JP7331650B2 - power storage device - Google Patents

Description

The present invention relates to a power storage device.

A power storage device having a plurality of stacked power storage modules is known (for example, Patent Document 1). In such a power storage device, a plurality of power storage modules are constrained in the stacking direction by a pair of constraining plates. In Patent Document 1, a plurality of connecting members are engaged with a plurality of engaging portions arranged along the respective edges of the restraining plates, and load is applied to the plurality of power storage modules in the stacking direction via the pair of restraining plates. are added.

JP 2018-125124 A

When the power storage module is expanded in the in-plane direction perpendicular to the stacking direction, the constraining plate must also be expanded. As the size of the constraining plate increases, the weight of the constraining plate also increases. On the other hand, when the power storage module is expanded in the in-plane direction, the distance from the engaging portion of the restraint plate to the center position of the restraint plate is also increased. In this case, if the thickness of the constraining plate in the stacking direction is reduced simply to reduce the weight, the rigidity of the constraining plate decreases, and the load applied from the connecting member to the power storage module via the constraining plate also decreases. . Therefore, it is also required to secure the load applied by the restraining plate to the power storage module by ensuring the rigidity of the restraining plate.

One aspect of the present invention provides an electric storage device in which the weight of the constraining plate is reduced while the load on the electric storage module is ensured by the constraining plate that constrains the electric storage module.

A power storage device according to one aspect of the present invention includes a plurality of stacked power storage modules, a pair of restraining plates, and a plurality of connecting members. A pair of restraint plates sandwiches the plurality of power storage modules in the stacking direction. The plurality of connecting members connect the pair of constraining plates and apply a load to the plurality of power storage modules in the stacking direction via the pair of constraining plates. Each of the pair of restraining plates has a first edge and a second edge, and has a plurality of first engaging portions and a plurality of second engaging portions. The first edge and the second edge face each other and extend in a direction intersecting the facing direction. A portion of the plurality of connecting members arranged along the first edge engages with the plurality of first engaging portions. A portion of the plurality of connecting members arranged along the second edge engages with the plurality of second engaging portions. At least one of the pair of restraint plates has a plurality of rib portions and a plurality of thin portions. The plurality of thin portions are defined by the plurality of rib portions and have a thickness in the stacking direction that is thinner than the plurality of rib portions. The plurality of rib portions includes edge rib portions, a plurality of first rib portions and a plurality of second rib portions. The edge rib portion extends along the edge of the restraining plate. The plurality of first rib portions are inclined with respect to the facing direction of the first edge and the second edge and extend on a straight line connecting the first engaging portion and the second engaging portion. Each of the plurality of second rib portions is connected to the first rib portion and extends in the opposite direction of the first edge and the second edge. Both ends of each first rib are connected to the edge rib. At least two of the plurality of first rib portions extend in mutually different directions and intersect each other. At least one of the plurality of second rib portions is connected to two first rib portions that cross each other at both ends.

In the power storage device, at least one of the pair of restraining plates has a plurality of rib portions and a plurality of thin portions having a thickness thinner than the plurality of rib portions in the stacking direction. A plurality of thinned portions are defined by a plurality of rib portions. Therefore, the rigidity of the restraining plate is ensured by the plurality of ribs while the weight of the restraining plate is reduced by the plurality of thin portions. Each first rib portion is inclined with respect to the facing direction of the first edge and the second edge and extends on a straight line connecting the first engaging portion and the second engaging portion. At least two of the plurality of first rib portions cross each other. Furthermore, each of the plurality of second rib portions is connected to the first rib portion and extends in the opposite direction of the first edge and the second edge. Both ends of some of the plurality of second rib portions are connected to the first rib portions that intersect with each other. Therefore, the second ribs act as braces for the first ribs that intersect each other. By arranging the ribs in this way, the rigidity against twisting of the restraining plate due to the force applied to the restraining plate from each connecting member via the first and second engaging portions is improved without enlarging the area of the rib. do. As a result, in the electric storage device, the weight of the constraining plate can be reduced while the load on the electric storage module is ensured by the constraining plate that constrains the electric storage module.

A plurality of first rib portions may form a plurality of intersection portions. The plurality of intersections may be arranged in a direction intersecting the opposing direction between the first edge and the second edge when viewed from the stacking direction. According to this configuration, the weight of the constraining plate can be reduced while ensuring the rigidity of the center of the constraining plate.

Each of the pair of restraint plates may have a rectangular shape with the first edge and the second edge as long sides when viewed from the stacking direction. Each first engaging portion may be positioned on a straight line extending in the opposite direction from any one of the plurality of second engaging portions. Since the load is evenly applied to the constraining plate in the longitudinal direction, the constraining plate is less likely to bend even if it receives force from the connecting member. Therefore, even if the area of the rib portion when viewed in the stacking direction is reduced, the rigidity of the restraining plate against the load applied to the power storage module is ensured.

Each of the plurality of first engaging portions and the second engaging portion has a hole that passes through the restraining plate in the stacking direction and is engaged with one of the plurality of connecting members. may have a larger area than the holes when viewed in the stacking direction. In this case, segmentation of the thin portion is suppressed, and easiness in forming the constraining plate is ensured.

The plurality of second rib portions may be provided in a compartmentalized area surrounded and defined by the plurality of first rib portions. In this case, the rigidity of the restraining plate is further improved.

A plurality of second rib portions may be provided in each of the plurality of partitioned regions. The plurality of partitioned areas may include a first area and a second area. The second region may be located closer to the center of the constraining plate than the first region in a direction intersecting the opposing direction when viewed from the stacking direction. The density of thinned portions within the first region may be greater than the density of thinned portions within the second region. In order to appropriately bind the plurality of power storage modules, it is important to ensure the rigidity of the center of the binding plate. According to this configuration, the weight of the constraining plate can be reduced while ensuring the rigidity of the center of the constraining plate.

In the partitioned region, the density of the thinned portions in the first portion in the partitioned region is such that the thinned portion in the second portion located closer to the center of the restraint plate than the first portion in the partitioned region in the direction intersecting the facing direction may be greater than the density of According to this configuration, the weight of the constraining plate can be further reduced while ensuring the rigidity of the center of the constraining plate.

Each of the pair of restraining plates may have a third edge and a fourth edge and may have a third engaging portion and a fourth engaging portion. The third and fourth edges may intersect the first and second edges and extend in directions along each other. A third engagement portion may be disposed along the third edge and engaged by a portion of the plurality of connecting members. A fourth engagement portion may be disposed along the fourth edge and engaged by a portion of the plurality of connecting members. The plurality of rib portions includes edge rib portions and corner rib portions. The edge rib portion may extend along the edge of the constraining plate. The corner rib portion is slanted with respect to the first edge and the third edge. The corner rib portion may extend to connect the edge rib portion extending along the first edge and the edge rib portion extending along the third edge. In this case, the restraining plate is less likely to bend even if it receives force from the connecting member. Therefore, even if the area of the rib portion when viewed in the stacking direction is reduced, the rigidity of the restraining plate against the load applied to the power storage module is ensured.

