JP2017069068A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact size power storage device capable of securing coolability of an electric cell and including densely arranged electric cells.SOLUTION: A power storage device 10 comprises a plurality of electric cells 14 arranged in a first direction, and a cap 22 covering one side in a second direction orthogonal to the first direction in each of the plurality of electric cells 14. The cap 22 includes a plurality of passages communicating with each gap between adjacent electric cells 14.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a power storage device including a plurality of unit cells.

  Conventionally, a power storage device including a plurality of unit cells arranged in a line is known. For example, in the case of the power storage device described in Patent Document 1, for each of the plurality of unit cells, the end opposite to the end provided with the external terminal is covered with a cap. The plurality of single cells are attached to a frame-shaped base through a cap in a state where they are arranged. The air that has passed through the frame-shaped base flows into the gap between the adjacent cells via the gap between the caps. Thereby, each single cell is cooled.

JP 2012-204298 A

  In recent years, there has been a demand for a power storage device that is made compact by arranging a plurality of single cells closely. However, when a cap is attached to each unit cell as in the power storage device described in Patent Document 1, if a plurality of unit cells are arranged closely, the gap between the caps becomes narrower. As a result, the flow rate of the airflow passing through the gap between the caps is reduced, and the cooling performance of the unit cell is lowered.

  Therefore, the present invention provides a power storage device provided with a plurality of single cells with caps arranged in a row, and a plurality of single cells are closely arranged in a compact size while suppressing a decrease in cooling performance of each single cell. The challenge is to make it.

In order to solve the above technical problem, according to the first aspect of the present invention,
A plurality of cells arranged in a first direction;
A cap that covers one side of the second direction orthogonal to the first direction in each of the plurality of unit cells,
A power storage device is provided in which a cap includes a plurality of flow paths communicating with gaps between adjacent unit cells.

  According to the first aspect of the present invention, the power storage device including the plurality of single cells with the caps arranged therein is arranged while the deterioration of the cooling performance of each single cell is suppressed. Batteries can be arranged closely to make a compact size.

According to a second aspect of the invention,
The caps are a plurality of caps each covering one side in the second direction of the unit cell,
A power storage device according to a first aspect is provided in which each of a plurality of caps includes a recess that forms a flow path.

  According to such a 2nd aspect of this invention, the fall of the rigidity of a cap can be suppressed compared with the case where a some flow path is comprised by the through-hole which penetrates each of a some cap. In order to suppress the decrease in rigidity, it is conceivable to make the cap part where the through hole is formed thick, but this makes the cap larger, and as a result, it is difficult to arrange the cells closely. become.

According to a third aspect of the invention,
Each of the plurality of caps is formed on one side in the first direction and communicates with a gap between adjacent unit cells, and is formed on the other side in the first direction. A power storage device according to a second aspect is provided that includes a second recess that forms a flow path by communicating with and partially opposing a first recess of another adjacent cap.

  According to such a third aspect of the present invention, when the concave portion extending from the gap between the adjacent unit cells to the bottom of the cap is formed only on one side or only the other side of the cap in the first direction. As compared with the above, it is possible to suppress a decrease in the rigidity of the cap. In order to suppress the decrease in rigidity, it is conceivable to make the cap portion with the concave portion thick, but this increases the size of the cap, which makes it difficult to arrange the cells closely. Become.

According to a fourth aspect of the invention,
A power storage device according to the second or third aspect is provided in which a plurality of caps have the same shape.

  According to such a 4th aspect, manufacture of an electrical storage apparatus becomes easy compared with the case where a some cap differs.

According to a fifth aspect of the present invention,
A power storage device according to any one of the first to fourth aspects is provided, wherein the cap is configured such that a part of the unit cell covered with the cap is exposed in the flow path.

  According to such a 5th aspect of this invention, the part of the cell covered with the cap is cooled by the airflow which passes along a flow path.

According to a sixth aspect of the present invention,
A base portion for holding a plurality of cells arranged in the first direction via a cap;
A power storage device according to any one of the first to fifth aspects is provided, wherein the base portion includes a plurality of openings facing each of the plurality of flow paths.

  According to such a 6th aspect, airflow is supplied to a pinpoint between caps via opening.

According to a seventh aspect of the present invention,
A plurality of cells are arranged in a first direction in a plurality of rows,
A plurality of openings opposed to a plurality of flow paths communicating with the gaps of the plurality of single cells in one row adjacent to each other, and a plurality of flow paths communicating with each of the gaps of the plurality of single cells in the other row. A power storage device according to a sixth aspect is provided in which a plurality of openings facing each other are formed in the base portion so that the positions in the first direction are different.

  According to such a 7th aspect, several opening which opposes with respect to the several flow path connected to each of the clearance gap between the unit cells of one adjacent row | line | column, and the clearance gap between the several unit cell of the other row | line | column The deformation and breakage of the base portion are suppressed as compared to the case where the base portion is provided with the plurality of openings facing the plurality of flow paths communicating with each other so that the first direction positions are the same.

