ENERGY STORAGE APPARATUS

An energy storage apparatus includes: an energy storage device; a substrate in which a through hole penetrating a main surface is formed; a through member that penetrates the through hole; and a lateral member disposed lateral to the substrate and covering a side surface of the substrate. The lateral member includes an opening through which at least one of two portions of the through member, the two portions sandwiching the through hole, is visually recognizable from the outside.

TECHNICAL FIELD

The present invention relates to an energy storage apparatus including an energy storage device and a substrate.

BACKGROUND ART

Conventionally, an energy storage apparatus including an energy storage device and a substrate is widely known. Patent Document 1 discloses a vehicle battery system (energy storage apparatus) including a battery block made up of a plurality of battery cells (energy storage devices) and a circuit board (substrate) that detects a state of each battery cell, with the circuit board fixed to the battery block.

PRIOR ART DOCUMENTS

Patent Document

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In the energy storage apparatus, a member (hereinafter referred to as a lateral member) may be disposed lateral to the substrate. In such a case, there is a possibility that the state of penetration of the through member into the substrate cannot be grasped. When the state of penetration of the through member into the substrate cannot be grasped, there is a possibility that a defect due to attachment failure or the like of the through member to the substrate occurs.

An object of the present invention is to provide an energy storage apparatus in which a state of penetration of a through member into a substrate can be easily grasped.

Means for Solving the Problems

An energy storage apparatus according to one aspect of the present invention includes: an energy storage device; a substrate in which a through hole penetrating a main surface is formed; a through member that penetrates the through hole; and a lateral member disposed lateral to the substrate and covering a side surface of the substrate. The lateral member includes an opening through which at least one of two portions of the through member, the two portions sandwiching the through hole, is visually recognizable from an outside.

The present invention can be realized not only as such an energy storage apparatus but also as a lateral member including the opening and can also be realized as a lateral member, a substrate, and a through member.

Advantages of the Invention

According to the energy storage apparatus of the present invention, the state of penetration of the through member into the substrate can be easily grasped.

MODE FOR CARRYING OUT THE INVENTION

In Patent Document 1 described above, a voltage detection line (hereinafter referred to as a through member) connected to an electrode terminal of an energy storage device is fixed to a substrate in a state where the voltage detection line penetrates the through hole of the substrate (cf.FIG.12and the like of Patent Document 1). In the energy storage apparatus, various members are disposed in a small space in order to achieve space saving or the like, and thus, a member (hereinafter referred to as a lateral member) may be disposed lateral to the substrate. The inventor of the present application has found that in such a case, there is a possibility that the state of penetration of the through member into the substrate, such as whether the through member is reliably fixed to the substrate, cannot be grasped due to a difficulty in confirming the vicinity of the through hole of the substrate from the side of the substrate. When the state of penetration of the through member into the substrate cannot be grasped, there is a possibility that a defect due to attachment failure or the like of the through member to the substrate occurs.

The present invention has been made by the inventor of the present application focusing newly on the above problem, and an object of the present invention is to provide an energy storage apparatus in which a state of penetration of a through member into a substrate can be easily grasped.

An energy storage apparatus according to one aspect of the present invention includes: an energy storage device; a substrate in which a through hole penetrating a main surface is formed; a through member that penetrates the through hole; and a lateral member disposed lateral to the substrate and covering a side surface of the substrate. The lateral member includes an opening through which at least one of two portions of the through member, the two portions sandwiching the through hole, is visually recognizable from an outside.

According to this, in the energy storage apparatus, the lateral member disposed lateral to the substrate and covering the side surface of the substrate includes the opening through which at least one of two portions, sandwiching the through hole, in the through member that penetrates the through hole of the substrate is visually recognizable from the outside. In this manner, the opening is formed in the lateral member, and at least one of the two portions of the through member sandwiching the through hole of the substrate is made visually recognizable from the outside. Thereby, the portion penetrating the through hole of the through member is visually recognizable from the outside of the lateral member through the opening, so that the state of penetration of the through member into the substrate can be easily grasped.

The opening may be formed such that a portion closer to the energy storage device out of the two portions is visually recognizable.

According to this, the opening of the lateral member is formed such that the portion closer to the energy storage device out of the two portions sandwiching the through hole in the through member can be visually recognized. In the through member, the portion closer to the energy storage device out of the two portions sandwiching the through hole is located inside the energy storage apparatus, and it is thus difficult to grasp the state of the through member. Accordingly, an opening is formed in the lateral member such that the portion closer to the energy storage device can be visually recognized. As a result, the portion of the through member closer to the energy storage device, the portion being in a state of penetration difficult to grasp, is visually recognizable from the outside of the lateral member through the opening, so that the state of penetration of the through member can be easily grasped.

The through member may be a busbar connected to the energy storage device, and the busbar may include a busbar body, and a protrusion that projects from the busbar body, penetrates the through hole, and is joined to the substrate, and the opening may be formed such that a joined state of the protrusion to the substrate is visually recognizable.

According to this, the through member is the busbar connected to the energy storage device, and the opening of the lateral member is formed such that the joining state of the protrusion, which penetrates the through hole of the busbar and is joined to the substrate, can be visually recognized.

In order to measure the voltage of the energy storage device, a protrusion may be formed on the busbar, and the protrusion may be allowed to penetrate the through hole of the substrate and be joined (e.g., soldered) to the substrate. In this case, it is necessary to check whether the protrusion of the busbar is joined to the substrate (e.g., whether a solder fillet is formed favorably). Therefore, the opening is formed in the lateral member, and the joined state of the protrusion to the substrate can be visually recognized. As a result, the joined state of the protrusion of the busbar to the substrate can be easily grasped, so that it is possible to prevent stress concentration on the protrusion due to joint failure and to prevent the breakage of the protrusion.

The lateral member may be a busbar frame on which a busbar connected to the energy storage device is mounted, and the busbar frame may include a frame body, and a wall that projects from the frame body and covers a side surface of the substrate, and in which the opening is formed.

