Battery cooling structure

Abstract

Battery cooling structure for cooling a battery mounted in a vehicle, wherein the battery cooling structure comprises the following: a battery pack (20) in which the battery is housed in an interior space, wherein the battery pack (20) is arranged under a rear seat (10) of the vehicle; an air supply device (26) configured to send cooling air to the battery pack (20); and an air outlet device configured to discharge exhaust air from the battery pack (20), wherein the air outlet device has a vent opening (54) that discharges the exhaust air, characterized in that the vent opening (54) is provided in a floor surface in a rear space behind the rear seat (10) in the vehicle, and wherein the vent opening (54) is configured to discharge the exhaust air from the battery pack (20) upwards from the vent opening (54) into the rear space.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The invention relates to a battery cooling structure for cooling a battery mounted in a vehicle. 2. Description of the background technology

[0002] Vehicles such as hybrid vehicles (HV) and electric vehicles (EV) travel by driving a motor using electric power from a battery. Therefore, a battery is mounted in the vehicle to ensure the required electric power. Furthermore, Japanese Patent Application Laid-Open No. 2010-036723 (JP 2010-036723 A) proposes locating the battery under a rear seat to improve battery mounting space efficiency. Furthermore, a battery generates heat during charging and discharging. In particular, a battery for a vehicle frequently flows a large current, so the amount of heat generated is large. If the battery temperature becomes high, the battery deteriorates, so it is necessary to provide a structure for cooling the battery.JP 2010-036723 A describes a structure that draws air into a vehicle interior from in front of a lower portion of the rear seat and discharges this air from behind a lower portion of the rear seat out of the vehicle.

[0003] Furthermore, a battery cooling structure according to the preamble of claim 1 is known from WO 2013 / 084 935 A1. Further battery cooling structures are disclosed in EP 2 368 740 A1 and JP 2002-134 084 A. SUMMARY OF THE INVENTION

[0004] If the exhaust air that has cooled the battery under the rear seat is discharged from the vehicle as it is, the exhaust passage can be short, which is advantageous in terms of space, and the pressure loss is low, making it efficient. However, in this configuration, the vent is located at a relatively low position, so sufficient consideration must be given to preventing foreign matter, water, etc., from the road surface from entering the battery pack.

[0005] Therefore, one aspect of the invention relates to a battery cooling structure for cooling a battery mounted in a vehicle. This battery cooling structure includes a battery pack, an air supply device, and an air discharge device. The battery pack accommodates the battery in an interior space and is arranged under a rear seat of the vehicle. The air supply device is configured to send cooling air to the battery pack. The air discharge device is configured to discharge exhaust air from the battery pack. A vent that discharges the exhaust air is provided in a floor surface in a rear space behind the rear seat in the vehicle. The vent is configured to discharge the exhaust air from the battery pack upward into the rear space from the vent.

[0006] Furthermore, in the battery cooling structure described above, the rear compartment may be a trunk of the vehicle, and a spare tire storage compartment may be provided in a lower portion of the trunk. Furthermore, the vent opening may be positioned in front of the spare tire storage compartment.

[0007] Furthermore, in the battery cooling structure described above, the air discharge device may have an exhaust duct extending from the battery pack to the rear space, and a discharge port of the exhaust duct may be provided below the floor surface and open into a discharge channel extending in a vehicle width direction. The discharge duct may have a discharge port at a position planarly offset with respect to the discharge port on a front surface side of the discharge duct. After the exhaust air discharged from the discharge port of the exhaust duct flows through the discharge duct in a direction parallel to the floor surface in the vehicle width direction, the exhaust air may be discharged upward into the rear space via the discharge port and the vent port.