According to an eighth aspect of the present invention,
A base portion for holding a plurality of cells arranged in the first direction via a plurality of caps;
Each of the plurality of caps includes an engaging portion for engaging with the base portion,
The base portion includes a plurality of engaging portions that engage with the engaging portions of the caps,
The engaging portion of the cap and the engaging portion of the base portion are configured such that the first recessed portion of one adjacent cap and the second recessed portion of the other cap partially constitute a flow path. A power storage device of a third aspect configured to engage with each other is provided.

  According to such an eighth aspect, the first concave portion of one of the adjacent caps and the second concave portion of the other cap are surely partially opposed to each other, so that the gap between the adjacent caps is assured. An air flow path is reliably formed.

  According to the present invention, a power storage device provided with a plurality of unit cells with caps arranged in a row is arranged in a compact size by closely arranging a plurality of unit cells while suppressing a decrease in cooling performance of each unit cell. Can be.

The perspective view of the electrical storage apparatus which concerns on one embodiment of this invention The perspective view which shows the back side of an electrical storage apparatus Disassembled perspective view of power storage device Exploded view of battery module Plan view showing electrical connection of multiple cells The perspective view of the cell of the state in which the 1st and 2nd cap was attached FIG. 6A is a further perspective view of the unit cell with the first and second caps attached, as seen from a different direction from FIG. 6A. Perspective view of second cap The perspective view of the 2nd cap seen from the direction different from Drawing 6A. Perspective view of base portion of power storage device The perspective view of the base part of an electrical storage apparatus seen from the direction different from FIG. 7A Cross section of power storage device Layout diagram of multiple openings in the base Cross-sectional view of adjacent second caps Sectional drawing of the 2nd cap which adjoins in the electrical storage apparatus which concerns on another embodiment Sectional drawing of the 2nd cap in the electrical storage apparatus which concerns on another form Furthermore, sectional drawing of the 2nd cap and heat insulation board in the electrical storage apparatus which concerns on a different form

  Hereinafter, a power storage device according to an embodiment of the present invention will be described with reference to the drawings.

  1 and 2 are perspective views of a power storage device according to an embodiment of the present invention. FIG. 3 is an exploded view of the power storage device. In order to facilitate understanding of the invention, an XYZ coordinate system including an X axis, a Y axis, and a Z axis that are orthogonal to each other is defined. The X-axis direction indicates the width direction in the power storage device, the Y-axis direction indicates the depth direction, and the Z-axis direction indicates the height direction. Further, in this specification, “upper side” and “lower side” indicate “upper side” and “lower side” in the drawings, and an “upper side” element always exists above the “lower side” element. The power storage device according to the present invention is not limited to being used in the state.

  As shown in FIGS. 1-3, the electrical storage apparatus 10 is a substantially rectangular parallelepiped shape, and has the battery module 12 in the inside. For example, in order to store regenerative energy as electricity, a plurality of power storage devices 10 are mounted in the lower part of the railway vehicle.

  As shown in FIG. 3, the battery module 12 is composed of a plurality of single cells 14. In the case of the present embodiment, the battery module 12 is configured by twelve unit cells 14 arranged in two rows in the depth direction (Y-axis direction).

  FIG. 4 is an exploded view of the battery module 12. As shown in FIG. 4, each of the unit cells 14 has a substantially rectangular parallelepiped shape, and the positive electrode terminal 14a and the negative electrode terminal 14b as external terminals are arranged on one end surface (upper end surface) in the height direction (Z-axis direction). 14c. Further, in the width direction (X-axis direction), the depth direction (Y-axis direction), and the height direction (Z-axis direction), the size in the width direction is the largest and the size in the depth direction is the smallest.

  As shown in FIGS. 4 and 5, in the battery module 12, the plurality of single cells 14 are electrically connected in series to form a series circuit. Specifically, each of the positive terminal 14a and the negative terminal 14b of the plurality of unit cells 14 is connected to the positive terminal 14a and the negative terminal 14b of another unit cell 14 adjacent to each other through a metal plate 16 made of a copper material or the like. Electrically connected. In the series circuit of the battery module 12, a negative electrode terminal 14b of one unit cell 14 (14A) located at each end and a positive electrode terminal 14a of the other unit cell 14 (14B) are connected to an external device (for example, other unit). A takeout terminal 18 for electrical connection with the power storage device 10) is attached.

  As shown in FIGS. 3 to 7, the positive terminal 14 a and the negative terminal 14 b of each unit cell 14 are covered and protected by the first cap 20. Specifically, the first cap 20 is made of a resin material, and two each of the unit cells 14 are provided. One first cap 20 is attached to the corner so as to cover the corner of the unit cell 14 on the positive electrode terminal 14a side. The other first cap 20 is attached to the corner so as to cover the corner of the unit cell 14 on the negative electrode terminal 14b side. Note that the two first caps 20 attached to each unit cell 14 are separate, but may be integrated.

  As shown in FIG. 3 to FIG. 7, each unit cell 14 has one end (upper end) in the height direction (Z-axis direction) where the positive electrode terminal 14 a and the negative electrode terminal 14 b are provided. A second cap 22 is attached to the other end (lower end) of the opposite unit cell 14.

  Similar to the first cap 20, the second cap 22 is made of a resin material. However, unlike the first cap 20, the second cap 22 covers the lower end of the unit cell 14 over the entire width direction (X-axis direction) and depth direction (Y-axis direction). Further details of the second cap 22 will be described later.

