Patent Description:
In recent years, many hybrid vehicles and electric vehicles have been produced and many vehicles have a large-capacity battery for operating a motor as the drive source.

For example, the hybrid vehicle described in patent document <NUM> has the structure in which a battery and an inverter for driving a motor are disposed so as to face each other in the vehicle width direction with a floor tunnel sandwiched therebetween and a harness for connecting the battery to the inverter is disposed so as to straddle the floor tunnel.

The hybrid vehicle described in patent document <NUM> is a vehicle in which the rear wheels serve as drive wheels and has the structure in which two battery packs are disposed so as to face each other in the vehicle width direction with the floor tunnel sandwiched therebetween and the rear portion of the gearbox and the propeller shaft are disposed in the floor tunnel. <CIT> discloses a vehicle structure having to battery packs located on both sides of a floor tunnel. The battery packs are connected to each other via a connection portion which is additionally reinforced by an reinforcement element connected thereto. Other examples of lower structures of a vehicle exhibiting battery units and gearboxes are also disclosed in the documents <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

By the way, at the time of a front collision of the vehicle, the stroke in which the engine and the gearbox move backward is preferably increased as much as possible to absorb the collision load. For this purpose, it is considered that the stroke in which the engine and the gearbox move backward is increased as much as possible by disposing the gearbox with the rear portion thereof present in the floor tunnel so that the gearbox enters the floor tunnel at the time of a front collision of the vehicle.

Here, when the battery units are disposed on the left and right sides of the floor tunnel as in patent documents <NUM> and <NUM>, if the gearbox is disposed with the rear portion thereof present in the floor tunnel, the battery units come closer to the gearbox. For this reason, when the gearbox moves diagonally backward with respect to the vehicle width direction with respect to the vehicle front-rear direction at the time of a front collision of the vehicle, the inner portions in the vehicle width direction of the battery units may come into contact with the gearbox, possibly damaging the battery units.

The technique disclosed herein addresses the problem described above with an object of suppressing damage to the battery units at the time of a front collision of the vehicle even when the gear box is disposed with a part thereof present in the floor tunnel.

To solve the problem described above, according to the technique disclosed herein, there is provided a lower structure of a vehicle in which a rear wheel serves as a drive wheel, the lower structure including a gearbox disposed with at least a portion thereof present in a floor tunnel formed by a tunnel panel, the portion being present on a vehicle rear side of the gearbox; a propeller shaft that extends from the gearbox toward the vehicle rear side, the propeller shaft transmitting power from the gearbox to the rear wheel; and left and right battery units disposed on a vehicle lower side of left and right floor panels, the left and right floor panels being disposed on a vehicle left side and a vehicle right side of the floor tunnel, in which the portion of the gearbox on the vehicle rear side is disposed in proximity to portions on a vehicle front side and a vehicle upper side of the left and right battery units, each of the left and right battery units has an inner side surface portion that extends in a vehicle front-rear direction along each of both side end portions in a vehicle width direction of the floor tunnel, and each of the left and right battery units has an inner protector that covers a front end portion of each of the inner side surface portion from an inner side in the vehicle width direction.

According to this structure, since the portion of the gearbox on the vehicle rear side is present in the floor tunnel, the gearbox enters the floor tunnel at the time of a front collision of the vehicle. The inner side surface portions of the battery units are located at the position of the floor tunnel. In addition, the portion of the gearbox on the vehicle rear side is disposed in proximity to the portions on the vehicle front side and the vehicle upper side of the battery units. Accordingly, the gearbox may come into contact with the inner side surface portions of the battery units at the time of a front collision of the vehicle.

As a measure against this, in the above structure, the inner protector that covers the front end portion of the inner side surface portion is mounted to each of the battery units. This prevents the gearbox from coming into direct contact with the inner side surface portions of the battery units even when the gearbox moves backward so as to approach one of the left and right battery units at the time of a front collision of the vehicle. As a result, damage to the battery units is suppressed.

In the lower structure of a vehicle, each of the inner protectors may have a protection portion that actually covers each of the inner side surface portions, and a vehicle body connection portion to be connected to a vehicle body structural member of the vehicle, and the vehicle body connection portion of the inner protector may have a smaller width in a vehicle front-rear direction than the protection portion.

According to this structure, since the inner protectors are connected to the vehicle body member, the inner protectors also serve as the brackets that mounts the battery units to the vehicle body and supports the battery units. In addition, since the inner protectors are connected to the vehicle body structural member, the vehicle body can receive the collision load input when the gearbox comes into contact with the inner protector. Furthermore, since the vehicle body connection portion of the inner protector has a smaller width in the vehicle front-rear direction than the protection portion, the weight can be reduced. Accordingly, the weight of the vehicle can be reduced while damage to the battery units is suppressed. Furthermore, width of the protection portion in the vehicle front-rear direction may gradually decreases toward its upper side, in particular may be gradually decreased to the width of the vehicle body connection portion.

The vehicle body connection portion may be arranged at the upper end portion of the protection portion. Vehicle body connection portion and the protection portion may be integrally formed and the vehicle body connection portion may be bent in an angle, in particular at a right angle, toward the inner side in the vehicle width direction, in particular towards the floor tunnel.

In the lower structure of a vehicle according to an embodiment, a reinforcing rib is formed on an outer side surface portion in the vehicle width direction of the inner protector.

This structure suppresses damage to the inner protector even when the gearbox comes into contact with the inner protector at the time of a front collision of the vehicle and the collision load is input to the inner protector. As a result, damage to the battery units can be suppressed more effectively.

In the embodiment described above, the reinforcing rib may include a plurality of vertical ribs that extend in an up-down direction.

