JP2022094722A - Battery pack structure - Google Patents

Abstract

To provide a battery pack structure capable of suppressing damage to a housing due to heat from released gas without providing a separate member.SOLUTION: In a battery pack structure, a deflection surface that deflects the flow of gas discharged from a discharge port to the outside of a facing region is provided in a region facing a gas discharge port of a battery cell on the inner surface of a housing.SELECTED DRAWING: Figure 4

Description

The present invention relates to a battery pack structure.

Patent Document 1 is provided on the upper surface of the outer case so as to insulate between a safety valve that breaks when the pressure inside the battery cell becomes an abnormal pressure and the bus bar and the outer case, and at least cover the upper surface portion of the outer case excluding the safety valve. A cover portion provided and a smoke exhaust duct having an inner wall surface facing the safety valve so as to expose the heat-resistant safety valve not covered by the cover portion to the smoke exhaust passage formed inside. , Multiple voltage detection lines extending from terminals electrically connected to multiple battery cells to obtain information on the status of multiple battery cells are bundled and placed above the smoke exhaust duct for wiring. It discloses a cable and a battery pack with.

Japanese Unexamined Patent Publication No. 2012-113896

In the structure of the battery pack, in order to induce and discharge the gas released from the safety valve, it is necessary to provide a smoke exhaust duct that is a separate member from the housing, which increases the weight and cost of the battery pack. The degree of freedom in design was reduced.

An object of the present invention is to provide a battery pack structure capable of suppressing damage to a housing due to heat from emitted gas without providing a separate member.

In the battery pack structure according to one aspect of the present invention, the deflection of the gas discharged from the discharge port to the opposite region facing the gas discharge port of the battery cell on the inner surface of the housing is deflected to the outside of the facing region. A surface is provided.

According to the battery pack structure, damage to the housing due to heat from the released gas can be suppressed without providing a separate member.

It is an overall perspective view of the battery pack which concerns on embodiment. It is a developed perspective view of the battery pack which concerns on embodiment. It is a perspective view of the battery module which concerns on embodiment. FIG. 1 is a cross-sectional view taken along the line IV-IV of FIG. 1, showing a deflection surface provided on the inner surface of the housing and a battery cell discharge port. It is an arrow view along the VV line of FIG. It is sectional drawing corresponding to FIG. 4 which shows the deflection surface and the discharge port which concerns on 2nd Embodiment. FIG. 6 is an arrow view taken along the line VII-VII of FIG. It is sectional drawing corresponding to FIG. 4 which shows the deflection surface and the discharge port which concerns on 3rd Embodiment. It is an arrow view along the IX-IX line of FIG.

Hereinafter, the battery pack structure according to some embodiments will be described with reference to the drawings. In each figure, FR and RR indicate the front and the rear in the vehicle front-rear direction, LH and RH indicate the left and right in the vehicle width direction, and UP and DN indicate the upper and lower directions in the vehicle vertical direction, respectively. In the following description, the front and rear of the vehicle in the front-rear direction, the upper and lower parts in the vertical direction of the vehicle are simply referred to as "front", "rear", "upward" and "downward", respectively. Further, elements having the same function are designated by the same reference numerals, and duplicate description will be omitted.

<First Embodiment>
The battery pack P according to the first embodiment is a storage battery (secondary battery) mounted on an electric vehicle such as an electric vehicle (EV) or a hybrid vehicle (HV) and used as a drive power source for the vehicle. As shown in FIG. 1, the battery pack P has a flat shape in which the vertical dimension of the vehicle is smaller than the dimension in the front-rear direction of the vehicle and the vertical dimension of the vehicle is smaller than the dimension in the vehicle width direction as a whole. ing. The battery pack P is fixed to the lower part of the electric vehicle by fastening a plurality of mounting brackets Br provided on the outer peripheral edge portion to a mounting member (not shown) on the vehicle body side using fasteners such as bolts.

As shown in FIGS. 1 and 2, the battery pack P includes a plurality of battery modules M and a housing 1 for accommodating these modules. As shown in FIG. 3, each battery module M is a modularized component in which a plurality of battery cells 2 are arranged in parallel in the vehicle width direction. The battery modules M are electrically connected to each other in the housing 1 by a wiring member such as a bus bar (not shown).