  As illustrated in FIGS. 1 to 3, the power storage device 10 includes a base unit 24 that holds a plurality of unit cells 14 (battery modules 12) and a cover unit 26 that covers the plurality of unit cells 14 held by the base unit 24. And have. In the case of the present embodiment, the plurality of single cells 14 (battery modules 12) are sandwiched between the base portion 24 and the cover portion 26. The base portion 24 and the cover portion 26 are supported by the side portions 28 and 30 by fixing both ends in the width direction (X-axis direction) to the side portions 28 and 30.

  The cover portion 26 is a member formed by, for example, sheet metal pressing a thin metal plate, and holds the first cap 20 in a state of being attached to each unit cell 14. Specifically, each of the first caps 20 is provided with a columnar engagement portion 20a that protrudes in the height direction (Z-axis direction). On the other hand, the cover portion 26 is formed with a plurality of engagement holes 26a into which the engagement portions 20a of the plurality of first caps 20 can be inserted.

  The base portion 24 is a member formed, for example, by sheet metal pressing a thin metal plate, and holds the second cap 22 in a state of being attached to each unit cell 14. Specifically, as shown in FIGS. 2 and 6 to 9, particularly as shown in FIG. 9, the lower end (positive electrode terminal 14 a and negative electrode terminal) of the unit cell 14 in the height direction (Z-axis direction). Two cylindrical engaging portions 22b protruding in the height direction are provided on the bottom portion 22a of the second cap 22 facing the upper end portion on the opposite side to the upper end portion on which 14b is provided. . On the other hand, as shown in FIGS. 2 and 10 to 11, in the base portion 24, the engaging portions 22 b of the plurality of second caps 22 can be inserted into the battery holding portion 24 a that holds the plurality of unit cells 14. A plurality of engaging holes 24b.

  Each engaging portion 20a of the first cap 20 is inserted into the engaging hole 26a of the cover portion 26, and each engaging portion 22b of the second cap 22 is inserted into the engaging hole 24b of the base portion 24. . As a result, the unit cell 14 with the first cap 20 and the second cap 22 attached thereto is sandwiched between the cover portion 26 and the base portion 24.

  Note that the base portion 24 that holds the plurality of single cells 14 via the second cap 22 functions as a base of the power storage device 10 and is greatly involved in the rigidity of the power storage device 10 as a whole. Therefore, the base part 24 is configured to suppress the deformation.

  Specifically, as shown in FIGS. 3, 10, and 11, the base portion 24 is formed from the periphery of the battery holding portion 24 a that holds the plurality of single cells 14, on the side opposite to the single cells (no single cells 14 exist). Frame-like second ribs 24c projecting to the side) and first ribs 24d projecting from the portion of the battery holding portion 24a surrounded by the second ribs 24c to the counter-cell side. For example, the second rib 24c is formed by bending and raising the periphery of the thin metal plate. For example, the first rib 24d is formed by cutting and raising.

  The frame-shaped second rib 24c and the first rib 24d provided on the inside thereof suppress the deformation of the base portion 24 due to the weight of the plurality of unit cells 14 on the battery holding portion 24a, and The portion 24 can be reduced in weight (compared to the case where the ribs 24c and 24d are not provided).

  When the base portion 24 is configured without providing the first rib 24d and the second rib 24c, the base portion 24 needs to be made of a metal plate having a thickness that does not deform due to the weight of the plurality of unit cells 14. . However, in that case, the weight of the base portion 24 increases, and as a result, the weight of the power storage device 10 increases. The power storage device 10 with increased weight is not suitable for mounting on a moving body such as a vehicle.

  On the other hand, by providing the first rib 24d and the second rib 24c, the base portion 24 is made of a light metal thin plate and has sufficient rigidity (flexure rigidity and bending rigidity) with respect to the weight of the plurality of unit cells 14. Can be secured. Moreover, as shown in FIG. 2, the rigidity of the base part 24 in which the several through-hole (The engagement hole 24b and the ventilation port (opening) 24e mentioned later) is formed can be improved. Accordingly, the power storage device 10 having high rigidity and light weight that is suitable for mounting on a moving body such as a vehicle can be realized.

  As shown in FIG. 11, the first rib 24d is preferably provided at the center of the portion of the base portion 24 surrounded by the second rib 24c that is easily bent. When the base portion 24 is long in one direction, the first rib 24 d preferably extends in the longitudinal direction of the base portion 24. In the case of this embodiment, the first rib 24d extends in the width direction (X-axis direction).

  Further, when the power storage device 10 is placed and used on a plane, the frame-shaped second rib 24c and the first rib 24d provided on the inner side thereof have a protruding height from the battery holding portion 24a. Preferably they are equal. Thereby, the weight of the plurality of single cells 14 on the battery holding portion 24a of the base portion 24 can be supported not only by the second rib 24c but also by the first rib 24d. As a result, the deformation of the base portion 24 can be further suppressed.

