JP7135492B2 - Vehicle battery mounting structure - Google Patents

Description

The present invention relates to a mounting structure for a battery mounted on a vehicle to supply electric power for driving the vehicle.

2. Description of the Related Art Conventionally, vehicles that run by driving an electric motor for running with electric power stored in a battery have been widely used. Such a vehicle battery is composed of a plurality of battery modules so as to provide a large output and large capacity battery for power supply for driving the vehicle. The battery for driving the vehicle is large and heavy, and there is a risk of fire due to damage due to impact. are placed in

Objects such as rocks thrown up by the tires and water collide with the lower side of the floor panel of the passenger compartment. be. For this reason, a plurality of battery modules are housed in a case for protection from foreign objects and the like, and the case is mounted under the floor panel to be mounted on the vehicle.

The temperature of the battery rises due to heat generation and Joule heat associated with chemical reactions during charging and discharging, and the progress of deterioration is accelerated at high temperatures, so cooling is required. Therefore, as in Patent Document 1, for example, cooling air is circulated in a case housing the battery module to release the heat. In this case, it is necessary to secure a cooling air passage in the case, so it is difficult to increase the capacity by arranging a plurality of battery modules in the case at high density. Therefore, for example, as in Patent Document 2, a passage for cooling air is secured in the case and a plurality of battery modules are vertically stacked in two tiers to increase the number of mounted battery modules and increase the capacity.

Japanese Patent No. 5477256 Japanese Patent No. 4940966

When the cooling air is circulated in the case, the electric power supplied from the battery drives the blower fan, so the amount of electricity stored decreases. In addition, since the case is provided with an inlet and an outlet for the cooling air, there is a risk that water may enter the case through the inlet and the like.

For this reason, it is being considered to dissipate the heat of the battery modules to the outside through the case by watertightly housing a plurality of battery modules in the case and closely contacting the housed battery modules to the bottom of the case. However, when a plurality of battery modules are vertically stacked in two layers and accommodated in a case for increasing the capacity, it is difficult to dissipate heat from the upper battery module.

SUMMARY OF THE INVENTION An object of the present invention is to provide a battery mounting structure capable of dissipating the heat of the upper battery module of a plurality of battery modules stacked in two to the outside through a case.

The invention of claim 1 is a vehicle battery mounting structure comprising a case for accommodating a plurality of battery modules for driving the vehicle under a floor panel of a vehicle compartment, wherein the plurality of battery modules are divided into a lower module and an upper module. The case has a metal lower case member, a metal middle case member, and an upper case member for covering a predetermined area of the upper surface of the middle case member from above, and the lower module is fixed to the bottom of the lower case member, the middle case member is fixed to the lower case member so as to cover the lower module from above, and the lower module is housed in a watertight manner, and the upper module is the The upper case member is fixed in close contact with the upper surface of the middle case member within a predetermined area, and the upper case member is formed in a container shape having an opening at the bottom, and covers the predetermined area to cover the peripheral edge of the opening. is fixed in close contact with the upper surface of the middle case member to house the upper module in a watertight manner, and the case is fixed to the vehicle by attaching the lower case member to the lower side of the floor panel , The rear portion of the floor panel is formed higher than the front portion, and the upper case member is disposed below the rear portion .

According to the above configuration, a plurality of battery modules for a vehicle that runs using power stored in the battery modules are vertically stacked in two stages to increase the number of battery modules that can be mounted on the vehicle. The lower module of the two-tiered stack is watertightly accommodated by the lower case member and the middle case member, the upper module of the two-tiered stack is watertightly accommodated by the middle case member and the upper case member, and pebbles during running. Prevent collisions and flooding. In order to release the heat of the upper module to the outside of the case, the upper module is brought into close contact with the upper surface of the metal middle case member to transfer heat to the middle case member. Since the middle case member radiates heat to the outside by heat radiation, running wind, etc., it is possible to cool the upper module housed in the case in a watertight manner. Moreover, since the upper case member protruding upwards from the middle case member is arranged below the rear portion of the floor panel which is formed higher than the front portion of the floor panel of the passenger compartment, it is possible to match the shape of the floor panel. Therefore, the space under the floor panel can be used to increase the number of battery modules to be mounted.

