Patent Description:
<CIT> discloses an electric vehicle equipped with a battery as a drive source.

In <CIT>, there is provided a battery case formed by a center frame and side frames extending in a vehicle front-rear direction, a front frame disposed on a vehicle front side, a rear frame disposed on a vehicle rear side, and cross members performing partition in a vehicle width direction. The battery is disposed in a placement portion formed by arranging the frames and the members in a grid pattern. Further, the battery case is provided with a side sill outside the side frame in a width direction of a vehicle body. <CIT> discloses a vehicle battery pack frame.

Since the electric vehicle described in <CIT> has the above-described configuration, for example, even when a load is input from a side surface of the vehicle, the load does not directly act on the battery. On the other hand, a further improvement in durability against the load input to the side surface of the electric vehicle is desired.

An object of the present invention is to provide a technique for improving durability against a load input to a side surface of an electric vehicle.

According to one aspect of the present invention, a battery case that accommodates a battery for an electric vehicle is provided.

The battery case includes a pair of side frames, a cross member, and a side bracket. The pair of side frames constitute left and right side walls of the battery case in a vehicle width direction and extend along a vehicle front-rear direction. The cross member partitions an internal space of the battery case in the vehicle front-rear direction and extends from one of the side frames to the other side frame. The side bracket is fixed to an outer surface of the side frame and is configured to attach the battery case to a vehicle body. The side frame includes a frame rib extending in the vehicle width direction inside the side frame and the side bracket includes a bracket rib extending in the vehicle width direction inside the side bracket.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

<FIG> is a side perspective view showing a main part of an electric vehicle <NUM> on which a battery case <NUM> according to an embodiment of the present invention is mounted. <FIG> is a perspective plan view of the main part of the electric vehicle <NUM> viewed from a bottom side.

As shown in <FIG>, the battery case <NUM> accommodates a battery used as a drive source of the electric vehicle <NUM> (hereinafter, referred to as a vehicle <NUM>). The battery case <NUM> is disposed below a floor of the vehicle <NUM> over a region corresponding to the floor of the vehicle <NUM>.

<FIG> is a perspective view illustrating the battery case <NUM>. In <FIG>, arrows representing a vehicle front direction F and a vehicle rear direction R, an arrow representing a vehicle width direction W, and an arrow representing a vehicle upper-lower direction Z are described. The vehicle front-rear direction, the vehicle width direction, and the vehicle upper-lower direction may be referred to as a front-rear direction FR, a width direction W, and an upper-lower direction Z, respectively.

As shown in <FIG>, the battery case <NUM> includes side frames <NUM>, cross members <NUM>, a front frame <NUM>, a rear frame <NUM>, and a bottom plate <NUM>.

A pair of side frames <NUM> are provided at a predetermined interval in the vehicle width direction W, and constitute left and right side walls of the battery case <NUM>. Further, the side frame <NUM> extends along the front-rear direction FR of the vehicle <NUM>.

The front frame <NUM> constitutes a front side wall in the vehicle front-rear direction FR, and the rear frame <NUM> constitutes a rear side wall in the vehicle front-rear direction FR. Further, the bottom plate <NUM> constitutes a case bottom surface that functions as a battery placement surface in the battery case <NUM>.

The side frames <NUM>, the front frame <NUM>, and the rear frame <NUM> are provided upright with respect to a peripheral edge of the bottom plate <NUM>, and are joined by welding, thereby constituting a box-shaped case. Further, an internal space formed by the side frames <NUM>, the front frame <NUM>, and the rear frame <NUM> is partitioned by a plurality of cross members <NUM>.

Each of the cross members <NUM> partitions the internal space of the battery case <NUM> in the front-rear direction FR, and extends from one side frame <NUM> to the other side frame <NUM>. In the first embodiment, the battery case <NUM> includes four cross members <NUM>.

Although not shown in <FIG>, the battery is accommodated in each of a plurality of sections formed by the cross members <NUM> in the internal space of the battery case <NUM>. A plurality of battery modules constitute one battery (battery pack). The battery case <NUM> is covered with a case cover (not shown) in a state in which the battery module formed by a lithium ion battery or the like is accommodated in the internal space.