  Furthermore, the first rib 24d and the second rib 24c not only suppress the deformation of the base portion 234 but also serve as heat radiating fins. That is, it plays a role of releasing heat transferred from the unit cell 14 to the base portion 24 to the outside. Thereby, the base part 24 functions as a heat sink excellent in heat dissipation, and can cool the unit cell 14.

  In addition, since the first rib 24d protrudes from the battery holding portion 24a of the base portion 24 to the anti-unit cell side (side where the unit cell 14 does not exist), the plurality of unit cells 14 on the battery holding portion 24a The degree of freedom of arrangement is high (compared to the case where the first rib 24d protrudes toward the unit cell). For this reason, the number of unit cells 14 that can be arranged on the battery holding portion 24a or the size thereof increases. Therefore, the energy density of power storage device 10 increases.

  Furthermore, the second cap 22 is configured so that the unit cell 14 does not fall when the unit cell 14 with the first and second caps 20 and 22 attached thereto is attached to the base portion 24.

  Specifically, the engagement portion 22b of the second cap 22 is sufficient so that the engagement portion 22b of the second cap 22 does not come out of the engagement hole 24b of the base portion 24 even if the unit cell 14 is inclined. Height (size in the height direction (Z-axis direction))). As a result, even when the unit cell 14 with the second cap 22 attached is mounted on the base part 24, even if the unit cell 14 contacts the unit cell 14 that has already been attached to the base unit 24, The already installed unit cell 14 will not fall down. As a result, the assemblability of the power storage device 10 is improved.

  Furthermore, as shown in FIG. 1, a monitoring module 32 that monitors the state of the power storage device 10 is attached to the side portion 30. The monitoring module 32 is configured to monitor the temperature and voltage of the unit cell 14 via, for example, a sensor (not shown) attached to one of the unit cells 14 of the battery module 12.

  In addition, as shown in FIG. 3, the side portions 28 and 30 support the base portion 24 and the cover portion 26, and support a plurality of heat insulating plates (spacers) 34.

  Specifically, the heat insulating plate 34 is supported by the side portions 28 and 30 at both ends in the width direction (X-axis direction), and is disposed in a gap between the unit cells 14 adjacent to each other in the depth direction (Y-axis direction). . By this heat insulating plate 34, the temperature rise of the unit cell 14 due to heat radiation from the adjacent unit cell 14 is suppressed.

  In relation to the temperature of the unit cell 14, as shown in FIG. 1 and FIG. 3, a plurality of slot-shaped ventilation openings (openings) that are long in the width direction (X-axis direction) through which an air flow for cooling the unit cell 14 passes. 26b is formed in the cover portion 26.

  Similarly, as shown in FIGS. 2 and 3, the base portion 24 is also formed with a plurality of slot-shaped vent holes 24e that are long in the width direction (X-axis direction).

  FIG. 12 is a schematic cross-sectional view of the power storage device 10. As shown in FIG. 12, the ventilation opening 26 b of the cover portion 26 is formed in the cover portion 26 so as to face a gap between the unit cells 14 adjacent to each other in the depth direction (Y-axis direction).

  On the other hand, the ventilation opening 24e of the base portion 24 is formed at the position of the base portion 24 facing the gap between the second caps 22 attached to the unit cells 14 adjacent to each other in the depth direction (Y-axis direction). Yes. Therefore, the ventilation opening 26b of the cover part 26 and the ventilation opening 24e of the base part 24 oppose a height direction (Z-axis direction).

  Due to the ventilation port 26b of the cover part 26 and the ventilation port 24e of the base part 24, the gap between the single cells 14 adjacent to each other in the depth direction (Y-axis direction) is extended from the ventilation hole 24e of the base part 24 to the cover part 26. It becomes possible to generate the airflow F (broken line) toward the ventilation opening 26b.

  For example, when the power storage device 10 is attached to the lower part of the railway vehicle, traveling wind flows in through the ventilation openings 24e of the base portion 24, passes through the gaps between the single cells 14, and passes through the ventilation openings 26b of the cover portion 26. Spills through. In this case, the power storage device 10 is provided with guide means (not shown) such as a duct that guides the traveling wind to the vent 24 e of the base portion 24.

  Each of the unit cells 14 in the power storage device 10 can be cooled by the airflow F by the vent hole 26 b of the cover part 26 and the vent hole 24 e of the base part 24. In addition, by forming a vent 24e in the base portion 24 at a position that faces a plurality of gaps between the plurality of single cells 14, that is, a plurality of gaps between the plurality of second caps 22, A reduction in the rigidity of the base portion 24 can be suppressed. In other words, the opening formed in the base portion 24 is minimized, thereby suppressing a decrease in the rigidity of the base portion 24 (sufficient rigidity is ensured).

  In addition, a part of the vent 24e of the base portion 24 is configured by a through-hole generated when the first rib 24d is formed by cutting and raising. Thereby, in the base part 24, the ventilation hole 24e and the 1st rib 24d can be created simultaneously. Further, the first rib 24d functions as a guide for guiding the airflow F into the corresponding vent 24e. As a result, a large amount of airflow F flows into the gaps between the single cells 14 facing the ventilation opening 24e, and the single cells 14 are efficiently cooled.

