Cooling structure for vehicle batteries

Abstract

To provide a cooling structure of a vehicle battery which can reduce a temperature difference between battery modules to inhibit variations of a battery life with a simple structure.SOLUTION: A cooling structure of a vehicle battery includes: a battery assembly part in which multiple battery modules are arranged along a vehicle fore and aft direction; an air inlet which is located at the front relative to the battery assembly part in the vehicle fore and aft direction and into which outside air during traveling of a vehicle is blown; a heat exchanger; and a cooling passage which is located between the battery assembly part and the heat exchanger and in which a heat medium for cooling the battery module circulates. In the battery assembly part, a temperature of the battery module is further decreased by the heat medium as the battery module is located closer to the rear in the vehicle fore and aft direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a cooling structure for a vehicle battery.

Background Art

[0002] Conventionally, vehicles equipped with a battery pack as a power source are known. Since the temperature rise of the battery module during charging and discharging is relatively significant, the battery pack usually has cooling means for avoiding deterioration due to the temperature rise. Such cooling means tend to cause a temperature difference between a plurality of battery modules in the battery pack. Therefore, there is a technique for reducing the temperature difference between the plurality of battery modules to suppress variations in battery life.

[0003] For example, Patent Document 1 describes a cooling mechanism for cooling a plurality of secondary batteries, in which a first refrigerant path and a second refrigerant path are in a countercurrent flow with respect to each other. The first refrigerant path and the second refrigerant path are each connected to a different external refrigerant path.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The cooling mechanism described in Patent Document 1 has a complicated configuration including a refrigerant path. To set such a cooling mechanism in the housing (case) of the battery pack, the weight of the battery pack increases and the manufacturing cost also increases.

[0006] This invention was proposed to address these circumstances and aims to provide a cooling structure for vehicle batteries that can reduce temperature differences between battery modules and suppress variations in battery life with a simple configuration. [Means for solving the problem]

[0007] The cooling structure for a vehicle battery according to the present invention comprises a battery assembly section in which a plurality of battery modules are arranged along the longitudinal direction of the vehicle, an air intake located in front of the battery assembly section in the longitudinal direction of the vehicle and into which outside air is blown in while the vehicle is in motion, a heat exchanger, and a cooling channel through which a heat transfer medium for cooling the battery modules circulates between the battery assembly section and the heat exchanger, wherein the battery assembly section is cooled more by the heat transfer medium the battery modules are located further back in the longitudinal direction of the vehicle. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a cooling structure for a vehicle battery that can reduce temperature differences between battery modules and suppress variations in battery life with a simple configuration. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic side view showing an example of a vehicle equipped with the battery cooling structure of the first embodiment. [Figure 2] This is a schematic side view showing an example of a battery cooling structure according to the first embodiment. [Figure 3] This is a schematic top view showing an example of a battery cooling structure according to the first embodiment. [Figure 4] This is a schematic top view showing a modified example of the battery cooling structure of the first embodiment. [Figure 5] This is a schematic side view showing an example of a battery cooling structure according to the second embodiment. [Figure 6] This is a schematic top view showing an example of a battery cooling structure according to the second embodiment. [Figure 7]This is a schematic top view showing a modified example of the battery cooling structure of the first embodiment. [Figure 8] This is a schematic top view showing a modified example of the battery cooling structure of the first embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described with reference to the drawings. In each drawing, the same components will not be described.

[0011] In each figure, the direction indicated by arrow X (hereinafter also referred to as "X direction") is the forward direction of vehicle A in the vehicle's longitudinal direction (vehicle travel direction), the direction indicated by arrow Y (hereinafter also referred to as "Y direction") is the right direction of vehicle A in the vehicle's width direction (left-right direction), and the direction indicated by arrow Z (hereinafter also referred to as "Z direction") is the upward direction of vehicle A in the vehicle's vertical direction (height direction). The opposite direction of X is the rear direction of vehicle A in the vehicle's longitudinal direction (vehicle reverse direction), the opposite direction of Y is the left direction of vehicle A in the vehicle's width direction, and the opposite direction of Z is the downward direction of vehicle A in the vehicle's vertical direction (height direction).

