Electric vehicle

An electric vehicle has a battery pack under a floor panel. The battery pack includes battery modules having an electricity storage function, a first case holding the battery modules therein, and a power shut-off mechanism temporarily interrupting the electric power of the battery modules. The floor panel includes an access port communicating between the inside and outside of a cabin. The battery pack further includes a second case extending upward from an upper surface of the first case adjacent to the floor panel and including the power shut-off mechanism therein. The second case has an opening for allowing the access to the power shut-off mechanism from the outside of the second case, the opening being oriented in an access direction where the power shut-off mechanism is accessed from the access port toward the opening.

This application claims priority from Japanese Patent Application No. 2010-292769; filed Dec. 28, 2010, the disclosure of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a vehicle having a battery pack as a power source outside of a cabin and, more particularly, to an arrangement and a structure of a service plug of the battery pack.

BACKGROUND OF THE INVENTION

An electric vehicle (referred to as “EV”) needs to be equipped with a large capacity battery to ensure a sufficient running distance for practical use. However, the size of the battery itself is increased and thus there is not sufficient space inside a cabin for the battery. Accordingly, the battery is sometimes mounted outside of the cabin, for example, under a floor of the vehicle.

As shown inFIG. 5, battery modules4, each of which is formed by combining battery cells24, are surrounded by a battery pack enclosure5made of metal or resin to form a battery pack3. When the battery pack enclosure5is mounted outside of the cabin, the battery pack enclosure5is waterproofed to prevent electric leakage.

Also, as shown inFIG. 5, an electricity control circuit25such as an electricity connection circuit and a control unit is provided inside the battery pack3. Furthermore, a power shut-off mechanism6serving as a service plug for ensuring working efficiency during maintenance is provided by an on-off switch (not shown) at such a position as to divide the voltage of the battery modules4connected in series.

BRIEF SUMMARY OF THE INVENTION

FIGS. 6 and 7show a structure of a conventional battery pack103provided under a floor panel102of a vehicle101. The battery pack103is generally provided along the floor panel102of the vehicle101for securing a certain capacity and distance from the ground (referred to as “ground height”).

Furthermore, the battery pack103is provided with a service plug (not shown) for temporarily interrupting the electrical power. For example, the service plug is integrated with the battery pack103for reducing the number of assembly steps of the vehicle. The service plug is provided on the upper surface of the battery pack103facing the floor panel102of the vehicle101such that the electrical power of the battery pack103can be interrupted from the side close to a cabin107during maintenance of the vehicle101.

The service plug is covered with a service plug lid111to prevent electric leakage of the battery pack103caused by it being wet with water. However, when the vehicle101, including such a battery pack103, travels in the rain or travels on a water-covered road, water may flow on the upper surface of the battery pack103from the vehicle front side toward the vehicle rear side as shown by an arrow inFIG. 7. At this time, the service plug and a service plug lid109provided on the upper surface of the battery pack103may become wet, thereby causing electric alleakage.

In particular, when the floor panel of the vehicle has a shape substantially parallel to the ground, the upper surface of the battery pack is similarly formed to be flat. Accordingly, the service plug provided on the upper surface of the battery pack is far more likely to be wet with water. A waterproof seal or the like may be attached to the service plug lid to prevent water from entering into the battery pack through the service plug lid. However, the service plug lid may easily become wet at any time. Thus, the breakdown of the battery pack may easily occur, which is not desirable.

To solve the above-described problem, JP2009-83601A is known. JP2009-83601A discloses that an opening part for a service plug formed on a battery case of a battery pack provided under a floor panel of a vehicle and a hole formed on the floor panel are connected by an elastically deformable and waterproof boot member, and a waterproof space is provided inside the boot member.

However, JP2009-83601A has inconveniences as follows.(1) Since the battery pack and the vehicle are connected by the boot member, removing the battery pack from the vehicle requires troublesome work. Furthermore, the boot member may be damaged when the battery pack is removed from or attached to the vehicle. It is difficult to find such damage, and thus the service plug may become wet.(2) A distance between the opening part for the service plug and the hole formed on the floor panel is restricted to some extent. Since the length of the boot member is increased when the distance is increased, it becomes difficult to check the service plug from an inner side of a cabin, and also the maintenance performance is deteriorated. At this time, a structure for allowing the upper surface of the battery pack to be close to the floor panel is required. However, when such a structure is provided for each vehicle, it is difficult to use the same battery pack for various vehicles having different vehicle body structures, which decreases versatility.