According to a second aspect of the invention, there is provided a battery mounting structure for a vehicle, which includes a case for accommodating a plurality of battery modules for driving the vehicle under a floor panel of a vehicle compartment, wherein the plurality of battery modules are divided into a lower module and an upper module. The case has a metal lower case member, a metal middle case member, and an upper case member for covering a predetermined area of the upper surface of the middle case member from above, and the lower module is fixed to the bottom of the lower case member, the middle case member is fixed to the lower case member so as to cover the lower module from above, and the lower module is housed in a watertight manner, and the upper module is the The upper case member is fixed in close contact with the upper surface of the middle case member within a predetermined area, and the upper case member is formed in a container shape having an opening at the bottom, and covers the predetermined area to cover the peripheral edge of the opening. is fixed in close contact with the upper surface of the middle case member to house the upper module in a watertight manner, and the case is fixed to the vehicle by attaching the lower case member to the lower side of the floor panel , A plurality of metal support members for supporting the middle case member are arranged between the lower case member and the middle case member below the upper module.
According to the above configuration, a plurality of battery modules for a vehicle that runs using power stored in the battery modules are vertically stacked in two stages to increase the number of battery modules that can be mounted on the vehicle. The lower module of the two-tiered stack is watertightly accommodated by the lower case member and the middle case member, the upper module of the two-tiered stack is watertightly accommodated by the middle case member and the upper case member, and pebbles during running. Prevent collisions and flooding. In order to release the heat of the upper module to the outside of the case, the upper module is brought into close contact with the upper surface of the metal middle case member to transfer heat to the middle case member. Since the middle case member radiates heat to the outside by heat radiation, running wind, etc., it is possible to cool the upper module housed in the case in a watertight manner. Moreover, by supporting the middle case member with a plurality of support members, the downward deflection of the middle case member due to the weight of the upper module is prevented, thereby preventing contact between the middle case member and the lower module, thereby preventing problems such as short circuits. can do.

According to the vehicle battery mounting structure of the present invention, the heat of the upper battery module of the two-tiered battery modules can be released to the outside through the case.

1 is a plan view of a main portion of a vehicle according to an embodiment of the present invention as viewed from below; FIG. 1 is a perspective view of a battery pack according to an embodiment of the present invention; FIG. FIG. 3 is an exploded perspective view of the main parts of the battery pack of FIG. 2; FIG. 2 is a cross-sectional view taken along line IV-IV of FIG. 1; FIG. 2 is a cross-sectional view taken along line VV of FIG. 1; FIG. 2 is an exploded perspective view of the essential parts of the battery module;

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on an Example.

First, the configuration of the vehicle 1 will be described based on FIG. An example of an electric vehicle will be described as the vehicle 1, but it may be a hybrid type vehicle that runs on an engine and an electric motor, or a range extender type vehicle that is equipped with a power generator for charging a battery module while running. good too. Arrow F in the drawing indicates the front of the vehicle, and arrow L indicates the left of the vehicle.

A vehicle 1 includes an electric motor 2 that drives drive wheels to rotate, and a battery pack 3 that has a plurality of battery modules that supply electric power to the electric motor 2 . The battery pack 3 is arranged below a floor panel 4 of the vehicle compartment, and is attached to a frame member having a closed cross section such as a floor frame 5 extending in the longitudinal direction of the vehicle 1 and a cross member 6 extending in the vehicle width direction. It is fixed by and mounted on the vehicle 1 .

Next, the battery pack 3 will be described with reference to FIGS. 2 and 3. FIG. Arrow F in the drawing indicates the front of the vehicle, arrow L indicates the left of the vehicle, and arrow U indicates the upper direction.
The battery pack 3 has a case 8 with a rear portion higher than a front portion, and accommodates, for example, 16 battery modules M1 to M16 as a plurality of battery modules. These battery modules M1 to M16 are connected in series by a plurality of bus bars 9, and are configured to supply power for driving the vehicle to the electric motor 2 and the like from a power supply cable (not shown). The number of battery modules accommodated in the case 8 is appropriately set according to the specifications of the vehicle 1 in which the battery pack 3 is mounted.

Next, the battery module will be explained. Since the battery modules M1 to M16 have the same configuration, the battery module M1 will be described, and the description of the other battery modules M2 to M16 will be omitted.
As shown in FIG. 6, the battery module M1 consists of a pair of bundling units for integrating, for example, 12 prismatic lithium-ion secondary batteries (storage batteries 21) aligned in a row in the horizontal direction. A member 22 and a pair of end plates 23 are connected and fixed. An insulating separator 24 is sandwiched between adjacent storage batteries 21 . An electric heater 25 is attached to one of the pair of binding members 22 to warm the battery module M1 at low temperatures. A flat plate-shaped cover member 26 is attached to the upper portion of the battery module M1.