[0012] In each diagram, the front side is the side closer to the X direction (further forward), and the rear side is the side closer to the opposite direction of the X direction (further rear). The right side is the side closer to the Y direction (further right), and the left side is the side closer to the opposite direction of the Y direction (further left). The top side is the side closer to the Z direction (further up), and the bottom side is the side closer to the opposite direction of the Z direction (further down). Furthermore, front / back, left / right, and up / down refer to the front / back in the vehicle's longitudinal direction, the left / right in the vehicle's width direction, and the up / down in the vehicle's vertical direction (height direction).

[0013] <First Embodiment> First, a first embodiment of the battery cooling structure for a vehicle according to the present invention will be described. Figure 1 shows a vehicle A equipped with the battery cooling structure 1 of the first embodiment. Vehicle A is an electric vehicle (EV) as an example of a vehicle that uses a battery as a power source. However, vehicle A is not limited to this and may be any other vehicle that has a battery as a power source, such as a hybrid vehicle or a fuel cell vehicle.

[0014] As shown in Figure 1, seats 4, including the driver's seat, are provided on the floor panel 3 inside the vehicle body 2 of vehicle A. Inside the vehicle body 2 are a steering wheel 5, an engine (not shown), a motor, a control device, etc. The battery cooling structure 1 comprises a front grille opening (air inlet) 11 located at the very front of the vehicle body 2, a heat exchanger 13 and a pump 14, a battery pack (battery housing) 15, an air inlet 16 formed in the bottom (under cover) 12, and a cooling passage 17. The heat exchanger 13 and the pump 14 are installed on the bottom 12 inside the front section 6. As shown in Figures 1 and 2, the battery pack 15 is mounted on the bottom 12 below the floor panel 3 (i.e., under the floor). The housing (case) 18 of the battery pack 15 is fixed to the bottom 12 by bolts (not shown).

[0015] As shown by the solid arrows in Figures 2 and 3, the battery cooling structure 1 takes in outside air from the front grille opening (air inlet) 11 on the front side in the vehicle's longitudinal direction and exhausts that outside air from the rear side in the vehicle's longitudinal direction. At the bottom 12, the air inlet 16 is formed on the side in front of the battery pack (battery housing) 15 in the vehicle's longitudinal direction.

[0016] The cooling channel 17 is formed in the shape of a pipe and connects the heat exchanger 13 in the front section 6 to the battery manifold 200, which will be described later, in the battery pack (battery housing section) 15.

[0017] The heat exchanger 13 is connected to the pump 14 via the cooling flow path 17. The pump 14 is connected to the flow path plate 231 via the cooling flow path 17. Also, the heat exchanger 13 is connected to the flow path plate 233 via the cooling flow path 17.

[0018] The heat exchanger 13 is, as an example, a radiator. The heat exchanger (radiator) 13 is arranged such that its front face faces the front grill opening (air intake) 11 side and its back face faces the battery pack 15 side. Note that the posture in which the heat exchanger 13 is arranged is not limited to this and may be changed as appropriate.

[0019] The battery pack 15 houses a battery assembly 200 within its housing (case) 18. The battery assembly 200 is formed by arranging a plurality of battery modules 20 along the vehicle's front-rear direction. The housing 18 of the battery pack 15 is formed in a box shape whose length in the front-rear direction is longer than its length in the left-right direction. A front opening 21 is formed in the front side face of the housing 18, and a rear opening 22 is formed in the rear side face of the housing 18.

[0020] During the running of vehicle A, the outside air (running wind) blown into the front part 6 of the vehicle body 2 from the front grill opening (air intake) 11 hits the front face side of the heat exchanger (radiator) 13, passes through the core part (radiator core) inside the heat exchanger 13 (not shown), and exits to the back face side of the heat exchanger 13. At that time, in the heat exchanger 13, heat exchange is performed between the running wind and the heat medium, and the heat medium is cooled. Note that "during running" means that vehicle A is in the middle of running in its forward direction (vehicle traveling direction, X direction).

