JP5142521B2 - Pack battery - Google Patents

Description

  The present invention relates to a battery pack mainly suitable for discharging a large current, and more particularly to a battery pack in which a plurality of batteries are connected in parallel and in series, and further to a battery pack optimal for an electric bicycle.

The pack battery can increase the output current by increasing the number of batteries connected in parallel, and can increase the output voltage by increasing the number of batteries connected in series. In a battery pack in which a large number of batteries are connected in series and in parallel, the unbalance of the electric characteristics of the battery increases as charging and discharging are repeated. In addition to shortening the battery life, the battery imbalance causes a decrease in the safety of the battery pack. In order to avoid this problem, a pack battery that controls charging / discharging while detecting each battery voltage has been developed. (See Patent Document 1)
JP-A-2005-317459

  As shown in FIG. 1, the battery pack of Patent Document 1 has a battery block assembly 90 and a circuit board 96 built in a case 94. In the battery block assembly 90, a large number of batteries 91 are arranged in parallel and in multiple rows and columns, and the overall shape is an elongated quadrangular prism. Further, the battery block assembly 90 has a lead plate 95 disposed on the opposite surfaces of the battery block assembly 90 as lead connection surfaces. In all the batteries 91, the end electrodes are arranged on the lead connection surface, and the lead plate 95 is connected thereto by a method such as spot welding. The lead plate 95 connects batteries 91 arranged in the vertical direction (vertical direction in the drawing) in series and connects batteries 91 arranged in the horizontal direction (horizontal direction in the drawing) in parallel. In the battery block assembly 90 of FIG. 1, four batteries 91 arranged in the horizontal direction are connected in parallel, and seven batteries 91 arranged in the vertical direction are connected in series. That is, 28 batteries 91 are connected in four rows and seven rows. Each lead plate 95 is connected to a circuit board 96 disposed on the side surface of the battery block assembly 90. The circuit board 96 is connected to the end electrodes of all the batteries 91 through the respective lead plates 95. The circuit board 96 is mounted with a voltage detection circuit that detects each battery voltage and controls charging and discharging. This battery pack can control current by detecting all battery voltages with a voltage detection circuit. For this reason, it is possible to control charging / discharging while monitoring that the battery voltage becomes unbalanced and the specific battery voltage increases, thereby improving safety and preventing deterioration of the specific battery.

However, since the circuit board 96 is disposed on the side surface of the battery block assembly 90 in the battery pack of FIG. The increase in the circuit board increases the component cost .

The present invention has been developed for the purpose of solving this drawback. An important object of the present invention, a structure capable of detecting the voltages of all the batteries, in addition to being able to safely use while protecting the battery, to provide a battery pack that can be low reducing the component costs and reduce the circuit board There is.

The battery pack of the present invention has the following configuration in order to achieve the aforementioned object.
The battery pack includes a battery block assembly 10 in which a plurality of batteries 1 are arranged in parallel and in multiple rows and columns, and is connected to each battery 1 constituting the battery block assembly 10 via a lead plate 5. A battery pack comprising a circuit board 6 provided with a voltage detection circuit for detecting each battery voltage, and an outer case 4 housing a battery block assembly 10 formed by connecting the circuit boards 6; A battery pack having all the following configurations.
(A) The battery block assembly 10 has an overall shape of an elongated quadrangular prism.
(B) The circuit board 6 is arranged in a posture facing the one end surface having the smallest area of the battery block assembly 10.
(C) The battery block assembly 10 has a plurality of series blocks 9 stacked in multiple stages in the vertical direction.
(D) Each series block 9 has a plurality of batteries 1 arranged in a two-stage stack.
(E) In the series blocks 9 arranged in a two-stage stack, the number of batteries 1 in one stage is one less than that in the other stage.
(F) The two-stage batteries 1 arranged in a stacked manner are arranged in the vertical direction of the battery block assembly 10.
(G) In the serial blocks 9 stacked in multiple stages, the end electrodes of the battery 1 are arranged on the lead connection surface 8 of the battery block assembly 10.
(H) Each battery 1 has a lead plate 5 connected to an end electrode disposed on the lead connection surface 8.
(I) The lead plate 5 has a shape that is long in the vertical direction of the battery block assembly 10, connects the two-stage batteries 1 constituting the series block 9 in series, and connects the batteries 1 of each series block 9 in parallel. Connected.
(J) On the lead connection surface 8 of the battery block assembly 10, a plurality of lead plates 5 are arranged side by side in a non-contact state.
(K) One end of each lead plate 5 is connected to the circuit board 6.