[0008] Furthermore, in the battery cooling structure described above, the discharge opening of the exhaust duct may be covered with fabric. Furthermore, in the battery cooling structure described above, the discharge opening of the exhaust duct may be covered with a grille. Furthermore, in the battery cooling structure described above, the discharge opening of the exhaust duct may be provided in a direction with a recess in front of the exhaust opening with respect to a vehicle longitudinal direction, and a closed portion may be provided in front of the exhaust opening with respect to the vehicle longitudinal direction.

[0009] This type of battery cooling structure makes it possible to effectively prevent the intrusion of foreign substances and the like through the vent hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Features, advantages, and technical and industrial significance of exemplary embodiments of the invention are described below with reference to the accompanying drawings, in which like reference numerals designate like elements, and in which: Fig. 1A and Fig. 1B are views showing the flow of supply air and exhaust air to and from a battery pack according to a battery cooling structure of an exemplary embodiment of the invention; Fig. 2 is a view of the exterior of the battery pack and a channel according to the battery cooling structure of the exemplary embodiment; Fig. 3A, Fig. 3B and Fig. 3C are views of the structure of an exhaust duct behind a rear seat according to the battery cooling structure of an exemplary embodiment; and Fig. 4A, Fig. 4B and Fig. 4C shows views of the outside of the exhaust air duct, a supply air duct, a fan, and an intake air duct according to the battery cooling structure of the exemplary embodiment. DETAILED DESCRIPTION OF EMBODIMENTS

[0011] Exemplary embodiments of the invention will be described below with reference to the accompanying drawings. The invention is not limited to the exemplary embodiments described here.

[0012] First, the structure related to the supply air and the exhaust air in a battery cooling structure of this exemplary embodiment will be described. Fig. 1A and Fig. 1B are views of the structures related to the flow of supply air and exhaust air to and from a battery pack in this exemplary embodiment.

[0013] A rear seat 10 includes a seat cushion 10a, a backrest 10b, and a battery housing space 10c below the seat cushion 10a. The front and sides of the battery housing space 10c are surrounded by a lower panel 12. Furthermore, a vehicle body 14 is positioned on a floor surface side of the battery housing space 10c.

[0014] A battery pack 20 is arranged inside the battery receiving space 10c, and a battery stack 22 is arranged inside this battery pack 20. This battery stack 22 is formed by a plurality of battery modules 24 connected in series.

[0015] The inside of the battery pack 20 is sealed by a lower housing and a top cover. An air supply flow path is formed above the battery stack 22, and an exhaust flow path is formed below the battery stack 22.

[0016] An air supply duct 26 is connected to a rear side of the air supply flow path above the battery stack 22 inside the battery pack 20, as shown in Fig. 1A, and this supply air duct 26 extends rearwardly and is connected to a fan side of a fan 28.

[0017] An exhaust duct 30 is connected to a rear side of the exhaust flow path below the battery stack 22 of the battery pack 20, as shown in Fig. 1B, and this exhaust duct 30 extends rearwardly with an exhaust opening 32 opening upwardly.

[0018] A rear space (rear space) of the backrest 10b of the rear seat 10 serves as a trunk space 40. A floor surface of the trunk space 40 is formed by a deck board 42. This deck board 42 is positioned in the trunk space 40 so that it can be lifted and removed. A spare tire compartment 44, in which a spare tire is accommodated, is provided under the deck board 42, and a spare tire is accommodated therein. Furthermore, an accessory compartment such as a shelf is provided under the deck board 42 at a front upper portion in the spare tire compartment 44.

[0019] In addition, the previously described blower 28 is arranged behind the rear seat 10 and in front of the spare tire compartment 44. That is, there is a space under the trunk 40 behind the rear seat 10 and in front of the spare tire compartment 44, and the blower 28 is arranged here. An intake air duct 60 (see Fig. 2) and the supply air duct 26 are connected to this blower 28. Furthermore, a rear portion of the exhaust air duct 30 and an exhaust port 32 are provided. A discharge duct 48 extending in a vehicle width direction is provided at an upper portion of this exhaust port 32, and a discharge port panel 50 is provided on a front surface of this discharge duct 48. This discharge port panel 50 has a closed portion and an open portion. The open portion is an exhaust port. A vent port 54 formed through a gap between a front end of the deck board 42 and a rear surface of the seat back 10b via this exhaust port is open to the trunk 40. A seat member 52 is provided between a lower front end of the discharge duct 48 and the rear surface of the seat back 10b so that objects do not fall off.

