Battery mounting structure

Abstract

The battery mounting structure includes a center module (15) arranged in the center of the vehicle width direction among a plurality of battery modules (30) that are arranged side by side in the vehicle width direction in the internal space (20A) of a battery pack case (20) mounted on the vehicle and have equal lengths in the vertical direction of the vehicle, and side modules (16) that are arranged at both ends of the plurality of battery modules (30) in the vehicle width direction and protrude upward relative to the center module (15).

Description

[Technical field]

[0001] The present invention relates to a battery mounting structure for mounting a battery on a vehicle. [Background technology]

[0002] Vehicles such as electric vehicles and hybrid electric vehicles are equipped with a large-capacity battery (also called a battery pack) as a power supply source for driving the vehicle. A known example of a large-capacity battery is a plurality of battery modules housed in the internal space of a battery pack case. For example, a technology has been proposed in which all battery modules are arranged side by side in the same position at the same height (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-207237 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the structure in which all the battery modules arranged in a predetermined direction are arranged at the same height as described above, a surface (mounting surface) on which all the battery modules can be mounted at the same height is required, which may cause interference with the surrounding structures of the battery modules. For example, when a plurality of battery modules arranged in the vehicle width direction and at the same height are mounted on a vehicle, the battery modules on the outer side in the vehicle width direction may interfere with existing structures such as side members and exhaust pipes provided on the outer side in the vehicle width direction. This may lead to layout restrictions such as having to redesign the arrangement of structures provided around the battery modules or being unable to mount the desired number of battery modules. Therefore, there is room for improvement in terms of ensuring freedom in the layout of the peripheral structure for the battery module.

[0005] The battery mounting structure of the present invention was invented in consideration of such problems, and one of its objectives is to ensure the degree of freedom in the layout of the peripheral structure for the battery module. However, in addition to this objective, another objective of the present invention is to achieve the effects derived from the respective configurations shown in the "Description of Embodiments of the Invention" described later, which cannot be obtained by the conventional technology. [Means for solving the problem]

[0006] The disclosed battery mounting structure can be realized as the following disclosed aspects (application examples), which solve at least part of the above problems. Each of the aspects from aspect 2 onwards is an aspect that can be selected additionally as appropriate, and each of the aspects can be omitted. None of the aspects from aspect 2 onwards discloses an essential aspect or configuration for the present invention.

[0007] Aspect 1. The disclosed battery mounting structure includes a center module that is arranged in the center of a vehicle width direction among a plurality of battery modules that are arranged side by side in the internal space of a battery pack case mounted on a vehicle and have the same length in the vertical direction of the vehicle, and side modules that are arranged at both ends of the plurality of battery modules in the vehicle width direction and protrude upward relative to the center module. The side module is located at the outermost side of the plurality of battery modules on one side and the other side in the vehicle width direction. is.

[0008] Aspect 2. In the above aspect 1, it is preferable that the side module is disposed at a position where it partially overlaps with the center module in the up-down direction when viewed from the vehicle width direction. Aspect 3. In the above aspect 1 or 2, it is preferable that a plurality of the center modules are provided and are positioned at the same height, and that the side modules are positioned at the same height.

[0010] Aspects 4 .Aspect 1 above 3In any one of the above, it is preferable that the battery pack case is provided in a vehicle interior space and mounted below a front seat excluding a rearmost seat among a plurality of rows of seats aligned in a longitudinal direction of the vehicle. Aspects 5 .Aspect 1 above 4 In any one of the above, it is preferable that the plurality of battery modules have an equal length in a front-rear direction of the vehicle, and the side module is disposed so as to protrude forward relative to the center module.

[0011] Aspects 6 .Aspect 1 above 5 In any one of the above, it is preferable that the battery pack case has a side lower space formed between a side inner bottom surface located below the side module and the side module, into which air is introduced, and a center lower space formed between a center inner bottom surface located below the center module and the center module, communicating with a lower part of the side lower space, and having a smaller vertical dimension than the side lower space.