  However, in the present specification, the longitudinal direction of the elongated quadrangular prism is defined as “vertical direction”, and the direction orthogonal to the vertical direction is defined as “lateral direction”. In the figure, the vertical direction is the vertical direction, and the horizontal direction is the horizontal direction.

  In the battery pack of claim 2 of the present invention, in addition to the configuration of claim 1, each of the series blocks 9 has 5 to 9 batteries 1 arranged in a two-stage stack.

  The battery pack according to claim 3 of the present invention, in addition to the structure of claim 1, is used for a power source for supplying power to the electric bicycle 40 or the traveling motor of the electric motorcycle.

  The battery pack according to claim 4 of the present invention uses the lithium ion secondary battery as the battery 1 in addition to the structure of claim 1.

  The battery pack of the present invention is connected to a circuit board so that the voltage of all the batteries connected in series and in parallel can be detected, and can be used safely while protecting the battery. There is a feature that can be reduced and the whole can be made more compact. This feature is realized by a unique configuration of the battery arrangement of the battery block assembly and the connection state of the lead plates. In the battery pack of the present invention, the battery block assembly is formed into an elongated quadrangular prism, and a circuit board is arranged opposite to one end face, and the end electrodes of each battery are connected to the circuit board by lead plates. ing. Lead plates that connect the end electrodes of each battery to the circuit board connect the batteries in series and in parallel. In order to connect the battery and the circuit board with the lead plate in this state, the battery block assembly has a plurality of serial blocks stacked in multiple stages in the vertical direction. Each series block has a plurality of batteries arranged in a two-stage stack. Furthermore, the two-stage batteries arranged in a stack are arranged in the vertical direction of the battery block assembly. The batteries are arranged in this state, the lead plate is formed in a vertically long shape of the battery block assembly, the two-stage batteries constituting the series block are connected in series, and the batteries of each series block are connected in parallel. However, this is connected to the circuit board, and the end electrodes of each battery are connected to the circuit board.

  The above battery packs can be reduced in width, and the output current can be increased by increasing the number of batteries connected in parallel without increasing the width. This is because the circuit board is disposed at the end of the battery block assembly and serial blocks connected in parallel are stacked in the vertical direction of the battery block assembly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows.

  Further, in this specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the present specification by no means specifies the members shown in the claims to the members of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present invention unless otherwise specified, and are merely explanations. It's just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

  2 and 3 show a battery pack according to an embodiment of the present invention. FIG. 2 shows the battery block assembly housed in the exterior case, and FIG. 3 shows an exploded perspective view of the battery block assembly. The battery pack shown in these figures includes a battery block assembly 10 in which a plurality of batteries 1 are arranged in a parallel posture in a multistage multi-row, and a lead plate for each battery 1 constituting the battery block assembly 10. 5, a circuit board 6 provided with a voltage detection circuit (not shown) for detecting each battery voltage, and an outer case housing a battery block assembly 10 connecting the circuit boards 6. 4.

[Battery 1]
The battery 1 is a rechargeable cylindrical secondary battery. In the present embodiment, a cylindrical lithium ion secondary battery is used as the battery 1. Lithium ion secondary batteries are suitable as secondary batteries for pack batteries in which a plurality of lithium ion secondary batteries are connected in parallel and connected in series. This is because a plurality of lithium ion secondary batteries can be connected in parallel to reduce the internal resistance and increase the output current. In addition, since the lithium ion secondary battery has a large charge capacity, a sufficient use time can be secured without causing a shortage of capacity even in applications that require a large current. However, the battery pack of the present invention is not limited to a lithium ion secondary battery, and a secondary battery such as a nickel metal hydride battery or a nickel cadmium battery can be used as long as it is a cylindrical battery.

