Battery cooling structure

A battery cooling structure includes: a battery provided in a luggage room of a vehicle; an air intake duct, including an air inlet open in a vehicular cabin, for supplying air in the vehicular cabin to the battery as cooling air; and a partition panel standing away from a rear seat with a clearance therebetween so as to section the luggage room and the vehicular cabin and provided with a duct hole in which the air intake duct is inserted. The partition panel is provided with an air exhaust hole for exhausting air in the luggage room to the vehicular cabin. The air exhaust hole is formed at a location spaced away from the duct hole. Such a configuration provides a battery cooling structure suppressing an adverse effect caused by exhaust of heated cooling air.

TECHNICAL FIELD

The present invention generally relates to a battery cooling structure, more particularly, a battery cooling structure installed in a luggage room of a vehicle.

BACKGROUND ART

Regarding conventional battery cooling structures, for example, Japanese Patent Laying-open No. 2004-1683 (Patent Document 1) discloses a vehicular battery cooling structure to prevent deterioration of battery characteristics and short life thereof. The vehicular battery cooling structure disclosed in Patent Document 1 includes an air intake duct connected to a battery pack, and an air sending fan distributing cooling air to the air intake duct in order to cool the battery pack. The air intake duct is provided with an air inlet located above a tonneau cover for covering a luggage placed in a luggage room.

Further, Japanese Patent Laying-open No. 5-169981 (Patent Document 2) discloses a device, provided in an electric car, for cooling a battery mounted therein by means of external air drawn in from a front end portion of the car body. In Patent Document 2, the electric car is provided with a hollow side frame extending from the front end portion to the rear end portion of the car body. The side frame has a front end portion in which an opening is provided to draw in the external air therethrough, and the external air thus drawn in passes through a battery storage room and thereafter is exhausted from an opening provided in the rear end portion of the side frame.

Further, Japanese Patent Laying-open No. 2006-182044 (Patent Document 3) discloses a high voltage battery unit mounting vehicular structure by which a high voltage battery having a particularly large capacitance can be mounted on a vehicle. In Patent Document 3, the high voltage battery is disposed on a rear floor panel of the rear portion of a fuel battery vehicle.

Furthermore, Japanese Patent Laying-open No. 2002-231321 (Patent Document 4) discloses a vehicular battery cooling device achieving improved cooling efficiency without complicating the structure of an air outlet of an air exhaust duct. In Patent Document 4, the air outlet of the air exhaust duct is provided between a deck side trim and an outer body to exhaust the air after cooling the battery.

In Patent Document 1 described above, air in the vehicular cabin is introduced into the luggage room as cooling air to cool the battery pack generating heat due to charging and discharging. In this case, continuous airflow from the vehicular cabin to the luggage room causes internal pressure drop in the vehicular cabin, whereby the air in the luggage room may be brought back to the vehicular cabin. The air in the luggage room has a high temperature due to influences of the battery pack generating heat and the cooling air exhausted from the battery pack. When such high temperature air is brought back to the vehicular cabin, an occupant in the vehicular cabin may feel unpleasant about the flow of such air, or the high temperature air may be drawn into the luggage room again to decrease the cooling efficiency of the battery pack.

DISCLOSURE OF THE INVENTION

An object of the present invention is to solve the above-described problems, and to provide a battery cooling structure for suppressing an adverse effect resulting from exhaust of heated cooling air.

A battery cooling structure according to the present invention includes: a battery provided in a luggage room of a vehicle; an air intake duct, including an air inlet open in a vehicular cabin, for supplying air in the vehicular cabin to the battery as cooling air; and a partition panel standing away from a rear seat with a clearance therebetween so as to section the luggage room and the vehicular cabin and provided with a duct hole in which the air intake duct is inserted. The partition panel is provided with an air exhaust hole for exhausting air in the luggage room to the vehicular cabin. The air exhaust hole is formed at a location spaced away from the duct hole.

According to the battery cooling structure thus configured, in the partition panel standing away from the rear seat with the clearance therebetween, the air exhaust hole is formed. Accordingly, the air exhausted from the luggage room via the air exhaust hole flows in the clearance between the rear seat and the partition panel and is then brought back to the vehicular cabin. This causes dispersion of the air, and then the air is brought back to the vehicular cabin. Hence, an occupant in the vehicular cabin can be prevented from feeling unpleasant about the high temperature air. Further, the air exhaust hole is formed at the location spaced away from the duct hole. Accordingly, the high temperature air exhausted from the air exhaust hole is less likely to be drawn immediately from the air inlet, whereby decrease of cooling efficiency of the battery can be prevented. Thus, according to the present invention, an adverse effect caused by exhaust of heated cooling air can be suppressed.