According to this, the lateral member is the busbar frame on which the busbar is placed, and the busbar frame includes the wall that covers the side surface of the substrate, and in which the opening is formed. In the energy storage apparatus, the busbar frame may be provided with a wall that covers the side surface of the substrate. For the purpose of preventing the movement (vibration) of the energy storage device in the outer case of the energy storage apparatus, or some other purpose, a wall may be provided on the busbar frame, and the wall may be engaged with the cover of the outer case to fix the busbar frame to the outer case. Alternatively, a wall may be provided on the busbar frame as a guide for disposing the cover on the outer case. In such a case, there is a possibility that the state of penetration of the through member into the substrate cannot be grasped due to the wall of the busbar frame. Therefore, the opening is formed in the wall of the busbar frame to make the state of penetration of the through member into the substrate visually recognizable. As a result, even if the wall is provided in the busbar frame, the state of penetration of the through member into the substrate can be easily grasped.

The opening may comprise a notch or a through hole formed in the lateral member.

According to this, since the opening of the lateral member is a notch or a through hole formed in the lateral member, by forming the notch or the through hole in the lateral member, it is possible to easily form the opening through which the state of penetration of the through member into the substrate can be visually recognized.

The through member may include a long side surface and a short side surface on a side surface in directions intersecting with a direction of penetration into the through hole, and the opening may be disposed to face the long side surface of the through member.

According to this, the opening of the lateral member is disposed to face the long side surface of the through member. As described above, by disposing the opening of the lateral member to face the long side surface of the through member instead of the short side surface thereof, it is possible to visually recognize the long side surface side of the through member instead of the short side surface thereof. This makes it easy to visually recognize the state of penetration of the through member, so that the state of penetration of the through member into the substrate can be easily and more reliably grasped.

Hereinafter, an energy storage apparatus according to an embodiment of the present invention (including a modification thereof) will be described with reference to the drawings. An embodiment described below illustrates a comprehensive or specific example. Numeral values, shapes, materials, components, placement positions and connection forms of the components, manufacturing steps, a sequence of the manufacturing steps, and the like shown in the following embodiment are only examples and are not intended to limit the present invention. In the drawings, dimensions and the like are not illustrated strictly. In the drawings, the same or similar components are denoted by the same reference numerals.

In the following description and drawings, a direction in which a pair of (positive-electrode-side and negative-electrode-side) electrode terminals are disposed in one energy storage device or a direction in which the short side surface of a case of the energy storage device faces is defined as an X-axis direction. A direction in which the energy storage devices are arranged or a direction in which the long side surface of the case of the energy storage device is defined as a Y-axis direction. A direction in which the body and the lid of the outer case of the energy storage apparatus are disposed, a direction in which the energy storage devices, the busbar frame, the busbar, and the substrate are disposed, or a vertical direction is defined as a Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction are mutually intersecting (orthogonal in the present embodiment) directions. It is conceivable that the Z-axis direction may not be the vertical direction depending on the use aspect, but for convenience of description, a description will be given below with the Z-axis direction as the vertical direction.

In the following description, an X-axis plus direction indicates an arrow direction of the X-axis, and an X-axis minus direction indicates a direction opposite to the X-axis plus direction. The same applies to the Y-axis direction and the Z-axis direction. Expressions indicating relative directions or postures, such as parallel and orthogonal, strictly include cases where the directions or postures are not the same. Two directions being orthogonal to each other not only means that the two directions are completely orthogonal to each other, but also means that the two directions are substantially orthogonal to each other, the two directions being orthogonal includes a difference of about several percent.

Embodiment

[1 General Description of Energy Storage Apparatus10]

First, an energy storage apparatus10according to the present embodiment will be generally described.FIG.1is a perspective view illustrating the appearance of the energy storage apparatus10according to the present embodiment.FIG.2is an exploded perspective view illustrating each component when the energy storage apparatus10according to the present embodiment is disassembled.

The energy storage apparatus10is an apparatus capable of charging electricity from the outside and discharging electricity to the outside and has a substantially rectangular parallelepiped shape in the present embodiment. The energy storage apparatus10is a battery module (assembled battery) used for power storage application, power supply application, or the like. Specifically, the energy storage apparatus10is used as a battery or the like for driving or starting an engine of a moving body such as an automobile, a motorcycle, a watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, or a railway vehicle for electric railways. Examples of the automobile include an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and a gasoline vehicle. Examples of the railway vehicle for electric railways include a train, a monorail, and a linear motor car. The energy storage apparatus10can also be used as a stationary battery or the like used for home use, a generator, or the like.

As illustrated inFIG.1, the energy storage apparatus10includes an outer case100, and as illustrated inFIG.2, a plurality of energy storage devices200, a busbar frame300, a busbar400, a substrate500, and the like are housed inside the outer case100. The energy storage apparatus10may include a spacer disposed between the plurality of energy storage devices200, a binding member (side plate, end plate, etc.) binding the plurality of energy storage devices200, and the like.

The outer case100is a case (module case) having a box shape (substantially rectangular parallelepiped shape) which forms an outer case of the energy storage apparatus10. That is, the outer case100is disposed outside the plurality of energy storage devices200, the busbar frame300, the busbar400, the substrate500, and the like, and fixes the energy storage devices200and the like at predetermined positions for protection from an impact or the like. The outer case100is formed of, for example, an insulating member such as polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), a polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyethersulfone (PES), an acrylonitrile butadiene styrene (ABS) resin, or a composite material thereof, or an insulation-coated metal. Thereby, the outer case100prevents the energy storage devices200and the like from coming into contact with an external metal member or the like. The outer case100may be formed of a conductive member such as metal so long as the electric insulation properties of the energy storage device200and the like are maintained.