[Battery block assembly 10]
The battery block assembly 10 has a plurality of batteries 1 arranged in multiple rows and columns. In the illustrated battery block assembly 10, each battery 1 is arranged at a fixed position by a battery holder 2 and connected to a lead plate 5. A circuit diagram of the illustrated battery pack is shown in FIG. In the battery pack of this circuit diagram, five sets of series blocks 9 are connected in parallel by lead plates 5. Each series block 9 connects seven batteries 1 in series. Therefore, in this battery pack, 35 batteries 1 are connected in 7 series and 5 in parallel.

  The battery block assembly 10 in FIG. 2 has an overall shape of an elongated quadrangular prism, and the circuit board 6 is disposed in a posture facing the upper surface which is one end surface. The battery block assembly 10 has a plurality of series blocks 9 stacked vertically in multiple stages, and the overall shape is a quadrangular prism. The battery block assembly 10 shown in the figure has a rectangular column shape elongated in the vertical direction, which is the vertical direction in the figure, by arranging five sets of serial blocks 9 so as to be stacked vertically. The series block 9 has a plurality of batteries 1 arranged in a two-stage stack. In the illustrated series block 9, four batteries 1 are arranged on the horizontal plane on the upper stage, and three batteries 1 are arranged on the horizontal plane on the lower stage. The upper and lower batteries 1 are located in a valley between adjacent batteries 1 and are arranged in a stack. In this specification, arranging the batteries in a “stacked shape” means an arrangement in which the upper and lower batteries are arranged and stacked in the valley so that the rice brans are stacked so as not to collapse. Furthermore, as shown in FIG. 5, the series block 9 has the end electrodes of the respective batteries 1 arranged on the lead connection surface 8. As shown in FIG. 3, the batteries 1 arranged in a stack are arranged in the valley between the upper and lower batteries 1, so that they are arranged on the edge of the lead plate 5 arranged on the outermost side, on the right side in FIG. The left edge of the lead plate 5 arranged at the leftmost end of the plurality of lead plates 5 and the right edge of the lead plate 5 arranged at the rightmost end of the plurality of lead plates 5 arranged on the left side are linearized. The upper and lower series blocks 9 can be connected in parallel, and can also be connected to the circuit board 6. Further, the battery pack in which the batteries 1 are arranged in a stacked manner can reduce useless space and reduce the outer shape. This is because the battery 1 is arranged by effectively using the space formed in the valley of the cylindrical battery.

  In the illustrated serial block 9, the batteries 1 are arranged in four rows and three rows in a stacked manner, and thus one set of the serial blocks 9 connects seven batteries 1 in series. However, the battery pack of the present invention does not specify seven batteries in one series block. Although the series block is not shown, the batteries are arranged in 3 and 2 rows and 5 batteries are connected in series, or the batteries are arranged in 5 and 4 rows and 9 batteries are connected in series. You can also The series block 9 arranges the batteries 1 in a two-stage stack, but the number of the upper and lower batteries 1 is different, and one row is one less than the other. When the same number of batteries are arranged in the upper and lower stages, the battery 1 of the series block 9 can be connected in series with the long lead plate 5 of the battery block assembly 10, and the batteries 1 of the series block 9 can be connected in parallel. Because it disappears. In the illustrated battery pack, the upper battery 1 of the series block 9 is larger than the lower battery 1, but the upper and lower batteries can be reversed so that the number of the upper battery is smaller than that of the lower battery.

  The serial blocks 9 stacked vertically are connected in parallel via the lead plate 5. In the illustrated battery pack, five series blocks 9 are connected in parallel. In the battery pack of the present invention, the number of series blocks connected in parallel is not specified as five sets. It is also possible to arrange four or less series blocks vertically and connect them in parallel, or to arrange six or more series blocks vertically and connect them in parallel. However, the battery block assembly 10 has a plurality of series blocks 9 arranged vertically and connected in parallel so as to have a vertically elongated rectangular column shape. In the serial blocks 9 stacked in multiple stages, the end electrodes of the battery 1 are arranged on the lead connection surface 8 of the battery block assembly 10. This is because the lead plate 5 is connected to the batteries 1 of all the series blocks 9.

