Vehicle with on-board battery placed under floor

Abstract

To provide a configuration capable of obtaining as large a vehicle interior space as possible and achieving good cooling of a battery module in a vehicle in which a battery module and a structure for cooling the battery module are arranged under a floor.SOLUTION: A vehicle 1 has a battery module 11 arranged under a floor, and the battery module, consisting of a plurality of battery cells 12 held in parallel horizontally by a frame member 13, is arranged above a bottom surface 10 of a vehicle body, and a flow path L for refrigerant air is defined by a lower surface of the battery module and an upper surface of the bottom surface of the vehicle body, and the refrigerant air flowing through the flow path is configured to reach a surface of a battery stack along the frame member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle in which an on-board battery is disposed under the floor, and more particularly to a vehicle in which a structure for cooling the on-board battery is provided under the floor. [Background technology]

[0002] As electric vehicles become more widespread, battery modules mounted on vehicles generate more heat than the auxiliary batteries of conventional vehicles, and various structures for cooling battery modules in vehicles have been proposed. For example, Patent Document 1 proposes a structure in which a flat battery module is arranged under the floor of a vehicle, in which a bottom frame on which the battery is placed is installed above the bottom of the vehicle body, and a coolant (air) for cooling the battery is circulated between the lower surface of the bottom frame and the upper surface of the bottom of the vehicle body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-137830 Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle in which a battery module is arranged under the floor, typically, as shown in FIG. 2(A), a plurality of battery cells 12 are each held upright and horizontally parallel by a frame member 13 above the bottom surface 10 of the vehicle body (battery module 11), and a flow path L is defined below the battery cells 12 by a partition wall 14, and cooling air is sent from a blower 16 via an intake duct 18 into the flow path L. The air coolant then passes through the flow path L, as shown by the arrows, and flows along the frame member 13 to the surfaces of the battery cells 12, cooling the battery cells 12. With this configuration, a space sp exists between the bottom surface 10 of the vehicle body and the partition wall 14 that defines the flow path L, and the vehicle interior space is accordingly narrowed. Furthermore, in the case of the configuration of Patent Document 1, as shown diagrammatically in FIG. 2(B), a refrigerant flow path L is defined on the upper surface of the vehicle body bottom portion 10, and there is no space corresponding to space sp. However, since the battery module is mounted on the bottom frame 15, a space is required for this, and since the refrigerant cannot flow to the periphery of the battery cells 12, depending on the thermal conductivity of the bottom frame 15, it may happen that sufficient cooling of the battery cells 12 is not achieved.

[0005] In view of the above circumstances, the main object of the present invention is to provide a configuration in a vehicle in which a battery module and a structure for cooling it are arranged under the floor, which can maximize the interior space of the vehicle and can effectively cool the battery module. [Means for solving the problem]

[0006] According to the present invention, the above-mentioned object is achieved by a vehicle in which a battery module is arranged under the floor, a battery module consisting of a plurality of battery cells held in parallel horizontally by a frame member is arranged above the bottom surface of the vehicle body, a flow path for refrigerant air is defined by the lower surface of the battery module and the upper surface of the bottom surface of the vehicle body, and the refrigerant air flowing through the flow path reaches the surface of the battery stack along the frame member.

[0007] In the above configuration, the vehicle may be any vehicle in which the battery module is disposed under the floor. The frame member that holds the battery cells may be, for example, a frame member made of a framework that positions the battery cells, and is configured so that the refrigerant air can flow by directly contacting the surfaces of the battery cells. The bottom surface of the vehicle body may be configured with a closed surface material to prevent water or mud from the ground from entering the vehicle. The upper surface of the bottom surface of the vehicle body faces the lower surface of the battery module and defines the flow path of the refrigerant, and structures such as partitions for controlling the flow of the refrigerant may be formed by integral molding of the vehicle body by die casting.

[0008] According to the above configuration, the upper surface of the bottom of the vehicle body forms part of the wall that defines the flow path of the coolant for cooling the battery module. This eliminates the space between the bottom of the vehicle body and the partition wall that defines the flow path, as was the case in the conventional structure shown in Figure 2(A). This makes it possible to make the vehicle interior space larger, and by lowering the height at which the battery modules are arranged, the center of gravity of the vehicle can be lowered. This is advantageous in that it improves the running stability of the vehicle, reduces the number of parts, and enables the heat of the battery module to be released to the outside of the vehicle interior.