[0012] Aspects 7 The above aspects 6 In the vehicle, it is preferable that a lower end of the side lower space is defined by a slope surface that is positioned downward toward the center in the vehicle width direction in at least a portion of the side inner bottom surface. Aspects 8 .Aspect 1 above 7 In any one of the above, it is preferable that an exhaust pipe is disposed immediately below the end portion of the battery pack case in the vehicle width direction. Effect of the Invention

[0013] According to the disclosed battery mounting structure, it is possible to ensure a degree of freedom in the layout of the peripheral structure with respect to the battery module. [Brief description of the drawings]

[0014] [Figure 1] 1 is a longitudinal cross-sectional view seen from the front side of a vehicle, showing a battery pack to which a battery mounting structure according to an embodiment is applied and part of a structure provided around the battery pack. [Diagram 2] 2 is a cross-sectional view of the battery pack of FIG. 1 as viewed from above the vehicle. [Diagram 3] 2 is a schematic diagram showing paths through which cooling air circulates in the internal space of the battery pack of FIG. 1. [Figure 4] FIG. 2 is an exploded perspective view showing an overview of the battery pack in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] With reference to the drawings, an embodiment of a structure (including a battery mounting structure) related to a battery mounted on a vehicle will be described. The embodiments described below are merely examples, and are not intended to exclude the application of various modifications and techniques not explicitly stated in the following embodiments. Each configuration of the embodiments can be modified in various ways without departing from the spirit of the embodiments. In addition, they can be selected as necessary, or can be combined appropriately.

[0016] 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 forward direction. 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. In addition, 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 with respect 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.

[0017] The structure of a vehicle is often formed almost symmetrically (mirror symmetry with respect to a plane including the yaw axis and roll axis passing through the center of gravity of the vehicle), but it is not necessary to have a completely symmetrical shape. The type of vehicle to which the structure according to the embodiment is applied is not particularly limited, and the structure according to the embodiment can be applied to, for example, an electric vehicle (EV), a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), etc. A plug-in hybrid vehicle means a hybrid vehicle that can be externally charged to the battery or externally supplied with power from the battery. A plug-in hybrid vehicle is provided with a charging port (inlet) for inserting a charging cable through which power is supplied from an external charging facility and a socket (outlet) for external power supply.

[0018] I. One embodiment In the following embodiment, a battery mounting structure for mounting a battery (also called a battery pack) on a vehicle will be described.

[0019] [1. Configuration] Fig. 1 is a longitudinal cross-sectional view showing a battery pack 10 to which a battery mounting structure according to an embodiment is applied and a part of a 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 a path through which 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, a battery pack 10 is provided in a vehicle interior 1, and various structures and members are provided around the battery pack 10.

[0020] <Battery pack peripheral configuration> A seat 2 for a passenger to sit on is provided above the battery pack 10. The seat 2 exemplified here is a front seat (front seat) of at least two rows of seats lined up in the front-rear direction. For example, the driver's seat or the passenger seat is the seat 2. However, the seat 2 may be any front seat excluding the rearmost seat of multiple rows of seats lined up in the front-rear direction, and may be the frontmost seat or the second-to-front seat in a vehicle with three rows of seats lined up side by side.

[0021] 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 constitutes 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 between them in the vehicle width direction. A console 5 is provided between the driver's seat and the passenger seat which form the seat 2. The console 5 illustrated in Fig. 1 is provided separately from the panel member 3. This console 5 is provided with a cup holder 5H.

[0022] Below the battery pack 10, a body floor 6 is provided extending in a planar shape. Below the body floor 6, a pair of left and right side members 7 are provided extending in the fore-and-aft direction to support from below a pair of left and right side floors 6X, which are the portions of the body floor 6 at the vehicle width end sides (hereinafter also referred to as the "vehicle width outer sides"). This body floor 6 has a center floor 6Y, which is closer to the center of the vehicle width (inner in the vehicle width direction) than the side floors 6X, and 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.

[0023] In the vehicle exemplified in this embodiment, an exhaust pipe 8 is provided extending in the front-rear direction below the body floor 6 on the inside in the vehicle width direction 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 vehicle interior 1. In other words, since the lower end of the vehicle interior 1 is defined by the body floor 6, it can be said that the battery pack 10 is mounted in the lower part of the vehicle interior 1.