That is, since the portion of the gearbox on the vehicle rear side is disposed in proximity to the portions on the vehicle front side and the vehicle upper side of the battery units, the gearbox moves backward and moves from the upper side to the lower side at the time of a front collision of the vehicle. Accordingly, the collision load is probably input to the inner protector in the up-down direction. Accordingly, damage to the inner protectors can be effectively suppressed because the reinforcing rib includes the plurality of vertical ribs.

In the embodiment described above, the reinforcing rib includes a horizontal rib that extends in the vehicle front-rear direction, and at least a part of the horizontal ribs is located at the same height as the tunnel panel.

According to this structure, when the collision load in the vehicle width direction is input to the inner protectors, the horizontal ribs come into contact with the tunnel panel, whereby the collision load can be received by the vehicle body. This can prevent the collision load from being transmitted to the battery units and damage to the battery units can be suppressed more effectively.

In the lower structure of a vehicle described above, the inner side surface portion of each of the left and right battery units may have a projecting portion that projects to the inner side in the vehicle width direction, the inner protector may be disposed in a region above the projecting portion of the inner side surface portion, the inner protector being fixed to the projecting portion via a shaft-like fastening member, and the shaft-like fastening member may be fastened so as to extend in the up-down direction.

According to this structure, even when the gearbox comes into contact with the inner protectors and the collision load is input to the inner protectors, the shaft-like fastening portion can appropriately receive the load. This can appropriately prevent the inner protectors from peeling off from the battery units.

The battery units each may comprise a casing including the battery pack. Each casing may be divided in the up-down direction of the vehicle into an upper and lower case. Both cases may comprise a flange extending along their edges. The cases of one battery unit may be connected to each other via the flanges overlapping each other. The mentioned projecting portion of the inner side surface portion of the battery units may be formed by said flanges, in particular the upper flange of the upper case. In this case, the inner protector can be fixed to the upper and lower flange via the shaft-like fastening member.

The inner protector may also comprise two mount portions each adapted to receive one shaft-like fastening member. The mount portions are preferably arranged at the front and rear end portions of the protection portion seen in the front rear direction of the vehicle, in particular at the lower side seen in the up-down direction of the vehicle. Further preferably, some of the vertical ribs may extend into said mount portions.

In the lower structure of a vehicle described above in which the inner side surface portion of each of the left and right battery units has the projecting portion, an inner surface in the vehicle width direction of the inner protector may be located at substantially the same position in the vehicle width direction as an inner end portion in the vehicle width direction of the projecting portion.

According to this structure, it is possible to prevent the battery units from dropping at the time of a front collision of the vehicle because the gearbox is caught by the projecting portion. As a result, damage to the battery units can be suppressed more effectively.

In the lower structure of a vehicle described above, each of the left and right battery units may have a front protector that covers a front end portion of the inner protector from the vehicle front side. Said front protector may also cover an inner portion in the vehicle width direction of the front surface portion of the battery unit from the front side.

According to this structure, it is possible to prevent the inner protectors from peeling off from the battery units because the gearbox is caught by the front end portions of the inner protectors at the time of a front collision of the vehicle. As a result, damage to the battery units can be suppressed more effectively.

In the lower structure of a vehicle described above, the portion of the gearbox on the vehicle rear side may be included in a transfer.

According to this structure, damage to the battery unit can be appropriately suppressed even in, for example, a four-wheel-drive structure.

As described above, according to the technique disclosed herein, even when the gearbox is disposed with a part thereof present in the floor tunnel, damage to the battery units at the time of a front collision of the vehicle can be suppressed.

Exemplary embodiments will be described in detail below with reference to the drawings. In the following description, the front, rear, upper, and lower sides of a vehicle <NUM> are simply referred to as the front, rear, upper, and lower sides, respectively. In addition, the left and the right when the front side is seen from the rear side are simply referred to as the left and the right, respectively.

<FIG> schematically illustrates a drive system of the vehicle <NUM> to which a lower structure according to the embodiment has been applied. <FIG> illustrates in detail the bottom surface of the periphery of a driver seat and a passenger seat of the vehicle <NUM>. <FIG> illustrates the disposition in the vehicle <NUM> as seen from below.

The vehicle <NUM> is a hybrid vehicle and includes an engine <NUM> and a motor <NUM> as drive sources and a transmission <NUM> that changes the speed of a driving force transmitted from at least one of the engine <NUM> and the motor <NUM> and transmits the driving force. The engine <NUM> is vertically mounted substantially in the middle in the vehicle width direction in an engine room formed in the front of a vehicle interior. The motor <NUM> is disposed behind the engine <NUM> with a damper <NUM> sandwiched therebetween. The transmission <NUM> is vertically mounted behind the motor <NUM>.

The vehicle <NUM> is a vehicle having left and right rear wheels <NUM> as the driving wheels. More specifically, the vehicle <NUM> has a four-wheel-drive structure in which both the left and right front wheels <NUM> and the left and right rear wheels <NUM> are driving wheels. The rear portion of the transmission <NUM> is a transfer 4a that transmits the driving force to the front wheels <NUM> and the rear wheels <NUM>. A front propeller shaft <NUM> extends toward the front side from the transfer 4a. A rear propeller shaft <NUM> extends toward the rear side from the transfer 4a. The front propeller shaft <NUM> is disposed slightly to the right of the middle in the vehicle width direction and the rear propeller shaft <NUM> is disposed substantially in the middle in the vehicle width direction. Although not described in detail, the driving force changed in speed by the transmission <NUM> is transmitted to the front propeller shaft <NUM> and the rear propeller shaft <NUM> via the transfer 4a. Then, the driving force is transmitted to the front wheels <NUM> and the rear wheels <NUM> via the front propeller shaft <NUM> and the rear propeller shaft <NUM>, respectively.

