JP2013246920A - Battery cooling structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery cooling structure which can suppress spread of damage of fire even when the battery is ignited, in an air-cooled battery pack cooling structure.SOLUTION: A battery pack 1 consisting of a plurality of single cells 11 is housed in a housing 2 provided with a suction port 22 for introducing the cooling air thereinto and an exhaust port 21 for exhausting the cooling air, and the battery pack is cooled by the cooling air. The single cell 11 is a lithium ion secondary battery or a nickel-hydrogen secondary battery. A fireproof closing member 3, which expands with heat upon occurence of fire and closes the suction port or exhaust port, is provided at the suction port 22 or exhaust port 21. The fireproof closing member 3 is composed of a thermal expansion fireproof resin material containing an expansion material having an expansion start temperature of 270°C or lower.

Description

The present invention relates to a cooling structure for a battery. In particular, the present invention relates to a battery cooling structure in which an assembled battery in which a plurality of secondary batteries are combined is housed in a casing and the assembled battery is cooled by cooling air.

An assembled battery in which a plurality of secondary batteries such as nickel metal hydride batteries and lithium ion batteries are combined is used in various industrial fields. For example, the assembled battery is used for power source and energy regeneration of a hybrid vehicle, an electric vehicle, a fuel cell vehicle, and the like. The assembled battery may also be used for power storage for the purpose of load leveling of system power, emergency power storage, and the like. Since the assembled battery using these secondary batteries generates heat during charging or discharging, it is cooled to maintain the battery temperature. For example, in the case of an assembled battery for an automobile, a battery cooling structure for air-cooling the assembled battery with cooling air is often adopted.

For example, Patent Document 1 discloses a cooling structure for a vehicle battery pack, wherein the battery pack includes a battery unit including a battery module and an electrical part attached to the battery unit. A battery pack cooling structure comprising: a flow passage for flowing a cooling medium in parallel with the battery portion and the accessory portion; and a cooling fan for flowing the cooling medium in the flow passage. According to the battery pack cooling structure, it is disclosed that the battery and the electric device attached to the battery can be efficiently cooled.

JP 2004-306726 A

By the way, as the capacity and density of the assembled battery increase, the battery itself may become high temperature depending on use conditions. When the battery temperature becomes abnormally high, flammable gas may be emitted from the battery that has become hot, leading to ignition. When the battery ignites, flames and high-temperature gas may flow through the duct that sent the cooling air, damaging surrounding members and spreading the fire.

An object of the present invention is to provide a battery cooling structure capable of suppressing the expansion of fire damage even when a battery ignites in an air-cooled assembled battery cooling structure.

As a result of intensive studies, the inventor has arranged a fireproof closing member that expands due to heat at the time of a fire and closes the intake or exhaust port at the cooling air intake or exhaust port of the assembled battery case, and cools it in the event of a fire. The present invention has been completed by discovering that the above object can be achieved by blocking the air passage.

In the present invention, an assembled battery including a plurality of single cells is accommodated in a housing, and the housing has an intake port for introducing cooling air into the housing and an exhaust port for discharging the cooling air. A battery cooling structure that is provided and cools the assembled battery with cooling air, and the unit cell is a lithium ion secondary battery or a nickel metal hydride secondary battery, and the intake port or the exhaust port expands due to heat at the time of fire And a fire-resistant closing member that closes the intake port or the exhaust port is disposed, and the fire-resistant closing member is made of a thermally expandable refractory resin material containing an expansion material having an expansion start temperature of 270 ° C. or less. (First invention).

In the present invention, a duct member is connected to the intake port or the exhaust port, and the fireproof blocking member has a cylindrical portion arranged along the peripheral surface of the intake port or the exhaust port, and the fireproof blocking member It is preferable that the cylindrical portion is interposed between the intake port or the exhaust port and the duct member (second invention). In the present invention, it is preferable that the assembled battery is an assembled battery mounted on an automobile, and a duct communicating with the vehicle interior is connected to the intake port, and a fireproof closing member is disposed at the intake port ( Third invention). Further, in the present invention, the fireproof closing member is a member provided with a cooling air passage through which the cooling air flows, and the cooling airflow direction of the fireproof closing member is larger than the dimension in the width direction of the cooling air passage. It is preferable that the length dimension along is increased (fourth invention). Moreover, in this invention, it is preferable that an expansion | swelling material contains a thermally expansible graphite (5th invention).