The plurality of rib portions includes auxiliary rib portions. The auxiliary rib portion is inclined with respect to the facing direction of the first edge and the second edge, and extends from the edge rib portion to the first rib portion on a straight line connecting the first engaging portion and the second engaging portion. extended. When the number of the first ribs is large, the rigidity of the restraining plate is improved compared to when the number of the first ribs is small. The shape becomes finer. It is difficult to mold a constraining plate having thin portions that are too thin. By arranging the auxiliary rib portion, it is possible to achieve a balance between improving the rigidity of the restraining plate against the load applied to the power storage module, suppressing an increase in the weight of the restraining plate, and suppressing segmentation of the thin portion.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, it is possible to provide an electric storage device in which the weight of the constraining plate is reduced while the load on the electric storage module is ensured by the constraining plate that constrains the electric storage module.

1 is a schematic perspective view of a power storage device according to an embodiment; FIG. 2 is a schematic cross-sectional view of the power storage device of FIG. 1; FIG. It is a top view of a constraining board. It is a partial cross-sectional view of a restraining plate and a connecting member. FIG. 5 is a plan view of a restraint plate of a power storage device according to a modification of the embodiment; FIG. 5 is a perspective view of a restraining plate of a power storage device according to a modification of the embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and overlapping descriptions are omitted.

An embodiment of a power storage device will be described with reference to FIGS. 1 to 4. FIG. Power storage device 10 shown in FIGS. 1 and 2 is used as a battery for various vehicles such as forklifts, hybrid vehicles, and electric vehicles. The power storage device 10 includes a plurality of (three in this embodiment) power storage modules 12 , but may include a single power storage module 12 . The power storage module 12 is a bipolar battery. Electricity storage module 12 is, for example, a secondary battery such as a nickel-hydrogen secondary battery or a lithium-ion secondary battery, but may be an electric double layer capacitor. In the following description, a nickel-metal hydride secondary battery is exemplified.

A plurality of power storage modules 12 may be stacked via a conductive plate 14 such as a metal plate, for example. Hereinafter, when simply referred to as the “stacking direction”, the “stacking direction” means the stacking direction of the plurality of power storage modules 12 . When viewed from the stacking direction, the power storage modules 12 and the conductive plates 14 have, for example, a rectangular shape.

In the present embodiment, each power storage module 12 has a plurality of bipolar electrodes and separators laminated together. A separator is disposed between the bipolar electrodes adjacent to each other. Each bipolar electrode has an electrode plate, a positive electrode provided on one side of the electrode plate, and a negative electrode provided on the other side of the electrode plate. In other words, the positive electrode, the electrode plate, and the negative electrode are laminated in each bipolar electrode, and the electrode plate of each bipolar electrode is sandwiched between the positive electrode and the negative electrode. The stacking direction of the plurality of bipolar electrodes and separators and the stacking direction of the positive electrodes, electrode plates, and negative electrodes in each bipolar electrode are the same as the stacking direction of the plurality of power storage modules 12 .

The conductive plates 14 are also arranged outside the power storage modules 12 positioned at both ends in the stacking direction (Z direction) of the power storage modules 12 . The conductive plate 14 is electrically connected to adjacent power storage modules 12 . Thereby, the plurality of power storage modules 12 are connected in series in the stacking direction. A positive electrode terminal 24 is connected to the conductive plate 14 positioned at one end in the stacking direction, and a negative electrode terminal 26 is connected to the conductive plate 14 positioned at the other end. The positive terminal 24 may be integrated with the conductive plate 14 connected to the positive terminal 24 . The negative terminal 26 may be integrated with the conductive plate 14 connected to the negative terminal 26 . The positive terminal 24 and the negative terminal 26 extend in a direction (X direction) crossing the stacking direction. The power storage device 10 can be charged and discharged by the positive terminal 24 and the negative terminal 26 .

The conductive plate 14 can also function as a radiator plate for releasing heat generated in the power storage module 12 . Coolants such as air and gas pass through the plurality of gaps 14 a provided inside the conductive plate 14 , so that heat from the power storage module 12 can be efficiently released to the outside. Each gap 14a extends, for example, in a direction (Y direction) intersecting the stacking direction. The conductive plate 14 is smaller than the power storage module 12 when viewed from the stacking direction, but may be the same size as the power storage module 12 or larger than the power storage module 12 .

The power storage device 10 includes a restraining member 16 that restrains the alternately stacked power storage modules 12 and the conductive plates 14 in the stacking direction. The restraining member 16 includes a pair of restraining plates 17 and 18 and a plurality of connecting members 19 that connect the restraining plates 17 and 18 together. A pair of restraint plates 17 and 18 sandwich the plurality of power storage modules 12 in the stacking direction. An insulating film 22 such as a resin film is arranged between each of the restraint plates 17 and 18 and the conductive plate 14 . Each of the restraining plates 17 and 18 and the insulating film 22 has, for example, a rectangular shape when viewed from the stacking direction. The insulating film 22 is larger than the conductive plate 14 and each constraining plate 17 , 18 is larger than the power storage module 12 .

The constraining plate 17 has a major surface 17a and a major surface 17b located on the opposite side of the major surface 17a. The constraining plate 18 has a principal surface 18a and a principal surface 18b located on the opposite side of the principal surface 18a. The principal surface 17b and the principal surface 18b face each other. Each restraint plate 17, 18 is made of metal such as iron or aluminum.

The main surface 17b of the constraining plate 17 abuts against the conductive plate 14 connected to the negative terminal 26 via the insulating film 22, and the main surface 18b of the constraining plate 18 contacts the conductive plate 14 connected to the positive terminal 24. They are abutted through an insulating film 22 . In this state, the pair of restraint plates 17 and 18 are connected to each other by the connecting member 19 . As a result, the insulating film 22, the conductive plate 14, and the power storage module 12 are sandwiched and unitized, and a restraining load is applied in the stacking direction. In other words, the connecting member 19 applies a load to the plurality of power storage modules 12 in the stacking direction via the pair of restraining plates 17 and 18 .

Each of the restraining plates 17 and 18 has a pair of edges 31a and 31b facing each other and extending in a direction intersecting the facing direction, and a pair of edges 31a and 31b extending in a direction intersecting the pair of edges 31a and 31b. It has edges 31c and 31d. In this embodiment, each of the restraining plates 17 and 18 has a substantially rectangular shape in plan view, and the pair of edges 31a and 31b extend parallel to each other. Also, the pair of edges 31c and 31d extend parallel to each other. Viewed from the stacking direction, in the constraining plate 17, the edges 31a, 31b, 31c, 31d define a main surface 17a. Viewed from the stacking direction, in the constraining plate 18, the edges 31a, 31b, 31c, 31d define a major surface 18a. For example, edges 31c and 31d are parallel to each other and perpendicular to the pair of edges 31a and 31b. Edge 31c is connected to one end of edge 31a and edge 31b, and edge 31d is connected to the other end of edge 31a and edge 31b. In the rectangular constraining plates 17 and 18, the edges 31a and 31b constitute the long sides, and the edges 31c and 31d constitute the short sides. Edge 31a corresponds to, for example, the first edge. The edge 31b corresponds to, for example, the second edge. The edge 31c corresponds to the third edge, for example. Edge 31d corresponds to, for example, the fourth edge.