[0024] <Battery pack configuration> The battery pack 10 is an electric 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 configurations of the battery pack 10, including the battery modules 30, battery-related electrical components, and cooling equipment, will be described, followed by a description of the internal layout, and finally a description of the battery pack case 20 located below the seat 2.

[0025] ==Battery module== The battery module 30 is a secondary battery that can be charged as well as supply power. The battery module 30 generates heat when receiving and transmitting power, such as during power running when power is supplied to a drive motor (not shown) of the vehicle or during regeneration when the braking energy of the vehicle is converted into power and charged. The battery module 30 is a battery with a larger capacity than on-board batteries such as so-called 12V batteries and 24V batteries.

[0026] In the internal space 20A, above and below the battery module 30, a space 20L located below the battery module 30 (hereinafter referred to as the “lower space”) and a space 20U located above the battery module 30 (hereinafter referred to as the “upper space”) are formed. Each battery module 30 is an assembled battery in which a plurality of battery cells 30C (single cells, only one of which is marked in FIG. 3) are connected to one another as shown in Fig. 3. These battery cells 30C are connected in series and / or parallel in accordance with the design voltage, design capacity, etc. of the battery module 30.

[0027] 1 and 2 show an example in which multiple battery modules 30 of a common size are arranged in the same position in the vehicle width direction. Specifically, six battery modules 30 each having a common width, front-rear, and up-down dimensions (i.e., proportions) and a rectangular parallelepiped shape are arranged side by side in the same position 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 module 30 illustrated in this embodiment includes, 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.

[0028] Of these six battery modules 31-36, the four battery modules 32-35 arranged in the center in the vehicle width direction are referred to indiscriminately as a center module 15. Also, of the six battery modules 31-36, the battery modules 31, 36 arranged at both ends in the vehicle width direction are referred to indiscriminately as 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 side modules 16.

[0029] The internal space 20A in which the above-mentioned battery module 30 is housed also houses various battery-related electrical components and cooling devices. ==Battery-related electrical equipment== As shown in FIG. 1, examples of battery-related electrical equipment accommodated in the internal space 20A include a BMU 40 (Battery Management Unit), a transformer 41, a harness 42, and a junction box 43 (see FIGS. 2 to 4). The BMU 40 is an electronic control device that controls all the battery modules 30, and has, for example, a function of managing and monitoring the state of each battery module 30 and a function of A / D conversion (analog / digital conversion) of control signals.

[0030] The transformer 41 is a device that converts voltage. The 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 when converting the voltage. 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 outside, cutting off the power, and distributing power to the transformer 41.

[0031] ==Cooling equipment== 4, an example of the cooling device accommodated in the internal space 20A is an intake duct 45. Examples of cooling devices that are not accommodated in the internal space 20A and are provided outside the battery pack case 20 include a fan 44 and an exhaust duct 46. The fan 44 is an air-cooling 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 passage for the cooling air supplied by the fan 44.

[0032] The cooling by the cooling device is performed in the internal space 20A of the battery pack case 20 as will be 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 module 30. Then, after cooling the transformer 41, the cooling air in the upper space 20U is discharged through the exhaust duct 46 by the fan 44.

[0033] In the embodiment illustrated here, as shown in FIG. 4, a pair (two) of left and right intake ducts 45 are provided in the internal space 20A, and a fan 44 and an exhaust duct 46 are provided above the battery pack 10 in the center in the vehicle width direction. The intake duct 45 has an intake port 45A formed at an upstream end in the flow direction of the cooling air, and an introduction port 45B formed at a downstream end in the flow direction of the cooling air. The intake port 45A is an opening that takes in cooling air from the space of the vehicle interior 1 (vehicle interior space) into the internal space 20A. The introduction port 45B is an opening that introduces cooling air into the lower space 20L. That is, the cooling air that cools the battery module 30 is introduced from the introduction port 45B of the lower space 20L.

[0034] The intake ports 45A and the introduction ports 45B are each provided in two locations, the same as the number of intake ducts 45. Specifically, the intake ports 45A are provided at the left and right ends of the upper surface of the battery pack case 20. Also, the introduction ports 45B are provided at the left and right ends (one end and the other end in the first direction) of the lower space 20L. However, only one intake duct 45 may be provided, and the inlet 45B may be provided at either the left end or the right end of the lower space 20L.

