Patent Description:
In recent years, from the viewpoint of an environmental impact, electric vehicles are under development also in the field of commercial vehicles such as trucks. It is desirable that a battery pack mounted in such an electric truck is arranged between frames in terms of securing side collision safety of the battery pack.

<CIT> discloses a vehicle having: a pair of side rails extending in a longitudinal direction of the vehicle; a battery pack that is mounted below the side rails and that is formed in a rectangular parallelepiped shape with a pair of side faces each facing in the longitudinal direction of the vehicle and with front and rearside faces having a long side that is orthogonal to the longitudinal direction of the vehicle and extends beyond the side rails in a vehicle width direction; and a vehicle battery pack support device.

<CIT> shows a body of a passenger car, which has a vehicle floor in the area of the passenger cell, which is laterally bounded by side sills.

On the inside of these side sills, a battery pack is secured by means of a vehicle battery pack support device.

<CIT> discloses a ladder frame for a truck in which a battery pack is secured within frame side members of the ladder frame by means of a vehicle battery pack retaining device.

However, there are various sizes of battery packs for running a vehicle and some of the battery packs are too large to fit between a pair of frames of the electric truck. In a case ofemploying such a battery pack, it is not possible to arrange the battery pack between frames.

In addition, there is a demand to employ a common battery pack used in passenger cars for electric trucks in order to reduce costs. However, in case of passenger cars, the battery pack is mounted inside a vehicle body, but in case of electric trucks, the battery pack is arranged so as to be exposed to the outside.

Under these circumstances, the present invention was made to provide a vehicle battery pack support device capable of securing torsional rigidity and side collision safety of a battery pack when a battery pack having a dimension that does not fit between frames of an electric truck is mounted.

The present invention was made to overcome at least some of the problems described above, and can be implemented as the following embodiments or application examples.

As described above, the vehicle battery pack support device has a structure in which the first brackets are longer than the long sides of the front side face and the rear side face of the battery pack, and cover the front side face and the rear side face to prevent an impact from being directly transferred to the battery pack even when the impact is applied from a lateral side in the vehicle width direction.

In addition, the second brackets cover end portions of the first brackets in the vehicle width direction, so that it is possible to improve torsional rigidity of the battery bracket and substantially prevent fragments or the like from directly reaching the battery pack even when an object collides from a lateral side in the vehicle width direction.

The battery bracket including the first brackets and the second brackets can be easily formed so as to fit the shape of the battery pack. Further, the battery bracket is coupled to the side rails via the frame bracket to support the battery pack, so that the battery pack that has a size larger than the distance between the frames of the electric truck can be easily mounted, and that torsional rigidity and side collision safety of the battery pack can be secured.

(<NUM>) In the vehicle battery pack support device according to the application example of the above configuration (<NUM>), the front first bracket includes: a first web that covers the side face of the battery pack facing a front side of the vehicle; the first top flange that is continuous with the first web and covers the top face; and the first bottom flange that is continuous with the first web and covers the bottom face, and the rear first bracket includes: a first web that covers the side face of the battery pack facing a rear side of the vehicle; the first top flange that is continuous with the first web and covers the top face; and the first bottom flange that is continuous with the first web and covers the bottom face. This configuration can further improve torsional rigidity of the battery bracket.

An embodiment of the present invention will be described in detail below with reference to the drawings. <FIG> is a schematic top view illustrating an overall configuration of a vehicle including a vehicle battery pack support device according to the present embodiment. The shapes of components described below are, basically, horizontally symmetrical with respect to the center of the vehicle <NUM> in a vehicle width direction (Y direction in the drawings). Therefore, basically, only one of left and right components is described in the following description, but the other components which are symmetrical to their counterparts have the same shapes as their counterparts.

