Patent Description:
A tunnel portion extending in a vehicle front-rear direction is formed at a vehicle right-left direction central portion of a floor panel of a conventional automobile. The tunnel portion is a part in which an exhaust pipe extending from an engine room on a vehicle front side to a rear portion, a propeller shaft that transfers power of an engine on the vehicle front side to rear wheels, and the like are housed, and thus largely bulges to a position higher than a bottom portion of a seat cushion.

For example, as disclosed in Patent Literature <NUM>, a tunnel frame extending in the vehicle front-rear direction is provided at the upper surface portion of the tunnel portion and a closed cross-section structure extending in the vehicle front-rear direction is constituted by the tunnel portion and the tunnel frame. In the vehicle-body structure of Patent Literature <NUM>, a pair of right and left rear side frames extending in the vehicle front-rear direction are provided on a vehicle rear side of the tunnel portion, and in addition, a pair of right and left central members extending from vehicle rear portions of the tunnel frames to the right and left rear side frames are provided. <CIT> discloses a vehicle body structure consisting of a floor panel and a floor tunnel. A backbone frame is arranged on top of the tunnel. <CIT>discloses a reinforcement arrangement for protecting a vehicle occupant in the event of a front collision. The reinforcement arrangement includes a centrally arranged framework extending from a front wall to a battery frame in a tilted manner. The framework is connected via its end portion to the battery frame. A middle portion of the framework is additionally connected to the battery framework via a single vertical support element.

In an automobile including the tunnel portion as disclosed in Patent Literature <NUM>, the stiffness of a vehicle body can be improved by the tunnel portion, and the stiffness of the vehicle body can be also improved by the closed cross-section structure constituted by the tunnel portion and the tunnel frames and extending in the vehicle front-rear direction and improved by connection of the rear-side frame and the tunnel frames through right and left center members, but it has been a problem how to improve the stiffness of the vehicle body in an automobile including no tunnel portion.

Specifically, a typical tunnel portion largely bulges to a position higher than the bottom portion of the seat cushion as described above, and thus the stiffness of the vehicle body can be improved to some extent only by providing such a tunnel portion, but in an automobile without the tunnel portion, the stiffness of the vehicle body tends to decrease, and furthermore, it is disadvantage in terms of the stiffness that the tunnel frames of Patent Literature <NUM> cannot be provided. Furthermore, right and left side frames of Patent Literature <NUM> cannot be provided since no tunnel frames are provided.

Thus, such a method is thought that reinforces the floor panel itself by joining reinforcement members such as the tunnel frames of Patent Literature <NUM> to upper and lower surface portions of the floor panel to constitute a partial closed cross-section structure at the floor panel. However, since the floor panel is positioned at a lower portion of the vehicle body, it is insufficient to only improve the stiffness of the floor panel, in particular, in order to increase the distortion stiffness of the vehicle body on the whole. If the distortion stiffness of the vehicle body is increased only with a reinforcement structure of the floor panel, a significantly large-scale reinforcement structure needs to be constituted by the reinforcement members, which leads to weight increase and poor efficiency. Thus, when the distortion stiffness of the vehicle body needs to be equivalent to or larger than that in Patent Literature <NUM>, a reinforcement structure as in Patent Literature <NUM> is needed at a part higher than and away from the floor panel, but such a reinforcement structure cannot be employed for the floor panel including no tunnel portion as described above.

Furthermore, when the floor panel is reinforced, simple reinforcement is not enough and it is required to minimize influence of a reinforcement structure on comfort in an occupant space.

The present disclosure has been made in view of the above-described problem and has an objective to sufficiently improve the distortion stiffness of a vehicle body with minimized influence on comfort in an occupant space when no floor tunnel that largely bulges upward from a floor panel is provided.

To achieve the above-described objective, a vehicle-body structure provided in an automobile may be premised in a first aspect of the present disclosure. The vehicle-body structure includes a floor panel constituting a floor of an occupant space suitable for at least one seat on which a passenger is able to sit, and a center frame disposed to be higher than and away from the floor panel at a vehicle-width-direction central portion of the occupant space and extending in a vehicle front-rear direction. The center frame is arranged at a downward tilt toward a vehicle rear side, and a vehicle rear portion of the center frame is connected to the floor panel. In particular, the center frame is disposed to be away from the floor panel at a vehicle-width-direction central portion. Only the rear portion of the center frame may be either directly connected to the floor panel or indirectly connected to the floor panel. In case of an indirect connection between the central frame and the floor panel also the rear portion of the central frame may be spaced apart from the floor panel in an up-down direction of the vehicle.

With this configuration, since the rear portion of the center frame positioned higher than and away from the floor panel is connected to the floor panel, the distortion stiffness of a vehicle body can be sufficiently improved although the floor panel includes no floor tunnel. Moreover, since the height of the center frame decreases at a position farther on the vehicle rear side, the center frame is arranged close to the floor panel. Accordingly, the center frame is not positioned on the upper side in the occupant space and is unlikely to affect comfort in the occupant space.

According to the invention, a traveling motor for driving rear wheels of the automobile is included. The traveling motor is disposed on a vehicle rear side of the rear portion of the center frame. The traveling motor has a barycenter that is set to be lower than an upper end of the rear portion of the center frame and higher than a lower end of the rear portion of the center frame.

With this configuration, when the traveling motor is mounted at a vehicle rear portion, the mount position of the traveling motor can be lowered to provide a larger occupant space or trunk space. Moreover, for example, when an impact load applied from the vehicle rear side is input to the traveling motor and the traveling motor is about to move toward the vehicle front side, a load toward the vehicle front side is applied to the rear portion of the center frame, thereby preventing movement of the traveling motor toward the vehicle front side.

In a preferred aspect of the present invention, the height of an up-down direction central portion of the traveling motor is set to be lower than the height of an up-down direction central portion of the rear portion of the center frame. Specifically, , the height of a rotation center or the rotating axes of the traveling motor extending in the right-left direction of the vehicle is set to be lower than the height of an up-down direction central portion of the rear portion of the center frame.

In a further preferred aspect of the present invention, the structure further comprises a trunk-space-side floor panel constituting a floor of a trunk space. In addition, the structure may comprise a connection panel, which is arranged between the floor panel and the trunk-space-side floor panel. In particular, the connection plate connects a rear portion of the floor panel with a front portion of the trunk-space-side floor panel. Preferably, the floor panel, the trunk-space-side floor panel and the connection panel are integrally formed. Alternatively, the aforementioned components could be formed by separate elements, which are connected together afterwards.

IN a further preferred aspect of the invention, the trunk-space-side floor panel may be positioned higher than the floor panel in an up-down direction of the vehicle. The connection panel may extend in the up-down direction of the vehicle, in particular the connection panel may be arranged vertically or may be tilted extending diagonally from the floor panel at a down-rear position to the trunk-space-side floor panel.

In a further aspect of the present disclosure, a rear portion of the floor panel includes a cross member extending in a vehicle width direction. A connecting member that connects the cross member and the rear portion of the center frame is included.

With this configuration, since the cross member is provided at the rear portion of the floor panel, a vehicle-body reinforcement effect by the cross member is obtained. Moreover, since the rear portion of the center frame is connected to the cross member through the connecting member, the distortion stiffness of the vehicle body can be further improved. Moreover, the lower portion of the rear-portion connecting member may be additionally fixed to the connection panel (<NUM>). Further preferable, the cross member may be fixed to the floor panel and/or to the trunk-space-side floor panel. Also, the cross member may be disposed such that it intersects with the center frame in a plan view in the occupant space.

In a further aspect of the present disclosure, the seat is disposed on each of a vehicle left side and a vehicle right side of the center frame.

With this configuration, since the center frame positioned between the right and left seats has a downward tilt toward the vehicle rear side, a feeling of pressure on passengers sitting on the seats can be reduced.

In a fifth aspect of the present disclosure, a dash panel extending upward from a front portion of the floor panel and partitioning a vehicle front portion of the occupant space is further included. The center frame continuously extends from a part of the dash panel positioned higher than and away from the floor panel to a rear portion of the floor panel.

With this configuration, since the center frame is continuously disposed from the front portion of the occupant space to a rear portion thereof, the distortion stiffness of the vehicle body further increases. The center frame extending to longitudinally traverse the occupant space in the front-rear direction in this manner is advantageous for the vehicle body stiffness but potentially disadvantageous in terms of comfort. However, with the present configuration, since the center frame has a downward tilt toward the vehicle rear side, influence on comfort is minimized.

According to a preferred aspect of the invention, the floor panel has a tunnel less structure. It is also preferable when the distance between a lower surface of the center frame and the upper surface of the floor panel is equal to or larger than <NUM> at a part separated most. Moreover, it is further advantageous when the distance between a lower surface of the center frame and the upper surface of the floor panel equal to or larger than <NUM> at a part separated most.

A further aspect of the invention is directed to a vehicle comprising the vehicle body structure according to the invention. The technical advantages of the vehicle obviously correspond to the advantages discussed above with respect to the inventive structure. The vehicle may be passenger automobile.

As described above, since a center frame disposed to be higher than and away from a floor of an occupant space has a downward tilt toward a vehicle rear side, the distortion stiffness of a vehicle body can be sufficiently improved with minimized influence on comfort in the occupant space.

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. The following description of the preferable embodiment is merely exemplary in essence and not intended to limit the present invention, its application, nor its usage.

<FIG> is a side view of an automobile <NUM> including a vehicle-body structure A according to the embodiment of the present invention when viewed from left. In description of the embodiment, a vehicle front-rear direction is simply referred to as a "front-rear direction", a vehicle front side is simply referred to as a "front side", and a vehicle "rear side" is simply referred to as a "rear side". In addition, a vehicle width direction is the right-left direction of the vehicle, a vehicle left side is simply referred to as a "left side", and a vehicle right side is simply referred to as a "right side".

The automobile <NUM> is a passenger automobile, and an occupant space R1 in which a passenger boards is provided at a front-rear direction intermediate portion of the automobile <NUM>. The occupant space R1 includes front seats (front-row seats) FS included in a front row, and rear seats (rear-row seats) RS included in a rear row. The front seats FS include a driver seat arranged on the right side (or the left side) in the occupant space R1, and a front passenger seat arranged on the left side (or the right side) in the occupant space R1. The rear seats RS are arranged on the right and left sides, respectively, in the occupant space R1. Although not illustrated, third-row seats may be arranged on the rear side of the rear seats RS. The rear seats RS are not essential and may be omitted.

A front door FD and a rear door RD are disposed on each of the left and right sides of the occupant space R1. The rear door RD may be omitted in a case of the automobile <NUM> including no rear seats RS.

A front-side space R2 is provided on the front side of the occupant space R1 in the automobile <NUM>. A powertrain PT can be mounted in the front-side space R2 as necessary. When the powertrain PT is mounted in the front-side space R2, the front-side space R2 may be called, for example, a powertrain storage room, a motor room, or an engine room. A bonnet hood BF is provided at an upper portion of the front-side space R2.

