Battery module cooling structure

Abstract

This battery module cooling structure comprises: a battery pack case (20) that has an internal space (20A) in which battery modules (30) are arranged side by side in a first direction, an air feed port (45B) to the internal space (20A), and an air discharge port (46C) to the internal space (20A); and partition parts (90) each of which extends in a horizontal second direction that intersects with the first direction, is disposed between adjacent battery modules (30), and is provided above on an inner bottom surface (51) of the battery pack case (20) in an upright manner so as to partition a lower space (20L). The partition parts (90) have a longer distance from one end on the side closer to the feed port (45B) in the second direction to one end of the internal space (20A) on the side closer to the feed port (45B) in the second direction as the partition parts (90) are disposed closer to the feed port (45B) with respect to the discharge port (46C) in the first direction.

Description

Battery module cooling structure

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

[0002] Vehicles such as electric vehicles and hybrid electric vehicles are equipped with large-capacity batteries (also called battery packs) as a power source for driving the vehicle. A known example of such large-capacity batteries is a battery pack containing multiple battery modules housed within the interior space of a battery pack case. The battery modules generate heat during power running, in which power is supplied to a drive motor, and during regeneration, in which the vehicle's braking energy is converted into electricity and charged. One proposed structure for cooling the heat-generating battery modules is one that cools the battery modules housed within the interior space of a battery pack case from below. For example, a structure in which a water-cooled cooling mechanism is provided in the space below the battery modules has been considered (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2023-141197

[0004] In the above-described structure in which a refrigerant is introduced into a space below the battery modules, it is possible to use air (i.e., cooling air) as the refrigerant. In this case, there is a risk that the refrigerant air may not be distributed evenly in the lower space (hereinafter also referred to as the "lower space") or that an excessive amount of refrigerant air may be supplied, resulting in insufficient balanced cooling of the multiple battery modules. Therefore, there is room for improvement in terms of balanced cooling of the multiple battery modules.

[0005] The battery module cooling structure of the present invention was invented in consideration of these problems, and one of its objectives is to cool multiple battery modules in a balanced manner. However, in addition to this objective, another objective of the present invention is to achieve effects derived from the configurations shown in the "Description of Embodiments" below, which are not obtainable with conventional technologies.

[0006] The disclosed battery module cooling structure can be realized as the following disclosed embodiments (application examples) and solves at least part of the above-mentioned problems. Each of the embodiments from embodiment 2 onwards is an embodiment that can be selected as an additional option, and each of the embodiments from embodiment 2 onwards is an embodiment that can be omitted. None of the embodiments from embodiment 2 onwards discloses an embodiment or configuration that is essential to the present invention.

[0007] Aspect 1. The disclosed battery module cooling structure includes a battery pack case and a partition. The battery pack case has an internal space in which three or more battery modules are arranged side by side in a horizontal first direction, an air inlet into the internal space, and an air outlet out of the internal space. The partitions extend in a horizontal second direction intersecting the first direction, are disposed between adjacent battery modules, and extend upward from the inner bottom surface of the battery pack case to separate a lower space between the electrical module and the inner bottom surface. The inlet and the outlet are located at different positions in the first direction and the second direction, respectively, and the three or more battery modules are arranged on a path connecting the inlet and the outlet. The distance from one end of the partition closer to the inlet in the second direction to one end of the internal space closer to the inlet in the second direction is longer for the partitions located closer to the inlet in the first direction relative to the outlet.

[0008] Aspect 2. In the above-mentioned Aspect 1, it is preferable that the inlet is provided at at least one of one end and the other end of the lower space in the first direction. Aspect 3. In the above-mentioned Aspect 2, it is preferable that the inlet is provided at each of one end and the other end of the lower space in the first direction, and the outlet is provided in a central portion between the inlet located at one end of the lower space in the first direction and the inlet located at the other end of the lower space in the vehicle width direction.

[0009] Aspect 4. In any one of Aspects 1 to 3 above, it is preferable that the partitions include at least one of long partitions that extend longer than the dimension of the battery module in the second direction and short partitions that extend shorter than the dimension of the battery module in the second direction.

[0010] Aspect 5. In any one of Aspects 1 to 4 above, it is preferable that a lower step portion be formed between a downstream bottom surface of the inner bottom surface that is located closer to the discharge outlet than the inlet in the second direction, and an upstream bottom surface of the inner bottom surface that is located closer to the inlet than the discharge outlet in the second direction and is lower than the downstream bottom surface.

[0011] Aspect 6. In any one of Aspects 1 to 5 above, it is preferable that the battery module cooling structure has an upper step portion formed between a downstream top surface of an inner top surface defining an upper end of the internal space, the downstream top surface being located closer to the outlet than the inlet in the second direction, and an upstream top surface of the inner top surface being located closer to the inlet than the outlet in the second direction and lower than the downstream top surface.

[0012] Aspect 7. In any one of Aspects 1 to 6 above, it is preferable that the battery module cooling structure further includes a baffle plate that is disposed above the battery modules and below a downstream top surface of an inner top surface that defines an upper end of the internal space and that is located closer to the outlet than the inlet in the second direction, and that obstructs air flow from below to above.

[0013] Aspect 8. In any one of Aspects 1 to 7 above, the partition section is preferably provided in a tapered shape such that the dimension in the first direction is longer on a side from the inlet toward the outlet in the second direction.

[0014] Aspect 9. In any one of Aspects 1 to 8 above, it is preferable that the battery pack case accommodates side modules, each of which is disposed at both ends of the battery modules in the first direction, and a center module, each of which is disposed centrally in the first direction, among the battery modules. In this case, it is preferable that the inner bottom surface has a side inner bottom surface located below the side modules and a center inner bottom surface located below the center module, and that the lower space has a side lower space formed between the side modules and the side inner bottom surface and provided with the inlet, and a center lower space formed between the center module and the center inner bottom surface, communicating with a lower part of the side lower space and having a smaller vertical dimension than the side lower space.

[0015] Aspect 10. In the above aspect 9, it is preferable that the side lower space is defined at a lower end by a slope surface that is positioned downward toward the center in the first direction in at least a portion of the side inner bottom surface.

[0016] According to the disclosed battery module cooling structure, a plurality of battery modules can be cooled in a balanced manner.

[0017] 1 is a longitudinal cross-sectional view, as seen from the front of the vehicle, showing a battery pack to which a battery module cooling structure according to an embodiment is applied and a portion of a structure provided around the battery pack. FIG. 2 is a cross-sectional view, as seen from above the vehicle, for explaining the basic structure of the battery pack of FIG. 1. FIG. 3 is a schematic diagram showing a path through which refrigerant air circulates in the internal space of the battery pack of FIG. 1. FIG. 4 is an exploded perspective view showing an overview of the battery pack of FIG. 1. FIG. 5 is a cross-sectional view, as seen from the front of the vehicle, showing the structure around an air intake in the battery pack of FIG. 1. FIG. 6 is a top view showing an air intake cover in the battery pack of FIG. 1. FIG. 7 is a cross-sectional view, as seen from above the vehicle, for explaining the cooling structure of the battery pack of FIG. 1, showing the relationship between a tray, a partition, and a battery module. FIG. 8 is a cross-sectional view, as seen from above the vehicle, for explaining the cooling structure of the battery pack of FIG. 7. FIG. 9 is a cross-sectional view, as seen from above the vehicle, showing the relationship between a battery module and a partition in the battery pack of FIG. 7. FIG. 10 is a cross-sectional view (corresponding to FIG. 7) for explaining a partition in a battery pack to which a battery module cooling structure according to a modified example is applied.

[0018] With reference to the drawings, embodiments of a structure relating to a battery mounted on a vehicle (including a battery module cooling structure) will be described. The embodiments described below are merely examples, and are not intended to exclude various modifications or applications of techniques not explicitly stated in the following embodiments. Various modifications of the configurations of the embodiments can be implemented without departing from the spirit thereof. Furthermore, the configurations can be selected or combined as needed.

[0019] In the following description, the forward direction of the vehicle is defined as the front, and the backward direction is defined as the rear, and left and right are defined based on the front. Since the left and right direction (first direction) is the width direction of the vehicle, in this embodiment, the left and right direction is referred to as the "vehicle width direction" of the vehicle. Furthermore, the up and down direction is defined with the direction of gravity as downward and the opposite direction as upward, and in this embodiment, the position in the up and down direction is referred to as the "height position." Note that the up and down direction does not have to completely coincide with the vertical direction and may be slightly inclined relative to the vertical direction. Similarly, the front and back direction of the vehicle (second direction, hereinafter simply referred to as the "front and back direction") and the vehicle width direction do not have to completely coincide with the horizontal direction.

[0020] Vehicle structures are often formed with near bilateral symmetry (mirror symmetry with respect to a plane including the yaw axis and roll axis passing through the center of gravity of the vehicle), but perfect symmetry is not required. Furthermore, the type of vehicle to which the structure according to the embodiment is applied is not particularly limited, and the structure can be applied to, for example, electric vehicles (EVs), hybrid vehicles (HEVs), plug-in hybrid vehicles (PHEVs), and the like. A plug-in hybrid vehicle is a hybrid vehicle capable of externally charging the battery or externally receiving power from the battery. A plug-in hybrid vehicle is provided with a charging port (inlet) for inserting a charging cable that supplies power from an external charging facility and a power outlet (outlet) for external power supply.