Each battery cell 2 is, for example, a lithium ion secondary battery, and is configured by sealing a power generation element in which a positive electrode plate and a negative electrode plate are laminated via a separator in an outer case 3 together with an electrolyte. In the battery module M, the battery cells 2 are integrated by electrically connecting the electrode terminals of the adjacent battery cells 2 with each other by a wiring member (not shown). The battery cell 2 is not limited to the lithium ion secondary battery, but may be a nickel hydrogen secondary battery, an organic radical battery, or the like.

The outer case 3 of the battery cell 2 is made of an aluminum can or the like, and a discharge port 4 is formed on the upper surface thereof as shown in FIG. The discharge port 4 is an opening through which the gas is discharged when the gas is generated due to an abnormality inside the battery cell 2. The discharge port 4 is provided with a seal member (not shown) that breaks and discharges gas when the internal pressure of the battery cell 2 becomes equal to or higher than a predetermined pressure. The mechanism for releasing the gas is not limited to the seal member, and may be an explosion-proof valve that opens and releases the gas when the internal pressure of the battery cell 2 becomes equal to or higher than a predetermined pressure. Further, the shape of the discharge port 4 is not limited to the circular shape shown in the figure, but may be an elliptical shape, a polygonal shape, or the like. Further, the discharge port 4 is not limited to the upper surface of the outer case 3, but may be provided on the side surface, the lower surface, or the like of the outer case 3.

As shown in FIGS. 1 and 2, the housing 1 is mainly composed of an upper casing 1 _U and a lower casing 1 _L. The upper casing 1 _U and the lower casing 1 _L are made of, for example, a fiber reinforced resin. The reinforcing fiber of the fiber-reinforced resin is not particularly limited, and carbon fiber, glass fiber, boron fiber, aramid fiber and the like can be used. The matrix resin is not particularly limited, and an epoxy resin, an unsaturated polyester resin, a phenol resin, or the like can be used. The upper casing 1 _U and the lower casing 1 _L can be molded by, for example, a sheet molding compound (SMC) press molding method, a prepreg press molding method, or the like.

The upper casing 1 _U and the lower casing 1 _L are fastened to each other by fasteners such as bolts (not shown), and a storage space H for the battery module M (that is, the battery cell 2) is formed between them. A sealing member (not shown) made of a rubber material or the like is interposed between the peripheral edge of the upper casing 1 _U and the peripheral edge of the lower casing 1 _L to seal the accommodation space H.

As shown in FIG. 2, the lower casing 1 _L is a bottomed box-shaped member having a substantially rectangular shape in a plan view and opening upward. The lower casing 1 _L has a flat bottom wall portion 1 _LB constituting the bottom portion thereof and a peripheral wall portion 1 _LS extending upward from the outer peripheral edge portion of the bottom wall portion 1 _LB.

As shown in FIG. 2, a plurality of battery modules M are arranged in the lower casing 1 _L. In the illustrated example, a total of eight battery modules _M are arranged in the front portion of the lower casing 1L, two rows in the vehicle width direction and four rows in the vehicle front-rear direction. Further, in the rear portion of the lower casing 1L, the battery modules _M are stacked in two upper and lower stages, and the two-stage battery modules M are stacked in two rows in the vehicle width direction and two rows in the vehicle front-rear direction, for a total of eight. It is arranged.

As shown in the illustrated example, a spacer Sp is installed in the lower casing 1 _L so as to divide the inside of the lower casing 1 _L into a plurality of regions, and one battery module M is arranged in each of the divided regions. You may do so. As a result, the spacer Sp is interposed between the adjacent battery modules M, so that the adjacent battery modules M can be held in a state of being separated from each other.

As shown in FIG. 2, the upper casing 1 _U is a plate-shaped member having a substantially rectangular shape in a plan view. In the illustrated example, the upper casing 1 _U bulges upward from the flat wall portion 1 _UF formed in the front portion and the flat wall portion 1 _UF at a position rearward from the flat wall portion 1 _UF . It has a bulging wall portion 1 _UB formed. The bulging wall portion 1 _UB has an upper wall portion 1 _UBT constituting the upper surface thereof and a peripheral wall portion 1 _UBS extending downward from the outer peripheral edge portion of the upper wall portion 1 _UBT . By forming the bulging wall portion 1 _UB , the battery modules M stacked in two stages can be accommodated in the rear portion of the housing 1. As a result, the front portion can be made thinner while suppressing the length of the entire battery pack P in the vehicle front-rear direction. The upper casing 1 _U can seal the accommodation space H in the housing 1 by closing the opening of the lower casing 1 _L from above.