In the battery module M1, a storage battery pair is formed by connecting two storage batteries 21 in parallel by a plurality of bus bars 27, and six storage battery pairs are connected in series. A terminal 29 is provided. Although not shown, the storage battery 21 has a wound or laminated electrode body formed by sandwiching a porous separator sheet between a positive electrode plate and a negative electrode plate. It is hermetically housed together with the aqueous electrolyte. The storage battery case has a positive terminal 21a connected to the positive plate of the electrode body and a negative terminal 21b connected to the negative plate of the electrode body, and a bus bar 27 is connected to the upper part of the storage battery case.

Next, a battery mounting structure will be described based on FIGS. 1 to 5. FIG.
The case 8 of the battery pack 3 is constructed by a lower case member 11, a middle case member 12, and an upper case member 13 so as to watertightly accommodate the battery module M1 and the like. In order to prevent the case 8 from being deformed by the pressure difference between the air inside the case 8 and the outside air, the middle case member 12 and the upper case member 13 are covered with a film member having a function of passing air and blocking liquid water. and a pressure adjustment port (not shown).

The lower case member 11 includes a frame portion 11a in which a plurality of metal (for example, steel) frame members extending in the front-rear direction and the vehicle width direction of the vehicle 1 and having a closed cross section are joined in a lattice shape having an outer frame; It has a panel portion 11b made of metal (for example, made of an aluminum alloy) that connects between a plurality of frame members of the frame portion 11a. The lower case member 11 has rigidity for supporting the heavy battery module M1 and the like, and also protects the battery module M1 and the like from impact due to a vehicle collision or the like. The battery pack 3 is mounted on the vehicle 1 with the lower case member 11 attached to the lower side of the floor panel 4.

The middle case member 12 is a cover member made of metal (for example, aluminum alloy) having good thermal conductivity. The middle case member 12 includes a substantially flat middle case upper surface portion 12a, a middle case peripheral wall portion 12b extending downward from the outer peripheral portion of the middle case upper surface portion 12a, and a flange-shaped lower end portion of the middle case peripheral wall portion 12b. It has a middle case lower surface portion 12c.

The middle case lower surface portion 12 c has a plurality of fixing portions 12 d for fixing to the frame portion 11 a of the lower case member 11 . A plurality of reinforcing members 12e are arranged on the inner peripheral side of the middle case peripheral wall portion 12b and the lower surface side of the middle case top surface portion 12a to suppress deformation of the middle case top surface portion 12a due to its own weight. Concavities and convexities for suppressing deformation due to its own weight may be formed on the middle case upper surface portion 12a.

The upper case member 13 is a cover member that is made of a conductive material (eg, aluminum alloy) or made of a synthetic resin material and has an inner wall surface that is made conductive by, for example, a zinc thermal spray coating. The upper case member 13 is grounded to the vehicle 1 via the middle case member 12 and the lower case member 11 or by a ground cable (not shown). The upper case member 13 is formed in the shape of a container having an opening at the bottom, and includes an upper case upper surface portion 13a (an upper surface portion of the upper case member 13) and an upper case peripheral wall portion extending downward from the outer peripheral portion of the upper case upper surface portion 13a. 13b, and an upper case lower surface portion 13c (peripheral portion of the opening at the bottom) provided in a flange shape at the lower end portion of the upper case peripheral wall portion 13b.

The plurality of battery modules M1 to M16 are divided into a lower module 15 and an upper module 16, and the upper module 16 is arranged above the lower module 15 (stacked in two layers) and housed in the case 8. FIG.

The lower module 15 is composed of, for example, battery modules M1 to M13, and the bottom surface of the storage battery 21 of the battery modules M1 to M13 is attached to the panel portion 11b at the bottom of the lower case member 11 with a heat transfer sheet 15a (for example, a heat conductive silicon sheet). They are fixed by bolts (not shown) or the like in a state where they are brought into close contact with each other. The middle case member 12 is covered from above on the lower case member 11 to which the lower module 15 is fixed, and a plurality of fixing portions 12d of the middle case member 12 are fixed to the frame portion 11a of the lower case member 11 by bolts (not shown) or the like. It is The lower module 15 is watertightly accommodated by the lower case member 11 and the middle case member 12 so as to adhere to the lower case member 11 and not contact the middle case member 12 .

The panel portion 11b is formed with unevenness corresponding to each of the battery modules M1 to M13, and the upwardly protruding portion contacts the bottom portion of the storage battery 21 via the heat transfer sheet 15a. The panel portion 11b radiates the heat transferred from the lower module 15 to the outside by thermal radiation, running wind, or the like. A seal member 11c is provided between the middle case lower surface portion 12c and the frame portion 11a or panel portion 11b of the lower case member 11 to prevent water from entering. The seal member 11c preferably has electrical conductivity for good conduction between the lower case member 11 and the middle case member 12, and more preferably has good thermal conductivity. The middle case lower surface portion 12c is formed along the shape of the lower case member 11 that comes into contact via the seal member 11c in order to ensure good watertightness. Also, a sealing material may be filled and applied so as to fill the gap between the middle case lower surface portion 12 c and the lower case member 11 .

