JP2011116321A - Cooling structure of battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure of a battery pack capable of uniformizing the temperature of each battery stored in a battery case. <P>SOLUTION: This cooling structure includes an air blowing passage 100 which has at least a main air blowing passage 101 provided along a longitudinal direction of the battery case 50 in a short direction center part of the battery case 50, and through which cooling air passes. The cooling air supplied from a cooling unit 60 is circulated in a vertical direction in the battery case 50 via the air blowing passage 100 and returns to a cooling unit 60, to suppress a variation of the temperatures of the plurality of batteries 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cooling structure for a battery pack containing a battery, and more particularly to a cooling structure for a battery pack mounted on an electric vehicle such as an electric vehicle or a hybrid vehicle.

  For example, a battery pack mounted on an electric vehicle such as an electric vehicle or a hybrid vehicle includes a battery having a plurality of battery cells and a battery case in which the battery is accommodated. The electric vehicle is configured to travel by driving a drive motor with electric power supplied from a battery.

  For example, when electric power is consumed or charged by running an electric vehicle, the temperature of the battery rises. For this reason, the battery pack usually requires a cooling structure for cooling the battery. Various battery pack cooling structures have been proposed. For example, there is a battery case in which a battery case is partitioned into left and right regions by a holder, which is a partition member, and a cooling air flow path including a forward path and a return path is formed in the battery case (for example, see Patent Document 1).

JP 2006-318820 A

  However, in the structure in which the cooling air flow path is formed by partitioning the battery case in this way, the temperature of the cooling air flowing through the cooling air flow path gradually increases, and on the upstream side and the downstream side of the cooling air flow path, A temperature difference of the cooling air will occur. Along with this, there is a problem that a temperature difference occurs between the battery located on the upstream side of the cooling air flow path and the battery located on the downstream side.

  In order to solve this problem, Patent Document 1 discloses a structure provided with a bypass hole that connects the forward path and the return path of the cooling air flow path. Thereby, although the temperature variation of a battery can be suppressed, further equalization of the temperature of each battery is desired.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a battery pack cooling structure capable of making the temperature of each battery accommodated in a battery case uniform.

  A first aspect of the present invention that solves the above-described problems includes a battery, a battery case that includes a battery tray and a battery cover, and stores the battery, and is provided on one end side in the longitudinal direction of the battery case. A battery pack cooling structure comprising a cooling unit for supplying cooling air into the battery case, wherein at least a main air passage provided along the longitudinal direction of the battery case at the center in the short direction of the battery case A cooling passage through which the cooling air passes, and the cooling air supplied from the cooling unit circulates up and down in the battery case through the ventilation passage and returns to the cooling unit. The battery pack cooling structure is characterized in that:

  In the first aspect, since the battery is cooled when the cooling air flows in one direction in the battery case and circulates in the battery case, the temperature rise of the cooling air is suppressed, and each battery is effectively and substantially uniform. To be cooled.

  In a second aspect of the present invention, the air passage includes a distribution passage that is connected to an end portion of the main air passage and distributes the cooling air in a direction intersecting the main air passage. The battery pack cooling structure according to the first aspect.

  In the second aspect, the cooling air is distributed over the short direction of the battery case by distributing the cooling air through the distribution path. Therefore, each battery is cooled more evenly.

  According to a third aspect of the present invention, there is provided the battery pack cooling structure according to the first or second aspect, wherein the air passage is formed by a projecting portion projecting the battery cover upward.

  In the third aspect, it is possible to relatively easily form the air passage that allows the cooling air to flow well from one end side in the longitudinal direction to the other end side in the battery case. Further, since the thickness of the portion other than the protruding portion of the battery case becomes relatively thin, the vehicle interior space can be widened by arranging the protruding portion under the backbone of the vehicle floor.

  According to a fourth aspect of the present invention, there is provided the battery pack according to the third aspect, wherein the air passage is formed by an air duct arranged in the projecting portion and having one end connected to the cooling unit. It is in the cooling structure.

  In this 4th aspect, since a ventilation path is formed with the ventilation duct, a cooling wind can be flowed still more favorably from the longitudinal direction one end side in a battery case to the other end side.

  According to a fifth aspect of the present invention, in the battery pack according to the fourth aspect, a lower opening for flowing the cooling air downward is provided near the other end of the air duct. It is in the cooling structure.

  In the fifth aspect, by directing the flow of the cooling air through the lower opening, the cooling air circulates more reliably and satisfactorily in the battery case, thereby further cooling each battery.

  According to a sixth aspect of the present invention, there is provided a first to a fifth aspect of the present invention, comprising a guide member that is provided on the inner side of the lower opening of the battery case and that guides cooling air flowing out from the lower opening downward. The battery pack cooling structure according to any one of the embodiments.