[0020] Here is Fig. 2 shows a perspective view of the battery pack 20 and a duct. In this case, the intake air duct 60 is connected to the inlet side of the blower 28. This intake air duct 60 draws air from an inlet 62 in a side surface on the door side of the lower trim of the rear seat 10. In Fig. 2, the seat cushion 10a and the lower cover 12 and the like, which are shown in Fig. 1A and Fig. 1B, however, the inlet 62 is open to the door-side surface of the lower trim panel 12. A cloth or a grate or the like is placed over the front surface of the inlet 62 to prevent foreign matter from entering from the outside.

[0021] In this way, the intake air duct 60, the supply air duct 26 and the exhaust air duct 30 are arranged in the order from the door side to the inside in the space below the seat cushion 10a of the rear seat 10.

[0022] Next, the structure at the rear of the battery cooling structure of this exemplary embodiment will be described. Fig. 3A, Fig. 3B and Fig. 3C are views of the structure of a section where the exhaust air opening 32 opens to the outside. Fig. 3A shows the top of the drawing facing the rear of the vehicle and the side of the drawing facing the vehicle width direction. In Fig. 3B shows the top of the drawing facing upwards with respect to the vehicle, and the side of the drawing facing in the vehicle width direction. Fig. 3C shows the top of the drawing with respect to the vehicle upwards, the left side of the drawing points to the front of the vehicle, and the right side of the drawing points to the rear of the vehicle.

[0023] In this way, the exhaust port 32 is provided in front of an accessory compartment 46 and is open to a bottom surface of the discharge duct 48 extending in the width direction of the vehicle. This discharge duct 48 has the discharge port panel 50 at the front. This discharge port panel 50 has a discharge port 50a covered by cloth or a grate or the like, and has a closed portion 50b. The discharge port 50a is provided somewhere other than (i.e., at a location except) the front of the exhaust port 32. The front of the exhaust port 32 is the closed portion 50b. The discharge port panel 50 may be formed by a panel in which the discharge port 50a is formed as an opening, or the closed portion 50b may be arranged at appropriate intervals to form an open portion (i.e., the discharge port 50a) therebetween.

[0024] Therefore, the exhaust air, after being temporarily curved in the width direction of the vehicle by the exhaust port 32, then flows forward toward the rear surface of the backrest 10b of the rear seat 10. The exhaust air then passes through the vent port 54, which is the gap between the front end of the deck board 42 and the rear surface of the rear seat 10b, and is then discharged upward into the trunk 40.

[0025] A cloth or a grate may also be arranged on the upper surface of the exhaust port 32 to prevent objects from falling into the exhaust port 32. Furthermore, the discharge port panel 50 may preferably be removed from the discharge duct 48. Furthermore, the upper end of the exhaust port 32 is flange-shaped and positioned above the bottom surface of the discharge duct 48. By extending this portion upward in a tubular shape, water and the like will not reach the exhaust port 32 even if they enter the discharge duct 48.

[0026] Next, the airflow in the battery cooling structure of this exemplary embodiment will be described. Air inside the vehicle cabin is sucked in from the inlet 62 by driving the blower 28. This air is sucked into the blower 28 via the intake air duct 60. Air discharged from the blower 28 is supplied to an upper space (i.e., an intake air flow path) in the battery pack 20 via the intake air duct 26. The battery stack 22 is arranged inside the battery pack 20, but since a gap exists between the battery modules 24 of the battery stack 22, the air flows downward through this gap, so that the battery modules 24 are effectively cooled. At this time, cooling air can be passed through this gap between the stacked battery modules 24 by closing the area between the periphery of the battery stacks 22 and a peripheral inner wall of the battery pack 20.