[0021] The running wind blown into the space between the underfloor of the vehicle body 2 and the bottom (under cover) 12 from the front grill opening (air intake) 11 and passing through the heat exchanger 13, and the running wind blown into this space from the blow-in port 16 both flow in the vehicle's reverse direction. Then, the running wind flowing into the housing 18 from the front opening 21 of the battery pack 15 flows while contacting the battery module 20, exits from the rear opening 22 to the outside of the housing 18, and is discharged to the outside of vehicle A.

[0022] When the pump 14 is operating, it circulates the heat transfer medium within the cooling passage 17. The pump 14 is, for example, a water pump, but is not limited to this and may be any pump. The heat transfer medium is, for example, water, but is not limited to this and may be any other liquid, such as coolant (cooling water).

[0023] When the pump 14 is activated, the water heat transfer medium cooled in the heat exchanger (radiator) 13 flows through the cooling channel 17 in the direction indicated by the dotted arrow in Figure 3 and into the housing 18 of the battery pack 15. Inside the housing 18, the water heat transfer medium is heated by heat transfer from the battery module 20. The water heated inside the housing 18 returns to the heat exchanger 13 via the cooling channel 17, as indicated by the dotted arrow.

[0024] As shown in Figures 2 and 3, the battery module 20 comprises six battery cells 20-2 housed within a battery case 20-1. The battery case 20-1 has a structure that allows for ventilation both inside and out. Within the battery case 20-1, there is a gap between the battery cells 20-2 and the battery case 20-1, except for the bottom surface of each battery cell 20-2. These six battery cells 20-2 are spaced apart from each other and arranged in parallel in a direction approximately perpendicular to the airflow while driving (i.e., left-right direction).

[0025] As shown in Figure 3, three such battery modules 20 are arranged within the housing 18 of the battery pack 15, spaced apart along the vehicle's longitudinal direction. In other words, the battery pack 15 contains 18 battery cells 20-2, spaced apart from each other to allow for ventilation.

[0026] While vehicle A is in motion, when airflow enters the housing 18 of the battery pack 15, this airflow flows through the gaps between the parallel battery cells 20-2 and the gaps between the battery cells 20-2 and the battery case 20-1, and blows out in the direction of the vehicle's reverse movement. The battery cells 20-2 are cooled by the passage of this airflow.

[0027] Battery cell 20-2 is, as an example, an all-solid-state battery cell. An all-solid-state battery cell is made by mixing and solidifying powders of the active materials for the positive and negative electrodes with powders of a solid electrolyte, and is a battery whose temperature can be controlled within the temperature range of the airflow while driving. Note that battery cell 20-2 is not limited to this, and may be a cell from another type of battery, for example, a lithium-ion battery cell.

[0028] Furthermore, the number of battery cells 20-2 arranged in the left-right direction in the battery module 20 is not limited to this, and may be one or more. Also, the number of battery modules 20 arranged in the front-to-back direction in the battery assembly 200 within the housing 18 is not limited to this, and may be one or more.

[0029] Within the cooling channel 17, water, which is a heat transfer medium for cooling the battery module 20 between the battery manifold 200 and the heat exchanger 13, circulates. Inside the housing 18 of the battery pack 15, a channel plate 23 is provided that partially constitutes the cooling channel 17. The cross-sectional area of ​​the channel cross-section of the cooling channel 17 is substantially the same at all cross-sections, but is not limited to this, and may be non-identical at different cross-sectional locations.

[0030] The plate portion 24 of the flow channel plate 23 has tubular spaces that partially constitute the cooling channels 17. The cooling channels 17 formed in this plate portion 24 are arranged in a meandering (bent) manner so that multiple channels are arranged in parallel.

[0031] As shown in Figures 2 and 3, the flow path plates 23 are positioned opposite the battery module 20. Specifically, the flow path plates 23 are in contact with the underside of the battery module 20. Within the housing 18 of the battery pack 15, three such flow path plates 23 are arranged along the vehicle's longitudinal direction (flow path plates 231-233). Note that the flow path plates 23 may also be installed to contact a surface other than the underside of the battery module 20.

