JP7484126B2 - Power storage device - Google Patents

Description

The present invention relates to an electricity storage device.

Conventionally, in an energy storage device, multiple bus bars are connected to multiple energy storage elements (single cells) arranged in a predetermined direction via bus bar holding members (multiple connection units) (see, for example, Patent Document 1). A power cable (power line) is placed on the bus bar holding member and electrically connected to one of the energy storage elements.

JP 2011-181453 A

Here, when arranging the power cable inside the multiple bus bars, it is necessary to make the connection structure between one end of the power cable and the energy storage element compact due to space constraints. However, if a dedicated connection structure is adopted to make it compact, manufacturing costs will increase.

It has also been considered to bend the power cable sharply to fit it into a small space, but because the power cable is thicker and harder to bend than, for example, a detection wire used to detect voltage, bending the power cable sharply would increase the load on the power cable.

Therefore, the object of the present invention is to provide an energy storage device that can stably hold the end of a power cable while suppressing the load on the power cable.

In order to achieve the above object, an energy storage device according to one aspect of the present invention includes a plurality of energy storage elements arranged along a predetermined direction, a plurality of bus bars electrically connected to the plurality of energy storage elements, a bus bar holding member arranged on the plurality of energy storage elements and holding the plurality of bus bars, and a power cable electrically connected to one of the plurality of energy storage elements, the bus bar holding portion being arranged inwardly of the plurality of bus bars and having a cable path portion in which the power cable is arranged in a posture along the predetermined direction, and the cable path portion having a guide portion that guides one end of the power cable connected to the one energy storage element into a posture inclined with respect to the predetermined direction.

According to this, by tilting one end of the power cable relative to the arrangement direction (predetermined direction) of the multiple storage elements, the amount of bending of the power cable can be reduced while ensuring installation space for the connection structure compared to when it is perpendicular. In other words, it becomes possible to adopt a general-purpose round terminal, for example. In this way, the busbar holding portion is provided with a guide portion that guides one end of the power cable into a position that is tilted relative to the arrangement direction, so that it is possible to stably hold the end of the power cable while reducing the burden on the power cable.

Furthermore, each of the multiple storage elements may have a gas exhaust valve, and the gas exhaust valves may be arranged in a position facing the same direction, and the cable path portion may be disposed between the multiple bus bars and each of the gas exhaust valves of the multiple storage elements.

With this, since the cable path section is disposed between the multiple bus bars and the gas exhaust valves of the multiple energy storage elements, the power cable in the cable path section is also disposed in a position away from the gas exhaust valve. Therefore, it is possible to make it difficult for the power cable to be exposed to the gas exhausted from the gas exhaust valve.

The guide portion may also be formed in a flat shape.

With this, the guide portion is flat, so one end of the power cable can be guided in a straight line. This further reduces the strain on the power cable.

The acute angle between the guide portion and the specified direction may be less than 45 degrees.

With this, the acute angle between the guide portion and the specified direction is less than 45 degrees, so one end of the power cable guided by the guide portion is also positioned at approximately the same angle with respect to the specified direction. This makes it possible to reduce the moment applied to the connection between one end of the power cable and the storage element when the other end of the power cable is pulled. This makes it possible to stabilize the connection between one end of the power cable and the storage element.

The guide portion may also be disposed between one of the bus bars and one of the energy storage elements.

With this, the guide portion is disposed between one of the bus bars and one of the storage elements, so that even if one end of the power cable becomes detached from the storage element, the guide portion acts as a barrier and prevents interference with the bus bar or other storage elements.

The power storage device of the present invention can stably hold the end of the power cable while reducing the load on the power cable.

1 is a perspective view showing an external appearance of a power storage device according to an embodiment; FIG. 2 is an exploded perspective view illustrating components of the electricity storage unit according to the embodiment. FIG. 2 is an exploded perspective view showing a schematic configuration of an exhaust portion and a bus bar frame according to the embodiment. FIG. 2 is a top view showing a schematic configuration of a bus bar frame according to an embodiment. 5 is an explanatory diagram showing the positional relationship between a beam portion and an energy storage element according to the embodiment. FIG. 5 is a cross-sectional view showing the positional relationship between a beam portion and an exhaust portion in the embodiment. FIG. FIG. 4 is a top view showing a schematic configuration of a guide portion according to the embodiment. 2 is a perspective view showing a schematic configuration of a detection line holding section according to an embodiment; FIG. 4 is a cross-sectional view showing a schematic configuration of a detection line holding section in the embodiment. FIG. 11 is a cross-sectional view showing a schematic configuration of a detection line holding section according to Modification 1. FIG. FIG. 11 is a perspective view of a bus bar frame according to a second modified example, showing the vicinity of a guide portion.

The following describes an energy storage device according to an embodiment of the present invention (including its modified examples) with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement positions, and connection forms shown in the following embodiments are merely examples and are not intended to limit the present invention. Also, the dimensions in each figure are not strictly shown.

In the following description and drawings, the X-axis direction is defined as the direction in which a pair of electrode terminals (positive and negative) in one storage element are aligned, the direction in which the short sides of the storage element's container face each other, or the direction in which the long sides of the storage unit's exterior body face each other. The Y-axis direction is defined as the direction in which the storage elements are aligned, the direction in which the long sides of the storage element's container face each other, the direction in which the short sides of the storage unit's exterior body face each other, the direction in which the storage unit and the board unit face each other, or the direction in which the board holder, board, and cover of the board unit face each other. The Z-axis direction is defined as the direction in which the storage unit's exterior body support and exterior body lid are aligned, the direction in which the storage element and the bus bar are aligned, the direction in which the storage element's container body and lid are aligned, or the up-down direction. The X-axis direction, Y-axis direction, and Z-axis direction are mutually intersecting (orthogonal in this embodiment). Note that, depending on the mode of use, the Z-axis direction may not be the up-down direction, but for convenience of explanation, the Z-axis direction is described below as the up-down direction.

In the following description, for example, the positive X-axis direction refers to the direction of the X-axis arrow, and the negative X-axis direction refers to the opposite direction to the positive X-axis direction. The same applies to the Y-axis and Z-axis directions. In the following, the Y-axis direction may also be called the first direction, the X-axis direction may also be called the second direction, and the Z-axis direction may also be called the third direction. Furthermore, expressions indicating relative directions or attitudes, such as parallel and perpendicular, may also include cases where the directions or attitudes are not strictly those. For example, saying that two directions are perpendicular does not only mean that the two directions are completely perpendicular, but also means that they are substantially perpendicular, that is, there is a difference of, for example, about a few percent.

(Embodiment)
[1. Description of the configuration of the power storage device]
First, the configuration of an energy storage device 1 according to the present embodiment will be described. Fig. 1 is a perspective view showing the appearance of an energy storage device 1 according to the embodiment. Fig. 2 is an exploded perspective view showing each component when an energy storage unit 10 according to the embodiment is disassembled.

The power storage device 1 is a device that can charge electricity from an external source and discharge electricity to the outside, and in this embodiment, has a substantially rectangular parallelepiped shape. For example, the power storage device 1 is used for power storage or power source applications. Specifically, the power storage device 1 is used as a stationary battery for home use or for power generation. The power storage device 1 can also be used as a battery for driving or starting the engine of a moving object such as an automobile, motorcycle, watercraft, ship, snowmobile, agricultural machinery, construction machinery, or railroad vehicle for electric railway. Examples of the above-mentioned automobiles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and gasoline-powered automobiles. Examples of the above-mentioned railroad vehicles for electric railways include electric trains, monorails, and linear motor cars.