The restraining member 16 will be described in more detail below with reference to FIGS. 3 and 4. FIG. FIG. 3 is a plan view of the restraining plate 17. FIG. FIG. 4 is a partial cross-sectional view of the restraining plate 17. As shown in FIG. In this embodiment, the constraining plate 17 and the constraining plate 18 have the same structure. Each restraining plate 17 , 18 has a plurality of engaging portions 32 , 33 , 34 , 35 that respectively engage with the plurality of connecting members 19 . The engagement portions 32, 33, 34, 35 are arranged along the edges 31a, 31b, 31c, 31d respectively. In the restraining plate 17, the engaging portions 32, 33, 34, 35 are provided on the main surface 17a. In the restraining plate 18, the engaging portions 32, 33, 34, 35 are provided on the main surface 18a. The engaging portion 32 corresponds, for example, to the first engaging portion. The engaging portion 33 corresponds to, for example, the second engaging portion. The engaging portion 34 corresponds to, for example, the third engaging portion. The engaging portion 35 corresponds to, for example, the fourth engaging portion.

The plurality of engaging portions 32 of the restraining plate 17 and the plurality of engaging portions 32 of the restraining plate 18 are arranged at positions overlapping each other when viewed from the stacking direction. The plurality of engaging portions 33 of the restraining plate 17 and the plurality of engaging portions 33 of the restraining plate 18 are arranged at positions overlapping each other when viewed from the stacking direction. The engaging portion 34 of the constraining plate 17 and the engaging portion 34 of the constraining plate 18 are arranged to overlap each other when viewed from the stacking direction. The engaging portion 35 of the constraining plate 17 and the engaging portion 35 of the constraining plate 18 are arranged to overlap each other when viewed from the stacking direction.

In each of the restraining plates 17 and 18, the plurality of engaging portions 32 and the plurality of engaging portions 33 are arranged in line-symmetrical positions with respect to an imaginary line passing through the midpoint of the facing direction of the edges 31a and 31b. there is In other words, each of the plurality of engaging portions 32 is provided so as to be positioned on a straight line extending from one of the plurality of engaging portions 33 in the facing direction of the edges 31a and 31b. there is That is, each of the plurality of engaging portions 32 provided along the edge 31a faces one of the plurality of engaging portions 33 provided along the edge 31b in a direction orthogonal to the edges 31a and 31b. lined up in the direction

In this embodiment, the plurality of engaging portions 32 includes five engaging portions 32a, 32b, 32c, 32d, and 32e, which are evenly spaced along the edge 31a. The engaging portion 32a is arranged at one end of the edge 31a and the engaging portion 32e is arranged at the other end of the edge 31a. In other words, the engaging portions 32a and 32e are the engaging portions of the plurality of engaging portions 32 that are closest to the end of the edge 31a. Engagement portions 32b, 32c, 32d are arranged along edge 31a between engagement portion 32a and engagement portion 32e in that order.

In this embodiment, the plurality of engaging portions 33 includes five engaging portions 33a, 33b, 33c, 33d, and 33e, which are evenly spaced along the edge 31b. The engaging portion 33a is arranged at one end of the edge 31b and the engaging portion 33e is arranged at the other end of the edge 31b. In other words, the engaging portions 33a and 33e are the engaging portions closest to the end of the edge 31b among the plurality of engaging portions 33. As shown in FIG. Engagement portions 33b, 33c, 33d are arranged along edge 31b between engagement portion 33a and engagement portion 33e in that order.

The engaging portion 34 is sandwiched between the engaging portion 32a and the engaging portion 33a. Engagement portions 32a, 34, 33a are arranged along edge 31c in the indicated order. The engaging portion 35 is sandwiched between the engaging portion 32e and the engaging portion 33e. Engagement portions 32e, 35, 33e are arranged along edge 31d in the indicated order.

Each of the engaging portions 32 , 33 , 34 , 35 of the constraining plate 17 is provided with a through hole H<b>1 passing through the constraining plate 17 in the stacking direction. Each of the engaging portions 32, 33, 34, 35 of the constraining plate 18 is provided with a through hole H2 penetrating the constraining plate 18 in the stacking direction (see FIG. 2). The through holes H1 and H2 are provided outside the power storage module 12 when viewed in the stacking direction. A plurality of connecting members 19 engage with the through holes H1 and H2, respectively.

Each of the plurality of connecting members 19 has a bolt 19a including a shaft extending in the stacking direction and a nut 19b screwed onto the bolt 19a. A shaft portion of the bolt 19a is inserted through each of the through holes H1 and H2. The head of the bolt 19a is arranged on the principal surface 17a of the restraining plate 17, and the screw tip of the bolt 19a protrudes from the principal surface 18a of the restraining plate 18. As shown in FIG. A nut 19b is screwed onto the threaded end of the bolt 19a. The nut 19b is arranged on the main surface 18a of the restraining plate 18. As shown in FIG. The bolts 19a and nuts 19b of the plurality of connecting members 19 apply a load to the plurality of power storage modules 12 in the stacking direction via the pair of restraint plates 17 and 18 .

Each restraining plate 17 , 18 has a plurality of rib portions 38 and a plurality of thin portions 39 . Each of the plurality of thinned portions 39 is defined by a plurality of rib portions 38 . As shown in FIG. 4, the thickness of each thin portion 39 is thinner than the thickness of the plurality of rib portions 38 and the thickness of the plurality of engaging portions 32, 33, 34, 35 in the stacking direction. In this embodiment, the minimum thickness T1 of each rib portion 38 is 15 mm or more and 25 mm or less. A minimum thickness T2 of each thin portion 39 is 2 mm or more and 7 mm or less. A minimum thickness T3 of each engaging portion 32, 33, 34, 35 is more than 7 mm and 20 mm or less. Each thin portion 39 has an area larger than that of the through holes H1 and H2 when viewed in the stacking direction. When viewed from the stacking direction, the area of each thin portion 39 should be 19 mm ² or more. In this embodiment, the area of each thin portion 39 is 19.6 mm ² or more when viewed from the stacking direction.

A plurality of rib portions 38 and a plurality of thin portions 39 are provided on the principal surface 17 a of the restraining plate 17 and the principal surface 18 a of the restraining plate 18 . A principal surface 17b of the restraint plate 17 and a principal surface 18b of the restraint plate 18 are flat surfaces. In this embodiment, the width of each rib portion 38 is the same when viewed from the stacking direction. The width of each rib portion 38 is the length of each rib portion 38 in the direction orthogonal to the extending direction of the rib portion 38 and the stacking direction.

The plurality of rib portions 38 includes a plurality of first rib portions 41, a plurality of second rib portions 42, an edge rib portion 43, a central rib portion 44, a plurality of corner rib portions 45, a plurality of auxiliary rib portions 46, and a plurality of An adjustment rib portion 47 is included. Each first rib portion 41 is inclined with respect to the facing direction of the edges 31 a and 31 b and extends on a straight line connecting the engaging portion 32 and the engaging portion 33 . Both ends of each first rib portion 41 are connected to the edge rib portion 43 respectively. At least two of the plurality of first rib portions 41 form intersecting portions 48 that extend in mutually different directions and cross each other.