The vehicle <NUM> includes a motor (electric motor) (not shown) as a driving power source, and is, for example, a so-called electric vehicle. In the present embodiment in particular, the vehicle <NUM> is a truck vehicle provided with a cab <NUM> and a cargo box <NUM>. The cab <NUM> is mounted on a chassis frame, and is adapted for a driver to board. The cargo box <NUM> is disposed behind the cab <NUM> and is configured to be capable of carrying the cargo. In the drawing, the cab <NUM> and the cargo box <NUM> are outlined with a dotted line.

The vehicle <NUM> may also be a hybrid car including an engine in addition to a motor as the driving power source. Further, the vehicle <NUM> is not limited to the truck vehicle, and may be any other commercial vehicle including a battery for driving the vehicle.

The chassis frame is what is called a ladder frame including a pair of side rails <NUM> and 3R extending in a longitudinal direction (X direction in the drawings) of the vehicle, and a plurality of cross members 3a, 3b, 3c, and 3d arranged between the side rails <NUM> and 3R along the vehicle width direction (Y direction in the drawings). The side rails are simply referred to as side rails without specifying left and right side rails. The chassis frame having such a configuration can achieve both of static strength for enduring a weight of the truck vehicle and dynamic strength (fatigue strength) for enduring repetitive load application caused by road surface vibrations or the like during traveling.

Further, front wheels <NUM> are suspended at a front portion of the chassis frame and rear wheels <NUM> are suspended at a rear portion of the chassis frame. A driving force is transmitted to these wheels by the motor (not shown) such that the vehicle <NUM> can travel. A battery for feeding power to the motor as such a driving power source is mounted in the vehicle <NUM> via a support device <NUM>.

The battery has a configuration in which a battery unit (not shown) including a plurality of secondary battery cells is housed in a battery pack <NUM> which is a casing. The battery pack <NUM> is supported on the side rails 3R and <NUM> constituting the chassis frame, via the support device <NUM> as illustrated in <FIG>.

The support device <NUM> includes a battery bracket <NUM> and a frame bracket <NUM>.

The battery bracket <NUM> includes a pair of front first bracket 21A and rear first bracket 21B (also collectively referred to as first brackets 21A and 21B), and a pair of left second bracket <NUM> and right second bracket 22R (also collectively referred to as second brackets <NUM> and 22R).

A front portion and a rear portion of the second bracket <NUM> of the battery bracket <NUM> are coupled to and supported on the side rail <NUM> via the frame bracket <NUM>, and a front portion and a rear portion of the second bracket 22R of the battery bracket <NUM> are coupled to and supported on the side rail 3R via the frame bracket <NUM>.

<FIG> is an exploded perspective view of the battery pack and the battery bracket. The battery pack <NUM> is formed in a rectangular parallelepiped shape and has a front side face 2a which is a rectangular side face facing a front side of the vehicle, and a rear side face 2b which is a rectangular shape facing a rear side of the vehicle. The battery pack <NUM> is arranged along the vehicle width direction (Y direction in the drawings) so that long sides of the front side face 2a and the rear side face 2b are orthogonal to the longitudinal direction (X direction in the drawings) of the vehicle. The battery pack <NUM> is dimensioned so that both end portions of the battery pack <NUM> in the vehicle width direction extend beyond outer side faces of the side rails <NUM> and 3R in the vehicle width direction. A length L2 of each of the long sides of the front side face 2a and the rear side face 2b is larger than a length L1 between the side rails <NUM> and 3R.

An under cover <NUM> is a member on which the battery pack <NUM> is directly placed, and is implemented by, for example, a plate-shaped member. The under cover <NUM> is a cover that simply covers a bottom face of the battery pack <NUM>, and it is the first brackets 21A and 21B that directly hold the battery pack <NUM>.

The front first bracket 21A includes a first web 21Aw for covering the front side face 2a of the battery pack <NUM> in the drawing. Further, a first top flange 21At for covering a portion of a top face which is continuous with the front side face 2a of the battery pack <NUM>, and a first bottom flange 21Ab for covering a portion of the bottom face which is continuous with the front side face 2a are formed so as to be vertically continuous with the first web 21Aw. In other words, the first top flange 21At and the first bottom flange 21Ab are arranged so that flat surface portions thereof face each other in a vehicle height direction (Z direction in the drawings). Thus, the front first bracket 21A is formed in a substantial "U" shape having a cross section that is open toward the rear side of the vehicle.

