JP2020205135A - Pack cell - Google Patents

Abstract

To surely prevent harmful effects resulting from an extraneous material immersing into a case from an open hole, while maintaining a function for draining water and gas from inside of the outer case by opening the open hole, becoming the exhaust port, in the outer case receiving a cell.SOLUTION: A battery pack includes a cell 1 capable of charging and discharging, and an outer case 4 internally receiving the cell 1, where the outer case 4 has an open hole 6 communicating with the inside of the outer case 4. In the outer case 4, a closed chamber 5 is provided oppositely to the open hole 6, by opening the open hole 6 side and closing the surroundings. An extraneous material immersing into the outer case 4 from the open hole 6 is retained in the closed chamber 5 and movement in the outer case 4 is prevented.SELECTED DRAWING: Figure 4

Description

The present invention relates to a battery pack in which a battery is housed in an outer case, and more particularly to a battery pack in which a through hole such as a drain hole or an exhaust hole is opened in the outer case.

A battery pack containing a plurality of rechargeable and dischargeable batteries in an outer case is used as a power source for various battery-powered battery devices, both indoors and outdoors. This type of battery pack is used as a drain hole for draining water that has inadvertently entered the outer case, or for exhausting the air inside the outer case or the gas discharged from the battery to the outside. As an exhaust hole of, there is one having a through hole in the outer case. (See Patent Documents 1 and 2)

Japanese Unexamined Patent Publication No. 2013-192282 Japanese Unexamined Patent Publication No. 2006-196277

As described above, the battery pack having a through hole in the outer case as a discharge port for discharging the water and gas in the outer case to the outside allows the water and the gas inside the outer case to be discharged from the discharge port. It has the characteristic that safety can be guaranteed by discharging it to the outside. However, in the battery pack having the discharge port opened in the outer case in this way, foreign matter may enter from the outside through this discharge port. If the invading foreign matter has conductivity, it moves inside the outer case after the invasion, and when this foreign matter comes into contact with the energized parts such as the battery, lead plate, and substrate stored in the outer case, the battery is released. There is a risk of short circuit and smoke or fire.

The present invention has been made in view of such a background in the prior art, and one of the purposes thereof is to open a through hole serving as a discharge port in an outer case for storing a battery and to open a through hole as an outlet from the inside of the outer case. It is an object of the present invention to provide a battery pack capable of surely preventing harmful effects caused by foreign matter entering the inside of the case through the through hole while maintaining the function of discharging water, gas and the like.

Means for Solving Problems and Effects of Invention

A battery pack according to an embodiment of the present invention includes a battery 1 that can be charged and discharged and an outer case 4 that houses the battery 1 inside, and the outer case 4 has a through hole 6 that is communicated with the inside of the outer case 4. The outer case 4 is provided with a closing chamber 5 that faces the through hole 6 and opens the through hole 6 side to close the periphery, and enters the outer case 4 through the through hole 6. The foreign matter is retained inside the closed chamber 5 to prevent the foreign matter from moving inside the outer case 4.

With the above configuration, by opening a through hole in the outer case that houses the battery, the water that has entered the outer case and the gas in the outer case can pass through the through hole and be discharged to the outside. Inside the case, a closing chamber whose surroundings are closed and the through hole side is opened is provided so as to face the through hole, so that foreign matter entering the outer case through the through hole is retained inside the closing chamber. It is possible to prevent the battery from moving inside the outer case and protect the batteries stored in the outer case from harmful effects caused by invading foreign matter.

The battery pack of the present invention further includes a battery holder 2 for arranging the battery 1 in a fixed position, and a closed chamber 5 can be formed in the battery holder 2.
With the above configuration, the batteries stored in the outer case are placed in place by the battery holder, and a closed chamber is formed in the battery holder, so that the closed chamber can be easily and easily and space-saving inside the outer case. Can be placed.