According to the battery cooling structure of the present invention (first invention), when a fire occurs, the fireproof closing member expands due to heat and closes the inlet or outlet, so that even if the battery ignites, Damage expansion can be suppressed.

Furthermore, in the second invention, it is possible to effectively suppress a problem that high temperature gas or flame leaks from a gap between the connection portion between the intake port and the exhaust port and the duct, and it is possible to effectively suppress the expansion of fire damage. Further, in the third invention, it is possible to suppress fire smoke from flowing into the passenger compartment. According to the fourth and fifth inventions, the cooling air passage can be more effectively closed by the fireproof closing member.

It is a perspective view showing the whole battery cooling structure composition of a 1st embodiment of the present invention. It is a perspective view which shows the structure of the assembled battery periphery of the battery cooling structure of 1st Embodiment. It is a perspective view which shows the example of a form of a fireproof obstruction | occlusion member. It is sectional drawing which shows the example of the connection structure of an air inlet and an air intake duct. It is the front view and sectional drawing which show the other example of a fireproof closure member. It is the front view and sectional drawing which show the further another example of a fireproof closure member. It is the front view and side view which show the further another example of a fireproof closure member. It is sectional drawing which shows the other example of the connection structure of an air inlet and an air intake duct.

Hereinafter, embodiments of a battery cooling structure of the present invention will be described with reference to the drawings, taking as an example a battery cooling structure for cooling a battery pack for a hybrid vehicle. FIG. 1 is a perspective view of a first embodiment of a battery cooling structure of the present invention. FIG. 2 is a perspective view showing a configuration around the assembled battery of the battery cooling structure of the present embodiment. In these drawings, the detailed configuration of the battery such as a gas discharge valve and a bus bar provided in the unit cell is not shown. In addition, this invention is not limited to the separate embodiment shown below, The form can also be changed and implemented.

In an assembled battery structure (hereinafter simply referred to as “assembled battery”) 1, flat unit cells 11, 11 constituting the assembled battery are spaced apart from each other by a predetermined distance so that the wide surfaces of the unit cells face each other. They are arranged in a stacked state with a gap therebetween. The unit cells 11 and 11 are electrically connected in series or in parallel by a bus bar (not shown) to constitute an assembled battery. In the present embodiment, the single battery 11 constituting the battery module is a lithium ion secondary battery. The lithium ion secondary battery may be a lithium ion polymer battery. The unit cell 11 has a flat plate shape (flat rectangular parallelepiped shape). Electrode terminals are provided on the side surfaces (surfaces adjacent to a wide flat surface) of each battery. The single battery may be a nickel metal hydride battery. The present invention is applicable to an assembled battery using a single battery operated at room temperature.

The assembled battery 1 is accommodated in a rectangular parallelepiped casing 2. In FIG. 1, a part of the upper surface of the housing is shown, and in FIG. 2, the entire upper surface of the housing is not shown, and the arrangement of the assembled battery 1 inside the housing is visible. The housing 1 preferably includes a non-flammable material such as a metal material (for example, a galvanized steel plate) or a flame retardant material (for example, a flame retardant resin material) in order to improve fire resistance against battery fire. Composed.

The casing 2 is provided with a hollow cylindrical intake port 22 and exhaust ports 21 and 21. Cooling air is introduced into the housing 2 through the intake port 22, and cooling air is discharged from the housing through the exhaust ports 21 and 21. Inside the housing 2, the cooling air flows through the gaps between the single cells 11, 11 to cool the assembled battery 1 (each single cell 11).

In the present embodiment, the intake duct 52, the blower fan F, and the intake duct 51 are connected in order on the upstream side of the intake port 22. Air is sucked from the front end portion of the intake duct 51 by the blower fan F, and cooling air is sent to the intake port 22 through the intake duct 52. Although not connected in the present embodiment, an exhaust duct (not shown) may be connected to the exhaust ports 21 and 21 so that the cooling air is guided to a predetermined position and then discharged.

In a hybrid vehicle or the like, such an assembled battery and a battery cooling structure are often arranged, for example, behind a rear seat or in a trunk room so as to take in cooling air from the vehicle interior or the trunk room.

In the battery cooling structure of the present embodiment, the fireproof blocking members 3, 3 are disposed inside the intake port 22 and the exhaust ports 21, 21. FIG. 3 is a perspective view showing a form of the fireproof closing member 3 in the present embodiment. FIG. 4 is a cross-sectional view showing a state in which the fireproof closing member 3 is arranged at the connection portion between the intake port 22 and the intake duct 52.