[Lead plate 5]
All the batteries 1 have the lead plate 5 connected to the end electrodes arranged on the lead connection surface 8. The lead plate 5 is made of a material having good electrical conductivity and thermal conductivity, and a metal plate such as an iron plate, nickel plate, copper plate, or aluminum plate having a surface plated with nickel or the like can be preferably used.

  The lead plate 5 has a vertically long shape of the battery block assembly 10 and connects the two stages, seven batteries 1 constituting the series block 9 in series, and the batteries 1 of each of the five sets of series blocks 9 are connected to each other. Connected in parallel. A plurality of lead plates 5 are arranged side by side in a non-connected state on the lead connection surface 8 of the battery block assembly 10, and each lead plate 5 is connected to an end electrode of the battery 1. The lead plate 5 is connected to the batteries 1 arranged in the vertical direction of the battery block assembly 10 in the vertical direction in the figure, and connects the seven batteries 1 constituting the series block 9 in series, and further arranged in the vertical direction. The connected serial blocks 9 are connected in parallel. In the illustrated battery pack, since the series block 9 arranges the four rows and three rows of batteries 1 in a stacked manner, the four lead plates 5 are arranged in a non-contact state on each lead connection surface 8. . In particular, in the battery pack shown in the figure, the four lead plates 5 are placed in the positioning recesses 24 of the battery holder 2 and placed in place. In the battery pack having this structure, the adjacent lead plates 5 can be reliably insulated and arranged.

  The upper and lower batteries 1 are arranged in a stack and are displaced in the horizontal direction. Therefore, the lead plate 5 connected to the end electrodes of the upper and lower batteries 1 is manufactured by cutting a metal plate into a zigzag shape having a predetermined width. As shown in FIG. 3, the lead plate 5 formed in a zigzag shape has a zigzag shape for each lead plate 5 along the end surface of the battery 1, so that even when an external force is applied, the load is not easily concentrated and tends to be dispersed. Therefore, the lead plate 5 is deformed more than it is broken, and the effect of absorbing the force is increased. However, the lead plate 5 arranged on one side of the lead connection surface 8, the leftmost lead plate 5 of the plurality of lead plates 5 arranged on the right side of the battery 1 in FIG. 3, and the plurality of plates arranged on the left side of the battery The rightmost lead plate 5 of the lead plate 5 connects the end electrodes serving as output terminals of the upper and lower series blocks 9 in parallel, so that the batteries 1 are connected one by one. Therefore, the lead plate 5 has a zigzag shape on one side and a linear shape on the outer edge.

  Each lead plate 5 has its upper end connected to the circuit board 6 and detects all battery voltages with a voltage detection circuit (not shown) mounted on the circuit board 6. The lead plate 5 is provided with a connecting portion 5A connected to the circuit board 6 at an end portion (upper end in the drawing). The lead plate 5 is connected to the lead pin 21 connected to the circuit board 6 by a method such as soldering, or is connected to the lead plate 20 connected to the circuit board 6 by screwing.

[Battery holder 2]
As shown in FIGS. 2 and 3, the battery holder 2 is formed by integrally connecting support side walls 12 to both ends of a holding cylinder 11 through which the battery 1 is inserted and held. The battery holder 2 is provided with a holding cylinder 11 inside the pair of supporting side walls 12 facing each other, and serves as a battery housing portion. The battery 1 is put in the holding cylinder 11, and the battery 1 is held at a fixed position. The battery holder 22 is manufactured by molding an insulating material. The insulating material forming the battery holder 2 is plastic. The holding cylinder 11 is provided through a plurality of insertion holes 13 through which the battery 1 is inserted. The battery holder 2 inserts the battery 1 into the insertion hole 13 of the holding cylinder 11 and holds the plurality of batteries 1 at predetermined positions. Since the battery holder 2 shown in the figure connects and holds 35 cylindrical batteries 1, 35 holding cylinders 11 are provided on the support side wall 12, and an insertion hole 13 is provided in each holding cylinder 11. These holding cylinders 11 are integrally formed on the support side wall 12 so that 35 batteries 1 can be arranged in the above-described arrangement, that is, in a stacked manner.