In the present embodiment, the bottom wall portion 1 _LB and the peripheral wall portion 1 _LS of the lower casing 1 _L , and the flat wall portion 1 _UF and the bulging wall portion 1 _UB of the upper casing 1 _U form the accommodation space H in the housing 1. It constitutes a wall portion 5 that defines. The inner surface 5a of the wall portion 5 includes a facing region R facing the discharge port 4 of the battery cell 2. For example, as shown in FIGS. 4 and 5, the facing region R is included in the lower surface of the flat wall portion 1 _UF . The facing region R is a region directly facing the discharge port 4 and the gas discharge direction _XJ (spouting direction), and the inner surface 5a of the wall portion 5 is viewed from the inside of the battery cell 2 in the gas discharge direction _XJ . In this case, it is an area that overlaps with the discharge port 4. Alternatively, the facing region R is a region in which the discharge port 4 is projected in the gas discharge direction _XY with the inner surface 5a of the wall portion 5 as the projection surface. The gas discharge direction _XJ is perpendicular to the opening surface 4a defined by the outer peripheral edge of the discharge port 4.

The facing region R is provided with a deflection surface D. The deflection surface D is a surface that deflects the flow of the gas J (hereinafter, also referred to as a gas jet J) discharged from the discharge port 4 to the outside of the facing region R. In the present embodiment, a ridge 6 protruding toward the discharge port 4 is formed on the inner surface 5a of the wall portion 5. In the examples shown in FIGS. 4 and 5, the discharge port 4 is open upward, and the general surface 5ag of the inner surface 5a facing the discharge port 4 in the vertical direction extends substantially horizontally. The ridge 6 projects downward from the general surface 5ag of the inner surface 5a.

As shown in FIG. 4, the ridge 6 has a mountain-shaped cross section, and two flat inclined surfaces SL adjacent to each other across the ridge line _6r of the ridge 6 form a deflection surface D. .. That is, in the present embodiment, the deflection surface D is inclined with respect to the discharge direction _XJ of the gas discharged from the discharge port 4, and is provided from two inclined surfaces _SL arranged adjacent to each other without a gap. It is configured. In addition, "tilted" means that the posture is neither vertical nor parallel to the gas discharge direction _XJ .

As shown in FIG. 5, the ridge line _6r of the ridge 6 overlaps with the center 4c (see FIG. 4) of the discharge port 4 when the ridge 6 is viewed from the inside of the battery cell 2 in the gas discharge direction XX. It is arranged like this. Therefore, as shown in FIG. 4, the flow of the gas J discharged from the discharge port 4 is roughly divided into two flows by the top portion 6 _T of the ridge 6. The edge of the top 6 _T may be rounded. However, the radius of curvature is preferably set as small as possible within an allowable range determined by the formability of the material constituting the wall portion 5, and is, for example, 0.1 mm to 1.0 mm. By setting the radius of curvature to be smaller, the range of the stagnation region _ST , which will be described later, can be made smaller.

The total width W ₆ of the ridge 6 is larger than the width W ₄ (see FIG. 4) of the discharge port 4 in the direction orthogonal to the extending direction of the ridge 6 and orthogonal to the gas discharge direction _XJ . Therefore, as shown in FIG. 5, the entire facing region R is composed of two inclined surfaces _SL , that is, a deflection surface D. The intersection of the general surface _5ag of the inner surface 5a and the inclined surface SL may be rounded. By providing a roundness at the intersection, the gas flowing from the top _6T along the inclined surface SL toward the intersection can smoothly change the direction of the flow when transferring from the inclined surface _SL to the general surface _5ag . can. As a result, the heat transfer coefficient in the region near the intersection of the general surface 5ag can be reduced.

In the present embodiment, as shown in FIGS. 2 and 3, a plurality of battery cells 2 are arranged in a row so that the discharge ports 4 are arranged in a row along the vehicle width direction, and are housed in the housing 1. Therefore, the inner surface 5a of the wall portion 5 includes a plurality of facing regions R facing each of the plurality of discharging ports 4 of the plurality of battery cells 2, and the plurality of facing regions R are also in the vehicle width direction. They are lined up in a row along. The ridges 6 are continuously formed across a plurality of facing regions R arranged in a row.

