JP7137778B2 - power storage device - Google Patents

Description

The present invention relates to a power storage device that includes a power storage element and a holding member that holds the power storage element.

A battery assembly used in a hybrid vehicle, an electric vehicle, or the like includes a battery stack, a restraining member, a battery monitoring board, a busbar module, and a fixing member (see Patent Document 1).

A battery stack is configured by stacking flat battery cells. A plurality of battery cells are electrically connected in series. Battery cells are, for example, nickel-hydrogen secondary batteries, lithium-ion secondary batteries, and organic radical batteries.

Hereinafter, the direction in which the battery cells are stacked is referred to as the stacking direction. A direction perpendicular to the stacking direction and along the long sides of the rectangular battery cells is referred to as a longitudinal direction. A direction perpendicular to the stacking direction and along the short sides of the rectangular battery cells is referred to as a vertical direction.

The exterior case of the battery cell has the form of a thin flat plate. An electrode laminate, an electrolyte, a terminal connection portion, a portion of the positive electrode terminal portion, and a portion of the negative electrode terminal portion are incorporated in the internal space of the exterior case.

The fixing member is a member for fixing the battery stack to a predetermined installation location. The fixing members are provided on both sides of the battery stack in the stacking direction. The fixing member is connected to the installation location, and both ends of the restraining member are fixed. The stationary member includes a first plate and a second plate. The first plate and the second plate are fixed in an overlapping state. The inner first plate is connected with the restraining member. A second plate located on the outside is fixed to the installation point. In this embodiment, the installation location is located below the assembled battery. Therefore, the lower part of the second plate is bent outward and a through hole is formed. It is fixed to the installation location by a bolt inserted through the through hole.

The restraining member restrains both side portions of the battery stack while pressing them in the stacking direction. The restraining member is a member extending in the stacking direction, and both ends thereof are bent inward. Therefore, the restraining member is formed to have a U-shaped cross section when viewed in the vertical direction. This end is fixed to a fixing member. Specifically, a hole is formed in the first plate, and a hole is also formed in the bent portion of the restraint member. A bolt is inserted through the hole to connect the restraint member and the first plate. Moreover, by tightening the bolt, the battery stack is pressed in the stacking direction. A total of four restraining members are provided on each side, with two restraining members spaced apart in the vertical direction.

In this type of assembled battery, the battery stack (battery cell) expands and contracts in the stacking direction as it is charged and discharged. Therefore, when the battery stack is extended, the fixing member is urged in the stacking direction. In this type of assembled battery, the battery stack (battery cell) may urge the fixing member in the stacking direction when subjected to vibration or the like.

Then, the fixing member fixed to the installation location via the bolt tends to tilt with the bolt side (installation location side) as a fulcrum. Along with this, the fixing member tends to move in the stacking direction more on the side opposite to the installation location (bolt) than on the installation location (bolt) side. Therefore, a force (force in the stacking direction) that is greater than that of a restraining member that is located closer to the installation location of the fixing member is applied to the restraining member that is located farther from the location where the fixing member is installed. Acts through connecting bolts.

As a result, in the conventional assembled battery, around the boundary between the restraint member and the fixed member located far from the installation location (specifically, around the ridgeline where the base end of the bent portion of the restraint member is located), the installation location A larger bending stress acts than around the boundary between the restraining member and the fixed member (specifically, around the ridge where the proximal end of the bent portion of the restraining member is positioned) near the edge.

That is, in the conventional assembled battery, local stress concentration occurs around the boundary between the fixing member and the restraining member, which are aligned with the storage elements in different directions and are connected to each other via the connecting portion.

JP-A-2017-4803

This embodiment suppresses the occurrence of local stress concentration around the boundary between the first frame and the second frame, which are aligned with the storage elements in different directions and are connected to each other via the connecting portion. An object of the present invention is to provide a power storage device capable of

The power storage device of this embodiment is
at least one storage element;
a holding member that holds the power storage element,
The holding member is
a first frame including a terminal portion aligned with the power storage element in a first direction and a mounting portion connected to one end of the terminal portion in a second direction orthogonal to the first direction;
a second frame including a body portion aligned with the storage element in a third direction perpendicular to the first direction and the second direction, and an extension portion extending from the body portion and extending along at least the outer surface of the terminal portion;
a joint connecting the first frame and the second frame in the first direction, the joint comprising two or more joints spaced apart in the second direction within the extension;
The attachment part includes an installation part fixed to the fixing surface to be attached,
The two or more connecting parts are arranged outward in a third direction from a first imaginary straight line passing through the fixed center of the installation part,
Among the two or more connecting portions, the connecting portions other than the connecting portion closest to the installation portion are arranged outward in the third direction from the connecting portion closest to the installation portion among the two or more connecting portions. be done.

According to the above configuration, when the power storage element urges the terminal end portion of the first frame in the first direction due to an external factor such as vibration or expansion of the power storage element during charging, the first frame uses the installation portion as a fulcrum. and try to fall outward. In this state, the amount of displacement in the first direction on the side opposite to the installation section side of the first frame in the second direction (the other end side of the terminal end) is the first direction on the installation section side of the first frame. proportionately more than the amount to be displaced to

However, since the two or more connecting portions are arranged outward in the third direction from the first imaginary straight line passing through the fixing center of the installation portion, the two or more connecting portions transmitting the force in the first direction Each is located near the boundary between the extension and the body. This reduces the bending moment at the boundary between the extending portion and the main body portion.

In addition, the connection portions other than the connection portion closest to the installation portion among the two or more connection portions are outward in the third direction from the connection portion closest to the installation portion among the two or more connection portions. Therefore, the bending moment due to the force acting around each connecting portion (the bending moment of the connecting portion between the main body portion and the extension portion) becomes numerically similar, and as a result, the bending stress also numerically approximates.