  In the battery holder 2 shown in FIG. 3, the holding cylinder 11 is divided into two in the middle in the axial direction, and is integrally formed and connected to a pair of support side walls 12. The end portion of the divided holding cylinder 11 is molded into a shape that is connected to the inside of the support side wall 12. In the battery holder 2, the battery 1 is inserted into the battery holder 2 by connecting the pair of support side walls 12 by inserting the opening 1 that is the divided end of the holding cylinder 11 into the insertion hole 13. .

  As shown in FIG. 3, the holding cylinder 11 has an insertion hole 13 opened in a cylindrical shape along substantially the entire circumference of the surface of the battery 1. However, the holding cylinder does not necessarily need to open the insertion hole in a cylindrical shape along the entire circumference of the battery. Further, the battery holder 2 shown in FIG. 3 is provided with an opening 11 </ b> A in a part of the holding cylinder 11. The illustrated battery holder 2 is provided with an opening 11A by notching the opening end of one of the divided holding cylinders 11. The battery holder 2 can detect the temperature of the battery 1 by disposing a temperature sensor 19 in an opening 11 </ b> A provided in the holding cylinder 11. This battery pack has a feature that it can control charging / discharging of the battery 1 while detecting the battery temperature with a temperature sensor. However, the holding cylinder is not necessarily provided with an opening.

  Although not shown, the holding cylinder 11 divided in the middle has an inner surface formed in a tapered shape with an inner diameter gradually decreasing from the dividing end side toward the supporting side wall 12 side. The holding cylinder 11 can hold the battery 1 in a fixed position by bringing the surface protruding from the inner surface of the end portion on the side of the support side wall 12 into surface contact with the surface of the battery 1. As described above, the structure in which the holding cylinder 11 is divided has a feature that simplifies the design of a mold for molding plastic and facilitates plastic molding.

  The pair of support side walls 12 are located at both ends of the holding cylinder 11 and are provided in parallel postures. The support side wall 12 is formed in a plate shape orthogonal to the holding cylinder 11. The pair of support side walls 12 are provided with a holding cylinder 11 at the center portion to serve as a battery storage portion, and a storage space 14 for the circuit board 6 is provided at the outer peripheral portion. The battery holder 2 has a pair of support side walls 12 protruding upward from both ends of the holding cylinder 11 in the figure, and a storage space 14 for storing the substrate holder 7 is provided between the pair of support side walls 12. . The width of the storage space 14 of the substrate is specified by the length of the holding cylinder 11, that is, the length of the battery 1, and the depth is specified by the protruding height at which the support side wall 12 protrudes upward from the holding cylinder 11. The depth of the storage space 14, that is, the protruding height of the support side wall 12 is set to a height at which the substrate holder 7 can be stored in the storage space 14.

  Further, the battery holder 2 is provided with lead plates 5 on support side walls 12 located on both sides. The support side wall 12 is connected to the end electrode exposed from the opening of the insertion hole 13 by welding the lead plate 5 outside the holding cylinder 11. The supporting side wall 12 shown in FIGS. 2 and 3 is provided with a positioning recess 24 into which the lead plate 5 is fitted on the outer surface, and the lead plate 5 is inserted into the positioning recess 24 and arranged at a fixed position. The positioning recess 24 has an outer shape slightly larger than the outer shape of the lead plate 5, and the lead plate 5 is placed here and arranged at a fixed position.

  Further, the support side wall 12 opens a connection window 18 for connecting the connection portion 5 </ b> A of the lead plate 5 to the circuit board 6. The connection window 18 is opened at the position of the connection portion 5 </ b> A of the lead plate 5 disposed in the positioning recess 24, and the connection portion 5 </ b> A is exposed to the storage space 14. The connecting portion 5 </ b> A of the lead plate 5 is disposed in the connection window 18 and is connected to the circuit board 6 of the substrate holder 7 disposed in the storage space 14.