In the illustrated example, the number of ridges 6 is the same as the number of rows of the battery module M in the vehicle front-rear direction. Specifically, as shown in FIGS. 1 and 2, four ridges 6 are provided on the flat wall portion 1 _UF and two on the upper wall portion 1 _UBT of the bulging wall portion 1 _UB , for a total of six ridges 6. ing. The ridges 6 provided on the flat wall portion 1 _UF extend continuously in the vehicle width direction over the entire width of the flat wall portion 1 _UF in the vehicle width direction. Further, the ridges 6 provided on the upper wall portion 1 _UBT extend continuously in the vehicle width direction over the entire width of the upper wall portion 1 _UBT in the vehicle width direction.

<Modification example>
In the above embodiment, the surface of the ridge 6 constituting the deflection surface D is composed of only two inclined surfaces SL adjacent to each other with the ridge line _6r in between, but the surface configuration of the ridge 6 is limited to this. do not have. On the surface of the ridge 6 constituting the deflection surface D according to the modified example, in addition to the two inclined surfaces SL adjacent to each other with the ridge line _6r in between, other strips extending in parallel with the extending direction of the ridge 6 are formed. May include an inclined surface of. The width and number of other strip-shaped inclined surfaces are not particularly limited.

In another modification, the ridge line 6r of the ridge 6 may be arranged at a position deviated from the center 4c of the discharge port 4 when viewed from the gas discharge direction _XY . In this case, by adjusting the position of the ridge line 6r, the flow of the gas J discharged from the discharge port 4 can be divided at a desired ratio.

In yet another modification, the surface of the ridge 6 may be composed of one inclined surface SL and a surface perpendicular to the general surface _5ag (a surface parallel to the _outgassing direction XJ). .. In this case, the _deflection surface D may be configured from only the one inclined surface SL.

In yet another modification, the ridges 6 may be discontinuous ridges 6 (hereinafter, discontinuous ridges) individually provided for each of the plurality of facing regions R.

Hereinafter, the effects of the above-described embodiment and its modifications (hereinafter, the first embodiment and the like) will be described.

(1) The deflection surface D deflects the flow of colliding gas. That is, the direction of the flow of the colliding gas is changed while leaving the velocity component (momentum component) of the flow direction (gas discharge direction _XJ ) before the collision. Therefore, the flow near the surface of the gas colliding with the deflection surface D (near the deflection surface D) is near the surface of the gas colliding with the surface perpendicular to the gas discharge direction _XX (hereinafter, the vertical surface) (near the vertical surface). ), It contains more velocity component (momentum component) parallel to the surface. Therefore, the deflection surface D is less likely to form a stagnation region _ST (see FIG. 5) on the surface than the vertical surface. The stagnation region _ST is a region near the stagnation point and the stagnation point, and the velocity component parallel to the surface of the gas flow is substantially zero.

According to the first embodiment and the like, the deflection surface D that deflects the flow of the gas J discharged from the discharge port 4 to the opposite region R facing the discharge port 4 on the inner surface 5a of the housing 1 to the outside of the facing region R. Is provided. Therefore, as compared with the case where the deflection surface D is not provided in the facing region R (that is, when the entire facing region R is composed of only vertical planes, hereinafter, comparative example), the facing region R is in the facing region R. The stagnation region _ST is difficult to form. Even if the stagnation region _ST is formed, the size of the range is smaller than that of the comparative example.

As described above, according to the first embodiment and the like, it is possible to suppress the generation of the stagnation region _ST in the facing region R and reduce the maximum value of the heat transfer coefficient in the facing region R. As a result, the local concentration of the heat load from the gas J (gas jet J) discharged from the discharge port 4 is alleviated, so that damage such as holes in the housing 1 due to the heat from the jet gas is suppressed, which in turn suppresses damage such as holes in the housing 1. The possibility of burning the parts and the like arranged around the battery pack P is also reduced.

(2) Further, according to the first embodiment or the like, unlike the battery pack of Patent Document 1, it is not necessary to provide a smoke exhaust duct which is a member separate from the housing. Therefore, the degree of freedom in designing the battery pack P can be improved without incurring an increase in weight or cost.

(3) Further, according to the first embodiment or the like, the deflection surface D is inclined with respect to the discharge direction _XY of the gas discharged from the discharge port 4, and is arranged adjacent to each other without a gap. It is composed of a plurality of inclined surfaces _SL . Alternatively, the _deflection surface D is composed of one inclined surface SL inclined with respect to the discharge direction _XY of the gas discharged from the discharge port 4. Therefore, since the gas J discharged from the discharge port 4 collides diagonally with the deflection surface D, a force applied from the gas jet J to the deflection surface D in the direction perpendicular to the surface is more than in the case of a vertical collision. Is reduced. This makes it possible to reduce the damage caused to the housing 1 by the gas jet J.