The present invention has been made in view of the above-described circumstances. It is an object of the present invention to provide a structure capable of facilitating access to a service plug from an inner side of a cabin while preventing the service plug from becoming wet, and allowing a battery pack to have broad utility so that the battery pack is applicable to various vehicles.

To eliminate the above-described inconveniences, an electric vehicle of the present invention includes: a cabin; a floor panel defining a bottom surface of the cabin; and a battery pack mounted under the floor panel and serving as a power source of the vehicle, the battery pack including battery modules having an electricity storage function, a first case holding the battery modules therein, and a power shut-off mechanism temporarily interrupting electric power of the battery modules, the floor panel having an access port communicating between an inside and an outside of the cabin, characterized in that the battery pack further includes a second case extending upward from an upper surface of the first case adjacent to the floor panel and including the power shut-off mechanism therein, and the second case has an opening for allowing access to the power shut-off mechanism from the outside of the second case, the opening being oriented in an access direction where the power shut-off mechanism is accessed from the access port toward the opening.

According to the above-described structure, a service plug can be protected from becoming wet by water splash of the battery pack. Also, the occurrence of breakdown of the battery pack can be reduced. In particular, the service plug can be prevented from becoming wet with water flowing on the upper surface of the battery back, which helps to reduce the occurrence of the breakdown of the battery pack.

Furthermore, the service plug is provided above the upper surface of the battery pack and an opening surface of an opening part for the service plug is oriented in an access direction where the service plug is accessed. The access port lies on an extension of the access direction. Thus, the access to the service plug from the inner side of the cabin can be easy.

Also, the vehicle and the battery pack are not connected according to a structure for preventing the service plug from becoming wet. Accordingly, the battery pack is easily removed from the vehicle.

Furthermore, by changing only a service plug enclosure, the battery pack is applicable to various vehicles having different shapes. Thus, the battery pack can have broad utility.

DETAILED DESCRIPTION OF THE INVENTION

The present invention now will be described more fully hereinafter in which embodiments of the invention are provided with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

FIGS. 1 to 5show an embodiment of the present invention. InFIGS. 1 to 5, reference numeral1denotes an electric vehicle (simply referred to as “vehicle”), reference numeral2denotes a floor panel of the electric vehicle1, and reference numeral3denotes a battery pack.

The electric vehicle1includes the battery pack3serving as a power source of the vehicle1provided under the floor panel2of the vehicle1.

As shown inFIG. 5, the battery pack3includes battery modules4having an electricity storage function, a first case (referred to as “battery pack enclosure”)5holding the battery modules4therein, and a power shut-off mechanism (referred to as “service plug”)6temporarily interrupting the electrical power of the battery modules4. The floor panel2includes an access port8communicating between the inside of a cabin7and the outside of the cabin7of the vehicle1.

The battery pack3includes a second case (referred to as “service plug enclosure”)9extending upward on the surface of the first case5facing the floor panel2. The second case9includes the power shut-off mechanism6therein and an opening10allowing the access to the power shut-off mechanism6from the outside of the second case9. The opening surface of the opening10is opposite to the access direction where the power shut-off mechanism6is accessed, while the access port8lies on an extension of the access direction.

More specifically, as shown inFIGS. 1 and 2, the second case9is provided on the upper surface of the first case5to have a predetermined height. The power shut-off mechanism6for temporarily interrupting the electric power of the battery pack3is provided inside the second case9.

As shown inFIG. 4, the opening10for the power shut-off mechanism6, which allows the access to the power shut-off mechanism6serving as the service plug from the outside, is provided on the upper side of the second case9.

The opening surface of the opening10for the power shut-off mechanism6is provided opposite to the access direction where the power shut-off mechanism6is accessed. Furthermore, the access port8lies on the extension of the access direction.