As described above, the battery case <NUM> in which the battery is accommodated includes side brackets <NUM> and rear side brackets 60R on an outer side in a vehicle body width direction of the side frame <NUM>, and is attached to a vehicle body of the vehicle <NUM> by the side brackets <NUM> and the rear side brackets 60R.

From the viewpoint of increasing a load of the battery as the drive source, as shown in <FIG>, the battery case <NUM> is formed by maximally using a floor region of the vehicle <NUM>. Therefore, in the width direction W of the vehicle <NUM>, a space between the battery case <NUM> and the vehicle body of the vehicle <NUM> is reduced. Therefore, the battery case <NUM> is required to have sufficient durability against a load input to the vehicle <NUM> particularly due to a collision or the like from a side among an impact that may be input to the vehicle <NUM>.

<FIG> is a cross-sectional view taken along a line IV-IV in <FIG>. As shown in <FIG>, the side bracket <NUM> is fixed to an outer surface <NUM> of each of the side frames <NUM> that form the left and right walls of the internal space of the battery case <NUM> by welding or the like.

The side frame <NUM> is a hollow plate-shaped member and includes a frame rib <NUM> extending in the width direction W inside the side frame <NUM>. In the present embodiment, the side frame <NUM> includes four frame ribs, that is, frame ribs <NUM>, <NUM>, <NUM>, and <NUM> that partition an inside of the side frame <NUM> in the upper-lower direction Z.

Strength of the side frame <NUM> in the width direction W is increased by the frame ribs <NUM>, <NUM>, <NUM>, and <NUM> extending in the width direction W inside the side frame <NUM>.

Next, the side bracket <NUM> fixed to an outside of the side frame <NUM> will be described. The side bracket <NUM> includes a main body portion <NUM> that attaches the battery case <NUM> to the vehicle body, an abutting portion <NUM> that constitutes one surface of the main body portion <NUM> on a side frame <NUM> side and abuts against the outer surface <NUM> of the side frame <NUM>, and a support portion <NUM> that protrudes from a lower end 62d of the abutting portion <NUM> and supports the battery case <NUM> from below. The abutting portion <NUM> is fixed to the outer surface <NUM> and the support portion <NUM> is fixed to the bottom plate <NUM> of the battery case <NUM> by welding or the like.

The main body portion <NUM> includes a protruding end portion <NUM> that protrudes from the abutting portion <NUM> toward an outside of the vehicle in the width direction W of the battery case <NUM>. A hole <NUM> that penetrates in the upper-lower direction Z is formed in the protruding end portion <NUM>, and the side bracket <NUM> and the vehicle <NUM> are fixed by a bolt that pass through the hole <NUM>.

The side bracket <NUM> is a hollow rod-shaped member, and includes a bracket rib <NUM> extending in the width direction W inside the side bracket <NUM>. In this way, strength of the side bracket <NUM> in the width direction W is increased by the bracket rib <NUM> extending in the width direction W inside the side bracket <NUM>.

The rear side bracket 60R will be described in conjunction with a second embodiment of the side bracket <NUM>.

Next, the cross member <NUM> disposed between the pair of side frames <NUM> will be described. The cross member <NUM> is a hollow plate-shaped member and includes a member rib <NUM> extending in the width direction W inside the cross member <NUM>. In the present embodiment, the cross member <NUM> includes four member ribs, that is, member ribs <NUM>, <NUM>, <NUM>, and <NUM> that partition an interior of the cross member <NUM> in the upper-lower direction Z. Thus, strength of the cross member <NUM> in the width direction W is increased by the member ribs <NUM>, <NUM>, <NUM>, and <NUM> extending in the width direction W inside the cross member <NUM>.

In the present embodiment, as shown in <FIG>, an end portion 65e of the bracket rib <NUM> on the side frame <NUM> side and an end portion 14b of the frame rib <NUM> on a side bracket <NUM> side are disposed in a manner of corresponding to each other in the upper-lower direction Z. That is, a height position in the upper-lower direction Z of the end portion 65e of the bracket rib <NUM> on the side frame <NUM> side is substantially the same as a height position in the upper-lower direction Z of the end portion 14b of the frame rib <NUM> on the side bracket <NUM> side.