(4) Further, according to the first embodiment or the like, the entire facing region R is composed of the deflection surface D. Therefore, it is possible to suppress the occurrence of the stagnation region _ST in the entire facing region R and more reliably reduce the maximum value of the heat transfer coefficient. This further alleviates the local concentration of heat load.

(5) Further, according to the first embodiment or the like (excluding a modified example in which the _deflection surface D is configured from only one inclined surface SL), the inner surface 5a of the housing 1 projects toward the discharge port 4. Convex 6 is formed. Two inclined surfaces SL adjacent to each other with the ridge line _6r of the ridge 6 interposed therebetween constitute the deflection surface D. Therefore, it is possible to improve the strength and rigidity of the wall portion 5 of the housing 1 while alleviating the concentration of heat load by deflecting the flow of gas colliding with the ridges 6 in two directions on the two inclined surfaces _SL . can.

(6) Further, according to the first embodiment or the like, the wall thickness of the wall portion 5 of the housing 1 is increased by at least the amount in which the ridges 6 are formed, so that the gas jet J is formed on the deflection surface D. Even when a large heat load is input from the above, it is possible to delay the occurrence of holes in the housing 1.

(7) Further, according to the first embodiment or the like, a plurality of battery cells 2 are arranged so that their gas discharge ports 4 are arranged in a row and housed in the housing 1. The inner surface 5a includes a plurality of facing regions R facing each of the plurality of discharging ports 4 of the plurality of battery cells 2. Then, according to the first embodiment (excluding the discontinuous ridges), the ridges 6 are continuously formed across the plurality of facing regions R. According to this structure, the strength and rigidity of the wall portion 5 of the housing 1 can be efficiently improved while alleviating the concentration of heat load by the small number of ridges 6.

(8) In the first embodiment or the like, the inclination angles of the two inclined surfaces SL of the ridges 6 with respect to the gas discharge direction _XJ are not particularly limited, but the gas discharge directions _XJ and the _ridges 6 are not particularly limited. The angle θ (see FIG. 4) formed by the normal of each _inclined surface SL is preferably 60 ° or more and 75 ° or less. In this case, the force acting from the gas jet J in the direction perpendicular to the plane D with respect to the deflection surface D is more reliably reduced, so that the life of the housing 1 can be extended.

Next, the second and third embodiments, and the battery pack P according to the other embodiments will be described with reference to FIGS. 6 to 9. In the description of each embodiment, only the configuration different from the preceding embodiment and the modified example (hereinafter, the preceding embodiment and the like) will be described, and the element having the same function as the element already described in the preceding embodiment and the like will be described. Have the same reference numerals, and the description thereof will be omitted.

<Second Embodiment>
As shown in FIGS. 6 and 7, in the battery pack P according to the second embodiment, a cone-shaped convex portion 7 protruding toward the discharge port 4 is formed on the inner surface 5a of the housing 1. The side surface 7 _L of the conical convex portion 7 constitutes the deflection surface D.

In the illustrated example, the shape of the cone-shaped convex portion 7 is conical. As shown in FIG. 7, the apex _7v is arranged so as to overlap the center 4c (see FIG. 6) of the discharge port 4 when the cone-shaped convex portion 7 is viewed from the gas discharge direction XX. .. Therefore, the flow of the gas J discharged from the discharge port 4 is evenly and radially divided by the top portion 7 _T of the cone-shaped convex portion 7. The tip of the top 7 _T may be rounded. However, the radius of curvature is preferably set as small as possible within an allowable range determined by the formability of the material constituting the wall portion 5, and is, for example, 0.1 mm to 1.0 mm.

The minimum width W ₇ of the cone-shaped convex portion 7 in the direction orthogonal to the gas discharge direction _XJ is larger than the maximum width W ₄ (see FIG. 6) of the discharge port 4 in the direction. Therefore, as shown in FIG. 7, the entire facing region R is composed of the side surface 7 _L of the cone-shaped convex portion 7, that is, the deflection surface D. The intersection of the side surface 7L of the cone-shaped convex portion 7 and the general surface _5ag of the inner surface 5a may be rounded. By providing a roundness at the intersection, the gas flowing from the top _7T along the side surface 7L toward the intersection can smoothly change the direction of the flow when transferring from the side surface _7L to the general surface _5ag . As a result, the heat transfer coefficient in the region near the intersection of the general surface 5ag can be reduced.