A trunk space R3 in which a package or the like can be housed is provided on the rear side of the occupant space R1 in the automobile <NUM>. The trunk space R3 can be opened and closed by a trunk lid TR. A rear-side space R4 is provided on the rear side of the occupant space R1 and at a position lower than the trunk space R3 in the automobile <NUM>. The powertrain PT that generates power for the automobile <NUM> can be mounted in the rear-side space R4 as necessary. When the powertrain PT is mounted in the rear-side space R4, the rear-side space R4 may be called, for example, a powertrain storage room, a motor room, or an engine room.

The powertrain PT may be mounted in each of the front-side space R2 and the rear-side space R4 or the powertrain PT may be mounted in one of them. A front-wheel-drive vehicle in which only front wheels FT are driven by the powertrain PT is achieved when the powertrain PT is mounted only in the front-side space R2, or a rear-wheel-drive vehicle in which only rear wheels RT are driven by the powertrain PT is achieved when the powertrain PT is mounted only in the rear-side space R4. Alternatively, a four-wheel-drive vehicle is achieved when the front wheels FT and the rear wheels RT are driven by the powertrains PT mounted in both the front-side space R2 and the rear-side space R4.

Each powertrain PT includes at least a traveling motor M (illustrated in <FIG>) for driving a drive wheel and also includes a speed reducer, a transmission, or the like as necessary. Thus, the automobile <NUM> is an electric vehicle. The traveling motor M is disposed such that the rotation center thereof extends in the right-left direction. The powertrain PT may include, for example, a controller in addition to the traveling motor M. The powertrain PT may include an internal combustion engine. A battery unit Y (also illustrated in <FIG>) for supplying electric power to the traveling motor M is mounted at a lower portion of the automobile <NUM>. For example, the battery unit Y may be charged by using power generated by the internal combustion engine, and either the front wheels FT or the rear wheels RT or both may be driven by power generated by the internal combustion engine.

The type of the automobile <NUM> does not necessarily need to be a four-door vehicle as exemplarily illustrated in <FIG> and may be, for example, an automobile including no rear doors RD. Although not illustrated, the present invention is also applicable to an automobile, such as a hatchback vehicle, in which the rear-side space R4 can be opened and closed by a tail gate.

As illustrated in <FIG>, the automobile <NUM> includes a lower-portion structural body <NUM> and an upper-portion structural body <NUM>, and the vehicle-body structure A is constituted by the lower-portion structural body <NUM> and the upper-portion structural body <NUM>. <FIG> illustrates a state in which the doors FD and RD, the bonnet hood BF, a fender, window glasses, a roof, a center pillar, a rear pillar, a bumper, front and rear lighting devices, an instrument panel, the front and rear seats, and the like, which are included in the upper-portion structural body <NUM> in reality, are removed. <FIG> also illustrates a state in which the front wheels FT, the rear wheels RT, a suspension device, and the like, which are included in the lower-portion structural body <NUM> in reality, are removed.

The lower-portion structural body <NUM> includes the battery unit Y. The battery unit Y includes a front-side battery FB, a rear-side battery RB, and a rack frame <NUM> surrounding the front-side battery FB and the rear-side battery RB. The lower-portion structural body <NUM> also includes a front support frame <NUM> extending from a front portion of the rack frame <NUM> toward the front side, and a rear support frame <NUM> extending from a rear portion of the rack frame <NUM> toward the rear side.

Although not illustrated, in a typical electric automobile, a battery unit is often detachably attached as a separated body from a vehicle body under a floor, but in the present embodiment, not only the batteries FB and RB but also the front support frame <NUM> and the rear support frame <NUM> are integrated with the rack frame <NUM> surrounding the batteries FB and RB, and the front support frame <NUM> and the rear support frame <NUM> are detachably attached to the upper-portion structural body <NUM> together with the batteries FB and RB.

Specifically, the automobile <NUM> of the present embodiment is configured to be able to be divided in the up-down direction into the lower-portion structural body <NUM> including the batteries FB and RB, and the upper-portion structural body <NUM> in which the occupant space R1 and the trunk space R3 are formed. Being able to be divided in the up-down direction means integration of the lower-portion structural body <NUM> with the upper-portion structural body <NUM> by using fastening members such as bolts and nuts, screws, and the like without using welding, bonding, and the like. Accordingly, the lower-portion structural body <NUM> can be separated from the upper-portion structural body <NUM> as necessary when maintenance and repair are performed after the automobile <NUM> is handed over to a user, and thus maintainability is excellent.

A vehicle-body structure of a ladder frame type is known as the vehicle-body structure of an automobile. In a case of the vehicle-body structure of the ladder frame type, division into a ladder frame and a cabin in the up-down direction is possible, but the ladder frame continuously extends in the front-rear direction and thus mainly receives a collision load at front collision and rear collision. At side collision, the ladder frame only supplementarily receives a collision load, and the collision load is mainly received by the cabin. In this manner, in the vehicle-body structure of the ladder frame type, it is normal that a member that receives a collision load is different between front or rear collision and side collision.

However, in a case of the automobile <NUM> of the present embodiment, the lower-portion structural body <NUM>, which includes the front support frame <NUM> and the rear support frame <NUM>, and the upper-portion structural body <NUM> can be divided from each other, but its technical idea is largely different from that of the conventional vehicle-body structure of the ladder frame type in that a collision load is received by the lower-portion structural body <NUM> and the upper-portion structural body <NUM> in both cases of front or rear collision and side collision and thus the collision load can be dispersed to and absorbed by the structural bodies <NUM> and <NUM>. Hereinafter, the structures of the lower-portion structural body <NUM> and the upper-portion structural body <NUM> will be sequentially described.

First, the lower-portion structural body <NUM> will be described below. The lower-portion structural body <NUM> includes the powertrain PT, the front wheels FT, the rear wheels RT, and front-side suspension devices SP1 and SP2 and rear-side suspension devices SP3 and SP4, which are illustrated with virtual lines in <FIG>, in addition to the batteries FB and RB, the rack frame <NUM>, the front support frame <NUM>, and the rear support frame <NUM>. The formats of the front-side suspension devices SP1 and SP2 and the rear-side suspension devices SP3 and SP4 are not particularly limited, and the vehicle-body structure may be changed in accordance with the formats of the front-side suspension devices SP1 and SP2 and the rear-side suspension devices SP3 and SP4.

As illustrated in <FIG>, the rack frame <NUM> as a framework of the battery unit Y is a member for surrounding and protecting the front-side battery FB, the rear-side battery RB, harnesses, and the like. The rack frame <NUM> is formed in such a large size that, on the lower side of an occupant-space-side floor panel <NUM> to be described later, the rack frame <NUM> extends from the vicinity of a left end portion of the occupant-space-side floor panel <NUM> to the vicinity of a right end portion thereof and extends from the vicinity of a front end portion of the occupant-space-side floor panel <NUM> to the vicinity of a rear end portion thereof. In this manner, since the rack frame <NUM> is provided in a large part of a region on the lower side of the occupant-space-side floor panel <NUM>, the batteries FB and RB having large capacities can be mounted on the automobile <NUM>. The batteries FB and RB may be, for example, lithium-ion batteries or all-solid-state batteries or may be any other secondary batteries. Alternatively, the batteries FB and RB may be what is called battery cells or may be battery packs in which a plurality of battery cells are housed.

The rack frame <NUM> includes a left side member <NUM>, a right side member <NUM>, a front-side member <NUM>, and a rear-side member <NUM>. The left side member <NUM>, the right side member <NUM>, the front-side member <NUM>, and the rear-side member <NUM> are formed of, for example, an extruded material made of an aluminum alloy, but may be formed of a press-formed material such as an aluminum alloy plate material or a steel plate. In description below, an "extruded material" is an extruded material made of an aluminum alloy, and a "press-formed material" is a press-formed material such as an aluminum alloy plate material or a steel plate. Alternatively, each member may be formed of, for example, cast metal or die cast.

A cross-sectional shape of each of the left side member <NUM>, the right side member <NUM>, the front-side member <NUM>, and the rear-side member <NUM> in a direction orthogonal to its longitudinal direction is a rectangular shape. The left side member <NUM>, the right side member <NUM>, the front-side member <NUM>, and the rear-side member <NUM> are all arranged at the same height and substantially horizontally extend. When the lower-portion structural body <NUM> is to be connected to the upper-portion structural body <NUM>, the front-side member <NUM> is fastened and fixed to a lower portion of a dash panel <NUM> by a fastening member, and the left side member <NUM> and the right side member <NUM> are fastened and fixed to right and left side sills <NUM>, respectively, by fastening members. The rear-side member <NUM> is fastened and fixed to a connection panel <NUM>, which will be described later, by a fastening member.

The left side member <NUM> is provided at a left end portion of the lower-portion structural body <NUM> and extends in the front-rear direction. The right side member <NUM> is provided at a right end portion of the lower-portion structural body <NUM> and extends in the front-rear direction. The left side member <NUM> and the right side member <NUM> are arranged on a vehicle-width-direction inner side of the right and left side sills <NUM>, respectively, to be described later. The front-side member <NUM> is provided at a front portion of the battery unit Y and extends in the right-left direction from a front end portion of the left side member <NUM> to a front end portion of the right side member <NUM>. A left end portion of the front-side member <NUM> and the front end portion of the left side member <NUM> are connected to each other, and a right end portion of the front-side member <NUM> and the front end portion of the right side member <NUM> are connected to each other. The rear-side member <NUM> is provided at a rear portion of the battery unit Y and extends in the right-left direction from a rear end portion of the left side member <NUM> to a rear end portion of the right side member <NUM>. A left end portion of the rear-side member <NUM> and the rear end portion of the left side member <NUM> are connected to each other, and a right end portion of the rear-side member <NUM> and the rear end portion of the right side member <NUM> are connected to each other.

A cover member <NUM> as a bottom plate is attached to a lower portion of the rack frame <NUM>. The rack frame <NUM> is blocked from the lower side by the cover member <NUM>. The cover member <NUM> substantially horizontally extends and is fixed to lower surfaces of the left side member <NUM>, the right side member <NUM>, the front-side member <NUM>, and the rear-side member <NUM> and also fixed to the side sills <NUM> as described later. Note that an upper portion of the rack frame <NUM> may be blocked by a non-illustrated lid or may be blocked by the occupant-space-side floor panel <NUM> to be described later. Note that electric power of the batteries FB and RB housed in the rack frame <NUM> is supplied to the traveling motor M through a non-illustrated traveling control circuit. The batteries FB and RB can be charged through a non-illustrated charging socket.

<FIG> illustrates a cross-section of a right-left direction central portion of the vehicle-body structure A. As illustrated in <FIG>, first to third battery-side cross members 10A, 10B, and 10C as reinforcement members extending in the right-left direction are provided inside the rack frame <NUM>. The heights of the first to third battery-side cross members 10A, 10B, and 10C are all the same and are the same as the heights of the front-side member <NUM> and the rear-side member <NUM>. The first to third battery-side cross members 10A, 10B, and 10C may be formed of extruded materials or may be formed of press-formed materials. In the present embodiment, the three battery-side cross members 10A, 10B, and 10C are provided, but the number of the battery-side cross members 10A, 10B, and 10C may be increased or decreased in accordance with dimensions of the rack frame <NUM> in the front-rear direction.