Specifically, as the first frame is biased by the storage element, the other end of the terminal portion tends to tilt more than the installation portion. , a larger force than the force acting on the connecting portion on the installation portion side. On the other hand, the distance from the connecting portion on the other end side of the terminal end to the boundary between the main body and the extending portion is greater than the distance from the connecting portion on the installation side to the boundary between the main body and the extending portion. is also short. Since the bending moment is obtained from the product of the force and the distance, the bending moment due to the force acting around each connecting portion (the bending moment of the connecting portion between the main body portion and the extension portion) approaches each other, resulting in , the bending stresses also approach each other. Therefore, local stress concentration around the boundary between the first frame and the second frame, which are aligned with the storage elements in different directions and are connected to each other via the connecting portion, is suppressed.

As one aspect of the present embodiment, the connection portion other than the connection portion closest to the installation portion among the two or more connection portions is the connection portion closest to the installation portion among the two or more connection portions. It may be arranged on an extension line of the second imaginary straight line connecting the fixed center of the part.

According to the above configuration, the second imaginary straight line is a straight line connecting the fixed center of the installation portion and the connecting portion arranged outside the first imaginary straight line passing through the fixed center. As it moves away from the fixed center, it is proportionally spaced from the first imaginary straight line passing through the fixed center. That is, the second imaginary straight line is inclined with respect to the first imaginary straight line, and proportionally approaches the boundary between the main body portion and the extension portion. The extension of the second imaginary straight line is also the same.

Therefore, the distance from the starting point of the extension line of the second imaginary straight line and each of the two or more connecting portions arranged on the extension line to the boundary between the main body portion and the extension portion is two or more in the second direction. It becomes the distance according to each position of the connection part. That is, the distance to the boundary between the main body and the extending portion is shorter for the connecting portion located farther from the fixed position in the second direction.

On the other hand, the force in the first direction acting along with the tilting of the first frame proportionally increases with the position farther from the fixed position in the second direction.

Therefore, in the power storage device having the above configuration, a balance between the force acting on each connecting portion in the first direction and the distance in the third direction from each connecting portion to the boundary between the main body portion and the extension portion can be obtained. The values of the bending moments at the locations corresponding to each joint at the boundary between the portion and the extension are approximated or equalized. As a result, the values of the bending stresses at the positions corresponding to the respective connecting portions are also brought close to each other or made uniform.

As another aspect of the present embodiment, the connection portion other than the connection portion on the other end side of the most terminal portion among the two or more connection portions is the other end side of the most terminal portion among the two or more connection portions. may be arranged on a second imaginary straight line that connects the connection portion at the position and the fixed center of the installation portion.

According to the above configuration, the second imaginary straight line is a straight line connecting the fixing center of the installation portion and the connecting portion arranged outside the first imaginary straight line passing through the fixing center. As it moves away from the fixed center, it is proportionally spaced from the first imaginary straight line passing through the fixed center. That is, the second imaginary straight line is inclined with respect to the first imaginary straight line, and proportionally approaches the boundary between the main body portion and the extension portion.

Therefore, the distance from each of the two or more connecting portions arranged on the second imaginary straight line to the boundary between the main body portion and the extension portion depends on the position of each of the two or more connecting portions in the second direction. distance. That is, the distance to the boundary between the main body and the extending portion is shorter for the connecting portion located farther from the fixed position in the second direction.

On the other hand, the force in the first direction acting along with the tilting of the first frame proportionally increases with the position farther from the fixed position in the second direction.

Therefore, in the power storage device having the above configuration, a balance between the force acting on each connecting portion in the first direction and the distance in the third direction from each connecting portion to the boundary between the main body portion and the extension portion can be obtained. The values of the bending moments at the locations corresponding to each joint at the boundary between the portion and the extension are approximated or equalized. As a result, the values of the bending stresses at the positions corresponding to the respective connecting portions are also brought close to each other or made uniform.

In these
a pair of first frames arranged on both sides of at least one storage element in the first direction;
a pair of second frames arranged on both sides of at least one storage element in a third direction;
Two or more connecting portions connecting one of the pair of second frames and the first frame, and connecting the other of the pair of second frames and the first frame The two or more connecting portions may be arranged symmetrically with respect to the center line extending in the second direction of the end portion of the first frame.

According to the above configuration, the urging force of the electric storage element acting on the end portion of the first frame acts equally or substantially equally on one second frame side and the other second frame side. As a result, the value of the bending moment (bending stress) around the boundary between the first frame and one of the second frames and the value of the bending moment (bending stress) around the boundary between the first frame and the other second frame is equalized. Therefore, concentration of stress around any connecting portion connecting the first frame and the second frame is suppressed.

in this case,
The mounting part is
a pair of legs spaced apart in a third direction, each leg extending in the second direction from one end of the terminal portion;
Each of the pair of legs may have a first end connected to one end of the terminal end and a second end opposite to the first end and including the installation portion. .

With this configuration, the pair of legs allows the terminal end to be positioned away from the fixing surface, so that the power storage elements aligned in the first direction with respect to the terminal end are also positioned away from the fixing surface. This improves the heat dissipation of the storage element.

Then, as described above, when the urging force of the electric storage element acts on the terminal end located away from the fixing surface due to the presence of the leg, tilting occurs according to the length of the leg. Variation in stress (bending moment) tends to occur in each part.

However, according to the present embodiment, as described above, the force acting on each connecting portion in the first direction and the distance in the third direction from each connecting portion in the first direction to the boundary between the main body portion and the extension portion As a result, the values of the bending moments at the positions corresponding to the respective connecting portions on the boundary between the main body portion and the extension portion are approximated or equalized. Therefore, even if the first frame has a leg with the terminal end positioned away from the fixing surface, the values of the bending stress at the positions corresponding to each of the two or more connecting parts approach or equalize. be done.

According to the present embodiment, local stress concentration around the boundary between the first frame and the second frame, which are aligned with the storage elements in different directions and are connected to each other via the connecting portion, is suppressed. An excellent effect of being able to

FIG. 1 is a perspective view of a power storage device according to this embodiment. FIG. 2 is an exploded perspective view of the power storage device. FIG. 3 is a front view of the power storage device. FIG. 4 is a perspective view of a first frame in the power storage device. FIG. 5 is a side view of a state in which the power storage device is fixed to a fixing surface to which it is attached. FIG. 6 is a partial front view of a state in which the power storage device is fixed to a fixing surface to which it is attached. FIG. 7 shows each position of the first frame in the second direction (Z-axis direction) and the amount by which each position in the second direction (Z-axis direction) is about to be displaced in the first direction (X-axis direction). 4 is a graph that schematically illustrates the relationship; FIG. 8 shows the relationship between each position in the second direction (Z-axis direction) of the first frame and the force in the first direction (X-axis direction) acting on each position in the second direction (Z-axis direction). Fig. 4 is a schematic graph; FIG. 9 is a side view of a state in which a power storage device according to another embodiment is fixed to a fixing surface to which it is attached.