In the present embodiment, as in the first embodiment, the inner surface 5a of the wall portion 5 includes a plurality of facing regions R facing each of the plurality of discharging ports 4 of the plurality of battery cells 2. The plurality of facing regions R are arranged in a row along the vehicle width direction, and the cone-shaped convex portions 7 are formed in each of the plurality of facing regions R arranged in a row.

<Modification example>
The shape of the cone-shaped convex portion 7 is not limited to the conical shape, but may be an elliptical cone shape, a prismatic shape, or a combination thereof. Here, when the shape of the cone-shaped convex portion 7 is a conical shape or an elliptical pyramid shape, the side surface 7 _L of the cone-shaped convex portion 7 is one curve inclined with respect to the gas discharge direction _XJ . A deflection surface _D composed of the inclined surface SL is configured. On the other hand, when the shape of the cone-shaped convex portion 7 is a pyramidal shape, the side surface 7 _L of the cone-shaped convex portion 7 is inclined with respect to the gas discharge direction _XJ , and is adjacent to each other without a gap. A deflection surface _D composed of a plurality of flat inclined surfaces SL arranged in the above direction is configured.

(9) Since the second embodiment and its modifications (hereinafter, the second embodiment and the like) have at least the configurations described in the above (1) to (4), the above (1) to (4) can be used. The described effects can be obtained.

(10) Further, according to the second embodiment or the like, a conical convex portion 7 projecting toward the discharge port 4 is formed on the inner surface 5a of the housing 1, and the conical convex portion 7 is formed. The side surface 7 _L constitutes the deflection surface D. Therefore, since the wall thickness of the wall portion 5 of the housing 1 is increased by at least the amount of the cone-shaped convex portion 7 formed, when a large heat load is input to the deflection surface D from the gas jet J. Even if there is, it is possible to delay the occurrence of holes in the housing 1.

(11) Further, according to the second embodiment or the like, since the side surface 7 _L of the conical convex portion 7 constitutes the deflection surface D, the flow of the gas that collides with the deflection surface D and is deflected is For example, it will be dispersed in more directions than when it collides with two inclined surfaces of a mountain-shaped cross-section convex and is deflected in two directions. Therefore, the concentration of heat load in the facing region R is further relaxed.

<Third Embodiment>
In the battery pack P according to the third embodiment, as shown in FIGS. 8 and 9, the wall portion 5 of the housing 1 has a general portion 5A and a thick portion 5B thicker than the general portion 5A. I have. The deflection surface D is composed of a portion of the thick portion 5B located in the facing region R.

In the illustrated example, the deflection surface _D is composed of one inclined surface SL inclined with respect to the discharge direction _XY of the gas discharged from the discharge port 4. Further, the thick portion 5B constitutes a rib 8 protruding inward of the accommodation space H from the general surface 5ag of the inner surface 5a. The ribs 8 may be continuously formed along the parallel direction (in the present embodiment, the vehicle width direction) of the gas discharge ports 4 arranged side by side in the housing 1. The rib 8 may be arranged so as to straddle a plurality of facing regions R. As a result, the strength and rigidity of the wall portion 5 of the housing 1 can be efficiently improved.

(12) Since the third embodiment has at least the configurations described in the above (1) to (4), the effects described in the above (1) to (4) can be obtained.

(13) Further, according to the third embodiment, the wall portion 5 of the housing 1 includes a general portion 5A and a thick portion 5B thicker than the general portion 5A, and the deflection surface D has a deflection surface D. It is composed of a portion of the thick portion 5B located in the facing region R. That is, the portion 5B ₁ constituting the deflection surface D of the thick portion 5B is heat transferably connected to the portion 5B ₂ of the thick portion 5B located outside the facing region R. Therefore, even when a heat load is input to the deflection surface D from the gas jet J, the portion 5B ₁ located inside the facing region R becomes the thick portion 5B (part 5B ₂ ) located outside the facing region R. The heat can be dissipated, and the generation of holes in the housing 1 can be delayed by that amount.