The fireproof blocking member 3 can be attached to the inside of the intake port 22 and the exhaust ports 21 and 21 by a known means. For example, the fireproof closing member 3 can be fixed by means such as adhesion, fitting, adhesive material, and locking claws. It is preferable to fix and attach the fireproof closing member 3 by these means so that the fireproof closing member 3 does not move due to vibration or the like.

As shown in FIG. 3, the fireproof closing member 3 has a hollow frame shape. That is, the fire-resistant closing member 3 is a hollow frame-like (short cylindrical) member having a predetermined thickness and a predetermined length along the inner peripheral surface shape of the hollow cylindrical intake port 22 and the exhaust port 21. is there. When the fireproof closing member 3 is attached to the intake port 22 or the exhaust port 21, cooling air flows through the hollow portion of the fireproof closing member 3 in normal times (when no fire is generated).

From the standpoint that the flow of the cooling air during normal operation is not hindered and can be reliably attached to the intake port or the exhaust port, the entire or at least a part of the refractory blocking member 3 is made into the intake port or the exhaust port as in this embodiment. It is preferable to arrange it along the inner peripheral surface of the duct.

The fireproof closing member 3 is made of a heat-expandable fireproof resin material described later. When a fire occurs in the assembled battery 1, the fireproof closing member 3 expands due to heat and closes the intake port 22 and the exhaust port 21. The specific shape and dimensions of the fireproof closing member 3 are determined so that the cooling air passage is reliably closed by expansion. In the present embodiment, the entire fireproof closing member 3 is formed of a thermally expandable fireproof resin material. In addition, the fireproof closing member may include a reinforcing body other than the thermally expandable fireproof resin material.

Hereinafter, the heat-expandable fireproof resin material constituting the fireproof closing member 3 will be described. The heat-expandable refractory resin material is a resin composition in which a resin material (base material) and an expansion material are mixed or kneaded as main components. The thermally expandable refractory resin material is preferably a resin material having elasticity. When the heat-expandable refractory resin material is heated, the expansion material expands and the volume increases. Further, the expanded thermally expandable refractory resin material has fire resistance. That is, the expanded thermally expandable refractory resin material has a flame retardance or nonflammability that does not burn for a predetermined time even if exposed to a flame. The heat-expandable refractory resin material is preferably a material that is carbonized after being heated and expanded.

As a resin material which becomes a base material of the thermally expandable refractory resin material, a resin (particularly a thermoplastic resin), rubber or elastomer (particularly a thermoplastic elastomer) is preferably used. For example, butadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, natural rubber, isoprene rubber, ethylene propylene rubber, butyl rubber, acrylic rubber, urethane rubber, silicone rubber, fluorine rubber, thermoplastic elastomer (olefin-based thermoplastic elastomer, urethane-based heat) Examples thereof include plastic elastomers, acrylic thermoplastic elastomers, particularly styrene thermoplastic elastomers), olefin resins (α-olefin copolymers, ethylene copolymers, etc.), and the like. The resin material is preferably elastic. Olefin resins such as polyethylene are particularly preferred because they do not generate toxic gases during heating and combustion. You may use the said resin material individually or in mixture as appropriate.

In addition to the above resin materials, other resin materials such as polyester resins, polycarbonate resins, polystyrene resins, acrylic resins, acrylonitrile styrene butadiene resins, polyamide resins, epoxy resins, phenol resins, etc. May be mixed. Moreover, it can also be used as a base material of a thermally expansible refractory resin material by making these resin materials into a main body. Since the phenolic resin is cured and carbonized by heating, when the phenolic resin is mixed as a resin material, it is prevented that the fireproof closing member 3 is easily softened, deformed or dropped when heated, and the fireproof closing member 3 is maintained at the initial position, and is effective in effectively closing the cooling air passage. The resin material is preferably a resin that does not contain a liquid component.

Examples of the expansion material kneaded with the resin material include expansion materials that expand by heating, such as inorganic expansion materials such as thermally expandable layered inorganic materials and obsidian, and organic expansion materials such as expandable nitrogen compounds and expandable microcapsules. Can be used. Examples of the thermally expandable layered inorganic material include vermiculite, carion, mica, and thermally expandable graphite. An inorganic expansion material is particularly preferable because it has nonflammability or flame retardancy.