The first to third battery-side cross members battery-side cross members 10A, 10B, and 10C are arranged at an interval from each other in the front-rear direction, the first battery-side cross member 10A is positioned farthest on the front side, and the third battery-side cross member 10C is positioned farthest on the rear side. Lower portions of the battery-side cross members 10A, 10B, and 10C are fixed to an upper surface of the cover member <NUM>. Left end portions of the battery-side cross members 10A, 10B, and 10C are fixed to an inner surface (right-side surface) of the left side member <NUM>, and right end portions of the battery-side cross members 10A, 10B, and 10C are fixed to an inner surface (left-side surface) of the right side member <NUM>. In other words, the battery-side cross members 10A, 10B, and 10C are members connecting the left side member <NUM> and the right side member <NUM>.

A front-portion central member <NUM> and first to third rear-portion central members <NUM> to <NUM> as reinforcement members extending in the front-rear direction are provided inside the rack frame <NUM>. The front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> may be referred to as a battery frame extending in the front-rear direction, and the battery unit Y has a structure including the battery frame constituted by the front-portion central member <NUM>, the first to third rear-portion central members <NUM> to <NUM>, and the like. The left side member <NUM>, the right side member <NUM>, the front-side member <NUM>, and the rear-side member <NUM> may be included in the battery frame.

The front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> are arranged at substantially same heights and provided at a right-left direction center of the rack frame <NUM>. Lower end portions of the front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> are attached to the upper surface of the cover member <NUM>. The front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> extend from the front-side member <NUM> to the rear-side member <NUM>.

The front-portion central member <NUM> is arranged between the front-side member <NUM> and the first battery-side cross member 10A, a front end portion of the front-portion central member <NUM> is fixed to a right-left direction central portion of the front-side member <NUM>, and a rear end portion of the front-portion central member <NUM> is fixed to a right-left direction central portion of the first battery-side cross member 10A. Accordingly, the front-side member <NUM> is a member extending to connect the front end portions of the left side member <NUM> and the right side member <NUM> to the front end portion of the front-portion central member <NUM>.

The first rear-portion central member <NUM> is arranged between the first battery-side cross member 10A and the second battery-side cross member 10B, a front end portion of the first rear-portion central member <NUM> is fixed to the right-left direction central portion of the first battery-side cross member 10A, and a rear end portion of the first rear-portion central member <NUM> is fixed to a right-left direction central portion of the second battery-side cross member 10B. The second rear-portion central member <NUM> is arranged between the second battery-side cross member 10B and the third battery-side cross member 10C, a front end portion of the second rear-portion central member <NUM> is fixed to the right-left direction central portion of the second battery-side cross member 10B, and a rear end portion of the second rear-portion central member <NUM> is fixed to a right-left direction central portion of the third battery-side cross member 10C. The third rear-portion central member <NUM> is arranged between the third battery-side cross member 10C and the rear-side member <NUM>, a front end portion of the third rear-portion central member <NUM> is fixed to the right-left direction central portion of the third battery-side cross member 10C, and a rear end portion of the third rear-portion central member <NUM> is fixed to a right-left direction central portion of the rear-side member <NUM>. Accordingly, the first to third battery-side cross members 10A, 10B, and 10C and the front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> are disposed in a lattice shape and connected to each other inside the rack frame <NUM>, which further increases the effect of reinforcing the rack frame <NUM> and thus the effect of reinforcing the lower-portion structural body <NUM>.

When a virtual straight line extending in the front-rear direction in a plan view is assumed, the positions of the front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> in the right-left direction are set such that the members are arranged on the virtual line. In other words, the members are provided such that the first to third rear-portion central members <NUM> to <NUM> are positioned on a virtual extended line from the front-portion central member <NUM> on the rear side. Note that the front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> may be formed as one member that is continuous in the front-rear direction. In this case, the one member extends from the front-side member <NUM> to the rear-side member <NUM>.

As illustrated in <FIG>, a pair of right and left front support frames <NUM> are provided and substantially horizontally extend in straight lines on the lower side of the upper-portion structural body <NUM>. Each front support frame <NUM> may be formed of, for example, an extruded material or a press-formed material. In the present embodiment, each front support frame <NUM> is formed of an extruded material, and thus a cross-sectional shape thereof in a direction orthogonal to the front-rear direction is substantially constant from a front end portion to a rear end portion.

The left-side front support frame <NUM> is connected to a site on the left side of a right-left direction center of the front-side member <NUM> constituting the front portion of the rack frame <NUM>, and this connection site is positioned on the right side of the left side member <NUM> of the rack frame <NUM>. The right-side front support frame <NUM> is connected to a site on the right side of the right-left direction center of the front-side member <NUM>, and this connection site is positioned on the left side of the right side member <NUM> of the rack frame <NUM>. The heights of the right and left front support frames <NUM> are substantially same.

The front-side powertrain PT is attached to each front support frame <NUM> through a non-illustrated mounting member. In this case, the front support frame <NUM> serves as a front-side motor support frame that supports the traveling motor M on the front side of the battery unit Y. In the lower-portion structural body <NUM>, drive shafts S1 through which output from the powertrain PT (rotational force of the traveling motor M) is transferred to the right and left front wheels FT, respectively, are provided on the right and left sides.

Right and left suspension arms constituting parts of the front-side suspension devices SP1 and SP2 illustrated with virtual lines in <FIG> are freely swingably supported to the right and left front support frames <NUM>, respectively, in the up-down direction. The front support frames <NUM> may be members for supporting the suspension arms without supporting the powertrain PT.

As illustrated in <FIG>, similarly to the front support frames <NUM>, a pair of right and left rear support frames <NUM> are provided and substantially horizontally extend in straight lines toward the rear side. Each rear support frame <NUM> may be formed of, for example, an extruded material or a press-formed material. In the present embodiment each rear support frame <NUM> is formed of an extruded material.

The left-side rear support frame <NUM> is connected to a site on the left side of a right-left direction center of the rear-side member <NUM> constituting the rear portion of the rack frame <NUM>, and this connection site is positioned on the right side of the left side member <NUM> of the rack frame <NUM>. The right-side rear support frame <NUM> is connected to a site on the right side of the right-left direction center of the rear-side member <NUM>, and this connection site is positioned on the left side of the right side member <NUM> of the rack frame <NUM>.

The rear-side powertrain PT is attached to each rear support frame <NUM> through a non-illustrated mounting member. In this case, the rear support frame <NUM> serves as a rear-side motor support frame that supports the rear-side traveling motor M of the battery unit Y. In the lower-portion structural body <NUM>, drive shafts S2 through which output from the powertrain PT (rotational force of the traveling motor M) is transferred to the right and left rear wheels, respectively, are provided on the right and left sides.

Right and left suspension arms constituting parts of the rear-side suspension devices SP3 and SP4 illustrated with virtual lines in <FIG> are freely swingably supported to the right and left rear support frames <NUM>, respectively, in the up-down direction. The rear support frames <NUM> may be members for supporting the suspension arms without supporting the powertrain PT.

Subsequently, the upper-portion structural body <NUM> will be described below. The upper-portion structural body <NUM> includes a floor member <NUM>, the dash panel <NUM>, and the pair of right and left side sills <NUM>. The floor member <NUM> is a member arranged at a higher position than the rack frame <NUM> and the rear support frames <NUM> of the lower-portion structural body <NUM>. The floor member <NUM> includes the occupant-space-side floor panel (first floor panel) <NUM> constituting a floor of the occupant space R1 including the front seats FS and the rear seats RS (illustrated in <FIG>) on which passengers sits, a trunk-space-side floor panel (second floor panel) <NUM> constituting a floor of the trunk space R3, and the connection panel <NUM> connecting a rear portion of the occupant-space-side floor panel <NUM> and a front portion of the trunk-space-side floor panel <NUM>. A kick-up portion is constituted by the connection panel <NUM>.

The floor member <NUM> may be formed of, for example, a member shaped by pressing a steel plate or the like. The occupant-space-side floor panel <NUM>, the trunk-space-side floor panel <NUM>, and the connection panel <NUM> may be integrally formed or may be formed by separately forming components and then connecting them. In the present embodiment, description is made with the three divided portions of the occupant-space-side floor panel <NUM>, the trunk-space-side floor panel <NUM>, and the connection panel <NUM>, but the floor member <NUM> including the panels <NUM> to <NUM> may be referred to as a floor panel. Alternatively, only the occupant-space-side floor panel <NUM> may be referred to as a floor panel.

The occupant-space-side floor panel <NUM> extends from a front portion of the occupant space R1 to a rear portion thereof and from a left-side portion of the occupant space R1 to a right-side portion thereof. The occupant-space-side floor panel <NUM> according to the present embodiment has a floor tunnel-less structure including no tunnel portion. Specifically, a vehicle-width-direction central portion of a floor panel of a conventional automobile is typically provided with a tunnel portion largely bulging upward and extending in the front-rear direction. The tunnel portion is a part for allowing, for example, insertion of an exhaust pipe extending toward the rear side from an engine mounted in an engine room at a vehicle front portion and insertion of a propeller shaft through which output from the engine mounted in the engine room at the vehicle front portion is transferred to rear wheels. The diameters of the exhaust pipe and the propeller shaft are often, for example, equal to or larger than <NUM>, and furthermore, a gap of at least several centimeters or larger needs to be provided between each of the exhaust pipe and the propeller shaft and the floor panel to prevent interference of the exhaust pipe or the propeller shaft with the floor panel. In addition, for example, an insulator is disposed on an inner surface of the tunnel portion in some cases. With these factors, the height of bulging of the tunnel portion from the floor panel is, for example, equal to or larger than <NUM> or equal to or larger than <NUM> in some cases, and as for a positional relation with a seat, an upper end of the tunnel portion is higher than a lower end of a seat cushion on a seat rail or an up-down direction central portion of the seat cushion. A structure without such a tunnel portion largely bulging upward is a tunnel-less structure.

The occupant-space-side floor panel <NUM> includes no tunnel portion having a height equal to or larger than <NUM> or equal to or larger than <NUM> from an upper surface of the occupant-space-side floor panel <NUM> as described above, but may include, for example, a bulging portion having a low height equal to or smaller than <NUM> or equal to or smaller than <NUM> from the upper surface of the occupant-space-side floor panel <NUM>. In a case of such a bulging portion having a low height, neither exhaust pipe nor a propeller shaft can be inserted inside the bulging portion, and thus the bulging portion does not function as a tunnel portion. Thus, the occupant-space-side floor panel <NUM>, which includes a bulging portion having a low height equal to or smaller than <NUM> or equal to or smaller than <NUM> from the upper surface of the occupant-space-side floor panel <NUM>, is a floor panel of a tunnel-less structure. In addition, the occupant-space-side floor panel <NUM> may be provided with, for example, a rib protruding upward and extending in the front-rear direction. The height of such a rib is several centimeters approximately, and thus the floor panel is of a tunnel-less structure even when provided with the rib.

In the present embodiment, since each powertrain PT includes the traveling motor M, no internal combustion engine needs to be mounted in the front-side space R2 and thus no exhaust pipe needs to be guided to the vehicle rear side. When a powertrain PT is mounted in the rear-side space R4, the rear wheels RT can be driven by the powertrain PT and a propeller shaft can be omitted. Accordingly, the occupant-space-side floor panel <NUM> can have a tunnel-less structure.

