.1, the upper wall16uof the unit protection cover16is higher than an upper surface of the floor tunnel15. Accordingly, the unit protection cover16rises upward relative to the upper surface of the floor tunnel15.

A side inclination portion16uithat extends to be inclined downward and outward in the vehicle width direction and a joint flange16ufthat extends substantially horizontally outward in the vehicle width direction from a lower end of the side inclination portion16uiare formed in an outer region in the vehicle width direction of the upper wall16uof the unit protection cover16. The joint flange16ufis formed so as to continue to a rear flange11rof the unit protection cover16. Each of right and left joint flanges16ufis overlapped with a corresponding rear side frame30on right and left sides and is welded and fixed to the rear side frame30in that state.

As shown inFIG.2, the front wall16fof the unit protection cover16includes: a front wall main body wall16fathat extends downward from a front end portion of the upper wall16u; and a step wall16fsthat is bent and extends forward from a lower end of the front wall main body wall16fa.

A protrusion portion18having substantially the same width as an upper end portion of the floor tunnel15is formed on a middle in the vehicle width direction of the front wall16fand the upper wall16uof the unit protection cover16. The protrusion portion18includes: an upper wall protrusion region18uthat is formed on the upper wall16uof the unit protection cover16; and a front wall protrusion region18fthat is formed on the front wall16fof the unit protection cover16. Both the upper wall protrusion region18uand the front wall protrusion region18fhave a substantially flat top wall18ut,18ftand right and left side walls18us,18fs. The right and left side walls18usof the upper wall protrusion region18uprotrude upward. The right and left side walls18fsof the front wall protrusion region18fprotrude in a forward upward direction of the vehicle. Bend corner portions between the right and left side walls18us,18fsand the top walls18ut,18ftof the upper wall protrusion region18uand the front wall protrusion region18fcontinue to the right and left tunnel ridge lines31of the floor tunnel15in the vehicle body forward-rearward direction. Each of the bend corner portions constitutes an extension ridge line32A that extends continuously from each of the right and left tunnel ridge lines31of the floor tunnel15in a vehicle body rearward direction.

The right and left side walls18usof the upper wall protrusion region18uextend to be inclined outward in the vehicle width direction in a downward direction from the corresponding right and left extension ridge lines32A. The right and left side walls18fsof the front wall protrusion region18fare inclined outward in the vehicle width direction in a rearward downward direction from the corresponding right and left extension ridge lines32A.

A protrusion portion19that is similar to the protrusion portion18of the unit protection cover16is formed on a middle in the vehicle width direction of the rear floor panel11so as to continue to the protrusion portion18of the unit protection cover16. The protrusion portion19of the rear floor panel11is formed in substantially the same width as the protrusion portion18of the unit protection cover16, and bend corner portions between a top wall (reference numeral is omitted) and right and left side walls (reference numeral is omitted) constitute extension ridge lines32B that continue to the right and left extension ridge lines32A of the unit protection cover16.

In the vehicle body rear portion structure of the present embodiment, the protrusion portions18,19at the middle in the vehicle width direction of the unit protection cover16and the rear floor panel11are provided so as to continue to an upper portion of the floor tunnel15. Then, the right and left extension ridge lines32A,32B of the protrusion portions18,19extend so as to continue from the right and left tunnel ridge line31of the floor tunnel15to a vehicle body rearward side. In the present embodiment, the right and left extension ridge lines32A,32B of the unit protection cover16and the rear floor panel11constitute a reinforcement structure portion that extends in a vehicle body rearward direction from the right and left tunnel ridge lines31of the floor tunnel15.

The front floor panel10and the floor tunnel15are constituted by welding a separate terminal panel10e,15eto a rear end portion of a main body panel10a,15a. The front floor panel10is constituted to be separated to right and left sides of the floor tunnel15, and the right and left sides of the front floor panel10are connected to each other via the floor tunnel15. The terminal panel10eof the front floor panel10is also constituted to be separated to right and left sides.