The upper module 16 is composed of, for example, battery modules M14 to M16, and the bottom surfaces of the storage batteries 21 of the battery modules M14 to M16 are placed within a predetermined area of the rear portion of the middle case upper surface 12a with a heat transfer sheet 16a (for example, a heat conductive sheet). They are fixed by bolts or the like in a state where they are brought into close contact with each other via a silicon sheet). Concavities and convexities corresponding to the respective battery modules M14 to M16 are formed on the middle case upper surface 12a, and the upwardly protruding portion contacts the bottom surface of the storage battery 21 via the heat transfer sheet 16a. Below the upper module 16, between the lower case member 11 and the middle case member 12, a plurality of metal (for example, aluminum alloy) support members 17 to 19 for supporting the middle case member 12 are arranged. ing.

The support member 17 includes a main body portion 17a erected substantially vertically, a top portion 17b extending horizontally from the upper end portion of the main body portion 17a for fixing to the middle case upper surface portion 12a, and a lower case member 11 extending in the vehicle width direction. It has a bottom portion 17c extending horizontally from the lower end of body portion 17a for securing to a vertically extending frame member. The support members 18 and 19 are composed of main body portions 18a and 19a which are erected substantially vertically, and top portions 18b which extend horizontally from the upper end portions of the main body portions 18a and 19a for fixing to the upper surface portion 12a of the middle case. 19b and bottom portions 18c, 19c extending horizontally from the lower ends of the body portions 18a, 19a for fixing to the panel portion 11b of the lower case member 11. As shown in FIG.

The support members 17 to 19 are fixed to the lower case member 11 and the middle case member 12 by bolts (not shown) or the like, but are joined to either the lower case member 11 or the middle case member 12 by welding or the like. good too. These supporting members 17 to 19 prevent the middle case upper surface 12 a from bending downward due to the weight of the upper module 16 and contacting the lower module 15 . Further, heat is transferred between the lower case member 11 and the middle case member 12 by the support members 17-19.

A battery control device 20 for controlling the battery pack 3 is disposed above the upper module 16, and the battery control device 20 is fixed to the middle case upper surface 12a via a mounting bracket 20a. In order to block or reduce electromagnetic waves (noise) emitted by the battery control device 20, the upper case member 13 is covered from above so as to cover a predetermined area of the middle case upper surface portion 12a including the battery control device 20 and the upper module 16, It is fixed to the middle case upper surface portion 12a by bolts (not shown) or the like. Although not shown, the middle case upper surface 12a is provided with an opening through which a bus bar connecting the lower module 15 and the upper module 16 is inserted. there is

The upper module 16 is watertightly accommodated by the upper case member 13 and the middle case member 12 so as to be in close contact with the middle case upper surface 12 a and not to contact the upper case member 13 . The middle case member 12 radiates the heat transferred from the upper module 16 to the outside by heat radiation, running wind, or the like. A sealing member 12f is provided between the upper case lower surface portion 13c and the middle case upper surface portion 12a to prevent water from entering. It is preferable that the sealing member 12f has electrical conductivity for good conduction between the upper case member 13 and the middle case member 12. As shown in FIG.

In the panel portion 11b of the middle case member 12 and the lower case member 11, the surface portions exposed to the outside are subjected to a treatment such as anti-corrosion treatment to prevent scratches due to collision of pebbles or the like. This surface treatment is also a surface treatment that reduces the reflectance of infrared rays (heat) on the surface in order to increase the emissivity based on Kirchhoff's radiation law. For example, if the panel portion 11b of the middle case member 12 and the lower case member 11 is made of aluminum alloy, the exposed surface portion is anodized to improve corrosion resistance and infrared (heat) emissivity.

The upper module 16 is arranged at a position higher than the lower module 15 in the rear portion of the middle case upper surface portion 12a. The upper case member 13 that accommodates the upper module 16 protrudes upward from the middle case upper surface portion 12a. On the other hand, the rear portion of the floor panel 4 of the passenger compartment is formed higher than the front portion, and a rear seat 10 is provided thereon.