The battery pack of the present invention includes a battery storage unit 20 in which the battery 1 is a cylindrical battery and the battery holder 2 holds a plurality of cylindrical batteries in a posture parallel to each other. Further, the battery holder 2 is a battery storage unit 20. A semi-cylindrical curved plate portion 21 along the outer peripheral surface of the cylindrical battery is provided at the bottom of the battery, and a closing chamber 5 is provided in a valley portion 26 formed on the outer surface between the curved plate portions 21 adjacent to each other. Can be formed.
With the above configuration, it is possible to efficiently form a closed chamber with a depth by effectively utilizing the valley portion formed on the outside of the curved plate portion constituting the battery storage portion. In particular, this closed chamber can allow foreign matter that invades the inside to fall into the valley along the outer surface of the curved plate portion and reliably stay at the bottom of the closed chamber.

In the battery pack of the present invention, the closing chamber 5 includes a peripheral wall 50 formed by closing all sides and a bottom plate portion 54 formed by closing the bottom surface, and the opening area of the opening on the through hole 6 side is set to the through hole 6. It can be made wider than the opening area of.
With the above configuration, foreign matter that has passed through the through hole of the outer case and has entered the inside can be reliably guided to the inside of the closed chamber.

In the battery pack of the present invention, the opening area of the through hole 6 can be 1 cm ² or less, and the opening area of the opening of the closed chamber 5 can be 3 cm ² or less.
With the above configuration, it is possible to reliably guide the foreign matter that has passed through the through hole to the inside of the closed chamber while limiting the size of the foreign matter that enters the inside of the outer case.

In the battery pack of the present invention, the closing chamber 5 includes a peripheral wall 50 having all four sides closed and a bottom plate portion 54 having the bottom surface closed so that the front end surface of the peripheral wall 50 approaches the inner surface of the exterior case 4. Can be done.
With the above configuration, by bringing the tip surface of the peripheral wall that closes all four sides of the closed chamber close to the inner surface of the outer case, it is possible to reliably prevent foreign matter that has entered the closed chamber from moving to the outside of the closed chamber.

The battery pack of the present invention can have a deep bottom portion 55 in which the closed chamber 5 is formed by partially deeply forming the bottom plate portion 54.
With the above configuration, the foreign matter that has entered the closed chamber can be retained in the deep bottom portion, and the foreign matter that has entered the closed chamber can be reliably prevented from moving to the outside of the closed chamber.

It is a perspective view of the battery pack which concerns on embodiment of this invention. FIG. 2 is a sectional view taken along line II-II of the battery pack shown in FIG. FIG. 3 is a sectional view taken along line III-III of the battery pack shown in FIG. It is an exploded perspective view of the battery pack shown in FIG. It is an enlarged perspective view of the closed chamber provided in the battery holder of the battery pack shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and are not specified as follows. It should be noted that the members shown in the claims are by no means specified as the members of the embodiment. Unless otherwise specified, the dimensions, materials, shapes, relative arrangements, etc. of the constituent members described in the embodiments are not intended to limit the scope of the present invention to that alone, but merely described. It's just an example. The size and positional relationship of the members shown in each drawing may be exaggerated to clarify the explanation. Further, in the following description, members of the same or the same quality are shown with the same name and reference numeral, and detailed description thereof will be omitted as appropriate. Further, each element constituting the present invention may be configured such that a plurality of elements are composed of the same member and the plurality of elements are combined with one member, or conversely, the function of one member is performed by the plurality of members. It can also be shared and realized. In addition, the contents described in some examples and embodiments can be used in other embodiments and embodiments. Furthermore, in the specification, the vertical direction shall be specified in the drawings.

The battery pack of the present invention can be used as a power source for electric devices mainly used indoors and outdoors, such as cleaners, lighting devices, digital cameras, and video cameras. However, the present invention does not specify the use of the battery pack, and as a power source for power, for example, an electric motor driven by a motor such as an electric tool, an electric assist bicycle, an electric bike, an electric wheelchair, an electric three-wheeled vehicle, or an electric cart. It can also be used as a power source for equipment.

The battery pack 100 shown in the perspective view of FIG. 1, the cross-sectional views of FIGS. 2 and 3, and the exploded perspective view of FIG. 4 has a plurality of batteries 1 that can be charged and discharged, and these batteries 1 are placed in a fixed position inside. It is provided with an exterior case 4 for storing. In the battery pack 100 shown in the figure, a plurality of batteries 1 are arranged at fixed positions via a battery holder 2, and positive and negative electrode terminals of these batteries 1 are connected by a lead plate 3 to form a battery core pack 9. This core pack 9 is stored inside the outer case 4. In this specification, the vertical direction and the horizontal direction are defined as the directions shown in FIG. Further, the longitudinal direction of the battery is defined as the longitudinal direction.