An embodiment of the present invention will be described below with reference to the accompanying drawings. The name of each component (each component) of this embodiment is the one in this embodiment, and may differ from the name of each component (each component) in the background art.

As shown in FIGS. 1 to 3, the power storage device 1 includes at least one power storage element 2 and a holding member 4 that holds the at least one power storage element 2 . The power storage device 1 also includes an adjacent member 3 adjacent to the power storage element 2 . In addition, the power storage device 1 includes an insulator 5 arranged between at least one power storage element 2 and a holding member 4, different power storage elements 2, or a power storage element 2 and an external input/output terminal (not numbered). and a bus bar 6 (see FIGS. 1 and 2) that electrically connects the .

The power storage device 1 of this embodiment includes a plurality of power storage elements 2 . The plurality of power storage elements 2 are arranged in the first direction. In the following description, the direction in which the plurality of power storage elements 2 are arranged (first direction) is defined as the X-axis direction, and the direction (second direction) perpendicular to the X-axis direction is defined as the Z-axis direction. A direction (third direction) perpendicular to the direction is defined as a Y-axis direction. Along with this, in each drawing, orthogonal coordinates corresponding to the X-axis direction, the Y-axis direction, and the Z-axis direction (coordinates at which the X-axis, the Y-axis, and the Z-axis are orthogonal) are illustrated for convenience.

Each of the plurality of power storage elements 2 is a primary battery, a secondary battery, a capacitor, or the like. The storage element 2 of this embodiment is a chargeable/dischargeable non-aqueous electrolyte secondary battery. More specifically, the storage element 2 is a lithium ion secondary battery that utilizes electron transfer that occurs with the movement of lithium ions. The storage element 2 is a so-called square lithium ion secondary battery.

As shown in FIG. 2, each of the plurality of storage elements 2 includes an electrode body (not shown), a case 21 that houses the electrode body together with an electrolytic solution, and external terminals 22 that are at least partially exposed to the outside of the case 21. have

The case 21 has a case body 211 having an opening and a plate-like cover plate 216 that closes (closes) the opening of the case body 211 . The case main body 211 of this embodiment is in the shape of a square tube with a bottom, and the case 21 is in the shape of a flat rectangular parallelepiped. The case main body 211 includes a rectangular plate-like closing portion 212 and a cylindrical trunk portion (peripheral wall) 213 connected to the peripheral edge of the closing portion 212 . The trunk portion 213 has a flat rectangular tubular shape. The trunk portion 213 has a pair of long wall portions 214 extending from the long sides of the peripheral edge of the closing portion 212 and a pair of short wall portions 215 extending from the short sides of the peripheral edge of the closing portion 212 . By connecting the corresponding end portions of the pair of long wall portions 214 with the short wall portions 215 , the body portion 213 in the shape of a flat rectangular tube is formed. The cover plate 216 is a rectangular plate-like member that closes the opening of the case body 211 . A pair of external terminals 22 are arranged on the cover plate 216 .

In the power storage device 1 of this embodiment, the plurality of power storage elements 2 are arranged in the X-axis direction as described above. Each of the plurality of power storage elements 2 faces the long wall portion 214 of the case 21 (case body 211) in the X-axis direction.

The adjacent member 3 is arranged between two storage elements 2 arranged in the X-axis direction, or between the storage element 2 at the end in the X-axis direction and a member aligned in the X-axis direction with respect to the storage element 2 (example of this embodiment). , a portion of the holding member 4). The adjacent member 3 is made of an insulating member such as resin. Further, the adjacent member 3 forms a channel through which the fluid for adjusting the temperature of the storage element 2 can flow between the adjacent storage element 2 .

The holding member 4 is made of a conductive member such as metal. As shown in FIGS. 1 to 3, the holding member 4 surrounds the plurality of storage elements 2 and the plurality of adjacent members 3 to hold the plurality of storage elements 2 and the plurality of adjacent members 3 together. .

More specific description will be given. As shown in FIGS. 1 and 2, the holding member 4 includes a first frame 40 including a terminal portion 400 aligned with the storage element 2 in the X-axis direction and a mounting portion 401 connected to one end of the terminal portion 400 in the Z-axis direction. , a second frame 41 including a body portion 410 aligned with the storage element 2 in the Y-axis direction and an extension portion 411 extending from the body portion 410 and extending along at least the outer surface of the terminal portion 400, the first frame 40 and the second frame 41 in the X-axis direction, and two or more connection portions 42 are arranged in the extending portion 411 in the Z-axis direction at intervals.

In the holding member 4 according to this embodiment, a pair of first frames 40 are arranged on both sides of at least one storage element 2 in the X-axis direction, and a pair of second frames 41 are arranged on both sides of at least one storage element 2 in the Y-axis direction. A pair is arranged on both sides. That is, the holding member 4 includes a pair of first frames 40 arranged on both sides of the plurality of power storage elements 2 in the X-axis direction, and a pair of first frames 40 arranged on both sides of the plurality of power storage elements 2 in the Y-axis direction. It has a pair of second frames 41 connecting the ends of one frame 40 to each other.

In each of the pair of first frames 40, as shown in FIG. 4, the end portion 400 has a first surface facing the storage element 2 side in the X-axis direction and a side opposite to the storage element 2 side in the X-axis direction (outer side). ). Note that the terminal end portion 400 of the present embodiment is configured by stacking a plurality of members (two members in the present embodiment) in the X-axis direction. Along with this, the first surface of the terminal portion 400 is the outer surface of one member that is the most end in the X-axis direction, and the second surface of the terminal portion 400 is the outer surface of the other member that is the most end in the X-axis direction. It's the outside.