Accordingly, the strength of the side frame <NUM> and the side bracket <NUM> in the width direction W is increased, and a load transmission path (hereinafter, referred to as a load path) for transmitting, from the bracket rib <NUM> to the frame rib <NUM>, the load input to the side bracket <NUM> from the side of the vehicle <NUM>, is formed.

As shown in <FIG>, an end portion 11a of the frame rib <NUM> on a cross member <NUM> side and an end portion 21e of the member rib <NUM> on the side frame <NUM> side are disposed in a manner of corresponding to each other in the vehicle upper-lower direction Z. That is, a height position in the upper-lower direction Z of the end portion 11a of the frame rib <NUM> on the cross member <NUM> side is substantially the same as a height position in the upper-lower direction Z of the end portion 21e of the member rib <NUM> on the side frame <NUM> side.

Further, an end portion 12a of the frame rib <NUM> on the cross member <NUM> side and an end portion 22e of the member rib <NUM> on the side frame <NUM> side are disposed in a manner of corresponding to each other in the vehicle upper-lower direction Z. That is, a height position in the upper-lower direction Z of the end portion 12a of the frame rib <NUM> on the cross member <NUM> side is substantially the same as a height position in the upper-lower direction Z of the end portion 22e of the member rib <NUM> on the side frame <NUM> side.

Similarly, height positions in the upper-lower direction Z of an end portion 13a of the frame rib <NUM> and an end portion 14a of the frame rib <NUM> on the cross member <NUM> side are substantially the same as height positions in the upper-lower direction Z of an end portion 23e of the member rib <NUM> and an end portion 24e of the member rib <NUM> on the side frame <NUM> side, respectively.

Therefore, load paths for transmitting a load input to the frame ribs <NUM>, <NUM>, <NUM>, and <NUM> of the side frame <NUM> to the member ribs <NUM>, <NUM>, <NUM>, and <NUM> of the cross member <NUM> are formed.

As shown in <FIG>, the side bracket <NUM> includes a main body upper surface portion <NUM> extending from the protruding end portion <NUM> to an upper end 62u of the abutting portion <NUM>, and a main body lower surface portion <NUM> extending from the protruding end portion <NUM> to a lower end 62d of the abutting portion <NUM>. A cross-sectional shape in the upper-lower direction Z along the width direction W is a shape that spreads in the upper-lower direction Z from the protruding end portion <NUM> toward a vehicle inner side in the width direction W and is continuous with the abutting portion <NUM>.

Further, the side bracket <NUM> is disposed such that the upper end 62u of the abutting portion <NUM> and an end portion 13b of the frame rib <NUM> on the side bracket <NUM> side correspond to each other in the upper-lower direction Z. That is, a height position of the upper end 62u of the abutting portion <NUM> in the upper-lower direction Z and a height position of the frame rib <NUM> in the upper-lower direction Z are substantially the same.

Accordingly, a load path is formed in which a load input from the protruding end portion <NUM> of the side bracket <NUM> is dispersed so as to spread in the upper-lower direction Z and transmitted to the side frame <NUM>.

The side bracket <NUM> has a passage <NUM> extending in the front-rear direction FR by partitioning an inside of the side bracket <NUM> by the bracket rib <NUM>. In the present embodiment, the passage <NUM> is a refrigerant passage through which a refrigerant that cools an in-vehicle device such as a motor for a rear wheel provided in the vehicle <NUM> passes.

As shown in <FIG>, a part of each of the pair of side frames <NUM> is curved such that a distance between the side frames <NUM> in the width direction W is gradually decreases along the front-rear direction FR so that the battery case <NUM> has a shape corresponding to a place where the battery case <NUM> can be mounted in the vehicle <NUM>. A curved portion 10C is seamless, that is, formed seamlessly, by bending in a plurality of stages.