As illustrated in <FIG>, the transmission <NUM> is disposed in the floor tunnel <NUM> so as to be inclined to the lower side from the front side toward the rear side. The transfer 4a of the transmission <NUM> is disposed in proximity to the portions on the front side and the upper side of the battery units <NUM> and 40R, which will be described later.

The floor tunnel <NUM> is formed by a tunnel panel <NUM>. As illustrated in <FIG>, the upper end portion of the tunnel panel <NUM> is inclined to the lower side from the front side toward the rear side. Accordingly, the floor tunnel <NUM> is narrower in the up-down direction toward the rear side.

The rear propeller shaft <NUM> is disposed in the floor tunnel <NUM>. The rear propeller shaft <NUM> is connected to the transfer 4a via a rubber cup 4b. The rear propeller shaft <NUM> extends from the position of the rubber cup 4b toward the rear side while being inclined to the lower side. A universal joint 9a is provided at the middle position in the front-rear direction of the rear propeller shaft <NUM>. The rear propeller shaft <NUM> pivots in the up-down direction and the left-right direction due to the universal joint 9a at the time of a front collision.

A rubber cup 9b is provided in front of the universal joint 9a in the rear propeller shaft <NUM>. A support bracket 9c that supports the rear propeller shaft <NUM> is provided at the position of the rubber cup 9b. The support bracket 9c has a U-shape that covers the rubber cup 9b from below and the left and right end portions thereof are connected, with bolts, to an upper tunnel reinforcement <NUM> for reinforcement, which is provided on the tunnel panel <NUM>.

Side tunnel reinforcements <NUM> that extend in the front-rear direction are provided in the left and right end portions of the tunnel panel <NUM>, respectively. The side tunnel reinforcements <NUM> are members for reinforcing the tunnel panel <NUM>. The side tunnel reinforcements <NUM> are connected to the inner portion of the tunnel panel <NUM> by welding so as to form closed cross sections between the side tunnel reinforcements <NUM> and the tunnel panel <NUM>.

A pair of left and right floor panels <NUM> constituting the floor of the vehicle interior are provided on the left and right sides of the tunnel panel <NUM>. The floor panels <NUM> spread horizontally in the front-rear direction and the vehicle width direction (left-right direction). As illustrated in <FIG> and <FIG>, the right end portion of the left floor panel <NUM> is connected to the left end portion of the tunnel panel <NUM> by welding. The left end portion of the right floor panel <NUM> is connected to the right end portion of the tunnel panel <NUM> by welding. The left and right floor panels <NUM> are connected to each other in the left-right direction by the tunnel panel <NUM>. The connection portions between the floor panels <NUM> and the tunnel panel <NUM> are located at the same positions as the connection portions between the tunnel panel <NUM> and the side tunnel reinforcements <NUM> or are located on the outer side in the vehicle width direction of the connection portions between the tunnel panel <NUM> and the side tunnel reinforcements <NUM>.

Left and right toe boards <NUM> are connected to the front end portions of the left and right floor panels <NUM> by welding, respectively. The left and right toe boards <NUM> extend from the front end portions of the left and right floor panels <NUM> toward the front side while being inclined upward. The upper end portions of the left and right toe boards <NUM> are joined to the lower end portion of a dash panel (not illustrated) that separates the vehicle interior from the engine room. The right end portion of the left toe board <NUM> is connected to the left end portion of the tunnel panel <NUM> by welding. The left end portion of the right toe board <NUM> is connected to the right end portion of the tunnel panel <NUM> by welding.

A pair of left and right floor frames <NUM> that extend in the front-rear direction are connected to the lower surfaces of the left and right floor panels <NUM> and the lower surfaces of the left and right toe boards <NUM>, respectively. The left and right floor frames <NUM> extend toward the rear side while being inclined to the outer side in the vehicle width direction so as to be separated from each other in the vehicle width direction, and then extend straight toward the rear side in parallel to each other. As illustrated in <FIG> and <FIG>, the floor frames <NUM> have a U-shaped cross section with the upper side thereof open. The floor frames <NUM> are connected to the lower surfaces of the left and right floor panels <NUM> and the lower surfaces of the left and right toe boards <NUM> by welding so as to form closed cross sections between the floor frames <NUM>, the floor panels <NUM>, and the toe boards <NUM>.

A pair of left and right side sills <NUM> that extend in the front-rear direction are connected to the outer end portions in the vehicle width direction of the left and right floor panels <NUM>. The left and right side sills <NUM> are located on the outer side in the vehicle width direction of the left and right floor frames <NUM>. As illustrated in <FIG> and <FIG>, the left side sill <NUM> is connected to the left end portion of the left floor panel <NUM> by welding. The right side sill <NUM> is connected to the right end portion of the right floor panel <NUM> by welding.

As illustrated in <FIG>, the front end portions of the left and right floor frames <NUM> are connected to the front end portions of the left and right side sills <NUM> via left and right gussets <NUM>, respectively.

As illustrated in <FIG> and <FIG>, on the left and right sides of the floor tunnel in the region behind the transfer 4a, the left and right battery units <NUM> and 40R in which power for driving the motor <NUM> is stored are disposed. The left battery unit <NUM> is disposed below the passenger seat and the right battery unit 40R is disposed below the driver seat. The left and right battery units <NUM> and 40R are electrically connected to each other by a connector. The right end portion of the left battery unit <NUM> and the left end portion of the right battery unit 40R slightly overlap the floor tunnel <NUM> as seen in the up-down direction. The battery units <NUM> and 40R will be described in detail later.