As shown in these figures, the energy storage device 1 includes an energy storage unit 10 and a substrate unit 20 attached to the energy storage unit 10. The energy storage unit 10 is a battery module (battery assembly) having a generally rectangular parallelepiped shape that is elongated in the Y-axis direction. Specifically, the energy storage unit 10 includes a plurality of energy storage elements 11, a bus bar frame 12, an exhaust section 50, a plurality of bus bars 13, and an exterior body 18 that includes an exterior body main body 14, an exterior body support body 15, and an exterior body cover body 17 that accommodates these. A cable 30 is connected to the energy storage unit 10. The energy storage unit 10 may include restraining members (end plates, side plates, etc.) that restrain the plurality of energy storage elements 11.

The storage element 11 is a secondary battery (single cell) that can charge and discharge electricity, and more specifically, is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The storage element 11 has a flat rectangular parallelepiped shape (square shape), and in this embodiment, 16 storage elements 11 are arranged in the Y-axis direction. The shape, arrangement position, number, etc. of the storage elements 11 are not particularly limited. The storage element 11 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery other than a non-aqueous electrolyte secondary battery, or may be a capacitor. The storage element 11 may not be a secondary battery, but may be a primary battery that can use stored electricity without the user having to charge it. Furthermore, the storage element 11 may be a battery using a solid electrolyte. The storage element 11 may also be a laminated storage element.

Specifically, the energy storage element 11 includes a metal container 11a that forms a main body, and the lid of the container 11a is provided with a positive electrode terminal 11b and a negative electrode terminal 11c, which are metal electrode terminals. That is, the positive electrode terminal 11b and the negative electrode terminal 11c are provided on the upper surface of the main body. The lid of the container 11a is provided with a gas exhaust valve 111 (see FIG. 4) between the positive electrode terminal 11b and the negative electrode terminal 11c, which exhausts gas when the pressure inside the container 11a rises to release the pressure. The multiple energy storage elements 11 are arranged in a position in which each gas exhaust valve 111 faces the same direction (the positive direction of the Z axis). In addition, a flat spacer 11d having thermal insulation properties is arranged between adjacent energy storage elements 11. The lid of the container 11a may be provided with a liquid injection section for injecting an electrolyte. Inside the container 11a, electrodes (also called storage elements or power generation elements) and current collectors (positive and negative current collectors) are arranged, and an electrolyte (non-aqueous electrolyte) is enclosed, but a detailed description is omitted.

Here, the positive electrode terminal 11b and the negative electrode terminal 11c are arranged to protrude upward (in the positive direction of the Z axis) from the lid of the container 11a. The outermost positive electrode terminal 11b and the negative electrode terminal 11c of the multiple storage elements 11 are connected to the cable 30, so that the storage device 1 can charge with electricity from the outside and discharge electricity to the outside.

The cable 30 is an electric wire (also called a power cable, power cable, power line, or power line) through which current (also called a charge/discharge current or main current) flows for charging and discharging the energy storage device 1 (energy storage elements 11), and has a positive power cable 31 on the positive side and a negative power cable 32 on the negative side. In other words, the positive power cable 31 of the cable 30 is connected to the positive terminal 11b of the energy storage element 11 at the end in the positive direction of the Y axis among the multiple energy storage elements 11, and the negative power cable 32 of the cable 30 is connected to the negative terminal 11c of the energy storage element 11 at the end in the negative direction of the Y axis.

The busbar frame 12 is a flat rectangular member that can electrically insulate the busbars 13 from other members and can regulate the position of the busbars 13. The busbar frame 12 is formed of an insulating material similar to that of the substrate accommodating section 100 of the substrate unit 20 described later, such as polycarbonate (PC), polypropylene (PP), or polyethylene (PE). Specifically, the busbar frame 12 is placed above the multiple energy storage elements 11 and positioned relative to the multiple energy storage elements 11. In addition, multiple busbars 13 are placed and positioned on the busbar frame 12. As a result, each busbar 13 is positioned relative to the multiple energy storage elements 11 and joined to the positive terminals 11b and negative terminals 11c of the multiple energy storage elements 11. The busbar frame 12 also has a function of reinforcing the exterior body main body 14 as an inner lid of the exterior body 18. Details of the busbar frame 12 will be described later.

The exhaust section 50 is disposed on the bus bar frame 12 and constitutes an exhaust path 59 (see FIG. 6) for the gas exhausted from the gas exhaust valve 111 of each storage element 11. One end of the exhaust section 50 in the positive Y-axis direction is an exhaust port 51 through which gas is exhausted, and protrudes from one end of the exterior body 18 in the positive Y-axis direction. Details of the exhaust section 50 will be described later.

Each bus bar 13 is a rectangular plate-like member arranged on the multiple storage elements 11 (on the bus bar frame 12) and electrically connects the electrode terminals of the multiple storage elements 11. The bus bar 13 is formed of a metal such as aluminum, aluminum alloy, copper, copper alloy, stainless steel, etc. In this embodiment, the bus bar 13 connects the positive terminal 11b and the negative terminal 11c of the adjacent storage elements 11 to connect the 16 storage elements 11 in series. The multiple bus bars 13 are divided into a first bus bar group 131 arranged along the Y axis direction on the positive side of the X axis (one side), and a second bus bar group 132 arranged along the Y axis direction on the negative side of the X axis (the other side). Note that the connection of the storage elements 11 is not limited to the above, and any combination of series connection and parallel connection may be used.

In addition, a detection line 13a is connected to the bus bar 13 or the electrode terminal of the storage element 11. The detection line 13a is a cable for detecting the state of each storage element 11. The detection line 13a is an electric wire (also called a communication cable, control cable, communication line, or control line) for measuring the voltage or temperature of the storage element 11, or for balancing the voltage between the storage elements 11. Note that a thermistor (not shown) for measuring the temperature of the storage element 11 is arranged on the bus bar 13 or the electrode terminal of the storage element 11, but the description is omitted. In addition, a connector 13b is connected to the end of the detection line 13a in the negative Y-axis direction. The connector 13b is a connector connected to the board 200 of the board unit 20 described later. In other words, the detection line 13a transmits information such as the voltage and temperature of the storage element 11 to the board 200 of the board unit 20 via the connector 13b. In addition, the detection line 13a also has the function of discharging the storage element 11 with a high voltage by controlling the substrate 200, thereby balancing the voltage between the storage elements 11.

The exterior body 18 is a rectangular (box-shaped) container (module case) that constitutes the exterior body of the energy storage unit 10. In other words, the exterior body 18 is disposed outside the energy storage elements 11, etc., and fixes the energy storage elements 11, etc. in a predetermined position to protect them from impacts, etc. Here, the exterior body 18 has an exterior body main body 14 that constitutes the main body of the exterior body 18, an exterior body support 15 that supports the exterior body main body 14, and an exterior body lid 17 that constitutes the lid (outer lid) of the exterior body 18.

The exterior body 14 is a rectangular cylindrical housing with a bottom and an opening. The exterior body 14 is made of an insulating material, such as PC, PP, or PE, similar to the board housing portion 100 of the board unit 20 described below.

The exterior body support 15 and the exterior body lid 17 are members that protect (reinforce) the exterior body main body 14. The exterior body support 15 and the exterior body lid 17 are formed from metal members such as stainless steel, aluminum, aluminum alloy, iron, plated steel sheet, etc. Note that the exterior body support 15 and the exterior body lid 17 may be formed from members of the same material or from members of different materials.

The exterior body support 15 is a member that supports the exterior body main body 14 from below (Z-axis negative direction) and has a bottom 15a, a board unit mounting part 16, and connection parts 15b and 15c. The bottom 15a is a flat and rectangular part that is parallel to the XY plane and extends in the Y-axis direction, constituting the bottom of the storage device 1, and is arranged below the exterior body main body 14. The board unit mounting part 16 is a flat and rectangular part that stands in the Z-axis positive direction from the end of the bottom 15a in the Y-axis negative direction, and the board unit 20 is attached to it. The connection part 15b is arranged at the end of the board unit mounting part 16 in the Z-axis positive direction, is a part that protrudes in the Y-axis negative direction, and is connected to the exterior body cover 17. The connection part 15c is a part that stands in the Z-axis positive direction from the end of the bottom 15a in the Y-axis positive direction, protrudes in the Y-axis positive direction, and is connected to the exterior body cover 17.