In this embodiment, the multiple first rib portions 41 form multiple crossing portions 48 . The plurality of intersections 48 are arranged between the edges 31a and 31b in a direction that intersects the facing direction of the edges 31a and 31b when viewed from the stacking direction. In this embodiment, since the plurality of engaging portions 32 and the plurality of engaging portions 33 are provided so as to line up in the facing direction, the plurality of engaging portions 32a and 31b extending obliquely with respect to the edges 31a and 31b are provided. The first rib portions 41 intersect the restraining plates 17 and 18 at their central portions.

In this embodiment, both ends of each first rib portion 41 are connected to any two of the plurality of engaging portions 32 , 33 , 34 , 35 . A plurality of first rib portions 41 define a plurality of partitioned regions 51 , 52 , 53 . The partitioned regions 51, 52, 53 are substantially rhombic when viewed from the stacking direction. The partitioned areas 51 and 53 correspond to the first area, for example. The partitioned area 52 corresponds to, for example, the second area.

In this embodiment, the multiple first rib portions 41 include eight first rib portions 41a, 41b, 41c, 41d, 41e, 41f, 41g, and 41h. Both ends of the first rib portion 41 a are connected to the engaging portion 32 b and the engaging portion 34 . Both ends of the first rib portion 41b are connected to the engaging portion 32b and the engaging portion 33c. Both ends of the first rib portion 41c are connected to the engaging portion 32c and the engaging portion 33b. Both ends of the first rib portion 41d are connected to the engaging portion 32c and the engaging portion 33d. Both ends of the first rib portion 41e are connected to the engaging portion 32d and the engaging portion 33c. Both ends of the first rib portion 41 f are connected to the engaging portion 32 d and the engaging portion 35 . Both ends of the first rib portion 41 g are connected to the engaging portion 33 b and the engaging portion 34 . Both ends of the first rib portion 41 h are connected to the engaging portion 33 d and the engaging portion 35 .

In this embodiment, the partitioned area 51 is surrounded and defined by the first rib portions 41a, 41b, 41c, and 41g. A partitioned region 52 is surrounded and defined by the first rib portions 41b, 41c, 41d, and 41e. A partitioned region 53 is surrounded and defined by the first rib portions 41d, 41e, 41f, and 41h. As used herein, an "enclosed and defined" region refers to a region in which 70% or more of the edge of the region is defined by a plurality of ribs.

When viewed from the stacking direction, the partitioned region 52 is positioned closer to the center of the restraint plates 17, 18 than the partitioned regions 51, 53 in the direction intersecting the facing direction of the edges 31a and 31b. The "center" is equidistant from both ends of the edge 31c when viewed from a direction orthogonal to the facing direction of the edges 31a and 31b, and viewed from a direction orthogonal to the facing direction of the edges 31c and 31d. In this case, it means a position equidistant from both ends of the edge 31a.

The plurality of second rib portions 42 are provided in each of the plurality of partitioned regions 51 , 52 , 53 that are surrounded and defined by the plurality of first rib portions 41 . In other words, a plurality of second rib portions 42 extend in each of the partitioned regions 51, 52, 53. As shown in FIG. Both ends of some of the plurality of second rib portions 42 are connected to the first rib portions 41 that intersect with each other. Each second rib portion 42 extends in a direction different from that of the plurality of first rib portions 41 . Each second rib portion 42 is connected to the first rib portion 41 and extends in the facing direction of the edges 31a and 31b. In this embodiment, all of the plurality of second rib portions 42 extend in a direction orthogonal to the edges 31a and 31b.

The density of the thin portions 39 in the partitioned regions 51 and 53 is higher than the density of the thin portions 39 in the partitioned region 52 . In other words, the density of the rib portions 38 provided in the partitioned regions 51 and 53 is lower than the density of the rib portions 38 provided in the partitioned region 52 when viewed from the stacking direction. In this embodiment, the density of the second rib portions 42 within the partitioned regions 51 and 53 is lower than the density of the second rib portions 42 within the partitioned region 52 . "Density" refers to a value obtained by dividing the total area of objects in a partitioned region by the area of the partitioned region when viewed in the stacking direction. For example, the "density of thin portions" refers to a value obtained by dividing the total area of a plurality of thin portions in each partitioned region by the area of the partitioned region when viewed in the stacking direction.

In each of the partitioned regions 51, 52, 53, the thickness of the thin portion 39 in each of the partitioned regions 51, 52, 53 increases toward the center of the restraining plates 17, 18 in the direction intersecting the facing direction of the edges 31a and 31b. It is designed for low density. In other words, the density of the thin portions 39 in the first portion in each of the partitioned regions 51, 52, 53 is the same as that in the partitioned regions 51, 52, 53 in the direction intersecting the facing direction of the edges 31a and 31b. The density of the thinned portions 39 in the second portion located closer to the center of the constraining plates 17, 18 than in the portion is greater. In the present embodiment, in each of the partitioned regions 51, 52, 53, in the direction along the edge 31a, as the center of the constraining plates 17, 18 is approached, the second The distance between rib portions 42 is narrowed.

The edge rib portion 43 extends along the edges 31a, 31b, 31c, 31d of the restraining plates 17, 18. As shown in FIG. When viewed from the stacking direction, the edge rib portion 43 surrounds the rib portions 38 other than the edge rib portion 43 among the plurality of rib portions 38 . The edge rib portion 43 includes an edge rib portion 43a and an edge rib portion 43b.

In this embodiment, the edge rib portion 43a is included in the engagement portions 32, 33, 34, 35 and constitutes the edges of the engagement portions 32, 33, 34, 35, respectively. The through holes H1 and H2 are surrounded by the edge rib portion 43a. The edge rib portion 43b is linear when viewed from the stacking direction. The edge rib portion 43b connects the engaging portions 32, 33, 34, 35 adjacent to each other along the edges 31a, 31b, 31c, 31d. Of the plurality of ribs 38, only edge ribs 43 are connected to the engaging portions 32a, 32e, 33a, 33e. The first rib portion 41 is not connected to the engaging portions 32a, 32e, 33a, 33e.

The central rib portion 44 extends in a direction along the edge 31a. Both ends of the central rib portion 44 are connected to the engaging portion 34 and the engaging portion 35 .

In the restraining plates 17 and 18 , a plurality of partitioned regions 54 are surrounded and defined by the edge rib portion 43 and the first rib portion 41 . A plurality of partitioned areas 54 are located outside the partitioned areas 51 , 52 , 53 . The partitioned area 54 corresponds to, for example, the third area. The plurality of partitioned regions 54 includes two partitioned regions 54a defined by the edge rib portion 43 and the first rib portions 41b and 41c, and two partition regions 54a defined by the edge rib portion 43 and the first rib portions 41d and 41e. and a partitioned area 54b.

The plurality of partitioned areas 54 further includes partitioned areas 54c, partitioned areas 54d, partitioned areas 54e, and partitioned areas 54f. The partition region 54c is surrounded and defined by the edge rib portion 43 and the first rib portion 41a. The partitioned region 54d is surrounded and defined by the edge rib portion 43 and the first rib portion 41f. The partitioned region 54e is surrounded and defined by the edge rib portion 43 and the first rib portion 41g. The partitioned region 54f is surrounded and defined by the edge rib portion 43 and the first rib portion 41h. The partitioned areas 54c, 54d are located closer to the ends of the edge 31a than the partitioned areas 51, 52, 53 are. The partitioned regions 54e, 54f are located closer to the ends of the edge 31b than the partitioned regions 51, 52, 53 are.