The outer case100includes an outer case body110constituting the body of the outer case100and an outer case lid120constituting the lid of the outer case100. The outer case body110is a bottomed rectangular cylindrical housing (casing) in which an opening is formed, and houses the energy storage devices200and the like therein. The outer case lid120is a flat rectangular member that closes the opening of the outer case body110. The outer case lid120is engaged with or fitted to the outer case body110and is joined to the outer case body110by an adhesive, heat sealing, ultrasonic welding, or the like. The outer case lid120is provided with a positive external terminal121and a negative external terminal122. The energy storage apparatus10charges electricity from the outside and discharges electricity to the outside through the positive external terminal121and the negative external terminal122.

The energy storage device200is a secondary battery (battery cell) capable of charging and discharging electricity and is specifically a nonaqueous electrolyte secondary battery such as a lithium ion secondary battery. The energy storage device200has a flat rectangular parallelepiped shape (prismatic shape), and in the present embodiment, four energy storage devices200(energy storage devices201to204) are arranged side by side in the Y-axis direction. The shape, number, arrangement position, and the like of the energy storage device200are not particularly limited. The energy storage device200is not limited to the nonaqueous electrolyte secondary battery but may be a secondary battery except for the nonaqueous electrolyte secondary battery or may be a capacitor. The energy storage device200may be not a secondary battery but a primary battery that can use stored electricity without being charged by a user. The energy storage device200may be a battery using a solid electrolyte. The energy storage device200may be a laminate-type energy storage device.

Specifically, the energy storage device200includes a case210and a pair of (positive-electrode-side and negative-electrode-side) electrode terminals220. An electrode assembly, a pair of current collectors, an electrolyte solution (nonaqueous electrolyte), and the like are accommodated in the case210, but illustration thereof is omitted. The case210is a rectangular parallelepiped (prismatic) case and is formed of a metal such as stainless steel, aluminum, an aluminum alloy, iron, or a plated steel plate. The electrode terminals220are terminals (a positive terminal and a negative terminal) electrically connected to the positive electrode plate and the negative electrode plate of the electrode assembly via the current collector and are made of aluminum, an aluminum alloy, copper, a copper alloy, or the like.

The electrode assembly is an energy storage element (power generating element) formed by stacking a positive electrode plate, a negative electrode plate, and a separator. The positive electrode plate is obtained by forming a positive active material layer on a positive electrode substrate layer that is a current collecting foil made of a metal such as aluminum or an aluminum alloy. The negative electrode plate is obtained by forming a negative active material layer on a negative electrode substrate layer that is a current collecting foil made of a metal such as copper or a copper alloy. As an active material used for each of the positive active material layer and the negative active material layer, a known material can be appropriately used so long as the material can occlude and release lithium ions. The electrode assembly may be an electrode assembly in any form such as a winding-type electrode assembly formed by winding plates (a positive electrode plate and a negative electrode plate), a layering-type (stacking-type) electrode assembly formed by layering a plurality of plate-shaped electrode plates, or a bellows-type electrode assembly formed by folding plates in a bellows shape.

The current collector is a member having conductivity and rigidity (a positive electrode current collector and a negative electrode current collector) electrically connected to the electrode terminal220and the electrode assembly. The positive electrode current collector is formed of aluminum, an aluminum alloy, or the like, similarly to the positive electrode substrate layer of the positive electrode plate, and the negative electrode current collector is formed of copper, a copper alloy, or the like, similarly to the negative electrode substrate layer of the negative electrode plate. The type of the electrolyte solution is not particularly limited so long as the electrolyte solution does not impair the performance of the energy storage device200, and various electrolyte solutions can be selected.

The busbar frame300is a flat rectangular member capable of electrically insulating the busbar400from other members and regulating the positions of the busbars400. The busbar frame300is formed of an insulating member such as PC, PP, or PE, which is similar to the outer case100. Specifically, the busbar frame300is placed above the plurality of energy storage devices200and is positioned with respect to the plurality of energy storage devices200. The busbar400is placed and positioned on the busbar frame300. Thereby, the busbar400is positioned with respect to the plurality of energy storage devices200and are joined to the electrode terminals220included in the plurality of energy storage devices200(cf.FIG.4).

After the joining of the busbar400to the electrode terminals220of the energy storage devices200, the substrate500is mounted and fixed on the busbar frame300(cf.FIG.5). As described above, the busbar frame300also has a function of mounting and fixing the substrate500. The busbar frame300has a function of reinforcing the outer case100as the inner lid of the outer case100, and a function of restricting the movement of the energy storage devices200by fixation to the outer case lid120. The configuration of the busbar frame300will be described in detail later.

The busbar400is a flat-plate-like member that is disposed above the plurality of energy storage devices200and connected (joined) to the electrode terminals220of the plurality of energy storage devices200. Thus, the busbar400connects the electrode terminals220of the plurality of energy storage devices200to each other. The busbar400connects the electrode terminals220of the energy storage devices200positioned at the ends of the plurality of energy storage devices200to the positive external terminal121and the negative external terminal122.

The busbar400is formed of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or nickel, a combination thereof, or a conductive member other than the metal. In the present embodiment, the busbars400connect the positive terminal and the negative terminal of the energy storage devices200disposed adjacently to each other to connect the four energy storage devices200in series. The aspect of the connection of the energy storage devices200is not limited to the above, and series connection and parallel connection may be combined in any manner. The configuration of the busbar400will be described in detail later.

The substrate500is a circuit board that is electrically connected to the energy storage device200, monitors the charge state and the discharge state of the energy storage device200, and controls the charge and discharge of the energy storage device200. As described above, the substrate500is placed and fixed on the busbar frame300. Specifically, the substrate500includes electric components such as a fuse, a relay, a semiconductor switch such as a field-effect transistor (FET), a shunt resistor, a thermistor, and a connector.