As illustrated in <FIG>, a transmission support member <NUM> that supports the transfer 4a (that is, the transmission <NUM>) is provided slightly in front of the left and right battery units <NUM> and 40R. As illustrated in <FIG>, the transmission support member <NUM> is disposed in proximity to the front surface portions <NUM> and 43R (referred to below as the left front surface portion <NUM> and the right front surface portion 43R) of the battery units <NUM> and 40R so as to face the left front surface portion <NUM> and the right front surface portion 43R. The transmission support member <NUM> has a U-shape that spreads toward the outer side in the vehicle width direction toward the upper side as seen in the front-rear direction. The transmission support member <NUM> is mounted to the vehicle body so as to straddle the floor tunnel <NUM> as seen in the front-rear direction.

The U-shaped portion of the transmission support member <NUM> has a wide shape that spreads in the front-rear direction. The left and right upper end portions of the transmission support member <NUM> are mount portions 33a through which the transmission support member <NUM> is mounted to the vehicle body. As illustrated in <FIG>, the left and right mount portions 33a project to the front side and the rear side of the other portions of the transmission support member <NUM>. The mount portions 33a each have a plurality of (three for each and six in total in this case) holes 33b through which bolts <NUM> pass.

As illustrated in <FIG> and <FIG>, an exhaust pipe <NUM> through which the exhaust gas from the engine <NUM> passes is disposed on the right side of the transmission support member <NUM>. The exhaust pipe <NUM> extends from the engine <NUM> toward the floor tunnel <NUM> through the right side of the transmission <NUM> and the transmission support member <NUM>, passes through the floor tunnel <NUM>, and extends toward the rear side. The exhaust pipe <NUM> has an exhaust gas purification device <NUM> on the right side of the transmission support member <NUM>. The exhaust gas purification device <NUM> has a horizontally long elliptical shape and has an exhaust gas purification catalyst 29a therein. The exhaust pipe <NUM> enters the floor tunnel <NUM> through the space between the front surface portion 43R of the right battery unit 40R and the transmission support member <NUM> at the same height as the front surface portion 43R (more specifically, a right front protector 60R described later) of the right battery unit 40R and the transmission support member <NUM>.

Next, the peripheral structures of the left battery unit <NUM> and the right battery unit 40R will be described in detail.

First, the peripheral structure of the left battery unit <NUM> will be described. As illustrated in <FIG> and <FIG>, the left battery unit <NUM> has a box shape and is substantially rectangular in bottom view. The left battery unit <NUM> includes the left front surface portion <NUM>, a left outer side surface portion <NUM> that extends in the front-rear direction from the outer end portion in the vehicle width direction of the left front surface portion <NUM>, a left inner side surface portion <NUM> that extends in the front-rear direction from the inner end portion in the vehicle width direction of the left front surface portion <NUM>, a left upper surface portion <NUM> that spreads horizontally from the upper end portion of the left front surface portion <NUM> toward the vehicle rear side, a left lower surface portion <NUM> that spreads from the lower end portion of the left front surface portion <NUM> so as to face the left upper surface portion <NUM> in the up-down direction, and a left rear surface portion <NUM> that faces the left front surface portion <NUM> in the front-rear direction. The edges of the surface portions <NUM> to <NUM> of the left battery unit <NUM> are integrated with each other. The inner end portion in the vehicle width direction of the left front surface portion <NUM> is located behind the outer end portion in the vehicle width direction. This forms a space in which the transmission support member <NUM> is disposed while the left battery unit <NUM> is made as large as possible.

As illustrated in <FIG> and <FIG>, the left battery unit <NUM> has a first left case <NUM> and a second left case <NUM> divided in the up-down direction. The first left case <NUM> includes the left upper surface portion <NUM> and is located relatively upward. The second left case <NUM> includes the left lower surface portion <NUM> and is located relatively downward. The first left case <NUM> has a flange 41aL that extends along the edge in the lower end portion thereof and the second left case <NUM> has a flange 42aL that extends along the edge in the upper end portion thereof. The first left case <NUM> and the second left case <NUM> are connected to each other by a bolt with the flanges thereof abutting against each other in the up-down direction. A sealing member is disposed in the contact portion between the first left case <NUM> and the second left case <NUM>. The flanges 41aL and 42aL correspond to projecting portions that project toward the inner side in the vehicle width direction from the left inner side surface portion <NUM>.

The left battery unit <NUM> is supported by the vehicle body via a plurality of brackets. Specifically, a first left bracket <NUM> and a second left bracket <NUM> are mounted to the left outer side surface portion <NUM> of the left battery unit <NUM>. In addition, a third left bracket <NUM> is mounted to the left inner side surface portion <NUM> of the left battery unit <NUM>.

The first left bracket <NUM> is mounted at the middle position in the front-rear direction of the left outer side surface portion <NUM> and the second left bracket <NUM> is mounted at the position of the rear end of the left outer side surface portion <NUM>. As illustrated in <FIG>, the lower portion of the first left bracket <NUM> is mounted to the second left case <NUM> by bolts. Although not illustrated, the lower portion of the second left bracket <NUM> is mounted to the second left case <NUM> by bolts. The upper end portions of the first left bracket <NUM> and the second left bracket <NUM> are fixed to the lower surface of the left floor frame <NUM> by bolts (<FIG> illustrates only the connection portion between the first left bracket <NUM> and the left floor frame <NUM>).