The plurality of corner rib portions 45 are provided in the partitioned regions 54c, 54d, 54e, and 54f when viewed from the stacking direction. A plurality of square rib portions 45 are provided in each of the partitioned regions 54c, 54d, 54e, and 54f. The plurality of corner rib portions 45 are inclined with respect to the edges 31a, 31b, 31c and 31d.

Both ends of the plurality of corner rib portions 45 provided in the partitioned region 54c are connected to edge rib portions 43b provided along the edge 31a and edge rib portions 43b provided along the edge 31c. . Both ends of the plurality of corner rib portions 45 provided in the partitioned region 54d are connected to edge rib portions 43b provided along the edge 31a and edge rib portions 43b provided along the edge 31d. . Both ends of the plurality of corner rib portions 45 provided in the partitioned region 54e are connected to edge rib portions 43b provided along the edge 31b and edge rib portions 43b provided along the edge 31c. . Both ends of the plurality of corner rib portions 45 provided in the partitioned region 54f are connected to edge rib portions 43b provided along the edge 31b and edge rib portions 43b provided along the edge 31d. .

The density of the thin portions 39 in the partitioned regions 54c, 54d, 54e, and 54f is higher than the density of the thin portions 39 in the partitioned regions 51, 52, and 53 when viewed from the stacking direction. In other words, the density of the plurality of rib portions 38 provided in the partitioned regions 54c, 54d, 54e, and 54f when viewed from the stacking direction is the same as that of the plurality of ribs provided in the partitioned regions 51, 52, and 53. less than the density of the portion 38; In this embodiment, the density of the corner rib portions 45 in the partitioned regions 54c, 54d, 54e, and 54f is lower than the density of the second rib portions 42 in the partitioned regions 51, 52, and 53. FIG.

A plurality of auxiliary rib portions 46 are provided in a plurality of partitioned regions 54a and 54b. Each auxiliary rib portion 46 is inclined with respect to the facing direction of the edges 31 a and 31 b and extends on a straight line connecting the engaging portions 32 and 33 . Each auxiliary rib portion 46 extends from the edge rib portion 43 to the first rib portion 41 . Both ends of each of the plurality of auxiliary rib portions 46 are connected to one of the plurality of engaging portions 32 and 33 and one of the plurality of first rib portions 41 . Each of the plurality of auxiliary rib portions 46 extends in a direction different from the first rib portion 41 extending from the engaging portions 32 and 33 to which the auxiliary rib portions 46 are connected. The plurality of auxiliary rib portions 46 include auxiliary rib portions 46a, 46b, 46c, 46d, 46e, 46f, 46g and 46h.

The auxiliary rib portion 46a extends from the engagement portion 32b toward the edge 31b to the first rib portion 41c. The auxiliary rib portion 46b extends from the engaging portion 32c toward the edge 31b to the first rib portion 41b. The auxiliary rib portion 46c extends from the engaging portion 32c toward the edge 31b to the first rib portion 41e. The auxiliary rib portion 46d extends from the engaging portion 32d toward the edge 31b to the first rib portion 41d. The auxiliary rib portion 46e extends from the engaging portion 33b toward the edge 31a to the first rib portion 41b. The auxiliary rib portion 46f extends from the engagement portion 33c toward the edge 31a to the first rib portion 41c. The auxiliary rib portion 46g extends from the engaging portion 33c toward the edge 31a to the first rib portion 41d. The auxiliary rib portion 46h extends from the engagement portion 33d toward the edge 31a to the first rib portion 41e.

The auxiliary rib portion 46a extends toward the engaging portion 33d. The auxiliary rib portion 46b extends toward the engaging portion 33a. The auxiliary rib portion 46c extends toward the engagement portion 33e. The auxiliary rib portion 46d extends toward the engagement portion 33b. The auxiliary rib portion 46e extends toward the engaging portion 32d. The auxiliary rib portion 46f extends toward the engagement portion 32a. The auxiliary rib portion 46g extends toward the engagement portion 32e. The auxiliary rib portion 46h extends toward the engagement portion 32b.

A plurality of adjustment rib portions 47 are provided in a plurality of partitioned regions 54a and 54b. Each of the plurality of adjustment rib portions 47 extends in a direction perpendicular to the edges 31a and 31b. Both ends of the plurality of adjustment rib portions 47 are connected to the edges 31 a and 31 b and the auxiliary rib portion 46 or connected to the auxiliary rib portion 46 and the first rib portion 41 . The density of the thin portions 39 in the plurality of partitioned regions 54 a and 54 b is higher than the density of the thin portions 39 in the partitioned region 52 when viewed from the stacking direction. In other words, the density of the plurality of rib portions 38 provided in the plurality of partitioned regions 54 a and 54 b is higher than the density of the plurality of rib portions 38 provided in the partitioned region 52 when viewed from the stacking direction. small.

Next, with reference to FIG. 5, the structure of the restraint plate 117 according to the modified example of this embodiment will be described. The constraining plate 117 in this modification is generally similar or the same as the constraining plates 17, 18 according to the above-described embodiments. The constraining plate 117 in this modified example differs from the constraining plates 17 and 18 in the above-described embodiment in that the engaging portions 34 and 35 are not provided and the plurality of rib portions 38 are accordingly changed. differ from Differences between the constraining plates 17 and 18 in the above-described embodiment and the constraining plate 117 in this modified example will be mainly described below.

In this modified example, the restraining plate 117 is not provided with the engaging portions 34 and 35 . The multiple rib portions 38 include multiple first rib portions 61 , multiple second rib portions 62 , edge rib portions 43 , and adjustment rib portions 64 . Each first rib portion 61 is inclined with respect to the facing direction of the edges 31 a and 31 b and extends on a straight line connecting the engaging portion 32 and the engaging portion 33 . Both ends of each first rib portion 61 are connected to the edge rib portion 43 respectively. At least two of the plurality of first rib portions 61 form intersection portions 68 that extend in mutually different directions and intersect each other.

Also in this modified example, the plurality of first rib portions 61 form a plurality of crossing portions 68 . The plurality of intersections 68 are arranged between the edges 31a and 31b in a direction that intersects the facing direction of the edges 31a and 31b when viewed from the stacking direction. Both ends of each first rib portion 61 are connected to any two of the plurality of engaging portions 32 and 33 in this modified example as well. Also in this modified example, the plurality of engaging portions 32 and the plurality of engaging portions 33 are provided so as to be aligned in the facing direction, so that the plurality of engaging portions 31a and 31b extend so as to be inclined with respect to the edges 31a and 31b. , intersect at the center of the constraining plate 117 .

In this modification, the plurality of first rib portions 61 includes eight first rib portions 61a, 61b, 61c, 61d, 61e, 61f, 61g, 61h. Both ends of the first rib portion 61a are connected to the engaging portion 32a and the engaging portion 33b. Both ends of the first rib portion 61b are connected to the engaging portion 32b and the engaging portion 33a. Both ends of the first rib portion 61c are connected to the engaging portion 32b and the engaging portion 33c. Both ends of the first rib portion 61d are connected to the engaging portion 32c and the engaging portion 33b. Both ends of the first rib portion 61e are connected to the engaging portion 32c and the engaging portion 33d. Both ends of the first rib portion 61f are connected to the engaging portion 32d and the engaging portion 33c. Both ends of the first rib portion 61g are connected to the engaging portion 32d and the engaging portion 33e. Both ends of the first rib portion 61h are connected to the engaging portion 32e and the engaging portion 33d.