The end portion 400 has holes 402a and 402b penetrating in the X-axis direction at both ends thereof in the Y-axis direction. A bolt 420 (see FIG. 2) forming the connecting portion 42 is inserted through the holes 402a and 402b. In this embodiment, two holes 402a, 402b spaced apart in the Z-axis direction are provided at each of the ends of the terminal end 400 in the Y-axis direction.

At both ends of the terminal portion 400 in the Y-axis direction, of the two holes 402a and 402b spaced apart in the Z-axis direction, the hole 402a on the other end side of the terminal portion 400 in the Z-axis direction It is arranged outside in the Y-axis direction of the hole 402a on one end side of the terminal portion 400 in the direction. In this embodiment, the holes 402a and 402b at both ends of the termination portion 400 in the Y-axis direction are arranged symmetrically with respect to the center line CL extending in the Z-axis direction of the termination portion 400 as a reference.

The attachment portion 401 includes an installation portion 401a fixed to a fixing surface to be attached. In this embodiment, the mounting portion 401 includes a pair of leg portions 401b, 401b spaced apart in the Y-axis direction. Each of the pair of leg portions 401b, 401b extends from one end of the terminal portion 400 in the Z-axis direction. Each of the pair of leg portions 401b, 401b has a first end connected to one end of the terminal portion 400 and a second end opposite to the first end. A second end of the leg portion 401b includes a mounting portion 401a.

In the present embodiment, the end portion including the second end of the leg portion 401b is bent with respect to the first end side and constitutes an installation portion 401a having an installation surface facing outward in the Z-axis direction. The installation portion 401a is configured to be fixable to a fixing surface to which it is attached (for example, the chassis of an automobile or the outer surface of a mounting bracket fixed to the chassis). In this embodiment, the installation portion 401a is fixed to the fixing surface by a bolt having an axial center extending in the Z-axis direction.

Accordingly, the installation portion 401a is provided with a hole 403 through which the shaft portion of the bolt is inserted in the Z-axis direction. With such a configuration, the hole center of the hole 403 or the axis center of the bolt inserted through the hole 403 becomes the fixing center of the installation portion 401a. The fixing center of the installation portion 401a of one leg portion 401b overlaps with the extension line of the imaginary line connecting the two holes 402a and 402b in one end of the terminal portion 400 in the Y-axis direction when viewed from the X-axis direction. placed in position. Also, the fixing center of the installation portion 401a of the other leg portion 401b is an extension of a virtual line connecting two holes 402a and 402b in the other end portion of the terminal portion 400 in the Y-axis direction when viewed from the X-axis direction. placed in a position overlapping the

That is, the two holes 402a and 402b at one end of the terminal portion 400 in the Y-axis direction are the second holes that pass through the fixing center of the installation portion 401a of one leg portion 401b on one end side of the terminal portion 400. It is arranged outward in the Y-axis direction from the one imaginary straight line VL1. Also, the two holes 402a and 402b at the other end of the terminal portion 400 in the Y-axis direction are the second holes that pass through the fixed center of the installation portion 401a of the other leg portion 401b on the other end side of the terminal portion 400. It is arranged outward in the Y-axis direction from the one imaginary straight line VL1.

Of the two holes 402a and 402b at each end of the termination portion 400 in the Y-axis direction, the hole 402a other than the hole 402b closest to the installation portion 401a is It is arranged outward in the Y-axis direction from the hole 402b on the portion 401a side. In this embodiment, of the two holes 402a and 402b at each end of the termination portion 400 in the Y-axis direction, the hole 402a other than the hole 402b closest to the installation portion 401a A second hole connecting the hole 402b closest to the installation portion 401a of the two holes 402a and 402b at each end and the fixing center of the installation portion 401a of the leg 401b corresponding to the end with the hole 402b. It is arranged on the extension line EL of the virtual straight line VL2.

In this embodiment, the installation portion 401a protrudes outward in the X-axis direction from the terminal portion 400, and the fixed center is displaced from the terminal portion 400 in the X-axis direction. Along with this, the relationship between the first imaginary straight line VL1, the second imaginary straight line VL2, and the extension line EL proposed here (the reference for the placement of the holes 402a and 402b and the fixed center) is as viewed from the X-axis direction. This is the relationship (planar relationship ignoring the positional deviation in the X-axis direction).

Returning to FIG. 2 , each of the pair of first frames 40 is arranged so as to sandwich the plurality of power storage elements 2 with respective end portions 400 . Since the power storage device 1 of the present embodiment includes the adjacent members 3, the power storage elements 2 and the adjacent members 3 are alternately arranged in the X-axis direction. Along with this, the pair of first frames 40 are arranged so that the stack of the storage element 2 and the adjacent member 3 is sandwiched between the respective end portions 400 in the X-axis direction.

In addition, in the laminated body of the electric storage element 2 and the adjacent member 3, the adjacent member 3 is positioned at both ends in the X-axis direction. As a result, the end portion 400 of the first frame 40 is aligned with the storage element 2 with the adjacent member 3 interposed therebetween.

The pair of second frames 41 are arranged on both sides of the plurality of power storage elements 2 in the Y-axis direction, as described above. Each of the pair of second frames 41 includes a body portion 410 aligned with the storage element 2 in the Y-axis direction, and an extension portion 411 extending from the body portion 410 in the Y-axis direction and along at least the outer surface of the terminal portion 400 . include. In addition, each of the pair of second frames 41 extends in the Y-axis direction from a position different from the extending portion 411 in the main body portion 410 and extends along the outer surface of the storage element 2 (the closing portion 212 of the case 21). It has a portion 412 and a second extension portion 413 extending outward in the Z-axis direction from the first extension portion 412 . The second frame 41 of the present embodiment is formed by press-molding a metal plate, and the entirety (body portion 410, extension portion 411, first extension portion 412, second extension portion 413) is integrally molded. .

In each of the pair of second frames 41, the body portion 410 has a longitudinal side in the X-axis direction. The body portion 410 of this embodiment is formed in a ladder shape.

Each of the pair of second frames 41 has extensions 411 at both ends in the X-axis direction. That is, each of the pair of second frames 41 has a pair of extensions 411 .