Further, it is preferable that the air exhaust hole be formed at a location higher than the location of the air inlet. According to the battery cooling structure thus configured, the high temperature air exhausted from the air exhaust hole is less likely to travel toward the air inlet, thus achieving further effective suppression of decrease of cooling efficiency of the battery.

Further, it is preferable that the air inlet and the air exhaust hole be positioned opposite to each other with respect to a center line in a vehicular width direction of the vehicle. According to the battery cooling structure thus configured, the air inlet and the air exhaust hole are positioned away from each other in the vehicular width direction. Accordingly, the air exhausted from the air exhaust hole is less likely to be drawn via the air inlet.

Further, it is preferable that the air intake duct include a first portion and a second portion divided by the luggage room and connected to each other. According to the battery cooling structure thus configured, with the first portion and the second portion separated, the battery can be installed in the luggage room to improve workability upon installing the battery.

Further, it is preferable that the battery cooling structure further includes: a fan for distributing the cooling air to the air intake duct; and a frame member, provided in the luggage room, for reinforcing a body of the vehicle. The fan is fixed to the frame member. According to the battery cooling structure thus configured, with the fan fixed to a highly rigid frame member, the vibration of the fan can be prevented from being transferred to the vehicular main body.

As described above, according to the present invention, a battery cooling structure suppressing an adverse effect caused by exhaust of heated cooling air can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described with reference to figures. It should be noted that the same or equivalent members are given the same reference characters in the figures referenced below.

FIG. 1is a perspective view showing a hybrid car to which a battery cooling structure of an embodiment of the present invention is applied. InFIG. 1, surroundings of a luggage room of the hybrid car are shown but its rear seat is not illustrated therein.FIG. 2is a cross sectional view of the hybrid car ofFIG. 1.

Referring toFIG. 1andFIG. 2, the hybrid car, serving as a vehicle, employs an internal combustion engine such as a gasoline engine or a diesel engine and a vehicle driving motor as motive power sources.

In the hybrid car, a vehicular cabin42and a luggage room44are formed. Vehicular cabin42is a space in which an occupant resides. Vehicular cabin42is provided with a rear seat50. Rear seat50is positioned on a floor49that is a bottom portion of the vehicle. Rear seat50includes a base portion51on which an occupant sits, and a backrest portion52on which the occupant leans with his/her back. Luggage room44is a space for mainly loading a luggage therein. Luggage room44is formed in a rear portion of the vehicle.

Vehicular cabin42and luggage room44are sectioned by a partition panel31and an upper back panel45. Partition panel31is positioned adjacent to rear seat50. Partition panel31stands on floor49. Between partition panel31and rear seat50, a clearance32is formed. Between partition panel31and backrest portion52, clearance32is formed. Clearance32extends in a flat plane behind backrest portion52. Partition panel31is positioned in the forward side of the vehicle relative to luggage room44. Partition panel31extends in a plate-like manner in the vehicular width direction.

Partition panel31is formed from a metal plate. Partition panel31blocks heat and noise between vehicular cabin42and luggage room44and increases rigidity of the vehicular body to improve driving stability of the vehicle.

Upper back panel45extends in generally the horizontal direction. Upper back panel45is positioned in luggage room44at the upper side in the vertical direction. Upper back panel45is provided with an air vent hole46. Air vent hole46communicates between vehicular cabin42and luggage room44. Via air vent hole46, air in vehicular cabin42is exhausted from a vent grille63.

The hybrid car includes a battery21. Battery21is contained in luggage room44. Battery21is used for traveling of the hybrid car. Battery21supplies electric power to the vehicle driving motor installed in the hybrid car. Battery21is not particularly limited as long as it is a chargeable/dischargeable secondary battery. For example, battery21may be a nickel hydrogen battery or a lithium ion battery.

In the hybrid car in the present embodiment, when driving the vehicle driving motor, direct current discharged from battery21is converted by an inverter into alternating current, which is then supplied to the motor. When the motor is functioned as a generator to perform energy regeneration, alternating current generated by the motor is converted by the inverter into direct current, which then charges battery21.