[0009] In the above configuration, the refrigerant air may be introduced into the flow passage by any type of blower (forced air cooling). In this case, an intake duct is provided to connect the flow passage and the blower, and the underside of the intake duct may also be formed by the bottom surface of the vehicle body. This makes it possible to save on the material required for the intake duct. Effect of the Invention

[0010] Thus, according to the configuration of the present invention, as described above, it is possible to maximize the vehicle interior space and to effectively cool the battery module. The configuration of the present invention may be applied to any type of electric vehicle equipped with a traction battery.

[0011] Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the invention. [Brief description of the drawings]

[0012] [Figure 1] Fig. 1(A) is a schematic diagram of a vehicle to which the cooling structure for a battery module according to the present embodiment is applied, Fig. 1(B) is a schematic diagram of the cooling structure for a battery module under the floor of the vehicle according to the present embodiment, and Fig. 1(C) is a schematic diagram of a cross section of an intake duct in the present embodiment. [Diagram 2] 2(A) and (B) are schematic diagrams of examples of conventional cooling structures for battery modules under the floor of a vehicle. [Explanation of symbols]

[0013] 1...vehicle, 10...body bottom, 11...battery module, 12...battery cell, 13...frame member, 14...partition wall, 16...blower, 18...intake duct BEST MODE FOR CARRYING OUT THEINVENTION

[0014] The present invention will now be described in detail with reference to some preferred embodiments thereof with reference to the accompanying drawings, in which like reference numerals indicate like parts.

[0015] As shown in FIG. 1(A), the battery module cooling structure Bt according to the present embodiment is configured at the bottom under the floor of the vehicle 1. Referring to FIG. 1(B), in the present embodiment, the battery module 11 has a configuration in which a plurality of flat battery cells 12 are arranged in parallel in the horizontal direction in an upright state and sandwiched between a frame member 13, as in the past. The battery module 11 is disposed above the bottom surface 10 of the vehicle body. In the present embodiment, as shown in the figure, a flow path L through which a refrigerant (air) for cooling the battery module 11 flows is defined between the upper surface of the bottom surface 10 of the vehicle body and the lower surface of the battery module 11. The flow path L is connected to the air outlet of the blower 16 via an intake duct 18, and the air, which is the refrigerant, is sent from the blower 16 through the intake duct 18 to the flow path L and flows over the surfaces of the battery cells 12 along the frame member 13 as indicated by the arrows in the figure, thereby cooling each battery cell 12. In order to prevent the refrigerant from flowing out from the flow path L on the lower side of the battery module 11 without passing around the battery cells 12, the lateral periphery of the battery module 11 may be surrounded by a partition wall 14. In addition, in order to appropriately control the flow of the refrigerant on the upper surface of the bottom surface 10 of the vehicle body, a structure such as a partition may be formed integrally on the vehicle body by die casting. Furthermore, as shown in FIG. 1(C) , the lower side of the intake duct 18 may be defined by the upper surface of the bottom surface 10 of the vehicle body.

[0016] According to the configuration of the present embodiment, the refrigerant air flows to the surface of the battery cells 12, thereby achieving good cooling of the battery cells 12, and the flow path L is defined between the upper surface of the vehicle body bottom 10 and the lower surface of the battery module 11, and there is no space between the vehicle body bottom and the partition wall that defines the flow path as in the conventional structure (FIG. 2(A)). This makes it possible to make the vehicle interior space wider downward, and by lowering the height at which the battery module 11 is disposed, the center of gravity of the vehicle 1 can be lowered, thereby improving the running stability of the vehicle. Also, since there is no need to provide a member for defining the refrigerant flow path and the lower side of the intake duct separately from the vehicle body bottom, the number of parts is reduced, and this is expected to reduce costs.

[0017] The above description has been given in relation to the embodiment of the present invention, but it will be apparent to those skilled in the art that many modifications and changes can be easily made thereto, and that the present invention is not limited to the embodiment exemplified above, but can be applied to various devices without departing from the concept of the present invention.

Claims

[Claim 1] A vehicle having a battery module arranged under the floor, the battery module being constituted by a plurality of battery cells held in parallel horizontally by a frame member and arranged above the bottom surface of the vehicle body, a flow path for refrigerant air being defined by a lower surface of the battery module and an upper surface of the bottom surface of the vehicle body, and the refrigerant air flowing through the flow path reaches the surface of the battery stack along the frame member.

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