Among them, it is preferable to use thermally expandable graphite as the expansion material because the expansion ratio of the resin composition can be increased and the expansion start temperature can be easily controlled. Thermally expandable graphite is a known crystalline compound in which graphite powder is treated with an inorganic acid and a strong oxidizing agent to produce a graphite intercalation compound, and maintains a layered structure of graphite. In particular, a neutralized product is preferably used so as not to react with a phosphorus compound described later. Graf Guard (manufactured by Ucar Carbon) can be exemplified as a commercial product of the heat-expandable graphite that has been neutralized.

The expansion start temperature of the expansion material is 100 ° C. or higher and 270 ° C. or lower, more preferably 120 ° C. or higher and 240 ° C. or lower, and particularly preferably 140 ° C. or higher and 200 ° C. or lower. When the expansion temperature is high, the cooling air passage is blocked more slowly. If the expansion start temperature is low, foaming may occur during the kneading of the thermally expandable refractory resin material, or expansion may occur when there is no fire. In addition, you may mix | blend combining the expansion | swelling material which starts expansion | swelling at comparatively low temperature (for example, 220 degreeC), and the expansion | swelling material which starts expansion | swelling at comparatively high temperature (for example, 400 degreeC).

A preferable expansion ratio of the expansion material is 2.5 to 400 times, more preferably 5 to 150 times in terms of volume expansion coefficient.

In the fireproof closing member 3 of the present embodiment, a thermoplastic elastomer is used as a base material of a resin material, thermally expandable graphite is blended as an expandable material, and these materials are kneaded to form a thermally expandable fireproof material.
In addition to the heat-expandable refractory resin material, the following can be appropriately added as necessary.

Adding phosphorus compounds (phosphorous flame retardants) such as red phosphorus, phosphate esters, metal phosphates, and ammonium polyphosphates can increase the flame retardancy of thermally expandable fire-resistant resin materials and improve fire resistance. it can. Addition of ammonium polyphosphate is particularly preferable.

When a hydrous inorganic substance such as aluminum hydroxide or magnesium hydroxide is added, a dehydration reaction occurs during heating, and the heat resistance of the thermally expandable refractory resin material can be improved by the endothermic action of the generated water.

In addition, inorganic fibers such as basalt fibers and glass fibers, and organic fibers such as aramid fibers and carbon fibers can be added to the thermally expandable refractory resin material as a filler. By adding the fiber material to the thermally expandable refractory resin material, it is possible to adjust the expansion rate and expansion ratio when the thermally expandable refractory resin material expands. The fiber material is preferably nonflammable or flame retardant. The fiber material preferably has heat resistance at a temperature higher than the expansion start temperature of the expansion material.

In addition to the heat-expandable refractory resin material, a heat stabilizer, a processing aid, a lubricant, and the like may be blended.

Moreover, when it is desired to impart adhesiveness at room temperature to the thermally expandable fireproof resin material, it is possible to impart adhesiveness to the surface of the fireproof blocking member 3 by adding an adhesive component such as a tackifier. It is preferable to select a tackifier or oligomer to be added that is compatible with the base resin material.

In order to give the fireproof blocking member 3 appropriate elasticity, it is preferable that the degree of elasticity of the heat-expandable fireproof resin material is 50 MPa to 1000 MPa as a flexural modulus according to JIS K 7171. In particular, when a part of the fire-resistant closing member is interposed between the intake port or the exhaust port and the duct member as in the embodiment of FIG. 8 described later, the bending elastic modulus of the thermally expandable fire-resistant resin material is used. Is preferably 100 MPa to 500 MPa, and by doing so, it is easy to maintain the connection between the intake port or the exhaust port and the duct member by the interposed fireproof blocking member, and the seal between the connecting members You can also do it.

The preferable range of the volume expansion coefficient during heating of the heat-expandable refractory resin material in the present invention is 3 to 40 times, and more preferably 5 to 20 times. If the expansion ratio is low, a large amount of heat-expandable refractory resin material is required to close the cooling air passage, which is uneconomical. Will become bigger. On the other hand, if the expansion ratio is too high, the expanded refractory material is likely to dissipate, which may make it difficult to block the cooling air passage.