  As shown in FIG. 3, the battery holder 2 described above is formed by integrally forming a holding cylinder 11 on a pair of support side walls 12 to form a holder unit 2A, and the holder unit 2A is connected. The pair of holder units 2A are connected to each other by screwing a set screw 23 into a boss 22 formed integrally. The holder unit 2A shown in FIGS. 2 and 3 is formed by integrally forming bosses 22 at both end portions and the central lower portion. The boss 22 is cylindrical and has a set screw 23 inserted therein. However, although not shown, the divided holder units can be connected by a locking structure, or can be connected by bonding, or can be connected in combination.

  In the battery holder 2 described above, half of the holding cylinder 11 and the supporting side wall 12 are integrally formed to form the holder unit 2A. However, the battery pack of the present invention does not specify the battery holder as described above. The battery holder can be any other structure that can hold a plurality of batteries in place. For example, the battery holder can have an integrated structure without dividing the holding cylinder and the supporting side wall, or can have a structure in which the holding cylinder and the supporting side walls at both ends are divided. As described above, the structure in which the plurality of batteries 1 are held in place by the battery holder 2 to form the battery block assembly 10 has a feature that the battery block assembly 10 can be easily and easily assembled.

[Circuit board 6]
The circuit board 6 is connected to the battery 1 via the lead plate 5. The circuit board 6 is mounted with a protection circuit (not shown) for detecting each battery voltage and protecting the battery. The protection circuit mounted on the circuit board 6 is a circuit that controls overcurrent by detecting overcharge or overdischarge of the battery 1, a circuit that detects overcharge of the battery, and cuts off the current. The protection circuit includes a voltage detection circuit (not shown) that detects the voltage of the battery 1 in order to detect overcharge or overdischarge of the battery 1. The voltage detection circuit detects each battery voltage via the lead plate 5 and detects overcharge or overdischarge of the battery 1 from the detected voltage. When any battery voltage becomes lower than the minimum voltage, the protection circuit switches off the switching element that cuts off the discharge current to cut off the discharge current. Further, when any battery voltage becomes higher than the maximum voltage, the switching element for stopping charging is switched off to stop charging. As described above, the battery pack in which the protection circuit that controls charging / discharging by detecting each battery voltage is mounted can be used safely while protecting the battery 1.

  Further, although not shown, lead wires are drawn from the circuit board 6. This lead wire has a connector connected to an external device connected to the tip. The circuit board can be connected to a connector by pulling out a communication lead wire. The connector is equipped with output terminals for the built-in battery output and connection terminals with external devices. The connector is disposed in an opening window provided in the exterior case in a state where the output terminal and the connection terminal are exposed to the outside. The battery pack is discharged in a state where the charging / discharging output terminal is connected to the electric device, and the battery is charged in a state where the charging / discharging output terminal is connected to the charger.

[Substrate holder 7]
The substrate holder 7 accommodates the circuit board 6 and arranges it at a predetermined position. The substrate holder 7 shown in FIG. 2 and FIG. 3 has a peripheral wall 26 around the bottom plate 25 and has a box shape with an upper opening. The circuit board 6 is accommodated inside the peripheral wall 26 and disposed at a predetermined position. ing. As shown in FIG. 3, the substrate holder 7 is provided with a connecting portion 28 that protrudes downward from the bottom plate 25, and a set screw 30 that penetrates the battery holder 2 is screwed into the connecting portion 28. 2 is fixed. The battery holder 2 is integrally formed with a connecting boss 29 that protrudes inside the support side wall 12 in order to screw a set screw 30 into the connecting portion 28. As shown in FIG. 3, the connecting portion 28 is disposed in a valley portion on the upper surface of the holding cylinder 11 located at the uppermost stage. The substrate holder 7 is fixed at a fixed position of the battery holder 2 by a set screw 30 passing through the connection boss 29 being screwed into the connection portion 28. However, although not shown, the substrate holder can be fixed to the battery holder with a locking structure.