[0021] [I. One Embodiment] In the following one embodiment, three structures related to a battery (also called a battery pack) will be described: a battery mounting structure for mounting a battery in a vehicle; a battery pack air intake structure for taking air into the internal space of a battery pack case mounted in a vehicle; and a battery module cooling structure for cooling a battery mounted in a vehicle. Note that, because the three structures of the battery mounting structure, battery pack air intake structure, and battery module cooling structure are related to a vehicle battery, they can be collectively referred to as a vehicle battery structure, and when the battery is mounted in the lower part of the vehicle compartment, they can also be referred to as a vehicle lower structure, referring to the location where the battery is mounted. These three structures can also be expanded to be referred to as a vehicle structure.

[0022] [1. Configuration] [1-1. Basic Structure] Fig. 1 is a longitudinal cross-sectional view showing a battery pack 10 to which a battery module cooling structure according to an embodiment is applied and a portion of the structure provided around the battery pack 10, as viewed from the front side of the vehicle. Fig. 2 is a transverse cross-sectional view of the battery pack 10, as viewed from above the vehicle. Fig. 3 is a schematic diagram showing the path through which refrigerant air (hereinafter referred to as "cooling air") circulates in the internal space 20A of the battery pack 10, as viewed from the left side of the vehicle. Fig. 4 is an exploded perspective view showing an overview of the battery pack 10. As shown in Fig. 1, the battery pack 10 is provided in a vehicle interior 1, and various structures and members are provided around the battery pack 10.

[0023] <Peripheral Configuration of Battery Pack> A seat 2 for a passenger is provided above the battery pack 10. The seat 2 illustrated here is a front seat (front seat) among at least two rows of seats arranged in the longitudinal direction. For example, the driver's seat or the passenger seat is the seat 2. However, the seat 2 may be any front seat among multiple rows of seats arranged in the longitudinal direction, excluding the rearmost seat, and may be the frontmost seat or the second-to-front seat in a vehicle with three rows of seats arranged side by side.

[0024] In addition, a panel member 3 and a carpet 4 of the vehicle interior 1 are provided above the battery pack 10. The panel member 3 is a sheet metal member that forms the floor surface on which the carpet 4 is placed. The carpet 4 is laid above the panel member 3, and seats 2, such as the driver's seat and passenger seat, are arranged above the carpet 4 with a gap in the vehicle width direction. A console 5 is provided on the panel member 3 between the driver's seat and passenger seat that form the seats 2. The console 5 illustrated in FIG. 1 is provided separately from the panel member 3. This console 5 is provided with cup holders 5H.

[0025] A body floor 6 extends in a planar shape below the battery pack 10. A pair of left and right side members 7 extend in the front-rear direction below the body floor 6 and support from below a pair of left and right side floor members 6X, which are portions of the body floor 6 on the vehicle widthwise end sides (hereinafter also referred to as "outside sides in the vehicle width direction"). A center floor 6Y, which is a portion of the body floor 6 closer to the vehicle widthwise center (inner side in the vehicle width direction) than the side floors 6X, is located lower than the side floors 6X, and the upper and lower cross sections along the vehicle width direction are formed in a downwardly convex shape.

[0026] In the vehicle exemplified in this embodiment, an exhaust pipe 8 is provided below the body floor 6, extending in the longitudinal direction, on the vehicle widthwise inward side of the right (one side in the vehicle width direction) side member 7. The exhaust pipe 8 is a duct member that circulates exhaust gas from an engine (internal combustion engine) (not shown), and can also be considered a member that radiates exhaust heat. The space above the body floor 6 is the passenger compartment 1. In other words, since the lower end of the passenger compartment 1 is defined by the body floor 6, the battery pack 10 can also be considered to be mounted in the lower part of the passenger compartment 1.

[0027] <Configuration of Battery Pack> The battery pack 10 is a power storage device for a vehicle that houses multiple battery modules 30 in the internal space 20A of a battery pack case 20. Below, the configuration of the battery pack 10 will be described, including the configuration of the battery modules 30, the battery-related electrical components, and the cooling equipment, followed by the internal layout, and finally the battery pack case 20 located below the seat 2.

[0028] ==Battery Module== The battery module 30 is a secondary battery that can not only supply power but also charge. This battery module 30 generates heat when receiving and supplying power, such as during power running to supply power to the vehicle's drive motor (not shown) or during regeneration, when the vehicle's braking energy is converted into power and charged. The battery module 30 has a larger capacity than on-board batteries such as so-called 12V batteries and 24V batteries.

[0029] In the internal space 20A, a space (hereinafter referred to as the "lower space") 20L located below the battery module 30 and a space (hereinafter referred to as the "upper space") 20U located above the battery module 30 are formed above and below the battery module 30. As shown in Fig. 3, each battery module 30 is an assembled battery formed by connecting multiple battery cells 30C (single cells; only one cell is marked in Fig. 3). These battery cells 30C are connected in a combination of series and parallel connections depending on the design voltage, design capacity, etc. of the battery module 30.

[0030] 1 and 2 illustrate an example in which multiple battery modules 30 of the same size are arranged side by side in the vehicle width direction in the same orientation. Specifically, six rectangular parallelepiped battery modules 30 with the same dimensions in the vehicle width direction, front-rear direction, and up-down direction (i.e., proportions) are arranged side by side in the same orientation with the front-rear direction as the longitudinal direction. That is, the multiple battery modules 30 have the same length in the up-down direction and the same length in the front-rear direction. The battery modules 30 illustrated in this embodiment include, in order from left to right, a first battery module 31, a second battery module 32, a third battery module 33, a fourth battery module 34, a fifth battery module 35, and a sixth battery module 36.

[0031] Of these six battery modules 31 to 36, the four battery modules 32 to 35 arranged in the center in the vehicle width direction are referred to indistinguishably as the center module 15. Of the six battery modules 31 to 36, the battery modules 31 and 36 arranged at both ends in the vehicle width direction are referred to indistinguishably as the side modules 16. In other words, of the six battery modules 30, the ones located outermost on one and the other sides in the vehicle width direction are referred to as the side modules 16.

[0032] The internal space 20A housing the battery modules 30 houses various battery-related electrical components and cooling devices. ==Battery-related Electrical Components== As shown in Figure 1, the battery-related electrical components housed in the internal space 20A include a BMU (Battery Management Unit) 40, a transformer 41, a harness 42, and a junction box 43 (see Figures 2 to 4). The BMU 40 is an electronic control device that manages all of the battery modules 30, and has functions such as managing and monitoring the status of each battery module 30 and A / D conversion (analog-to-digital conversion) of control signals.

[0033] The transformer 41 is a device that converts voltage. This transformer 41 is, for example, a DC / DC converter that steps down and outputs the voltage applied from the battery module 30, and generates heat during voltage conversion. The harness 42 is an electric wire connected to the BMU 40, the transformer 41, the junction box 43, etc. The junction box 43 is a device that performs functions such as monitoring the amount of power transmitted from the battery pack 10 to the outside, cutting off the power, and distributing power to the transformer 41.

[0034] Cooling Equipment As shown in Fig. 4, an example of a cooling equipment housed in the internal space 20A is an intake duct 45. Examples of cooling equipment that is not housed in the internal space 20A but is attached to the outside of the battery pack case 20 include a fan 44 and an exhaust duct 46. The fan 44 is an air-cooled fan that supplies cooling air to cool the heat-generating battery modules 30 and the transformer 41. The intake duct 45 and the exhaust duct 46 are tubular members that form a flow path for the cooling air supplied by the fan 44.

[0035] Cooling by the cooling equipment is performed in the internal space 20A of the battery pack case 20 as outlined below. As shown in FIG. 3 , cooling air taken in from the space of the vehicle interior 1 (vehicle interior space) flows through the intake duct 45. The cooling air that has flowed through the intake duct 45 is introduced into the lower space 20L. The cooling air in the lower space 20L flows into the upper space 20U through gaps between the multiple battery cells 30C that make up each battery module 30. The cooling air flows from the lower space 20L to the upper space 20U, thereby cooling the battery modules 30. After cooling the transformer 41, the cooling air in the upper space 20U is discharged through the exhaust duct 46 by the fan 44.

[0036] In the illustrated embodiment, as shown in FIG. 4 , a pair of left and right intake ducts 45 are provided in the interior space 20A, and a fan 44 and an exhaust duct 46 are provided above the battery pack 10 and in the center of the vehicle width direction. The intake duct 45 has an intake port 45A at its upstream end in the direction of flow of cooling air and an inlet port 45B at its downstream end in the direction of flow of cooling air. The intake port 45A is an opening that takes in cooling air from the space of the vehicle interior 1 (vehicle compartment space) into the interior space 20A. The inlet port 45B is an opening that introduces cooling air into the interior space 20A. Specifically, the cooling air inlet port 45B into the interior space 20A is an opening that introduces cooling air into the lower space 20L. That is, cooling air that cools the battery module 30 is introduced from the inlet port 45B in the lower space 20L.

[0037] The air intake port 45A and the introduction port 45B are each provided in two locations, the same as the number of installed air intake ducts 45. Specifically, the air intake port 45A is provided at each of the left and right ends of the top surface of the battery pack case 20. Also, the introduction port 45B is provided at each of the left and right ends (one end and the other end in the first direction) of the lower space 20L. However, only one air intake duct 45 may be provided, and the introduction port 45B may be provided at either the left end or the right end of the lower space 20L.

[0038] Exhaust duct 46 extends to the outside of battery pack case 20. A fan 44 is connected to the upstream end of exhaust duct 46 in the direction of flow of cooled air (hereinafter also referred to as "cooled air"), and an exhaust port 46D is formed at the downstream end in the flow direction, through which the cooled air compressed by fan 44 is exhausted. The cooled air in exhaust duct 46 is exhausted from exhaust port 46D, for example, into the interior of an instrument panel (not shown).