  Further, as shown in FIG. 13 when the power storage device 10 (that is, the base portion 24) is viewed from the back side, the plurality of ventilation openings 24e formed in the base portion 24 are arranged in the longitudinal direction (that is, the width direction (X axis) of the base portion 24. The base portion 24 is formed so as not to face each other in the direction)). In other words, the plurality of ventilation openings 24e have different positions in the depth direction (Y-axis direction).

  Specifically, as shown in FIG. 3, the plurality of single cells 14 are arranged in two rows in the depth direction (Y-axis direction). Therefore, the ventilation openings 24e of the base portion 24 for generating the airflow F in the gaps between the single cells 14 are also arranged in two rows in the depth direction.

  At this time, when the vent holes 24e in one row (the left column in the figure) and the vent holes 24e in the other row (the right column in the figure) are arranged in the width direction (X-axis direction), the base portion 24 therebetween. There is a possibility that stress concentrates on this portion, and the base portion 24 is deformed or broken at that portion.

  In order to alleviate such stress concentration, as shown in FIG. 13, a plurality of ventilation holes 24e in one row and the ventilation openings 24e in the other row are not opposed to each other in the width direction (X-axis direction). The ventilation opening 24 e is formed in the base portion 24. Specifically, as shown in FIG. 13, the center of the vent 24e in the depth direction (Y-axis direction) is shifted with respect to the gap between the adjacent second caps 22, and the ventilation of one row is performed. The mouth 24e and the vents 24e in the other row are displaced in the opposite directions.

  Further, as shown in FIG. 2, the vent 24 e of the base portion 24 is formed in the base portion 24 so that the longitudinal direction (X-axis direction) is parallel to the longitudinal direction (X-axis direction) of the unit cell 14. ing. That is, the longitudinal direction of the gap between the unit cells 14 adjacent to each other in the depth direction (Y-axis direction) is parallel to the longitudinal direction of the vent hole 24e. As a result, most of the airflow F that has passed through the vent 24e flows into the gap between the unit cells 14 that are adjacent in the depth direction, and the unit cell 14 is efficiently cooled (the longitudinal direction of the vent 24e is the depth). As compared to the case of a twisted positional relationship with respect to the longitudinal direction of the gap between the unit cells 14 facing each other in the direction).

  In order to realize the compact power storage device 10, it is preferable to arrange the plurality of unit cells 14 as densely as possible. However, when the plurality of single cells 14 are arranged closely, the gap between the second caps 22 attached to them becomes narrow. As a result, the flow rate of the airflow F that passes through the gaps between the unit cells 14 decreases, and the cooling performance of the unit cells 14 decreases.

  As a countermeasure, as shown in FIG. 8, each of the second caps 22 is formed with a first recess 22c and a second recess 22d.

  The “recessed portion” of the second cap 22 referred to in this specification refers to a portion that is recessed from the outer surface of the second cap 22, and includes a through portion that extends from the outer surface to the inner surface.

  As shown in FIG. 8, the first and second recesses 22c and 22d are formed in the side wall portions 22e and 22f facing each other in the depth direction (Y-axis direction). The first recess 22c has a cut shape, and the second recess 22d has a through hole shape.

  Specifically, as shown in FIG. 14, which is a cross-sectional view of the second cap 22 adjacent in the depth direction (Y-axis direction), the first recess 22 c extends from the opening end 22 g of the second cap 22. The side wall portion 22e is cut from the opening end 22g so as to extend to the substantially central portion in the height direction (Z-axis direction). That is, the first recess 22 c communicates with the gap between the adjacent unit cells 14.

  On the other hand, the second recess 22d is formed so as to penetrate the side wall portion 22f so as to extend from the bottom portion 22a of the second cap 22 to a substantially central portion in the height direction (Z-axis direction). In other words, as shown in FIG. 8, the second recess 22d is cut from the opening end 22g to the bottom 22a of the second cap 22, and the two corners sandwiched between the notch and the opening end 22g are formed in the width direction. It is a through-hole shape formed by connecting with a bridging portion 22j extending in the (X-axis direction). That is, the second recess 22 d communicates with the bottom 22 a of the cap 22.

  Accordingly, a part of the first recess 22c and a part of the second recess 22d are opposed to the depth direction (Y-axis direction) at a substantially central position in the height direction (Z-axis direction) of the second cap 22. doing.

  As shown in FIG. 12 and FIG. 14, when a plurality of second caps 22 having such first and second recesses 22 c and 22 d are arranged in the depth direction (Y-axis direction), adjacent second caps 22 are arranged. One first recess 22c of the cap 22 and the other second recess 22d partially face each other. In the case of the present embodiment, specifically, the first recess 22c of one second cap 22 and the other second cap 22 are approximately at the center position in the height direction (Z-axis direction) of the second cap 22. The second concave portion 22d of the cap 22 faces.

  As shown in FIG. 14, the first recess 22 c of one second cap 22 and the second recess 22 d of the other second cap 22 face each other, so that the space between these second caps 22 is increased. A flow path of an air flow F (broken line) extending in the height direction (Z-axis direction) is formed. That is, the flow path of the airflow F that communicates with the gap between the adjacent unit cells 14 and communicates with the bottom 22 a of the second cap 22 is formed. The air flow F passes through the second recess 22 d of the other second cap 22 and then passes through the first recess 22 c of the one second cap 22.