Thus, the power shut-off mechanism6can be protected from becoming wet due to water splashing on the battery pack3, and therefore the occurrence of breakdown of the battery pack3can be reduced. In particular, the power shut-off mechanism6can be prevented from becoming wet with water flowing on the upper surface of the battery pack3, which helps to reduce the occurrence of breakdown of the battery pack1

The power shut-off mechanism6is provided above the upper surface of the battery pack3. The opening surface of the opening10for the power shut-off mechanism6is provided opposite to the access direction where the power shut-off mechanism6is accessed, and the access port8lies on the extension of the access direction. Thus, the access to the power shut-off mechanism6from the inner side of the cabin7of the vehicle1can be easy.

The vehicle1and the battery pack3are not connected according to the structure for preventing the power shut-off mechanism6from becoming wet. Thus, the battery pack3is easily removed from the vehicle1. Also, by changing only the second case9, the battery pack3is applicable to various vehicles having different body shapes, and thus the battery pack3can have broad utility.

The second case9includes a second case lid (referred to as “service plug lid”)11covering the opening10on the upper side. The access port8is positioned above the surface of the surrounding floor panel2. A vertical wall12extends downward in the vertical direction of the vehicle from the vicinity of the surface having the access port8. The lower end of the vertical wall12is connected to the surface of the floor panel2surrounding the lower end. The second case lid11is located within a space13defined by the surface having the access port8and the vertical wall12.

More specifically, the normal direction of the opening surface of the opening10for the power shut-off mechanism6is directed to the access port8. The power shut-off mechanism6is provided along the opening surface of the opening10for the power shut-off mechanism6and is inclined relative to the horizontal direction of the vehicle1. The power shut-off mechanism6is positioned to allow the access to the power shut-off mechanism6through the opening10for the power shut-off mechanism6for operation.

The second case lid11covering the opening surface of the opening10for the power shut-off mechanism6is fixed to the second case9by a fastening member14such as a bolt. The opening10for the power shut-off mechanism6is covered with the second case lid11at any other time but maintenance of the battery pack3to prevent the access to and water splashing on the power shut-off mechanism6.

When the battery pack3is attached to the vehicle, the second case9is attached to the vehicle such that the front-rear and right-left periphery of the second case9is positioned in an area defined by a left side frame15L and a right side frame15R of the vehicle and first and second cross members16and17which are cross members located sequentially from the front side toward the rear side. Incidentally, the battery pack3is attached to the rear side of the first cross member16by a first attachment bracket18and is attached to the lower side of the second cross member17by a second attachment bracket19.

Furthermore, the second case9is vertically partitioned by the floor panel2of the vehicle1and the upper surface of the first case5, and accordingly, is disposed in a closed space. Thus, the power shut-off mechanism6can be protected from becoming wet.

The power shut-off mechanism6is accessed from the inner side of the cabin7through the access port8provided on the floor panel2. The access port8is covered with a front seat20at any time other than when performing maintenance on the battery pack3. As shown inFIG. 2, the power shut-off mechanism6can be accessed through the access port8by rotating the front seat20backwardly at the time of maintenance of the battery pack3.

Furthermore, the access port8is positioned above the periphery of the floor panel2on which the access port8is provided. More specifically, as shown inFIG. 3, the vertical wall12extending upwardly is provided on the periphery of the access port8. Since the access port8is positioned above the surrounding floor panel2in the vehicle, the space13is provided by the surface having the access port8and the vertical wall12surrounding the access port8as shown inFIG. 3.

In the present invention, the second case lid11is located inside the space13. Since the second case lid11is positioned above the floor panel2provided on the front side of the space13, the second case lid11positioned above the floor panel2provided on the front side of the space13can be prevented from becoming wet.

Also, even when the vehicle1travels on a water-covered road, air is accumulated within the space13and therefore the second case lid11and the power shut-off mechanism6can be protected from becoming wet. The space13defined by the surface having the access port8and the vertical wall12surrounding the access port8is positioned above the surrounding floor panel2. Accordingly, even when water arrives at the surrounding floor panel2, water immersion can be alleviated because air is accumulated within the space13. Also, by positioning the second case lid11in the space13, the power shut-off mechanism6can be protected from becoming wet.