[0035] 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 flow direction of the 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, to the inside of an instrument panel (not shown).

[0036] 3, the cooling air in the upper space 20U flows from an exhaust port 46C communicating with the upper space 20U to the fan 44. That is, the cooling air that has cooled the battery modules 30 is exhausted from the exhaust port 46C of the upper space 20U. 2, the illustrated discharge outlet 46C is disposed at a different position in the vehicle width direction and in the front-rear direction from the inlet 45B. Specifically, the discharge outlet 46C is disposed at the center and rear side of the inlet 45B in the vehicle width direction. In other words, focusing on the position in the vehicle width direction, the discharge outlet 46C is provided in the middle between the inlet 45B at the left end and the inlet 45B at the right end in the vehicle width direction.

[0037] Each of the battery modules 30 is disposed on a straight line 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 disposed in such a relative arrangement that the virtual straight line path 49 crosses all of the battery modules 30.

[0038] ==Internal arrangement== Next, the arrangement of the battery modules 30, the battery-related electrical components, and the cooling devices of the battery pack 10 will be described. As shown in FIG. 4, the BMU 40, the transformer 41, and the junction box 43 are arranged together at the center or front in the vehicle width direction in the internal space 20A.

[0039] 1 and 4 show an example in which the BMU 40 and the 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 shown as an example. In addition, the junction box 43 is arranged in front of the center module 15 as shown in FIG. It should be noted that the BMU 40, transformer 41, and junction box 43 are not disposed 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 designing its layout than the center module 15, while the center module 15 has more restrictions on changing its layout than the side module 16.

[0040] The harness 42 is connected to the BMU 40, the transformer 41, the junction box 43, and the like, and is therefore routed at least above and in front of the center module 15. 4, the intake duct 45 extends across the vehicle width direction outer side and front side of each of the left and right side modules 16. In the illustrated intake duct 45, an intake port 45A is disposed on the vehicle width direction outer side of each side module 16 in a plan view, and an introduction port 45B is disposed on the front side of each side module 16 in a plan view.

[0041] In addition, the fan 44 and the exhaust duct 46 are disposed above the battery pack case 20 rather than in the internal space 20A. Here, the fan 44 is disposed above the transformer 41, and the exhaust duct 46 extends forward from the fan 44. 1, the seat 2 is not installed in the internal space 20A but above the battery pack 10, and above the outer halves of the second battery module 32 and the fifth battery module 35 of the center module 15 in the vehicle width direction, and above the entire side module 16. The battery pack case 20 thus mounted below the seat 2 will be described next.

[0042] ==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 Fig. 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.

[0043] The tray 21 has a bottom wall portion 50 and a side wall portion 60 standing upright from the peripheral edge of the bottom wall portion 50 . The bottom wall portion 50 is provided with an inner bottom surface 51 that defines the lower end of the internal space 20A. The "inner bottom surface 51" here means 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 portion 50. The inner bottom surface 51 extends below the battery module 30 via the lower space 20L. That is, the battery module 30 and the inner bottom surface 51 are spaced apart from each other.

[0044] In this embodiment, the inner bottom surface 51 is divided 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. Similarly, the lower space 20L is divided 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 with each other, allowing cooling air to circulate throughout the entire lower space 20L.

[0045] The exhaust pipe 8 is disposed directly below the end of the tray 21 (battery pack case 20) in the vehicle width direction. Lid 22 is a member that forms the upper surface of battery pack case 20. As shown in Fig. 4, lid 22 is provided with an intake port 45A that takes in cooling air into internal space 20A. Here, upward-facing intake port 45A is provided on the upper surface of battery pack case 20, and an intake port cover 70 is provided to cover intake port 45A.

[0046] The battery mounting structure relating to the layout of the battery module 30 will be described in detail below. In a structure in which all battery modules arranged in a predetermined direction are disposed at the same height (hereinafter referred to as the "comparative structure"), a surface on which all battery modules can be mounted at the same height (i.e., a mounting surface in an area in which all battery modules extend at a certain height) is required, which may cause interference with the surrounding structures of the battery modules. For example, as in this embodiment, if there are existing structures such as side members 7 and exhaust pipes 8 on the outer side of the battery pack 10 in the vehicle width direction, in the comparative structure, there is a possibility that the battery modules on the outer side in the vehicle width direction may interfere with these existing structures. Therefore, measures such as redesigning the arrangement of the surrounding structures of the battery modules or reducing the number of battery modules are required.