  In this way, the flow rate of the air flow F flowing through the gap between the single cells 14 by forming the flow path of the air flow F between the second caps 22 with the first recess 22c and the second recess 22d facing each other. Increases (compared to the case where these recesses are not present). Therefore, even if the cells 14 are arranged closely and the gap between the second caps 22 is narrowed, a sufficient amount of the airflow F creates a gap between the cells 14 by the first recess 22c and the second recess 22d. Can flow. As a result, the power storage device 10 having a compact size can be realized by closely arranging the plurality of unit cells 14 while suppressing a decrease in cooling performance of each unit cell 14.

  In addition, a concave portion communicating with the gap of the unit cell 14 and the bottom portion 22a of the second cap 22 may be formed as a flow path through which the airflow F flows only in one of the side wall portions 22e and 22f of the second cap 22. Conceivable. However, there is a possibility that the rigidity of the side wall portion of the second cap 22 in which such a recess is formed is lowered. As a result, when the power storage device 10 is mounted on a vehicle, the second cap 22 may be damaged by the vibration of the traveling vehicle. In order to suppress the decrease in the rigidity, it is conceivable that the side wall portion in which the concave portion is formed is made thick, but the second cap 22 is thereby enlarged, and as a result, the unit cells 14 are arranged closely. It becomes difficult.

  In addition, it is conceivable that the flow path of the air flow F that communicates the gap between the unit cells 14 and the bottom of the second cap 22 is constituted by a through hole instead of a recess. However, the rigidity of the side wall portion of the second cap 22 in which such a through hole is formed may be lowered. In order to suppress the decrease in the rigidity, it is conceivable that the side wall portion in which the through hole is formed is made thick, but this increases the size of the second cap 22, and as a result, the unit cell 14 is tightly packed. It becomes difficult to line up. In the case of a through hole, the processing cost of the second cap 22 is higher than that of the recess.

  In addition, since the first and second recesses 22c and 22d are in the shape of through holes, the unit cell 14 covered by the second cap 22 is placed in the flow path of the air flow F constituted by the recesses 22c and 22d. Part of the part is exposed. As a result, the portion of the unit cell 14 covered with the second cap 22 is cooled.

  Therefore, as in the present embodiment, the concave portions 22c and 22d formed in the adjacent second caps 22 are opposed to each other, so that the rigidity of the second cap 22 is maintained and the second caps 22 are maintained. The flow path of the airflow F can be formed in

  As described above, in order to form the flow path of the air flow F between the second caps 22, the first concave portion 22c and the second concave portion 22d are normally opposed to each other in the depth direction (Y-axis direction). It is necessary to attach the plurality of second caps 22 to the base portion 24 in the posture.

  In order to attach the plurality of second caps 22 to the base portion 24 in a normal posture without making a mistake in the direction of the depth direction (Y-axis direction), as shown in FIG. A protrusion 22h that protrudes in the height direction (Z-axis direction) is provided on the bottom 22a.

  Specifically, as shown in FIG. 3, when the second cap 22 is attached to the base portion 24, the two engaging portions 22 b of the second cap 22 are inserted into the two engaging holes 24 b of the base portion 24. It is inserted. Since the two engagement holes 24b are arranged in the width direction (X-axis direction), the second cap 22 may be attached to the base portion 24 in the wrong direction in the depth direction (Y-axis direction).

  In order to prevent an error in the orientation in the depth direction (Y-axis direction), the protrusion 22 h provided on the bottom portion 22 a of the second cap 22 has a base portion 24 with the second cap 22 oriented in the correct depth direction. Can be passed through the vent 24e. On the other hand, when the second cap 22 is in the wrong depth direction, the protrusion 22 h hits the battery holding portion 24 a of the base portion 24, whereby the engaging portion 22 b of the second cap 22 engages the base portion 24. The hole 24b cannot be engaged.

  By providing such a protrusion 22 h on the second cap 22, the plurality of second caps 22 are attached to the base portion 24 in a state where the first recess 22 c and the second recess 22 d are reliably opposed to each other. Can do. As a result, the flow path of the air flow F is reliably formed between the second cap 22 by the first concave portion 22c and the second concave portion 22d facing each other.

  Note that means for engaging the second cap 22 with the base portion 24 in a state in which the depth direction (Y-axis direction) is correct is not limited to the protrusion 22 h formed on the second cap 22. For example, the shape of the engagement portion 22b of the second cap 22 and the engagement hole 24b of the base portion 24 is such that the direction of the second cap 22 in the depth direction (Y-axis direction) is the first recess 22c and the second shape. A shape that can be engaged only when the concave direction 22d can be opposed to each other, for example, a triangular shape may be used.

  Furthermore, as shown in FIG. 3, the opening area of the ventilation opening 26 b of the cover portion 26 that is the outlet of the airflow F that passes through the gaps between the single cells 14 and cools the single cells 14 is set at the inlet of the airflow F. You may make it small compared with the opening area of the ventilation opening 24e of a certain base part 24. FIG.