As illustrated in <FIG> as well, a recessed portion 41a formed bulging downward is formed at a front-rear direction intermediate portion of the occupant-space-side floor panel <NUM>. The recessed portion 41a has a bottom surface 41b on which the feet of a rear-seat passenger sitting on a rear seat RS can be placed. The bottom surface 41b is substantially horizontally formed. A front-side part of the recessed portion 41a is formed to be gradually deeper toward the rear side. The recessed portion 41a may be continuously formed from a left side portion of the occupant-space-side floor panel <NUM> to a right side portion thereof.

The bottom surface 41b of the recessed portion 41a has a height substantially same as that of a lower portion of the corresponding side sill <NUM> to be described later, and accordingly, the height of the bottom surface 41b is sufficiently low. The positional relation between the recessed portion 41a and a seat cushion of each rear seat RS in the front-rear direction is set such that the feet of a rear-seat passenger sitting on the rear seat RS are naturally placed on the bottom surface 41b when the feet are held directly downward. The position of a front portion of the recessed portion 41a is set such that the feet of a rear-seat passenger sitting on the rear seat RS are placed on the bottom surface 41b even when the feet are moved obliquely forward. In other words, the position of the recessed portion 41a and the dimension thereof in the front-rear direction are set such that the feet of a rear-seat passenger can be placed on the bottom surface 41b when the feet are moved somehow in the front-rear direction. Accordingly, a foot space for a rear-seat passenger can be expanded, which improves comfortability. The depth of the recessed portion 41a may be, for example, <NUM> or larger, or <NUM> or larger.

A floor frame 41c extending in the front-rear direction is provided at a right-left direction central portion of the recessed portion 41a. A lower portion of the floor frame 41c is fixed to the bottom surface 41b of the recessed portion 41a. A part at which the recessed portion 41a is formed at the occupant-space-side floor panel <NUM> can be reinforced since the floor frame 41c is provided.

The trunk-space-side floor panel <NUM> is positioned higher than the occupant-space-side floor panel <NUM>. The rear-side space R4 is positioned lower than the trunk-space-side floor panel <NUM>. In other words, the trunk-space-side floor panel <NUM> is arranged to separate the trunk space R3 from the rear-side space R4. The dimension of the trunk-space-side floor panel <NUM> in the front-rear direction is set to be shorter than the dimension of the occupant-space-side floor panel <NUM> in the front-rear direction.

Since the trunk-space-side floor panel <NUM> is arranged at a higher position than the occupant-space-side floor panel <NUM>, the connection panel <NUM> extends in the up-down direction. The connection panel <NUM> may be vertical or may be tilted such that the connection panel <NUM> is positioned farther on the rear side at a position farther on the upper side.

As illustrated in <FIG> as well, the dash panel <NUM> is a member as a partition wall between the front-side space R2 and the occupant space R1 and extends upward from a front portion of the occupant-space-side floor panel <NUM> and in the right-left direction as well, thereby partitioning the front portion of the occupant space R1.

As illustrated in <FIG>, the right and left side sills <NUM> are disposed extending in the front-rear direction at right and left end portions, respectively, of the occupant-space-side floor panel <NUM>. The left end portion of the occupant-space-side floor panel <NUM> is connected to an up-down direction intermediate portion of the left side sill <NUM>, an upper part of the side sill <NUM> protrudes upward from a connection site of the occupant-space-side floor panel <NUM>, and a lower part of the side sill <NUM> protrudes downward from the connection site of the occupant-space-side floor panel <NUM>. Since the battery unit Y including the batteries FB and RB is disposed at a lower position than the occupant-space-side floor panel <NUM>, such arrangement is made that the lower part of the side sill <NUM> overlaps with the batteries FB and RB in a vehicle side view. Similarly, the right side sill <NUM> is connected to the right end portion of the occupant-space-side floor panel <NUM>.

As illustrated in <FIG>, the upper-portion structural body <NUM> includes a pair of right and left hinge pillars <NUM>. The right hinge pillar <NUM> extends upward from a front end portion of the right side sill <NUM>. The left hinge pillar <NUM> extends upward from a front end portion of the left side sill <NUM>. The right and left front doors FD (illustrated in <FIG>) are rotatably attached to the right and left hinge pillars <NUM>, respectively. A left edge portion of the dash panel <NUM> is connected to a right-side surface of the left hinge pillar <NUM>. A right edge portion of the dash panel <NUM> is connected to a left-side surface of the right hinge pillar <NUM>. Note that, although not illustrated, the upper-portion structural body <NUM> is also provided with a center pillar, a rear pillar, and the like.

A left-side front-wheel suspension support member 51A that supports the suspension device (front suspension device) SP1 (illustrated with virtual lines in <FIG>) for the left front wheel FT is provided on the left side on the front side of the dash panel <NUM> in the upper-portion structural body <NUM>. A right-side front-wheel suspension support member 51B that supports the suspension device (front suspension device) SP2 (illustrated with virtual lines in <FIG>) for the right front wheel FT is provided on the right side on the front side of the dash panel <NUM> in the upper-portion structural body <NUM>. The suspension devices SP1 and SP2 are not limited to a particular format but include suspension arms that freely swingably support the front wheels FT in the up-down direction, shock absorbers, springs, or the like. End portions of the suspension arms on the vehicle body side, upper end portions of the shock absorbers, or the like are attached to the front-wheel suspension support members 51A and 51B. The front-wheel suspension support members 51A and 51B can be made of, for example, aluminum die cast, but are not limited thereto and may be made of a combination of steel plates or the like.

As illustrated in, for example, <FIG>, three left-side fixation frames 52A for fixing the left-side front-wheel suspension support member 51A are provided on the left side on the front side of the dash panel <NUM>. The three left-side fixation frames 52A are arranged at an interval from each other in the up-down direction, and front portions of the three left-side fixation frames 52A are fixed to the front-wheel suspension support member 51A. Rear portions of the left-side fixation frames 52A arranged uppermost and at an up-down direction intermediate position are fixed to the left-side hinge pillar <NUM> and the left side of the dash panel <NUM>. A rear portion of the left-side fixation frame 52A arranged lowermost is fixed to the left side sill <NUM>.

As partially illustrated in <FIG>, three right-side fixation frames 52B for fixing the right-side front-wheel suspension support member 51B are provided on the right side on the front side of the dash panel <NUM>. The three right-side fixation frames 52B are arranged at an interval from each other in the up-down direction, and front portions of the three right-side fixation frames 52B are fixed to the front-wheel suspension support member 51B. Rear portions of the right-side fixation frames 52B arranged uppermost and at an up-down direction intermediate position are fixed to the right-side hinge pillar <NUM> and the right side of the dash panel <NUM>. A rear portion of the right-side fixation frame 52B arranged lowermost is fixed to the right side sill <NUM>.

As illustrated in <FIG>, a left-side crush can 53A is fixed to a front portion of the left-side front-wheel suspension support member 51A. A right-side crush can 53B is fixed to a front portion of the right-side front-wheel suspension support member 51B. A bumper reinforcement <NUM> is attached to a front portion of the left-side crush can 53A and a front portion of the right-side crush can 53B.

As illustrated in <FIG>, the upper-portion structural body <NUM> includes a left-side front frame 54A and a right-side front frame 54B. Specifically, the left-side front frame 54A connecting a front portion of a center frame <NUM> to be described later and the left-side front-wheel suspension support member 51A, and the right-side front frame 54B connecting the front portion of the center frame <NUM> and the right-side front-wheel suspension support member 51B are provided on the front side of the dash panel <NUM>. The left-side front frame 54A is tilted such that the left-side front frame 54A is positioned farther on the left side at a position farther on the front side. The right-side front frame 54B is tilted such that the right-side front frame 54B is positioned farther on the right side at a position farther on the front side.

The upper-portion structural body <NUM> includes a left-side rear-side frame 112A extending in the front-rear direction on the left side on the rear side of the rear portion of the occupant-space-side floor panel <NUM>, and a right-side rear-side frame 112B extending in the front-rear direction on the right side on the rear side of the rear portion of the occupant-space-side floor panel <NUM>. A front portion of the left-side rear-side frame 112A is connected to a rear portion of the left-side side sill <NUM>. A front portion of the right-side rear-side frame 112B is connected to a rear portion of the right-side side sill <NUM>. A front-rear direction intermediate portion of the left-side rear-side frame 112A and a front-rear direction intermediate portion of the right-side rear-side frame 112B are connected to each other through a trunk-side cross member (connecting member) <NUM> extending in the right-left direction.

A left-side rear-wheel suspension support member 110A that supports the suspension device (rear suspension device) SP3 (illustrated with virtual lines in <FIG>) for the left rear wheel RT is provided on the left side on the rear side of the connection panel <NUM> in the upper-portion structural body <NUM>. The rear-wheel suspension support member 110A is fixed to the left-side rear-side frame 112A. A right-side rear-wheel suspension support member 110B that supports the suspension device (rear suspension device) SP4 (illustrated with virtual lines in <FIG>) for the right rear wheel RT is provided on the right side on the rear side of the connection panel <NUM> in the upper-portion structural body <NUM>. The rear-wheel suspension support member 110B is fixed to the right-side rear-side frame 112B. The suspension devices SP3 and SP4 are not limited to a particular format but include suspension arms that freely swingably support the rear wheels RT in the up-down direction, shock absorbers, springs, or the like.

An upper portion of the spring or shock absorber included in the left-side suspension device SP3 is connected to an upper portion of the rear-wheel suspension support member 110A. As illustrated in <FIG>, the upper portion of the rear-wheel suspension support member 110A is a left-side load input portion 110a to which loads from the springs or the shock absorbers are input. An upper portion of the spring or shock absorber included in the right-side suspension device SP4 is connected to an upper portion of the rear-wheel suspension support member 110B. The upper portion of the rear-wheel suspension support member 110B is a right-side load input portion 110b to which a load from the spring or the shock absorber is input. The left-side load input portion 110a and the right-side load input portion 110b are also fixed to the right and left sides of the trunk-space-side floor panel <NUM>. In addition, the left-side load input portion 110a and the right-side load input portion 110b are connected to each other through the trunk-side cross member <NUM>. The trunk-side cross member <NUM> is joined to an upper surface of the trunk-space-side floor panel <NUM>, and a closed cross-section structure extending in the vehicle width direction is constituted by the trunk-space-side floor panel <NUM> and the trunk-side cross member <NUM>.

As illustrated in <FIG>, a rear-portion cross member 44E is provided at a lower position than the left-side load input portion 110a and the right-side load input portion 110b, and the rear-portion cross member 44E is positioned at a place lower than the left-side load input portion 110a and the right-side load input portion 110b. The rear-portion cross member 44E is joined to the rear portion of the occupant-space-side floor panel <NUM>.