Similarly, the rear first bracket 21B includes a first web 21Bw for covering the rear side face 2b of the battery pack <NUM>. Further, the rear first bracket 21B includes a first top flange 21Bt for covering a portion of the top face which is continuous with the rear side face 2b of the battery pack <NUM>, and a first bottom flange 21Bb for covering a portion of the bottom face which is continuous with the rear side face 2b. In other words, the first top flange 21Bt and the first bottom flange 21Bb of the rear first bracket 21B are arranged so that flat surface portions thereof face each other in the vehicle height direction (Z direction in the drawings). Thus, the rear first bracket 21B is formed in a substantial "U" shape having a cross section that is open toward the front side of the vehicle.

The open side of the first bracket 21A and the open side of the first bracket 21B face each other, and the first brackets 21A and 21B support the battery pack <NUM> while sandwiching the battery pack <NUM> therebetween in the longitudinal direction of the vehicle.

The left second bracket <NUM> includes a second web 22Lw covering open faces of left end portions of the first brackets 21A and 21B in the vehicle width direction. Further, the second web 22Lw has, at an upper end thereof, a second top flange 22Lt which extends across the first top flanges 21At and 21Bt included in the first brackets 21A and 21B, respectively, and which is coupled to outer sides of the first top flanges 21At and 21Bt of the first brackets 21A and 21B. Similarly, the second web 22Lw has, at a lower end thereof, a second bottom flange 22Lb which extends across the first bottom flanges 21Ab and 21Bb included in the first brackets 21A and 21B, respectively, and which is coupled to outer sides of the first bottom flanges 21Ab and 21Bb of the first brackets 21A and 21B.

The second top flange 22Lt and the second bottom flange 22Lb of the left second bracket <NUM> are each formed to have a larger dimension in the vehicle width direction at an end portion in the longitudinal direction of the vehicle than that of a central portion. Specifically, a central portion of each of the second top flange 22Lt and the second bottom flange 22Lb in the longitudinal direction of the vehicle is cut out in an arc shape. By doing so, torsional rigidity of a battery pack support device is improved while achieving weight reduction.

The right second bracket 22R is horizontally symmetrical to the left second bracket <NUM> and has a similar configuration, and thus a description thereof will be omitted.

In the drawing, when portions connected by a dot-and-dash line are aligned with each other, the battery bracket <NUM> surrounds four side faces and portions of the top face and the bottom face of the battery pack <NUM>, like a box. The battery bracket <NUM> surrounding the battery pack <NUM> as described above is coupled to the side rails <NUM> and 3R via the frame bracket <NUM>.

Referring to <FIG> is a cross-sectional view taken along line A-A of <FIG>. Hereinafter, a left side portion of the support device <NUM> suspended on the side rail <NUM> will be described by way of example with reference to the drawing. A right side portion of the support device <NUM> suspended on the side rail 3R is horizontally symmetrical to the left side portion of the support device <NUM> and has a similar configuration, and thus a detailed description thereof will be omitted.

As described above, the battery pack <NUM> is placed on the under cover <NUM>, and the front portion and the rear portion of the battery pack <NUM> are covered by the first brackets 21A and 21B, respectively. Specifically, the first webs 21Aw and 21Bw and the first top flanges 21At and 21Bt of the first brackets 21A and 21B are in contact with corresponding faces of the battery pack <NUM> (the front side face 2a, the rear side face 2b, and a portion of the top face), respectively, and the first bottom flanges 21Ab and 21Bb are in contact with the under cover <NUM>.