  Further, the substrate holder 7 shown in FIG. 3 is provided with a support portion 27 protruding from the bottom plate 25, and the circuit board 6 is fixed to the support portion 27 via a set screw 31 so that the circuit substrate 6 is attached to the substrate holder 7. It arrange | positions in the position away from the baseplate 25. In the circuit board 6, an electronic component (not shown) that realizes a protection circuit or the like can be disposed on the surface of the substrate holder 7 that faces the bottom plate 25. As described above, the structure in which the electronic components are arranged on the surface of the substrate holder 7 facing the bottom plate 25 can effectively prevent the unevenness of these electronic components from protruding outward.

  The circuit board 6 accommodated in the board holder 7 is buried by being potted in an insulating resin, for example. By potting and embedding the circuit board 6 in an insulating resin, the circuit board 6 is waterproofed, and the lead wires 5 connected to the circuit board 6 are prevented from being separated, thereby avoiding the possibility of a short circuit. In this way, the structure in which the circuit board 6 is potted and embedded in the insulating resin can protect the circuit board 6 with a waterproof structure, so that the failure of the circuit board 6 is extremely reduced, and the battery 1 is mounted on the circuit board 6 over a long period of time. There is a feature that can be charged and discharged while protecting. The circuit board 6 shown in FIG. 3 has a through hole 6 </ b> A at the center so that an insulating resin can be filled between the circuit board 6 and the bottom plate 25 of the board holder 7. Resin such as urethane resin, silicon resin, and epoxy resin can be used as the potting material.

[Exterior case 4]
The exterior case 4 is not shown in detail, but is formed of, for example, ABS resin, and is divided into two or more members and fixed by being connected by a connection method such as screwing or fitting. The exterior case 4 can be designed in various shapes according to the use, purpose, and usage of the battery pack. As shown by the chain line in FIG. 2, the exterior case 4 can be easily carried by providing a handle 4 </ b> A integrally formed on the upper part.

  As described above, a plurality of batteries 1 are held at a predetermined position by the battery holder 2 to form the battery block assembly 10, and the lead plate 5 connected to the end face of each battery 1 is connected to the circuit board 6, Further, the substrate holder 7 to which the circuit board 6 is fixed is fixed to the battery holder 2 to form a battery core pack. The battery core pack is housed in the outer case 4 to form a battery pack.

  Furthermore, the battery pack of the present invention can be housed in an exterior case as a waterproof structure by storing the battery core pack in a waterproof bag and watertightly closing the opening. As this waterproof bag, for example, a flexible sheet formed into a bag shape can be used. A plastic sheet can be used as the flexible sheet of the waterproof bag. For the plastic sheet, polyimide (PI), polyethylene imide (PEI), pet (PET) or the like can be used. In this battery pack, the battery core pack in which the circuit board is connected to the battery is housed in a waterproof bag, so that the circuit board can be housed in the outer case together with the battery in addition to the battery. Furthermore, this battery pack can be used as a cushioning material while waterproofing the core pack of the battery with a waterproof bag to absorb the impact of the outer case and improve the impact resistance strength.

  The battery pack of the present invention can be used as a power source for driving the motor of the electric bicycle 40, for example, as shown in FIG. The battery pack shown in the figure is mounted on the back surface of a vertical pipe 41 provided under a saddle 42 of the electric bicycle 40. As described above, the battery pack attached along the vertical pipe 41 of the electric bicycle 40 protrudes in the lateral direction or rearward as the width increases, and cannot be disposed in a balanced manner. In particular, it cannot be stably mounted along the vertical pipe 41 in a vertical position. The battery pack of the present invention has a unique configuration in the arrangement of the batteries 1 in the battery block assembly 10 and the connection state of the lead plates 5 while connecting a large number of batteries to a predetermined output voltage. The circuit board 6 can be arranged on the upper part of the elongated rectangular columnar battery block assembly 10 to make the battery pack compact without increasing the width of the whole battery pack. Therefore, as a power source for an electric bicycle, it can be used in an ideal state as a battery pack attached to the vertical pipe 41 in a vertical posture. However, it goes without saying that the battery pack of the present invention can be used as a power source for electric devices other than electric bicycles. In particular, the battery pack of the present invention is suitably used for applications that require a large output current by increasing the number of batteries connected in parallel, while reducing the width of the battery pack to a compact shape as an elongated rectangular column. it can.