The upper-portion structural body <NUM> can be partitioned into, for example, a front-portion vehicle-body structure and a rear-portion vehicle-body structure. As illustrated in <FIG>, the rear-portion vehicle-body structure may be the rear side of the occupant-space-side floor panel <NUM> in the upper-portion structural body <NUM>. A left-side rear frame 111A connecting a rear portion of the center frame <NUM> and the left-side rear-wheel suspension support member 110A, and a right-side rear frame 111B connecting the rear portion of the center frame <NUM> and the right-side rear-wheel suspension support member 110B are provided on the rear side of the connection panel <NUM> of the upper-portion structural body <NUM>. Since the right and left rear-wheel suspension support members 110A and 110B are each connected to the rear portion of the center frame <NUM>, the stiffness of the rear-wheel suspension support members 110A and 110B is increased, which improves maneuvering stability of the vehicle. In addition, the stiffness of the vehicle rear side including the vicinity of the connection panel <NUM> is increased as well.

The left-side rear frame 111A and the right-side rear frame 111B are arranged at a lower position than the trunk-space-side floor panel <NUM>. As illustrated in <FIG>, a rear portion of the left-side rear frame 111A is fixed to the upper portion of the rear-wheel suspension support member 110A, in other words, the left-side load input portion 110a. The left-side rear frame 111A is tilted in a side view such that the left-side rear frame 111A is positioned farther on the lower side at a position farther on the front side from the upper portion of the rear-wheel suspension support member 110A toward the front side, and is also tilted in a plan view such that the left-side rear frame 111A is positioned closer to a vehicle width direction central portion at a position farther on the front side as illustrated in <FIG>. A rear portion of the right-side rear frame 111B is fixed to the upper portion of the rear-wheel suspension support member 110B, in other words, the right-side load input portion 110b. The right-side rear frame 111B is tilted in a side view such that the right-side rear frame 111B is positioned farther on the lower side at a position farther on the front side from the upper portion of the rear-wheel suspension support member 110B toward the front side, and is also tilted in a plan view such that the right-side rear frame 111B is positioned closer to the vehicle width direction central portion at a position farther on the front side as illustrated in <FIG>. Accordingly, the left-side rear frame 111A and the right-side rear frame 111B are each arranged such that the rear frame is positioned on a vehicle-width-direction outer side at a position farther on the rear side, and the interval between the left-side rear frame 111A and the right-side rear frame 111B is smaller at a position farther on the front side.

The rear portion of the left-side rear frame 111A is also connected to the front-rear direction intermediate portion of the left-side rear-side frame 112A. Accordingly, the left-side rear frame 111A serves as a left-side connection frame extending from the rear portion of the center frame <NUM> to the left-side rear-side frame 112A and connecting the rear portion of the center frame <NUM> and the left-side rear-side frame 112A. The left-side rear frame 111A also serves as a left-side rear connection frame connecting the left-side load input portion 110a and the rear-portion cross member 44E. Specifically, a front portion of the left-side rear frame 111A is fixed to the left-side load input portion 110a, and the rear portion of the left-side rear frame 111A is also fixed to the rear-portion cross member 44E.

The rear portion of the right-side rear frame 111B is also connected to the front-rear direction intermediate portion of the right-side rear-side frame 112B. Accordingly, the right-side rear frame 111B serves as a right-side connection frame extending from the rear portion of the center frame <NUM> to the right-side rear-side frame 112B and connecting the rear portion of the center frame <NUM> and the right-side rear-side frame 112B. The right-side rear frame 111B also serves as a right-side rear connection frame connecting the right-side load input portion 110b and the rear-portion cross member 44E. Specifically, a front portion of the right-side rear frame 111B is fixed to the right-side load input portion 110b, and the rear portion of the right-side rear frame 111B is also fixed to the rear-portion cross member 44E.

The left-side rear frame 111A is arranged at an upward tilt toward the left-side load input portion 110a. Accordingly, an upward load from the rear suspension device SP3 is input to the left-side rear frame 111A in a pulling direction, and thus deflection deformation of the left-side rear frame 111A is unlikely to occur as compared to a case in which a load in a compression direction is input, which leads to suppression of vibration and noise due to load input from the rear suspension device SP3. This is same for the right-side rear frame 111B.

The left-side rear frame 111A is arranged on the front side of the left rear drive shaft S2. The left rear drive shaft S2 is arranged such that the left rear drive shaft S2 overlaps with part of the left-side rear frame 111A when viewed in the front-rear direction. Specifically, the height of a right-left direction intermediate portion of the left rear drive shaft S2 is substantially equal to the height of a part between the front and rear portions of the left-side rear frame 111A.

The right-side rear frame 111B is arranged on the front side of the right rear drive shaft S2. The right rear drive shaft S2 is arranged such that the right rear drive shaft S2 overlaps with part of the right-side rear frame 111B when viewed in the front-rear direction. Specifically, the height of a right-left direction intermediate portion of the right rear drive shaft S2 is substantially equal to the height of a part between the front and rear portions of the right-side rear frame 111B.

As illustrated in <FIG> and <FIG>, the occupant-space-side floor panel <NUM> includes a front-portion cross member 44A, an intermediate cross member 44B, a recessed-portion front-side cross member 44C, a recessed-portion rear-side cross member 44D, and the rear-portion cross member 44E. The front-portion cross member 44A, the intermediate cross member 44B, the recessed-portion front-side cross member 44C, the recessed-portion rear-side cross member 44D, and the rear-portion cross member 44E extend in the right-left direction and are fixed to the upper surface of the occupant-space-side floor panel <NUM>. Thus, the front-portion cross member 44A, the intermediate cross member 44B, the recessed-portion front-side cross member 44C, the recessed-portion rear-side cross member 44D, and the rear-portion cross member 44E are disposed such that the members intersect with the center frame <NUM>, which will be described later, in a plan view in the occupant space R1.

The front-portion cross member 44A is disposed at the front portion of the occupant-space-side floor panel <NUM>. A front portion of the front-portion cross member 44A is also joined to the lower portion of the dash panel <NUM>. The intermediate cross member 44B is disposed on the rear side of the front-portion cross member 44A and on the front side of the recessed portion 41a, and a closed cross-section is constituted by the intermediate cross member 44B and the occupant-space-side floor panel <NUM>. The rear-portion cross member 44E is disposed at the rear portion of the occupant-space-side floor panel <NUM>. The rear-portion cross member 44E is also fixed to the connection panel <NUM>.

The recessed-portion front-side cross member 44C is disposed extending in the right-left direction along the front portion of the recessed portion 41a on the rear side of the intermediate cross member 44B. The recessed-portion rear-side cross member 44D is disposed extending in the right-left direction along a rear portion of the recessed portion 41a on the rear side of the recessed-portion front-side cross member 44C. A closed cross-section is constituted by the recessed-portion front-side cross member 44C and the occupant-space-side floor panel <NUM>, and a closed cross-section is constituted by the recessed-portion rear-side cross member 44D and the occupant-space-side floor panel <NUM>. Since the recessed-portion front-side cross member 44C and the recessed-portion rear-side cross member 44D are provided, the part at which the recessed portion 41a is formed can be reinforced. A front portion of the floor frame 41c provided inside the recessed portion 41a is connected to a right-left direction central portion of the recessed-portion front-side cross member 44C, and a rear portion of the floor frame 41c is connected to a right-left direction central portion of the recessed-portion rear-side cross member 44D.

As illustrated in <FIG>, the upper-portion structural body <NUM> includes a pair of right and left left-side seat rails <NUM> supporting the left-side front seat FS, and a pair of right and left right-side seat rails <NUM> supporting the right-side front seat FS. The left-side seat rails <NUM> are used to adjust the position of the left-side front seat FS in the front-rear direction, are disposed on the left side on the occupant-space-side floor panel <NUM>, and extend in the front-rear direction. The right-side seat rails <NUM> are used to adjust the position of the right-side front seat FS in the front-rear direction, are disposed on the right side of the occupant-space-side floor panel <NUM>, and extend in the front-rear direction.

The left-side seat rails <NUM> are positioned higher than the intermediate cross member 44B and the recessed-portion front-side cross member 44C and attached to the intermediate cross member 44B and the recessed-portion front-side cross member 44C. Specifically, as illustrated in <FIG> as well, the left-side seat rails <NUM> extend from the intermediate cross member 44B to the recessed-portion front-side cross member 44C, front portions of the left-side seat rails <NUM> are attached to the intermediate cross member 44B, and rear portions of the left-side seat rails <NUM> are attached to the recessed-portion front-side cross member 44C.

Similarly, the right-side seat rails <NUM> extend from the intermediate cross member 44B to the recessed-portion front-side cross member 44C, front portions of the right-side seat rails <NUM> are attached to the intermediate cross member 44B, and rear portions of the right-side seat rails <NUM> are attached to the recessed-portion front-side cross member 44C.

As illustrated in <FIG>, the intermediate cross member 44B includes a front-portion common bracket <NUM> to which the front portions of the left-side seat rails <NUM> and the front portions of the right-side seat rails <NUM> are attached in a state in which the seat rails are separated from each other in the right-left direction. Note that the center frame <NUM> is omitted in <FIG>. As illustrated in <FIG>, the front-portion common bracket <NUM> has a shape that is long in the right-left direction and is fixed to an upper surface of the intermediate cross member 44B. A right-left direction central portion of the front-portion common bracket <NUM> is positioned at a right-left direction central portion of the intermediate cross member 44B. A central fixation portion 45a (illustrated only in <FIG> and <FIG>) into which a lower portion of a second connecting member <NUM> to be described later is inserted is provided at the right-left direction central portion of the front-portion common bracket <NUM>. A left-side fixation portion 45b (illustrated only in <FIG> and <FIG>) to which the front portions of the left-side seat rails <NUM> are fixed by fastening members (not illustrated) such as bolts or screws is provided on the left side of the central fixation portion 45a of the front-portion common bracket <NUM>. A right-side fixation portion 45c (illustrated only in <FIG> and <FIG>) to which the front portions of the right-side seat rails <NUM> are fixed by fastening members (not illustrated) is provided on the right side of the central fixation portion 45a of the front-portion common bracket <NUM>. Note that the seat rails are omitted in <FIG> and <FIG>.

The recessed-portion front-side cross member 44C includes a rear-portion common bracket <NUM> to which the rear portions of the left-side seat rails <NUM> and the rear portions of the right-side seat rails <NUM> are attached in a state in which the seat rails are separated from each other in the right-left direction. As illustrated in <FIG>, the rear-portion common bracket <NUM> has a shape that is long in the right-left direction and is fixed to an upper surface of the recessed-portion front-side cross member 44C. A right-left direction central portion of the rear-portion common bracket <NUM> is positioned at the right-left direction central portion of the recessed-portion front-side cross member 44C. A central fixation portion 46a (illustrated only in <FIG> and <FIG>) in which a lower portion of a connecting member to be described later is inserted and fixed is provided at the right-left direction central portion of the rear-portion common bracket <NUM>. A left-side fixation portion 46b (illustrated only in <FIG> and <FIG>) to which the rear portions of the left-side seat rails <NUM> are fixed by fastening members (not illustrated) is provided on the left side of the central fixation portion 46a of the rear-portion common bracket <NUM>. A right-side fixation portion 46c (illustrated only in <FIG> and <FIG>) to which the rear portions of the right-side seat rails <NUM> are fixed by fastening members (not illustrated) is provided on the right side of the central fixation portion 46a of the rear-portion common bracket <NUM>.