The battery case <NUM> according to the first embodiment includes the pair of side frames <NUM> constituting the left and right side walls in the vehicle width direction W, the cross members <NUM> each extending from one side frame <NUM> to the other side frame <NUM>, and the side brackets <NUM> each fixed to the outer surface <NUM> of the side frame <NUM> and attaching the battery case <NUM> to the vehicle body. In the battery case <NUM>, the pair of side frames <NUM> constituting the left and right side walls in the vehicle width direction W are supported by the cross members <NUM> in the vehicle width direction W. The side frame <NUM> includes the frame ribs <NUM>, <NUM>, <NUM>, and <NUM> extending in the vehicle width direction W in the side frame <NUM>. The side frame <NUM> is supported in the vehicle width direction W by frame ribs <NUM>, <NUM>, <NUM>, and <NUM> inside the side frame <NUM>. The side bracket <NUM> includes the bracket rib <NUM> extending in the vehicle width direction W inside the side bracket <NUM>. The side bracket <NUM> is supported by the bracket rib <NUM> in the vehicle width direction W inside the side bracket <NUM>.

Thus, the strength of the side frame <NUM> and the side bracket <NUM> in the vehicle width direction W is increased by the frame ribs <NUM>, <NUM>, <NUM>, and <NUM> and the bracket rib <NUM>, and the pair of side frames <NUM> are supported by the cross members <NUM> in the vehicle width direction W. Therefore, since the strength of the battery case <NUM> is increased when the load is applied in the vehicle width direction W, the durability against, for example, a collision from a side surface of the vehicle <NUM> can be improved.

The battery case <NUM> is disposed such that the end portion 65e of the bracket rib <NUM> on the side frame <NUM> side and the end portion 14b of the frame rib <NUM> on the side bracket <NUM> side correspond to each other in the vehicle upper-lower direction Z. Accordingly, the load path is formed from the bracket rib <NUM> to the frame rib <NUM>. Therefore, the load input to the side bracket <NUM> from an outer side in the vehicle width direction W can be more reliably dispersed from the side bracket <NUM> to the side frame <NUM>.

Further, in the side frame <NUM> and the side bracket <NUM>, a height position of the frame rib <NUM> in the vehicle upper-lower direction Z and a height position of the bracket rib <NUM> are aligned, so that rigidity of the battery case <NUM> in the vehicle width direction W is increased, and the load input from the side of the vehicle <NUM> can be smoothly transmitted in the vehicle width direction W of the battery case <NUM>.

In the battery case <NUM>, the cross member <NUM> includes the member ribs <NUM>, <NUM>, <NUM>, and <NUM> extending in the vehicle width direction W in the cross member <NUM>. Accordingly, since the cross member <NUM> is supported in the vehicle width direction W by the member ribs <NUM>, <NUM>, <NUM>, <NUM> inside the cross member <NUM>, the strength of the cross member <NUM> in the vehicle width direction W can be improved.

In the battery case <NUM>, the height positions of the end portions 11a, 12a, 13a, and 14a of the frame ribs <NUM>, <NUM>, <NUM>, and <NUM> on the cross member <NUM> side in the vehicle upper-lower direction Z are aligned with the height positions of the end portions 21e, 22e, 23e, and 24e of the member ribs <NUM>, <NUM>, <NUM>, and <NUM> on the side frame <NUM> side, respectively.

Therefore, in the battery case <NUM>, the load paths are formed from the frame ribs <NUM>, <NUM>, <NUM>, and <NUM> to the member ribs <NUM>, <NUM>, <NUM>, and <NUM>. Accordingly, the load input to the side bracket <NUM> from the outer side in the vehicle width direction W can be more reliably dispersed from the side frame <NUM> to the cross member <NUM>.

Further, in the side frame <NUM> and the side bracket <NUM>, the height position of the frame rib <NUM> and the height position of the bracket rib <NUM> in the vehicle upper-lower direction Z are aligned, and the height positions of the end portions 11a, 12a, 13a, 14a of the frame ribs <NUM>, <NUM>, <NUM>, <NUM> on the cross member <NUM> side and the height positions of the end portions 21e, 22e, 23e, 24e of the member ribs <NUM>, <NUM>, <NUM>, <NUM> on the side frame <NUM> side are aligned, respectively, and thus the rigidity of the battery case <NUM> in the vehicle width direction W is increased, and the load input from the side of the vehicle <NUM> can be smoothly transmitted in the vehicle width direction W of the battery case <NUM>.