The substrate500monitors states such as the charge state and the discharge state of the energy storage device200by acquiring information of the voltage and the like of the energy storage device200through the busbar400or acquiring the temperature information of the energy storage device200through the thermistor. The substrate500is electrically connected to the energy storage device200, the positive external terminal121, and the negative external terminal122(that is, connected to the main current path of the energy storage device200) through the busbar400to control the charge and discharge of the energy storage device200. The substrate500may only monitor the state of the energy storage device200without controlling the charge and discharge of the energy storage device200. The configuration of the substrate500will be described in detail later.

[2 Description of Configuration of Busbar Frame300, Busbar400, and Substrate500]

Next, the configurations of the busbar frame300, the busbar400, and the substrate500will be described in detail.FIG.3is a perspective view illustrating a configuration of the busbar frame300, the busbar400, and the substrate500according to the present embodiment. Specifically,FIG.3is an enlarged perspective view illustrating the busbar frame300, the busbar400, and the substrate500inFIG.2in an enlarged manner.

FIG.4is a perspective view illustrating a configuration in a state where the busbar400mounted on the busbar frame300according to the present embodiment is joined to the energy storage devices200. Specifically,FIG.4(a)is a perspective view illustrating a configuration in a state where the outer case body110, the energy storage devices200, the busbar frame300, and the busbar400illustrated inFIG.2have been assembled to each other, that is, in a state where the outer case lid120and the substrate500have been removed from the energy storage apparatus10illustrated inFIG.1.FIG.4(b)is an enlarged perspective view illustrating a protrusion442of a busbar440and an opening321formed in a wall320of the busbar frame300inFIG.4(a)in an enlarged manner.

FIG.5is a perspective view illustrating a configuration in a state where the substrate500is fixed to the busbar frame300according to the present embodiment. Specifically,FIG.5(a)is a perspective view illustrating a configuration in a state where the outer case body110, the energy storage devices200, the busbar frame300, the busbar400, and the substrate500illustrated inFIG.2have been assembled to each other, that is, in a state where the outer case lid120has been removed from the energy storage apparatus10illustrated inFIG.1.FIG.5(b)is an enlarged perspective view illustrating a state where the protrusion442of the busbar440inFIG.5(a)penetrates a through hole514of the substrate500in an enlarged manner.

[2.1 Description of Configuration of Busbar Frame300]

As illustrated inFIG.3, the busbar frame300includes a frame body310and walls320,330,340,350. The frame body310is the body of the busbar frame300and is a flat rectangular portion on which the busbar400is placed and to which the substrate500is fixed. The frame body310has an opening311for connecting the busbar400to the electrode terminal220of the energy storage device200, and a fixing portion312for fixing the substrate500.

The opening311is a rectangular through hole formed in the frame body310, and eight openings311are formed at positions facing the eight electrode terminals220of the plurality of energy storage devices200, respectively. Thereby, as illustrated inFIG.4, the busbar400(busbars410to450to be described later) can be connected (joined) to the electrode terminals220of the energy storage devices200through the openings311.

The fixing portion312is a cylindrical projection projecting in the Z-axis plus direction, and is inserted into and fixed to a through hole515formed in a substrate body510of the substrate500to be described later. In the present embodiment, four fixing portions312are inserted into and fixed to four through holes515formed in the substrate body510. Specifically, as illustrated inFIG.5, the fixing portion312is inserted into the through hole515of the substrate body510and then fixed to the substrate body510by thermal caulking. Thereby, the substrate500is fixed to the busbar frame300. A method of fixing the substrate500to the busbar frame300is not limited to thermal caulking, and any method such as screw fastening, an adhesive, welding, or the like may be used.

The walls320,330,340,350are flat and rectangular sidewalls projecting (erected) in the Z-axis plus direction from the peripheral portion of the frame body310. That is, the walls320,330,340,350are portions disposed lateral to the substrate500and covering at least a part of the side surfaces of the substrate500when the substrate500is fixed to the frame body310. The busbar frame300is an example of a lateral member covering the side surface of the substrate500. The walls320,330,340,350are provided for the purpose of guiding when the outer case lid120is disposed on the outer case body110, the purpose of restricting the movement (vibration) of the energy storage devices200in the outer case100by fixation to the outer case lid120, and some other purpose.

Specifically, the wall320is a sidewall of the frame body310on the Y-axis plus direction side and is disposed in the Y-axis plus direction of the substrate500to cover at least a part of a side surface510bof the substrate500to be described later. That is, the openings321,322are formed in the wall320, and the side surface510bof the substrate500is exposed from the openings321,322(cf.FIG.5). The openings321,322are notches penetrating in the Y-axis direction formed by recessing, in the Z-axis minus direction, the end and the center of the wall320on the X-axis minus direction side.

The wall330is a sidewall of the frame body310on the X-axis plus direction side, provided at the end thereof on the Y-axis plus direction side, and is disposed in the X-axis plus direction of the substrate500to cover at least a part of a side surface510cof the substrate500to be described later. That is, since the wall330is opened on the Y-axis minus direction side, it can be said that an opening331is provided on the wall330on the Y-axis minus direction side, and the side surface510cof the substrate500is exposed from the opening331(cf.FIG.5).

The wall340is a sidewall of the frame body310on the X-axis minus direction side, provided at the end thereof on the Y-axis plus direction side, and is disposed in the X-axis minus direction of the substrate500to cover at least a part of a side surface510d of the substrate500to be described later. That is, since the wall340is opened on the Y-axis minus direction side, it can be said that the opening341is provided on the wall340on the Y-axis minus direction side, and the side surface510d of the substrate500is exposed from the opening341(cf.FIG.5).

The wall350is a sidewall of the frame body310on the Y-axis minus direction side, is provided at the center thereof in the X-axis direction, and is disposed in the Y-axis minus direction of the substrate500to cover at least a part of a side surface510eof the substrate500to be described later. That is, since both sides of the wall350in the X-axis direction are opened, it can be said that openings351,352are provided on both sides of the wall350in the X-axis direction, and the side surface510eof the substrate500is exposed from the openings351,352(cf.FIG.5).