[0047] 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 according to the placement location of the battery module 30, thereby ensuring freedom in the layout of the surrounding structure for the battery module 30.

[0048] In the battery mounting structure of this embodiment, as shown in Figures 1 and 4, the side module 16 is disposed so as to protrude upward with respect to the center module 15. In other words, the height position of the side module 16 is disposed so as to be offset (displaced) upward with respect to the center module 15. In other words, the center module 15 is disposed so as to protrude downward with respect to the side module 16. In other words, the height position of the center module 15 is disposed so as to be offset downward with respect to the side module 16. Such an offset arrangement in the vertical direction can also be said as an arrangement in which the position of the side module 16 is raised among the multiple (e.g., six) battery modules 30 (31-36).

[0049] The side module 16 illustrated here is disposed at a position where it partially overlaps the center module 15 in the vertical direction when viewed from the vehicle width direction. This arrangement can be said to be an arrangement where all of the battery modules 30 overlap at least a portion of the vertical area, and can also be said to be an arrangement where the side module 16 is not raised too high above the entire center module 15. In addition, the center modules 15 are arranged at equal height positions, and the side modules 16 are also arranged at equal height positions.

[0050] Regarding the battery module 30 in which the relative height positions of the center module 15 and the side modules 16 are set as described above, an explanation will be given below with reference to FIG. 1 regarding the height positions of the peripheral structure of the battery pack 10 with reference to the side members 7. A lower portion (part) of the center module 15 is disposed at a height position where it overlaps with the side member 7 when viewed from the vehicle width direction. On the other hand, the side module 16 does not overlap with the side member 7 when viewed from the vehicle width direction, and is disposed at a height position higher than the side member 7. Such an arrangement of the battery module 30 relative to the side member 7 can be said to be an arrangement in which the center module 15 fits between the side members 7, and can also be said to be a recessed arrangement in which the side module 16 is recessed upward to avoid interference with the side member 7 (peripheral structure).

[0051] Regarding the height position of the bottom end surface 30L of the battery module 30 based on the top end 7U of the side member 7, the bottom end surface 30L of the center module 15 (only one portion is marked with a reference symbol in FIG. 1) is disposed below the top end 7U of the side member 7. Meanwhile, the bottom end surface 30L of the side module 16 is disposed above the top end 7U of the side member 7.

[0052] The side lower space 20S formed below the side module 16 that is 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 center lower space 20C has a smaller vertical dimension than the side lower space 20S. This makes it easier for cooling air to accumulate in the side lower space 20S than in the center lower space 20C, so that the portion of the lower part of the battery module 30 that is closer to the inlet 45B than the outlet 46C can sufficiently exchange heat with the cooling air. The lower part of the side lower space 20S is in communication with the center lower space 20C.

[0053] The side lower space 20S is defined at its lower end by a slope surface 51X that is located downward (inclined downward) in at least a part 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.

[0054] Furthermore, the side module 16 provided in the battery mounting structure exemplified in this embodiment is disposed so as to protrude forward relative to the center module 15, as shown in Fig. 2. In other words, the position of the side module 16 in the front-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 module 16. In other words, the position of the center module 15 in the front-rear direction is offset rearward relative to the side module 16. Such an offset arrangement in the front-rear direction can also be said as an arrangement in which the side module 16 out of the multiple (e.g., six) battery modules 30 (31-36) is positioned forward.

[0055] A rear wall portion 61 is provided on the side wall portion 60 of the battery pack case 20 so as to extend in an upright direction behind the battery module 30 in accordance with the outer shape of the battery module 30 in which the relative front-to-rear positions of the center module 15 and the side module 16 are set as described above. Specifically, of the rear wall 61, a portion (hereinafter referred to as a "side portion") 61S provided on the rear side of the side module 16 is provided forward from a portion (hereinafter referred to as a "center portion") 61C provided on the rear side of the center module 15. That is, the center portion 61C of the rear wall 61 at the center in the vehicle width direction is provided in a shape that protrudes rearward.