The third left bracket <NUM> is mounted at the middle position in the front-rear direction on the left inner side surface portion <NUM>. As illustrated in <FIG>, the lower portion of the third left bracket <NUM> is mounted to the flange 41aL of the first left case <NUM> and the flange 42aL of the second left case <NUM> from the upper side by bolts. The upper end portion of the third left bracket <NUM> is fixed to the upper tunnel reinforcement <NUM> by bolts. <FIG> illustrates the connection portion between a third right bracket 53R, which will be described later, and the upper tunnel reinforcement <NUM>, and the connection portion between a third left bracket <NUM> and the upper tunnel reinforcement <NUM> cannot be seen because the upper tunnel reinforcement <NUM> overlaps the connection portion.

As illustrated in <FIG>, a left inner protector <NUM> that covers the left inner side surface portion <NUM> from the inner side in the vehicle width direction is mounted to the front portion of the left inner side surface portion <NUM>. The left inner protector <NUM> is a member that prevents the transfer 4a from coming into contact with the left inner side surface portion <NUM> of the left battery unit <NUM> when the transmission <NUM> enters the floor tunnel <NUM> together with the transfer 4a at the time of a front collision. In addition, the left inner protector <NUM> is a member that prevents the left battery unit <NUM> from being removed from the vehicle body by a collision load applied downward to the left battery unit <NUM> when the transfer 4a is caught by the flange of the first left case <NUM>. The left inner protector <NUM> is made of, for example, cast iron.

The left inner protector <NUM> includes a left protection portion <NUM> that actually covers the left inner side surface portion <NUM> and a left vehicle body connection portion <NUM> that is connected to the vehicle body structural member. The left vehicle body connection portion <NUM> is provided in the upper end portion of the left protection portion <NUM>.

The left protection portion <NUM> covers the portion of the left inner side surface portion <NUM> of the first left case <NUM>. As illustrated in <FIG>, the width in the front-rear direction of the left protection portion <NUM> is gradually smaller toward the upper side. Specifically, the front end portion of the left protection portion <NUM> is inclined to the rear side toward the left vehicle body connection portion <NUM>, and the rear end portion of the left protection portion <NUM> extends straight toward the upper side, curves toward the front side, and extends toward the left vehicle body connection portion <NUM> while being inclined. Accordingly, the left vehicle body connection portion <NUM> has a smaller width in the vehicle front-rear direction than the left protection portion <NUM>.

As illustrated in <FIG> and <FIG>, the inner surface (that is, the right surface) in the vehicle width direction of the left protection portion <NUM> is located at substantially the same position in the vehicle width direction as the inner ends in the vehicle width direction of the upper and lower flanges 41aL and 42aL.

As illustrated in <FIG> and <FIG>, the outer surface (that is, the left surface) in the vehicle width direction of the left protection portion <NUM> is provided with two left mount portions <NUM> through which the left inner protector <NUM> is mounted to the left battery unit <NUM>. The left mount portions <NUM> are provided in the end portion on the front side and the lower side and the end portion on the rear side and the lower side of the left protection portion <NUM>, respectively. Bolts <NUM> (shaft-like fastening members) are inserted into the left mount portions <NUM> so as to extend in the up-down direction. As illustrated in <FIG>, the bolts <NUM> are fastened to the upper and lower flanges 41aL and 42aL, respectively, so as to extend in the up-down direction (<FIG> illustrates only the left mount portion <NUM> on the rear side). This fixes the left inner protector <NUM> to the upper and lower flanges 41aL and 42aL of the left battery unit <NUM>.

A plurality of reinforcing ribs are provided on the outer surface (that is, the left surface) in the vehicle width direction of the left protection portion <NUM>. The reinforcing ribs include a plurality of (five in this case) left vertical ribs <NUM> that extend in the up-down direction and one left horizontal rib <NUM> that extends in the front-rear direction. The left vertical ribs <NUM> are wider toward the left horizontal rib <NUM>. The left vertical rib <NUM> on the frontmost side of the plurality of left vertical ribs <NUM> is integrated with the left mount portion <NUM> on the front side. The left vertical rib <NUM> on the rearmost side of the plurality of left vertical ribs <NUM> is integrated with the left mount portion <NUM> on the rear side.

The left horizontal rib <NUM> extends straight from the position of the left vertical rib <NUM> located on the rearmost side to the front side through the middle portion in the up-down direction of the left vertical rib <NUM>, and then is integrated with the upper end portion of the left vertical rib <NUM> located on the frontmost side along the front end portion of the left protection portion <NUM>. The left horizontal rib <NUM> is integrated with the left vertical ribs <NUM>. As illustrated in <FIG>, the left horizontal rib <NUM> is located at the same height as the tunnel panel <NUM>. The left horizontal rib <NUM> projects to the outer side in the vehicle width direction of the left vertical ribs <NUM> and the tip thereof is located near the tunnel panel <NUM>.

As illustrated in <FIG> and <FIG>, the left vehicle body connection portion <NUM> extends toward the upper side from the upper end portion of the left protection portion <NUM> and is bent substantially at a right angle toward the inner side in the vehicle width direction. The left vehicle body connection portion <NUM> is fixed to the upper tunnel reinforcement <NUM> by a bolt <NUM>. As illustrated in <FIG>, the bolt <NUM> is fastened to the weld nut provided in the upper tunnel reinforcement <NUM> so as to extend in the up-down direction.

The left mount portions <NUM> are mounted to the left battery unit <NUM> and the left vehicle body connection portion <NUM> is connected to the upper tunnel reinforcement <NUM>, whereby the left battery unit <NUM> is supported by the vehicle body via the left inner protector <NUM>. That is, the left inner protector <NUM> also serves as a bracket. It should be noted that <FIG> illustrates the connection portion between a right inner protector 70R, which will be described later, and the upper tunnel reinforcement <NUM> and the connection portion between the left inner protector <NUM> and the upper tunnel reinforcement <NUM> cannot be seen because the upper tunnel reinforcement <NUM> overlaps the connection portion.