The exterior body cover 17 is a member arranged to cover the opening of the exterior body main body 14, and has a top surface portion 17a and connection portions 17b and 17c. The top surface portion 17a is a flat, rectangular portion that is parallel to the XY plane and extends in the Y-axis direction, constituting the upper surface portion of the storage device 1, and is arranged above the exterior body main body 14. The connection portion 17b is arranged at the end of the top surface portion 17a in the negative Y-axis direction, is a portion that protrudes in the negative Y-axis direction, and is connected to the connection portion 15b of the exterior body support body 15. The connection portion 17c is a portion that extends in the negative Z-axis direction from the end of the top surface portion 17a in the positive Y-axis direction, protrudes in the positive Y-axis direction, and is connected to the connection portion 15c of the exterior body support body 15. In this way, the exterior body support 15 and the exterior body lid 17 are configured to sandwich the exterior body main body 14 from above and below, and are fixed by connecting the connection parts 15b and 15c to the connection parts 17b and 17c with screws or the like.

The board unit 20 is a device capable of monitoring the state of the energy storage element 11 of the energy storage unit 10 and controlling the energy storage element 11. In this embodiment, the board unit 20 is a flat rectangular member attached to the longitudinal end of the energy storage unit 10, i.e., the side surface of the energy storage unit 10 in the negative Y-axis direction. Specifically, the board unit 20 is rotatably attached to the board unit attachment portion 16 provided on the exterior body support 15 of the exterior body 18 of the energy storage unit 10.

[2 Configuration of exhaust section and bus bar frame]
FIG. 3 is an exploded perspective view showing a schematic configuration of the exhaust unit 50 and the bus bar frame 12 according to the embodiment.

As shown in FIG. 3, the exhaust section 50 has an exhaust member 60 and a cover member 65. The exhaust member 60 is disposed directly above the gas exhaust valves 111 of each energy storage element 11. The exhaust member 60 is formed in a U-shape with an open upper end when viewed in the Y-axis direction, and is a resin member that is long in the Y-axis direction. The bottom of the exhaust member 60 has a plurality of holes 61 formed therein to expose the gas exhaust valves 111 of each energy storage element 11.

The exhaust member 60 may be formed from a resin that is more heat resistant than the bus bar frame 12. For example, if the bus bar frame 12 is formed from PP, the exhaust member 60 may be formed from polyphenylene sulfide (PPS), which has a higher heat resistance than PP. Here, if the bus bar frame and the exhaust member are integrally molded from a single resin, they must all be molded from a highly heat resistant resin. However, in this embodiment, only the exhaust member 60, which is separate from the bus bar frame 12, needs to be formed from a highly heat resistant resin, so the amount of resin used can be reduced.

The cover member 65 is disposed above the exhaust member 60 and closes the open portion of the exhaust member 60. Specifically, the cover member 65 is formed in a U-shape with an open lower portion when viewed in the Y-axis direction, and is a long member in the Y-axis direction. The cover member 65 is made of metal and has higher heat dissipation properties than the exhaust member 60. One end of the cover member 65 in the Y-axis positive direction is open at the lower end and at the tip end while protruding from the exhaust member 60. On the other hand, the other end of the cover member 65 is closed, preventing the discharge of gas. The cover member 65, when housed in the exhaust member 60, constitutes a gas exhaust path 59 together with the exhaust member 60. Gas is discharged from the open portion at one end of the cover member 65 described above. In other words, one end of the cover member 65 is the exhaust port portion 51 through which gas is discharged. The exhaust port portion 51 protrudes outward from the end of the busbar frame 12 in the Y-axis positive direction. Therefore, gas discharged from the gas exhaust valve 111 of each energy storage element 11 enters the exhaust path 59 formed by the exhaust member 60 and the cover member 65 through the hole 61 of the exhaust member 60. The gas then passes through the exhaust path 59 and is discharged outside the energy storage unit 10 from the exhaust port 51 located outside the bus bar frame 12.

Next, the bus bar frame 12 will be described in detail. FIG. 4 is a top view showing a schematic configuration of the bus bar frame 12 according to the embodiment. FIG. 4 also shows the energy storage element 11, the bus bar 13, the positive power cable 31, the negative power cable 32, and multiple detection lines 13a.

As shown in Figures 3 and 4, the busbar frame 12 is an example of a busbar holding member that is arranged on the multiple energy storage elements 11 and holds the multiple busbars 13. Specifically, the busbar frame 12 has a first holding portion 71, a second holding portion 72, and a connecting portion 73. Here, of the multiple detection lines 13a, the multiple detection lines 13a held by the first holding portion 71 are referred to as first detection lines 13a1. Also, of the multiple detection lines 13a, the multiple detection lines 13a held by the second holding portion 72 are referred to as second detection lines 13a2.

The first holding portion 71 is a portion on the X-axis positive side (one side) of the bus bar frame 12, and holds the first bus bar group 131 and the positive power cable 31. The first holding portion 71 also holds the electrode terminals (positive electrode terminals 11b or negative electrode terminals 11c) in the X-axis positive direction of each storage element 11, or a plurality of first detection lines 13a1 connected to the bus bars 13 included in the first bus bar group 131.

The first holding portion 71 is disposed in the positive direction of the X-axis from the gas exhaust valve 111 of each energy storage element 11. The first holding portion 71 has a first outer wall portion 711 that surrounds the outer periphery of the first holding portion 71, and a first surrounding wall 712 that, together with the first outer wall portion 711, surrounds each bus bar 13.

A pair of first notches 711a and 711b are formed at the end of the first outer wall portion 711 in the negative Y-axis direction. The first notch 711a of the pair of first notches 711a and 711b is arranged so that the positive power cable 31 and the multiple first detection lines 13a1 pass through it. The other first notch 711b is arranged so that the negative power cable 32 passes through it.

The first surrounding wall 712 is disposed on the positive side of the X-axis within the first outer wall portion 711, and is elongated in the Y-axis direction. The positive end of the first surrounding wall 712 on the Y-axis direction is disposed between the storage element 11 at the end on the positive Y-axis direction and the adjacent storage element 11. The negative end of the first surrounding wall 712 on the Y-axis direction extends to the vicinity of the first notch 711a of the first outer wall portion 711.

Within the first surrounding wall 712, there are provided a plurality of first partition walls 713 arranged between each bus bar 13, and a plurality of first partition portions 714 arranged between each energy storage element 11. The first partition walls 713 have a flat plate shape parallel to the XZ plane, and their upper end surfaces are flush with the upper end surface of the first outer wall portion 711. The first partition portions 714 are elongated portions in the X-axis direction, and are lower in height than the first partition walls 713. Each bus bar 13 is arranged so as to straddle the corresponding first partition portion 714.

Within the first outer wall portion 711, the area in the negative X-axis direction from the first surrounding wall 712 is a first cable path portion 715 that penetrates along the Y-axis direction. The first cable path portion 715 is disposed between the gas exhaust valve 111 of each energy storage element 11 and each bus bar 13 included in the first bus bar group 131. In this way, the first cable path portion 715 is disposed inward in the X-axis direction from the first bus bar group 131 within the bus bar frame 12.

The positive power cable 31 and the multiple first detection lines 13a1 are arranged in the first cable path section 715. The first cable path section 715 forms a path for the positive power cable 31 and the multiple first detection lines 13a1. In other words, the first cable path section 715 can also be called a first detection line path, which is the path for the multiple first detection lines 13a1. By being arranged in the first cable path section 715, the multiple first detection lines 13a1 and the positive power cable 31 are arranged between the first holding section 71 and the second holding section 72, that is, avoiding being arranged on the connecting section 73.