In this modification, the partitioned area 71 is surrounded and defined by the first rib portions 61a, 61b, 61c, and 61d. A partitioned region 72 is surrounded and defined by the first rib portions 61c, 61d, 61e, and 61f. A partitioned region 73 is surrounded and defined by the first rib portions 61e, 61f, 61g, and 61h. A partitioned region 74 is surrounded and defined by the first rib portions 61a and 61b and the edge rib portion 43 along the edge 31c. A partitioned region 75 is surrounded and defined by the first rib portions 61g and 61h and the edge rib portion 43 along the edge 31d. When viewed from the stacking direction, the partitioned region 72 is positioned closer to the center of the restraint plate 117 than the partitioned regions 71 and 73 in the direction intersecting the facing direction of the edges 31a and 31b. The partitioned regions 71, 72, 73 are substantially rhombic when viewed from the stacking direction. The partitioned areas 71 and 73 correspond to the first area, for example. The partitioned area 72 corresponds to, for example, the second area.

The plurality of second rib portions 62 are provided in each of the plurality of partitioned regions 71 , 72 , 73 , 74 , 75 that are surrounded and defined by the plurality of first rib portions 61 . In other words, a plurality of second rib portions 62 extend in each of the partitioned regions 71, 72, 73, 74, 75. As shown in FIG. Both ends of some of the plurality of second rib portions 62 are connected to the first rib portions 61 that intersect with each other. Each second rib portion 62 extends in a direction different from that of the plurality of first rib portions 61 . Each second rib portion 62 is connected to the first rib portion 61 and extends in the facing direction of the edges 31a and 31b. In this modification, all of the plurality of second rib portions 62 extend in a direction perpendicular to the edges 31a and 31b.

The density of the thin portions 39 in the partitioned regions 71, 72, 73 is the same. As in the embodiment described above, the density of the thin portions 39 within the partitioned regions 71 and 73 may be configured to be greater than the density of the thin portions 39 within the partitioned region 72 . In this modification, in each of the partitioned regions 71, 72, 73, 74, 75, the distance between the second rib portions 42 adjacent to each other is constant in the direction along the edge 31a.

In the restraining plate 117, a plurality of partitioned areas 76 are surrounded and defined by the edge rib portion 43 and the first rib portion 61 along the edges 31a and 31b. A plurality of partitioned areas 76 are positioned outside the partitioned areas 71 , 72 , 73 , 74 , 75 . The density of the thin portions 39 within the partitioned region 76 is greater than the density of the thin portions 39 within the partitioned regions 71 , 72 , 73 , 74 , 75 .

The plurality of partitioned areas 76 includes two partitioned areas 76a, two partitioned areas 76b, two partitioned areas 76c, and two partitioned areas 76d. The two partitioned areas 76a are surrounded and defined by the edge rib portions 43 along the edges 31a, 31b and the first rib portions 61a, 61b. The two partitioned regions 76b are surrounded and defined by the edge rib portion 43 and the first rib portions 61c and 61d. The two partitioned areas 76c are surrounded and defined by the edge rib portion 43 and the first rib portions 61e and 61f. The two partitioned regions 76d are surrounded and defined by the edge rib portion 43 and the first rib portions 61g and 61h.

A plurality of adjustment rib portions 64 are provided in a plurality of partitioned regions 76a, 76b, 76c, and 76d. The plurality of adjustment rib portions 64 include adjustment rib portions 64a extending in a direction perpendicular to the edge 31a and adjustment rib portions 64b extending in a direction along the edge 31a. The density of the thin portions 39 within the plurality of partitioned regions 76 is greater than the density of the thin portions 39 within the partitioned regions 71 , 72 , 73 , 74 and 75 . In other words, the density of the plurality of rib portions 38 provided in the plurality of partitioned regions 76 is higher than the density of the plurality of rib portions 38 provided in the partitioned regions 71 , 72 , 73 , 74 , and 75 . small.

Next, with reference to FIG. 6, the structure of the restraining plate 217 according to the modified example of this embodiment will be described. The constraining plate 217 in this modification is generally similar or the same as the constraining plate 117 according to the modification described above. The constraining plate 217 in this modified example differs from the constraining plate 117 in the above-described modified example in that the constraining plate 217 has a U-shaped cross section and that the plurality of rib portions 38 are changed accordingly. differ. Differences between the constraining plate 117 in the modified example described above and the constraining plate 217 in the present modified example will be mainly described below.

In the constraining plate 217, the plurality of engaging portions 32 and 33 protrude in the stacking direction toward the other constraining plate that forms a pair. In the restraining plate 217 , the plurality of rib portions 38 has a plurality of first rib portions 61 , a plurality of second rib portions 62 , edge rib portions 83 and adjustment rib portions 64 . In this modification, both ends of each first rib portion 61 are connected to the edge rib portion 83 respectively. Both ends of each first rib portion 61 are not directly connected to the engaging portions 32 and 33 .

In the restraining plate 217, the edge rib portion 83 extends along the edges 31a, 31b, 31c, 31d. When viewed from the stacking direction, the edge rib portion 83 surrounds the rib portions 38 other than the edge rib portion 83 among the plurality of rib portions 38 . When viewed from the stacking direction, the width of the edge rib portion 83 provided along the edge 31a and the edge 31b is greater than the width of the edge rib portion 83 provided along the edge 31c and the edge 31d. When viewed from the stacking direction, the width of the edge rib portion 83 provided along the edge 31a and the edge 31b is larger than the width of the rib portion 38 other than the edge rib portion 83. As shown in FIG. The width of the edge rib portion 83 means the length of the edge rib portion 83 in the direction orthogonal to the extending direction of each edge rib portion 83 and the stacking direction. In the restraining plate 217, the edge rib portion 83 is located between the plurality of engaging portions 32, 33 when viewed from the stacking direction.

In the restraining plate 217, the partitioned area 74 is surrounded and defined by the first rib portions 61a and 61b and the edge rib portion 83 along the edge 31c. A partitioned region 75 is surrounded and defined by the first rib portions 61g and 61h and the edge rib portion 83 along the edge 31d.

In the restraining plate 217, a plurality of partitioned areas 76 are surrounded and defined by the edge rib portion 83 and the first rib portion 61 along the edges 31a and 31b. A plurality of partitioned areas 76 are positioned outside the partitioned areas 71 , 72 , 73 , 74 , 75 . The plurality of partitioned areas 76 includes two partitioned areas 76a, two partitioned areas 76b, two partitioned areas 76c, and two partitioned areas 76d. The two partitioned areas 76a are surrounded and defined by the edge rib portions 83 along the edges 31a, 31b and the first rib portions 61a, 61b. More specifically, a substantially triangular region surrounded by a portion extending from the engagement portion 32a to the engagement portion 32b of the edge rib portion 83 along the edge 31a and the first rib portions 61a and 61b that intersect with each other. , and a portion extending from the engagement portion 33a to the engagement portion 33b of the edge rib portion 83 along the edge 31b, and the first rib portions 61a and 61b that intersect with each other. It is Similarly, the two partitioned regions 76b are defined as two substantially triangular regions surrounded by the edge rib portions 83 along the edges 31a and 31b and the first rib portions 61c and 61d that intersect each other. The two partitioned regions 76c are defined as two substantially triangular regions surrounded by the edge rib portions 83 along the edges 31a and 31b and the first rib portions 61e and 61f that intersect each other. The two partitioned regions 76d are defined as two substantially triangular regions surrounded by the edge rib portions 83 along the edges 31a and 31b and the first rib portions 61g and 61h that intersect each other.