[0032] Water heated by the battery pack 15 flows into the heat exchanger (radiator) 13 through the cooling channel 17. The heat exchanger 13 cools the water, which is the heat transfer medium that flows in through the cooling channel 17, by heat exchange with the airflow blown in through the front grille opening (air inlet) 11. The water cooled in the heat exchanger 13 flows into the flow channel plate 23 inside the housing 18 of the battery pack 15 through the cooling channel 17.

[0033] Note that the heat exchanger 13 may be configured in a different way than a radiator. Vehicle A is equipped with a heat pump type air conditioning system, and the heat exchanger 13 may be an absorber (evaporator) of this air conditioning system. If the heat exchanger 13 is this absorber, vehicle A can sufficiently cool the water that flows into the heat exchanger 13 via the cooling channel 17, even in situations where there is no or insufficient airflow from driving, such as when the vehicle is stopped or driving slowly.

[0034] As shown by the solid arrows in Figures 2 and 3, the airflow blown into the intake port 16 flows forcefully into the housing 18 of the battery pack 15 through the front opening 21. Of the battery modules 20 inside the housing 18, the battery module 20 located on the flow path plate 231, which is the furthest forward in the vehicle's longitudinal direction, is directly blown by the airflow that flows into the housing 18.

[0035] Thus, in the space between the underbody 2 and the bottom 12 of the vehicle body, the airflow is drawn in from the front of the battery module 20, so the battery module 20, which is located at the very front in the vehicle's longitudinal direction, receives sufficient airflow. For this reason, the battery module 20 on the flow path plate 231 located at the very front in the longitudinal direction within the housing 18 of the battery pack 15 is cooled the most by the airflow that flows into the housing 18.

[0036] On the other hand, battery modules 20 located further back are blocked by the battery modules 20 in front of them, preventing them from receiving sufficient airflow. Furthermore, as the vehicle moves in the reverse direction (opposite to the X direction), the temperature of the airflow tends to rise due to heat transfer from the battery modules 20, potentially reducing its cooling effect. For these reasons, battery modules 20 located further back in the vehicle's front-to-rear direction are less likely to be cooled by airflow.

[0037] Furthermore, as the water used as a heat transfer medium, cooled by the heat exchanger 13, flows through the housing 18 of the battery pack 15 in the direction of vehicle reversal, its temperature is more likely to rise due to heat transfer from the battery module 20 located above it, potentially reducing its cooling effect.

[0038] Due to these factors, it is necessary to suppress the temperature rise of the battery modules 20 located at the rear in the vehicle's longitudinal direction and to reduce the temperature difference between the battery modules 20 in the vehicle's longitudinal direction. For this reason, in the battery cooling structure 1, within the housing 18 of the battery pack 15, the battery modules 20 located at the rear in the vehicle's longitudinal direction are cooled more by the water circulating in the cooling channel 17.

[0039] Specifically, the battery cooling structure 1 has flow channels 231, 232, and 233 within the housing 18 of the battery pack 15, with the flow channel volume increasing as the flow channel plate 23 is located further back in the vehicle's longitudinal direction. As shown in Figure 3, the flow channel volume is increased by increasing the number of bends (meanders) in the formed cooling flow channel 17 as the flow channel plate 231, 232, and 233 are connected, thereby making the cooling flow channel 17 longer. As a result, the battery module 20 located further back in the vehicle's longitudinal direction has a larger flow channel volume in the opposing cooling flow channel 17, and is therefore cooled more effectively by the heat transfer medium, water.

[0040] Thus, in the battery cooling structure 1, the battery module 20 located at the front in the vehicle's longitudinal direction is cooled mainly by the airflow blown in through the intake port 16. On the other hand, in the battery cooling structure 1, the battery module 20 located at the rear in the vehicle's longitudinal direction, which is less easily cooled by the airflow, is cooled more effectively by increasing the flow volume of the opposing flow channel plate 23.

[0041] The battery cooling structure 1, with its simple configuration and without requiring a complex cooling mechanism, can reduce temperature differences between battery modules 20 and suppress variations in battery life. Furthermore, the battery cooling structure 1 can improve cooling efficiency by using both airflow cooling and cooling with a heat transfer medium when cooling the battery modules 20. This battery cooling structure 1 is particularly useful when all-solid-state battery cells capable of temperature control within the airflow temperature range are used as battery cells 20-2.