Within the first cable path section 715, the positive power cable 31 and the multiple first detection lines 13a1 are each arranged in a position generally along the Y-axis direction. The first cable path section 715 has a guide section 80 that guides one end of the positive power cable 31. The first cable path section 715 also has multiple detection line holding sections 90 that hold the first detection lines 13a1. Details of the guide section 80 and the detection line holding sections 90 will be described later.

The second holding portion 72 is a portion of the busbar frame 12 on the negative X-axis side (the other side). The second holding portion 72 holds the second busbar group 132 and the electrode terminals (positive electrode terminals 11b or negative electrode terminals 11c) in the negative X-axis direction of each storage element 11, or a plurality of second detection lines 13a2 connected to the busbars 13 included in the second busbar group 132.

The second holding portion 72 is disposed in the negative X-axis direction relative to the gas exhaust valve 111 of each storage element 11. The second holding portion 72 has a second outer wall portion 721 that surrounds the outer periphery of the second holding portion 72, and a second surrounding wall 722 that, together with the second outer wall portion 721, surrounds each bus bar 13.

A second notch 721a is formed at the end of the second outer wall portion 721 in the negative Y-axis direction. A plurality of second detection lines 13a2 are arranged to pass through the second notch 721a.

The second surrounding wall 722 is disposed on the negative X-axis side within the second outer wall portion 721, and is elongated in the Y-axis direction. The end of the second surrounding wall 722 in the positive Y-axis direction is continuous with the end of the second outer wall portion 721 in the positive Y-axis direction. In addition, the end of the second surrounding wall 722 in the negative Y-axis direction extends to the vicinity of the second notch 721a of the second outer wall portion 721.

In the region of the second surrounding wall 722 on the negative X-axis direction side, there are provided a plurality of second partition walls 723 arranged between the bus bars 13, and a plurality of second partition portions 724 arranged between the energy storage elements 11. The second partition walls 723 have a flat plate shape parallel to the XZ plane, and their upper end surfaces are flush with the upper end surface of the second outer wall portion 721. The second partition portions 724 are elongated portions in the X-axis direction, and are lower in height than the second partition walls 723. Each bus bar 13 is arranged to straddle the corresponding second partition portion 724.

Within the second outer wall portion 721, the area on the positive side of the second surrounding wall 722 in the X-axis direction is a second cable path portion 725 that penetrates along the Y-axis direction. The second cable path portion 725 is disposed between the gas exhaust valve 111 of each energy storage element 11 and each bus bar 13 included in the second bus bar group 132. In this way, the second cable path portion 725 is disposed inside the second bus bar group 132 in the X-axis direction within the bus bar frame 12.

The second cable path section 725 has a plurality of second detection lines 13a2 arranged therein. The second cable path section 725 can be considered a second detection line path, which is the path of the plurality of second detection lines 13a2. By being arranged within the second cable path section 725, the plurality of second detection lines 13a2 are arranged between the first holding section 71 and the second holding section 72, i.e., avoiding being located on the connecting section 73.

In the second cable path section 725, each of the multiple second detection lines 13a2 is arranged in a posture generally along the Y-axis direction. In the second cable path section 725, multiple detection line locking portions 99 that lock each second detection line 13a2 are provided. The multiple detection line locking portions 99 are arranged along the Y-axis direction. The detection line locking portion 99 is a long protrusion in the X-axis direction, and a space through which the second detection line 13a2 passes in the Y-axis direction is formed below it. The second detection line 13a2 passes through this space, so that the detection line locking portion 99 suppresses the floating of the second detection line 13a2. All of the multiple detection line locking portions 99 have the same shape, but the number of second detection lines 13a2 that they lock is different. Specifically, as shown in FIG. 4, the detection line locking portion 99 farthest from the second notch 721a, that is, the detection line locking portion 99 arranged furthest in the Y-axis positive direction, holds one second detection line 13a2. From there, it is possible to increase the number of second detection lines 13a2 that each detection line locking portion 99 locks by one as one moves toward the negative Y-axis direction. Note that in locations where there are a large number of second detection lines 13a2, one detection line locking portion 99 may or may not hold all of the second detection lines 13a2.

3 and 4, the connecting portion 73 is a portion that connects the first holding portion 71 and the second holding portion 72. Specifically, the connecting portion 73 has a plurality of beam portions 731 that are long in the X-axis direction and have one end connected to the first holding portion 71 and the other end connected to the second holding portion 72. The plurality of beam portions 731 are arranged at a predetermined interval in the Y-axis direction. Among the plurality of beam portions 731, the beam portion 731 at the end in the negative Y-axis direction is arranged outside the storage element 11 at the end in the negative Y-axis direction. In addition, the beam portion 731 at the end in the positive Y-axis direction is arranged outside the storage element 11 at the end in the positive Y-axis direction. The other beam portions 731 are arranged between a pair of adjacent storage elements 11. In this way, the plurality of beam portions 731 are arranged in a position that is retreated from the gas exhaust valve 111 of each storage element 11. In other words, the gas exhaust valve 111 of each energy storage element 11 is exposed from multiple beam portions 731 when viewed from above.

[3 Beam section]
Fig. 5 is an explanatory diagram showing the positional relationship between the beam portion 731 and the energy storage element 11 according to the embodiment. Specifically, Fig. 5 is a diagram showing a cross section including the V-V line in Fig. 4. In Fig. 5, the energy storage element 11 is shown in a plan view, and the beam portion 731 is shown in a cross section. Fig. 6 is a cross section showing the positional relationship between the beam portion 731 and the exhaust unit 50 according to the embodiment. Specifically, Fig. 6 is a cross section cut at the position of the beam portion 731 in the XZ plane.

As shown in Figures 5 and 6, a recess 732 is formed in the center of the X-axis direction on the upper surface of the beam portion 731. The bottom surface 733 of the recess 732 constitutes the upper end surface of a portion of the beam portion 731 and is formed in a plane parallel to the XY plane. The bottom surface 733 of the recess 732 is located below the upper surface 11e of the container 11a (main body) of the energy storage element 11 (see Figure 5). Note that it is sufficient that the upper end surface of the portion of the beam portion 731 is located below the upper end of the container 11a of the energy storage element 11 (the portion located most positive in the Z-axis direction). In addition, the upper end surface of the portion of the beam portion 731 may be located flush with the upper surface of the container 11a.

As shown in FIG. 6, the lower end of the exhaust member 60 is disposed in the recess 732. To be more specific, a convex portion 62 protruding downward is formed in a portion of the lower surface of the exhaust member 60 corresponding to the beam portion 731. This convex portion 62 is accommodated in the recess 732 of the beam portion 731. The exhaust member 60 is positioned relative to the busbar frame 12 by disposing the convex portion 62 in the recess 732. The strength of the exhaust member 60 is also increased by thickening the portion where the convex portion 62 is present. Here, it is possible to thicken the exhaust member 60 by bulging the inner bottom surface, but in this case, the exhaust path 59 may be narrowed, which may hinder smooth exhaust (see, for example, the two-dot chain line L5 in FIG. 6). In this embodiment, the convex portion 62 is provided on the lower surface of the exhaust member 60, thereby suppressing the narrowing of the exhaust path 59 while thickening a portion of the exhaust member 60. In particular, in this embodiment, the beam portion 731 has a recess 732, so the protrusion 62 can be made to protrude further into the recess 732, making it possible to increase the thickness.

In this way, the bottom surface 733 (upper end surface) of the recess 732, which is part of the beam portion 731, is located below the upper surface 11e of the container 11a of the energy storage element 11, so that space directly above that portion can be secured and part of the exhaust member 60 can be made thicker. In other words, the space efficiency within the energy storage device 1 is improved. Note that if improving the strength of the exhaust member 60 is a priority, the inner bottom surface of the exhaust member 60 may be bulged.

[4 Guide section]
Next, a detailed description will be given of the guide portion 80. Fig. 7 is a top view showing a schematic configuration of the guide portion 80 according to the embodiment.