[0039] 3, the cooling air in the upper space 20U flows to the fan 44 through an exhaust port 46C that communicates with the upper space 20U. The exhaust port 46C is an opening that exhausts the cooling air to the outside of the internal space 20A. Specifically, the exhaust port 46C for the cooling air to the outside of the internal space 20A is an opening that exhausts the cooling air from the upper space 20U. In other words, the cooling air that has cooled the battery modules 30 is exhausted from the exhaust port 46C of the upper space 20U.

[0040] 2, the illustrated outlet 46C is positioned differently from the inlet 45B in both the vehicle width direction and the front-rear direction. Specifically, the outlet 46C is positioned toward the center and rear of the inlet 45B in the vehicle width direction. In other words, focusing on the position in the vehicle width direction, the outlet 46C is provided in the center between the inlet 45B located on the left side and the inlet 45B located on the right side in the vehicle width direction.

[0041] A plurality of battery modules 30 are arranged on a linear path (hereinafter referred to as the "linear path") 49 that virtually connects the inlet 45B and the outlet 46C. In other words, the inlet 45B, the outlet 46C, and the battery modules 30 are arranged in a relative position such that the virtual linear path 49 crosses all of the battery modules 30.

[0042] Internal Arrangement Next, we will explain the arrangement of the battery modules 30, battery-related electrical components, and cooling equipment of the battery pack 10. As shown in Figure 4, the BMU 40, transformer 41, and junction box 43 are all arranged together in the center or front of the vehicle width direction in the internal space 20A.

[0043] 1 and 4 show an example in which the BMU 40 and transformer 41 are arranged above the center module 15 in the internal space 20A. Here, an arrangement in which the transformer 41 is located above the BMU 40 is illustrated. Furthermore, as shown in FIG. 2, the junction box 43 is arranged in front of the center module 15. Note that the BMU 40, transformer 41, and junction box 43 are not arranged above or in front of the side module 16. For this reason, it can be said that the side module 16 has a higher degree of freedom in setting the arrangement than the center module 15, but the center module 15 has more restrictions on changing the arrangement than the side module 16.

[0044] The harness 42 is connected to the BMU 40, the transformer 41, the junction box 43, etc., and is therefore routed at least above and in front of the center module 15. As shown in Fig. 4, the intake duct 45 extends outward in the vehicle width direction and forward of each of the left and right side modules 16. The intake duct 45 illustrated here has an intake port 45A located on the outer side of each side module 16 in the vehicle width direction in a plan view, and an inlet 45B located on the front side of each side module 16 in a plan view.

[0045] In addition, the fan 44 and exhaust duct 46 are disposed above the battery pack case 20 rather than in the interior space 20A. Here, the fan 44 is disposed above the transformer 41, and the exhaust duct 46 extends forward from the fan 44. As shown in FIG. 1 , the seat 2 is disposed above the battery pack 10 rather than the interior space 20A, and is installed above the second battery module 12 and the outer half of the fifth battery module 15 in the vehicle width direction, and above the entire side module 16. The battery pack case 20 mounted below the seat 2 in this manner will be described next.

[0046] ==Battery Pack Case== The battery pack case 20, in which the battery module 30, battery-related electrical components, and cooling equipment are arranged as described above, is mounted in the lower part of the vehicle interior 1 (lower part of the vehicle interior), and as shown in Figure 1, is composed of a tray 21 and a lid 22. The tray 21 is a cylindrical casing member with a bottom and an opening at the top. The lid 22 is a cover member that closes the opening of the tray 21.

[0047] The tray 21 has a bottom wall 50 and side walls 60 extending from the periphery of the bottom wall 50. The bottom wall 50 has an inner bottom surface 51 that defines the lower end of the internal space 20A. The "inner bottom surface 51" here refers to a planar portion exposed to the lower space 20L. The wall-like (plate-like) portion having the inner bottom surface 51 defined in this manner is the bottom wall 50. The inner bottom surface 51 extends below the battery module 30 through the lower space 20L. In other words, the battery module 30 and the inner bottom surface 51 are spaced apart.

[0048] In this embodiment, the inner bottom surface 51 is subdivided into two regions: a center inner bottom surface 51C located below the center module 15, and a side inner bottom surface 51S located below the side module 16. The lower space 20L is similarly subdivided into two regions: a center lower space 20C formed below the center module 15 and above the center inner bottom surface 51C, and a side lower space 20S formed below the side module 16 and above the side inner bottom surface 51S. The center lower space 20C and the side lower space 20S are provided in communication, allowing cooling air to circulate throughout the entire lower space 20L.

[0049] The exhaust pipe 8 is disposed directly below the end of the tray 21 (battery pack case 20) in the vehicle width direction. The lid 22 is a member that forms the top surface of the battery pack case 20. As shown in Figure 4, the lid 22 is provided with an air intake port 45A that takes in cooling air into the internal space 20A. Here, the air intake port 45A is provided on the top surface of the battery pack case 20 and faces upward, and an air intake port cover 70 is provided to cover the air intake port 45A.

[0050] [1-2. Battery Mounting Structure] The battery mounting structure relating to the layout of the battery modules 30 will be described in detail below. A structure in which all battery modules aligned in a predetermined direction are arranged at the same height (hereinafter referred to as "Comparative Structure 1") requires a surface on which all battery modules can be mounted at the same height (i.e., a mounting surface in an area where all battery modules extend at a certain height), which may cause interference with the surrounding structures of the battery modules. For example, as in this embodiment, if existing structures such as side members 7 and exhaust pipes 8 are present on the outer side of the battery pack 10 in the vehicle width direction, the battery modules on the outer side in the vehicle width direction may interfere with these existing structures in Comparative Structure 1. Therefore, measures such as redesigning the layout of the surrounding structures of the battery modules or reducing the number of battery modules are required.

[0051] Therefore, in the battery mounting structure of this embodiment, all battery modules 30 are not placed at the same height position, but the height position is set depending on the placement location of the battery module 30, thereby ensuring freedom in the layout of the surrounding structure for the battery module 30.

[0052] In the battery mounting structure of this embodiment, as shown in Figures 1 and 4, the side modules 16 are arranged to protrude upward relative to the center module 15. In other words, the height position of the side modules 16 is offset (shifted) upward relative to the center module 15. Conversely, the center module 15 is arranged to protrude downward relative to the side modules 16. In other words, the height position of the center module 15 is offset downward relative to the side modules 16. Such an offset arrangement in the vertical direction can be said to be an arrangement in which the position of the side modules 16 among the multiple (e.g., six) battery modules 30 (31 to 36) is raised, or can be said to be an arrangement in which the side modules 16 protrude upward more than the center module 15.

[0053] The side modules 16 illustrated here are arranged in a position where they partially overlap the center module 15 in the vertical direction when viewed from the vehicle width direction. This arrangement can be said to be an arrangement in which all of the battery modules 30 overlap at least a portion of the vertical area, and can also be said to be an arrangement in which the side modules 16 are not elevated too high above the entire center module 15. In addition, the center modules 15 are arranged at equal height positions. The side modules 16 are also arranged at equal height positions.

[0054] With respect to the battery module 30 in which the relative height positions of the center module 15 and side modules 16 are set as described above, the height positions relative to the side members 7 among the peripheral structures of the battery pack 10 will be described with reference to Figure 1. The lower part (part) of the center module 15 is disposed at a height position that overlaps with the side members 7 when viewed from the vehicle width direction. On the other hand, the side modules 16 are disposed at a height position higher than the side members 7 without overlapping with them when viewed from the vehicle width direction. This arrangement of the battery module 30 relative to the side members 7 can be said to be an arrangement in which the center module 15 is fitted between the side members 7, and can also be said to be a recessed arrangement in which the side modules 16 are set back upward to avoid interference with the side members 7 (peripheral structures).

[0055] Regarding the height position of the lower end surfaces 30L of the battery modules 30 relative to the upper ends 7U of the side members 7, the lower end surface 30L of the center module 15 (only one location is marked with a reference symbol in FIG. 1 ) is located below the upper ends 7U of the side members 7. Meanwhile, the lower end surfaces 30L of the side modules 16 are located above the upper ends 7U of the side members 7.

[0056] The side lower space 20S formed below the side module 16, which is disposed offset upward as described above, has a larger vertical dimension than the center lower space 20C formed below the center module 15. In other words, the vertical dimension of the center lower space 20C is smaller than that of the side lower space 20S. The lower part of the side lower space 20S is in communication with the center lower space 20C.

[0057] The lower end of the side lower space 20S is defined by a slope surface 51X that is located downward (inclined downward) on at least a portion of the side inner bottom surface 51S toward the center in the vehicle width direction. In other words, the slope surface 51X is a planar portion that slopes downward from the outer side to the inner side in the vehicle width direction.

[0058] Furthermore, as shown in FIG. 2 , the side modules 16 provided in the battery mounting structure exemplified in this embodiment are disposed so as to protrude forward relative to the center module 15. In other words, this arrangement means that the position of the side modules 16 in the front-to-rear direction is offset forward relative to the center module 15. Conversely, the center module 15 is disposed so as to protrude rearward relative to the side modules 16. In other words, this arrangement means that the position of the center module 15 in the front-to-rear direction is offset rearward relative to the side modules 16. This offset arrangement in the front-to-rear direction can also be described as an arrangement in which the side modules 16 are positioned forward among the multiple (e.g., six) battery modules 30 (31 to 36).