The extending portion 411 is a portion that is connected to the end portion of the first frame 40 (the end portion of the terminal portion 400) in the Y-axis direction. That is, the extending portion 411 is a portion superimposed from the outside on the end portion of the first frame 40 in the Y-axis direction (the end portion of the terminal end portion 400). are connected in the X-axis direction.

Along with this, the extending portion 411 of the second frame 41 is formed in a plate shape that spreads in the Y-axis direction and the Z-axis direction and has a longitudinal direction in the Z-axis direction. The extending portion 411 has holes 414a and 414a at positions corresponding to the holes 402a and 402b provided at the ends of the first frame 40 (terminal portion 400) in the Y-axis direction (positions overlapping when viewed from the X-axis direction). 414b.

In the present embodiment, two holes 402a and 402b are provided at both ends of the first frame 40 (end portion 400) in the Y-axis direction, and are spaced apart in the Z-axis direction. The extending portion 411 is also provided with two holes 414a and 414b spaced apart in the Z-axis direction.

The two holes 414a and 414b of the extending portion 411 are also displaced in the Y-axis direction. That is, one of the two holes 414a and 414b of the extending portion 411 (the hole 414a located on the upper side when the Z-axis direction is taken as the vertical direction) In the Y-axis direction, the other hole 414b (the hole 414b located on the lower side when the Z-axis direction is taken as the vertical direction) is positioned outside.

In this embodiment, the connecting portion 42 includes a bolt 420 having a shaft-shaped male thread (not numbered) and a nut 421 having a female thread (screw hole) to be screwed into the male thread of the bolt 420. Consists of In the present embodiment, the nut 421 of the connecting portion 42 has its own female screw portion (screw hole) aligned with the holes 402a and 402b of the first frame 40 (terminal end portion 400), and the nut 421 of the terminal end portion 400 is mounted on the first end portion 400. It is fixed (welded in this embodiment) to the surface.

In the power storage device 1 of the present embodiment, the male threaded portion of the bolt 420 forming the connecting portion 42 is formed by the holes 414a and 414b of the extending portion 411 of the second frame 41 and the first frame 40 on which the extending portion 411 is overlapped. After being inserted through the holes 402a and 402b at the ends of the terminal portion 400, the nut 421 (female screw portion) is screwed. Thereby, the connecting portion 42 (the bolt 420 and the nut 421) connects the end portion 400 and the extending portion 411 in the X-axis direction. That is, each connecting portion 42 serves as a power point that transmits the force in the X-axis direction to the terminal end portion 400 and the extension portion 411 .

Since the bolts 420 are thus inserted through the holes 402a, 402b of the terminal end 400 and the holes 414a, 414b of the extension 411, the two connections in the extension 411 superimposed on the ends of the terminal end 400 are not connected. Portion 42 has an arrangement corresponding to the arrangement of holes 402 a and 402 b in terminal end 400 . That is, as shown in FIG. 5, the two connecting portions 42 are arranged outward in the Y-axis direction from the first imaginary straight line VL1 passing through the fixing center of the installation portion 401a.

In the present embodiment, of the two connecting portions 42 in the extending portion 411, the connecting portion 42 other than the connecting portion 42 closest to the installation portion 401a is the closest to the installation portion 401a. is arranged outward in the Y-axis direction from the connecting portion 42 located at . Further, in the present embodiment, of the two connecting portions 42 in the extending portion 411, the connecting portion 42 other than the connecting portion 42 closest to the installation portion 401a is It is arranged on the extension line EL of the second imaginary straight line VL2 connecting the connecting portion 42 on the 401a side and the fixing center of the installation portion 401a.

As described above, the installation portion 401a protrudes outward in the X-axis direction from the terminal end portion 400, and the fixed center of the installation portion 401a is displaced in the X-axis direction with respect to the terminal end portion 400 (connecting portion 42). is doing. Along with this, the relationship between the first virtual straight line VL1, the second virtual straight line VL2, and the extension line EL defined here (the reference for the arrangement of the connecting portion 42 and the fixed center) is also clear from FIG. , the relationship viewed from the X-axis direction (planar relationship ignoring positional deviation in the X-axis direction). In addition, "arranged on the extension line EL" here means that the center of the connecting portion 42 (in this embodiment, the axial center of the male screw portion of the bolt 420) is extended on the premise that it is viewed from the X-axis direction. In addition to being positioned on the line EL, the region where the force of the connecting portion 42 in the X-axis direction is transmitted to the extending portion 411 (in this embodiment, the region where the head of the bolt 420 and the nut exist) ) where the extension line EL passes through.

Here, the inclination of the second imaginary straight line VL2 (extended line EL) is displaced in the X-axis direction at each position (position in the Z-axis direction) of the first frame 40 that is about to be tilted with the biasing of the storage element 2. Of the two connecting portions 42, the connecting portion 42 closest to the installation portion 401a is arranged so as to have an inclination similar to or the same as the inclination of the inclination (see FIG. 7) representing the change in the amount of is preferred. That is, the force in the X-axis direction acting at each position (position in the Z-axis direction) of the first frame 40 where the inclination of the second imaginary straight line VL2 (extended line EL) tends to tilt along with the biasing of the power storage element 2 It is preferable that the connecting portion 42 closest to the installation portion 401a of the two connecting portions 42 is arranged so as to have an inclination similar to or the same as the inclination of the inclination representing the change in the (see FIG. 8). .

In this embodiment, two or more connecting portions 42 connecting the second frame 41 and the first frame 40 of the pair of second frames 41 and the other of the pair of second frames 41 The two or more connecting portions 42 connecting the two frames 41 and the first frame 40 are arranged symmetrically with respect to the center line CL extending in the Z-axis direction of the end portion 400 of the first frame 40 .

Returning to FIG. 2 , the insulator 5 has insulating properties and is arranged between the second frame 41 and the plurality of power storage elements 2 . The insulator 5 covers at least a region of the second frame 41 facing the plurality of power storage elements 2 . Specifically, in the insulator 5 of the present embodiment, the surface facing each storage element 2 in the main body portion 410 , the surface facing each storage element 2 in the first extension portion 412 , and the It covers at least the surface facing inward in the Y-axis direction. Thereby, the insulator 5 insulates between the second frame 41 and the plurality of power storage elements 2 .