  In the sixth aspect, by directing the flow of the cooling air by the guide member, the cooling air circulates more reliably and satisfactorily through the space in which the battery is disposed in the battery case, thereby further cooling each battery. .

  According to a seventh aspect of the present invention, each battery includes a plurality of battery cells arranged in parallel at a predetermined interval, and the main air passage extends in a direction perpendicular to the direction in which the battery cells are arranged. The battery pack cooling structure according to any one of the first to sixth aspects is characterized by the above.

  In the seventh aspect, since the cooling air surely flows between the battery cells, each battery is cooled more satisfactorily.

  According to the cooling structure of the battery pack of the present invention, a plurality of batteries housed in the battery case can be cooled substantially uniformly. That is, it is possible to suppress a temperature difference between the batteries.

It is a disassembled perspective view of the battery pack which concerns on one Embodiment of this invention. It is a top view of the battery pack which concerns on one Embodiment of this invention. It is AA 'sectional drawing of the battery pack concerning one Embodiment of this invention. It is BB 'sectional drawing of the battery pack concerning one Embodiment of this invention. It is a figure explaining an example of the flow of the cooling air in a battery pack. It is a figure explaining the other example of the flow of the cooling air in a battery pack.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an exploded perspective view of the battery pack according to the present embodiment, and FIG. 2 is a plan view thereof. 3 is a cross-sectional view taken along the line AA ′ of FIG. 2, and FIG. 4 is a cross-sectional view taken along the line BB ′ of FIG.

  The battery pack of the present invention is mounted on, for example, an electric vehicle and supplies electric power to a traveling motor of the electric vehicle. Although not shown, the battery pack is fixed below the floor of the vehicle body. As shown in FIGS. 1 to 4, the battery pack 10 includes a plurality of batteries 20, a battery tray 30 and a battery cover 40, and a battery case 50 in which the batteries 20 are housed, and a cooling in the battery case 50. And a cooling unit 60 for supplying wind.

  Each battery 20 includes a plurality of battery cells 21 arranged in parallel. For example, in the present embodiment, two types of batteries 20, a first battery 20 </ b> A configured by eight battery cells 21 and a second battery 20 </ b> B configured by four battery cells 21, are battery cases. 50. Although not shown, the plurality of battery cells 21 are integrated by a battery holder to constitute the battery 20. Of course, these battery cells 21 do not necessarily have to be integrated by the battery holder.

  The battery case 50 is a container that accommodates the plurality of batteries 20. The battery tray 30 constitutes the lower part of the battery case 50, and the battery cover 40 constitutes the upper part of the battery case 50. That is, the plurality of batteries 20 are accommodated in a space formed by the battery tray 30 and the battery cover 40.

  In the present embodiment, the first battery 20A and the second battery 20B are arranged one by one in the short direction (vertical direction in FIG. 2) of the battery case 50, and the longitudinal direction of the battery case 50 (FIG. 2). In the middle left and right direction), seven first batteries 20A and seven second batteries 20B are arranged in parallel. As shown in FIG. 3, in this embodiment, the five batteries 20 on the front side (left side in FIG. 2) of the battery case 50 are placed on the battery tray 30 with the terminal portions 22 facing upward. The two batteries 20 on the rear side of the case 50 are placed so that the terminal portion 22 faces the front or rear of the battery tray 30. For this reason, the height (depth) of the battery cover 40 corresponding to the two batteries 20 on the rear side of the battery case 50 is higher than the other parts.

  In the battery tray 30, ribs 31 are erected at portions corresponding to the spaces between the batteries 20. The ribs 31 serve to increase the rigidity of the battery tray 30 while partitioning the area where each battery 20 is accommodated. Although not shown, a seal member is provided between the battery tray 30 and the battery cover 40, and the seal member is configured to prevent water or the like from entering the battery case 50.

  A space S in which the battery 20 is not disposed is provided on one end side (front side) in the longitudinal direction of the battery tray 30, and the cooling unit 60 is accommodated in the space S. The cooling unit 60 includes an evaporator (evaporator) 61. The evaporator 61 includes an introduction passage portion 62 that supplies a refrigerant for cooling before evaporation, and a discharge passage portion that discharges the refrigerant evaporated in the evaporator 61. 63 is connected. The introduction path portion 62 and the discharge path portion 63 are connected to an external compressor, a radiator, or the like (not shown). Further, the cooling unit 60 is provided with an opening 64 at a portion facing the evaporator 61.

  And the battery case 50 which comprises the battery pack 10 of this invention is provided with the cooling structure which can cool each battery 20 substantially uniformly with the cooling air supplied from the cooling unit 60. FIG. Hereinafter, this cooling structure will be described.

  First, a fan device 80 is connected to the cooling unit 60 via a fan duct 70. The fan device 80 and the fan duct 70 are fixed at positions facing the space S of the battery cover 40. The battery cover 40 is further formed with an air passage 100 through which the cooling air supplied from the fan device 80 passes.