The volume expansion coefficient of the heat-expandable refractory resin material should be adjusted by adjusting the blending ratio of the expanding material, the viscosity of the resin material at the temperature at which the expanding material expands, and the blending amount of the filler (particularly the fiber material). Can do. In particular, when a fiber material is blended, the fiber material is highly constrained at the time of expansion, so the expansion ratio can be suppressed without reducing the blending amount of the expansion material, and it has excellent shielding effects such as flame, and retains its shape after expansion. It is easy to obtain a highly heat-expandable refractory resin material, which is preferable.

The above heat-expandable refractory resin material prepared and kneaded is fire-resistant using molding methods suitable for the base resin material, such as extrusion molding, injection molding, roll molding (calender molding), press molding and blow molding. It is formed in the shape of the closing member 3. According to the extrusion molding method, the heat-expandable refractory material can be directly extruded into a tube shape and cut into a predetermined length to form the short tube-shaped refractory molded body 3. When the shape of the fireproof closing member 3 is complicated, it is preferable to use injection molding or press molding.

The operation and effect of the battery cooling structure of the embodiment will be described. Since the fire-resistant closing member 3 normally does not block the cooling air passage, a predetermined amount of cooling air can be passed. On the other hand, when a fire occurs in the assembled battery 1, the fireproof blocking member 3 provided at the intake port 22 or the exhaust port 21 expands due to heat or flame due to the fire and closes the cooling air passage.

Then, the hot gas and flame no longer go beyond the intake port 22 and the exhaust port 21, so that damage to members in such a place and the spread of fire can be suppressed. Further, if the fireproof closing member 3 provided at the intake port 22 or the exhaust port 21 expands and closes the cooling air passage, the cooling air flow stops, so that new air is no longer supplied inside the housing, and the housing Combustion of combustible substances inside is suppressed, and the expansion of fire inside the housing can also be expected.

In the above-described embodiment, the embodiment in which the fireproof blocking member 3 is provided in both the intake port 22 and the exhaust port 21 has been described, but it is not necessarily provided in both the intake port and the exhaust port. Even if only one of them is provided, an effect of suppressing the expansion of the fire can be expected if the cooling air flow can be stopped.

It is preferable to provide the fireproof closing member 3 on the exhaust port 21 side. In the air cooling type battery cooling structure using cooling air, the air inside the battery case 2 is exhausted from the exhaust port 21 to the outside of the case. Therefore, if the fireproof closing member 3 is provided on the exhaust port 21 side, the case Even if the battery ignites somewhere inside, when the high-temperature combustion gas reaches the exhaust port 21, the fireproof closing member 3 starts to expand and closes the exhaust port. At the stage, the expansion of fire damage can be suppressed.

In addition, when the assembled battery is mounted on an automobile and a series of intake ducts connected to the intake port are provided so as to communicate with the passenger compartment (occupant room), the fireproof closing member 3 is disposed at the intake port. It is preferable. By doing so, even if a fire occurs in the assembled battery, it is possible to suppress the smoke and hot air from flowing into the passenger compartment.

The present invention is not limited to the above embodiment, and can be implemented with various modifications. Other embodiments of the present invention will be described below, but in the following description, the description will focus on parts different from the above-described embodiments, and the same parts (with the same numbers) will be described in detail. Omitted. Further, the embodiments described below can be implemented by combining some of them or replacing some of them.

5 and 6 show examples of other embodiments of the fireproof closing member. The fireproof closure members of these embodiments are the same as the fireproof closure members of the first embodiment in that the entire fireproof closure members are integrally formed of a thermally expandable fireproof material, but the shapes thereof are different. .

In the fireproof blocking member 4 of the second embodiment shown in FIG. 5, a cooling air passage inside the cylinder portion 41 is connected to a rectangular tube-shaped cylinder portion 41 to be disposed along the inner peripheral surface of the intake port or the exhaust port. A grid-like partition portion 42 is integrated so as to partition the two. The partition portion 42 divides the cooling air passage inside the fireproof closing member 4 into thin pieces, so that it is easily closed when heated and expanded.

Further, in the present embodiment, the length (the length in the direction along the cooling air flow) L of the fireproof closing member 4 is made larger than the representative dimension H inside the cylindrical portion 41. Thus, when the length dimension (L) along the cooling air flow direction of the fireproof blocking member is longer than the dimension (H) in the width direction of the cooling wind passage provided inside the fireproof blocking member, When the fireproof closing member 4 is heated and expanded, the cooling air passage can be closed more reliably.