(Battery 1)
In the battery pack 100 shown in the figure, the battery 1 is a cylindrical battery. In a cylindrical battery, an electrode body is housed in a cylindrical outer can, filled with an electrolytic solution, and the opening of the outer can is sealed with a sealing plate. In the cylindrical battery, the bottom surface of the outer can, which is both end faces, and the convex electrode provided at the center of the sealing plate are positive and negative electrode terminals. In the battery pack shown in the figure, the battery 1 is a cylindrical battery, but the present invention does not specify the battery as a cylindrical battery, and for example, a square battery can be used. The battery is a non-aqueous electrolyte secondary battery such as a lithium ion battery. However, the present invention does not specify the battery as a lithium ion battery, and all secondary batteries currently used and will be developed, such as other non-aqueous electrolyte secondary batteries and nickel-metal hydride batteries, can be used.

(Battery holder 2)
The plurality of batteries 1 are arranged at fixed positions via the battery holder 2. As shown in FIGS. 2 and 3, the battery holder 2 includes a plurality of rows of battery storage units 20 for setting a plurality of batteries 1 in a fixed position. Since the battery pack 100 of FIG. 2 arranges cylindrical batteries in four rows, the battery holder 2 is provided with groove-shaped battery storage portions 20 formed in parallel to each other in four rows. In the battery holder 2, cylindrical batteries are arranged in the battery storage portions 20 of each row, and four cylindrical batteries are arranged in a posture parallel to each other.

The battery storage portion 20 of the battery holder 2 is formed in a groove shape so that a cylindrical battery can be set in a fixed position. The battery holder 2 shown in FIG. 2 is composed of a semi-cylindrical curved plate portion 21 having a curved surface along the outer peripheral surface of the cylindrical battery at the bottom of the battery storage portion 20, and between the batteries 1 adjacent to each other. A partition wall 22 is provided to isolate adjacent batteries 1 from each other. The partition wall 22 extends downward from the side edge of the curved plate portion 21, and the partition walls 22 facing each other are connected to each other by the connecting portion 23 between the adjacent batteries 1. The battery holder 2 of FIG. 2 forms a connecting groove 24 for inserting a connecting ridge 44 protruding from the bottom surface of the first case 4A, which is the exterior case 4, between the lower ends of the facing partition walls 22. The battery holder 2 is connected to a fixed position of the first case 4A by inserting a connecting ridge 44 into a connecting groove 24 formed between the partition walls 22, and also isolates adjacent batteries 1 from each other to cause thermal runaway. Is being prevented.

Further, in the battery holder 2, both ends of the battery storage portions 20 in a plurality of rows are closed by end face walls 25. The end face wall 25 is opened with electrode windows (not shown) that expose the electrode terminals at both ends of the battery 1 housed in the battery storage section 20. The electrode window is made smaller than the outer shape of the battery 1 so that the battery 1 does not pass through. In the plurality of batteries 1 arranged in a posture parallel to the battery holder 2, the electrode terminals provided on both end surfaces are arranged on the same plane, and the electrode terminals exposed from the electrode windows on both sides of the battery holder 2 are lead plates. It is connected via 3.

The battery holder 2 is formed into a predetermined shape by a resin such as a thermoplastic resin which is an insulating material. The battery holder 2 can preferably be made of a resin having excellent flame retardancy. As such a resin, for example, PC (polycarbonate) or PP (polypropylene) can be used.

In the above battery holder 2, a plurality of batteries 1 are arranged side by side in a posture parallel to each other on the same plane. However, the battery holder is not necessarily limited to a structure in which a plurality of batteries are arranged in a plane parallel to each other, but a structure in which a plurality of batteries are arranged in a multi-stage multi-row structure in a posture parallel to each other. You can also do it. A battery holder in which a plurality of batteries are arranged in multiple stages and rows is not shown, but has a shape in which a plurality of cylindrical batteries are arranged in a bale state, or a shape in which the cylindrical batteries are arranged vertically and horizontally at the intersections of a grid pattern. Can be. A battery holder in which a plurality of cylindrical batteries are arranged in a bale state can arrange a large number of cylindrical batteries in a space-efficient manner, and the whole can be made compact. These battery holders can also be used as holding portions by providing a partition wall along the outer peripheral surface of the batteries between the cylindrical batteries arranged in multiple stages and rows.