The bus bar 6 is a plate-like member having conductivity such as metal. The bus bar 6 conducts between the external terminals 22 of the storage elements 2 or between the external terminals 22 of the storage elements 2 and external input/output terminals (not numbered). A plurality of busbars 6 are provided in the power storage device 1 (the number corresponds to the number of power storage elements 2 and the number of external input/output terminals). The plurality of busbars 6 of the present embodiment connect (make conductive) all of the plurality of storage elements 2 included in the storage device 1 in series.

As described above, the power storage device 1 of this embodiment includes at least one power storage element 2 and the holding member 4 that holds the power storage element 2. A first frame 40 including a mounting portion 401 connected to one end of a portion 400 and a terminal portion 400 in the Z-axis direction, a main body portion 410 aligned with the storage element 2 in the Y-axis direction, and at least a terminal end extending from the main body portion 410. a second frame 41 including an extending portion 411 along the outer surface of the portion 400; and a connecting portion 42 connecting the first frame 40 and the second frame 41 in the X-axis direction. two or more connecting portions 42 spaced apart in a direction, the mounting portion 401 including a mounting portion 401a fixed to a fixing surface to which it is mounted, and the two or more connecting portions 42 is arranged outward in the Y-axis direction from the first imaginary straight line VL1 passing through the fixed center of the installation portion 401a, and is located outside the two or more connection portions 42, except for the connection portion 42 closest to the installation portion 401a side. The connecting portion 42 is arranged outward in the Y-axis direction from the connecting portion 42 closest to the installation portion 401a among the two or more connecting portions 42 .

According to the above configuration, as shown in FIG. 6, when the storage element 2 urges the end portion 400 of the first frame 40 in the X-axis direction due to an external factor such as vibration or expansion of the storage element 2 during charging, Due to the action of the biasing force F, the first frame 40 tends to fall outward with the installation portion 401a as a fulcrum. Then, as shown in FIG. 7, the amount of displacement in the X-axis direction on the side opposite to the installation portion 401a side of the first frame 40 in the Z-axis direction (the other end side of the terminal end portion 400) is 40 is proportionately greater than the amount of displacement in the X-axis direction on the installation portion 401a side of 40 . Accordingly, as shown in FIG. 8, the force acting in the X-axis direction increases as the position is further away from the installation portion 401a serving as the tilting fulcrum. That is, the force in the X-axis direction increases proportionally from the installation portion 401a toward the other end of the termination portion 400. FIG.

However, according to the above configuration, as shown in FIG. 5, the two or more connecting portions 42 are arranged outside the first imaginary straight line VL1 passing through the fixed center of the installation portion 401a in the Y-axis direction. Each connecting portion 42 that transmits the force in the X-axis direction is located near the boundary E between the extending portion 411 and the main body portion 410 . As a result, the value of the bending moment at the boundary E between the extending portion 411 and the main body portion 410 is reduced.

In addition, the connection portions 42 other than the connection portion 42 closest to the installation portion 401a among the two or more connection portions 42 are the connection portions 42 closest to the installation portion 401a. , the values of the bending moment (the bending moment of the connecting portion between the main body portion 410 and the extending portion 411) due to the force acting around each connecting portion 42 approach each other, As a result, the bending stress values also approach each other.

Specifically, as the first frame 40 is biased by the power storage element 2 , the other end of the terminal portion 400 tends to tilt more than the one end. A force larger than the force acting on the other connecting portion 42 on the side of the installation portion 401a acts on the connecting portion 42 (see FIG. 8). On the other hand, the distance from one connecting portion 42 on the other end side of the terminal end portion 400 to the boundary E between the main body portion 410 and the extension portion 411 is the distance from the other connecting portion 42 on the installation portion 401a side to the main body portion. It is shorter than the distance to boundary E between 410 and extension 411 (see FIG. 5). Since the bending moment is obtained from the product of the force and the distance, the bending moment due to the force acting around each connecting portion 42 (the bending moment at the connection portion between the main body portion 410 and the extension portion 411) can be numerically calculated as follows: As a result, the bending stress also approaches numerically. Therefore, local stress concentration around the boundary between the first frame 40 and the second frame 41, which are aligned with the storage element 2 in different directions and are connected to each other via the connecting portion 42, is suppressed. be.

In particular, in the present embodiment, the connection portions 42 other than the connection portion 42 closest to the installation portion 401a among the two or more connection portions 42 are located closest to the installation portion 401a among the two or more connection portions 42. It is arranged on an extension line EL of a second imaginary straight line VL2 connecting a connecting portion 42 and the fixed center of the installation portion 401a.

According to the above configuration, the second virtual straight line VL2 is a straight line that connects the fixed center of the installation portion 401a and the connecting portion 42 arranged outside the first virtual straight line VL1 that passes through the fixed center. As shown in FIG. 5 , as it moves away from the fixed center of the installation portion 401a in the Z-axis direction, it separates proportionally from the first imaginary straight line VL1 passing through the fixed center of the installation portion 401a. That is, the second virtual straight line VL2 is inclined with respect to the first virtual straight line VL1 and approaches the boundary E between the main body portion 410 and the extension portion 411 proportionally. The same applies to the extension line EL of the second imaginary straight line VL2.

Therefore, the distance from the starting point of the extension line EL of the second imaginary straight line VL2 and each of the two or more connecting portions 42 arranged on the extension line EL to the boundary E between the main body portion 410 and the extension portion 411 is The distances correspond to the respective positions of the two or more connecting portions 42 in the Z-axis direction. That is, the distance to the boundary E between the main body portion 410 and the extending portion 411 is proportionally shorter for the connecting portion 42 located farther from the fixed position of the installation portion 401a in the Z-axis direction.

On the other hand, as shown in FIG. 8, the force in the X-axis direction acting along with the tilting of the first frame 40 proportionally increases with the position farther from the fixed position of the installation portion 401a in the Z-axis direction.