[0059] A rear wall portion 61 is provided on the side wall portion 60 of the battery pack case 20, extending rearward from the battery module 30, along the outer shape of the battery module 30, with the relative longitudinal positions of the center module 15 and the side modules 16 set as described above. Specifically, a portion 61S (hereinafter referred to as a "side portion") of the rear wall portion 61 extending rearward from the side module 16 is positioned further forward than a portion 61C (hereinafter referred to as a "center portion") extending rearward from the center module 15. In other words, a central portion 61C of the rear wall portion 61, which is located in the center of the vehicle width direction, is formed in a shape that protrudes rearward.

[0060] The side portions 61S extend to the rear and left and right corners of the tray 21 of the battery pack case 20. Therefore, the rear and left and right corners of the tray 21 are positioned shifted forward. The front wall portion 62 of the side wall portion 60, which is erected in front of the battery module 30, extends in a flat plate shape along the vehicle width direction. The junction box 43 is housed between the center module 15 and the front wall portion 62, which does not have any concave or convex shapes in the front and rear directions. In other words, the side modules 16 are positioned offset forward without changing the layout of the junction box 43, which is positioned in front of the center module 15.

[0061] [1-3. Battery Pack Air Intake Structure] The following describes in detail the battery pack air intake structure that takes in cooling air into the internal space 20A of the battery pack case 20. In a structure like this embodiment, in which air from the vehicle interior is taken into the battery pack case 20 to cool the battery modules 30, the air intake 45A serving as the cooling air intake must be open to the vehicle interior. However, if the air intake that takes in cooling air is directly exposed to the vehicle interior (hereinafter referred to as "Comparative Structure 2"), there is a risk that foreign objects from the vehicle interior may enter the internal space of the battery pack case. For example, in Comparative Structure 2, in which the air intake formed on the top surface of the battery pack case is exposed to the vehicle interior, there is a risk that small objects dropped by an occupant may roll into the air intake, or that a drink spilled by an occupant may run down the seat and enter the air intake.

[0062] Therefore, the battery pack air intake structure of this embodiment prevents the air intake port 45A, which takes in cooling air, from being exposed to the vehicle interior, thereby preventing foreign objects from entering the internal space 20A of the battery pack case 20. This will be described in detail below with reference to FIGS. 5 and 6 . FIG. 5 is a cross-sectional view of the main part of the air intake port 45A located on the left side of the vehicle, seen from the front of the vehicle, showing the surrounding structure of the air intake port 45A. FIG. 6 shows an air intake port cover 70 that covers the air intake port 45A from above. In the description using FIGS. 5 and 6 , the "right side" refers to the inside in the vehicle width direction, and the "left side" refers to the outside in the vehicle width direction. In this embodiment, a pair of left and right air intake ducts 45 are provided, so the surrounding structure of the air intake port 45A on the right side of the vehicle and the air intake port cover 70 (not shown) are similar to the configurations described below (bilaterally symmetrical).

[0063] As shown in Fig. 5 , the battery pack air intake structure of this embodiment includes an air intake cover 70 that covers the air intake 45A from above. The air intake cover 70 is disposed above and spaced apart from the air intake 45A, and a horizontal gap 47 is interposed between the air intake cover 70 and the upper surface 20F of the battery pack case 20. That is, the cover lower surface 70L of the air intake cover 70 faces the upper surface 20F and the air intake 45A via the gap 47. The upper surface 70J of the air intake cover 70 (hereinafter referred to as the "cover upper surface") is exposed to the vehicle interior 1.

[0064] The gap 47 communicates with the vehicle interior space via the air intake 71. That is, the air intake cover 70 not only forms the air intake 71, but also forms the gap 47 with the upper surface 20F of the battery pack case 20 (which may also be referred to as the "case upper surface"). Here, three air intakes 71A, 71B, and 71C are shown as examples of the air intakes 71. Of the three air intakes 71A, 71B, and 71C, one is a right air intake 71A facing to the right of the vehicle, another is a rear air intake 71B facing to the left of the vehicle, and the remaining one is an upper air intake 71C facing upward.

[0065] The right intake port 71A and the left intake port 71B are defined at their upper edges by the right and left edges, respectively, of the intake port cover 70, and are provided horizontally (in a direction different from the direction of the intake port 45A). To explain the arrangement of the right intake port 71A and the left intake port 71B based on the position of the intake port 45A, the right intake port 71A is formed on the right side of the intake port 45A (one side in a predetermined direction), and the left intake port 71B is formed on the left side of the intake port 45A (the other side in the predetermined direction).

[0066] As described above, the intake port cover 70 forms the right intake port 71A and the left intake port 71B on the right and left sides of the intake port 45A, respectively, and has an upper intake port 71C formed in an area that does not overlap with the intake port 45A in a top view. The upper intake port 71C illustrated here is provided on the right side of the intake port 45A and is located near the right intake port 71A. Figure 6 shows an example of the upper intake port 71C with a mesh member 72 stretched therethrough.

[0067] The right air intake 71A and the left air intake 71B do not have a mesh member 72 like the upper air intake 71C, and are simply openings. The three air intakes 71A, 71B, and 71C are arranged at different distances (separation distances) from the air intake 45A. FIG. 5 illustrates an example in which the right air intake 71A is farthest from the air intake 45A and the left air intake 71B is closest. The three air intakes 71A, 71B, and 71C are arranged away from the edge 4E (opening edge) of the carpet 4. The edge 4E of the carpet 4 is a location where warm air heated by, for example, the vehicle's exhaust system can leak out.

[0068] Incidentally, if liquid is spilled on the intake port cover 70, for example, the liquid may pool on the cover upper surface 70J depending on the shape of the cover upper surface 70J of the intake port cover 70. Furthermore, if liquid spills on the cover upper surface 70J and seeps in through the air intake 71, the seeping liquid may be easily guided along the cover lower surface 70L toward above the intake port 45A depending on the shape of the cover lower surface 70L of the intake port cover 70. In particular, if the cover lower surface 70L is configured to be positioned lower as it approaches the intake port 45A from the air intake 71, the seeping water may be guided by gravity along the cover lower surface 70L toward above the intake port 45A, resulting in the water seeping into the intake port 45A.

[0069] Therefore, the cover upper surface 70J and the cover lower surface 70L are inclined to properly handle liquid that may adhere to the intake port cover 70. The cover upper surface 70J is inclined so as to be positioned downward toward the air intake 71. The cover upper surface 70J illustrated here is in a roof shape (a downwardly inclined eave shape) that is positioned lower (downwardly inclined) as it approaches each of the left and right edges.

[0070] The cover lower surface 70L is provided with an upwardly sloping portion 70G that is positioned upward (inclined upward) as it approaches the air intake 45A from the air intake 71. Figure 5 shows an example in which an upwardly sloping portion 70G that is positioned upward (inclined upward) is provided as it approaches the air intake 45A from each of the right air intake 71A and the left air intake 71B.

[0071] The illustrated air intake cover 70 extends from above to an area that covers the metal sheet edge 3E, which is the edge portion of the panel member 3 that is provided around the air intake 45A. In other words, the air intake cover 70 extends from the air intake 45A to the metal sheet edge 3E of the panel member 3 when viewed from above the vehicle. However, the air intake cover 70 does not overlap the edge 4E of the carpet 4 when viewed from above.

[0072] The battery pack air intake structure of this embodiment includes not only air intake cover 70 but also rib 80 that structurally prevents foreign matter that has gotten into gap 47 from entering air intake 45A. Rib 80 stands upright within gap 47 from top surface 20F of battery pack case 20. Rib 80 is provided with a gap (a gap that connects air intake 71 and air intake 45A) between air intake cover 70 (i.e., not in contact with underside 70L of air intake cover 70).

[0073] Although not shown, as another form of rib, a rib may be erected from the intake port cover 70 into the gap 47. In this case, the rib may be provided with a gap from the top surface 20F of the battery pack case 20. The former rib 80 (the rib 80 erected from the top surface 20F) and the latter rib (the rib erected from the intake port cover 70) may be provided side by side. Furthermore, the rib may be provided with a gap that at least connects the air intake 71 and the intake port 45A, and may be erected from both the top surface 20F of the battery pack case 20 and the intake port cover 70.

[0074] In the configuration illustrated in this embodiment, the air intake port 45A, the rib 80, and the air intake 71 are arranged side by side in the vehicle width direction. The illustrated rib 80 is formed as a peripheral wall that surrounds the periphery of the air intake port 45A in a top view, as shown in Fig. 6. The ribs 80 that stand upright and surround the periphery of the air intake port 45A can be said to be provided on both sides of the air intake port 45A, or in other words, the entire area of ​​the rib 80 overlaps with the air intake port 45A in the front-rear direction.

[0075] The rib 80 includes a right rib 81 (first rib) located on the right side of the intake port 45A, and a left rib 82 (second rib) located on the left side of the intake port 45A. These ribs 81, 82 have different distances from the air intake port 71. Specifically, the distance L1 between the right rib 81 and the right intake port 71A is longer than the distance L2 between the left rib 82 and the left intake port 71B (satisfying the inequality "L1 > L2").

[0076] The longer the ribs 81, 82 are in the vertical direction, the more effective they are in preventing foreign matter from entering the vehicle, but this structurally blocks the airflow path from the vehicle interior, which reduces the efficiency of cooling air intake. Therefore, the dimensions and arrangement of the ribs 81, 82 are set to achieve both the effect of preventing foreign matter from entering the vehicle and the effect of preventing a reduction in the efficiency of cooling air intake.