The hybrid car includes an air intake duct23. Air intake duct23extends between vehicular cabin42and battery21provided in luggage room44. Air intake duct23passes through partition panel31. Air intake duct23runs within luggage room44. Air intake duct23runs under rear seat50. Air intake duct23runs in a clearance between base portion51and floor49. Air intake duct23extends in the front-back direction of the vehicle.

Air intake duct23includes an air inlet24. Air inlet24is open in vehicular cabin42. Air inlet24is open in a space at the foot of rear seat50. The space at the foot of rear seat50is less likely to be affected by direct sunlight and therefore has a low temperature in general. Hence, such low temperature air can be introduced to battery21as cooling air.

In partition panel31, a duct hole36is formed. Duct hole36is formed in partition panel31at its one end in the vehicular width direction. Duct hole36is formed at a lower end of partition panel31. Partition panel31includes a panel portion31p. Panel portion31pis detachably attachable to partition panel31. Duct hole36is formed in panel portion31p.

The hybrid car includes an air exhaust duct25. Air exhaust duct25extends between battery21and a space between a trim (interior) of luggage room44and the body. Air exhaust duct25is arranged in luggage room44. Air exhaust duct25includes air outlets61and62. Air outlet61is open in luggage room44. Air outlet62is open in the space between the trim of luggage room44and the body.

The hybrid car includes a fan26. Fan26distributes cooling air to air intake duct23and air exhaust duct25in order to cool battery21. Fan26is positioned on a path of air exhaust duct25. Fan26is positioned in luggage room44. Fan26is an electrically driven sirocco fan that draws air from the central portion of the rotary fan in the rotation axis direction and exhausts the cooling air radially with respect to the rotation axis. Fan26is a pull-in type fan that draws cooling air from battery21.

It should be noted that fan26is not limited to the sirocco fan but may be, for example, a cross flow fan or a propeller fan. Fan26may be a push type fan for supplying cooling air to battery21.

When fan26is driven, air in vehicular cabin42is drawn into air intake duct23via air inlet24. The air passes through air intake duct23and is then introduced to battery21as cooling air. The cooling air cools battery21, is heated accordingly, and passes through air exhaust duct25. A part of the air is exhausted to luggage room44via air outlet61, and the rest thereof is exhausted to outside the car via air outlet62and vent grille63.

In partition panel31, an air exhaust hole37is formed. Air exhaust hole37communicates between vehicular cabin42and luggage room44. Air exhaust hole37is formed on the other end of partition panel31in the vehicular width direction. Air exhaust hole37is formed at a lower end of partition panel31. Air exhaust hole37is positioned away from duct hole36. Air exhaust hole37and duct hole36are formed away from each other in the vehicular width direction. Air exhaust hole37is formed away from air inlet24. Relative to the center line of the hybrid car in the vehicular width direction, air inlet24is located at one side and air exhaust hole37is located at the other side. Air exhaust hole37has an opening area larger than that of air vent hole46.

The temperature of air in luggage room44is increased by the high temperature cooling air exhausted via air outlet61and influence of heat generated by battery21. Meanwhile, when air in vehicular cabin42continues to be drawn via air inlet24, the internal pressure in vehicular cabin42is decreased, resulting in an adverse effect over air conditioning or the like. Hence, in the present embodiment, the air in luggage room44is brought back to vehicular cabin42via air exhaust hole37.

On this occasion, air exhaust hole37formed in partition panel31allows air exhausted from air exhaust hole37to first flow into clearance32between rear seat50and partition panel31. The air flows in clearance32, and is let out to vehicular cabin42from between rear seat50and interior components (a trim, a carpet, and the like). Such a process allows the air in luggage room44to be dispersed and brought back to vehicular cabin42, which can prevent the high temperature airflow from making an occupant of vehicular cabin42feel unpleasant. Further, mainly via air exhaust hole37, the air is exhausted from luggage room44to vehicular cabin42. This can prevent the air in luggage room44from flowing thereinto via air vent hole46that is substantially as high as the head of an occupant sitting on rear seat50.

Further, air exhaust hole37is formed at a location spaced away from duct hole36and higher than the location of air inlet24. By arranging them in this way, a configuration in which air exhaust hole37and air inlet24are positioned distant away from each other can be readily obtained. Further, the high temperature air exhausted from air exhaust hole37is less likely to travel from high to low. For these reasons, according to the present embodiment, air exhausted from air exhaust hole37can be effectively prevented from being reintroduced to battery21via air inlet24.