As shown in FIG. 7, the guide portion 80 is a portion that guides one end of the positive power cable 31 in a position inclined with respect to the Y-axis direction within the first cable path portion 715. A general-purpose round terminal 311, for example, is attached to one end of the positive power cable 31. This round terminal 311 is screwed with a nut 312 together with the connection terminal 19 of the detection line 13a to the positive terminal 11b of the storage element 11 at the end in the positive direction of the Y-axis among the multiple storage elements 11. The guide portion 80 supports one end of the positive power cable 31 from the side, thereby guiding the one end in a position inclined with respect to the Y-axis direction.

Here, it is assumed that one end of the positive power cable 31 is disposed in a position perpendicular to the Y-axis direction, that is, one end of the positive power cable 31 is disposed along the X-axis direction. The positive power cable 31 is thicker and less likely to bend than the detection wire 13a, so if the one end is disposed in a position perpendicular to the Y-axis direction via the round terminal 311, it may protrude onto the connecting portion 73 side as shown by the dashed line L2 in FIG. 7. To allow this, the first holding portion 71 must be made larger in the negative X-axis direction, but this requires the exhaust portion 50 to be made smaller. In other words, the exhaust path 59 may be narrowed, which may reduce exhaust performance.

In this embodiment, the guide portion 80 guides one end of the positive power cable 31 in a position that is inclined with respect to the Y-axis direction, so that the positive power cable 31 does not have to be bent sharply. This makes it possible to accommodate the positive power cable 31 in the first cable path portion 715 without making the first holding portion 71 larger.

Specifically, the guide portion 80 is provided at the end of the first surrounding wall 712 in the positive direction of the Y axis. The end of the first surrounding wall 712 in the positive direction of the Y axis has a flat first wall 718 parallel to the XZ plane and a flat second wall 719 parallel to the YZ plane. The guide portion 80 is disposed between the first wall 718 and the second wall 719, and is a portion that connects the first wall 718 and the second wall 719. The guide portion 80 can also be said to be a corner portion provided at the end of the first surrounding wall 712 in the positive direction of the Y axis. The guide portion 80 is disposed between the storage element 11 disposed at the end of the first surrounding wall 712 in the positive direction of the Y axis among the multiple storage elements 11 and the bus bar 13 disposed at the end of the first bus bar group 131 in the positive direction of the Y axis, and functions as a barrier. For example, in the unlikely event that one end of the positive power cable 31 becomes detached from the storage element 11, or during connection or removal work, the guide portion 80 can prevent the one end of the positive power cable 31 from touching the bus bar 13.

The guide portion 80 is a flat wall, and its planar outer surface 81 supports one end of the positive power cable 31 from the side. This allows one end of the positive power cable 31 to be supported in a straight line. Here, the acute angle α between the outer surface 81 of the guide portion 80 and the Y-axis direction is less than 45 degrees. In other words, the one end of the positive power cable 31 guided by the guide portion 80 is also positioned at approximately the same angle with respect to the Y-axis direction. This makes it possible to reduce the moment applied to the connection between the one end of the positive power cable 31 and the storage element 11 when the other end of the positive power cable 31 is pulled in the negative Y-axis direction.

The first cable path section 715 is provided with a locking piece 717 that locks the positive power cable 31 at a location in the negative Y-axis direction from the guide section 80. Specifically, the locking piece 717 is disposed on an extension line (dashed line L3) of the guide section 80. The locking piece 717 locks the boundary between the portion of the positive power cable 31 that is aligned in the Y-axis direction and the inclined portion. When the other end of the positive power cable 31 is pulled in the negative Y-axis direction, the locking piece 717 receives part of the tension. This makes it possible to further reduce the moment applied to the connection portion between one end of the positive power cable 31 and the storage element 11.

[5 Detection line holding unit]
4, one of the multiple detection line holding units 90 is disposed near the storage element 11 disposed at the end in the negative Y-axis direction. The remaining detection line holding units 90 are disposed near the storage element 11 in the negative Y-axis direction of a pair of storage elements 11 connected to one bus bar 13 in the first bus bar group 131. Since the detection line holding units 90 have substantially the same configuration, one detection line holding unit 90 will be described here as an example.

Figure 8 is a perspective view showing the schematic configuration of a detection line holding unit 90 according to an embodiment. Figure 9 is a cross-sectional view showing the schematic configuration of a detection line holding unit 90 according to an embodiment.

As shown in Figures 8 and 9, the detection line holding unit 90 holds a first detection line 13a1 that is connected to a storage element 11 near the detection line holding unit 90.

First, the connection terminal 19 of the first detection line 13a1 will be described. The connection terminal 19 is connected to the tip of the first detection line 13a1. The connection terminal 19 is made of sheet metal, and is formed in a stepped shape so that its base 191 is located above the tip 192. The base 191 is provided with a fixing claw 193 that fixes the tip of the first detection line 13a1. The fixing claw 193 and the base 191 clamp the first detection line 13a1 to fix the first detection line 13a1. The tip 192 of the connection terminal 19 has a hanging part 194 that hangs down continuously from the tip of the base 191, and an attachment part 195 that continues from the tip of the hanging part 194 and extends parallel to the base 191. The attachment part 195 is formed in a circular ring shape in a plan view (Z-axis direction view), and an electrode terminal (e.g., positive terminal 11b) of the storage element 11 is inserted into its opening. A nut 115 is screwed to the positive terminal 11b with the bus bar 13 and the mounting portion 195 passing through it. This fixes the bus bar 13 and the mounting portion 195 to the positive terminal 11b. The connection terminal of the second detection line 13a2 is the same as the connection terminal 19 of the first detection line 13a1.

Next, the detection line holding unit 90 will be described in detail. The detection line holding unit 90 holds a first detection line 13a1 and its connection terminal 19, which are connected to the storage element 11 near the detection line holding unit 90. In the following description, of the multiple first detection lines 13a1, the first detection line 13a1 connected to the storage element 11 near the detection line holding unit 90 will be referred to as a connection target line 13b1, and the other first detection lines 13a1 different from the connection target line 13b1 will be referred to as non-target lines 13c1.

Specifically, the detection line holding portion 90 is disposed above (in the positive direction of the Z axis) the inner bottom surface of the first cable path portion 715. The detection line holding portion 90 has a first wall portion 91, a second wall portion 92, a third wall portion 93, and a spring portion 94.

The first wall portion 91 is a portion that supports the base 191 of the connection terminal 19 from below. The first wall portion 91 is a flat portion that is disposed above the inner bottom surface of the first cable path portion 715 and parallel to the inner bottom surface. An opening 715a is formed in the inner bottom surface of the first cable path portion 715 in a portion that faces the first wall portion 91. Since the inner bottom surface of the first cable path portion 715 and the first wall portion 91 are spaced apart in the vertical direction, multiple asymmetric lines 13c1 are disposed in the space formed by the inner bottom surface and the first wall portion 91. At this time, the multiple asymmetric lines 13c1 are bridged over the opening 715a. On the other hand, the connection terminal 19 of the connection target line 13b1 is held above the multiple asymmetric lines 13c1 by being disposed on the first wall portion 91. In other words, in a plan view (Z-axis direction view), the connection terminal 19 and at least one of the multiple asymmetric lines 13c1 are disposed so as to overlap each other. The space formed by the inner bottom surface of the first cable path portion 715 and the first wall portion 91 must be large enough to allow at least one non-target wire 13c1 to overlap the connection terminal 19 of the target connection wire 13b1 in a plan view.

A pair of restricting protrusions 911 are provided on the upper surface of the first wall portion 91 and are arranged to sandwich the base 191 of the connection terminal 19 in the Y-axis direction. The base 191 is sandwiched between the pair of restricting protrusions 911, thereby positioning the connection terminal 19 in the Y-axis direction. In addition, the hanging portion 194 of the connection terminal 19 abuts against the end face of the first wall portion 91 on the side of the energy storage element 11 (the end face in the positive direction of the X-axis). This positions the connection terminal 19 in the X-axis direction.