[0056] 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 formed at positions shifted forward. The front wall 62 erected on the side wall 60 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 front wall 62, which does not have any concave or convex shape in the front-rear direction, and the center module 15. That is, the side module 16 is disposed offset forward without changing the layout of the junction box 43 disposed in front of the center module 15.

[0057] [2. Actions and Effects] Since this embodiment is configured as described above, the following actions and effects can be obtained. (1) In the battery mounting structure of this embodiment, the side module 16 is disposed to protrude upward relative to the center module 15. Therefore, when the above-described battery mounting structure is applied to an existing structure in which the side members 7, the exhaust pipe 8, etc. are provided, it becomes easier to avoid interference between the existing structure and the side module 16 and the center module 15. For example, the center module 15 fits between the side members 7, and the battery module 30 can be mounted below the seat 2. In this way, according to the above-described battery mounting structure, the battery module 30 can be mounted without changing the existing structure. Therefore, the degree of freedom in the layout of the surrounding structure for the battery module 30 can be ensured.

[0058] (2) In this embodiment, the side module 16 is disposed in a position where it partially overlaps with the center module 15 in the vertical direction when viewed from the vehicle width direction. Therefore, the vertical dimension of the battery pack case 20 can be prevented from increasing, compared to a configuration in which the side module 16 is disposed higher than the entire center module 15. In this way, the battery pack case 20 can be prevented from becoming larger, and this also ensures freedom in the layout of the surrounding structure for the battery module 30.

[0059] (3) The center modules 15 are disposed at equal height positions, and the side modules 16 are also disposed at equal height positions. This allows a space with a wide bottom surface area where multiple top surfaces of the center modules 15 are lined up to 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 equipment such as the BMU 40 and the transformer 41. In addition, the center modules 15 arranged at the same height as one another contribute 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 the same height as one another, the layout of the battery modules 30 can be prevented from becoming complicated.

[0060] (4) Of the six battery modules 30, the two side modules 16 are positioned on the outermost sides in the vehicle width direction. Therefore, compared to a battery mounting structure in which more than two side modules 16 are provided, it is possible to both prevent the center of gravity of the vehicle from becoming high and ensure freedom in the layout of the surrounding structure for the battery modules 30.

[0061] (5) The battery pack case 20 is mounted below the seat 2, and the side module 16 is disposed in the internal space 20A of the battery pack case 20 with its position in the front-rear direction offset forward from 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 getting in and out of the vehicle for passengers getting in and out of the seat immediately behind the seat 2. For example, the ease of putting the legs in for passengers getting in the second row rear seat relative to the driver's seat or passenger seat 2 can be improved. In addition, passengers sitting in seats adjacent to the rear of the seat 2 (i.e., while riding) can easily stretch their legs, improving the livability of the vehicle interior 1.

[0062] (6) Because the center lower space 20C is smaller than the side lower space 20S, the cooling air is more likely to stagnate in the side lower space 20S than in the center lower space 20C. As a result, the cooling air in the side lower space 20S stagnates before flowing into the center lower space 20C, allowing the entire battery module 30 to be cooled in a balanced manner. (7) The lower end of the side-lower space 20S is defined by a slope surface 51X that is located downward toward the center in the vehicle width direction in at least a part of the side inner bottom surface 51S. Therefore, the volume of the side-lower space 20S in which the cooling air can be retained can be secured, while interference with surrounding structures due to the side-lower space 20S expanding toward the end in the vehicle width direction can be suppressed.

[0063] (8) In addition, since the side module 16 is disposed with its height position offset upward with respect to the center module 15, the side module 16 can be disposed away from the exhaust pipe 8, and heating of the side module 16 due to radiant heat from the exhaust pipe 8 can be suppressed. In this way, the side module 16 is prevented from receiving heat from the exhaust pipe 8, which contributes to improving the cooling performance of the side module 16.