As shown inFIG.2, the terminal panel10eof the front floor panel10includes: a connection flange10efthat is joined to an upper surface of a rear end portion of the main body panel10aof the front floor panel10; a standing wall10erthat stands upward from a rear end portion of the connection flange10ef; and a step wall10esthat extends to be bent rearward from an upper end portion of the standing wall10er. The step wall10esis joined to an upper surface of the step wall16fsof the front wall16fof the unit protection cover16.

The standing wall10erand the step wall10esof the right and left terminal panel10eextend from a connection position with the side sill12on the outer side in the vehicle width direction to a position where at least part of the standing wall10erand the step wall10esoverlap in the vehicle width direction with the floor tunnel15. The right and left terminal panels10emay be constituted as a continuous integral component.

In the terminal panel10eof the front floor panel10, a patch member20having a substantially L shape in a cross-section orthogonal to the vehicle width direction is joined to a rear surface (a surface on the opposite side of a vehicle room side) of the standing wall10erand the step wall10es. The patch member20extends from an outer end portion in the vehicle width direction of the terminal panel10eto the vicinity of the front wall protrusion region18fof the unit protection cover16.

FIG.3is a III arrow view ofFIG.1.

As shown inFIG.1andFIG.3, the terminal panel15eof the floor tunnel15includes: a base portion15ebhaving a substantially U-shape that opens downward; a side flange15es(joint flange) that is bent and extends outward in the vehicle width direction from a rear end portion of the right and left side walls of the base portion15eb; and an upper flange15euthat is bent and extends upward from a rear end portion of the upper wall of the base portion15eb. A bend angle portion between an upper wall of the base portion15eband the upper flange15euconstitutes an intersection ridge line33that extends along the vehicle width direction. The intersection ridge line33extends along the vehicle width direction between the right and left side flange15es(joint flange).

The right and left side flange15esof the terminal panel15eare overlapped with a front surface of the standing wall10erat the rear of the front floor panel10. In this way, the side flange15esthat is overlapped with front surface of the standing wall10eris welded to the standing wall10erand the patch member20on the rear side of the standing wall10erin a triplicated manner.

Reference numeral w in the drawing is given to a weld point of the side flange15es, the standing wall10er, and the patch member20that are overlapped in a triplicated manner.

The upper flange15euof the terminal panel15eis joined to part of the right and left side walls18fsand a front surface of the top wall18ftof the front wall protrusion region18fof the protrusion portion18in the middle of the unit protection cover16.

When the rear portions of the front floor panel10and the floor tunnel15and the front portion of the unit protection cover16are joined together as described above, the step wall10esat the rear of the right and left front floor panel10are arranged adjacent to the outside in the vehicle width direction of the front wall protrusion region18fof the unit protection cover16.

In the vehicle body rear portion of the vehicle1of the present embodiment, the reinforcement structure portion (the extension ridge lines32A,32B) that extends in the vehicle body rearward direction from the tunnel ridge line31at the right and left upper portions of the floor tunnel15is provided on the unit protection cover16and the rear floor panel11. Therefore, the rear portion of the floor tunnel15and the rear floor panel11are connected to each other with high stiffness through the reinforcement structure portion (the extension ridge lines32A,32B). Therefore, in the vehicle body rear portion of the vehicle1of the present embodiment, even when a large torsional load or an impact load in the forward-rearward direction is input to the vehicle1, it is possible prevent deformation or damage of the peripheral portion of the battery unit17(the protection target unit). Accordingly, when the vehicle body rear portion structure of the present embodiment is employed, it is possible to further reliably protect the battery unit17(the protection target unit) arranged at a rearward position of the floor tunnel15.