The second wall portion 92 is a flat plate-shaped portion provided below the first wall portion 91 and sandwiching the first wall portion 91 in the Y-axis direction. The second wall portion 92 is also a part of the first surrounding wall 712. The second wall portion 92 is disposed at a position corresponding to the end of the first wall portion 91 in the positive direction of the X-axis. The second wall portion 92 is disposed between the hanging portion 194 of the connection terminal 19 and the asymmetric line 13c1. This allows the second wall portion 92 to act as a barrier, thereby suppressing interference between the asymmetric line 13c1 and the connection terminal 19. Furthermore, during assembly, the asymmetric line 13c1 can be reliably disposed at a position overlapping the connection terminal 19 in a plan view by sliding it along the inner bottom surface of the first cable path portion 715 and abutting against the second wall portion 92.

The third wall portion 93 is erected on the upper surface of the first wall portion 91 at the end facing the positive direction of the Y axis and the end facing the negative direction of the X axis. In other words, the third wall portion 93 is disposed between the positive power cable 31 and the connection terminal 19. The third wall portion 93 acts as a barrier, preventing interference between the positive power cable 31 and the connection terminal 19.

The spring portion 94 is a portion that regulates the connection terminal 19. Specifically, the spring portion 94 has a pair of leaf springs 941. The pair of leaf springs 941 are disposed above the first wall portion 91 and face each other at a predetermined interval in the Y-axis direction. Each of the pair of leaf springs 941 is a rod-shaped body hanging down from the upper end of the detection line holding portion 90. Each of the pair of leaf springs 941 is inclined so as to approach the other leaf spring 941 as it goes downward. In other words, the distance between the pair of leaf springs 941 in the Y-axis direction is narrowest at the lower end and widest at the upper end. During assembly, when the base 191 of the connection terminal 19 is disposed between the pair of leaf springs 941 and lowered along the pair of leaf springs 941, the pair of leaf springs 941 elastically deform to allow the connection terminal 19 to lower. When the base 191 of the connection terminal 19 passes the lower ends of the pair of leaf springs 941, the pair of leaf springs 941 return to their original shape. At this time, the lower ends of the pair of leaf springs 941 are positioned directly above the base 191 of the connection terminal 19. In other words, the pair of leaf springs 941 hold the base 191 of the connection terminal 19. As a result, the pair of leaf springs 941 restrict the upward movement of the connection terminal 19, and the connection terminal 19 is positioned in the up-down direction.

Here, all of the detection line holding parts 90 have the same shape, but the number of asymmetric lines 13c1 arranged in the space formed by the inner bottom surface of the first cable path part 715 and the first wall part 91 is different. Specifically, as shown in FIG. 4, the detection line holding part 90 furthest from the first notch 711a, that is, the detection line holding part 90 arranged furthest in the positive direction of the Y axis, does not have asymmetric lines 13c1 arranged in the space. It is possible to increase the number of asymmetric lines 13c1 arranged in the space by one line as it moves toward the negative direction of the Y axis. Note that in a location where the number of asymmetric lines 13c1 is large, all of the asymmetric lines 13c1 may or may not be arranged in the space of one detection line holding part 90.

[6. Description of Effects]
As described above, the energy storage device 1 according to this embodiment includes a plurality of energy storage elements 11 arranged along the Y-axis direction (a predetermined direction), a plurality of bus bars 13 electrically connected to the plurality of energy storage elements 11, a bus bar frame 12 (bus bar holding member) arranged on the plurality of energy storage elements 11 and holding the plurality of bus bars 13, and a positive power cable 31 (power cable) electrically connected to one of the plurality of energy storage elements 11, the bus bar frame 12 being arranged inwardly of the plurality of bus bars 13 and having a first cable path portion 715 (cable path portion) in which the positive power cable 31 is arranged in an orientation along the Y-axis direction, and the first cable path portion 715 having a guide portion 80 that guides one end of the positive power cable 31 connected to one of the energy storage elements 11 into an orientation inclined with respect to the Y-axis direction.

Accordingly, by inclining one end of the positive power cable 31 with respect to the arrangement direction (Y-axis direction) of the multiple storage elements 11, the amount of bending of the positive power cable 31 can be reduced while ensuring installation space for the connection structure compared to when the end is perpendicular. In other words, it becomes possible to adopt a general-purpose round terminal 311, for example. In this way, the bus bar frame 12 is provided with a guide portion 80 that guides one end of the positive power cable 31 into a position inclined with respect to the Y-axis direction, so that it is possible to stably hold one end of the positive power cable 31 while reducing the burden on the positive power cable 31.

In addition, each of the multiple storage elements 11 has a gas exhaust valve 111, and the gas exhaust valves 111 are arranged in a position facing the same direction, and the first cable path portion 715 is arranged between the multiple bus bars 13 and each of the gas exhaust valves 111 of the multiple storage elements 11.

As a result, since the first cable path section 715 is disposed between the multiple bus bars 13 and the gas exhaust valves 111 of each of the multiple storage elements 11, the positive power cable 31 in the first cable path section 715 is also disposed in a position retracted from the gas exhaust valve 111. This makes it possible to reduce exposure of the positive power cable 31 to the gas exhausted from the gas exhaust valve 111. This makes it possible to reduce the burden on the positive power cable 31 during gas exhaust.

In addition, because the guide portion 80 is planar, one end of the positive power cable 31 can be guided in a straight line. This further reduces the strain on the positive power cable 31.

In addition, the acute angle α between the guide portion 80 and the Y-axis direction is less than 45 degrees.

As a result, the acute angle α between the guide portion 80 and the Y-axis direction is less than 45 degrees, so one end of the positive power cable 31 guided by the guide portion 80 is also positioned at approximately the same angle with respect to the Y-axis direction. This makes it possible to reduce the moment applied to the connection between one end of the positive power cable 31 and the storage element 11 when the other end of the positive power cable 31 is pulled. This makes it possible to stabilize the connection between one end of the positive power cable 31 and the storage element 11.

The guide portion 80 is also disposed between one of the multiple bus bars 13 and one storage element 11.

As a result, the guide portion 80 is disposed between one of the bus bars 13 and one of the storage elements 11. Therefore, even if one end of the positive power cable 31 becomes detached from the storage element 11, the guide portion 80 acts as a barrier to prevent interference with the bus bar 13 or other storage elements 11.

In addition, the energy storage device 1 according to this embodiment includes a plurality of energy storage elements 11 each having a gas exhaust valve 111 and arranged with the gas exhaust valves 111 facing the same direction, a plurality of bus bars 13 electrically connected to the plurality of energy storage elements 11, and a bus bar frame 12 (bus bar holding member) arranged on the plurality of energy storage elements 11 and holding the plurality of bus bars 13. The energy storage element 11 includes a container 11a (main body) having a gas exhaust valve 111 on its upper surface, and a pair of electrode terminals (positive terminal 11b and negative electrode terminal 11c), and the bus bar frame 12 has a first holding portion 71 arranged on one side of the gas exhaust valve 111 on the multiple storage elements 11, a second holding portion 72 arranged on the other side of the gas exhaust valve 111 on the multiple storage elements 11, and a beam portion 731 arranged between at least a pair of adjacent storage elements 11 among the multiple storage elements 11 and connecting the first holding portion 71 and the second holding portion 72, and a part of the upper end surface (bottom surface 733) of the beam portion 731 is arranged below or flush with the upper surface 11e of the container 11a.