As described above, in power storage device 10, restraining plates 17, 18, 117, and 217 include a plurality of rib portions 38 and a plurality of thin portions 39 thinner than the plurality of rib portions 38 in the stacking direction. have. A plurality of thin portions 39 are defined by a plurality of rib portions 38 . Therefore, the plurality of thin portions 39 reduce the weight of the restraint plates 17 , 18 , 117 , 217 while the plurality of rib portions 38 ensure the rigidity of the restraint plates 17 , 18 , 117 , 217 .

Each first rib portion 41 , 61 extends on a straight line connecting the engaging portion 32 and the engaging portion 33 while being inclined with respect to the facing direction of the edges 31 a and 31 b. At least two of the plurality of first rib portions 41 and 61 cross each other. Furthermore, each of the plurality of second rib portions 42 and 62 extends in the facing direction of the edges 31a and 31b. Both ends of some of the plurality of second rib portions 42 and 62 are connected to the first rib portions 41 and 61 that cross each other. Therefore, the second rib portions 42 and 62 act as braces for the first rib portions 41 and 61 that cross each other. According to the arrangement of the rib portion 38 in this way, the force applied to the restraining plates 17, 18, 117, 217 from the connecting members 19 via the engaging portions 32, 33 causes the twisting of the restraining plates 17, 18, 117, 217. is improved without enlarging the area of the rib portion 38 . As a result, in the electric storage device 10, the weight of the constraining plates 17, 18, 117, and 217 can be reduced while ensuring the load on the electric storage modules 12 by the constraining plates 17, 18, 117, and 217 that constrain the electric storage modules 12. be done.

In the restraining plates 17, 18, 117, 217, both ends of each first rib portion 41, 61 are edge rib portions adjacent to any two of the plurality of engaging portions 32, 33, 34, 35. 43 and 83. Therefore, the plurality of first rib portions 41 and 61 function as braces for the edge rib portions 43 and 83 provided along the edges 31a and 31b. The second rib portions 42,62 extend in the partitioned areas 51,52,53,71,72,73,74,75 surrounded by the plurality of first rib portions 41,61. In the restraining plates 17, 18, 117, the rigidity of the restraining plates 17, 18, 117 against the load applied to the power storage module 12 is ensured, while the ratio of the area of the thin portion 39 to the area of the rib portion 38 when viewed from the stacking direction is can be enlarged.

In the restraining plates 17, 18, 117, 217, the plurality of first rib portions 41, 61 form a plurality of crossing portions 48, 68, respectively. The plurality of intersections 48 and 68 are arranged between the edges 31a and 31b in a direction intersecting the facing direction of the edges 31a and 31b when viewed from the stacking direction. According to this configuration, the weight of the restraint plates 17, 18, 117, 217 can be reduced while the rigidity of the centers of the restraint plates 17, 18, 117, 217 is ensured.

The constraining plates 17, 18, 117, and 217 have a rectangular shape with edges 31a and 31b as long sides when viewed from the stacking direction. Each engaging portion 32 is positioned on a straight line extending from one of the plurality of engaging portions 33 in the facing direction of the edges 31a and 31b. In this case, since the load is evenly applied to the restraining plates 17 , 18 , 117 , 217 in the long side direction, the restraining plates 17 , 18 , 117 , 217 are less likely to bend even if they receive force from the connecting member 19 . Therefore, even if the area of the rib portion 38 when viewed from the stacking direction is reduced, the rigidity of the restraining plate against the load applied to the power storage module 12 is ensured.

Each of the plurality of engaging portions 32, 33 has a through hole H1, H2 that passes through the restraining plates 17, 18, 117, 217 in the stacking direction and engages with one of the plurality of connecting members 19. , each of the plurality of thin portions 39 has an area larger than that of the through holes H1 and H2 when viewed from the stacking direction. In this case, segmentation of the thin portion 39 is suppressed, and easiness of molding of the restraining plates 17, 18, 117, 217 is ensured.

In the restraining plates 17 and 18, among the plurality of engagement portions 32 and 33, the engagement portions 32a, 32e, 33a, and 33e closest to the ends of the edges 31a and 31b have edge rib portions among the plurality of rib portions 38. 43 are connected. The first rib portion 41 is not connected to the engaging portions 32a, 32e, 33a, 33e. Since the restraining plates 17 and 18 have the edge rib portions 43, the rib portions 38 other than the edge rib portions 43 are connected to the engaging portions 32a, 32e, 33a and 33e closest to the ends of the edges 31a and 31b. Even if not, the load on the power storage module 12 can be ensured. Since the rib portions 38 other than the edge rib portion 43 are not connected to the engaging portions 32a, 32e, 33a, 33e, the weight of the restraining plates 17, 18 is further reduced.

In the constraining plates 17 and 18 , the density of the thin portions 39 in the partitioned regions 51 and 53 is higher than the density of the thin portions 39 in the partitioned region 52 . In order to appropriately bind the plurality of power storage modules 12, it is important to ensure the rigidity of the center of the binding plates 17 and 18. FIG. According to this configuration, the weight of the restraint plates 17 and 18 can be reduced while ensuring the rigidity of the centers of the restraint plates 17 and 18 .

In the restraint plates 17 and 18 , the density of the thin portions 39 within the partitioned region 54 is higher than the density of the thin portions 39 within the partitioned region 52 . Since the constraining plates 17 and 18 have edge rib portions 43, the rib portion 38 in the partitioned region 54 contributes more to the rigidity of the constraining plates 17 and 18 than the rib portion 38 in the partitioned region 52. low. Therefore, the weight of the restraint plates 17 and 18 can be further reduced while ensuring the rigidity of the restraint plates 17 and 18 against the load applied to the power storage module 12 .

In the partitioned areas 51, 52, 53 of the restraining plates 17, 18, the density of the thin portions 39 in the first portion in the partitioned area is higher than that in the partitioned area in the direction intersecting the facing direction of the edges 31a, 31b The density of the thinned portions 39 is greater in the second portion located closer to the center of the constraining plates 17, 18 than in the first portion within the region. According to this configuration, the rigidity of the restraint plates 17 and 18 is ensured, and further weight reduction of the restraint plates 17 and 18 is achieved.

In the constraining plates 17,18, the edge ribs 43 extend along the edges of the constraining plates 17,18. The corner rib portion 45 is inclined with respect to the edges 31a and 31c. The corner rib portion 45 extends so as to connect the edge rib portion 43 extending along the edge 31a and the edge rib portion 43 provided along the edge 31c. Therefore, even if force is applied from the connecting member 19, the restraint plates 17 and 18 are less likely to bend. Therefore, even if the area of the rib portion 38 when viewed from the stacking direction is reduced, the rigidity of the restraint plates 17 and 18 against the load applied to the power storage module 12 is ensured.