In the fireproof closing member 8 of the third embodiment shown in FIG. 6, a plate-shaped partition is formed so as to partition the inside of the rectangular tube-shaped cylinder portion 81 that should be disposed along the inner peripheral surface of the intake port or the exhaust port. The parts 82 and 82 are arranged in parallel with a predetermined distance d and are integrally formed.
Further, in the present embodiment, the length (the length in the direction along the cooling air flow) L of the fireproof blocking member 8 is made larger than the distance d at which the plate-like partition portions 82 and 82 are separated. Yes. Thus, when the length dimension (L) along the cooling air flow direction of the fireproof blocking member is longer than the dimension (d) in the width direction of the cooling wind passage provided inside the fireproof blocking member, When the fireproof closing member 8 is heated and expanded, it is particularly easily blocked. When the cooling air passage has an elongated cross-sectional shape as in this embodiment, the dimension in the width direction of the cooling air passage is a length corresponding to the side or diameter on the short side of the passage cross-sectional shape (this embodiment In other words, the above-described effect can be obtained if the length L of the fireproof closing member is increased with reference to d).

The fire-resistant closing members 4 and 8 shown in FIG. 5 and FIG. 6 can be manufactured by using extrusion molding and once forming a continuous cylinder into a predetermined length. Or these fireproof closure members 4 and 8 can also be formed by injection molding.

The fireproof closing member is not limited to the cylindrical shape as described above. For example, a fireproof blocking member formed into a plate shape may be arranged and fixed along a part of the inner peripheral surface of the intake port or the exhaust port. For example, a flat fireproof blocking member may be attached to a surface corresponding to the long side of a rectangular tube-shaped intake port having a rectangular cross section.

Or as shown in FIG. 7, you may integrate a heat-expandable fireproof resin material with support members, such as a metal-mesh, and may comprise a fireproof closure member. In the embodiment shown in FIG. 7, the lattice-shaped wire mesh 61 is used as a support member, and the surface of the metal wire constituting the wire mesh is integrated so as to coat the heat-expandable refractory resin material 62, so A member 6 is configured. In FIG. 7, the wire mesh 61 is indicated by a thick solid line, and the portion coated with the heat-expandable fireproof resin material 62 is indicated by a thin wavy line. The fireproof closing member 6 still leaves the gap that the wire mesh 61 as the support member has, and the cooling air can flow through the gap. If the fireproof closing member 6 is attached so as to block the intake port and the exhaust port, the same operations and effects as the above embodiment can be exhibited.

In particular, in this embodiment, since the heat-expandable refractory resin material can be disposed uniformly over the entire cross section of the intake port and the exhaust port, the cooling air passage can be easily blocked at an earlier stage of the fire.

Further, when the thermally expandable refractory resin material 62 is integrated only on one side of the wire mesh 61 as in the present embodiment, the side where the thermally expandable refractory resin material is unevenly distributed faces the inside of the housing 2. It is preferable to arrange the fire-resistant closing member 6 in the position. In this way, the thermally expandable refractory resin material can be expanded at an earlier timing. Or it is preferable to arrange | position the fireproof obstruction | occlusion member 6 so that the side where a thermally expansible fireproof resin material is unevenly distributed may face the upstream of a cooling wind flow. In this way, even if the expanded heat-expandable refractory resin material is somewhat brittle, it can be caught by the downstream metal mesh and the cooling air passage can be effectively blocked.

As shown in the above embodiment, the fireproof closing member may have a support member (reinforcing body) made of a material having high heat resistance such as metal. The support member may be formed of a metal plate, a thermosetting resin member, or the like in addition to the metal mesh. For example, it is also a preferred embodiment to provide a support member (reinforcing body) in the partition portion of the fireproof closing members 4 and 8 shown in FIGS.

FIG. 8 shows still another embodiment. The fireproof closing member 7 in the present embodiment is entirely formed in a cylindrical shape. And the one end side of the fireproof closure member 7 is the cylindrical part 71 formed thinner than the other end side. In the present embodiment, a duct member 52 is connected to the intake port 22. The duct member 52 and the intake port 22 are inserted and connected so as to overlap each other. The fireproof blocking member 7 is disposed along the circumferential surface of the duct member or the intake port. The cylindrical portion 71 of the fireproof closing member 7 is interposed between the air inlet 22 and the duct member 52.