  Specifically, the battery cover 40 is formed with a protruding portion 41 in which a part of the battery cover 40 protrudes upward, and a blower duct 42 that constitutes the air blowing path 100 is disposed in the protruding portion 41. ing. One end side of the air duct 42 is connected to the fan device 80. That is, one end side of the air duct 42 is connected to the cooling unit 60 via the fan device 80 and the fan duct 70. Therefore, by operating the fan device 80, the cooling air cooled by the cooling unit 60 is supplied to the air blowing path 100.

  Here, the air supply path 100 includes a main air supply path 101 and a distribution path 102 in the present embodiment. The main air passage 101 is provided in the central part of the battery case 50 in the short direction (hereinafter also referred to as the left-right direction) along the longitudinal direction of the battery case 50 (hereinafter also referred to as the front-rear direction). In other words, the main air passage 101 extends in a direction orthogonal to the direction in which the battery cells 21 constituting each battery 20 are arranged. The distribution path 102 is connected to the end of the main air passage 101 opposite to the fan device 80, and distributes the cooling air in a direction intersecting with the main air passage 101. In the present embodiment, the distribution path 102 is provided in a region facing the two batteries 20 on the rear side of the battery case 50, and is formed with a width wider than the main air supply path 101. In addition, the distribution path 102 is basically provided along the front-rear direction of the battery case 50, but extends at the end of the distribution path 102 in a direction intersecting the main air passage 101 (for example, an orthogonal direction). The extending portion 103 is provided.

  A portion of the air duct 42 that constitutes the distribution path 102 is provided with a lower opening 43 that allows cooling air to flow downward. In the present embodiment, as shown in FIG. 2, a plurality of lower openings 43 are formed in two rows in a portion constituting the distribution path 102 of the air duct 42. Further, left and right openings 44 that open toward the outside in the left and right direction of the battery case 50 are provided on both sides of each row of the lower openings 43. For example, in the present embodiment, the left and right openings 44 are also formed at the distal end portion of the extending portion 103.

  Further, in the present embodiment, a guide member 45 that guides cooling air flowing out from the lower opening 43 downward is provided in a portion inside the lower opening 43 provided in the air duct 42 (FIG. 3). reference). The guide member 45 is, for example, a plate-like member fixed to the air duct 42, and is provided in a portion facing the rib 31 over the left-right direction of the battery case 50. Note that a space is provided between the guide member 45 and the rib 31 so that the cooling air sufficiently flows.

  Hereinafter, the flow of the cooling air in the cooling structure of the battery pack 10 will be described.

  When the cooling of the battery 20 is started in the battery pack 10 having the above-described configuration, the fan device 80 is driven to cool the air by being drawn from the opening 64 in the cooling unit 60. That is, when air passes through the evaporator 61, heat is exchanged between the air and the evaporator 61 to cool the air and form cooling air.

  The cooling air CA cooled by the cooling unit 60 is once sucked into the fan device 80 via the fan duct 70 as shown by an arrow in FIG. 5 and then supplied to the air passage 100 (the air duct 42). . The cooling air CA is guided to the distribution path 102 through the main air supply path 101, and the flow is expanded in the distribution path 102. Then, the cooling air CA flows into the lower side of the battery case 50 from the lower openings 43 and the left and right openings 44 formed in the air duct 42. That is, the cooling air CA guided to the distribution path 102 flows to the lower side of the battery case 50 from the lower openings 43 and the left and right openings 44 while being distributed in the left-right direction of the battery case 50. At this time, since the cooling air CA is guided by the guide member 45, it reliably flows into the lower side of the battery case 50.

  Thereafter, the cooling air CA passes through the space between the guide member 45 and the rib 31 and flows around each battery 20 and between the battery cells 21 constituting each battery 20. Thereby, each battery 20 is favorably cooled by the cooling air CA. The cooling air (air) whose temperature has increased by cooling the battery 20 returns to the cooling unit 60 from the opening 64 and is cooled again.

  As described above, in the cooling structure for the battery pack 10 of the present invention, the cooling air CA supplied from the cooling unit 60 to the air passage 100 cools each battery 20 while circulating in the battery case 50 in the vertical direction, thereby cooling the cooling unit. Return to 60.

  Thereby, each battery 20 in the battery case 50 is effectively cooled by the cooling air, and all the batteries 20 are cooled substantially uniformly. Specifically, in the configuration of the present invention, the cooling air circulates in the battery case 50 in the vertical direction via the air blowing path 100. For this reason, each battery 20 is cooled by the cooling air CA flowing in the battery case 50 in one direction (from the rear to the front). Therefore, the temperature rise of the cooling air is suppressed as compared with the conventional cooling structure, and each battery 20 can be effectively cooled.