[0064] [II. Modifications] The above-described embodiment is an example. For example, in the battery mounting structure, among a plurality of battery modules having the same length in the up-down direction, it is sufficient that the side modules are arranged to protrude upward relative to at least the center module, and the side modules and the center modules may be arranged at equal positions in the front-rear direction. According to the battery mounting structure in which only the height positions of the battery modules are offset in this way, it is possible to ensure the layout freedom of the peripheral structure for the battery modules by simply making a simple change in the arrangement of the battery modules arranged at equal positions in the front-rear direction and height positions.

[0065] The multiple 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 in the degree of variation due to manufacturing lots of the battery modules or variations within the tolerance range. In other words, even if the lengths of the multiple battery modules in the up-to-down direction differ slightly, 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 multiple battery modules is also treated as being equal even if there are differences in the degree of variation due to manufacturing lots of the battery modules or variations within the tolerance range.

[0066] The side modules may be disposed in an upper position above the center module so as not to overlap with the center module in the vertical direction when viewed in the vehicle width direction, which can ensure greater freedom in layout of the peripheral structure of the battery module. The center modules are not limited to being arranged at equal height positions, but may be arranged at different height positions. The side modules are not limited to being arranged at equal height positions, but may be arranged at different height positions. In these cases, greater freedom in the layout of the peripheral structure for the center module and the peripheral structure for the side modules can be ensured.

[0067] The surface that defines the lower end of the side-lower space is not limited to the above-mentioned slope surface, and other forms 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 bottom surface of the inner side can be brought closer to the side module than in the above-mentioned embodiment, and further freedom in the layout of the surrounding structure for the side module can be ensured.

[0068] The vehicle to which the battery mounting structure is applied does not need to be provided with an exhaust pipe, that is, the battery mounting structure may be applied to an electric vehicle that is not equipped with an engine. It should be noted that at least one center module is required, while the side modules are required to be located at both ends in the vehicle width direction, and are not limited to a configuration in which one is provided on each side (two in total), but may be provided two on each side, or the numbers provided on the left and right sides may be different (for example, one on the left and two on the right, for a total of three). Additionally, the side lower space and the center lower space do not have to be provided in the internal space of the battery pack case. [Industrial Applicability]

[0069] The present invention is applicable to the manufacturing industry of vehicles equipped with batteries. [Explanation of symbols]

[0070] 1 Cabin 2 seats (front seats) 8. Exhaust pipe 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 30 Battery Module 51 Inner bottom surface 51C Center inner bottom 51S Side inner bottom 51X Slope surface

Claims

1. a center module disposed at a center portion in the vehicle width direction among a plurality of battery modules arranged side by side in an internal space of a battery pack case mounted on a vehicle and having equal lengths in a vertical direction of the vehicle; and side modules are disposed at both ends of the plurality of battery modules in the vehicle width direction and protrude upward relative to the center module, The side modules are positioned outermost on one and the other sides of the plurality of battery modules in the vehicle width direction. A battery mounting structure comprising:

2. The side module is disposed at a position where a part of the side module overlaps with the center module in the up-down direction when viewed from the vehicle width direction. The battery mounting structure according to claim 1 .

3. The center module is provided in plurality, and is arranged at the same height position. The side modules are arranged so that the height positions are equal to each other. The battery mounting structure according to claim 1 or 2.

4. The battery pack case is provided in a vehicle interior space and is mounted under a front seat excluding a rearmost seat among a plurality of rows of seats arranged in a longitudinal direction of the vehicle. The battery mounting structure according to claim 1 or 2.

5. The plurality of battery modules have equal lengths in a front-rear direction of the vehicle, The side module is disposed so as to protrude forward with respect to the center module. The battery mounting structure according to claim 1 or 2.

6. The battery pack case includes: a side lower space formed between the side module and an inner bottom surface of the side module located below the side module and into which air is introduced; a center lower space formed between the center module and a center inner bottom surface located below the center module, communicating with a lower portion of the side lower space and having a vertical dimension smaller than that of the side lower space; The battery mounting structure according to claim 1 or 2.

7. The side lower space is defined at its lower end by a slope surface that is located downward toward the center in the vehicle width direction in at least a portion of the side inner bottom surface. The battery mounting structure according to claim 6 .

8. an exhaust pipe is disposed immediately below the end of the battery pack case in the vehicle width direction; The battery mounting structure according to claim 1 or 2.

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