[0027] Exhaust air is discharged from a lower space (i.e., an exhaust air flow path) in the battery pack 20 into the trunk 40 through the exhaust duct 30, the exhaust port 32, the discharge duct 48, the discharge port panel 50, and the vent port 54, which is the gap between the front end of the deck board 42 and the rear surface of the rear seat 10b. In this example, the vent port 54 is positioned along almost the entire width in the width direction of the vehicle, but it may be limited to only a specific portion.

[0028] Next, the individual structures of the battery cooling structure of this exemplary embodiment will be described. Fig. 1A and Fig. 1B, only one rear seat 10 is shown, but normally there are two rear seats 10, and battery packs 20 and a mechanism for cooling the battery packs 20 are arranged under the rear seats 10 in the same configuration as shown in Fig. 1A and Fig. 1B is shown.

[0029] These include Fig. 4A, Fig. 4B and Fig. 4C Views of the outside of the exhaust air duct 30, the supply air duct 26 and the inlet air duct 60, respectively. As in Fig. As shown in Fig. 4A, the exhaust duct 30 extends rearward from a rear end of a lower case constituting a bottom surface of the battery pack 20. As shown in the drawing, a front end of the exhaust duct 30 is a flat opening that is narrow in the vertical direction (i.e., narrow in the vehicle height direction) and wide in the vehicle width direction. Air from the entire discharge flow path under the battery stack 22 is discharged from this opening. The width of the exhaust duct 30 gradually narrows toward the exhaust opening 32, and the exhaust opening 32 has a substantially square opening.

[0030] Furthermore, a periphery of an open portion 30a of the front end of the exhaust duct 30 is reinforced by a flange portion 30b. This open portion 30a can be connected to the discharge flow path in an airtight manner by placing the lower side of the flange portion 30b tightly against the lower case and holding the upper side of the flange portion 30b downward against the rear end portion of the battery pack 22. A side portion of the flange portion 30b is connected in an airtight manner to an inner side wall of an upper cover covering a side portion and an upper portion of the battery pack 20. An airtight cover is achieved by disposing a sealant around the flange portion 30b.

[0031] A more reliable seal is achieved by using a recessed section that is recessed downwards in two places, as in Fig. 4A, is provided at an upper edge portion of the flange portion 30b, and the shape of a lower surface of the rear end of the battery stack 22 is adjusted accordingly. Furthermore, sufficient strength is imparted to the flange portion 30b by bringing the recessed portion directly into contact with the lower edge portion of the flange portion 30b.

[0032] The front end of the intake air duct 26 is a flat open portion 26a which is narrow in the vertical direction and wide in the width direction, which matches the shape of the upper space (ie, the intake air flow path) of the battery pack 20, as shown in Fig. 4B. Further, a flange portion 26b is formed around the open portion 26a, and the periphery of this flange portion 26b is sealed via a sealant between the rear upper end portion of the battery stack 22 and the top cover of the battery pack 20. The intake air duct 26 extends rearward while gradually narrowing in width. This intake air duct 26 is connected to an air outlet 28a around the blower 28. The blower 28 has a cylindrical shape and blows out air sucked in from a side inlet port 28b in a radial direction and blows out the air from the air outlet 28a provided in a portion of a doughnut-shaped blower chamber.

[0033] The intake air duct 60 has a tubular shape extending from front to rear, and the rear end of the intake air duct 60 is connected to the inlet port 28b of the blower 28, as shown in Fig.4C. The front end is a rectangular inlet 62.