Thus, if the cylindrical part 71 provided in the fireproof closing member 7 is interposed between the intake port 22 and the duct member 52, the cylindrical part 71 expands when a fire occurs. It works so as to close the gap between the connecting portions, and the leakage of flames and hot air from the connecting portion between the intake port and the duct member is effectively suppressed.

When interposing the part 71 of the fireproof closing member 7 in the part where the air inlet 22 and the duct 52 are fitted so as to overlap each other as in the present embodiment, the thermally expandable fireproof resin material is used. It is preferable that a rubber material or an elastomer material is included to make the material rich in elasticity.

If the part 71 of the fireproof blocking member 7 to be interposed is rich in elasticity, the connection between the duct 52 and the air inlet 22 can be maintained well, and the connection portion of both can be sealed. Moreover, in order to improve a sealing performance, it is preferable to form a lip | rip and a bead in the part 71 where the fireproof closure member is inserted.

In addition, even if it is a case where a part of the fireproof closing member is interposed in the connection portion such as a duct as in the embodiment shown in FIG. 8, it is not always necessary to make the entire fireproof closing member rich in elasticity. The fire-resistant closing member may be formed by two-color molding so that only the interposed portion is formed of a material having high elasticity.

In addition, as an example of another form of the fireproof closing member having a cylindrical interposed portion, a portion where the fireproof closing member 7 illustrated in FIG. 8 is not interposed is folded inside the intake port 22. Examples include a configuration in which the end portions of the intake port and the exhaust port are covered and the thermally expandable refractory resin material is disposed in a cylindrical shape inside and outside the intake port and the exhaust port. If it is set as the fireproof closure member of such a form, it becomes easy to attach a fireproof closure member to the housing | casing 2, and is preferable.

Moreover, when a filter member is attached to the battery housing inlet 22 side, the frame portion of the filter member can be made of the above-described thermally expandable fire-resistant resin material, and the frame portion of the filter member can be a fire-resistant closing member. .

The battery cooling structure of the present invention can be applied to a battery cooling structure of an assembled battery operated at normal temperature (particularly in a temperature range of −50 ° C. to 100 ° C.). Examples of the secondary battery constituting the assembled battery include a lithium ion secondary battery, a nickel hydride secondary battery, and a nickel cadmium secondary battery.

The purpose and application for which the assembled battery is used are not limited to those for automobiles. For example, a secondary battery is used for the purpose of leveling generated power in a wind power generator or a solar battery power generator. The present invention can be utilized for assembled batteries used in a wide range of applications.

INDUSTRIAL APPLICABILITY The present invention can be used for cooling large-capacity assembled batteries used in electric vehicles, hybrid vehicles, power generation devices, and the like, and has high industrial utility value.

DESCRIPTION OF SYMBOLS 1 Assembly battery 11 Cell 2 Case 21 Exhaust port 22 Inlet port 3 Fireproof closing member 51,52 Intake duct F Blowing fan 4,6,7,8 Fireproof closing member 41,81 Cylindrical part 42,82 Partition part 61 Wire net 62 Thermally expandable refractory resin material

Claims (5)

An assembled battery made up of a plurality of single cells is housed inside the housing, and the housing is provided with an intake port for introducing cooling air into the housing and an exhaust port for discharging cooling air. A battery cooling structure for cooling the battery pack by wind,
The cell is a lithium ion secondary battery or a nickel hydride secondary battery,
At the intake or exhaust port, there is a fire-resistant closing member that expands due to heat at the time of the fire and closes the intake or exhaust port,
The battery-cooling structure in which the fireproof closing member is made of a thermally expandable fireproof resin material including an expansion material having an expansion start temperature of 270 ° C. or lower. A duct member is connected to the intake or exhaust port,
The fireproof blocking member has a cylindrical portion arranged along the peripheral surface of the intake port or the exhaust port,
The battery cooling structure according to claim 1, wherein the cylindrical portion of the fireproof closing member is interposed between the intake port or the exhaust port and the duct member. The assembled battery is an assembled battery installed in an automobile,
The battery cooling structure according to claim 1 or 2, wherein a duct communicating with the passenger compartment is connected to the air intake and a fireproof closing member is disposed at the air intake. The fireproof blocking member is a member provided with a cooling air passage through which cooling air flows.
The battery cooling structure according to any one of claims 1 to 3, wherein a length of the fireproof blocking member along a cooling airflow direction is longer than a widthwise dimension of the cooling air passage. The battery cooling structure according to any one of claims 1 to 4, wherein the expansion material contains thermally expandable graphite.

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