[2.2 Description of Configuration of Busbar400]

The busbar400includes five busbars410to450. The busbar410includes a busbar body411, a connection412, and a protrusion413. The busbar body411is the body of the busbar410and is a flat plate-like portion connected (joined) to the electrode terminal220of the energy storage devices200(specifically, the positive terminal of the energy storage device201) (cf.FIG.4). The connection412is a cylindrical portion projecting from the busbar body411in the Z-axis plus direction and is connected to another busbar (not illustrated) so as to be connected to the positive external terminal121through another busbar. The protrusion413is a protrusion projecting from the busbar body411in the Z-axis plus direction, penetrates the through hole511formed in the substrate500to be described later (cf.FIG.5), and is joined to the substrate500.

The busbar420includes a busbar body421and a protrusion422. The busbar body421is the body of the busbar420and is a flat plate-like portion connected (joined) to the electrode terminal220of the energy storage devices200(specifically, the negative terminal of the energy storage device201and the positive terminal of the energy storage device202may be used) (cf.FIG.4). The protrusion422is a protrusion projecting from the busbar body421in the Z-axis plus direction, penetrates the through hole512formed in the substrate500to be described later (cf.FIG.5), and is joined to the substrate500.

The busbar430includes a busbar body431and a protrusion432. The busbar body431is the body of the busbar430and is a flat plate-like portion that is connected (joined) to the electrode terminals220of the energy storage devices200(specifically, the negative terminal of the energy storage device202and the positive terminal of the energy storage device203may be used) (cf.FIG.4). The protrusion432is a protrusion projecting from the busbar body431in the Z-axis plus direction, penetrates the through hole513formed in the substrate500to be described later (cf.FIG.5), and is joined to the substrate500.

The busbar440includes a busbar body441and a protrusion442. The busbar body441is the body of the busbar440and is a flat plate-like portion that is connected (joined) to the electrode terminals220of the energy storage devices200(specifically, the negative terminal of the energy storage device203and the positive terminal of the energy storage device204may be used) (cf.FIG.4). The protrusion442is a protrusion projecting from the busbar body441in the Z-axis plus direction, penetrates the through hole514formed in the substrate500to be described later (cf.FIG.5), and is joined to the substrate500.

The busbar450includes a busbar body451and a connection452. The busbar body451is the body of the busbar450and is a flat plate-like portion that is connected (joined) to the electrode terminal220of the energy storage device200(specifically, the negative terminal of the energy storage device204) (cf.FIG.4). The connection452is a columnar portion projecting from the busbar body451in the Z-axis plus direction and is connected (fixed) to a connection member530of the substrate500to be described later to electrically connect the busbar450to the substrate500(cf.FIG.5).

As described above, the busbar400(busbars410to450) are sequentially connected (joined) to the electrode terminals220of the four energy storage devices200(energy storage devices201to204) to connect the four energy storage devices200in series. As a method of connecting (joining) the busbar400and the electrode terminals220of the energy storage devices200, any method may be used, like welding such as ultrasonic welding, laser welding, or resistance welding, or mechanical joining such as screw fastening or caulking joining. The busbars410to440of the busbar400has protrusions413,422,432,442penetrating the through holes511to514of the substrate500. Each of the busbars410to440as thus described is an example of a through member penetrating the through hole of the substrate500.

[2.3 Description of Configuration of Substrate500]

The substrate500includes the substrate body510, an electronic component520, and connection members530,540. The substrate body510is the body of the substrate500and is a rectangular flat-plate-like portion on which the electronic component520is mounted. In the substrate body510, a surface (upper surface) on the Z-axis plus direction side is defined as a main surface510a,a side surface on the Y-axis plus direction side is defined as a side surface510b,a side surface on the X-axis plus direction side is defined as a side surface510c,a side surface on an X-axis minus direction side is defined as a side surface510d,and a side surface on the Y-axis minus direction side is defined as a side surface510e.That is, the main surface510ais a plate surface of the substrate body510on which the electronic component520is mounted, and the side surfaces510b,510c,510d,510eare end surfaces surrounding the periphery of the substrate body510.

The through holes511to514and515penetrating the main surface510aare formed in the substrate body510. Each of the through holes511to514is an oval through hole that penetrates the substrate body510in the thickness direction (Z-axis direction) and is long in the X-axis direction. The through holes511to514are formed at positions corresponding to the protrusions413,422,432,442of the busbars410to440, respectively. Specifically, the through hole511is formed in the middle in the X-axis direction of the end of the substrate body510on the Y-axis minus direction side. The through hole512is formed at the end of the substrate body510on the Y-axis minus direction side and the X-axis minus direction side. The through hole513is formed at the end of the substrate body510on the Y-axis minus direction side and the X-axis plus direction side. The through hole514is formed at the end of the substrate body510on the Y-axis plus direction side and the X-axis minus direction side.

As described above, the protrusions413,422,432,442of the busbars410to440are inserted into the through holes511to514, respectively (cf.FIG.5), and joined by soldering or the like. Thereby, the busbars410to440and the substrate body510are electrically connected, and hence the substrate500can acquire information on the voltage and the like of the energy storage device200through the busbars410to440and the electrode terminals220of the energy storage device200. A configuration in which the protrusions of the busbars410to440are joined to the substrate500will be described in detail later.

The through holes515are circular through holes formed at four corners of both ends in the X-axis direction and both ends in the Y-axis direction of the substrate body510and penetrating the substrate body510in a thickness direction (Z-axis direction) thereof. As described above, the cylindrical fixing portion312provided in the frame body310of the busbar frame300is inserted into the through hole515. That is, four through holes515are formed at positions corresponding to the four fixing portions312, and the four fixing portions312are inserted into and joined to the four through holes515, respectively (cf.FIG.5).