  The opening area of the ventilation opening 26b of the cover part 26 is a size in which the user cannot touch the external terminals (the positive terminal 14a and the negative terminal 14b) of the unit cell 14 through the ventilation hole 26b, that is, a size in which the user's finger cannot pass. Has been determined. Compared with the opening area of the vent hole 26b of the cover part 26, the opening area of the vent hole 24e of the base part 24 is increased.

  As a result, a large amount of airflow F flows between the base portion 24 and the cover portion 26 via the vent 24 e of the base portion 24. Further, since the vent hole 26b of the cover part 26 serving as the outlet is smaller than the vent hole 24e of the base part 24 serving as the inlet, a part of the airflow F that has passed through the vent hole 24e of the base part 24 is immediately covered by the cover part. The air flows around the unit cell 14 without going out through the ventilation openings 26b of the 26. For example, the airflow flows through the gap between the unit cells 14 adjacent in the width direction (X-axis direction). As a result, the plurality of single cells 14 are further cooled as compared with the case where the opening area of the vent hole 26b of the cover part 26 is larger than or equal to the opening area of the vent hole 24e of the base part 24.

  According to the present embodiment, the first concave portion 22c and the second concave portion 22d formed in the second cap 22 suppress the deterioration of the cooling performance of each of the unit cells 14, and a plurality of the unit cells 14 are provided. The power storage device 10 can be made compact by arranging them closely.

  Although the present invention has been described with reference to the above-described embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the case of the above-described embodiment, as shown in FIG. 8, the first recess 22c and the second recess 22d formed in the second cap 22 have the side wall portions 22e and 22f extending from the outer surface to the inner surface. It is the form which penetrates toward. The present invention is not limited to this form.

  For example, FIG. 15 illustrates a cross-sectional view of adjacent second caps 122 in a power storage device according to another embodiment.

  As shown in FIG. 15, the first recess 122c and the second recess 122d of the second cap 122 are different from the first recess 22c and the second recess 22d of the second cap 22 of the above-described embodiment. Unlike (see, for example, FIG. 8), the side walls 122e and 122f are not penetrated from the outer surface toward the inner surface. As described above, the non-penetrating first concave portion 122c and the second concave portion 122d can also form a flow path through which the airflow F passes between the second caps 122 by facing each other. In addition, since the first recess 122c and the second recess 122d are non-penetrating, the rigidity of the second cap 122 is improved as compared with the case of penetrating.

  In the case of the above-described embodiment, as shown in FIG. 14, the first recess 22c extends from the opening end 22g of the second cap 22 to a substantially central portion in the height direction (Z-axis direction). The second concave portion 22d extends from the bottom portion 22a to a substantially central portion in the height direction, but the present invention is not limited to this. For example, both the 1st recessed part 22c and the 2nd recessed part 22d may be the same form extended from the opening end 22g of the 2nd cap 22 to the bottom part 22a.

  That is, one first recess 22c and the other second recess 22d of the adjacent second caps 22 are at least partially opposed to each other, thereby communicating with the gap between the adjacent unit cells 14. If at least one flow path of the air flow F communicating with the bottom 22a of the second cap 22 is formed, the first recess 22c and the second recess 22d formed in the second cap 22 The shape and the number thereof are not limited. Therefore, the flow path of the airflow F in the power storage device according to the embodiment of the present invention is configured by a recess formed in each of the plurality of second caps 22 in a broad sense.

  However, in consideration of securing the rigidity of the second cap 22, preferably, the first recess 22 c extends from the opening end 22 g of the second cap 22 in the height direction (Z-axis direction) as in the above-described embodiment. ) Extending approximately to the center, and the second recess 22d extends from the bottom 22a to approximately the center in the height direction, and a part of the first recess 22c and a part of the second recess 22d Are opposed to each other at a substantially central position in the height direction of the second cap 22.

  For example, in the case of the above-described embodiment, the plurality of second caps 22 attached to the plurality of single cells 14 are not in contact with each other, but the present invention is not limited to this. Even if the second caps 22 are in contact with each other, the first recess 22c and the second recess 22d face each other to form a flow path for the air flow F to pass between the second caps 22. can do. In this case, compared to the case where the second caps 22 do not contact each other, the plurality of unit cells 14 can be arranged densely, and thus the power storage device 10 can be made more compact.

  Further, for example, in the case of the above-described embodiment, the plurality of second caps 22 attached to the plurality of single cells 14 have the same shape, but the present invention is not limited to this. The plurality of second caps 22 may have different shapes.

  For example, two types of second caps are prepared, and one type of second cap and the other type of second cap are alternately arranged on the base portion. Recesses are formed on both side wall portions of one type of second cap, and recesses are formed on both side wall portions of the other type of second cap. When the concave portion of the second cap of one type and the concave portion of the second cap of the other type are opposed to each other, between the second cap of one type and the second cap of the other type, A flow path through which the airflow passes is formed.

  In addition, in the case of the above-described embodiment, for example, a plurality of second caps 22 are used to cover the lower ends of the plurality of single cells 14. However, the embodiment of the present invention is not limited to this.

  FIG. 16 is a cross-sectional view of a second cap in a power storage device according to still another embodiment.