[0034] Next, the effects of the exemplary embodiment will be described. Thus, in this exemplary embodiment, the battery pack 20 is accommodated in the battery accommodation space 10c under the seat cushion 10a of the rear seat 10, so that the battery does not interfere with other equipment, and the vehicle space can be used more efficiently. Furthermore, the discharge opening 50a of the discharge duct 48 is provided right behind the rear surface of the lower portion of the seatback 10b of the rear seat 10, so that the discharge duct 48 can be relatively short, thereby enabling pressure loss to be small.

[0035] Furthermore, the exhaust port 32 opens into the discharge duct 48, the discharge duct 48 discharges the exhaust air from the discharge port 50a, and the discharge port 50a is directed in a substantially horizontal direction and is covered with cloth or the like, so that foreign matter can be prevented from entering from the outside. Specifically, the discharge port 50a of the exhaust port 32 is offset in the width direction, so that air discharged upward from the exhaust port 32 temporarily moves in the width direction of the vehicle and then impacts against the rear surface of the seatback 10b from the discharge port 50a in the front surface and escapes upward. This type of air path makes it possible to reliably prevent foreign matter from entering and the like. In addition, the discharge port 50a is provided over a relatively large area in the vehicle width direction, so that the pressure loss can be reduced with a relatively complex path.

[0036] Exhaust air is discharged from the opening between the deck board 42 and the rear surface of the seatback 10b into the trunk 40. Therefore, this airflow is unlikely to affect an occupant, so that the exhaust air does not cause any discomfort to the occupant.

[0037] In addition, the inlet 62 is located at a lower side portion of the rear seat, so the intake airflow from there is less likely to be felt by a passenger's leg or the like. Furthermore, the inlet 62 is oriented at an angle, so the intake airflow is not as fast. As a result, the intake air is not easily felt by a passenger, and noise generated by the intake air can also be suppressed.

Claims

[1] A battery cooling structure for cooling a battery mounted in a vehicle, the battery cooling structure comprising: a battery pack (20) in which the battery is accommodated in an interior space, the battery pack (20) being arranged under a rear seat (10) of the vehicle; an air supply device (26) configured to send cooling air to the battery pack (20); and an air outlet device configured to discharge exhaust air from the battery pack (20), the air outlet device having a vent opening (54) that discharges the exhaust air, characterized by that the vent opening (54) is provided in a floor surface in a rear space behind the rear seat (10) in the vehicle, and wherein the vent opening (54) is configured to discharge the exhaust air from the battery pack (20) upwardly from the vent opening (54) into the rear space. [2] Battery cooling structure according to claim 1, characterized by , that the rear space is a trunk (40) of the vehicle and a spare tire storage space is provided in a lower portion of the trunk; and the vent opening (54) is positioned in front of the spare tire compartment. [3] Battery cooling structure according to claim 1 or 2, characterized by , that the air outlet device has an exhaust duct (30) extending from the battery pack (20) to the rear space, and an outlet opening (32) of the exhaust duct (30) is provided below the floor surface and opens into a discharge duct (48) extending in a vehicle width direction; the discharge duct (48) has a discharge opening (50a) in a planar offset position with respect to the exhaust air opening (32) on a front surface side of the discharge duct (48); and after the exhaust air discharged from the outlet opening (32) of the exhaust air duct (30) flows through the discharge duct (48) in a direction parallel to the floor surface in the vehicle width direction, the exhaust air is discharged upward into the rear space via the discharge opening (50a) and the vent opening (54). [4] Battery cooling structure according to claim 3, characterized by that the discharge opening (50a) of the exhaust air duct (30) is covered by a fabric. [5] Battery cooling structure according to claim 3, characterized by that the discharge opening (50a) of the exhaust air duct (30) is covered by a grille. [6] Battery cooling structure according to claim 3, characterized by that the discharge opening (50a) of the exhaust air duct (30) is provided in a direction from which, with respect to a vehicle longitudinal direction, in front of the outlet opening (32) is excluded, and a closed portion (50b) is provided in front of the outlet opening (32) with respect to the vehicle longitudinal direction.

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