As a result, the beam portion 731 is disposed between at least a pair of adjacent energy storage elements 11, so that the gas exhaust valve 111 of each energy storage element 11 is exposed. This makes it possible to prevent the beam portion 731 from being affected by the gas exhausted from the gas exhaust valve 111. In addition, since the bottom surface 733 of the beam portion 731 is disposed below or flush with the upper surface 11e of the container 11a of the energy storage element 11, it is possible to ensure space directly above that portion. This makes it possible to increase the space efficiency within the energy storage device 1. As a result, it is possible to suppress the effect of gas on the beam portion 731 while increasing the space efficiency within the energy storage device 1.

The beam portions 731 are also arranged between each of the adjacent pairs of storage elements 11.

With this, beam portions 731 are disposed between each of the adjacent pairs of energy storage elements 11, so that the first holding portion 71 and the second holding portion 72 are connected by the beam portions 731. This increases the rigidity of the busbar frame 12. Furthermore, the bottom surface 733 of each beam portion 731 is located below or flush with the upper surface 11e of the container 11a of the energy storage element 11, so that space can be secured directly above the portion of each beam portion 731. This allows for greater space efficiency within the energy storage device 1.

The energy storage device 1 also includes an exhaust member 60 that is disposed on the beam portion 731 of the busbar frame 12 and forms an exhaust path 59 for the gas exhausted from the gas exhaust valve 111.

As a result, since the exhaust member 60 is disposed on the beam portion 731, the exhaust member 60 can protect the beam portion 731 from gas. Therefore, the effect of gas on the beam portion 731 can be further suppressed.

In addition, the beam portion 731 has a recess 732 that forms the upper end surface of the portion, and the exhaust member 60 is disposed within the recess 732.

According to this, the beam portion 731 is provided with a recess 732 that forms an upper end surface (bottom surface 733) that is lower than or flush with the upper surface 11e of the container 11a of the energy storage element 11, and the exhaust member 60 is disposed within this recess 732, so that a portion of the exhaust member 60 can be disposed close to the upper surface of the container 11a of the energy storage element 11. This allows the exhaust member 60, i.e., the exhaust path 59, to be formed larger, enabling smooth exhaust of gas. Therefore, the temperature rise within the exhaust member 60 can be further suppressed.

In addition, a portion of the exhaust member 60 is disposed within the recess 732 of the beam portion 731, so that the exhaust member 60 can be positioned by the recess 732.

The energy storage device 1 also includes a plurality of detection lines 13a for detecting the respective states of the plurality of energy storage elements 11, the first holding portion 71 includes a first cable path portion 715 (first detection line path) which is the path of at least one first detection line 13a1 of the plurality of detection lines 13a, the second holding portion 72 includes a second cable path portion 725 (second detection line path) which is the path of a second detection line 13a2 other than the at least one first detection line 13a1 of the plurality of detection lines 13a, and the first detection line 13a1 and the second detection line 13a2 are arranged to avoid being between the first holding portion 71 and the second holding portion 72.

Accordingly, the first detection line 13a1 is arranged in the first cable path section 715, avoiding the gap between the first holding section 71 and the second holding section 72. On the other hand, the second detection line 13a2 is arranged in the second cable path section 725, avoiding the gap between the first holding section 71 and the second holding section 72. In this way, since the first detection line 13a1 and the second detection line 13a2 are arranged in a manner avoiding the gap between the first holding section 71 and the second holding section 72, the space between the first holding section 71 and the second holding section 72, i.e., the space directly above the beam section 731, can be more secure.

In addition, since the first detection line 13a1 and the second detection line 13a2 are arranged between the first holding portion 71 and the second holding portion 72, i.e., away from the gas exhaust valve 111, the first detection line 13a1 and the second detection line 13a2 are less likely to be exposed to the gas exhausted from the gas exhaust valve 111.

In addition, the energy storage device 1 according to this embodiment includes a plurality of storage elements 11 arranged along the Y-axis direction (a predetermined direction), a plurality of bus bars 13 electrically connected to the plurality of storage elements 11, a plurality of detection lines 13a electrically connected to each of the at least two storage elements 11 in order to detect the state of at least two of the plurality of storage elements 11, and a bus bar frame 12 (bus bar holding member) arranged on the plurality of storage elements 11 and holding the plurality of bus bars 13 and the plurality of detection lines 13a. The bus bar frame 12 has a detection line holding portion 90 arranged near one of the at least two storage elements 11 and holding the connection terminal 19 of the connection target line 13b1 connected to the storage element 11 above the non-target line 13c1 connected to the other storage element 11.

With this, since the detection line holding portion 90 holds the connection terminal 19 of the connection target line 13b1 above the non-target line 13c1, the connection terminal 19 and the non-target line 13c1 can be arranged to overlap when viewed from above. This makes it difficult for the connection terminal 19 and the non-target line 13c1 to be arranged to spread out in a plan view, thereby saving space.

In particular, in this embodiment, since the first cable path section 715 contains multiple first detection lines 13a1 and positive power cables 31, there are greater space constraints than in the second cable path section 725. However, as described above, if the connection terminal 19 and the asymmetric line 13c1 can be arranged to overlap each other when viewed from above, it is possible to ensure space for the positive power cables 31 within the first cable path section 715.

The detection line holding portion 90 holds the connection terminal 19 in a position that overlaps the asymmetric line 13c1 when viewed in a plane.

As a result, the connection terminal 19 is positioned so as to overlap the asymmetric line 13c1 in a plan view, so that the connection terminal 19 and the asymmetric line 13c1 can be reliably arranged to overlap each other. This makes it possible to more reliably save space.

The detection line holding portion 90 also has a first wall portion 91 that is interposed between the connection terminal 19 of the held connection target line 13b1 and the non-target line 13c1.

With this, the first wall portion 91 of the detection line holding portion 90 is interposed between the connection terminal 19 that it holds and the asymmetric line 13c1, so that the connection terminal 19 can be prevented from interfering with the asymmetric line 13c1. This can prevent the connection terminal 19 from damaging the asymmetric line 13c1, and can prevent the occurrence of a short circuit caused by the damage. This eliminates the need to provide a dedicated member for preventing short circuits, allowing for further space savings.

The detection line holding portion 90 also has a spring portion 94 that regulates the connection terminal 19.

As a result, the detection line holding portion 90 has a spring portion 94 that regulates the connection terminal 19, so that the spring portion 94 can suppress misalignment of the connection terminal 19.

The detection line holding portion 90 also has a first wall portion 91 that restricts the asymmetric line 13c1 passing below the detection line holding portion 90 from above, and a second wall portion 92 that restricts the asymmetric line 13c1 from one side.

As a result, the first wall portion 91 of the detection line holding portion 90 restricts the upward movement of the non-target line 13c1, and the second wall portion 92 restricts the lateral movement of the non-target line 13c1, thereby preventing the non-target line 13c1 from moving and interfering with the connection terminal 19.

The connection terminal 19 is formed in a stepped shape so that the base 191 is located above the tip 192 that is connected to the energy storage element 11, and the detection line holding portion 90 holds the base 191 of the connection terminal 19.

With this, the connection terminal 19 is formed in a stepped shape, and the base 191, which is located above the tip 192 connected to the storage element 11, is held by the detection line holding part 90, so that a space for the asymmetric line 13c1 can be easily formed below the detection line holding part 90.

[7. Description of Modifications]
Although the storage device 1 according to the present embodiment has been described above, the present invention is not limited to the above embodiment. In other words, the embodiment disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope of the claims.

For example, in the above embodiment, the guide portion 80 is a corner of the first surrounding wall 712, but the guide portion may be a separate part from the first surrounding wall 712. In this case, the shape of the guide portion can be determined independently of the first surrounding wall 712. For example, if the guide portion is integrated with the locking piece 717, one end of the positive power cable 31 can be supported over a wider area.

In addition, in the above embodiment, the acute angle α formed by the outer surface 81 of the guide portion 80 and the Y-axis direction is less than 45 degrees, but it may be 45 degrees or more.

In addition, in the above embodiment, the guide portion 80 supports one end of the positive power cable 31 from the side, but the guide portion 80 may support the round terminal 311 of the positive power cable 31 from the side.