In the battery case <NUM>, the side bracket <NUM> includes the abutting portion <NUM> that abuts against the outer surface <NUM> of the side frame <NUM> and the support portion <NUM> that supports a bottom portion of the battery case <NUM> from below. That is, the battery case <NUM> is supported by the vehicle body in a manner of being embraced by the side bracket <NUM>. Therefore, even when an excessive load is input to the side surface of the vehicle <NUM>, it is possible to prevent joining between the side bracket <NUM> and the battery case <NUM> from being broken and the battery case <NUM> from falling off from the vehicle body.

In the battery case <NUM>, the upper end 62u of the abutting portion <NUM> and the end portion 13b of the frame rib <NUM> on the side bracket <NUM> side are disposed in a manner of corresponding to each other in the vehicle upper-lower direction Z. Therefore, the load path is formed from the abutting portion <NUM> of the side bracket <NUM> through the frame rib <NUM>. Accordingly, the load input from the side bracket <NUM> can be more reliably dispersed to the side frame <NUM>.

In the battery case <NUM>, the side bracket <NUM> has the passage <NUM> extending in the vehicle front-rear direction FR by partitioning the inside of the side bracket <NUM> by the bracket rib <NUM>. The passage <NUM> is a refrigerant passage for cooling the in-vehicle device. Therefore, it is not necessary to separately form the refrigerant passage, and a layout of the vehicle <NUM> can be improved. Since the refrigerant passage can be formed inside the side bracket <NUM>, the passage <NUM> as the refrigerant passage can be protected from the load from the outside.

In the battery case <NUM>, each of the pair of side frames <NUM> includes the curved portion 10C that is curved such that the distance between the pair of side frames <NUM> in the width direction W gradually decreases along the front-rear direction FR. The curved portion 10C is formed by seamless processing and includes no welded portion. Therefore, the rigidity of the side frame <NUM> can be increased compared to a case in which the side frame <NUM> is formed by a combination of linear members.

As described above, according to the battery case <NUM> described above, the durability against the load input to the side surface of the vehicle <NUM> can be improved, and the accommodated battery can be more reliably protected.

<FIG> is a cross-sectional view illustrating the battery case <NUM> according to a second embodiment of the present invention by cutting out the battery case <NUM> at the same position as the battery case <NUM> according to the first embodiment shown in <FIG>.

The battery case <NUM> shown as the second embodiment is different from the battery case <NUM> shown as the first embodiment in the structure of the side bracket <NUM>. In the battery case <NUM>, components having the same functions as those described in the battery case <NUM> are denoted by the same reference signs, and detailed description thereof will be omitted.

<FIG> is a perspective view of a main part of the battery case <NUM> in <FIG> as viewed from a bottom side of the vehicle <NUM>. As shown in <FIG>, a step portion <NUM> is formed on a lower surface of the bottom plate <NUM> constituting a bottom portion of the battery case <NUM> along the front-rear direction FR of the vehicle <NUM>.

A lower end surface of the support portion <NUM> is formed in a manner of protruding to one side, and the support portion <NUM> includes a facing portion <NUM> facing the step portion <NUM> located on a vehicle outer side in the width direction W.

In the battery case <NUM> according to the second embodiment, a flat structure is formed in which the step portion <NUM> and the facing portion <NUM> are disposed in a manner of butting each other, and the lower surface of the support portion <NUM> of the main body portion <NUM> and the lower surface of the bottom plate <NUM> forming the bottom portion of the battery case <NUM> are flat in the vehicle upper-lower direction Z.

Therefore, in the battery case <NUM>, when an excessive load is input, a load path is formed that connects the facing portion <NUM> of the side bracket <NUM> to the step portion <NUM> of the bottom plate <NUM>.