Therefore, in the power storage device 1 configured as described above, a balance between the force in the X-axis direction acting on each connecting portion 42 and the distance from each connecting portion 42 to the boundary E between the main body portion 410 and the extension portion 411 can be obtained. As a result, the bending moments at the positions corresponding to the connecting portions 42 on the boundary E between the main body portion 410 and the extending portion 411 are made closer or equalized. As a result, the bending stresses at the positions corresponding to the connecting portions 42 are made closer or uniform.

In this embodiment, a pair of first frames 40 are arranged on both sides of at least one storage element 2 in the X-axis direction, and a pair of second frames 41 are arranged on both sides of at least one storage element 2 in the Y-axis direction. Two or more connecting portions 42 arranged to connect one second frame 41 of the pair of second frames 41 and the first frame 40, and the other second frame of the pair of second frames 41 The two or more connecting portions 42 connecting 41 and the first frame 40 are arranged symmetrically with respect to the center line CL extending in the Z-axis direction of the terminal end portion 400 of the first frame 40 .

According to the above configuration, the biasing force F of the power storage element 2 acting on the end portion 400 of the first frame 40 acts equally or substantially equally on one second frame 41 side and the other second frame 41 side. As a result, the bending moment (bending stress) around the boundary E between the first frame 40 and one of the second frames 41 and the bending moment (bending stress) around the boundary E between the first frame 40 and the other second frame 41 ) are equalized. Therefore, concentration of stress around any connecting portion 42 connecting the first frame 40 and the second frame 41 is suppressed.

In addition, in the present embodiment, the mounting portion 401 is a pair of leg portions 401b that are spaced apart in the Y-axis direction and each extends in the Z-axis direction from one end of the terminal portion 400. and each of the pair of leg portions 401b has a first end connected to one end of the terminal portion 400 and a second end opposite to the first end and including the installation portion 401a. have

With this configuration, the terminal end portion 400 is arranged at a position away from the fixing surface in the Z-axis direction by the pair of leg portions 401b. They are arranged at separate positions in the axial direction. Thereby, the heat dissipation property of the electric storage element 2 is improved.

Then, as described above, when the urging force F by the power storage element 2 acts on the terminal end portion 400 located away from the fixed surface due to the presence of the leg portion 401b, tilting according to the length of the leg occurs. Variation in stress (bending moment) tends to occur at each of the one or more connecting portions 42 .

However, according to this embodiment, as described above, the balance between the force acting on each connecting portion 42 in the X-axis direction and the distance from each connecting portion 42 to the boundary E between the main body portion 410 and the extension portion 411 is As a result, the bending moments at the positions corresponding to the respective connecting portions 42 on the boundary E between the main body portion 410 and the extension portion 411 become closer or uniform. Therefore, even if the first frame 40 has a leg portion 401b that disposes the terminal end portion 400 away from the fixing surface, the bending stresses at the positions corresponding to each of the two or more connecting portions 42 approach or homogenized.

Therefore, according to the power storage device 1 according to the present embodiment, around the boundary E between the first frame 40 and the second frame 41, which are aligned with the power storage elements 2 in different directions and are connected to each other via the connecting portion 42, On the other hand, an excellent effect can be obtained in that it is possible to suppress the occurrence of local stress concentration.

It should be noted that the power storage device of the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention. For example, the configuration of one embodiment can be added to the configuration of another embodiment, and part of the configuration of one embodiment can be replaced with the configuration of another embodiment. Furthermore, some of the configurations of certain embodiments can be deleted.

In the power storage device 1 of the above embodiment, the connecting portion 42 that connects the first frame 40 and the second frame 41 is configured by the bolt 420 and the nut 421, but it is not limited to this. For example, the connecting portion 42 may be a fastening member such as a rivet. Also, the connection portion 42 may be a welded portion in which the end portion 400 and the extension portion 411 are welded together. In these cases, when the connecting portion 42 is a fastening member such as a rivet, the area where the force in the X-axis direction is transmitted is the area where the head portion of the fastening member or the caulking (deformation expansion portion) exists. , when the connecting portion 42 is a welded portion, the terminal portion 400 and the extension portion 411 are physically connected to form a welded region. Therefore, when the connecting portion 42 is arranged on the extension line EL of the second imaginary straight line VL2, the extension line EL may pass through the area where the head of the fastening member exists and the welding area.

In the above embodiment, the nut 421 forming the connecting portion 42 is welded to the first frame 40, but the present invention is not limited to this. For example, the nut 421 forming the connecting portion 42 may be independent from the terminal end portion 400 of the first frame 40 .

Although the first frame 40 (end portion 400) of the above embodiment has a laminated structure in which a plurality of members are stacked, the structure is not limited to this. The first frame 40 (end portion 400) may be a single layer structure. That is, the first frame 40 may be integrally molded as a whole like the second frame 41 .

In the above embodiment, two connecting portions 42 are provided at the ends of the terminal end portion 400 in the Y-axis direction, but the present invention is not limited to this. For example, three or more connecting portions 42 may be provided for the end portion of the termination portion 400 in the Y-axis direction. Also in this case, the three or more connecting portions 42 are arranged outside the first imaginary straight line VL1 in the Y-axis direction, and the connecting portion closest to the installation portion 401a among the two or more connecting portions 42 Of course, the connecting portions 42 other than 42 are arranged outward in the Y-axis direction from the connecting portion 42 closest to the installation portion 401a among the two or more connecting portions 42 .

In the above embodiment, it is arranged on the extension line EL of the second imaginary straight line VL2 that connects the connection portion 42 closest to the installation portion 401a among the two or more connection portions 42 and the fixing center of the installation portion 401a. , but not limited to. For example, as shown in FIG. 9 , the connection portion 42 other than the connection portion 42 closest to the other end of the terminal portion 400 of the two or more connection portions 42 is the terminal end of the two or more connection portions 42 . It may be arranged on a second imaginary straight line VL2 that connects the connecting portion 42 on the other end side of the portion 400 and the fixed center of the installation portion 401a. By doing so, the same actions and effects as those of the above-described embodiment can be obtained.

Specifically, the second imaginary straight line VL2 is a straight line that connects the fixed center of the installation portion 401a and the connecting portion 42 arranged outside the first imaginary straight line VL1 passing through the fixed center. As it moves away from the fixed center of the installation portion 401a in the axial direction, it is proportionally separated from the first imaginary straight line VL1 passing through the fixed center of the installation portion 401a. That is, the second virtual straight line VL2 is inclined with respect to the first virtual straight line VL1 and approaches the boundary E between the main body portion 410 and the extension portion 411 proportionally.