[0042] In the example shown in Figure 3, the area of ​​the plate portion 24 (plate portion 241, plate portion 242, plate portion 243) increases with increasing number of bends (serpentines) in the cooling channel 17, as the channel plate 23 that contacts the underside of the battery module 20 located at the rear in the vehicle's longitudinal direction increases. This allows for rapid cooling of a wide area of ​​the battery module 20 located at the rear in the vehicle's longitudinal direction. Alternatively, the example shown in Figure 4 may be used instead.

[0043] In the battery cooling structure 1A shown in Figure 4, within the housing 18 of the battery pack 15a, the cooling channels 17a formed on the channel plates 23a that are in contact with the battery module 20 located at the rear in the vehicle's longitudinal direction have a greater number of bends (meanders), resulting in a larger channel volume.

[0044] However, in the battery cooling structure 1A, as the flow path plate 23a progresses from flow path plate 231a to flow path plate 232a to flow path plate 233a, the area of ​​the plate portion 24a (plate portion 241a, plate portion 242a, plate portion 243a) is not increased, but rather their areas are kept approximately the same. Furthermore, as the flow path plate progresses from flow path plate 231a to flow path plate 232a to flow path plate 233a, the spacing between the parallel cooling flow paths 17a is narrowed by bending (serpentine) to form denser serpentine cooling flow paths 17a, thereby increasing the flow path volume.

[0045] Thus, the battery cooling structure 1A can reduce the temperature difference between battery modules 20 with a simple configuration, thereby suppressing variations in battery life. Furthermore, the battery cooling structure 1A can improve cooling efficiency by using both airflow and a heat transfer medium to cool the battery modules 20. In addition, the battery cooling structure 1A does not change the area of ​​the plate portion 24a according to the number of meanders in the cooling channel 17a of the flow path plate 23a, but rather keeps the area of ​​the plate portion 24a approximately the same, so it is possible to use plate portions 24a with the same configuration (same shape, same area).

[0046] <Second Embodiment> Next, a second embodiment of the vehicle battery cooling structure (battery cooling structure) according to the present invention will be described. As shown in Figures 5 and 6, the battery cooling structure 1B of the second embodiment consists of a battery pack 15b installed in the same position as the battery pack 15 of the first embodiment. The battery pack 15b constituting the battery cooling structure 1B includes a battery manifold 200, a heat exchanger (radiator) 13b, a pump 14b, a fan 26, and a motor 27 within its housing 18. Furthermore, a cooling channel 17b connecting the heat exchanger 13b and the battery manifold 200 is provided within the housing 18. The size of the heat exchanger (radiator) 13b is smaller than, for example, the heat exchanger (radiator) 13 described above, and the size of the pump 14b is smaller than, for example, the pump 14 described above.

[0047] The heat exchanger 13b is connected to the pump 14b via the cooling channel 17b. The pump 14b is connected to the flow channel plate 233b via the cooling channel 17b. The heat exchanger 13b is also connected to the flow channel plate 231b via the cooling channel 17b.

[0048] Furthermore, an air intake port 16b and a secondary air intake port 25 are formed on the bottom surface of the housing 18 of the battery pack 15b. On the bottom surface of the housing 18, the air intake port 16b is formed on the side in front of the battery manifold 200 in the vehicle's longitudinal direction.

[0049] The heat exchanger (radiator) 13b is installed behind the battery manifold 200 in the vehicle's longitudinal direction. Due to its position, the heat exchanger 13b is not easily hit by the airflow blown in through the front opening 21 on the front side of the housing 18. Therefore, a secondary air intake 25 is provided on the bottom of the housing 18 between the battery manifold 200 and the heat exchanger 13b in the vehicle's direction of travel. As a result, when airflow blows into the housing 18 through the secondary air intake 25, it is directed towards the heat exchanger 13b.

[0050] Furthermore, in the battery pack 15b that constitutes the battery cooling structure 1B, flow path plates 23b (flow path plate 231b, flow path plate 232b, flow path plate 233b) with substantially identical configurations are arranged below the battery manifold 200. That is, the configuration of the plate sections 24b (plate sections 241b, plate sections 242b, plate sections 243b) is substantially identical, and the shape of the cooling flow paths 17b inside them (number of bends, spacing between cooling flow paths 17b that are parallel due to bends, etc.) is substantially identical.

