JP2011134615A - Cooling structure of battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure of a battery pack capable of achieving uniformization of temperatures of respective batteries housed in a battery case. <P>SOLUTION: A wind-blasting channel 100 is provided with a main air conduit 101 prepared along a long-side direction of the battery case 50 at a center part in a short-side direction of the battery case 50 with one end side connected to a cooling unit 60, and cooling wind supplied from the cooling unit 60 to the air conduit 100 is to flow out from the other end of the main air conduit 101, circulate in an up-and-down direction inside a battery case 50, and return to the cooling unit 60. Further, the air conduit 100 includes a plurality of sub air conduits 102 prepared along a direction crossing the main air conduit 101 connected at a given interval to the main air conduit 101, and the cooling wind is to flow downward, not only from the other end of the main air conduit 101 but also from each sub air conduit 102. <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 includes a battery including 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 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 (see, for example, 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 the battery case is provided at a central portion in a short direction of the battery case along a longitudinal direction of the battery case, and one end side is the cooling unit. An air passage having a main air passage connected to the unit, and the cooling air supplied from the cooling unit to the air passage flows downward from the other end portion of the main air passage to move up and down in the battery case. And the air flow path is connected to the main air flow path at a predetermined interval to be connected to the main air flow path. It includes a plurality of sub air passages provided along a direction intersecting with the air passage, and the cooling air flows downward from each sub air passage along with the other end of the main air passage. The battery pack cooling structure is characterized.

  In the first aspect, since the battery is cooled when the cooling air flows in one direction in the battery case, the temperature rise of the cooling air is suppressed and each battery is effectively and substantially uniformly cooled. Furthermore, since the cooling air flows out from the sub air passage, each battery can be cooled more effectively and uniformly.

  According to a second aspect of the present invention, in the battery case, a plurality of the batteries are arranged in parallel along the longitudinal direction of the battery case, and the sub air passage is provided at a position corresponding to the space between the batteries. The battery pack cooling structure according to the first aspect is characterized by the above.

  In the second aspect, the cooling air can surely flow between the batteries from the sub air passage, and each battery can be cooled more effectively.

  According to a third aspect of the present invention, the air passage is formed by an air duct in which the cooling unit is connected to one end side, and a portion constituting the main air passage of the air duct is the battery cover. The battery pack cooling structure according to the first or second aspect is characterized in that the battery pack is disposed in a protruding portion protruding upward.

  In this 3rd aspect, since the 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. Moreover, since the thickness of parts other than the protrusion part of a battery case becomes comparatively thin, a vehicle interior space can be expanded by arrange | positioning a protrusion part under the backbone of a vehicle.

  According to a fourth aspect of the present invention, in the third aspect, the portion corresponding to the sub air passage of the air duct is provided with an injection port for flowing the cooling air downward. The battery pack has a cooling structure.

  In the fourth aspect, the cooling air can be flowed more favorably between the batteries from the injection port.

  According to a fifth aspect of the present invention, there is provided the battery pack cooling structure according to the fourth aspect, wherein the size of the injection port is larger toward the downstream side of the flow of the cooling air.

  In the fifth aspect, each battery can be cooled more uniformly by increasing the amount of cooling air blown from the injection port toward the downstream side of the flow of cooling air where the temperature of the cooling air becomes higher. .

  According to a sixth 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 fifth aspects is characterized by the above.

  In the sixth 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.

  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 power to a traveling motor of the electric vehicle, and is fixed to the vehicle body, although not shown. 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 the present embodiment, the five batteries 20 on the front side (left side in the drawing) of the battery case 50 are placed on the battery tray 30 so that the terminal portion 22 faces upward. Two batteries 20 on the rear side of 50 are placed such that the terminal portion 22 faces the front 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 liquid such as water 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. Note that the introduction passage portion 62 and the discharge passage portion 63 are connected to an external compressor 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.

  Here, the air supply path 100 includes a main air supply path 101, a sub air supply path 102, and a distribution path 103 in the present embodiment. The main air passage 101 is provided in the central portion 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 sub air passage 102 is connected to the main air passage 101 at a predetermined interval and extends along the short direction of the battery case 50. In the present embodiment, the sub air passage 102 extends in a region facing the rib 31 provided in each battery 20.

  The distribution path 103 is connected to the end of the main air passage 101 opposite to the fan device 80, and distributes cooling air in a direction intersecting with the main air passage 101. In the present embodiment, the distribution path 103 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 103 is basically provided along the longitudinal direction of the battery case 50, but extends at the end of the distribution path 103 in a direction (for example, a direction orthogonal to the main air passage 101). The extended portion 104 is provided.

  In the present embodiment, such an air passage 100 is constituted by an air duct 42 including a main duct 42a and a plurality of sub ducts 42b. Specifically, the battery cover 40 is formed with a protruding portion 41 with a portion protruding upward, and a main duct 42 a constituting the main air passage 101 and the distribution passage 103 is formed in the protruding portion 41. It is arranged.

  One end side of the main duct 42 a 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.

  Each sub duct 42b extends in a direction orthogonal to the main duct 42a to constitute the sub air duct 102. These sub ducts 42 b are respectively arranged in regions facing the ribs 31 between the batteries 20 arranged in parallel in the front-rear direction of the battery case 50. Each sub-duct 42b is provided with a plurality of injection ports 43 through which cooling air is blown. In addition, although it is preferable that the injection port 43 is provided in the lower part of the subduct 42b so that cooling air may go downstream, the formation position of this injection port 43 is not specifically limited.