Further, in the vehicle body rear portion of the vehicle1of the present embodiment, the protrusion portions18,19that rise upward are provided at the middle in the vehicle width direction of the unit protection cover16and the rear floor panel11, and the extension ridge lines32A,32B each extending continuously in the vehicle body rearward direction from each of the right and left tunnel ridge lines31are formed on the protrusion portions18,19. The reinforcement structure portion is constituted of the right and left extension ridge lines32A,32B of the protrusion portions18,19of the unit protection cover16and the rear floor panel11. Therefore, although the vehicle body rear portion structure of the present embodiment has a simple configuration, it is possible to smoothly perform load transmission in the vehicle body forward-rearward direction between the floor tunnel15and the rear floor panel11through the protrusion portions18,19.

Further, in the vehicle body rear portion of the vehicle1of the present embodiment, the unit protection cover16is formed to rise further upward than the upper surface of the floor tunnel15, and the protrusion portion18in the middle in the vehicle width direction of the unit protection cover16includes the front wall protrusion region18fthat is formed on the front wall16fand the upper wall protrusion region18uthat is formed on the upper wall16u. In the present configuration, since the unit protection cover16is formed to rise further upward than the upper surface of the floor tunnel15, it is possible to cover the battery unit17(the protection target unit) from above with a sufficient height by the unit protection cover16. Further, in the present configuration, since the protrusion portion18of the unit protection cover16has the front wall protrusion region18fand the upper wall protrusion region18u, it is possible to perform smooth load transmission between the floor tunnel15and the rear floor panel11through the front wall protrusion region18fand the upper wall protrusion region18u.

Further, in the vehicle body rear portion of the vehicle1of the present embodiment, the protrusion portion18of the unit protection cover16includes the side walls18us,18fsthat extend downward from the extension ridge line32A on the right and left sides, and the side walls18us,18fsare inclined outward in the vehicle width direction and downward from the extension ridge line32A of the protrusion portion18. In the present configuration, the side walls18us,18fson the right and left sides of the protrusion portion18of the unit protection cover16can efficiently perform load transmission in the vehicle body forward-rearward direction in cooperation with the extension ridge line32A of the protrusion portion18. Further, in the present configuration, since the side walls18us,18fson the right and left sides of the protrusion portion18are inclined outward in the vehicle width direction and downward, when an impact load is input to the unit protection cover16from one side of the vehicle, the impact load can be smoothly transmitted to the top walls18ut,18ftof the protrusion portion18through the inclination of the side walls18us,18fslocated at the one side and be smoothly transmitted from the top walls18ut,18ftof the protrusion portion18to the other side of the vehicle through the inclination of the side walls18us,18fslocated at the other side.

Accordingly, when the vehicle body rear portion structure of the present embodiment is employed, at the time of input of an impact load from a sideward direction of the vehicle, it is possible to smoothly transmit the input load to the other side in the vehicle width direction while protecting the battery unit17(the protection target unit).

Further, in the vehicle body rear portion of the vehicle1of the present embodiment, the rear cross member40that extends along the vehicle width direction is provided on the rear floor panel11, and the outer end portion in the vehicle width direction of the rear cross member40is connected to the rear side frame30on the right and left sides which is a skeleton frame. The extension ridge lines32A,32B which are the reinforcement structure portions of the unit protection cover16and the rear floor panel11extend to a position that intersects the rear cross member40. Therefore, in the present configuration, an impact load in the vehicle body forward-rearward direction that is input to the extension ridge lines32A,32B which are the reinforcement structure portions can be received by the rear cross member40that is connected to the rear side frame30on the vehicle body right and left sides.

Accordingly, when the vehicle body rear portion structure of the present embodiment is employed, since the rear portion of the floor tunnel15is connected to the rear side frame30on the vehicle body right and left sides through the extension ridge lines32A,32B and the rear cross member40with high stiffness, it is possible further prevent deformation or damage of the peripheral portion of the battery unit17(the protection target unit).