(Lead plate 3)
The lead plate 3 is fixed to the electrode terminals of the battery 1 exposed from the electrode window of the end face wall 25 by spot welding or the like on both end faces of the battery holder 2. The lead plate 3 is made of a thin metal plate having excellent conductivity. The lead plate 3 is connected to the electrode terminals of a plurality of batteries 1 housed in the battery holder 2, and these batteries 1 are connected in series and in parallel.

(Core pack 9)
In the battery pack 100 shown in FIGS. 2 to 4, four batteries 1 are housed in the battery holder 2 to form a battery block 10, and two sets of battery blocks 10 are connected in the length direction of the battery 1. It constitutes a battery core pack 9. In the battery block 10 shown in the figure, two adjacent batteries 1 are connected in parallel to form two sets of parallel units 11. Further, two sets of battery blocks 10 are connected at opposite end faces, four sets of parallel units 11 are connected in series by a lead plate 3, and eight batteries 1 are connected in four series and two in parallel. In this core pack 9, two batteries 1 are connected in parallel to increase the output current, and four sets of parallel units 11 are connected in series to increase the output voltage. Thereby, for example, when a lithium ion secondary battery of 3.6 V per cell is used as the battery 1, four batteries 1 can be connected in series to obtain an output of 14.4 V.

(Insulation sheet 17)
Further, in the battery pack 100 shown in the figure, insulating sheets 17 are attached to both end surfaces of the core pack 9 so that the lead plate 3 does not cause an unintended short circuit. For the insulating sheet 17, paper or a plastic film having excellent insulating properties can be used. The insulating sheet 17 shown in the figure has an outer shape along the end face of the battery holder 2 so as to cover the entire lead plate 3 connected to the end face of the battery holder 2.

(Exterior case 4)
The outer case 4 houses a battery core pack 9 in which a plurality of batteries 1 are arranged at fixed positions of the battery holder 2. The exterior case 4 shown in FIGS. 1 to 4 is divided into a first case 4A and a second case 4B, and a storage portion for storing the core pack 9 is formed inside. The outer case 4 is also formed into a predetermined shape by a resin such as a thermoplastic resin which is an insulating material. The outer case 4 can also be preferably made of a resin having excellent flame retardancy, and is made of, for example, PC (polycarbonate) or PP (polypropylene).

In the first case 4A, the outer peripheral wall 41 is connected around the bottom plate to form a box shape with an upper opening. The first case 4A in the figure is provided with an outer peripheral wall 41 so as to have an inner shape and a depth that can accommodate the lower portion of the battery core pack 9. Further, as shown in FIGS. 2 and 4, the first case 4A has a bottom surface of a plurality of rows of connecting ridges 44 extending in the length direction of the battery 1 at positions facing the partition wall 22 of the battery holder 2 to be housed. It is provided so as to project upward from. Since the battery holder 2 shown in FIG. 2 is provided with three rows of connecting grooves 24 between the four rows of battery storage portions 20, the first case 4A is provided with three rows of connecting ridges 44 on each side. ing.

Further, the first case 4A shown in FIGS. 3 and 4 is located between the battery blocks 10 arranged on the left and right, and is located in the region between the connecting ridges 44 formed on the left and right, and has a plurality of compartments. The walls 43 are provided apart in the front-rear direction. In the first case 4A shown in the figure, four partition walls 43 are provided in a straight line. Each partition wall 43 is inserted between the left and right battery blocks 10 to isolate and protect the connection portion of the lead plate 3 connected to the opposing batteries 1.

The second case 4B has a box shape with a lower opening by connecting an outer peripheral wall 45 around the top plate so that the upper opening of the box-shaped first case 4A can be closed. The second case 4B in the figure is provided with an outer peripheral wall 45 so as to have an inner shape and a depth that can accommodate the upper portion of the core pack 9 housed in the first case 4A.