In the second embodiment, the side bracket <NUM> includes a first rib <NUM>, a second rib <NUM>, a third rib <NUM>, a fourth rib <NUM>, a fifth rib <NUM>, a sixth rib <NUM>, and a seventh rib <NUM> extending in the width direction W or the upper-lower direction Z inside the side bracket <NUM>.

One end of the first rib <NUM> is connected to the main body upper surface portion <NUM>, extends along the upper-lower direction Z, and the other end thereof is connected to the main body lower surface portion <NUM>. Further, the first rib <NUM> extends in the front-rear direction FR. One end of the second rib <NUM> is connected to the vicinity of a central portion 71c of the first rib <NUM> in the upper-lower direction Z and extends in the width direction W and the front-rear direction FR. One end of the third rib <NUM> is connected to an inner side in the width direction W with respect to a connection portion between the main body lower surface portion <NUM> and the first rib <NUM>, and extends in the width direction W and the front-rear direction FR. One end of the fourth rib <NUM> is connected to an inner side in the width direction W with respect to a connection portion between the main body upper surface portion <NUM> and the first rib <NUM>, and extends in the upper-lower direction Z and the front-rear direction FR. The other end of the second rib <NUM>, the other end of the third rib <NUM>, and the other end of the fourth rib <NUM> are aggregated and connected in the vicinity of a center inside the side bracket <NUM>, and form a first aggregated portion <NUM>.

One end of the fifth rib <NUM> is connected to the main body upper surface portion <NUM> and extends in the width direction W and the front-rear direction FR. One end of the sixth rib <NUM> is connected to the first aggregated portion <NUM> and extends in the width direction W and the front-rear direction FR. The other end of the fifth rib <NUM> and the other end of the sixth rib <NUM> are aggregated and connected in the abutting portion <NUM> to form a second aggregated portion <NUM>. The seventh rib <NUM> extends from the first aggregated portion <NUM> in a direction different from the sixth rib <NUM> in the width direction W and is connected to the abutting portion <NUM>.

In the second embodiment, by providing these ribs, strength of the side bracket <NUM> in the vehicle width direction W and the upper-lower direction Z is increased.

In the second embodiment, the following load paths are formed in the side bracket <NUM> as examples. That is, a first load path is formed through which a load input from the protruding end portion <NUM> is transmitted to the side frame <NUM> through the main body upper surface portion <NUM>, the first rib <NUM>, the second rib <NUM>, and the seventh rib <NUM>. Further, a second load path is formed through which the load input from the protruding end portion <NUM> is transmitted to the side frame <NUM> through the main body lower surface portion <NUM>, the third rib <NUM>, the first aggregated portion <NUM>, the sixth rib <NUM>, and the second aggregated portion <NUM>. Further, a second load path is formed through which the load input from the protruding end portion <NUM> is transmitted to the side frame <NUM> through the main body upper surface portion <NUM>, the fourth rib <NUM>, the first aggregated portion <NUM>, and the sixth rib <NUM>. Further, a third load path is formed through which the load input from the protruding end portion <NUM> is transmitted to the side frame <NUM> from the main body upper surface portion <NUM>, the fifth rib <NUM>, and the second aggregated portion <NUM>. Furthermore, a fourth load path is formed through which the load input from the protruding end portion <NUM> is transmitted to the bottom plate <NUM> through the main body upper surface portion <NUM>, the fourth rib <NUM>, the first aggregated portion <NUM>, the seventh rib <NUM>, and the support portion <NUM>.

The fourth rib <NUM>, the fifth rib <NUM>, and the sixth rib <NUM> are formed such that a cross-sectional shape in the upper-lower direction Z along the width direction W is circular. That is, a cylindrical passage Sw extending in the front-rear direction FR is formed by the fourth rib <NUM>, the fifth rib <NUM>, and the sixth rib <NUM> in the side bracket <NUM>. The cylindrical passage Sw is a passage for conveying a refrigerant that cools an in-vehicle device provided in the vehicle <NUM>.