Therefore, the distance from each of the two or more connecting portions 42 arranged on the second imaginary straight line VL2 to the boundary E between the main body portion 410 and the extension portion 411 is the distance between the two or more connecting portions 42 in the Z-axis direction. is the distance corresponding to each position of That is, the distance to the boundary E between the main body portion 410 and the extending portion 411 is proportionally shorter for the connecting portion 42 located farther from the fixed position of the installation portion 401a in the Z-axis direction.

On the other hand, the force in the X-axis direction acting along with the tilting of the first frame 40 proportionally increases as the position in the Z-axis direction is farther from the fixing position of the installation portion 401a.

Therefore, in the power storage device configured as described above, the force in the X-axis direction acting on each connecting portion 42 and the distance in the Y-axis direction from each connecting portion 42 to the boundary E between the main body portion 410 and the extension portion 411 are balanced. As a result, the bending moments at the positions corresponding to the connecting portions 42 on the boundary between the main body portion 410 and the extension portion 411 become closer or uniform. As a result, the bending stresses at the positions corresponding to the connecting portions 42 are made closer or uniform.

In this case, the inclination of the second virtual straight line VL2 approximates or has the same inclination as the inclination representing the change in the amount of displacement in the X-axis direction at each position (position in the Z-axis direction) of the first frame 40. Among the two or more connecting portions 42, it is preferable that the connecting portion 42 closest to the other end of the terminal portion 400 is arranged. That is, the inclination of the second imaginary straight line VL2 represents the change in the force in the X-axis direction acting at each position (each position in the Z-axis direction) of the first frame 40 that is about to tilt due to the biasing of the power storage element 2. Of the two or more connecting portions 42, the connecting portion 42 closest to the other end of the terminal portion 400 is preferably arranged so as to have an inclination similar to or the same as the inclination of the inclination. Also in this case, the relationship between the first imaginary straight line VL1 and the second imaginary straight line VL2 (the reference for the placement of the connecting portion 42 and the fixed center of the installation portion 401a) is also as clear from FIG. This is the relationship viewed from the X-axis direction (planar relationship ignoring positional deviation in the X-axis direction).

In the above embodiment, the connecting portion 42 is arranged on the second imaginary straight line VL2 or on the extension line EL, but it is not limited to this. For example, the two or more connecting parts 42 may be arranged at positions off the second imaginary straight line VL2 or the extension line EL. However, among the two or more connecting portions 42, the connecting portion 42 other than the connecting portion 42 closest to the installation portion 401a is closer to the installation portion 401a than the connecting portion 42 closest to the installation portion 401a. are arranged outward in the Y-axis direction.

Although the power storage device 1 includes a plurality of power storage elements 2 in the above embodiment, the present invention is not limited to this. For example, the power storage device 1 may include one power storage element 2 . That is, the power storage device 1 may include at least one power storage element 2 .

Reference Signs List 1 power storage device 2 power storage element 3 adjacent member 4 holding member 5 insulator 6 bus bar 21 case 22 external terminal 40 first frame 41 second frame 42 ... Connecting part 211 ... Case main body 212 ... Closing part 213 ... Body part 214 ... Long wall part 215 ... Short wall part 216 ... Lid plate 400 ... Terminal part 401 ... Mounting part 401a ... Installation part 401b... Legs 402a, 402b... Hole 403... Hole 410... Body part 411... Extension part 412... First extension part 413... Second extension part 414a, 414b... Hole 420... Bolt, 421... Nut, CL... Center line, EL... Extension line, VL1... First imaginary straight line, VL2... Second imaginary straight line, E... Boundary

Claims (5)

multiple in a row and a storage element of
Saidplurala holding member that holds the power storage element,
The holding member is
The direction in which the plurality of storage elements are arranged said in the first directionpluralA terminal portion aligned with the storage element and perpendicular to the first directionPredetermineda first frame including a mounting portion connected to one end of said terminal portion of the direction;
a second direction that is the predetermined direction in which the terminal end portion and the mounting portion are aligned; andsaid first directioneach ofin a third direction orthogonal toplurala second frame including a main body arranged with the power storage element and an extension extending from the main body along at least the outer surface of the terminal end;
a connecting portion connecting the first frame and the second frame in the first direction, the connecting portion being spaced apart in the second direction within the extending portion; ,
The mounting portion includes a mounting portion fixed to a fixing surface to be mounted,
The two or more connecting portions are arranged outward in the third direction from a first imaginary straight line passing through the fixed center of the installation portion,
Among the two or more connecting portions, the connecting portion other than the connecting portion closest to the installing portion is closer to the installing portion than the connecting portion closest to the installing portion. positioned outward in the direction of
storage device. Among the two or more connecting portions, the connecting portion other than the connecting portion closest to the installing portion is located between the connecting portion closest to the installing portion among the two or more connecting portions and the installing portion. placed on the extension of the second imaginary straight line connecting the fixed center,
The power storage device according to claim 1 . A connecting portion other than the connecting portion closest to the other end of the terminal portion among the two or more connecting portions is the connecting portion closest to the other end of the terminal portion among the two or more connecting portions. arranged on a second imaginary straight line connecting the connecting portion and the fixed center of the installation portion;
The power storage device according to claim 1 . a pair of the first frames arranged on both sides of the plurality of power storage elements in the first direction;
a pair of the second frames arranged on both sides of the plurality of power storage elements in the third direction;
The two or more connecting portions that connect one second frame of the pair of second frames and the first frame, and the other second frame of the pair of second frames and the first frame. The two or more connecting portions connecting the frames are arranged symmetrically with respect to a center line extending in the second direction of the end portion of the first frame,
The power storage device according to any one of claims 1 to 3. The mounting portion is
a pair of legs spaced apart in the third direction, each leg extending in the second direction from one end of the terminal portion;
Each of the pair of leg portions has a first end connected to the one end of the terminal portion and a second end opposite to the first end and including the installation portion. ,
The power storage device according to claim 4.

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