In addition, in the above embodiment, the outer surface 81 of the guide portion 80 is flat, but the outer surface of the guide portion may be a concave or convex curved surface. From the viewpoint of absorbing the tension when the other end of the positive power cable 31 is pulled, it is preferable that the outer surface of the guide portion is a convex curved surface.

In addition, in the above embodiment, a case where the beam portion 731 is disposed between all of the adjacent pairs of storage elements 11 is illustrated, but it is sufficient that the beam portion is disposed between at least one pair of storage elements.

In addition, in the above embodiment, the exhaust member 60 is disposed directly above the beam portion 731. However, the member disposed directly above the beam portion 731 may be a member other than the exhaust member 60. Even in this case, the upper end surface of a portion of the beam portion is disposed below or flush with the upper surface 11e of the container 11a of the energy storage element 11, so that a larger installation space for other members can be secured.

In the above embodiment, the beam portion 731 has a recess 732. However, the beam portion may have a uniform shape over its entire length. In this case, the entire upper surface of the beam portion may be positioned below or flush with the upper surface 11e of the container 11a of the energy storage element 11.

In addition, in the above embodiment, the connection terminal 19 has a stepped shape, but the connection terminal 19 may be flat.

In addition, in the above embodiment, the detection line holding portion 90 and the detection line engaging portion 99 have different configurations, but the detection line engaging portion 99 may have the same configuration as the detection line holding portion 90. In this case, the space efficiency within the second cable path portion 725 is improved, so it is also possible to newly accommodate a member different from the second detection line 13a2 within the second cable path portion 725.

In addition, in the above embodiment, the case where the detection line 13a is connected to all of the multiple storage elements 11 is exemplified. However, for example, in the case of a detection line for temperature detection, the detection line may not be connected to all of the multiple storage elements. In other words, the detection line for temperature detection may be electrically connected to at least two storage elements to detect the state of at least two storage elements among the multiple storage elements. Specifically, the detection line for temperature detection may be connected only to the storage elements at both ends and the central storage element in the Y-axis direction. Even in this case, the detection line holding unit is disposed near one of the at least two storage elements, and the connection terminal of the detection line connected to the storage element may be held above the other detection line connected to the other storage element. Even in this case, the connection terminal of the detection line connected to the storage element and the other detection lines are less likely to be arranged in a planar manner, and space can be saved.

Figure 10 is a cross-sectional view showing a schematic configuration of the detection line holding unit 715b according to the first modified example. Figure 10 is a view corresponding to Figure 9. As shown in Figure 10, in the detection line holding unit 715b, the asymmetric line 13c1 is arranged below the positive power cable 31. In this way, the asymmetric line 13c1 may be arranged below the positive power cable 31. This makes it possible to suppress the floating of the asymmetric line 13c1 in the positive power cable 31. Note that, although Figure 10 shows a case in which all the asymmetric lines 13c1 are arranged below the positive power cable 31, it is sufficient that at least one asymmetric line 13c1 is arranged below the positive power cable 31. It is sufficient that the remaining asymmetric lines 13c1 are arranged below the detection line holding unit 90.

11 is a perspective view showing the vicinity of the guide portion 80 of the busbar frame 12b according to the second modification. As shown in FIG. 11, the busbar frame 12b has a slope portion 89b near the guide portion 80. Specifically, the slope portion 89b is an inner bottom surface of the first cable path portion 715 and is disposed near the guide portion 80. More specifically, the slope portion 89b is disposed in a position adjacent to the outer surface 81 of the guide portion 80b. The slope portion 89b is a groove portion extending along the outer surface 81. The positive power cable 31 is accommodated in the slope portion 89b. The bottom surface of the slope portion 89b is inclined so as to be lower toward the positive terminal 11b. In other words, the thickness of the bottom of the slope portion 89b becomes thinner toward the positive terminal 11b. Since the bottom surface of the slope portion 89b is inclined in this manner, the angular portion in the slope portion 89b is less likely to come into contact with the positive power cable 31. Therefore, damage to the positive power cable 31 can be suppressed. In addition, because the positive power cable 31 is housed within the slope portion 89b, it is also possible to suppress misalignment of the positive power cable 31. When one end of the positive power cable 31 is housed within the slope portion 89b, it is inclined with respect to the Y-axis direction. In other words, the slope portion 89b can be said to be an example of a guide portion according to the present disclosure.

In addition, the present invention can be realized not only as an energy storage device 1, but also as a busbar frame 12 (busbar holding portion) that holds multiple busbars.

In addition, configurations constructed by arbitrarily combining the components of the above-described embodiments and their variations are also included within the scope of the present invention.

The present invention can be applied to energy storage devices equipped with energy storage elements such as lithium-ion secondary batteries.

1 Energy storage device 10 Energy storage unit 11 Energy storage element 11a Container (main body)
11b Positive electrode terminal (electrode terminal)
11c negative electrode terminal (electrode terminal)
11d: Spacer 11e: Upper surface 12, 12b: Bus bar frame (bus bar holding member)
13 Bus bar 13a Detection line 13a1 First detection line 13a2 Second detection line 13b Connector 13b1 Connection target line 13c1 Non-target line (other detection line)
14 Exterior body main body 15 Exterior body support 15a Bottom 15b, 15c, 17b, 17c Connection portion 16 Board unit attachment portion 17 Exterior body cover 17a Top surface portion 18 Exterior body 19 Connection terminal 20 Board unit 30 Cable 31 Positive power cable (power cable)
32 Negative power cable 50 Exhaust portion 51 Exhaust port portion 59 Exhaust path 60 Exhaust member 61 Hole portion 62 Convex portion 65 Cover member 71 First holding portion 72 Second holding portion 73 Connection portion 80 Guide portion 81 Outer surface 89b Slope portion 90 Detection line holding portion 91 First wall portion 92 Second wall portion 93 Third wall portion 94 Spring portion 99 Detection line locking portion 100 Substrate accommodating portion 111 Gas exhaust valve 115, 312 Nut 131 First busbar group 132 Second busbar group 191 Base portion 192 Tip portion 193 Fixing claw 194 Hanging portion 195 Mounting portion 200 Substrate 311 Round terminal 711 First outer wall portion 711a, 711b First notch 712 First surrounding wall 713 First partition wall 714 First partition portion 715 First cable path section (cable path section, first detection line path)
715a Opening 715b Detection line holding portion 717 Locking piece 718 First wall 719 Second wall 721 Second outer wall portion 721a Second notch 722 Second surrounding wall 723 Second partition wall 724 Second partition portion 725 Second cable path portion (second detection line path)
731 Beam portion 732 Recess 733 Bottom surface (upper end surface)
911 Restriction protrusion 941 Leaf spring L2 Broken line L3 Broken line L5 Two-dot chain line α Angle

Claims (3)

A plurality of storage elements arranged along a predetermined direction;
A plurality of bus bars electrically connected to the plurality of energy storage elements;
a bus bar holding member arranged on the plurality of energy storage elements and holding the plurality of bus bars;
a power cable electrically connected to one of the plurality of power storage elements,
the bus bar holding member is disposed inwardly of the plurality of bus bars and has a cable path portion in which the power cable is disposed in a position along the predetermined direction,
the cable path portion has a guide portion that guides one end of the power cable connected to one of the energy storage elements into a position inclined with respect to the predetermined direction,
The guide portion is formed in a flat shape,
The acute angle between the guide portion and the predetermined direction is less than 45 degrees.
Energy storage device. The plurality of energy storage elements each have a gas exhaust valve, and are arranged in such a manner that the gas exhaust valves face in the same direction;
The energy storage device according to claim 1 , wherein the cable path portion is arranged between the bus bars and the gas release valve of each of the energy storage elements. The energy storage device according to claim 1 , wherein the guide portion is disposed between one of the plurality of bus bars and the one energy storage element.

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