[0077] As shown in FIG. 5 , the heights G1 and G2 of the ribs 81 and 82 from the adjacent surfaces 9A and 9B adjacent to the ribs 81 and 82 are set according to the distances L1 and L2 from the air intakes 71A and 71B adjacent to the ribs 81 and 82. Specifically, a first height G1 from the right adjacent surface 9A (first adjacent surface) adjacent to the right side of the right rib 81 to the upper end 81U of the right rib 81 is smaller than a second height G2 from the left adjacent surface 9B (second adjacent surface) adjacent to the left side of the left rib 82 to the upper end 82U of the left rib 82. That is, the inequality "G1 < G2" is satisfied, and the heights G1 and G2 (i.e., "gaps") from the adjacent surfaces 9A and 9B adjacent to the opposite side of the ribs 81 and 82 from the intake port 45A are smaller as the distances L1 and L2 increase. That is, the gap of the right rib 81, which is positioned further back than the other ribs 81 and 82, is reduced. In this embodiment, the right adjacent surface 9A is the top surface of another panel member to which the panel member 3 is fixed, and the left adjacent surface 9B is the top surface 20F of the battery pack case 20.

[0078] Furthermore, the height positions of the upper ends 81U, 82U of the ribs 81, 82 (shown by dashed lines in FIG. 5 ) are approximately equal to the height positions of the upper ends of the air intakes 71A, 71B (shown by dashed lines in FIG. 5 ). That is, the ribs 81, 82 are erected on each path that leads straight from each air intake 71A, 71B to the intake port 45A. Therefore, the air taken in through the air intakes 71A, 71B snakes above the ribs 81, 82 before flowing into the intake port 45A, and a non-linear, complex path (a so-called "labyrinth structure") is formed by the ribs 81, 82 and the intake port cover 70.

[0079] To increase the efficiency of cooling air intake, the height positions of the upper ends 81U, 82U of the ribs 81, 82 can be set lower than the height positions of the upper ends of the air intakes 71A, 71B. Conversely, to more reliably prevent foreign matter from entering, the height positions of the upper ends 81U, 82U of the ribs 81, 82 can be set higher than the height positions of the upper ends of the air intakes 71A, 71B. In addition, from the perspective of ensuring the efficiency of cooling air intake, the rib 80 is provided in a region of the gap 47 excluding the space above the intake port 45A.

[0080] [1-4. Battery Module Cooling Structure] The following describes in detail the battery module cooling structure that cools the battery modules 30. In a structure in which cooling air is introduced into the lower space 20L below the battery modules 30, as in the present embodiment, if the lower space is not partitioned (hereinafter referred to as "Comparative Structure 3"), there is a risk that areas in the lower space will be poorly circulated by the cooling air or that an excessive amount of cooling air will be supplied. Therefore, Comparative Structure 3 may not be able to cool the multiple battery modules in a balanced manner.

[0081] Therefore, the battery module cooling structure of this embodiment partitions the lower space 20L into which cooling air is introduced, thereby achieving well-balanced cooling of the battery modules 30. As shown in Figures 7 and 8, the battery module cooling structure of this embodiment is provided with a plurality of partitions 90 that partially partition the lower space 20L and extend in the front-to-rear direction, and the length of the partitions 90 extending in the front-to-rear direction is determined by the locations of the partitions 90.

[0082] The partitions 90 are disposed between adjacent battery modules 30. Specifically, at least a portion of each partition 90 is disposed between two adjacent battery modules 30 in the vehicle width direction in a plan view, and as shown in FIG. 8 , the partitions 90 extend upward from the inner bottom surface 51 of the tray 21 (battery pack case 20). As shown in FIG. 8 , the bottom wall 50 of the tray 21 may be curved to extend upward from the inner bottom surface 51, or the lower surface of the bottom wall 50 may be flush with the inner bottom surface 51. The partitions 90 may be integrated with the battery pack case 20 or may be provided separately from the battery pack case 20. Each partition 90 illustrated here has a constant or approximately constant shape in its widthwise dimension regardless of its longitudinal position. The upper ends of the partitions 90 are in surface contact with the lower end surfaces 30L of the battery modules 30 on both sides of the partition 90. This separates the lower space 20L.

[0083] If the spaces below each battery module 30 and above the inner bottom surface 51 are referred to as "small spaces," and the lower space 20L is referred to as a "large space" in which the small spaces are arranged in the vehicle width direction, the large space is divided into small spaces by the partitions 90 while the small spaces remain partially connected to each other. The size of the area in which the small spaces partially communicate with each other is adjusted by the extension dimension (i.e., the dimension in the front-to-rear direction) of the partitions 90.

[0084] 7 illustrates an example of a battery module cooling structure having six battery modules 30 and five partitions 90. The five partitions 90 are provided, in order from left to right, with a first partition 91, a second partition 92, a third partition 93, a fourth partition 94, and a fifth partition 95. Of these five partitions 90, the third partition 93 is provided in the center in the vehicle width direction, the first partition 91 and the fifth partition 95 are provided symmetrically, and the second partition 92 and the fourth partition 94 are provided symmetrically.

[0085] The first partition 91 is disposed between the first battery module 31 and the second battery module 32 in a plan view. The second partition 92 is disposed between the second battery module 32 and the third battery module 33 in a plan view. Similarly, the third partition 93 is disposed between the third battery module 33 and the fourth battery module 34 in a plan view. The fourth partition 94 is disposed between the fourth battery module 34 and the fifth battery module 35 in a plan view. The fifth partition 95 is disposed between the fifth battery module 35 and the sixth battery module 36 in a plan view.

[0086] Explaining the arrangement of the partitions 90 based on the inlet 45B and the outlet 46C (shown by thick dashed lines in FIG. 7 ), the third partition 93 is arranged closer to the outlet 46C than the inlet 45B in the vehicle width direction. Next, the second partition 92 and the fourth partition 94 are arranged closer to the outlet 46C than the inlet 45B. The first partition 91 and the fifth partition 95 are arranged farthest from the outlet 46C than the inlet 45B.

[0087] The distance from the front end 90F of the partition 90 (one end closer to the inlet 45B in the second direction) to the front end of the lower space 20L (internal space 20A) (one end closer to the inlet 45B in the second direction) is longer for partitions 90 that are located closer to the inlet 45B than the outlet 46C in the vehicle width direction. By setting the length of the partitions 90 in this way, the area connecting the small spaces below each battery module 30 and above the inner bottom surface 51 becomes smaller the closer the area connecting the small spaces is to the outlet 46C. In other words, the area connecting the small spaces becomes larger the closer to the inlet 45B.

[0088] The five partitions 90 illustrated here have their ends, one of which is closer to the exhaust outlet 46C than the inlet 45B, aligned in the front-rear direction. Specifically, the rear ends 90B of the partitions 90 (one of which is closer to the exhaust outlet 46C than the inlet 45B) are positioned at equal front-rear directions. For example, the rear end 90B of the partitions 90 is disposed in contact with the rear end of the lower space 20L (the end closer to the exhaust outlet 46C in the second direction). Furthermore, the partitions 90 that are disposed closer to the inlet 45B than the exhaust outlet 46C in the vehicle width direction have shorter front-rear dimensions.

[0089] As illustrated in this embodiment, when the exhaust port 46C is provided at the center between the inlet 45B located on the left side of the lower space 20L in the vehicle width direction and the inlet 45B located on the right side of the lower space 20L in the vehicle width direction, the partitions 90 are configured to have a longer front-rear dimension as they are positioned closer to the center in the vehicle width direction. In other words, the partitions 90 are configured to have a shorter front-rear dimension as they are positioned further outward in the vehicle width direction. That is, the front ends 90F of the partitions 90 are located further rearward as they are positioned further outward in the vehicle width direction. Specifically, of the partitions 90, the third partition 93 has the longest front-rear dimension, and the second partition 92 and the fourth partition 94 have shorter front-rear dimensions than the third partition 93. Furthermore, the first partition 91 and the fifth partition 95 have shorter front-rear dimensions than the second partition 92 and the fourth partition 94.

[0090] The first partition 91 and the fifth partition 95 extend in the front-rear direction with a dimension shorter than the front-rear dimension of each battery module 30. In contrast, the second partition 92, the fourth partition 94, and the third partition 93 extend in the front-rear direction with a dimension longer than the front-rear dimension of each battery module 30. Based on the length of the partitions 90 relative to the front-rear dimension of the battery module 30, the first partition 91 and the fifth partition 95 may be referred to as "short partitions," and the second partition 92, the fourth partition 94, and the third partition 93 may be referred to as "long partitions."

[0091] In addition to the partitions 90, the battery module cooling structure exemplified in this embodiment is provided with a structure for ensuring appropriate circulation of cooling air in the lower space 20L and the upper space 20U in order to distribute air evenly to each battery cell 30C (see FIG. 9 ) in the battery module 30 and equalize the temperature of each battery cell 30C. Note that the side closer to the inlet 45B than the outlet 46C in the front-to-rear direction can be said to be the upstream side in the cooling air flow direction, which is the front side in this embodiment. The side closer to the outlet 46C than the inlet 45B in the front-to-rear direction can be said to be the downstream side in the cooling air flow direction, which is the rear side in this embodiment.

[0092] If the inner bottom surface of the tray were flat, cooling air would flow more easily through the lower space closer to the exhaust port, making it less likely for cooling air to stagnate in the upstream region of the lower space closer to the inlet. If cooling air does not stagnate sufficiently in the upstream region of the lower space, the lower portion of the battery module closer to the inlet port than the exhaust port may not be able to exchange heat sufficiently with the cooling air. Therefore, there is room for improvement in cooling the lower portion of the battery module closer to the inlet port than the exhaust port.

[0093] To address this issue, the battery module cooling structure exemplified in this embodiment has a step on the inner bottom surface 51 that defines the lower end of the lower space 20L, thereby ensuring reliable cooling of the portion of the lower part of the battery module 30 that is closer to the inlet than the outlet. Specifically, as shown in Fig. 9, the battery pack case 20 has a lower step portion 52 on the inner bottom surface 51 that is higher on the downstream side in the direction of cooling air flow than on the upstream side.