[0051] While vehicle A is in motion, the airflow from the battery pack 15b, which is blown into the housing 18 through the front opening 21 on the front side of the housing 18, the air intake 16b on the bottom of the housing 18, and the secondary air intake 25, flows from the front to the rear in the longitudinal direction of the vehicle, as shown by the solid arrows in Figures 5 and 6.

[0052] The battery module 20, located at the foremost end of the battery assembly 200 in the front-to-back direction, is directly cooled by the airflow that flows into the housing 18 from both the front opening 21 and the air intake 16b.

[0053] In the battery cooling structure 1B (battery pack 15b), the cooling effect of the airflow decreases as the vehicle moves in the reverse direction (opposite to the X direction) due to heat transfer from the battery module 20. Therefore, in the battery cooling structure 1B, the battery module 20 located further back in the vehicle's front-to-rear direction is less effectively cooled by the airflow.

[0054] In the battery cooling structure 1B, water heated by the battery modules 20 of the battery assemblies 200 flows into the heat exchanger 13b located behind the battery assemblies 200 in the vehicle's longitudinal direction via the cooling channel 17b. The heat exchanger 13b cools the incoming water by exchanging heat with the airflow blown in through the auxiliary inlet 25.

[0055] As shown by the dotted arrows in Figure 6, the water cooled by the heat exchanger 13b flows sequentially through the cooling channel 17b to the channel plates 233b, 232b, and 231b below the battery manifold 200. The water flowing through the cooling channel 17b of channel plate 233b has a sufficient cooling effect because it is water that has been cooled by the heat exchanger 13b flowing directly into it. However, as the water moves in the direction of vehicle travel, from channel plate 233b to channel plate 232b and channel plate 231b, the temperature of the water in the cooling channel 17b tends to rise due to heat transfer from the battery module 20 located above it, which may reduce the cooling effect.

[0056] Thus, in the battery pack 15b that constitutes the battery cooling structure 1B, the heat exchanger 13b is positioned behind the battery manifold 200 in the vehicle's longitudinal direction, and the water cooled by the heat exchanger 13b flows from the rear to the front in the vehicle's longitudinal direction. As a result, the battery modules 20 that constitute the battery manifold 200 are cooled more by the water in the cooling channel 17b the further they are located towards the rear in the vehicle's longitudinal direction.

[0057] In the battery pack 15b comprising the battery cooling structure 1B described above, the battery module 20 on the flow channel plate 231b located at the front in the vehicle's longitudinal direction within the housing 18 is mainly cooled by the airflow while driving. On the other hand, the battery module 20 on the flow channel plate 233b located at the rear in the vehicle's longitudinal direction, which is difficult to cool by the airflow while driving, is mainly cooled by the water in the cooling channel 17b. As a result, the battery cooling structure 1B can reduce the temperature difference between the battery modules 20 in the vehicle's longitudinal direction and suppress variations in battery life.

[0058] Furthermore, the battery pack 15b, which constitutes the battery cooling structure 1B, is equipped with a fan 26 and a motor 27 for rotating the fan 26, located behind the heat exchanger 13b in the vehicle's longitudinal direction within the housing 18. In the battery cooling structure 1B, the rotational drive of the fan 26 based on the operation of the motor 27 ensures that outside air is blown into the auxiliary inlet 25 and onto the heat exchanger 13b, even in situations where there is no or insufficient airflow from driving, such as when the vehicle is stopped or driving slowly.

[0059] Therefore, even under such circumstances, the heat exchanger 13b can cool the water in the heat transfer medium with the outside air that is blown in. The battery module 20, located at the rear in the vehicle's longitudinal direction in the battery manifold 200, is sufficiently cooled by the water cooled by the heat exchanger 13b, as the water flows directly into the cooling channel 17b formed in the flow channel plate 23b below it.