(14) Further, according to the third embodiment, the deflection surface _D is composed of one flat inclined surface SL inclined with respect to the discharge direction _XY of the gas discharged from the discharge port 4. , The flow of gas colliding with the deflection surface D can be deflected in a specific direction. That is, the deflection direction of the gas flow can be controlled.

(15) In the third embodiment, the inclination angle of the inclined surface _SL with respect to the gas discharge direction _XJ is not particularly limited, but is formed by the gas discharge direction _XJ and the normal line of the inclined surface _SL . The angle θ (see FIG. 8) is preferably 60 ° or more and 75 ° or less. In this case, the force acting from the gas jet J in the direction perpendicular to the plane D with respect to the deflection surface D is more reliably reduced, so that the life of the housing 1 can be extended.

<Other embodiments>
In the battery pack P according to the other embodiment, a part or all of the flat inclined surface SL constituting the _deflection surface D as in the preceding embodiment may be replaced with the inclined surface made of a curved surface. In this case, the surface shape of the deflection surface D can be streamlined, the turbulence of the deflected gas jet J can be suppressed, and the increase in heat transfer coefficient can be suppressed.

Further, in the battery pack P according to another other embodiment, the deflection surface D may be formed only in a part of the facing region R. That is, the facing region R may include a vertical plane as a part. Even in this case, the generation of the stagnation region _ST in the facing region R can be suppressed as compared with the above comparative example.

In the battery pack P according to still another embodiment, the shape of the housing 1, the arrangement / number of the battery modules M in the housing 1, the number of the battery cells 2 per the battery module M, and the like are determined in the preceding embodiment and the like. It may be different from that of. The number of battery cells 2 housed in the housing 1 is not particularly limited, and may be 1 or more.

Yet another embodiment is a combination of two or more embodiments or modifications selected from the preceding embodiments and the like. For example, the deflection surface D of the third embodiment may be composed of the deflection surface D according to the first embodiment or the like, or the deflection surface D according to the second embodiment or the like. In the embodiment related to these combinations, each effect of the embodiment or the modification corresponding to each of the combined elements can be obtained.

The above embodiments and modifications are merely examples described for facilitating the understanding of the invention. The technical scope of the invention is not limited to the specific technical matters disclosed in the above embodiments and the like, but also includes various modifications, changes, alternative techniques and the like that can be easily derived from the specific technical matters.

1 Housing 2 Battery cell 4 Discharge port R Facing area 5 Wall part 5a Inner surface D Deflection surface S _L Inclined surface 5A General part 5B Thick part 6 Convex 6r Ridge line 7 Conical convex part 7 _L Side surface X _J Discharge direction H accommodation space

Claims (8)

With at least one battery cell having a gas outlet,
A housing accommodating the at least one battery cell and
Equipped with
A battery pack structure in which a deflection surface that deflects the flow of gas discharged from the discharge port to the outside of the facing region is provided in a region facing the discharge port on the inner surface of the housing. One inclined surface in which the deflection surface is inclined with respect to the discharge direction of the gas discharged from the discharge port, or a plurality of inclined surfaces which are inclined with respect to the discharge direction and are arranged adjacent to each other without a gap. The battery pack structure according to claim 1, which is composed of an inclined surface of the above. The battery pack structure according to claim 1 or 2, wherein the entire facing region is composed of the deflection surface. A ridge protruding toward the discharge port is formed on the inner surface of the housing.
The battery pack structure according to any one of claims 1 to 3, wherein two inclined surfaces adjacent to each other with the ridge line of the convex strip forming the deflection surface. A plurality of the battery cells are arranged in a row so that their gas discharge ports are arranged and housed in the housing.
The inner surface of the housing comprises a plurality of facing regions, each facing a plurality of outlets of the plurality of battery cells.
The battery pack structure according to claim 4, wherein the ridges are continuously formed over the plurality of facing regions. The battery pack structure according to claim 4 or 5, wherein the angle between the discharge direction of the gas discharged from the discharge port and the normal of each inclined surface of the ridge is 60 ° or more and 75 ° or less. A cone-shaped convex portion protruding toward the discharge port is formed on the inner surface of the housing.
The battery pack structure according to any one of claims 1 to 3, wherein the side surface of the cone-shaped convex portion constitutes the deflection surface. The housing comprises a wall that defines a storage space in which the at least one battery cell is housed.
The wall portion includes a general portion and a thick portion thicker than the general portion.
The battery pack structure according to any one of claims 1 to 3, wherein the deflection surface is composed of a portion of the thick portion located in the facing region.

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