  Only one second cap 222 shown in FIG. 16 is provided for the power storage device, and covers the lower ends of the plurality of unit cells 14. In other words, the second cap 222 has a tray shape and includes a plurality of accommodation holes 222j that accommodate and cover the lower ends of the plurality of unit cells 14.

  As shown in FIG. 16, the second cap 222 has a flow path 222m of the airflow F in a partition wall portion 222k (a portion sandwiched between lower ends of adjacent unit cells 14) that defines a plurality of receiving holes 222j. Is formed. Each of the flow paths 222m communicates with a gap between the adjacent unit cells 14 (that is, the space above the partition wall portion 222k), and the other end is the bottom portion of the second cap 222. 222a. The flow path 222m is formed in the partition wall 222k so as to alternately pass through the adjacent accommodation holes 222j. Thereby, the airflow F flowing through the flow path 222m alternately enters the adjacent accommodation holes 222j, that is, alternately contacts the adjacent unit cells 14. As a result, the lower end of the unit cell 14 covered with the accommodation hole 222j of the second cap 222 is cooled by the airflow F. The flow path 222m formed in the partition wall portion 222k may communicate with the gap between the adjacent unit cells 14 without communicating with the accommodation hole 222j.

  FIG. 17 is a cross-sectional view of a second cap and a heat insulating plate (spacer) in a power storage device according to another embodiment.

  The plurality of heat insulating plates 334 shown in FIG. 17 are arranged in the gaps between the adjacent unit cells 14. The heat insulating plate 334 includes a space between one adjacent unit cell 14 (for example, the left unit cell 14 in the drawing) and the heat insulating plate 334 and the other unit cell 14 (the unit cell 14 on the right side in the drawing). ) And the space between the heat insulating plates 334, the flow paths 334a that alternately pass through are formed. The air flow F that has passed between the second caps 22 passes through the flow path 334a of the heat insulating plate 334, so that the space between the one unit cell 14 and the heat insulating plate 334 that are adjacent to each other, and the other unit cell 14 are. And the space between the heat insulating plates 334 alternately. Thereby, the airflow F surely flows on both sides of the heat insulating plate 334 in the depth direction (Y-axis direction), and the adjacent unit cells 14 are cooled substantially equally by the airflow F.

  Thus, the cooling of the unit cell 14 by the airflow passing through the flow path of the second cap can take various forms. In a broad sense, the second cap in the power storage device according to the embodiment of the present invention has a second direction (a direction orthogonal to the first direction) in each of the plurality of unit cells arranged in the first direction. It is a cap that covers one side, and includes a plurality of flow paths that communicate with the gaps between adjacent single cells.

  Finally, in the case of the above-described embodiment, the airflow passage communicating with the gap between the adjacent unit cells is provided in the second cap that covers the lower end of the unit cell. The embodiment is not limited to this. The airflow channel may be provided in the first cap that covers the upper end portion of the unit cell, or may be provided in both the first and second caps. That is, the flow path of the airflow communicating with the gap between the adjacent unit cells is in the second direction (direction orthogonal to the first direction) in each of the plurality of unit cells arranged in the first direction. It is provided in a cap that covers one side.

  The present invention can be applied to a power storage device including a plurality of unit cells.

10 power storage device 14 cell 22 cap (second cap)
F Airflow

Claims (8)

A plurality of cells arranged in a first direction;
A cap that covers one side of a second direction orthogonal to the first direction in each of the plurality of unit cells,
The power storage device, wherein the cap includes a plurality of flow paths communicating with gaps between adjacent unit cells. The cap is a plurality of caps each covering one side of the unit cell in the second direction,
The power storage device according to claim 1, wherein each of the plurality of caps includes a recess that constitutes the flow path.   Each of the plurality of caps is formed on one side in the first direction and is formed on the other side in the first direction, and the first recess is in communication with a gap between adjacent unit cells. 3. The power storage device according to claim 2, further comprising: a second concave portion that communicates with a bottom portion of the first cap and that constitutes the flow path by partially facing a first concave portion of another adjacent cap.   The power storage device according to claim 2 or 3, wherein the plurality of caps have the same shape.   The power storage device according to any one of claims 1 to 4, wherein the cap is configured such that a part of a unit cell covered with the cap is exposed in the flow path. A base portion for holding the plurality of single cells arranged in the first direction via the cap;
The power storage device according to claim 1, wherein the base portion includes a plurality of openings facing each of the plurality of flow paths. The plurality of single cells are arranged in a plurality of rows in the first direction,
The plurality of openings communicating with the plurality of flow paths communicating with the respective gaps of the plurality of single cells in one row adjacent to each other, and the plurality of flows communicating with the respective gaps of the plurality of unit cells in the other row. The power storage device according to claim 6, wherein the plurality of openings facing the road are formed in the base portion so that the positions in the first direction are different. A base portion for holding the plurality of single cells arranged in the first direction via the plurality of caps;
Each of the plurality of caps includes an engaging portion for engaging with a base portion,
The base portion includes a plurality of engaging portions that engage with the engaging portions of the caps,
The flow path is such that the engaging portion of the cap and the engaging portion of the base portion are partially opposed to the first concave portion of one cap and the second concave portion of the other cap. The power storage device according to claim 3, wherein the power storage devices are configured to engage with each other.

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