At least part of the opening10in the horizontal direction of the vehicle is provided on the rear side of an opening part21of the access port8, and an accessory component22is provided on the front side of the second case9. The second case9is offset on the rear side of the vehicle relative to the opening part21of the access port8. At this time, at least part of the opening10for the power shut-off mechanism6is positioned on the rear side of the access port8. Also, the upper portion of the second case9having the opening10for the power shut-off mechanism6for allowing the access to the power shut-off mechanism6is inclined toward the access port8in the horizontal direction of the vehicle.

A first purpose of adopting the above-described structure is to allow the front seat18serving as the lid of the access port8on the upper side of the access port8to be inclined toward the rear side of the vehicle. The front seat18is inclined toward the rear side of the vehicle to allow the access to the power shut-off mechanism6from the upper and front side of the access port8. The upper portion of the second case9having the opening10for the power shut-off mechanism6is directed to the upper and front side of the access port8in view of the access direction. More specifically, the upper portion of the second case9is inclined to have an approximately right angle α relative to a bottom surface of the front seat18when the front seat18is inclined backwardly.

A second purpose is to allow the access to a plurality of components through the access port8. The accessory component is provided on the front side of the second case9, and the accessory component22can be accessed through the access port8.

Furthermore, a third purpose is to prevent the second case9from becoming wet directly. As shown inFIG. 4, the accessory component22is provided on the front side of the second case9to receive water delivered on the upper surface of the first case5from the front side of the vehicle. Thus, the second case9can be prevented from becoming wet directly, and therefore the risk of breakdown of the battery pack3can be reduced. Thus, the access to the power shut-off mechanism6and the accessory component22from the inner side of the cabin7of the vehicle1can be allowed, while the second case9can be prevented from becoming wet directly by the accessory component22positioned on the front side of the power shut-off mechanism6.

According to the above-described structure, the following advantages can be obtained.

Since the second case9is protruded from the upper surface of the first case5and the opening10for the power shut-off mechanism6is positioned above the upper surface of the first case5, the power shut-off mechanism6can be protected from becoming wet with water flowing on the upper surface of the first case5.

Since the periphery of the second case9is disposed in the area partitioned by the left side frame15L and the right side frame15R of the vehicle1and the first and second cross members16and17while the battery pack3is attached to the vehicle1, the second case9can be prevented from becoming wet directly.

The access port8provided on the floor panel2is positioned above the surrounding floor panel2, and the vertical wall12horizontally extends around the access port8. Since the space is formed by the surface having the access port8and the vertical wall12and the second case lid11covering the opening10for the power shut-off mechanism6is disposed inside the space13, the power shut-off mechanism6can be protected from becoming wet.

Furthermore, the upper portion of the second case9having the opening10for the power shut-off mechanism6is directed to the upper and front side of the access port8. Even when the access port8cannot be completely opened by removing the member covering the access port8, the power shut-off mechanism6is accessible and operable.

The second case9can be offset to the rear side of the vehicle relative to the access port8and the accessory component22and the like can be disposed on the front side of the second case9. The access to the accessory component22through the access port8is possible.

Since the accessory component22positioned on the front side of the second case9receives the water flowing from the front side of the vehicle, the second case9can be prevented from becoming wet directly. Furthermore, the maintenance of the accessory component22positioned on the front side of the second case9can be performed from the inner side of the cabin7of the vehicle1.

By changing only the second case9, the same battery pack3can be applied to various vehicles. The battery pack3can have broad utility. Also, since it is not necessary that the battery pack3and the second case9be removed, a connection part23for connecting the second case9and the battery pack3can have a sealing structure for preventing water splashing and thus high water-proofness can be obtained.

For example, the present invention can be applied to not only an electric vehicle but also to a vehicle including a battery pack outside of a cabin such as a hybrid electric vehicle (referred to as “HEV”) and a fuel cell electric vehicle (referred to as “FCEV”). At this time, the form of a service plug is not particularly limited. For example, the service plug may be a component having an on-off function such as a plug or a breaker switch.