As shown in FIGS. 2 to 4, the above exterior cases 4 are connected to each other in a state where the battery core pack 9 is housed between the first case 4A and the second case 4B. In the first case 4A and the second case 4B, the outer peripheral walls 41 and 45 facing each other are connected to each other, and the core pack 9 is arranged inside. The exterior case 4 is connected by ultrasonically welding or adhering the end faces of the outer peripheral walls 41 and 45 provided in the first case 4A and the second case 4B. Although not shown, the first case and the second case can also be connected by screwing a set screw penetrating one case into a boss provided in the other case.

(Through hole 6)
Further, the exterior case 4 shown in FIGS. 1 to 4 is provided with a through hole 6 communicating with the inside of the second case 4A. The through hole 6 is opened as a discharge port for discharging water that has entered the outer case 4 and gas in the outer case 4 to the outside. As described above, the structure in which the through hole 6 serving as the discharge port is provided in the outer case 4 is used as a drain hole for discharging the moisture that has entered the inside of the outer case 4 to the outside, or the gas in the outer case 4 For example, it is used as a ventilation hole for exhausting hot air trapped in the outer case 4 due to heat generated by the battery 1 and gas discharged from the battery 1 to the outside.

In the second case 4B shown in FIGS. 2 and 4, the rear portion 47 is formed higher than the front portion 46 in the figure, in other words, the inside of the rear portion 47 is formed deeper than the inside of the front portion 46. An inclined portion 48 is provided at the boundary between the front portion 46 and the rear portion 47, and a through hole 6 is opened in the inclined portion 48. As described above, the structure in which the through hole 6 is opened in the inclined portion 48 has a feature that it can effectively prevent foreign matter from entering the inside through the through hole 6. This is because the foreign matter that falls on the upper surface of the outer case 4 falls along the inclined portion 48, so that the foreign matter is less likely to enter the through hole as compared with the structure in which the through hole is opened in the horizontal plane. However, the through hole can also be opened in the horizontal plane of the front portion and the rear portion.

The opening area of the through hole 6 opened in the outer case 4 is, for example, smaller than 1 cm ² and preferably smaller than 0.5 cm ² . By limiting the opening area of the through hole 6 in this way, it is possible to limit the foreign matter that has passed through the through hole 6 and has entered the inside of the outer case 4. However, if the opening area of the through hole 6 is too small, there is a risk of clogging due to dust or the like. Therefore, the opening area of the through hole 6 is larger than 5 mm ² , preferably larger than 10 mm ² . The through hole 6 shown in the figure has a square or rectangular internal shape in a plan view. The through hole having this shape can effectively prevent clogging due to dust or the like while reducing the opening area. However, the through hole may have a circular shape, an elliptical shape, or a slit shape in the plan view.

As described above, the battery pack 100 in which the outer case 4 is provided with the through hole 6 as a discharge port allows the moisture and the gas in the outer case 4 to pass through the through hole 6 to the outside. It has the characteristic of being able to be discharged. However, in this battery pack, there is a risk that foreign matter may enter the inside of the outer case 4 through the through hole 6 opened in the outer case 4. In the battery pack of the present invention, a closing chamber 5 is provided inside the outer case 4 at a position facing the through hole 6 in order to prevent harmful effects caused by foreign matter entering the inside through the through hole 6 of the outer case 4. ing.

(Closed room 5)
As shown in the cross-sectional views of FIGS. 2 and 3 and the enlarged perspective view of FIG. 5, the closed chamber 5 has a structure in which the through hole 6 side is opened to close the periphery, and the through hole 6 to the outer case 4 are formed. Foreign matter that invades the inside is retained inside the closed chamber 5 and prevented from moving inside the outer case 4. The battery pack 100 shown in the figure is provided with a closing chamber 5 facing a through hole 6 opened in the outer case 4 integrally molded into a plastic battery holder 2. With this structure, the closed chamber 5 can be easily, easily, and efficiently arranged at a position facing the through hole 6 inside the exterior case 4. However, the closed chamber does not necessarily have to be integrally molded with the battery holder, and may be provided as a separate member from the battery holder, or may be integrally molded with the first case, which is an exterior case.