The electronic component520is a circuit component mounted on the substrate body510and is a fuse, a relay, a semiconductor switch such as a field-effect transistor (FET), a shunt resistor, a thermistor, or the like. The connection member530is a member to which the connection452of the busbar450is inserted and connected (fixed). That is, as described above, the connection member530fixes the busbar450to the substrate body510to electrically connect the substrate body510and the busbar450(cf.FIG.5). The connection member540is a portion connected to the negative external terminal122via another busbar (not illustrated). That is, the connection member540fixes another busbar to the substrate body510to electrically connect the substrate body510and the negative external terminal122. The connection member530and the connection member540are electrically connected via the electronic component520and the like, whereby the busbar450and the negative external terminal122are electrically connected.

[2.4 Description of Configuration in Which Protrusion of Busbar400is Joined to Substrate500]

Next, a configuration in which the protrusions (protrusions413,422,432,442) of the busbar400(busbars410to440) are joined to the substrate500will be described in detail. Since any of the protrusions has the same configuration to be joined to the substrate500, a configuration in which the protrusion442of the busbar440is joined to the substrate500will be described below, and description of other configurations will be omitted.

FIG.6is a perspective view, a side view, and a top view illustrating a state where the protrusion442of the busbar440according to the present embodiment is joined to the substrate body510of substrate500. Specifically,FIG.6(a)is a perspective view illustrating a state before the protrusion442of the busbar440is joined to the substrate body510of the substrate500, and is a view similar toFIG.5(b).FIG.6(b)is a side view ofFIG.6(a)as viewed from the side (Y-axis plus direction), andFIG.6(c)is a top view ofFIG.6(a)as viewed from above (Z-axis plus direction).FIG.6(d)is a perspective view illustrating a state after the protrusion442of the busbar440has been joined to the substrate body510of the substrate500, and corresponds toFIG.6(a).FIG.6(e)is a side view whenFIG.6(d)is viewed from the side (Y-axis plus direction), and corresponds toFIG.6(b).FIG.6(f)is a top view whenFIG.6(d)is viewed from above (the Z-axis plus direction), and corresponds toFIG.6(c).

First, as illustrated inFIG.4(a), in a state where the busbar440is mounted on the busbar frame300and is joined to the electrode terminals220of the energy storage devices200, the protrusion442of the busbar440is disposed on the Y-axis minus direction side of the openings321formed in the wall320of the busbar frame300. Specifically, the protrusion442of the busbar440has a long side surface442aon the side surface in the Y-axis direction and a short side surface442bon a side surface in the X-axis direction. The opening321is disposed at a position facing the long side surface442a.

As illustrated inFIG.5(a)andFIGS.6(a) to6(c), when the substrate500is fixed to the busbar frame300, the protrusion442of the busbar440penetrates the through hole514of the substrate body510of the substrate500from the Z-axis minus direction. In this state, as described above, the protrusion442of the busbar440has the long side surface442aand the short side surface442bon the side surfaces in directions (Y-axis direction and X-axis direction) intersecting with a direction of penetration (Z-axis direction) into the through hole514, and the opening321is disposed to face the long side surface442a. That is, as viewed in the Z-axis direction, the rectangular protrusion442long in the X-axis direction is inserted into the oval through hole514long in the X-axis direction.

As illustrated inFIGS.6(b) and6(c), two portions of the protrusion442of the busbar440sandwiching the through hole514are referred to as a protrusion tip442cand a protrusion base end442d.That is, the protrusion tip442cand the protrusion base end442dare two portions of the protrusion442disposed on both sides of the through hole514in the Z-axis direction, in other words, on both sides of the substrate body510of the substrate500.

Specifically, the protrusion tip442cis a portion of the protrusion442on the distal end side of the protrusion442, which is disposed on the Z-axis plus direction side of the through hole514. That is, the protrusion tip442cis a portion projecting from the main surface510aof the substrate body510in the Z-axis plus direction (the outside of the substrate500). The protrusion base end442dis a portion of the protrusion442on the base end side of the protrusion442disposed on the Z-axis minus direction side of the through hole514. That is, the protrusion base end442dis a portion disposed in the Z-axis minus direction (inside the substrate500) of the substrate body510, in other words, a portion closer to the energy storage device200than the protrusion tip442c.

The opening321is disposed at a position where at least one of the protrusion tip442cand the protrusion base end442dcan be visually recognized from the outside (Y-axis plus direction). In the present embodiment, the opening321is disposed at a position where (the long side surface442aof) each of the protrusion tip442cand the protrusion base end442dcan be visually recognized from the outside. That is, the opening321is a notch which is deeply cut in the Z-axis direction, and not only the protrusion tip442cbut also the protrusion base end442d(the portion closer to the energy storage device200) is formed to be visually recognizable.

In the above configuration, as illustrated inFIGS.6(d)to6(f), the protrusion442is joined (fixed) to the substrate body510with solder600. That is, the solder600melted from the protrusion tip442cside (Z-axis plus direction side) is applied around the through hole514on the surface (main surface510a) of the substrate body510. Then, due to the action of gravity and surface tension, the solder600flows into the through hole514, and the solder600is disposed and solidified around the through hole514on a back surface of the substrate body510also on the protrusion base end442dside (Z-axis minus direction side). As a result, the protrusion tip442cis joined (fixed) to the substrate body510by the solder610, and the protrusion base end442dis joined (fixed) to the substrate body510by solder620, thus improving the joint strength of the protrusion442to the substrate500. The solder610and the solder620are solder fillets having an oval frustum shape.

As thus described, the busbar440includes the solder600(solder610and the solder620) in the state after the protrusion442has been joined to the substrate500. In this case, the solder610and the solder620become two portions of the busbar440sandwiching the through hole514, and the solder620becomes a portion closer to the energy storage device200out of the two portions.