As illustrated in <FIG>, the left front surface portion <NUM> of the left battery unit <NUM> is provided with a left front protector <NUM> that covers the inner portion in the vehicle width direction of the left front surface portion <NUM> from the front side. The left front protector <NUM> is provided to suppress a direct collision between the left battery unit <NUM> and the transmission support member <NUM> when the transmission support member <NUM> moves backward at the time of a front collision.

The inner end portion in the vehicle width direction of the left front protector <NUM> is located on the inner side in the vehicle width direction of the front end portion of the left inner protector <NUM>. Accordingly, a part of the front end portion of the left inner protector <NUM> is covered with the inner end portion in the vehicle width direction of the left front protector <NUM> as seen from the front side. In addition, the inner end portion in the vehicle width direction of the left front protector <NUM> is inclined to the rear side toward the inner side in the vehicle width direction. That is, the left front protector <NUM> covers the front end portion of the left inner protector <NUM> even in the vehicle width direction.

The left front protector <NUM> is mounted to the left battery unit <NUM> via left front mount portions <NUM> and <NUM> at two positions.

Next, the peripheral structure of the right battery unit 40R will be described. In the peripheral structure of the right battery unit 40R, the detailed shape is different from that of the left battery unit <NUM>, but the basic structure is symmetrical with respect to that of the left battery unit <NUM>. Accordingly, only the different portion between the peripheral structure of the right battery unit 40R and the peripheral structure of the left battery unit <NUM> will be described in detail and the same portion as the peripheral structure of the left battery unit <NUM> will not be described in detail as appropriate.

As illustrated in <FIG> and <FIG>, the right battery unit 40R has a box shape and is substantially rectangular in bottom view. The right battery unit 40R includes the right front surface portion 43R, a right outer side surface portion 44R that extends in the front-rear direction from the outer end portion in the vehicle width direction of the right front surface portion 43R, a right inner side surface portion 45R that extends in the front-rear direction from the inner end portion in the vehicle width direction of the right front surface portion 43R, a right upper surface portion 46R that spreads horizontally from the upper end portion of the right front surface portion 43R toward the vehicle rear side, a right lower surface portion 47R that spreads from the lower end portion of the right front surface portion 43R so as to face the right upper surface portion 46R in the up-down direction, and a right rear surface portion 48R that faces the right front surface portion 43R in the front-rear direction. The edges of the surface portions 43R to 48R of the right battery unit 40R are integrated with each other. In the right front surface portion 43R, the inner portion in the vehicle width direction is located behind the outer portion in the vehicle width direction.

As illustrated in <FIG>, <FIG>, and <FIG>, the right battery unit 40R includes a first right case 41R and a second right case 42R divided in the up-down direction. The first right case 41R has a flange 41aR that extends along the edge in the lower end portion and the second right case 42R has a flange 42aR that extends along the edge in the upper end portion. The first right case 41R and the second right case 42R are connected to each other by bolts with the flanges thereof abutting against each other in the up-down direction. A sealing member is disposed in the contact portion between the first right case 41R and the second right case 42R. The flanges 41aR and 42aR correspond to projecting portions that project toward the inner side in the vehicle width direction from the right inner side surface portion 45R.

The right battery unit 40R is supported by the vehicle body via a plurality of brackets. Specifically, a first right bracket 51R and a second right bracket 52R are mounted to the right outer side surface portion 44R of the right battery unit 40R. In addition, a third right bracket 53R is mounted to the right inner side surface portion 45R of the right battery unit 40R. Since the structures of the first to third right brackets 51R to 53R are symmetrical with respect to those of the first to third left brackets <NUM> to <NUM>, detailed description thereof will be omitted.

As illustrated in <FIG> and <FIG>, the right inner protector 70R that covers the right inner side surface portion 45R from the inner side in the vehicle width direction is mounted to the front portion of the right inner side surface portion 45R. Since the operation of the right inner protector 70R on the right battery unit 40R is the same as the operation of the left inner protector <NUM> on the left battery unit <NUM>, detailed description thereof will be omitted. The right inner protector 70R is made of, for example, cast iron.

The right inner protector 70R includes a right protection portion 71R that actually covers the right inner side surface portion 45R and a right vehicle body connection portion 72R that is connected to the vehicle body structural member. The right vehicle body connection portion 72R is provided in the upper end portion of the right protection portion 71R.

The right protection portion 71R covers the portion of the first right case 41R of the right inner side surface portion 45R. As illustrated in <FIG>, the right protection portion 71R is symmetrical in the front-rear direction, extends straight from the lower side to the upper side, and then gradually reduces in width in the front-rear direction toward the right vehicle body connection portion 72R. The right vehicle body connection portion 72R has a smaller width in the vehicle front-rear direction than the right protection portion 71R.

As illustrated in <FIG> and <FIG>, the inner surface (that is, the left surface) in the vehicle width direction of the right protection portion 71R is located at substantially the same position as the inner end in the vehicle width direction of the upper and lower flanges 41aR and 42aR.