[0094] The lower step portion 52 is formed between an upstream bottom surface 53 located on the front side of the inner bottom surface 51 and a downstream bottom surface 54 located on the rear side. The upstream bottom surface 53 is located lower than the downstream bottom surface 54. In other words, the downstream bottom surface 54 is closer to the horizontal bottom surface 30L of the battery module 30 than the upstream bottom surface 53. Considering that the distances between the bottom surfaces 53 and 54 and the bottom surface 30L of the battery module 30 are different, the lower step portion 52 can also be said to have a structure that narrows the downstream side of the direction in which cooling air flows in the lower space 20L.

[0095] Furthermore, if the surface defining the upper end of the internal space (hereinafter referred to as the "inner top surface") were flat, cooling air would be more likely to flow to the upstream region of the upper space closer to the inlet. If cooling air were to be unevenly supplied to the upstream region of the upper space, the upper portion of the battery module closer to the inlet than the outlet might be overcooled. Therefore, there is room for improvement in preventing excessive cooling of the upper portion of the battery module closer to the inlet than the outlet.

[0096] To address this issue, the battery module cooling structure exemplified in this embodiment has a step on the inner top surface 23 that defines the upper end of the upper space 20U (internal space 20A), thereby preventing excessive cooling of the upper portion of the battery module 30 that is closer to the inlet than the outlet. The inner top surface 23 has an upper step 24 that is positioned lower on the upstream side than the downstream side in the direction of cooling air flow.

[0097] The upper step portion 24 is formed between a downstream top surface 26 located on the rear side of the inner top surface 23 and an upstream top surface 27 located on the front side. The upstream top surface 27 is located lower than the downstream top surface 26. That is, the upstream top surface 27 is closer to the horizontal upper end surface 30U of the battery module 30 than the downstream top surface 26. Considering that the distances between the top surfaces 26 and 27 and the upper end surface 30U of the battery module 30 are different, the upper step portion 24 can also be said to have a structure that narrows the upstream side in the direction in which cooling air flows in the upper space 20U. The upper step portion 24 may be formed in the battery pack case 20 or may be provided in a component other than the battery pack case 20.

[0098] In the upper space 20U, as described above, cooling air tends to flow more easily into the space in the front upstream region in the fore-and-aft direction (i.e., the side closer to the inlet 45B) regardless of the position in the vehicle width direction. Because of this tendency, it is preferable that the upper step portion 24 be disposed on the inner top surface 23 that defines the upper space 20U above all of the battery modules 30. However, the upper step portion 24 may also be disposed on the inner top surface 23 that defines the upper space 20U above only some of the battery modules 30.

[0099] In addition, cooling air flows easily through the upper space 20U near the outlet 46C, which may increase the flow rate of the cooling air. If excessive cooling air is supplied to the space near the outlet 46C, the rear portion of the upper part of the battery module 30 (the side closer to the outlet 46C than the inlet 45B) may be excessively cooled, resulting in a localized increase in cooling performance.

[0100] Therefore, the battery module cooling structure exemplified in this embodiment is provided with a baffle plate 99 that suppresses the flow rate and supply of cooling air in the space of the upper space 20U that is closer to the exhaust port 46C. The baffle plate 99 is disposed below the downstream top surface 26 and above the battery modules 30 in the upper space 20U, and is a component that obstructs the flow of cooling air from below to above.

[0101] In the upper space 20U, the cooling air tends to flow more easily toward the rear (closer to the outlet 46C in the front-to-rear direction) of the space toward the center in the vehicle width direction (closer to the outlet 46C in the vehicle width direction). Due to this tendency, it is preferable to dispose the baffle plate 99 in the upper space 20U above the third battery module 33 and the fourth battery module 34 (see FIGS. 2 and 7).

[0102] [2. Actions and Effects] Since this embodiment is configured as described above, the following actions and effects can be obtained.

[0103] [2-1. Battery Mounting Structure] (1A) In the battery mounting structure of this embodiment, the side modules 16 are disposed so as to protrude upward relative to the center module 15. Therefore, when applying the above-described battery mounting structure to an existing structure that includes side members 7, an exhaust pipe 8, and the like, it becomes easier to avoid interference between the existing structure and the side modules 16 and center module 15. For example, the center module 15 fits between the side members 7, making it possible to mount the battery module 30 below the seat 2. In this way, the above-described battery mounting structure allows the battery module 30 to be mounted without modifying the existing structure. This ensures flexibility in the layout of the surrounding structure around the battery module 30.

[0104] (2A) In this embodiment, the side modules 16 are disposed in a position where they partially overlap the center module 15 in the vertical direction when viewed in the vehicle width direction. This prevents the vertical dimension of the battery pack case 20 from increasing compared to an arrangement in which the side modules 16 are positioned higher than the entire center module 15. In this way, the ability to prevent the battery pack case 20 from becoming larger also ensures flexibility in the layout of the surrounding structure for the battery module 30.

[0105] (3A) The center modules 15 are arranged at equal height positions, and the side modules 16 are also arranged at equal height positions. As a result, a space with a large bottom area where multiple top surfaces of the center modules 15 are lined up can be secured above the center modules 15 in the internal space 20A of the battery pack case 20. This space can be utilized as a space capable of accommodating electrical components such as the BMU 40 and transformer 41. In addition, since the center modules 15 are arranged at equal height positions, this contributes to improving the ease of routing the harnesses 42 connected to each center module 15. Furthermore, since the side modules 16 are also arranged at equal height positions, the layout of the battery modules 30 can be prevented from becoming complicated.

[0106] (4A) Of the six battery modules 30, two side modules 16 are located on the outermost sides of the vehicle width. Therefore, compared to a battery mounting structure with more than two side modules 16, it is possible to both prevent the vehicle's center of gravity from becoming high and ensure flexibility in the layout of the surrounding structure for the battery modules 30.

[0107] (5A) A battery pack case 20 is mounted below the seat 2, and a side module 16 is disposed in the internal space 20A of the battery pack case 20, offset forward in the fore-and-aft direction relative to the center module 15. Therefore, the side portion 61S erected on the rear side of the side module 16 can be disposed forward of the central portion 61C erected on the rear side of the center module 15 in the battery pack case 20. This improves the ease of entry and exit for passengers getting in and out of seats immediately behind the seat 2. For example, it improves the legroom for passengers getting in the second-row rear seats relative to the driver's seat or passenger seat 2. Furthermore, it also makes it easier for passengers sitting in seats adjacent to the rear of the seat 2 (i.e., while riding) to stretch their legs, improving the livability of the passenger compartment 1.

[0108] (6A) Because the center lower space 20C is smaller than the side lower space 20S, cooling air is more likely to stagnate in the side lower space 20S than in the center lower space 20C. This allows the cooling air in the side lower space 20S to stagnate before flowing into the center lower space 20C, allowing the entire battery module 30 to be cooled in a balanced manner.

[0109] (7A) The lower end of the side lower space 20S is defined by a slope surface 51X that is positioned downward toward the center in the vehicle width direction on at least a portion of the side inner bottom surface 51S. This ensures a volume of the side lower space 20S in which cooling air can remain, while suppressing interference with surrounding structures due to the side lower space 20S expanding toward the end in the vehicle width direction.

[0110] (8A) In addition, because the side modules 16 are positioned with their height positions offset upward relative to the center module 15, the side modules 16 can be positioned at a distance from the exhaust pipe 8, which reduces heating of the side modules 16 due to radiant heat from the exhaust pipe 8. In this way, reducing the heat received by the side modules 16 from the exhaust pipe 8 contributes to improving the cooling performance of the side modules 16.

[0111] [2-2. Battery Pack Air Intake Structure] (1B) According to the battery pack air intake structure of this embodiment, the air intake 45A is covered with the air intake cover 70, which structurally prevents foreign objects from entering the air intake 45A from above. Furthermore, by providing a rib 80 in the gap 47 between the air intake 71 and the air intake 45A, even if a foreign object enters the gap 47 from the air intake 71, the rib 80 structurally prevents the foreign object from entering the air intake 45A. This prevents foreign objects from entering the internal space 20A of the battery pack case 20. In this way, the intrusion of foreign objects is prevented, and air from the vehicle interior 1 can be taken into the air intake 45A through the gap connecting the air intake 71 and the air intake 45A.

[0112] (2B) The rib 80 is provided with a gap from the intake port cover 70. Therefore, air from the vehicle interior 1 can be taken into the intake port 45A through the gap between the rib 80 and the intake port cover 70, which connects the air intake 71 and the intake port 45A, thereby ensuring the intake efficiency of the intake port 45A.

[0113] (3B) The rib 80 is erected from the upper surface 20F of the battery pack case 20 into the gap 47. This structurally prevents foreign matter that rolls or is pushed along the upper surface 20F of the battery pack case 20 from entering the air intake 45A, improving the effect of preventing foreign matter from entering.

[0114] (4B) In the above-described embodiment, the upper ends 81U, 82U of the ribs 81, 82 are positioned at approximately the same height as the upper ends of the air intakes 7A, 7B. The ribs 81, 82 are neither too high nor too low, which makes it possible to both prevent foreign matter from entering and prevent a decrease in the efficiency of cooling air intake.