Since the opening321is disposed at a position where both the protrusion tip442cand the protrusion base end442dare visually recognizable from the outside, the solder610and the solder620are also disposed at visually recognizable positions. That is, the opening321is formed such that the fillet state of the solder610and the solder620at the protrusion tip442cand the protrusion base end442dcan be visually recognized. In this manner, the opening321is formed such that the joined state of the protrusion442to the substrate500can be visually recognized.

That is, in the state after the protrusion442has been joined to the substrate500, the opening321is formed such that the protrusion tip442c and the protrusion base end442d, which are two portions of the busbar440sandwiching the through hole514, can be visually recognized from the outside. In the state after the protrusion442has been joined to the substrate500, the opening321is formed such that the solder610and the solder620, which are two portions of the busbar440sandwiching the through hole514, can be visually recognized from the outside. The opening321is formed such that portions of the protrusion tip442cand the protrusion base end442dexposed from the solder610and the solder620are also visible from the outside.

Similarly to the opening321, the openings331,351,352are also formed such that two portions of each of the busbars410to430, the two portions sandwiching each of the through hole511to513, can be visually recognized from the outside. That is, the opening331is formed such that two portions of the busbar410sandwiching the through hole511are visually recognizable from the X-axis plus direction. Thereby, the opening331is formed such that the joined state of the protrusion413of the busbar410to the substrate500can be visually recognized. Similarly, the openings351,352are formed such that two portions of each of the busbars420,430, the two portions sandwiching each of the through holes512,513, can be visually recognized from the Y-axis minus direction. Thereby, the openings351,352are formed such that the joined state of the protrusions422,432of the busbars420,430to the substrate500can be visually recognized.

[3 Description of Effects]

As described above, the energy storage apparatus10according to the embodiment of the present invention includes the lateral member (the busbar frame300in the present embodiment) disposed lateral to the substrate500and covering the side surface510bof the substrate500. The lateral member incudes an opening321through which at least one of two portions, sandwiching the through hole514, in the through member (the busbar440in the present embodiment) that penetrates the through hole514of the substrate500can be visually recognized from the outside. In this manner, the opening321is formed in the lateral member, and at least one of the two portions of the through member, the two portions sandwiching the through hole514of the substrate500, is made visually recognizable from the outside. Thereby, the portion penetrating the through hole514of the through member can be visually recognized from the outside of the lateral member through the opening321, so that the state of penetration of the through member into the substrate500can be easily grasped. When the state of penetration of the through member into the substrate500can be easily grasped, it is possible to prevent a defect due to attachment failure or the like of the through member to the substrate500.

The opening321of the lateral member is formed such that a portion closer to the energy storage device200out of the two portions sandwiching the through hole514in the through member can be visually recognized. In the through member, a portion closer to the energy storage device200out of two portions sandwiching the through hole514is located inside the energy storage apparatus10, and it is thus difficult to grasp a state of the through member. Accordingly, the opening321is formed in the lateral member such that the portion close to the energy storage device200can be visually recognized. As a result, the portion of the through member closer to the energy storage device200, the portion being in a state of penetration difficult to grasp, can be visually recognized from the outside of the lateral member through the opening321, so that the state of penetration of the through member can be easily grasped.

The through member is the busbar440connected to the energy storage device200, and the opening321of the lateral member is formed such that the joined state of the protrusion442, which penetrates the through hole514of the busbar440and is joined to the substrate500to the substrate500, can be visually recognized. In the present embodiment, in order to measure the voltage of the energy storage device200, the protrusion442is formed on the busbar440, and the protrusion442is allowed to penetrate the through holes514of the substrate500and is joined (e.g., soldered) to the substrate500. In this case, it is necessary to check whether the protrusion442of the busbar440is joined to the substrate500(e.g., whether a solder fillet is formed favorably). Therefore, the opening321is formed in the lateral member, and the joined state of the protrusion442to the substrate500can be visually recognized. As a result, the joined state of the protrusion442of the busbar440to the substrate500can be easily grasped, so that it is possible to prevent stress concentration on the protrusion442due to joint failure and to prevent the breakage of the protrusion442.

The lateral member is the busbar frame300on which the busbar440is placed, and the busbar frame300includes the wall320that covers the side surface510bof the substrate500and in which the opening321is formed. In the energy storage apparatus10, the busbar frame300may be provided with the wall320that covers the side surface510bof the substrate500. In the present embodiment, for the purpose of preventing the movement (vibration) of the energy storage devices200in the outer case100, or some other purpose, for example, the wall320is formed on the busbar frame300, and the busbar frame300is fixed to the outer case100by being engaged with the outer case lid120. The wall320is provided on the busbar frame300as a guide for disposing the outer case lid120on the outer case body110. In such a case, there is a possibility that the state of penetration of the through member into the substrate500cannot be grasped due to the wall320of the busbar frame300. Therefore, the opening321is formed in the wall320of the busbar frame300to make the state of penetration of the through member into the substrate500visually recognizable. As a result, even when the wall320is provided in the busbar frame300, the state of penetration of the through member into the substrate500can be easily grasped.

Since the opening321comprises a notch formed in the lateral member, by forming the notch in the lateral member, it is possible to easily form the opening321through which the state of penetration of the through member into the substrate500can be visually recognized.

The opening321is disposed to face the long side surface442aof the protrusion442of the through member. As described above, by disposing the opening321to face the long side surface442aof the protrusion442instead of the short side surface442bthereof, it is possible to visually recognize the long side surface442aside of the protrusion442instead of the short side surface442bside. This makes it easy to visually recognize the state of penetration of the through member, so that the state of penetration of the through member into the substrate500can be easily and more reliably grasped.

In the above description, the effect in the case where the busbar440is an example of the through member has been mainly described, but a similar effect is also obtained when each of the busbars410to430is an example of the through member.

[4 Description of Modified Examples]

Next, a first modification of the above embodiment will be described.FIG.7is a side view illustrating a state where the protrusion442of the busbar440according to the first modification of the present embodiment is joined to the substrate body510of the substrate500. Specifically,FIG.7is a diagram corresponding toFIG.6(e).