Since the side bracket <NUM> includes the first rib <NUM> to the seventh rib <NUM> described above, an inside of the side bracket <NUM> is partitioned into the cylindrical passage Sw and spaces Sa, Sb, Sc, Sd, Se in a cross section in the upper-lower direction Z along the width direction W.

When the excessive load is input to the side bracket <NUM>, the spaces Sa, Sb, Sc, Sd, and Se are crushed by deformation or breakage of the first rib <NUM> to the fifth rib <NUM>. That is, the spaces Sa, Sb, Sc, Sd, and Se function as a buffer structure that absorbs the load transmitted to the side frame <NUM>.

Next, the rear side bracket 60R will be described.

The rear side bracket 60R includes a main body portion 61R that attaching the battery case <NUM> to the vehicle body, an abutting portion 62R that constitutes one surface of the main body portion 61R on a side frame <NUM> side and abuts against the outer surface <NUM> of the side frame <NUM>, and a support portion 63R that protrudes from a lower end of the abutting portion 62R and supports the battery case <NUM> from a lower side.

A first rib 71R, a second rib 72R, and a third rib 73R are provided inside the rear side bracket 60R.

The first rib 71R extends in the front-rear direction FR along the upper-lower direction Z. Further, the second rib 72R and the third rib 73R are disposed in a manner of partitioning an inside of the rear side bracket 60R in the upper-lower direction Z.

Although not shown in <FIG>, the rear side bracket 60R is also disposed such that end portions 72Re and 73Re respectively provided in the second rib 72R and the third rib 73R, which extend in the width direction W, on the side frame <NUM> side correspond to end portions of the frame ribs <NUM>, <NUM>, <NUM>, and <NUM> provided inside the side frame <NUM> on a rear side bracket 60R side.

Accordingly, similarly to the side bracket <NUM>, a load path is formed through which a load input to the rear side bracket 60R is transmitted to the side frame <NUM>.

First, effects of the rear side bracket 60R which is also provided in the battery case <NUM> according to the first embodiment will be described. The rear side bracket 60R includes the second rib 72R and the third rib 73R extending in the vehicle width direction W inside the rear side bracket 60R. Accordingly, the rear side bracket 60R is supported in the vehicle width direction W by the second rib 72R and the third rib 73R inside the rear side bracket 60R. Therefore, strength of the rear side bracket 60R in the vehicle width direction W is increased.

In the vehicle upper-lower direction Z, the second rib 72R and the third rib 73R of the rear side bracket 60R are disposed such that height positions of the end portions 72Re and 73Re thereof on the side frame <NUM> side are aligned with height positions of the end portions of the frame ribs <NUM>, <NUM>, <NUM>, and <NUM>, which are disposed inside the side frame <NUM>, on the rear side bracket 60R side.

Therefore, in the battery case <NUM>, the load path passes from the second rib 72R and the third rib 73R of the rear side bracket 60R to the frame ribs <NUM>, <NUM>, <NUM>, and <NUM> is formed. Therefore, the load input to the rear side bracket 60R from the outer side in the vehicle width direction W can be more reliably dispersed to the side frame <NUM>.

Further, in the vehicle upper-lower direction Z, the height positions of the end portion 72Re of the second rib 72R and the end portion 73Re of the third rib 73R of the rear side bracket 60R on the side frame <NUM> side are aligned with the height positions of the end portions of the frame ribs <NUM>, <NUM>, <NUM>, and <NUM>, which are disposed inside the side frame <NUM>, on the rear side bracket 60R side, and thus even on the rear side of the vehicle <NUM>, rigidity of the battery case <NUM> in the vehicle width direction W is increased, and the load input from a side of the vehicle <NUM> can be smoothly transmitted in the vehicle width direction W of the battery case <NUM>.

In the second embodiment, the first rib <NUM>, the second rib <NUM>, the third rib <NUM>, the fourth rib <NUM>, the fifth rib <NUM>, the sixth rib <NUM>, and the seventh rib <NUM> extending in the width direction W or the upper-lower direction Z are formed inside the side bracket <NUM>. This further increases the strength of the side bracket <NUM> in the vehicle width direction W and the upper-lower direction Z.