In the restraining plates 17, 18, the auxiliary rib portion 46 is inclined with respect to the facing direction outside the plurality of partitioned regions 51, 52, 53, and is edged on a straight line connecting the engaging portions 32, 33. It extends from the rib portion 43 to the first rib portion 41 . When the number of the first rib portions 41 is large, the rigidity of the restraint plates 17 and 18 is improved as compared to when the number of the first rib portions 41 is small. The shape of the thin portion 39 surrounded by the rib portion 38 becomes finer. It is difficult to mold the constraining plates 17 and 18 in which the shape of the thin portion 39 is too thin. If the auxiliary rib portion 46 is arranged, the rigidity of the restraint plates 17 and 18 against the load applied to the power storage module 12 is improved, the weight increase of the restraint plates 17 and 18 is suppressed, and the thin portion 39 is suppressed from being segmented. A balance is achieved.

Although the embodiments and modifications of the present invention have been described above, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

In this embodiment, a configuration in which each of the pair of restraining plates 17 and 18 has a plurality of rib portions 38 and a plurality of thin portions 39 has been described, but the present invention is not limited to this configuration. The plurality of rib portions 38 and the plurality of thin portions 39 may be provided only on one of the pair of restraint plates 17 and 18 .

The number of engaging portions 32, 33 on each of the restraining plates 17, 18, 117, 217 may be less than five, or may be six or more. The number of engaging portions 32, 33 on each of the restraining plates 17, 18, 117, 217 may be two or more.

In this embodiment, as described above, the shaft portion of the bolt 19a is inserted through each of the through holes H1 and H2, and the nut 19b is screwed onto the threaded end of the bolt 19a. At this time, the inner peripheries of the through holes H1 and H2 may be flat, or the inner peripheries of the through holes H1 and H2 may be provided with threads.

Although the configuration in which the bolt 19a is inserted through the through holes H1, H2 of the plurality of engaging portions 33a, 33b, 33c, 33d has been described in this embodiment, the configuration is not limited to this configuration. For example, instead of the through holes H1 and H2 in the engaging portions 33a, 33b, 33c and 33d of the restraining plate 18, holes that do not penetrate the engaging portions 33a, 33b, 33c and 33d may be provided in the main surface 18b. In this case, the threaded ends of the bolts 19a may be directly screwed into the threads provided on the inner circumferences of the holes of the engaging portions 33a, 33b, 33c, and 33d of the restraining plate . In the specification of the present application, the term “hole” also includes holes that do not penetrate through the restraining plates 17 and 18 .

DESCRIPTION OF SYMBOLS 10... Electricity storage apparatus 12... Electricity storage module 17, 18, 117, 217... Restriction plate 19... Connection member 31a, 31b, 31c, 31d... Edge, 32, 33, 34, 35... Engagement part, 38... Rib portion 39 Thin portion 41, 61 First rib portion 42, 62 Second rib portion 43, 83 Edge rib portion 45 Corner rib portion 46 Auxiliary rib portion 48, 68 Intersections, 51, 52, 53, 54, 71, 72, 73, 74, 75, 76... Partitioned areas, H1, H2... Through holes.

Claims (9)

a plurality of stacked power storage modules;
a pair of restraint plates sandwiching the plurality of power storage modules in the stacking direction;
a plurality of connecting members that connect the pair of constraining plates and apply a load to the plurality of power storage modules in the stacking direction via the pair of constraining plates;
Each of the pair of constraining plates has a first edge and a second edge facing each other and extending in a direction intersecting the opposing direction, and the plurality of connecting plates arranged along the first edge. a plurality of first engaging portions with which a part of the member respectively engages; and a plurality of second engaging portions arranged along the second edge and with which a portion of the plurality of connecting members respectively engages have
At least one of the pair of restraining plates has a plurality of rib portions and a plurality of thin portions defined by the plurality of rib portions and having a thickness in the stacking direction smaller than that of the plurality of rib portions. death,
The plurality of rib portions include an edge rib portion extending along the edge of the restraining plate, and an edge rib portion that is inclined with respect to the facing direction of the first edge and the second edge, and the first engaging portion. A plurality of extending first rib portions and a plurality of extending in the facing direction of the first edge and the second edge on a straight line connecting the mating portion and the second engaging portion a second rib portion;
Both ends of each of the first ribs are connected to the edge ribs,
at least two of the plurality of first rib portions extend in different directions and form crossing portions that cross each other;
The power storage device, wherein at least one of the plurality of second rib portions is connected to the first rib portions that cross each other at both ends. The plurality of first rib portions form a plurality of the intersection portions,
2. The power storage device according to claim 1, wherein said plurality of intersections are arranged between said first edge and said second edge in a direction intersecting said facing direction when viewed from said stacking direction. Each of the pair of restraining plates has a rectangular shape with the first edge and the second edge as long sides when viewed from the stacking direction,
3. The power storage device according to claim 1, wherein each of said first engaging portions is positioned on a straight line extending in said opposing direction from any one of said plurality of second engaging portions. each of the plurality of first engaging portions and second engaging portions has a hole that penetrates the restraining plate in the stacking direction and engages with one of the plurality of connecting members;
4. The power storage device according to claim 1, wherein each of said plurality of thin portions has an area larger than said hole when viewed in said stacking direction. The power storage device according to any one of claims 1 to 4, wherein the plurality of second rib portions are provided in a partitioned area surrounded and defined by the plurality of first rib portions. The plurality of second rib portions are provided in each of the plurality of partitioned regions,
The plurality of partitioned regions includes a first region and a second region positioned closer to the center of the restraint plate than the first region in a direction crossing the opposing direction when viewed from the stacking direction,
When viewed from the stacking direction, the value obtained by dividing the total area of the thin portions in the first region by the area of the first region is obtained by dividing the total area of the thin portions in the second region by the second area. The power storage device according to claim 5, wherein the power storage device is larger than the value divided by the area of the region . In the partitioned region when viewed from the stacking direction , the value obtained by dividing the total area of the thin portions in the first portion in the partitioned region by the area of the first portion is 7. The value obtained by dividing the total area of the thin portions in the second portion located closer to the center of the restraint plate than the first portion within by the area of the second portion. storage device. Each of the pair of restraint plates has a third edge and a fourth edge that intersect the first edge and the second edge and extend in directions along each other, and along the third edge a third engaging portion arranged and engaged by a portion of the plurality of connecting members; and a fourth engaging portion arranged along the fourth edge and engaged by a portion of the plurality of connecting members. has
The plurality of rib portions include edge rib portions extending along edges of the restraining plate and corner rib portions inclined with respect to the first edge and the third edge,
The corner rib portion extends to connect the edge rib portion extending along the first edge and the edge rib portion extending along the third edge. , the power storage device according to any one of claims 1 to 7. The plurality of rib portions are inclined with respect to the direction in which the first edge and the second edge are opposed, and are arranged on a straight line connecting the first engaging portion and the second engaging portion. The power storage device according to any one of claims 1 to 8, further comprising an auxiliary rib portion extending from the rib portion to the first rib portion.

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