Below the rear portion of the floor panel 4 formed high, an upper case member 13 projecting above the middle case upper surface portion 12a is arranged, and below the front portion of the floor panel 4, a middle case member 13 is arranged. Twelve front portions are provided. Accordingly, the battery pack 3 is mounted on the vehicle 1 using the space below the floor panel 4 according to the shape of the floor panel 4 .

Next, functions and effects of the present invention will be described.
The battery mounting structure of the vehicle 1 arranges the battery pack 3 below the floor panel 4 of the passenger compartment. The battery pack 3 has a case 8 composed of a lower case member 11, a middle case member 12, and an upper case member 13, and accommodates a plurality of battery modules M1 to M16 in the case 8 watertightly. The vehicle 1 runs using the electric power stored in the battery modules M1 to M16, and the case 8 protects the battery modules M1 to M16 from damage and the like by preventing collisions with pebbles and flooding during running.

The battery pack 3 has a plurality of battery modules M1 to M16 stacked vertically in two stages to increase the number of battery modules to be mounted. In order to release the heat of the upper module 16 to the outside of the case 8 , the upper module 16 is brought into close contact with the metallic middle case upper surface 12 a to transfer the heat to the middle case member 12 . Since the middle case member 12 radiates heat to the outside by thermal radiation, running wind, etc., the upper module 16 housed in the case 8 in a watertight manner can be cooled. Since no electric power is used for cooling the battery modules M1 to M16 at this time, the amount of stored electricity does not decrease.

An upper case member 13 projecting upward from the middle case member 12 is arranged below the rear portion of the floor panel 4 formed higher than the front portion of the floor panel 4 of the passenger compartment. Accordingly, the space below the floor panel 4 can be used to match the shape of the floor panel 4 to increase the number of installed battery modules without narrowing the passenger compartment.

Under the upper module 16, a plurality of support members 17 to 19 support the middle case upper surface 12a of the middle case member 12, thereby restricting the downward deflection of the middle case member 12 due to the weight of the upper module 16. there is Therefore, contact between the middle case member 12 and the lower module 15 can be prevented to prevent problems such as short circuits.

In addition, those skilled in the art can implement various modifications to the above embodiment without departing from the scope of the present invention, and the present invention includes such modifications.

Reference Signs List 1: Vehicle 2: Electric motor 3: Battery pack 4: Floor panel 5: Floor frame 6: Cross member 8: Case 10: Rear seat 11: Lower case member 12: Middle case member 12a: Middle case upper surface 13: Upper case Member 13c: Lower surface of upper case (peripheral edge)
15: lower module 16: upper module 17-19: support member 20: battery control device 21: storage batteries M1-M16: battery module

Claims (2)

In a vehicle battery mounting structure provided with a case for housing a plurality of battery modules for driving the vehicle under the floor panel of the vehicle compartment,
the plurality of battery modules are divided into a lower module and an upper module,
The case has a lower case member made of metal, a middle case member made of metal, and an upper case member for covering a predetermined region of the upper surface of the middle case member from above,
The lower module is fixed to the bottom of the lower case member,
the middle case member is fixed to the lower case member so as to cover the lower module from above, and the lower module is housed in a watertight manner;
the upper module is fixed in a state of being in close contact with the upper surface of the middle case member within the predetermined area;
The upper case member is formed in the shape of a container having an opening at the bottom, covers the predetermined area, and is fixed in a state in which the peripheral edge of the opening is in close contact with the upper surface of the middle case member. is housed watertight,
The case is fixed to the vehicle by attaching the lower case member to the lower side of the floor panel ,
The rear portion of the floor panel is formed higher than the front portion,
A battery mounting structure for a vehicle , wherein the upper case member is arranged below the rear portion . In a vehicle battery mounting structure provided with a case for housing a plurality of battery modules for driving the vehicle under the floor panel of the vehicle compartment,
the plurality of battery modules are divided into a lower module and an upper module,
The case has a lower case member made of metal, a middle case member made of metal, and an upper case member for covering a predetermined region of the upper surface of the middle case member from above,
The lower module is fixed to the bottom of the lower case member,
the middle case member is fixed to the lower case member so as to cover the lower module from above, and the lower module is housed in a watertight manner;
the upper module is fixed in a state of being in close contact with the upper surface of the middle case member within the predetermined area;
The upper case member is formed in the shape of a container having an opening at the bottom, covers the predetermined area, and is fixed in a state in which the peripheral edge of the opening is in close contact with the upper surface of the middle case member. is housed watertight,
The case is fixed to the vehicle by attaching the lower case member to the lower side of the floor panel,
A battery for a vehicle , wherein a plurality of metal support members for supporting the middle case member are disposed between the lower case member and the middle case member below the upper module. mounting structure.

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