In addition, the left second bracket <NUM> covers the under cover <NUM> and the first brackets 21A and 21B from the outside while leaving a space S between the left second bracket <NUM> and a left side face of the battery pack <NUM> in the vehicle width direction. The size of the space S can be adjusted by changing dimensions of the second top flange 22Lt and the second bottom flange 22Lb of the left second bracket <NUM> in the vehicle width direction, and can be adjusted also by changing dimensions of the first brackets 21A and 21B in the vehicle width direction.

The second bottom flange 22Lb of the left second bracket <NUM> is in contact with the first bottom flanges 21Ab and 21Bb of the first brackets 21A and 21B. The second bottom flange 22Lb of the left second bracket <NUM>, the first bottom flanges 21Ab and 21Bb of the first brackets 21A and 21B, and the under cover <NUM> are coupled to one another with a plurality of bolts <NUM> (only one bolt is illustrated in <FIG>).

The second top flange 22Lt of the left second bracket <NUM> is in contact with the first top flanges 21At and 21Bt of the first brackets 21A and 21B, and the frame bracket <NUM>. The second top flange 22Lt of the left second bracket <NUM>, the first top flanges 21At and 21Bt of the first brackets 21A and 21B, and a lower portion 30c of the frame bracket <NUM> are coupled to one another with a plurality of bolts <NUM> (only one bolt is illustrated in <FIG>).

The frame bracket <NUM> is, for example, a member including an upper portion 30a, a central portion 30b, and the lower portion 30c, and having an "S" shaped cross section as illustrated in the drawing. A rib (not shown) is provided on a side face of the frame bracket <NUM> to increase strength. The upper portion 30a of the frame bracket <NUM> is coupled to a mount <NUM> with a plurality of bolts <NUM> (only one bolt is illustrated in <FIG>).

The mount <NUM> is a member connecting the frame bracket <NUM> and the side rail <NUM> to each other. For example, the mount <NUM> is coupled to a web 3Lw of the side rail <NUM> with a plurality of bolts <NUM> (only two bolts are illustrated in <FIG>). The mount <NUM> is, for example, a rubber mount, and includes an elastic material such as rubber therein to elastically hold the frame bracket <NUM> with respect to the side rail <NUM>.

As described above, the support device <NUM> has a structure in which the first brackets 21A and 21B having rigidity substantially equivalent to the chassis frame are longer than the long sides of the front side face 2a and the rear side face 2b of the battery pack <NUM>, and cover the front side face 2a and the rear side face 2b to prevent an impact from being directly transferred to the battery pack <NUM> even when the impact is applied from a lateral side in the vehicle width direction.

In addition, the second brackets <NUM> and 22R cover end portions of the first brackets 21A and 21B in the vehicle width direction, so that it is possible to improve torsional rigidity of the battery bracket <NUM> and substantially prevent fragments or the like from directly reaching the battery pack <NUM> even when an object collides from a lateral side in the vehicle width direction.

The battery bracket <NUM> including the first brackets 21A and 21B and the second brackets <NUM> and 22R can be easily formed so as to fit the shape of the battery pack <NUM>. Further, the battery bracket <NUM> is coupled to the side rails <NUM> and 3R via the frame bracket <NUM> to support the battery pack <NUM>, so that the battery pack <NUM> that has a size larger than the distance between the side rails <NUM> and 3R of the electric truck can be easily mounted, and that torsional rigidity and side collision safety of the battery pack <NUM> can be secured.

Particularly, in the front first bracket 21A, the first top flange 21At and the first bottom flange 21Ab are integrally and continuously formed with the first web 21Aw covering the front side face 2a of the battery pack <NUM>, so that it is possible to cushion an impact applied from the front side of the vehicle, and improve front collision safety of the battery pack.

Further, the second brackets <NUM> and 22R include the second top flanges 22Lt and 22Rt coupled to the first top flanges 21At and 21Bt, and the second bottom flanges 22Lb and 22Rb coupled to the first bottom flanges 21Ab and 21Bb of the first brackets 21A and 21B, and thus have a structure of sandwiching and holding the first brackets 21A and 21B. As a result, it is possible to improve torsional rigidity of the battery bracket <NUM>.