The battery cooling structure of the embodiment of the present invention includes: battery21provided in luggage room44of the hybrid car serving as a vehicle; air intake-duct23, including air inlet24open in vehicular cabin42, for supplying air in vehicular cabin42to battery21as cooling air; and partition panel31standing away from rear seat50with clearance32therebetween to section luggage room44and vehicular cabin42and provided with duct hole36to which air intake duct23is inserted. Partition panel31is provided with air exhaust hole37for exhausting air in luggage room44to vehicular cabin42. Air exhaust hole37is formed at a location spaced away from duct hole36.

According to the battery cooling structure thus configured in the embodiment of the present invention, even though high temperature air is exhausted from luggage room44to vehicular cabin42, pleasantness in vehicular cabin42can be maintained. Further, since the air exhausted from luggage room44is prevented from being drawn immediately to air intake duct23, cooling efficiency of battery21can be improved.

Now, the cooling structure of the hybrid car ofFIG. 1andFIG. 2will be described more in detail. Referring toFIG. 2, the hybrid car includes a deck board47. Deck board47is provided in luggage room44. Deck board47extends in generally the horizontal direction. On deck board47, a luggage is placed. Below deck board47, air intake duct23, air exhaust duct25, and fan26are provided.

In the present embodiment, based on the ground level, the maximal heights of air intake duct23, air exhaust duct25, and fan26are equal to or lower than the maximal height of battery21. With such a configuration, no component protrudes higher than the height of battery21, so a large capacity can be secured in luggage room44.

FIG. 3is a plan view showing a mounted structure of the fan inFIG. 1.FIG. 4is a cross sectional view of the hybrid car taken along a line IV-IV inFIG. 3. Referring toFIG. 3andFIG. 4, the hybrid car includes side members56. Side members56are provided on floor49. Side members56extend in the front-back direction of the vehicle. Side members56are provided in the opposing ends of floor49in the vehicular width direction respectively. Each of side members56is a frame member for reinforcing the body of the hybrid car. Side member56is a frame member for reinforcing floor49.

In the present embodiment, fan26is fixed to side member56. Fan26is fastened to side member56by bolts58. Since side member56is highly rigid, such a configuration can suppress transfer of vibration from fan26to the vehicular main body. This achieves improved NV (noise and vibration) property of the hybrid car. Also, a vibration isolating elastic body interposed between fan26and the vehicular main body can be omitted, thus allowing for cost reduction.

FIG. 5is an exploded view of the partition panel inFIG. 1. Referring toFIG. 2andFIG. 5, in the present embodiment, air intake duct23includes a duct portion23mand a duct portion23n. Duct portion23mand duct portion23nare divided by luggage room44but are jointed to each other. Duct portion23mincludes air inlet24. When duct portion23mis inserted into duct hole36, duct portion23mis in one piece with panel portion31p. Duct portion23nis connected to battery21.

With such a configuration, in a step of assembling battery21, battery21to which only duct portion23nis connected is installed in luggage room44, and thereafter duct portion23nand duct portion23mare connected. In other words, in the present embodiment, a step of installing battery21and a step of inserting duct23into partition panel31can be performed separately. This allows improved workability upon the assembling of battery21.

FIG. 6is a perspective view showing a variation of the air intake duct inFIG. 5. Referring toFIG. 6, in this variation, panel portion31pand duct portion23mare provided as separate members. To secure air-tightness between luggage room44and vehicular cabin42, a sealing member39is inserted in a clearance between the circumferential edge of duct hole36and duct portion23m. In such a configuration, the aforementioned advantage can be obtained as well.

It should be noted that the present invention is applicable to a fuel battery hybrid vehicle (FCHV: Fuel Cell Hybrid Vehicle) employing a fuel battery and a battery as motive power sources or to an electric vehicle (EV). In the hybrid car in the present embodiment, the internal combustion engine is driven at a fuel consumption optimum operation point, whereas in the fuel battery hybrid vehicle, the fuel battery is driven at a power generation optimum operation point. Note also that both the hybrid vehicles are basically the same in terms of use of batteries.

The embodiment disclosed herein is illustrative and non-restrictive in any respect. The scope of the present invention is defined by the scope of claims rather than the above description, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

INDUSTRIAL APPLICABILITY

The present invention is mainly used for a hybrid vehicle employing an internal combustion engine and a vehicle driving motor as motive power sources, a fuel battery hybrid vehicle employing a fuel battery and a battery as motive power sources, an electric vehicle, and the like.