[0060] In the battery cooling structure 1B, the rotational drive of the fan 26 causes outside air to be blown into the front opening 21 and the air intake 16b. Therefore, even in situations where there is no or insufficient airflow from driving, such as when the vehicle is stopped or driving slowly, the battery module 20 located at the front of the vehicle in the longitudinal direction within the housing 18 of the battery pack 15b is sufficiently cooled by this outside air. As a result, the battery cooling structure 1B can reduce the temperature difference between the battery modules 20 in the longitudinal direction of the vehicle, even in situations where there is no or insufficient airflow from driving, such as when the vehicle is stopped or driving slowly.

[0061] As described above, the battery cooling structure 1B can reduce the temperature difference between battery modules 20 with a simple configuration, thereby suppressing variations in battery life. Furthermore, the battery cooling structure 1B can improve cooling efficiency by using both airflow and a heat transfer medium to cool the battery modules 20. Moreover, by rotating the fan 26, the battery cooling structure 1B can reduce the temperature difference between battery modules 20 and suppress variations in battery life even in situations where airflow is absent or insufficient.

[0062] <Other examples> Embodiments of the present invention are not limited to the examples described above. Unlike the battery cooling structure 1 described above, in the battery cooling structure 1C of Figure 7, the shape of the cooling channels 17c formed in each of the flow path plates 23c within the housing 18 of the battery pack 15c (number of bends, spacing between cooling channels 17c arranged in parallel by bends, etc.) is substantially the same.

[0063] Furthermore, in the battery cooling structure 1C, the plate portions 24c of the flow path plate 23c are all formed of a thermally conductive material. The thermally conductive material forming the plate portions 24c is not particularly limited, but examples include metal materials with high thermal conductivity such as aluminum, copper, and iron.

[0064] Since the plate portion 24c is a thermally conductive material, it is cooled overall by heat transfer from the water in the cooling channel 17c. Therefore, the larger the contact area between the battery module 20 and the plate portion 24c that contacts its lower surface, the more it is cooled by heat transfer from the plate portion 24c.

[0065] As shown in Figure 7, in the battery pack 15c, the plate portion 24c of the flow channel plate 23c is larger as it is located towards the rear in the vehicle's longitudinal direction, such as the plate portion 241c of the flow channel plate 231c, the plate portion 242c of the flow channel plate 232c, and the plate portion 243c of the flow channel plate 233c. Consequently, the contact area with the battery module 20 is larger. As a result, the battery assembly portion 200 of the battery cooling structure 1C is cooled more by heat transfer from the heat-conducting plate portion 24c as it moves from the battery module 20 on the flow channel plate 231c, to the battery module 20 on the flow channel plate 232c, and to the battery module 20 on the flow channel plate 233c.

[0066] Thus, in the battery cooling structure 1C, the cooling effect of the flow channel plate 23c can be greatly increased simply by increasing the area of ​​the plate portion 24c by making it a thermally conductive material, without changing the shape of the cooling channel 17c formed in the flow channel plate 23c. Therefore, the battery cooling structure 1C can reduce the temperature difference between battery modules 20 with a simpler configuration, suppress variations in battery life, and reduce manufacturing costs. Furthermore, in the battery cooling structure 1C as well, the cooling efficiency can be increased by using both cooling by airflow and cooling by a heat transfer medium when cooling the battery modules 20.

[0067] Furthermore, unlike the battery cooling structure 1 described above, the battery cooling structure 1D shown in Figure 8 has a flow channel plate 23d with a cooling channel 17d formed in a plate portion 24d installed only on the underside of the battery module 20, which is located at the rearmost position in the vehicle's longitudinal direction, within the housing 18 of the battery pack 15d. In this way, the battery cooling structure 1D cools only the battery module 20, which is the least cooled by the airflow from the front while driving, with water in the cooling channel 17d.

[0068] The battery cooling structure 1D reduces the number of flow path plates 23d, resulting in a simpler configuration that reduces temperature differences between battery modules 20, thereby suppressing variations in battery life and lowering manufacturing costs. Furthermore, the battery cooling structure 1D achieves a lighter device by reducing the number of flow path plates 23d. In addition, the battery cooling structure 1D can improve cooling efficiency by using both airflow cooling and heat transfer fluid cooling when cooling the battery modules 20.