The closed chamber 5 formed in the battery holder 4 is a surface opposite to the surface provided with the battery storage portion 20, and is a battery holder 2 facing the through hole 6 opened in the second case 4B of the outer case 4. It is formed on the outer surface of the battery. The closed chamber 5 shown in the figure is formed on the upper surface of the battery holder 2, and the closed chamber 5 is arranged in a fixed position with the core pack 9 housed between the first case 4A and the second case 4B. The through hole 6 opened in the outer case 4 is located in the upper opening of the outer case 4.

The closed chamber 5 is formed in a shape having a closed space having an upper opening formed by opening the through hole 6 side by closing the peripheral surface with the peripheral wall 50 and the bottom surface with the bottom plate portion 54. The peripheral wall 50 that closes the periphery of the closed chamber 5 connects the side walls 51 formed on both the left and right sides, the rear wall 52 formed rearward, and the front wall 53 formed forward to each other, and has four sides. It forms a closed space. These peripheral walls 50 are formed so that the front end surface approaches the inner surface of the outer case 4, and narrows the gap formed between the peripheral wall 50 and the outer case 4. As a result, foreign matter that has entered the closed chamber 5 is prevented from moving to the outside of the closed chamber 5. As shown in FIGS. 2 and 3, the upper opening of the closed chamber 5 is arranged so that the through hole 6 opened in the outer case 4 is located inside the opening in a plan view. Further, the opening area of the opening of the closed chamber 5 is wider than the opening area of the through hole 6, so that foreign matter that has passed through the through hole 6 and invades the inside can be reliably guided to the inside of the closed chamber 5. I have to. The opening area of the upper opening of the closed chamber 5 can be, for example, 3 cm ² or less.

Further, as shown in FIG. 2, the bottom surface of the closed chamber 5 is a connecting portion 23 that connects the curved plate portion 21 forming the bottom portion of the battery storage portion 20 and the measuring edge of the curved plate portion 21 between the adjacent batteries 1. It is composed of and. The battery holder 2 shown in FIGS. 2 and 5 is an outer surface of a semi-cylindrical curved plate portion 21 forming a battery housing portion 20 on the inner side surface, and is formed between the curved plate portions 21 adjacent to each other. A closed chamber 5 is formed in the valley portion 26. In this structure, a deep closed chamber 5 can be formed by effectively utilizing the valley portion 26 formed on the outside of the curved plate portion 21 forming the battery storage portion 20 along the outer peripheral surface of the cylindrical battery. it can. That is, the closed chamber 5 can be provided with a deep bottom portion 55 formed by partially deeply forming the bottom plate portion 54 by effectively utilizing the valley portion 26. The closed chamber 5 having this shape guides foreign matter that has entered the inside of the closed chamber 5 through the through hole 6 to the deepest portion 55 and stays in this portion so that it can move inside the outer case 4. You can definitely stop it. In particular, by guiding the foreign matter to the deepest portion 55 formed at the valley portion of the curved plate portion 21, the adverse effect of the foreign matter can be prevented most effectively. However, the closed chamber does not necessarily have to be provided in the region including the valley portion of the curved plate portion, and the bottom surface of the closed chamber may be a flat surface, or may be an inclined surface or a curved surface.

As described above, the peripheral wall 50 of the closed chamber 5 formed on the upper surface of the battery holder 2 is also used as a support convex portion for arranging the battery holder 2 housed in the outer case 4 at a fixed position in the outer case 4. Can be done. In particular, by arranging the upper end in a state of being close to the inner surface of the outer case 4, the battery holder 2 housed in the outer case 4 can be arranged at a fixed position while being specified.