In the second embodiment, by providing the first rib <NUM> to the seventh rib <NUM>, a load path such as the first load path to the fourth load path is formed in the side bracket <NUM> as an example. Therefore, the load input from the protruding end portion <NUM> of the side bracket <NUM> can be more reliably dispersed to the side frame <NUM>.

In the upper-lower direction Z, a height position of the second aggregated portion <NUM> in the side bracket <NUM> is aligned with a height position of the end portion 14b on the side bracket <NUM> side of the frame rib <NUM> in the side frame <NUM>. The load path formed in this manner can smoothly transmit the load input from the side of the vehicle <NUM> in the vehicle width direction W of the battery case <NUM>.

In the battery case <NUM> according to the second embodiment, the spaces Sa, Sb, Sc, Sd, and Se that function as the buffer structure are formed inside the side bracket <NUM> by the first rib <NUM> to the seventh rib <NUM> provided therein. In such a structure, when the excessive load is input to the side bracket <NUM>, the spaces Sa, Sb, Sc, Sd, and Se are crushed, so that the excessive load input from the side of the vehicle <NUM> can be absorbed. Therefore, it is possible to prevent the excessive load from being transmitted to the side frame <NUM>.

In the second embodiment, the cylindrical passage Sw having a cylindrical shape is formed inside the side bracket <NUM>. When the passage has such a cylindrical shape, a stress is unlikely to concentrate, and strength of the passage is increased. Furthermore, it also contributes to strength improvement of the side bracket <NUM> as a whole.

As described above, according to the battery case <NUM> described above, the durability against the load input to the side surface of the vehicle <NUM> can be improved, and an accommodated battery can be more reliably protected.

Although the embodiments of the present invention have been described above, the above embodiments are merely a part of application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. Various changes and modifications may be made to the above embodiments within the scope of the matters described in the claims.

The curved portion 10C formed in the side frame <NUM> is not limited to one position. A position thereof can be appropriately changed according to a design of the battery case <NUM>. Curved portions may be formed at a plurality of positions of the side frame <NUM>.

The cross-sectional shapes of the side frame <NUM> and the cross member <NUM> are not limited to the shapes shown in <FIG> and <FIG>.

A position of the cylindrical passage Sw in the side bracket <NUM> is not limited to the position shown in <FIG>. Further, any one of the spaces Sa, Sb, Sc, Sd, and Se formed by partitioning the inside of the side bracket <NUM> by the first rib <NUM> - the seventh rib <NUM> may be used as the refrigerant passage.

Claim 1:
A battery case (<NUM>) that accommodates a battery for an electric vehicle (<NUM>), the battery case (<NUM>) comprising:
a pair of side frames (<NUM>) that constitute left and right side walls of the battery case (<NUM>) in a vehicle width direction (W) and extend along a vehicle front-rear direction (FR);
a cross member (<NUM>) that partitions an internal space of the battery case (<NUM>) in the vehicle front-rear direction (FR) and extends from one of the side frames (<NUM>) to the other side frame (<NUM>); and
a side bracket (<NUM>) that is fixed to an outer surface (<NUM>) of the side frame (<NUM>) and configured to attach the battery case (<NUM>) to a vehicle body (<NUM>), wherein
the side bracket (<NUM>) includes a bracket rib (<NUM>) extending in the vehicle width direction (W) inside the side bracket (<NUM>),
characterized in that:
the side frame (<NUM>) includes a frame rib (<NUM>, <NUM>, <NUM>, <NUM>) extending in the vehicle width direction (W) inside the side frame (<NUM>),
the cross member (<NUM>) includes a member rib (<NUM>, <NUM>, <NUM>, <NUM>) extending in the vehicle width direction (W) inside the cross member (<NUM>), and
an end portion (11a, 12a, 13a, 14a) of the frame rib (<NUM>, <NUM>, <NUM>, <NUM>) on a cross member side and an end portion (21e, 22e, 23e, 24e) of the member rib (<NUM>, <NUM>, <NUM>, <NUM>) on a side frame side are disposed in a manner of corresponding to each other in a vehicle upper-lower direction (Z).