  Further, in the configuration of the present invention, the cooling air is distributed substantially evenly in the left-right direction of the battery case 50 by the distribution path 102, the lower opening 43, and the left and right openings 44, and flows into the lower side of the battery case 50. Yes. For this reason, the cooling air CA flows evenly around each battery 20. Therefore, all the batteries 20 in the battery case 50 can be cooled to a substantially uniform temperature, and the temperature difference between the batteries 20 can be kept small.

  Furthermore, in this embodiment, the air flow path 100 is formed in the protrusion part 41 which made only the left-right direction center part of the battery cover 40 protrude upwards. That is, the thickness of the battery case 50 excluding the protrusion 41 is relatively thin. Therefore, by mounting the battery pack 10 on the vehicle so that the protruding portion 41 is disposed under the vehicle backbone, there is an effect that the vehicle compartment space can be widened.

  Although one embodiment of the present invention has been described above, of course, the present invention is not limited to this embodiment.

  For example, in the above-described embodiment, the cooling air CA is supplied to the periphery of each battery 20 via the air passage 100. For example, as shown in FIG. The cooling air CA may be supplied from the opening 64 to the periphery of each battery 20, and the cooling air (air) that has passed around the battery 20 may be returned to the cooling unit 60 via the air blowing path 100.

  Even in such a reverse flow, the temperature variation of each battery 20 can be suppressed as described above by circulating the cooling air CA vertically in the battery case 50.

  In this case, it is preferable to distribute the cooling air CA in the left-right direction of the battery case 50 in the vicinity of the cooling unit 60. In addition, for example, it is preferable to prevent the condensed water from the evaporator 61 from flowing into the battery case 50 by providing a filter in the opening 64 of the cooling unit 60 or the like.

  In the above-described embodiment, the cooling unit 60 is provided with the main air passage 101 and the distribution passage 102 via the fan device 80. However, these arrangements are not particularly limited. For example, the cooling unit 60 includes the main air passage. 101 may be connected, and the fan device 80 may be disposed between the main air passage 101 and the distribution passage 102.

  In the above-described embodiment, the air duct 42 is provided in the protrusion 41. However, for example, the protrusion 41 itself may function as the air passage 100 without providing the air duct 42.

  Moreover, the distribution path 102 should just be the structure which can send out cooling air in the direction which cross | intersects the main ventilation path 101, and the extension part 103 does not necessarily need to be provided. Furthermore, the distribution path 102 itself may not be provided. In this case, it is preferable to provide a plurality of holes for distributing the cooling air to the left and right at the rear end of the main air passage.

  As described above, the present invention can be variously modified within a range not departing from the gist thereof.

DESCRIPTION OF SYMBOLS 10 Battery pack 20 Battery 21 Battery cell 22 Terminal part 30 Battery tray 31 Rib 40 Battery cover 41 Protrusion part 42 Air blow duct 43 Lower opening part 44 Right-and-left opening part 45 Guide member 50 Battery case 60 Cooling unit 61 Evaporator 62 Introduction path part 63 Discharge Road portion 64 Opening portion 70 Fan duct 80 Fan device 100 Air passage 101 Main air passage 102 Distribution passage 103 Extension portion

Claims (7)

A battery case that includes a battery, a battery tray, and a battery cover, in which the battery is accommodated, and a cooling unit that is provided on one end side in the longitudinal direction of the battery case and supplies cooling air into the battery case. A cooling structure for the battery pack,
The battery case has at least a main air passage provided along the longitudinal direction of the battery case at the center in the short direction of the battery case, and includes an air passage through which the cooling air passes.
A cooling structure for a battery pack, wherein cooling air supplied from the cooling unit circulates in the battery case in the vertical direction through the air passage and returns to the cooling unit.   2. The battery pack according to claim 1, wherein the air passage includes a distribution passage that is connected to an end portion of the main air passage and distributes the cooling air in a direction intersecting with the main air passage. Cooling structure.   The cooling structure for a battery pack according to claim 1 or 2, wherein the air blowing path is constituted by a projecting portion that projects the battery cover upward.   The cooling structure for a battery pack according to claim 3, wherein the air passage is formed by an air duct that is disposed in the protrusion and has one end connected to the cooling unit.   The battery pack cooling structure according to claim 4, wherein a lower opening for flowing the cooling air downward is provided in the vicinity of the other end of the air duct.   6. The guide member according to claim 1, further comprising a guide member that is provided on an inner side of the lower opening of the battery case and guides cooling air flowing out from the lower opening. Battery pack cooling structure.   Each of the batteries includes a plurality of battery cells arranged in parallel at a predetermined interval, and the main air passage is extended in a direction orthogonal to the direction in which the battery cells are arranged in parallel. The battery pack cooling structure according to claim 6.

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