  Further, a lower opening 44 that allows cooling air to flow downward is provided in a portion of the main duct 42a that constitutes the distribution path 103. In the present embodiment, as shown in FIGS. 2 and 3, a plurality of lower openings 44 are formed in two rows in a portion constituting the distribution path 103 of the main duct 42 a. In addition, left and right openings 45 that open toward the outside in the left and right direction of the battery case 50 are respectively provided on both sides of each row of the lower openings 44. For example, in the present embodiment, the left and right openings 45 are also formed at the distal end portion of the extended portion 104.

  Furthermore, in the present embodiment, a guide member 46 that guides cooling air flowing out from the lower opening 44 downward is provided in a portion inside the lower opening 44 provided in the main duct 42a. The guide member 46 is, for example, a plate-like member fixed to the main duct 42 a, and is provided across the left and right directions of the battery case 50 at a portion facing the rib 31. A sufficient space for the cooling air to flow is secured between the guide member 46 and the rib 31.

  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 into the cooling unit 60 from the opening 64. 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 passage 103 through the main air passage 101 and also flows into the sub air passage 102.

  As shown in FIGS. 5A and 5B, the flow of the cooling air CA guided to the distribution path 103 is expanded in the distribution path 103. The cooling air CA flows into the lower side of the battery case 50 from the lower openings 44 and the left and right openings 45 formed in the main duct 42a. That is, the cooling air CA guided to the distribution path 103 flows to the lower side of the battery case 50 from the lower openings 44 and the left and right openings 45 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 46, 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 46 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.

  On the other hand, the cooling air CA that has flowed into the sub air passage 102 through the main air passage 101 is distributed in the left-right direction of the battery case 50 and blown out between the batteries 20 from the respective injection ports 43 (FIG. 5C). reference). And it joins with the flow of the cooling air CA from the back side of the battery case 50, and is sent ahead of the battery case 50 (refer FIG.5 (b)).

  Thus, in the cooling structure of 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 opening the opening. 64 returns to the cooling unit 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.

  In particular, in the present invention, the sub air passage 102 extends between the adjacent batteries 20, and the cooling air flows between the batteries 20 through the sub air passage 102, so that the temperature variation of each battery 20 is more reliably ensured. Can be suppressed.

  In addition, it is preferable that the injection port 43 formed in the sub duct 42b which comprises the sub ventilation path 102 becomes large toward the downstream of the flow of the cooling air CA. For example, in the present embodiment, it is preferable that the injection port 43 be formed larger toward one end side (front end side) in the longitudinal direction of the battery case 50. In addition, enlarging the injection port 43 includes not only increasing the diameter of each injection port 43 but also increasing the number of injection ports 43 formed in each sub duct 42b.

  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 103, the lower opening 44, and the left-right opening 45, 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 main air flow path 101 which comprises the air flow path 100 is formed in the protrusion part 41 which made only the short 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 main air passage 101 and the distribution passage 103 are provided in the cooling unit 60 via the fan device 80. However, these arrangements are not particularly limited. For example, the main air passage in the cooling unit 60 is provided. 101 may be connected, and the fan device 80 may be disposed between the main air passage 101 and the distribution passage 103.

  In the above-described embodiment, the air duct 42 is provided in the protrusion 41. For example, the protrusion 41 itself functions as the main air passage 101 and the distribution passage 103 without providing the air duct 42. May be.

  In addition, the distribution path 103 may be configured so that the cooling air can be sent out in a direction intersecting with the main air supply path 101, and the extending portion 104 is not necessarily provided. Furthermore, the distribution path 103 itself may not be provided.

  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 duct 42a Main duct 42b Sub duct 43 Injection port 44 Lower opening part 45 Right and left opening part 46 Guidance member 50 Battery case 60 Cooling unit 61 Evaporator 62 Introducing path 63 Discharging path 64 Opening 70 Fan duct 80 Fan device 100 Air path 101 Main air path 102 Sub air path 103 Distribution path 104 Extension section

Claims (6)

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 battery pack cooling structure,
Provided at the center of the battery case in the short direction along the longitudinal direction of the battery case and having a main air passage having one end connected to the cooling unit and supplied from the cooling unit to the air passage The cooling air is flowed downward from the other end portion of the main air passage and circulates in the battery case in the vertical direction to return to the cooling unit.
The air passage includes a plurality of sub air passages that are connected to the main air passage at predetermined intervals and are provided along a direction intersecting with the main air passage, and together with the other end of the main air passage, A cooling structure for a battery pack, wherein the cooling air flows downward also from a sub air passage.   In the battery case, a plurality of the batteries are arranged in parallel along the longitudinal direction of the battery case, and the sub air passage is provided at a position corresponding to the space between the batteries. Item 4. The battery pack cooling structure according to Item 1.   The air passage is formed by an air duct having the cooling unit connected to one end side thereof, and a portion constituting the main air passage of the air duct is in a projecting portion that projects the battery cover upward. The battery pack cooling structure according to claim 1, wherein the battery pack cooling structure is arranged.   4. The battery pack cooling structure according to claim 3, wherein a portion of the air duct corresponding to the sub air passage is provided with an injection port through which the cooling air flows downward. 5.   The cooling structure of the battery pack according to claim 4, wherein the size of the injection port is larger toward the downstream side of the flow of the cooling air.   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 5.

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