In addition, the second top flanges 22Lt and 22Rt and the second bottom flanges 22Lb and 22Rb of the second brackets <NUM> and 22R are each formed to have a larger dimension in the vehicle width direction at an end portion in the longitudinal direction of the vehicle than that of a central portion. It is thus possible to reduce weight of the battery bracket <NUM> and secure torsional rigidity of the battery bracket <NUM>.

Further, the space S is formed between the second webs 22Lw and 22Rw of the second brackets <NUM> and 22R, and side faces of the battery pack <NUM> in the vehicle width direction. It is thus possible to substantially prevent a situation in which even when the second brackets <NUM> and 22R are deformed due to an impact applied from the side of the vehicle, the second brackets <NUM> and 22R directly come into contact with the battery pack <NUM> and transfer the impact.

Although the description of the embodiment of the vehicle battery pack support device of the present invention ends here, the present invention is not limited to this embodiment.

For example, <FIG> is a schematic top view of a vehicle including a vehicle battery pack support device according to another embodiment. According to this embodiment, as illustrated in <FIG>, three battery packs 2A, 2B, and 2C are arranged in a longitudinal direction of the vehicle and supported by support devices 10A, 10B, and 10C, respectively.

The battery pack 2B and the support device 10B arranged at the center in the longitudinal direction of the vehicle are similar to those of the embodiment described above, whereas the battery pack 2A and the support device 10A arranged at a front side of the vehicle each have a longer dimension in the vehicle width direction and are offset toward the right side of the vehicle. The battery pack 2C and the support device 10C arranged at a rear side of the vehicle each have a longer dimension in the longitudinal direction of the vehicle than those of the central battery pack 2B and the support device 10B.

The support devices 10A, 10B, and 10C can easily fit the shapes or layouts of the battery packs 2A, 2B, and 2C, respectively. It is thus possible to obtain similar effects to those of the embodiment described above.

Further, the front and rear first brackets 21A and 21B of the battery bracket <NUM> are paired according to the embodiment described above, but are not limited thereto. For example, two bracket members each having an "L" shaped cross section may be vertically combined to function as one of the first brackets. Alternatively, the pair of front and rear first brackets 21A and 21B may be integrally formed in a cylindrical shape. This configuration further improves torsional rigidity of the battery bracket <NUM>.

Claim 1:
A vehicle (<NUM>) having: a pair of side rails (<NUM>, 3R) extending in a longitudinal direction of the vehicle (<NUM>); a battery pack (<NUM>) that is mounted below the side rails (<NUM>, 3R) and that is formed in a rectangular parallelepiped shape with a pair of side faces each facing in the longitudinal direction of the vehicle (<NUM>) and with front and rearside faces (2a, 2b) having a long side that is orthogonal to the longitudinal direction of the vehicle (<NUM>) and extends beyond the side rails (<NUM>, 3R) in a vehicle width direction; and a vehicle battery pack support device, the vehicle battery pack support device comprising a battery bracket (<NUM>) for housing the battery pack (<NUM>); and a frame bracket (<NUM>) for coupling the side rails (<NUM>, 3R) and the battery bracket (<NUM>), characterized by the battery bracket (<NUM>) including a front first bracket (21A) and a rear first bracket (21B) covering the front and rear side faces (2a, 2b) of the battery pack (<NUM>), a portion of a top face that is continuous with the front and rear side faces (2a, 2b), and a portion of a bottom face that is continuous with the front and rear side faces (2a, 2b), the front and rear first brackets (21A, 21B) having a dimension in the vehicle width direction which is equal to or larger than the long side of the battery pack (<NUM>), and
a left second bracket (<NUM>) and a right second bracket (22R) covering end portions of the front first bracket (21A) and the rear first bracket (21B) in the vehicle width direction and coupled to the frame bracket (<NUM>), the front first bracket (21A) and the rear first bracket (21B), the left second bracket (<NUM>) and the right second bracket (22R) forming a box-like shape.