As illustrated in, for example, <FIG>, the upper-portion structural body <NUM> includes the center frame <NUM> that is continuous from the dash panel <NUM> to the connection panel <NUM>. The center frame <NUM> is positioned at a right-left direction central portion, and also the front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> of the battery unit Y are positioned at the right-left direction central portion. Specifically, the disposition positions of the front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> and the center frame <NUM> are set to have a positional relation in which the front-portion central member <NUM> and the first to third rear-portion central members <NUM> to <NUM> each overlaps with the center frame <NUM> in a plan view.

The center frame <NUM> is disposed to be higher than and away from the occupant-space-side floor panel <NUM> at a right-left direction central portion of the occupant space R1 and extends in the front-rear direction. The distance between a lower surface of the center frame <NUM> and the upper surface of the occupant-space-side floor panel <NUM> may be set to be, for example, equal to or larger than <NUM> or equal to or larger than <NUM> at a part separated most. The left-side front seat FS and a rear seat RS are disposed on the left side of the center frame <NUM>, and the right-side front seat FS and a rear seat RS are disposed on the right side of the center frame <NUM>.

Since at least a front-side part of the center frame <NUM> is arranged to be higher than and away from the occupant-space-side floor panel <NUM>, components and the like can be disposed between at least a lower surface of the front-side part of the center frame <NUM> and the upper surface of the occupant-space-side floor panel <NUM>. Alternatively, the space between the lower surface of the center frame <NUM> and the upper surface of the occupant-space-side floor panel <NUM> can be used as an object housing unit. As illustrated in <FIG> and <FIG>, the center frame <NUM> according to the present embodiment includes a bend portion 80A that bends in the up-down direction at a front-rear direction intermediate portion, but the center frame <NUM> may be omitted. When the bend portion 80A is omitted, the center frame <NUM> has a shape that extends straight.

Since the bend portion 80A is provided in the center frame <NUM>, for example, a rear-side part of the center frame <NUM> can be positioned lower than a front-side part of the center frame <NUM>, and thus comfortability of rear-seat passengers can be improved. Since the front-side part of the center frame <NUM> can be positioned higher than the rear-side part of the center frame <NUM>, a large-sized component or object, a plurality of components, or the like can be arranged at a lower position than the front-side part of the center frame <NUM>. The bend portion 80A is formed at a site on the front side of a front-rear direction central portion of the center frame <NUM>. The formation position of the bend portion 80A is not limited to the illustrated position but may be, for example, the front-rear direction central portion of the center frame <NUM> or a site on the rear side of the front-rear direction central portion of the center frame <NUM>.

Specifically, the center frame <NUM> includes a front-side frame member <NUM> extending in the front-rear direction, a rear-side frame member <NUM> disposed on the vehicle rear side of the front-side frame member <NUM> and extending toward the rear side, and a connection member <NUM> connecting a rear portion of the front-side frame member <NUM> and a front portion of the rear-side frame member <NUM>. The front-side frame member <NUM> and the rear-side frame member <NUM> have hollow shapes, in other words, tubular shapes extending in the front-rear direction and may be formed of, for example, an extruded material. The front-side frame member <NUM> and the rear-side frame member <NUM> having hollow shapes are lightweight and high-stiffness members. When the center frame <NUM> is used as an air sending means of air-conditioned air to be described later, a rear portion of the rear-side frame member <NUM> may be blocked to prevent leakage of air-conditioned air.

Vertical cross-sections of the front-side frame member <NUM> and the rear-side frame member <NUM> in the vehicle width direction have rectangular shapes, and thus the front-side frame member <NUM> and the rear-side frame member <NUM> each include an upper wall portion and a lower wall portion extending in the right-left direction and right and left sidewall portions extending in the up-down direction. Note that the cross-sectional shapes of the front-side frame member <NUM> and the rear-side frame member <NUM> are not limited to rectangular shapes but may be pentagonal shapes or higher polygonal shapes or may be circular shapes or elliptical shapes.

The dimension of the rear-side frame member <NUM> in the longitudinal direction is set to be longer than the dimension of the front-side frame member <NUM> in the longitudinal direction. Accordingly, a connection part between the front-side frame member <NUM> and the rear-side frame member <NUM> is positioned on the front side of a front-rear direction central portion of the occupant space R1. Note that the center frame <NUM> is not limited to the two-division structure of the front-side frame member <NUM> and the rear-side frame member <NUM> but may be formed as one member a front portion to a rear portion or may have a three-division structure.

The front-side frame member <NUM> is tilted at a first tilt angle relative to a horizontal plane and extends straight. The rear-side frame member <NUM> is tilted at a second tilt angle smaller than the first tilt angle relative to the horizontal plane and extends straight. Since the rear-side frame member <NUM> is tilted at a tilt angle different from that of the front-side frame member <NUM>, the bend portion 80A that bends downward is formed at the connection part between the front-side frame member <NUM> and the rear-side frame member <NUM>. In the present embodiment, the rear-side frame member <NUM> is arranged at a downward tilt toward the rear side. Note that the front-side frame member <NUM> and the rear-side frame member <NUM> may have the same tilt angle and may be tilted downward toward the rear side. In this case, no bend portion 80A is formed.

As illustrated in <FIG> and <FIG>, inside the rear-side frame member <NUM>, a first partition wall portion 82a for partitioning the inner space into an upper path and a lower path is provided extending in the vehicle width direction and the front-rear direction. In addition, inside the rear-side frame member <NUM>, a second partition wall portion 82b for separating a left path on the vehicle-width-direction left side from a right path on the vehicle-width-direction right side is provided extending in the up-down direction and the front-rear direction. The first partition wall portion 82a and the second partition wall portion 82b are integrally formed. Four paths, namely, an upper-left path T11, an upper-right path T12, a lower-left path T13, and a lower-right path T14 are formed inside the rear-side frame member <NUM> by the first partition wall portion 82a and the second partition wall portion 82b. The first partition wall portion 82a and the second partition wall portion 82b function as ribs provided inside the center frame <NUM>. Note that the first partition wall portion 82a and the second partition wall portion 82b may be provided as necessary, and one or both thereof may be omitted. Three partition wall portions or more may be provided.

Inside the front-side frame member <NUM>, similarly to the inside of the rear-side frame member <NUM>, a first partition wall portion 81a is provided extending in the vehicle width direction and the front-rear direction, and an inner space of the front-side frame member <NUM> is divided into an upper path and a lower path by the first partition wall portion 81a. In addition, a second partition wall portion 81b that separates a left path on the vehicle-width-direction left side from a right path on the vehicle-width-direction right side is provided inside the front-side frame member <NUM>. Similarly to the rear-side frame member <NUM>, an upper-left path T11, an upper-right path T12, a lower-left path T13, and a lower-right path T14 are formed inside the front-side frame member <NUM> by the first partition wall portion 81a and the second partition wall portion 81b.

As illustrated in <FIG>, the connection member <NUM> has a tubular shape connecting the rear portion of the front-side frame member <NUM> and the front portion of the rear-side frame member <NUM> to allow communication therebetween, and the rear portion of the front-side frame member <NUM> and the front portion of the rear-side frame member <NUM> are connected in a state of being inserted in the connection member <NUM>. Specifically, the connection member <NUM> includes an upper wall portion 83a and a lower wall portion 83b extending in the right-left direction and a left wall portion 83c and a right wall portion 83d extending in the up-down direction. The upper wall portion 83a extends from an upper portion of the left wall portion 83c to an upper portion of the right wall portion 83d, and the lower wall portion 83b extends from a lower portion of the left wall portion 83c to a lower portion of the right wall portion 83d. The dimension of the lower wall portion 83b of the connection member <NUM> in the front-rear direction is set to be longer than the dimension of the upper wall portion 83a in the front-rear direction. The dimensions of the left wall portion 83c and the right wall portion 83d in the front-rear direction are longer at a lower position in accordance with the difference between the dimensions of the upper wall portion 83a and the lower wall portion 83b in the front-rear direction.

A first connection wall portion 83e extending in the right-left direction from an up-down direction intermediate portion of the left wall portion 83c to an up-down direction intermediate portion of the right wall portion 83d and a second connection wall portion 83f extending from a right-left direction intermediate portion of the upper wall portion 83a to a right-left direction intermediate portion of the lower wall portion 83b are provided inside the connection member <NUM>. The first connection wall portion 83e and the second connection wall portion 83f are integrally formed with the upper wall portion 83a, the lower wall portion 83b, the left wall portion 83c, and the right wall portion 83d.

A front-side cutout portion <NUM> into which the rear portion of the front-side frame member <NUM> is inserted is formed on the front side of the second connection wall portion 83f. A rear-side cutout portion <NUM> into which the front portion of the rear-side frame member <NUM> is inserted is formed on the rear side of the second connection wall portion 83f. When the front-side frame member <NUM> and the rear-side frame member <NUM> are connected to each other through the connection member <NUM>, the upper-left path T11, the upper-right path T12, the lower-left path T13, and the lower-right path T14 of the front-side frame member <NUM> communicate with the upper-left path T11, the upper-right path T12, the lower-left path T13, and the lower-right path T14, respectively, of the rear-side frame member <NUM>.

The bend portion 80A may be provided without the connection member <NUM>. In this case, the bend portion 80A of the center frame <NUM> can be formed through bending fabrication of the center frame <NUM>. For example, the bending fabrication may be simultaneously provided when the center frame <NUM> is fabricated by extrusion, or the bending fabrication may be provided after the extrusion fabrication.

As illustrated in <FIG>, the upper-portion structural body <NUM> includes an air-conditioning device <NUM> that generates air-conditioned air to be sent to the occupant space R1. The air-conditioning device <NUM> is disposed on the front side of a front portion of the front-side frame member <NUM> and positioned on the front side of the center frame <NUM>. The air-conditioning device <NUM> will be described later in detail.

As illustrated in <FIG>, the center frame <NUM> includes a left-side frame member 84A and a right-side frame member 84B constituting the front portion of the center frame <NUM>, and accordingly, the front portion of the center frame <NUM> has a shape bifurcated in the right-left direction. The left-side frame member 84A and the right-side frame member 84B are provided at an interval from each other in the right-left direction. A rear portion of the left-side frame member 84A is fixed to a left-side surface of a front-rear direction intermediate portion of the front-side frame member <NUM>. The left-side frame member 84A is tilted from a fixation part to the front-side frame member <NUM> toward the front side in a plan view such that the left-side frame member 84A is positioned farther on the left side at a position farther on the front side. A front portion of the left-side frame member 84A is connected to a part of the dash panel <NUM> higher than and away from the occupant-space-side floor panel <NUM>. A rear portion of the left-side front frame 54A is connected to the front portion of the left-side frame member 84A. Specifically, as illustrated in <FIG>, the rear portion of the left-side front frame 54A includes a left-side connection portion 54a. The left-side connection portion 54a is a member for connecting the left-side front frame 54A to the front portion of the left-side frame member 84A and is fixed to the dash panel <NUM>. A front portion of the left-side front frame 54A extends to the left-side front-wheel suspension support member 51A and is fixed to the left-side front-wheel suspension support member 51A.