As illustrated in <FIG>, <FIG>, and <FIG>, two right mount portions 73R through which the right inner protector 70R is mounted to the right battery unit 40R are provided on the outer surface (that is, the right surface) in the vehicle width direction of the right protection portion 71R. One of the right mount portions 73R is provided in the end portion on the front side and the lower side of the right protection portion 71R and the other of the right mount portions 73R is provided in the end portion on the rear side and the lower side, respectively. Bolts <NUM> (shaft-like fastening members) are inserted into the right mount portions 73R so as to extend in the up-down direction. As illustrated in <FIG>, the bolts <NUM> are fastened to the upper and lower flanges 41aR and 42aR, respectively, while extending in the up-down direction (<FIG> illustrates only the right mount portion 73R on the rear side). This fixes the right inner protector 70R to the upper and lower flanges 41aR and 42aR of the right battery unit 40R.

As illustrated in <FIG>, a plurality of reinforcing ribs are provided on the outer surface (that is, the left surface) in the vehicle width direction of the right protection portion 71R. The reinforcing ribs include a plurality of (five in this case) right vertical ribs 74R that extend in the up-down direction and one right horizontal rib 75R that extends in the front-rear direction. The right vertical ribs 74R are wider toward the right horizontal rib 75R. The right vertical rib 74R on the frontmost side of the plurality of right vertical ribs 74R is integrated with the right mount portion 73R on the front side. The right vertical rib 74R on the rearmost side of the plurality of right vertical ribs 74R is integrated with the right mount portion 73R on the rear side.

The right horizontal rib 75R extends straight from the upper end position of the right vertical rib 74R located on the rearmost side to the front side through the middle portion in the up-down direction of the right vertical rib 74R, and then is integrated with the upper end portion of the right vertical rib 74R located on the frontmost side. The right horizontal rib 75R is integrated with the right vertical ribs 74R. As illustrated in <FIG>, the right horizontal rib 75R is located at the same height as the tunnel panel <NUM>. The right horizontal rib 75R projects to the outer side in the vehicle width direction of the right vertical rib 74R and the tip thereof is located near the tunnel panel <NUM>.

As illustrated in <FIG>, the right vehicle body connection portion 72R extends toward the upper side from the upper end portion of the right protection portion 71R and is bent substantially at a right angle toward the inner side in the vehicle width direction. The right vehicle body connection portion 72R is fixed to the upper tunnel reinforcement <NUM> by a bolt <NUM>. As illustrated in <FIG>, the bolt <NUM> is fastened to the weld nut provided in the upper tunnel reinforcement <NUM> so as to extend in the up-down direction.

The right mount portions 73R are mounted to the right battery unit 40R and the right vehicle body connection portion 72R is connected to the upper tunnel reinforcement <NUM>, whereby the right battery unit 40R is supported by the vehicle body via the right inner protector 70R. That is, the right inner protector 70R also serves as a bracket.

As illustrated in <FIG>, <FIG>, and <FIG>, the right front surface portion 43R of the right battery unit 40R is provided with a right front protector 60R that covers the inner portion in the vehicle width direction of the right front surface portion 43R from the front side. The right front protector 60R is provided to suppress a direct collision between the right battery unit 40R and the transmission support member <NUM> when the transmission support member <NUM> moves backward at the time of a front collision.

The inner end portion in the vehicle width direction of the right front protector 60R is located on the inner side in the vehicle width direction of the front end portion of the right inner protector 70R. Accordingly, a part of the front end portion of the right inner protector 70R is covered with the inner end portion in the vehicle width direction of the right front protector 60R as seen from the front side. In addition, the inner end portion in the vehicle width direction of the right front protector 60R is inclined to the rear side toward the inner side in the vehicle width direction. That is, the right front protector 60R covers the front end portion of the right inner protector 70R even in the vehicle width direction.

The right front protector 60R is mounted to the right battery unit 40R via right front mount portions 61R and 62R at two positions.

Here, when the transfer 4a of the transmission <NUM> is disposed in the floor tunnel <NUM> as in the embodiment, the transfer 4a moves backward while entering the floor tunnel <NUM> at the time of a front collision. In addition, since the rear propeller shaft <NUM> is provided with the universal joint 9a, the rear propeller shaft <NUM> may pivot in the left-right direction (vehicle width direction) at the time of a front collision. When the rear propeller shaft <NUM> pivots in the left-right direction, the transfer 4a moves backward, diagonally to the left or diagonally to the right. Accordingly, the transfer 4a may come into contact with the left battery unit <NUM> or the right battery unit 40R. In particular, since the transfer 4a is disposed in proximity to the portions on the front side and the upper side of the left and right battery units <NUM> and 40R and is inclined to the lower side toward the rear side, the transfer 4a may move backward while rubbing the left or right inner surface portion <NUM> or 45R diagonally downward at the time of a front collision.

In contrast, since the left and right inner protectors <NUM> and 70R are provided on the left and right inner surfaces <NUM> and 45R in the embodiment, it is possible to prevent the transfer 4a from coming into contact with the left and right inner surfaces <NUM> and 45R at the time of a front collision. This can suppress damage to the left and right battery units <NUM> and 40R at the time of a front collision.

In addition, since the left and right inner side surface portions <NUM> and 45R are provided with the flanges 41aL, 42aL, 41aR, and 42aR that project toward the inner side in the vehicle width direction in the embodiment, the left or right inner side surface portion <NUM> or 45R may drop because the transfer 4a is caught by the flanges 41aL, 42aL, 41aR, and 42aR at the time of a front collision. However, since the inner surfaces in the vehicle width direction of the protection portions <NUM> and 71R of the left and right inner protectors <NUM> and 70R are present at substantially the same positions in the vehicle width direction as the inner edges in the vehicle width direction of the flanges 41aL, 42aL, 41aR, and 42aR in the embodiment, it is possible to effectively prevent the transfer 4a from being caught by the flanges 41aL, 42aL, 41aR, and 42aR.