  The battery pack of the present invention is suitably used as a power source for electric equipment used outdoors, particularly electric bicycles and electric motorcycles.

It is a cross-sectional view of a conventional battery pack. It is a perspective view of the battery block aggregate | assembly of the battery pack concerning one Example of this invention. It is a disassembled perspective view of a battery block assembly. 1 is a circuit diagram of a battery pack according to an embodiment of the present invention. It is a schematic sectional drawing which shows the state which connects a lead board to the lead connection surface of the battery which comprises a battery block aggregate | assembly. It is a side view which shows the usage example of the battery pack concerning one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery 2 ... Battery holder 2A ... Holder unit 4 ... Exterior case 4A ... Handle 5 ... Lead board 5A ... Connection part 6 ... Circuit board 6A ... Through-hole 7 ... Board holder 8 ... Lead connection surface 9 ... Series block 10 ... Battery Block assembly 11 ... Holding cylinder 11A ... Opening 12 ... Support side wall 13 ... Insertion hole 14 ... Storage space 18 ... Connection window 19 ... Temperature sensor 20 ... Lead plate 21 ... Lead pin 22 ... Boss 23 ... Set screw 24 ... Positioning recess 25 ... Bottom plate 26 ... Peripheral wall 27 ... Supporting portion 28 ... Connecting portion 29 ... Connecting boss 30 ... Set screw 31 ... Set screw 40 ... Electric bicycle 41 ... Vertical pipe 42 ... Saddle 90 ... Battery block assembly 91 ... Battery 94 ... Case 95 ... Lead plate 96 ... Circuit board

Claims (4)

A battery block assembly (10) in which a plurality of batteries (1) are arranged in a multi-stage multi-row in a parallel posture;
A circuit board (6) having a voltage detection circuit connected to each battery (1) constituting the battery block assembly (10) via a lead plate (5) and detecting each battery voltage, and a circuit A battery pack comprising an outer case (4) housing a battery block assembly (10) formed by connecting substrates (6), and having all the following configurations.
(A) The battery block assembly (10) has an elongated quadrangular prism shape as a whole.
(B) The circuit board (6) is arranged in a posture facing the one end surface having the smallest area of the battery block assembly (10).
(C) The battery block assembly (10) has a plurality of series blocks (9) stacked in multiple stages in the vertical direction.
(D) Each series block (9) has a plurality of batteries (1) arranged in a two-stage stack.
(E) In the series blocks (9) arranged in a two-stage stack, the number of batteries (1) in one stage is one less than that in the other stage.
(F) The two-stage batteries (1) arranged in a stack are arranged in the vertical direction of the battery block assembly (10).
(G) In the series block (9) stacked in multiple stages, the end electrodes of the battery (1) are arranged on the lead connection surface (8) of the battery block assembly (10).
(H) Each battery (1) has a lead plate (5) connected to an end electrode disposed on the lead connection surface (8).
(I) The lead plate (5) has a shape that is long in the vertical direction of the battery block assembly (10), connects the two-stage batteries (1) constituting the series block (9) in series, and each series The battery (1) of the block (9) is connected in parallel.
(J) On the lead connection surface (8) of the battery block assembly (10), a plurality of lead plates (5) are arranged side by side in a non-contact state.
(K) One end of each lead plate (5) is connected to the circuit board (6).   The battery pack according to claim 1, wherein each series block (9) has 5 to 9 batteries (1) arranged in a two-stage stack.   The battery pack according to claim 1, wherein the battery pack is for a power source for supplying electric power to a traveling motor of an electric bicycle (40) or an electric motorcycle. The battery pack according to claim 1, wherein the battery (1) is a lithium ion secondary battery.

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