[0115] (5B) In the above-described embodiment, the right intake 71A and upper intake 71C are provided on the right side of the intake port 45A, and the left intake 71B is provided on the left side of the intake port 45A. Ribs 81 and 82 are provided on both the right and left sides of the intake port 45A. Therefore, air is taken in through the three (multiple) air intakes 71A, 71B, and 71C, ensuring efficient intake of cooling air. Furthermore, the right rib 81 (the rib 81 on the inner side in the vehicle width direction) can prevent foreign matter from entering through the right intake 71A and upper intake 71C on the right side (inner side in the vehicle width direction) of the intake port 45A, and the left rib 82 (the rib 82 on the outer side in the vehicle width direction) can prevent foreign matter from entering through the left intake 71B on the left side (outer side in the vehicle width direction) of the intake port 45A.

[0116] (6B) Since the entire area of ​​the rib 80 overlaps with the intake port 45A in the front-to-rear direction, the intrusion of foreign matter into the intake port 45A can be structurally prevented in the entire area in the front-to-rear direction. (7B) Furthermore, since the rib 80 is erected so as to surround the periphery of the intake port 45A, the intrusion of foreign matter into the intake port 45A can be structurally prevented in all directions.

[0117] (8B) The cover top surface 70J of the air intake cover 70 is inclined downward toward the air intake 71. Therefore, even if liquid spills on the cover top surface 70J, the liquid flows down the cover top surface 70J toward the air intake 71. Therefore, the shape (structure) of the cover top surface 70J can prevent liquid from accumulating on the cover top surface 70J. This cover top surface 70J can also prevent dust from accumulating on the cover top surface 70J.

[0118] (9B) Furthermore, the cover underside 70L of the intake port cover 70 is provided with an upwardly sloping portion 70G that rises upward as it approaches the intake port 45A from the air intake 71. Therefore, the shape (structure) of the cover underside 70L can prevent liquid from flowing down the cover underside 70L and entering the intake port 45A.

[0119] (10B) In the ribs 81, 82 of the above-described embodiment, height dimensions G1, G2 from adjacent surfaces 9A, 9B adjacent to the ribs 81, 82 on the opposite side of the intake port 45A to the upper ends 81U, 82U of the ribs 81, 82 are set smaller when the separation distance L1, L2 is longer. In this way, by reducing the height dimension of one rib 81 that is recessed relative to the other rib 82, it is possible to suppress a decrease in the efficiency of intake of cooling air while suppressing the intrusion of foreign matter into the intake port 45A.

[0120] (11B) The air intake cover 70 described above extends to an area that covers from above the metal sheet edge 3E of the panel member 3. Because the metal sheet edge 3E is covered by the air intake cover 70 in this manner, even if an occupant in the vehicle interior 1 drops something and searches for it by hand under the seat 2, the occupant can be structurally prevented from touching the metal sheet edge 3E, thereby improving the safety of the occupant.

[0121] (12B) The air intake cover 70 described above has an upward-facing upper intake 71C in an area that does not overlap with the air intake 45A in a top view. Therefore, even if this battery pack air intake structure is applied to a vehicle with a peripheral configuration in which warm air that may leak from the edge 4E (opening end) of the carpet 4 is taken in through the horizontally facing right intake 71A or left intake 71B, cool air can be taken in through the upward-facing upper intake 71C. This prevents warm air from being taken into the battery pack case 20, contributing to improved cooling efficiency.

[0122] (13B) According to the upper intake 71C on which the mesh member 72 described above is stretched, even if the upper intake 71C is provided facing upward, the mesh member 72 can capture foreign matter, thereby preventing foreign matter from entering through the upper intake 71C.

[0123] [2-3. Battery Module Cooling Structure] (1C) According to the battery module cooling structure of this embodiment, the distance from the front end 90F of the partition 90 to the front end of the lower space 20L is longer for partitions 90 located closer to the inlet 45B than the outlet 46C in the vehicle width direction. This makes it easier for cooling air to stagnate in the region of the lower space 20L where the inlet 45B is located relative to the outlet 46C, and allows cooling air to be distributed evenly from this region to the region of the lower space 20L where the outlet 46C is located relative to the inlet 45B. By optimizing the extension dimension of the partition 90 in this way, cooling air is supplied to the lower space 20L in a balanced manner. This allows for balanced cooling of the multiple battery modules 30.

[0124] In the embodiment illustrated in the present invention, the rear ends 90B of the partitions 90 are provided at equal positions in the front-rear direction, and the partitions 90 that are positioned closer to the inlet 45B in the vehicle width direction than the outlet 46C have shorter front-rear dimensions. With partitions 90 positioned and sized in this way, the length of the partition 90 extending in the front-rear direction corresponds to the size of the area in front of the partition 90 through which cooling air communicates in the vehicle width direction. Therefore, simply by setting the length of the partition 90 extending in the front-rear direction, the size of the area in the lower space 20L through which cooling air communicates in the vehicle width direction in front of the partition 90 can be set.

[0125] (2C) If the lower space extends to the left or right of the inlet and the exhaust outlet is located closer to the center of the vehicle width than the inlet, the cooling air introduced from the inlet would not be able to reach the space in the lower space that extends laterally outward from the inlet (opposite the exhaust outlet). In contrast, with the battery module cooling structure described above, the inlet 45B is provided at the left or right end of the lower space 20L, which makes it easier for the cooling air in the lower space 20L to reach the entire vehicle width, thereby enabling balanced cooling of the multiple battery modules 30.

[0126] (3C) In this embodiment, the lower space 20L has an inlet 45B at each of the left and right ends, and an outlet 46C is provided in the center between the inlet 45B located on the left side and the inlet 45B located on the right side. Therefore, the partitions 90 located closer to the center in the vehicle width direction are configured to have longer longitudinal dimensions. Therefore, the partitions 90 located in the center in the vehicle width direction, including the third partition 93, can prevent the cooling air introduced from the inlet 45B at the left end and the cooling air introduced from the inlet 45B at the right end from mixing within the lower space 20L. This also allows for balanced cooling of the multiple battery modules 30.

[0127] (4C) The first partition 91 and the fifth partition 95 (i.e., "short partitions"), which extend in the front-rear direction and are shorter than the battery modules 30, can further promote retention of cooling air in the region of the lower space 20L on the outer side in the vehicle width direction (the inlet 45B side). The second partition 92, the fourth partition 94, and the third partition 93 (i.e., "long partitions"), which extend in the front-rear direction and are longer than the battery modules 30, can cool the entire battery module 30 in the region of the lower space 20L on the central side in the vehicle width direction (the outlet 46C side). This contributes to improving the cooling performance of the battery module 30.

[0128] (5C) The lower step 52 formed between the downstream bottom surface 54 and the upstream bottom surface 53 narrows the rear space (closer to the exhaust port 46C) of the lower space 20L compared to the front space (closer to the inlet 45B). This prevents excessive flow of cooling air into the rear space of the lower space 20L, while ensuring sufficient flow of cooling air into the front space of the lower space 20L. This prevents excessive cooling of the rear portion of the lower part of the battery module 30, while allowing sufficient cooling of the front portion of the lower part of the battery module 30. In this way, the entire battery module 30 can be cooled in a balanced manner.

[0129] (6C) The upper step 24 formed between the downstream top surface 26 and the upstream top surface 27 narrows the space on the front side (the side closer to the inlet 45B) of the upper space 20U, thereby suppressing excessive flow of cooling air into the front space of the upper space 20U and suppressing excessive cooling of the front portion of the upper part of the battery module 30. In this way, the entire battery module 30 can be cooled in a balanced manner.

[0130] (7C) In addition, because the baffle plate 99, which obstructs the flow of cooling air from below to above, extends below the downstream top surface 26 and above the battery modules 30, the baffle plate 99 obstructs the flow of cooling air in the rear space of the upper space 20U to the exhaust port 46C. As a result, the cooling air remains in the rear space of the upper space 20U, ensuring that the rear portion of the upper part of the battery module 30 is cooled reliably. This also allows for balanced cooling of the entire battery module 30.

[0131] (8C) Furthermore, because the center lower space 20C is smaller than the side lower space 20S, cooling air tends to accumulate in the side lower space 20S more easily than in the center lower space 20C. This allows the cooling air in the side lower space 20S to stagnate before flowing into the center lower space 20C, ensuring balanced cooling of the entire battery module 30. This size relationship between the lower spaces 20C, 20S, combined with the dimensional setting of the partition 90, allows for more balanced cooling of the multiple battery modules 30.

[0132] (9C) The lower end of the side lower space 20S is defined by a slope surface 51X that is positioned downward toward the center in the vehicle width direction on at least a portion of the side inner bottom surface 51S. This ensures a volume of the side lower space 20S in which cooling air can remain, while suppressing interference with surrounding structures due to the side lower space 20S expanding toward the end in the vehicle width direction.

[0133] [II. Modifications] ==Battery Mounting Structure== The battery mounting structure described above is one example. For example, in the battery mounting structure, among multiple battery modules having the same vertical length, it is sufficient that the side modules are positioned so as to protrude upward relative to at least the center module, and the side modules and the center modules may be positioned at equal front-to-rear positions. With this battery mounting structure in which only the height positions of the battery modules are offset, a simple modification to a structure in which the battery modules are positioned at equal front-to-rear and height positions ensures flexibility in the layout of the surrounding structure around the battery modules.

[0134] The battery modules may have different lengths in the front-to-rear direction as long as they have the same length in the up-to-down direction. Note that the "length in the up-to-down direction" referred to here is treated as being equal even if there are differences to a certain extent, such as variations due to manufacturing lots of the battery modules or variations within the tolerance range. In other words, even if the battery modules have slightly different lengths in the up-to-down direction, they are considered to have the same length in the up-to-down direction. Note that the "length in the front-to-rear direction" of the battery modules is also treated as being equal even if there are differences to a certain extent, such as variations due to manufacturing lots of the battery modules or variations within the tolerance range.