In addition, in the embodiment, the left and right inner protectors <NUM> and 70R include reinforcing ribs including the plurality of left and right vertical ribs <NUM> and 74R that extend in the up-down direction and left and right horizontal ribs <NUM> and 75R that extend in the front-rear direction. This can suppress damage to the left and right inner protectors <NUM> and 70R even when a collision load is input from the transfer 4a to the left and right inner protectors <NUM> and 70R at the time of a front collision. As a result, damage to the left and right battery units <NUM> and 40R can be suppressed more effectively.

In addition, in the embodiment, the left and right horizontal ribs <NUM> and 75R are located at the same height as the tunnel panel <NUM>. That is, when the transfer 4a moves diagonally backward and comes into contact with the left or right inner protector <NUM> or 70R, a collision load in the vehicle width direction (left-right direction) is input to the inner protector with which the transfer 4a comes into contact. When the inner protector is deformed by this collision load, the left or right horizontal rib <NUM> or 75R comes into contact with the tunnel panel <NUM>, whereby the collision load can be received by the vehicle body. This suppresses the deformation of the left and right battery units <NUM> and 40R. Accordingly, damage to the left and right battery units <NUM> and 40R can be suppressed more effectively.

In addition, in the embodiment, the left inner protector <NUM> is fixed to the upper and lower flanges 41aL and 42aL of the left inner side surface portion <NUM> by the bolts <NUM>, the right inner protector 70R is fixed to the upper and lower flanges 41aR and 42aR of the right inner side surface portion 45R by the bolts <NUM>, and the bolts <NUM> and <NUM> are fastened so as to extend in the up-down direction. Accordingly, even when the transfer 4a comes into contact with the left or right inner protector <NUM> or 70R at the time of a front collision and the collision load is input to the left or right inner protector <NUM> or 70R, the collision load can be received by the bolts <NUM> or the bolts <NUM>. As a result, the left and right inner protectors <NUM> and 70R can be prevented from peeling off from the left and right inner side surface portions <NUM> and 45R at the time of a front collision. Accordingly, damage to the left and right battery units <NUM> and 40R can be suppressed more effectively.

In addition, in the embodiment, the left and right front protectors <NUM> and 60R that cover the front end portions of the left and right inner protectors <NUM> and 70R from the vehicle front side are mounted to the left and right battery units <NUM> and 40R, respectively. This can prevent the left or right inner protector <NUM> or 70R from peeling off from the left or right battery units <NUM> or 40R because the transfer 4a is caught by the front end portion of the left or right inner protector <NUM> or 70R at the time of a front collision. As a result, damage to the left and right battery units <NUM> and 40R can be suppressed more effectively.

In addition, in the embodiment, the left and right inner protectors <NUM> and 70R are connected to the vehicle body structural member (upper tunnel reinforcement <NUM>) via the left and right vehicle body connection portions <NUM> and 72R. This can cause the vehicle body to receive the collision load input when the transfer 4a comes into contact with the left and right inner protectors <NUM> and 70R. As a result, damage to the left and right battery units <NUM> and 40R can be suppressed.

In addition, in the embodiment, the left and right vehicle body connection portions <NUM> and 72R have smaller widths in the front-rear direction than the left and right protection portions <NUM> and 71R. This can reduce the weight of the vehicle <NUM> while suppressing damage to the left and right battery units <NUM> and 40R.

The invention as disclosed herein is not limited to the embodiment described above.

For example, the vehicle <NUM> is a four-wheel-drive vehicle in the embodiment described above. However, the vehicle <NUM> is not limited to a four-wheel-drive vehicle and may be, for example, an FR vehicle. When the vehicle <NUM> is a FR vehicle, the transfer 4a and the front propeller shaft <NUM> are omitted. In addition, the vehicle <NUM> may be an electric vehicle that does not have the engine <NUM> but has only the motor <NUM> as the drive source.

In addition, in the embodiment described above, the left and right inner protectors <NUM> and 70R have the left and right vehicle body connection portions <NUM> and 72R and also serve as brackets. The left and right inner protectors <NUM> and 70R are not limited to this example and do not need to have the left and right vehicle body connection portions <NUM> and 72R.

The embodiment described above is only an example.

Claim 1:
A lower structure of a vehicle (<NUM>) in which a rear wheel (<NUM>) serves as a drive wheel, the lower structure comprising:
a gearbox (<NUM>) disposed with at least a portion thereof present in a floor tunnel (<NUM>) formed by a tunnel panel (<NUM>), the portion being present on a vehicle rear side;
a propeller shaft (<NUM>) that extends from the gearbox (<NUM>) toward the vehicle rear side, the propeller shaft (<NUM>) transmitting power from the gearbox (<NUM>) to the rear wheel (<NUM>) ; and
left and right battery units (<NUM>, 40R) disposed on a vehicle lower side of left and right floor panels (<NUM>), the left and right floor panels (<NUM>) being disposed on a vehicle left side and a vehicle right side of the floor tunnel (<NUM>),
wherein the portion of the gearbox (<NUM>) on the vehicle rear side is disposed in proximity to portions on a vehicle front side and a vehicle upper side of the left and right battery units (<NUM>, 40R),
each of the left and right battery units (<NUM>, 40R) has an inner side surface portion (<NUM>, 45R) that extends in a vehicle front-rear direction along each of both side end portions in a vehicle width direction of the floor tunnel (<NUM>), and
each of the left and right battery units (<NUM>, 40R) has an inner protector (<NUM>, 70R) which is mounted to the battery unit (<NUM>, 40R) and covers a front end portion of the inner side surface portion (<NUM>, 45R) from an inner side in the vehicle width direction.