[0069] Furthermore, in the battery cooling structures 1, 1A, 1B, and 1D described above, the plate portions 24, 24a, 24b, and 24d may be formed from a thermally conductive material. In this case, the cooling effect of the flow path plates 23, 23a, 23b, and 23d on the battery module 20 can be further enhanced.

[0070] Furthermore, in the battery cooling structures 1, 1A, 1C, and 1D described above, the fan 26 and motor 27 may be provided behind the intake port 16 in the vehicle's longitudinal direction (for example, behind the housing 18). This allows the battery cooling structures 1, 1A, 1C, and 1D to draw in outside air through the intake port 16 into the space between the underbody 2 and the bottom 12, even in situations where there is no or insufficient airflow, such as when the vehicle is stopped or driving slowly.

[0071] In this case, the battery module 20 located at the front of the vehicle in the longitudinal direction in the battery assembly 200 is cooled by outside air drawn in through the air intake 16 by the rotational drive of the fan 26.

[0072] Thus, in battery cooling structures 1, 1A, 1C, and 1D, by providing a fan 26 and a motor 27, the same effect as when airflow is available can be obtained even in situations where no or insufficient airflow is available, such as when stopped or driving slowly.

[0073] Furthermore, in the battery cooling structures 1, 1A, 1B, 1C, and 1D described above, the housing 18 may be a two-layer structure, and its interior may be part of a cooling channel through which a heat transfer medium flows. This reduces the number of parts and thus lowers manufacturing costs. [Explanation of Symbols]

[0074] 1, 1A, 1B, 1C, 1D Battery cooling structure, 2 Body, 3 Floor panel, 4 Seat, 5 Steering wheel, 6 Front section, 11 Front grille opening (air inlet), 12 Bottom section, 13, 13b Heat exchanger, 14, 14b Pump, 15, 15a, 15b, 15c, 15d Battery pack, 16, 16b Inlet, 17, 17a, 17b, 17c, 17d Cooling passage, 18 Housing, 20 Battery module, 21 Front opening, 22 Rear opening, 23, 23a, 23b, 23c, 23d Passageway plate, 24, 24a, 24b, 24c, 24d Plate section, 25 Sub-inlet, 26 Fan, 27 Motor, 200 Battery manifold, A Vehicle

Claims

1. A cooling structure for a vehicle battery, A battery assembly section in which multiple battery modules are arranged along the front-to-rear direction of the vehicle, Located in the front-rear direction of the vehicle, ahead of the battery manifold, and having an air intake for outside air to blow in while the vehicle is in motion, Heat exchanger, Between the battery assembly and the heat exchanger, there is a cooling channel through which a heat transfer medium for cooling the battery module circulates. The aforementioned battery assemblies are The heat transfer medium cools the battery module more effectively the further it is located towards the rear in the vehicle's longitudinal direction. A cooling structure for a vehicle battery characterized by the following features.

2. A flow path plate that partially constitutes the cooling flow path is provided facing the battery module, The flow channel plate has a larger flow channel volume the further it is located towards the rear in the vehicle's longitudinal direction. The cooling structure for a vehicle battery according to feature 1.

3. A flow path plate that partially constitutes the cooling flow path is provided in contact with the battery module, The aforementioned flow channel plate is formed of a thermally conductive material, and the contact area with the battery module is larger the further back it is located in the vehicle's longitudinal direction. The cooling structure for a vehicle battery according to feature 1.

4. The heat exchanger is located behind the battery manifold in the vehicle's longitudinal direction. Between the battery manifold and the heat exchanger in the front-to-rear direction of the vehicle, there is a secondary air intake for outside air blown in while the vehicle is in motion. The cooling structure for a vehicle battery according to feature 1.

5. Equipped with a fan, The rotational drive of the aforementioned fan causes outside air to be blown into the intake port. A cooling structure for a vehicle battery according to any one of claims 1 to 4.

6. Equipped with a fan, The rotational drive of the aforementioned fan causes outside air to be blown into the aforementioned inlet and the aforementioned auxiliary inlet. Cooling structure for a vehicle battery according to feature 4.

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