[0135] The side modules may be disposed in an upper position above the center module so as not to overlap with it in the up-down direction when viewed from the vehicle width direction. In this case, greater flexibility in the layout of the peripheral structure relative to the battery modules can be ensured. The center modules do not have to be disposed at equal height positions, but may be disposed at different height positions. Furthermore, the side modules do not have to be disposed at equal height positions, but may be disposed at different height positions. In these cases, greater flexibility in the layout of the peripheral structure relative to the center module and the peripheral structure relative to the side modules can be ensured.

[0136] The surface defining the lower end of the side lower space is not limited to the above-described sloped surface, and other shapes may be adopted. The center lower space is not limited to a space whose vertical dimension is smaller than that of the side lower space. For example, if the vertical dimension of the side lower space is kept the same as that of the center lower space, the inner bottom surface of the side can be brought closer to the side module than in the above-described embodiment, thereby ensuring greater flexibility in the layout of the surrounding structure for the side module.

[0137] A vehicle to which the battery mounting structure is applied does not need to be provided with an exhaust pipe. In other words, the battery mounting structure may be applied to an electric vehicle that does not have an engine. At least one center module may be provided. The side modules may be disposed at both ends in the vehicle width direction, and are not limited to a configuration in which one module is provided on each side (two in total), but may be provided two on each side, or may have different numbers on each side (for example, one on the left and two on the right, three in total). In addition, the side lower space and center lower space do not need to be provided in the internal space of the battery pack case.

[0138] Battery Pack Air Intake Structure This is an example of the battery pack air intake structure described above. For example, the battery pack air intake structure may include at least an air intake formed on the top surface of the battery pack case and for taking air into the internal space of the battery pack case, an air intake cover that forms an air intake communicating with the vehicle interior space and covers the air intake from above while forming a gap between the air intake and the air intake between the top surface of the battery pack case and the air intake, and a rib that is provided with a gap communicating between the air intake and the air intake and that stands upright from at least one of the top surface of the battery pack case and the air intake cover into the gap.

[0139] The air intake cover only needs to have at least one air intake and at least one rib. The mesh member of the upper intake may be omitted, or even the upper intake may be omitted altogether. In these cases, a simple configuration can be used to prevent foreign matter from entering the interior space of the battery pack case.

[0140] Even when ribs are provided, the ribs are not limited to being erected so as to surround the periphery of the intake port, but may be provided separately on the right side (one side in the predetermined direction) and left side (the other side in the predetermined direction) of the intake port, with a pair of left and right ribs being spaced apart from each other. Alternatively, the ribs may be provided only on the right or left side of the intake port. Furthermore, the arrangement is not limited to one in which the entire area of ​​the rib overlaps with the intake port in the front-to-rear direction. In these cases, the area occupied by the rib in the gap is reduced compared to the rib 80 of the above embodiment, which is erected so as to surround the periphery of the intake port, thereby contributing to improving the efficiency of taking in cooling air from the intake port.

[0141] The shape of the air intake cover is not limited to a shape inclined so that the upper surface of the cover is positioned downward toward the air intake 71 or a shape with an upwardly sloping portion on the lower surface of the cover, and various shapes can be adopted depending on the surrounding structure, design requirements, etc. Furthermore, the extension range of the air intake cover is not limited to a range extending to the area covering the sheet metal edge from above, and various extension ranges can be set depending on the surrounding structure, design requirements, etc. Regarding the dimensions and arrangement of the ribs, various dimensions and arrangements can be adopted taking into consideration the effect of suppressing the intrusion of foreign matter, the efficiency of taking in cooling air, etc.

[0142] In addition, as a modified example of the battery pack air intake structure, a mesh-like structure stretched over the air intake may be provided instead of the rib 80 described above in the first embodiment. That is, the modified battery pack air intake structure may include an air intake formed on the top surface of the battery pack case to take air into the internal space of the battery pack case, an air intake cover that forms an air intake communicating with the vehicle interior space and covers the air intake from above while forming a gap between the air intake and the air intake between the top surface of the battery pack case, and a mesh-like structure stretched over the air intake. With this structure, foreign objects that attempt to enter the gap are captured by the mesh, thereby preventing foreign objects from entering the air intake. This prevents foreign objects from entering the internal space of the battery pack case.

[0143] ==Battery Module Cooling Structure== This is an example of the battery module cooling structure described above. For example, the partition portion does not need to have a constant (or approximately constant) shape in the vehicle width direction regardless of the position in the fore-aft direction. For example, as shown in FIG. 10 , the partition portion 90′ may be tapered such that the vehicle width direction dimension increases toward the front in the fore-aft direction (the side from the inlet 45B to the outlet 46C). This forward-tapering partition portion 90′ narrows the rear space of the lower space 20L more than the front space, achieving the same effect as the lower step portion 52 described in the above embodiment.

[0144] The battery module cooling structure may have at least three battery modules (one more than the number of partitions) and at least two partitions (one less than the number of battery modules). Note that if the partitions are integrated with components such as a battery pack case provided around the partitions, the number of partitions may be one or more.

[0145] Examples of simplified battery module cooling structures of the above-described embodiments include an inlet provided only at the left end or the right end of the lower space, and a partition provided only with a long partition or only with a short partition. The lower step and upper step may be omitted, and the baffle plate may be omitted. Regarding this battery module cooling structure, the vehicle width direction in the above-described embodiments may be interpreted as an arbitrary horizontal first direction, and the fore-aft direction in one embodiment may be interpreted as a horizontal second direction intersecting the first direction.

[0146] This invention can be applied to the manufacturing industry of battery-powered vehicles.

[0147] REFERENCE SIGNS LIST 10 Battery pack 15 Center module 16 Side module 20 Battery pack case 20A Internal space 20C Center lower space 20L Lower space 20S Side lower space 20U Upper space 23 Inner top surface 24 Upper step portion 26 Downstream top surface 27 Upstream top surface 30 Battery module 30C Battery cell 30L Lower end surface 30U Upper end surface 3E Sheet metal edge 45B Inlet 46C Outlet 49 Imaginary straight line path 51 Inner bottom surface 51C Center inner bottom surface 51S Side inner bottom surface 51X Slope surface 52 Lower step portion 53 Upstream bottom surface 54 Downstream bottom surface 90 Partition portion 90B Rear end 90F Front end 91 First partition portion (short partition portion) 92 Second partition section (long partition section) 93 Third partition section (long partition section) 94 Fourth partition section (long partition section) 95 Fifth partition section (short partition section) 99 Baffle plate

Claims

1. A battery module cooling structure comprising: an internal space in which three or more battery modules are arranged side by side in a horizontal first direction; a battery pack case having an air inlet into the internal space and an air outlet out of the internal space; and partitions extending in a horizontal second direction intersecting the first direction, disposed between adjacent battery modules, and erected upward from the inner bottom surface of the battery pack case, separating a lower space between the battery modules and the inner bottom surface; wherein the inlet and the outlet are located at different positions in the first direction and the second direction, the three or more battery modules are arranged on a path connecting the inlet and the outlet, and the distance from one end of the partition closer to the inlet in the second direction to one end of the internal space closer to the inlet in the second direction is longer for the partitions disposed closer to the inlet in relation to the outlet in the first direction.

2. The battery module cooling structure according to claim 1, characterized in that the inlet is provided at least at one end and the other end in the first direction in the lower space.

3. The battery module cooling structure described in claim 2, characterized in that the inlet is provided at each of one end and the other end of the lower space in the first direction, and the outlet is provided in the center between the inlet located at one end of the lower space in the first direction and the inlet located at the other end of the lower space in the first direction.

4. A battery module cooling structure as claimed in any one of claims 1 to 3, characterized in that the partitions have at least one of long partitions that extend longer than the dimension of the battery module in the second direction and short partitions that extend shorter than the dimension of the battery module in the second direction.

5. A battery module cooling structure as described in any one of claims 1 to 4, characterized in that a lower step portion is formed between a downstream bottom surface of the inner bottom surface that is located closer to the discharge outlet than the inlet in the second direction, and an upstream bottom surface of the inner bottom surface that is located closer to the inlet than the outlet in the second direction and is lower than the downstream bottom surface.

6. A battery module cooling structure as described in any one of claims 1 to 5, characterized in that an upper step portion is formed between a downstream top surface of the inner top surface that defines the upper end of the internal space and that is located closer to the discharge outlet than the inlet in the second direction, and an upstream top surface of the inner top surface that is located closer to the inlet than the outlet in the second direction and is lower than the downstream top surface.

7. A battery module cooling structure as claimed in any one of claims 1 to 6, characterized in that it comprises a baffle plate that is disposed above the battery module and below a downstream top surface of an inner top surface that defines the upper end of the internal space and is located closer to the outlet than the inlet in the second direction, and that obstructs the flow of air from below to above.

8. A battery module cooling structure as claimed in any one of claims 1 to 7, characterized in that the partition section is tapered so that the dimension in the first direction is longer on the side from the inlet to the outlet in the second direction.

9. The battery module cooling structure according to any one of claims 1 to 8, characterized in that the battery pack case houses side modules arranged at both ends of the battery modules in the first direction, and a center module arranged at the center of the battery modules in the first direction, the inner bottom surface having a side inner bottom surface located below the side modules and a center inner bottom surface located below the center module, and the lower space has a side lower space formed between the side modules and the side inner bottom surface and having the inlet, and a center lower space formed between the center module and the center inner bottom surface, communicating with the lower part of the side lower space and having a smaller vertical dimension than the side lower space.

10. The battery module cooling structure described in claim 9, wherein the side lower space is defined at its lower end by a sloped surface located downwards toward the center of the first direction on at least a portion of the side inner bottom surface.

Images