A rear portion of the right-side frame member 84B is fixed to a right-side surface of the front-rear direction intermediate portion of the front-side frame member <NUM>. The right-side frame member 84B is tilted from a fixation part to the front-side frame member <NUM> toward the front side in a plan view such that the right-side frame member 84B is positioned farther on the right side at a position farther on the front side. A front portion of the right-side frame member 84B is connected to the part of the dash panel <NUM> higher than and away from the occupant-space-side floor panel <NUM>. A rear portion of the right-side front frame 54B (illustrated in <FIG>) is connected to the front portion of the right-side frame member 84B. Specifically, the rear portion of the right-side front frame 54B includes a right-side connection portion 54b as illustrated in <FIG>. The right-side connection portion 54b is a member for connecting the right-side front frame 54B to the front portion of the right-side frame member 84B and is fixed to the dash panel <NUM>. A front portion of the right-side front frame 54B extends to the right-side front-wheel suspension support member 51B and is fixed to the right-side front-wheel suspension support member 51B.

The upper-portion structural body <NUM> includes a plurality of connecting members <NUM> to <NUM>. The connecting members <NUM> to <NUM> are members for connecting the center frame <NUM> to the occupant-space-side floor panel <NUM>, each member extending upward from the occupant-space-side floor panel <NUM> and having an upper portion fixed to the center frame <NUM>. The connecting members <NUM> to <NUM> include the first connecting member <NUM>, the second connecting member <NUM>, and the third connecting member <NUM> and are each formed of, for example, an extruded material. The number of connecting members <NUM> to <NUM> is not limited to plurality but may be one.

Among the first to third connecting members <NUM> to <NUM>, the first connecting member <NUM> is disposed farthest on the front side in the occupant space R1, and the first connecting member <NUM> is separated on the rear side from the dash panel <NUM>. A lower portion of the first connecting member <NUM> is fixed to a site separated on the rear side from the dash panel <NUM> on the occupant-space-side floor panel <NUM>, and an upper portion of the first connecting member <NUM> is fixed to a site separated on the rear side from the dash panel <NUM> on the center frame <NUM>. Accordingly, a closed cross-section structure is constituted in a side view by the center frame <NUM>, the first connecting member <NUM>, the occupant-space-side floor panel <NUM>, and the dash panel <NUM>. Specifically, the center frame <NUM>, the first connecting member <NUM>, the occupant-space-side floor panel <NUM>, and the dash panel <NUM> are connected to form an annular structure.

As illustrated in, for example, <FIG>, the second connecting member <NUM> is separately disposed on the rear side of the first connecting member <NUM>. The lower portion of the first connecting member <NUM> and a lower portion of the second connecting member <NUM> are fixed to sites separated from each other in the front-rear direction on the occupant-space-side floor panel <NUM>. The upper portion of the first connecting member <NUM> and an upper portion of the second connecting member <NUM> are fixed to sites separated from each other in the front-rear direction of the center frame <NUM>. Accordingly, a closed cross-section structure is constituted in a side view by the center frame <NUM>, the first connecting member <NUM>, the occupant-space-side floor panel <NUM>, and the second connecting member <NUM>. The third connecting member <NUM> is separately disposed on the rear side of the second connecting member <NUM>.

As illustrated in <FIG>, the first connecting member <NUM> includes a left-side member (left-side connecting member) 101A and a right-side member (right-side connecting member) 101B. Lower portions of the left-side member 101A and the right-side member 101B are fixed to the front-portion cross member 44A but may be directly fixed to a body part of the occupant-space-side floor panel <NUM>. The left-side member 101A extends at a tilt in a front view such that the left-side member 101A is positioned farther on the left side at a position farther on the upper side from the front-portion cross member 44A. An upper portion of the left-side member 101A is fixed to the front portion of the left-side frame member 84A of the center frame <NUM>. The upper portion of the left-side member 101A may be fixed to the left-side connection portion 54a. In this case, the left-side member 101A connects the left-side connection portion 54a and the occupant-space-side floor panel <NUM>.

The right-side member 101B extends at a tilt in a front view such that the right-side member 101B is positioned farther on the right side at a position farther on the upper side from the front-portion cross member 44A. An upper portion of the right-side member 101B is fixed to the front portion of the right-side frame member 84B of the center frame <NUM>. The upper portion of the right-side member 101B may be fixed to the right-side connection portion 54b. In this case, the right-side member 101B connects the right-side connection portion 54b and the occupant-space-side floor panel <NUM>. Since the front portion of the left-side frame member 84A and the front portion of the right-side frame member 84B are separated from each other in the right-left direction, most parts of the left-side member 101A and the right-side member 101B except for the lower portions thereof are separated from each other in the right-left direction, and accordingly, the interval between the left-side member 101A and the right-side member 101B in the right-left direction is larger at a position farther on the upper side.

Although not illustrated, the first connecting member <NUM> may connect the rear portion of the left-side front frame 54A to the occupant-space-side floor panel <NUM>. In this case, the upper portion of the left-side member 101A of the first connecting member <NUM> is fixed to the rear portion of the left-side front frame 54A, and the lower portion of the left-side member 101A is fixed to the occupant-space-side floor panel <NUM>. The first connecting member <NUM> may connect the rear portion of the right-side front frame 54B to the occupant-space-side floor panel <NUM>. In this case, the upper portion of the right-side member 101B of the first connecting member <NUM> is fixed to the rear portion of the right-side front frame 54B, and the lower portion of the right-side member 101B is fixed to the occupant-space-side floor panel <NUM>.

The dimension of the second connecting member <NUM> in the right-left direction is set to be longer than the dimension thereof in the front-rear direction and equal to or smaller than the dimension of the center frame <NUM> in the right-left direction. Accordingly, right and left sides of the second connecting member <NUM> do not protrude from the center frame <NUM> in the right-left direction. A cross-section of the second connecting member <NUM> is set to be larger than a cross-section of the left-side member 101A or the right-side member 101B.

The lower portion of the second connecting member <NUM> is fixed between the left-side seat rails <NUM> and the right-side seat rails <NUM> at the front-portion common bracket <NUM> included in the intermediate cross member 44B. Specifically, the lower portion of the second connecting member <NUM> is fixed in a state of being inserted in the central fixation portion 45a provided at the right-left direction central portion of the front-portion common bracket <NUM>. Thus, the common bracket <NUM> to which the left-side seat rails <NUM> and the right-side seat rails <NUM> are attached becomes a member having a high strength, and in addition, the dimension thereof in the vehicle width direction is long to some extent, and accordingly, a large range of fixation to a body part of the cross member 44B is obtained and fixation strength increases. When the lower portion of the second connecting member <NUM> is fixed to the common bracket <NUM> having a high strength and a high fixation strength in this manner, the strength of connection of the center frame <NUM> by the second connecting member <NUM> is further increased. Note that the lower portion of the second connecting member <NUM> may be directly fixed to the body part of the occupant-space-side floor panel <NUM> or may be directly fixed to the intermediate cross member 44B.

The upper portion of the second connecting member <NUM> is fixed to the bend portion 80A of the center frame <NUM>. Specifically, the upper portion of the second connecting member <NUM> is fixed to the lower wall portion 83b of the connection member <NUM>. Accordingly, the second connecting member <NUM> extends from the bend portion 80A of the center frame <NUM> toward the occupant-space-side floor panel <NUM>. Since the dimension of the lower wall portion 83b of the connection member <NUM> in the front-rear direction is longer than the dimension of the upper wall portion 83a in the front-rear direction, a large area of joint to the second connecting member <NUM> is obtained. When the connection member <NUM> is omitted, the upper portion of the second connecting member <NUM> may be directly fixed to the center frame <NUM>.

Similarly to the second connecting member <NUM>, the third connecting member <NUM> has a cross-section that is long in the right-left direction. A lower portion of the third connecting member <NUM> is fixed to the recessed-portion front-side cross member 44C. An upper portion of the third connecting member <NUM> is fixed to the lower wall portion of the rear-side frame member <NUM> of the center frame <NUM>. As illustrated in <FIG> as well, the third connecting member <NUM> is also fixed to the front portion of the floor frame 41c.

As illustrated in <FIG>, the rear portion of the center frame <NUM> is connected to the connection panel <NUM> and the rear-portion cross member 44E. Specifically, a rear-portion connecting member <NUM> is fixed to the rear portion of the center frame <NUM>, and a right-left direction central portion of the rear-portion cross member 44E is fixed to a lower portion of the rear-portion connecting member <NUM>. The rear portion of the center frame <NUM> and the rear-portion cross member 44E are connected to each other through the rear-portion connecting member <NUM>.

The rear side of the rear-portion connecting member <NUM> is fixed to the connection panel <NUM>. Accordingly, the rear portion of the center frame <NUM> is also connected to the connection panel <NUM> through the rear-portion connecting member <NUM>. The lower portion of the rear-portion connecting member <NUM> is also fixed to the rear portion of the occupant-space-side floor panel <NUM>. In other words, the dash panel <NUM> and the connection panel <NUM> are connected to each other through the center frame <NUM>. In this case, since the center frame <NUM> is positioned higher than and away from the occupant-space-side floor panel <NUM>, the occupant-space-side floor panel <NUM>, the dash panel <NUM>, the connection panel <NUM>, and the center frame <NUM> integrate and constitute a closed cross-section structure in a side view. Accordingly, the distortion stiffness of the vehicle body is sufficiently improved although the occupant-space-side floor panel <NUM> of a floor tunnel-less structure is included.

In addition, the front portion of the left-side rear frame 111A and the front portion of the right-side rear frame 111B are fixed to the lower portion of the rear-portion connecting member <NUM>. Thus, the rear portion of the center frame <NUM> and the left-side rear-wheel suspension support member 110A are connected to each other through the left-side rear frame 111A, and the rear portion of the center frame <NUM> and the right-side rear-wheel suspension support member 110B are connected to each other through the right-side rear frame 111B. Accordingly, the stiffness of the rear-wheel suspension support members 110A and 110B can be increased, which improves maneuvering stability of the vehicle. In addition, the stiffness of the vehicle rear side including the connection panel <NUM> and the vicinity thereof is increased as well.

As illustrated in <FIG>, the traveling motor M included in the rear-side powertrain PT is supported to each rear support frame <NUM> through the non-illustrated mounting member or the like and is disposed on the vehicle rear side of the rear portion of the center frame <NUM>. The attachment height of the rear-side traveling motor M can be optionally set in accordance with the height of attachment to each rear support frame <NUM>. In the present embodiment, the attachment height of the rear-side traveling motor M is set so that the barycenter of the rear-side traveling motor M is positioned at a lower position than an upper end of the rear portion of the center frame <NUM> and higher than a lower end of the rear portion of the center frame <NUM>. In addition, the height of a rotation center of the rear-side traveling motor M, in other words, the height of an up-down direction central portion of the traveling motor M is set to be lower than that of the rear portion of the center frame <NUM>. Since the rear-side powertrain PT is arranged in this manner, for example, a load toward the vehicle front side is applied to the rear portion of the center frame <NUM> when an impact load applied from the vehicle rear side is input to the traveling motor M and the traveling motor M is about to move toward the vehicle front side. In this case, since the rear portion of the center frame <NUM> is connected to the rear-portion cross member 44E, the connection panel <NUM>, and the like and integrated with the occupant-space-side floor panel <NUM>, the movement of the traveling motor M toward the front side is prevented by the center frame <NUM>. The movement of the traveling motor M toward the front side is also prevented by the occupant-space-side floor panel <NUM> and the rear-portion cross member 44E.