(Circuit board 7)
Further, in the battery pack 100 of FIGS. 2 and 4, the circuit board 7 is housed in the outer case 4 in addition to the battery core pack 9. The battery pack 100 in the figure is provided with a storage space 28 for arranging the circuit board 7 on the upper surface side of the battery holder 2. The battery holder 2 shown in the figure is provided with a plurality of support convex portions 27 projecting upward, and the circuit board 7 can be housed between the upper surface of the curved plate portion 21 of the battery holder 2 and the inner surface of the second case 4B. Space is provided as a storage space 28. In the exterior case 4 shown in FIG. 2, the rear portion 47 is formed higher than the front portion 46, and a storage space 28 is formed inside the rear portion 47 to accommodate the circuit board 7. In particular, in the battery pack 100 shown in FIG. 4, the circuit board 7 is arranged with the region on the right rear side as the substrate storage area, and the through hole 6 is opened on the left front side of the exterior case 4. The structure in which the circuit board 7 and the through hole 6 are arranged at diagonal positions of the exterior case 4 having a substantially rectangular shape in a plan view is a circuit board caused by foreign matter or moisture entering through the through hole 6. There is a feature that the harmful effect on 7 can be effectively prevented.

The circuit board 7 can mount electronic components such as a protection circuit. The protection circuit may include a detection circuit that detects the voltage, remaining capacity, temperature, etc. of each cylindrical battery, and a switching element that is switched on and off by the data of the battery 1 detected by the detection circuit. Further, in the battery pack 100 in which the circuit board 7 is housed, the output connector 19 connected to the circuit board 7 is pulled out from the outer case 4 via the lead wire 18. The output connector 19 has an output terminal and a signal terminal, is charged and discharged via the output terminal, and can communicate with a device set via the signal terminal. However, the battery pack may have a structure in which connection terminals consisting of output terminals and signal terminals are fixed to the circuit board without providing an output connector, and these connection terminals are exposed from the outer case for external connection. it can.

The present invention can be effectively used for a battery pack having a through hole for discharging in an outer case for storing the battery.

100 ... Battery pack 1 ... Battery 2 ... Battery holder 3 ... Lead plate 4 ... Exterior case 4A ... First case 4B ... Second case 5 ... Closed chamber 6 ... Through hole 7 ... Circuit board 9 ... Core pack 10 ... Battery block 11 ... Parallel unit 17 ... Insulation sheet 18 ... Lead wire 19 ... Output connector 20 ... Battery storage part 21 ... Curved plate part 22 ... Partition 23 ... Connecting part 24 ... Connecting groove 25 ... End face wall 26 ... Valley part 27 ... Supporting convex part 28 ... Storage space 41 ... Outer wall 43 ... Partition wall 44 ... Connecting ridge 45 ... Outer wall 46 ... Front 47 ... Rear 48 ... Inclined 50 ... Peripheral wall 51 ... Side wall 52 ... Rear wall 53 ... Front wall 54 ... Bottom plate 55 ... Deep bottom

Claims (7)

Batteries that can be charged and discharged and
It is equipped with an outer case for storing the battery inside.
The outer case has a through hole communicated with the inside of the outer case.
The inside of the outer case is provided with a closing chamber facing the through hole and opening the through hole side to close the periphery.
A battery pack characterized in that foreign matter that enters the outer case through the through hole is retained inside the closed chamber to prevent movement in the outer case. The battery pack according to claim 1, further
It is equipped with a battery holder that places the battery in place.
A battery pack in which the closed chamber is formed in the battery holder. The battery pack according to claim 2.
The battery is a cylindrical battery, and the battery holder includes a battery storage unit that holds a plurality of the cylindrical batteries in a posture parallel to each other.
The battery holder is provided at the bottom of the battery housing portion with a semi-cylindrical curved plate portion along the outer peripheral surface of the cylindrical battery, and is formed on the outer surface between the curved plate portions adjacent to each other. A battery pack in which the closed chamber is formed in a valley portion. The battery pack according to any one of claims 1 to 3.
The closed chamber is provided with a peripheral wall that is closed on all sides and a bottom plate that is closed on the bottom surface.
A battery pack in which the opening area of the opening on the through hole side is made wider than the opening area of the through hole. The battery pack according to claim 4.
A battery pack in which the opening area of the through hole is 1 cm ² or less and the opening area of the closed chamber is 3 cm ² or less. The battery pack according to any one of claims 1 to 5.
The closed chamber is provided with a peripheral wall that is closed on all sides and a bottom plate that is closed on the bottom surface.
A battery pack in which the tip surface of the peripheral wall approaches the inner surface of the outer case. The battery pack according to any one of claims 1 to 6.
The closed chamber is a battery pack having a deep bottom portion formed by partially deepening the bottom plate portion.

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