As illustrated inFIG.7, the busbar440in the present modification includes solder611and solder621instead of the solder610and the solder620in the above embodiment. The solder611has a shape in which the widths in the X-axis direction and the Y-axis direction sharply increase toward the Z-axis minus direction. The solder621has a shape in which the widths in the X-axis direction and the Y-axis direction sharply increase toward the Z-axis plus direction. Other configurations are the same as those of the above embodiment, and thus detailed description thereof is omitted.

As described above, according to the energy storage apparatus in the present modification, it is possible to achieve the same effects as in the above embodiment. That is, as described in the present modification, the shape of the solder600may be any shape and is not particularly limited. In general, as the shape of the solder fillet, the shape of the solder611and the solder621illustrated in the present modification is preferably used, and the effect of being able to grasp the shape by visually recognizing the shape is high.

Next, a second modification of the above embodiment will be described.FIG.8is a side view illustrating a configuration of an opening323formed in the wall320of the busbar frame300according to the second modification of the present embodiment. Specifically,FIG.8is a diagram corresponding toFIG.6(e).

As illustrated inFIG.8, in the busbar frame300according to the present modification, the opening323is formed in the wall320instead of the opening321in the above embodiment. Other configurations are the same as those of the above embodiment, and thus detailed description thereof is omitted.

The opening323is a rectangular through hole formed in the wall320and is disposed at a position facing the protrusion base end442dof the protrusion442of the busbar440and the solder620. Hence the opening323is formed such that the state of the fillet of the solder620in the protrusion base end442dcan be visually recognized. That is, the opening323is formed such that a portion closer to the energy storage device200out of two portions of the busbar440sandwiching the through hole514can be visually recognized from the outside.

As described above, according to the energy storage apparatus in the present modification, it is possible to achieve the same effects as in the above embodiment. In particular, since the opening323is a through hole formed in the lateral member (busbar frame300), by forming the through hole in the lateral member, it is possible to easily form the opening323through which the state of penetration of the through member (busbar440) into the substrate500can be visually recognized. As described above, the solder620flows from the protrusion tip442cside to the protrusion base end442dside and is solidified at the time of application, and it is thus important to visually recognize the state of the fillet of the solder620on the protrusion base end442dside so as to confirm whether the fillet of the solder620is formed favorably. Therefore, since the opening323is formed such that the state of the fillet of the solder620on the protrusion base end442dside can be visually recognized, it is possible to effectively confirm whether the fillet of the solder620is formed favorably.

Although the energy storage apparatus according to the present embodiment and the modifications thereof have been described above, the present invention is not limited to the above embodiment and the modifications thereof. That is, the embodiment disclosed herein and the modifications thereof are illustrative in all respects and are not restrictive, and the scope of the present invention is indicated by the claims, and includes all changes within the meaning and scope equivalent to the claims.

In the above embodiment and the modifications thereof, the busbar400(busbars410to440) has been an example of the through member, but any member may be used as the through member so long as the member penetrates the substrate500. Examples of the through member include a terminal (connector) of a cable connected to the substrate500, a thermistor, other electronic components, and the like.

In the above embodiment and the modifications thereof, the busbar frame300has been an example of the lateral member, but any member may be used as the lateral member so long as the member covers the side surface of the substrate500. Examples of the lateral member include the sidewall of the outer case, a binding member (side plate, end plate) for binding the plurality of energy storage devices200, a spacer, and the like.

In the above embodiment and the modifications thereof, the busbar400has been joined to the substrate500by soldering, but a method for joining the busbar400to the substrate500is not limited to soldering. The busbar400may be joined to the substrate500by welding, screw fastening, caulking, or the like. Even in this case, the joined state of the busbar400to the substrate500can be visually recognized.

In the above embodiment and the first modification, the opening321has been formed such that both of the two portions of the busbar440sandwiching the through hole514can be visually recognized. However, the opening321may be formed such that only one of the two portions can be visually recognized. In the above second modification, the opening323may be formed such that a portion farther from the energy storage device200out of the two portions of the busbar440sandwiching the through hole514can be visually recognized, or may be formed such that both of the two portions can be visually recognized. The same applies to other openings.

In the above embodiment and the modifications thereof, the opening321(323) has been disposed to face the long side surface442aof the protrusion442of the busbar440. However, the opening321(323) may be disposed to face the short side surface442bof the protrusion442. Openings may be disposed so as to be visually recognizable from two directions, such as an opening in which the same protrusion442can be visually recognized from the long side surface442aside and an opening in which the same protrusion can be visually recognized from the short side surface442bside. The same applies to other openings.

In the above embodiment and the modifications thereof, the protrusion442of the busbar440has been a rectangular portion in a top view having the long side surfaces442aand the short side surfaces442b.However, the protrusion442may be a portion having any shape such as a square shape, a circular shape, an elliptical shape, or an oval shape in a top view. When the protrusion442has an elliptical shape, an oval shape, or the like in a top view, the opening321(323) is preferably disposed at a position facing the long side surface. The same applies to the other busbars.

In the above embodiment and the modifications thereof, any of the busbars410to440may not have the above configuration, or any of the openings331,351,352,321(323) may not have the above configuration.

The scope of the present invention also includes forms constructed by arbitrarily combining the components included in the above embodiment and the modifications thereof.

The present invention can be realized not only as the energy storage apparatus as thus described but also as a lateral member (busbar frame300, etc.) having an opening such as the opening321, and can also be realized as a lateral member, the substrate500, and a through member (busbar400, etc.).

INDUSTRIAL APPLICABILITY

The present invention can be applied to an energy storage apparatus including an energy storage device such as a lithium ion secondary battery.

DESCRIPTION OF REFERENCE SIGNS

10: energy storage apparatus

200,201,202,203,204: energy storage device

310: frame body

442a:long side surface

442b:short side surface

442d:protrusion base end

510: substrate body

511,512,513,514,515: through hole