The air-conditioning device <NUM> includes a cooler (heat exchanger) <NUM> through which air-conditioned air passes, and an air conditioning casing <NUM> in which the cooler <NUM> is housed. The cooler <NUM> is a cooling heat exchanger including, for example, an evaporator for cooling air-conditioned air. The cooler <NUM> is not limited thereto, but a heating heat exchanger including a heater core or condenser that heats air-conditioned air may be used in place of the cooler <NUM>, and a cooler may be disposed at another part. The cooler <NUM> of the present embodiment is disposed on the front side of the dash panel <NUM>. Note that, although not illustrated, a compressor that compresses a coolant, an expansion valve that depressurizes the coolant, and the like constitute part of the air-conditioning device <NUM>.

For example, when the automobile <NUM> collides on the front side and an impact load toward the rear side is applied to the powertrain PT, the powertrain PT starts retracting depending on the magnitude of the impact load. Since the front-side powertrain PT is arranged as described above, the center frame <NUM> extending in the front-rear direction is arranged on the rear side of the powertrain PT in a state of being connected to the occupant-space-side floor panel <NUM> through the connecting members <NUM> to <NUM>. Accordingly, the retraction of the powertrain PT is suppressed by the center frame <NUM> and the connecting members <NUM> to <NUM>. Since the occupant-space-side floor panel <NUM> is also positioned on the rear side of the powertrain PT, the retraction of the powertrain PT is suppressed by the occupant-space-side floor panel <NUM> as well in some cases.

Subsequently, a specific exemplary configuration of the air-conditioning device <NUM> will be described below. In addition to the above-described cooler <NUM>, a non-illustrated heater, an air mix damper 122a for generating air-conditioned air at a desired temperature by changing the mixed ratio of cool air having passed through the cooler <NUM> and warm air having passed through the heater, and a vent direction switching damper 122b for distributing the generated air-conditioned air of the desired temperature to each component of a vehicle cabin are housed inside the air conditioning casing <NUM> of the air-conditioning device <NUM>. Through operation of the vent direction switching dampers 122b, the air-conditioned air can be supplied to the inner surface of a front window glass FG (illustrated in <FIG>), supplied to the upper body of a passenger, and supplied to the vicinity of the feet of a passenger. The operation of the vent direction switching damper 122b has been conventionally well known.

A front-side part of the air conditioning casing <NUM> is a part in which the cooler <NUM> and the air mix damper 122a are housed, and is arranged on the front side of the dash panel <NUM>. A rear-side part of the air conditioning casing <NUM> is a part in which the vent direction switching damper 122b is housed, and is arranged in the occupant space R1 through the dash panel <NUM>. Accordingly, the cooler <NUM> and the air mix damper 122a are positioned closer to the powertrain PT than the vent direction switching damper 122b. Note that the front-side part of the air conditioning casing <NUM> may be arranged on the rear side of the dash panel <NUM>.

The rear-side part of the air conditioning casing <NUM> includes a vent portion 122c having a duct shape through which the air-conditioned air generated inside the air conditioning casing <NUM> is vented out. The air conditioning casing <NUM> also includes an air introducing duct 122d that provides communication between the vent portion 122c and the inside of the center frame <NUM> and through which the air-conditioned air vented out of the vent portion 122c is introduced to the inside of the center frame <NUM>. The air introducing duct 122d is arranged at a higher position than a control device <NUM> to be described later and extends in the front-rear direction. A front portion of the air introducing duct 122d is connected to the vent portion 122c, and a rear portion of the air introducing duct 122d is connected to the front portion of the front-side frame member <NUM> of the center frame <NUM>. Accordingly, the air-conditioned air generated by the air-conditioning device <NUM> is introduced to the inside of the center frame <NUM> through the air introducing duct 122d. The air introducing duct 122d may be a member that constitutes part of the center frame <NUM>.

Since the center frame <NUM> extends in the front-rear direction, the air-conditioned air can be guided to a desired place in the front-rear direction in the occupant space R1. In this case, since the air introducing duct 122d is arranged at a higher position than the control device <NUM> and has a predetermined width in the right-left direction, direct sunlight is interrupted by the air introducing duct 122d as well and further unlikely to reach the control device <NUM>. Moreover, since the center frame <NUM> is used as an air conditioning duct, an air conditioning duct does not need to be redundantly provided and the occupant space R1 can be enlarged as compared to a case in which an air conditioning duct is redundantly provided. Although not illustrated, air sending ports or the like for sending air-conditioned air in the paths T11 to T14 to the upper side and the lower side are provided at upper and lower wall portions of the center frame <NUM>. Note that the air sending ports or the like may be omitted when the center frame <NUM> is not used as an air conditioning duct.

Since the center frame <NUM> has a cross-section that is large enough to improve the distortion stiffness of the vehicle body, air sending noise can be maintained low when the amount of the air-conditioned air circulating inside the center frame <NUM> is increased. In particular, since the center frame <NUM> extends in a substantially straight shape, a path inside the center frame <NUM> has a substantially straight shape as well, and air sending noise can be maintained low for this reason as well. When the center frame <NUM> includes no heat insulation material nor the like, heat of the air-conditioned air circulating inside the center frame <NUM> is transferred to a wall portion of the center frame <NUM> and radiated from the outer surface of the wall portion to the occupant space R1. Accordingly, it is possible to perform desirable air conditioning by using radiation heat. Note that the center frame <NUM> may include a heat insulation material.

The vehicle-body structure A includes the control device <NUM> (illustrated in, for example, <FIG>, <FIG>, and <FIG>) that controls control target units mounted on the automobile <NUM>. Examples of the control target units include the powertrains PT, a brake device, an electric control suspension device, a lighting device, a navigation device, a head-up display device, an audio device, an in-vehicle monitor, and a television. For example, a water jacket through which cooling water circulates is provided as a heat generation measure in the control device <NUM>. An in-vehicle entertainment function (moving image playback function or music playback function) or the like is mounted in some cases, and in such a case as well, the size of the control device <NUM> increases.

The control device <NUM> of the present embodiment is arranged at a lower position than the front portion of the center frame <NUM> in the occupant space R1. As described above, since the height of the front portion of the center frame <NUM> is higher than the rear portion of the center frame <NUM>, the control device <NUM> having a large size can be arranged. As illustrated with a virtual line in <FIG>, an instrument panel IP is arranged at a higher position than the front portion of the center frame <NUM>.

For example, when a case in which an impact load is applied from the front side is assumed, at least part of the impact load is absorbed by the center frame <NUM> and deformation of the vehicle body in the vicinity of the center frame <NUM> is suppressed since the center frame <NUM> extends in the front-rear direction. Accordingly, the control device <NUM> arranged at a lower position than the center frame <NUM> is protected against the impact load from the front side. This is same for an impact load from the rear side. In particular, at least two places of the center frame <NUM> can be solidly connected to the occupant-space-side floor panel <NUM> through the left-side member 101A and the right-side member 101B, and thus protection performance of the control device <NUM> can be increased.

Subsequently, a cooling path will be described below. <FIG> is a diagram illustrating a schematic structure of a cooling path provided in the automobile <NUM>. A path of cooling water as a heat exchange medium is formed in the cooler <NUM>, and the cooling water circulating through the path is cooled through heat exchange with a low-temperature coolant inside the cooler <NUM>. The vehicle-body structure A includes a supply pipe <NUM> for supplying the cooling water cooled by the cooler <NUM> to the water jacket (not illustrated) included in the control device <NUM>, and a discharge pipe <NUM> for discharging the cooling water supplied to the control device <NUM>. The supply pipe <NUM> is provided with a pump P for transferring the cooling water to the control device <NUM>. The cooling water discharged from the discharge pipe <NUM> is cooled through the cooler <NUM> and then taken into the pump P. The control device <NUM> is cooled as the cooling water is circulated in this manner. The cooling water having cooled the control device <NUM> is used to cool the batteries FB and RB, used to cool the traveling motor M, and then returned to the cooler <NUM>. Note that a coolant may be used in place of the cooling water.

As illustrated in <FIG>, the supply pipe <NUM> and the discharge pipe <NUM> extend through the dash panel <NUM> and are disposed between the left-side member 101A and the right-side member 101B. The supply pipe <NUM> and the discharge pipe <NUM> extend in the front-rear direction below the air-conditioning device <NUM>.

As described above, according to the present embodiment, since the rear portion of the center frame <NUM> higher than and away from the occupant-space-side floor panel <NUM> is connected to the occupant-space-side floor panel <NUM>, the distortion stiffness of the vehicle body is sufficiently improved although the occupant-space-side floor panel <NUM> of a floor tunnel-less structure is included. Moreover, since the height of the center frame <NUM> decreases at a position farther on the vehicle rear side, the center frame <NUM> is arranged close to the occupant-space-side floor panel <NUM>. Accordingly, the center frame <NUM> is not positioned on the upper side in the occupant space R1 and is unlikely to affect comfort in the occupant space R1.

Moreover, the traveling motor M of the rear-side powertrain PT is disposed on the rear side of the rear portion of the center frame <NUM>, and the height of the rotation center of the traveling motor M is set to be lower than the upper portion of the rear portion of the center frame <NUM>. Accordingly, when the traveling motor M is mounted on the rear portion, the mount position of the traveling motor M can be lowered to provide a larger occupant space or trunk space. In addition, for example, when an impact load applied from the rear side is input to the traveling motor M and the traveling motor M is about to move toward the front side, a load toward the front side is applied to the rear portion of the center frame <NUM>, thereby preventing movement of the traveling motor M toward the vehicle front side.

The above-described embodiment is merely exemplary in any aspects and not to be interpreted in a restrictive manner. Furthermore, modifications and changes belonging to the scope of the claims are all included in the scope of the present invention.

Claim 1:
A vehicle-body structure (A) for an automobile (<NUM>), the vehicle-body structure (A) comprising:
a floor panel (<NUM>) constituting a floor of an occupant space (R1) suitable for at least one seat (FS, RS) on which a passenger is able to sit; and
a center frame (<NUM>) disposed to be higher than and away from the floor panel (<NUM>) at a vehicle-width-direction central portion of the occupant space (R1) and extending in a vehicle front-rear direction, wherein
the center frame (<NUM>) is arranged at a downward tilt toward a vehicle rear side, and
a rear portion of the center frame (<NUM>) is connected to the floor panel (<NUM>), characterized in that the vehicle-body structure comprising a traveling motor (M) for driving rear wheels of the automobile (<NUM>), wherein
the traveling motor (M) is disposed on a vehicle rear side of the rear portion of the center frame (<NUM>), and
the traveling motor (M) has a barycenter that is set to be lower than an upper end of the rear portion of the center frame (<NUM>) and higher than a lower end of the rear portion of the center frame (<NUM>).