Further, in the vehicle body rear portion of the vehicle1of the present embodiment, the outer end portion in the vehicle width direction of the terminal panel10eof the front floor panel10is connected to the side sill12which is a skeleton frame on vehicle room right and left sides, and the standing wall10erthat stands upward and the step wall10esthat is bent and extends rearward from the upper end portion of the standing wall10erare formed on the rear edge portion of the terminal panel10e. The rear end portion of the floor tunnel15is joined to the standing wall10erof the terminal panel10e, and the step wall10esof the terminal panel10eis arranged at a position adjacent to the outside in the vehicle width direction of the front wall protrusion region18fof the unit protection cover16. Therefore, when an impact load is input to the unit protection cover16from one side of the vehicle, an input weight can be smoothly transmitted to another side of the vehicle through the step wall10esof the rear portion (the terminal panel10e) of the front floor panel10and the front wall protrusion region18fof the unit protection cover16.

Accordingly, when the present configuration is employed, it is possible to further prevent deformation or damage of the battery unit17(the protection target unit) at the time of input of an impact load from a vehicle sideward direction.

Further, in the vehicle body rear portion of the vehicle1of the present embodiment, the patch member20that extends from the outer end portion (a joint portion with the side sill12) in the vehicle width direction of the terminal panel10eto the vicinity of the front wall protrusion region18fof the unit protection cover16is joined to a rear surface (a surface on the opposite side of the vehicle room side) of the step wall10esand the standing wall10erof the rear portion (the terminal panel10e) of the front floor panel10. Therefore, when an impact load is input to the front region of the unit protection cover16from one side of the vehicle, an input weight can be further efficiently transmitted to another side of the vehicle through the standing wall10erand the step wall10esat the rear portion of the front floor panel10that is reinforced by the patch member20.

Further, in the vehicle body rear portion of the vehicle1of the present embodiment, the pair of side flanges15es(the joint flanges) that are joined to the standing wall10erat the right and left rear portions of the front floor panel10are provided on the rear end portion of the floor tunnel15, and each of the joint flanges15esis welded to the standing wall10erand the patch member20in a triplicated manner. Therefore, an impact load that is input from a vehicle sideward direction through the patch member20and the standing wall10ercan be efficiently transmitted to the rear end portion of the floor tunnel15with high stiffness. Accordingly, when the present configuration is employed, an impact load input to one side of the vehicle can be further efficiently transmitted to another side of the vehicle, and it is possible to further reliably prevent deformation or damage of the battery unit17(the protection target unit).

Further, in the vehicle body rear portion of the vehicle1of the present embodiment, the intersection ridge line33that extends along the vehicle width direction between the right and left side flanges15esare provided on the rear end portion (the terminal panel10e) of the floor tunnel15. Therefore, the stiffness in the vehicle width direction of the rear end portion of the floor tunnel15is enhanced by the intersection ridge line33. As a result, an impact load that is input from one side of the vehicle to the front region of the unit protection cover16is efficiently transmitted from one side flange15esthrough the intersection ridge line33to the other side flange15esat the rear end portion of the floor tunnel15.

Accordingly, when the present configuration is employed, it is possible to further reliably prevent deformation or damage of the battery unit17(the protection target unit) at the time of input of the impact load from a vehicle sideward direction.

The present invention is not limited to the embodiment described above, and various design changes can be made without departing from the scope of the invention.

The above embodiment is described using an example in which the reinforcement structure portion that extends in the vehicle body rearward direction from the tunnel ridge line31at the right and left upper portions of the floor tunnel15is constituted of the pair of extension ridge lines32A,32B formed on the protrusion portions18,19of the unit protection cover16and the rear floor panel11. However, the reinforcement structure portion provided on the unit protection cover16and the rear floor panel11is not limited to the extension ridge lines32A,32B formed on the protrusion portions18,19. For example, a separate batch member may be attached to the unit protection cover16and the rear floor panel11so as to continue the tunnel ridge line31of the floor tunnel15.