JP4744096B2 - 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.

  The battery pack 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. Since the battery pack with this structure incorporates a large number of batteries, it is important to have a structure that allows each battery to be connected efficiently. As a battery pack for realizing this, a battery pack in which the battery is connected with a lead plate having a unique structure has been developed (see, for example, Patent Document 1). Also, in battery packs used in applications requiring high output, such as bicycles, tools, automobiles, etc., there is a structure in which a plurality of batteries are connected in parallel and further connected in series to increase the output. Can take.

  Such battery packs tend to increase the number of batteries used due to demands for higher output and higher current. When the number of built-in batteries increases, the shape of the battery pack becomes longer in one direction. If the battery pack becomes too long in a certain direction, the balance of connection with the battery-driven electric device that is used with the battery pack attached becomes poor. For this reason, it is necessary to devise the arrangement of a large number of batteries so that the outer shape of the battery pack has a well-balanced size in the vertical and horizontal directions, rather than having a biased shape that is long only in one direction. On the other hand, when a battery pack is designed exclusively for each electric device, the design cost is increased and the efficiency is lowered. Therefore, it is desired to have a certain degree of versatility in design. For this reason, it is conceivable that a predetermined number of batteries can be combined into a block shape and arranged so that the required number of battery blocks are connected to each other so that a desired output can be adjusted and versatility in configuration can be obtained.

However, when a battery block including a large number of batteries is stacked, connection between the battery and a circuit board including a battery charge / discharge circuit becomes a problem. That is, since electrodes are generally arranged on the end faces of each battery, it is necessary to make electrical connection between the battery and the circuit board so that the end faces of adjacent batteries are not short-circuited unexpectedly. In order to prevent a short circuit, the end face of the battery is insulated, but depending on the battery used, it is necessary to detect the intermediate potential of the battery block assembly. Terminal must be provided, and the prevention of short circuit at this part must also be considered. On the other hand, in a structure in which a plurality of battery blocks are stacked, when the number of stacked battery blocks is increased, the distance between the substrate and the battery block is increased, and it is necessary to connect between them with a lead plate or a bus bar. The longer the lead plate and the like, the higher the probability of occurrence of a short circuit, so that a sufficient insulation structure is required. Thus, in a battery pack using a plurality of batteries, a structure that improves workability such as wiring while ensuring insulation has been desired.
JP-A-10-308205

  The present invention has been made in view of such problems. A main object of the present invention is to provide a battery pack with improved reliability by reliably insulating the end faces of the batteries when the battery blocks are stacked and connected.

To achieve the above object, the battery pack of the present invention includes: a battery including an end face to a plurality of end, the lead plate for holding a plurality of batteries together by fixing the end face of the battery in a substantially parallel state, adjacent A circuit in which a plurality of battery blocks each having an insulating spacer partitioning between the batteries and an electronic circuit that is arranged at the edge of the battery block assembly connecting the plurality of battery blocks and wired to the batteries is mounted A voltage that is electrically connected to each lead plate to draw out the potential of the lead plate of each battery block to the voltage take-out surface, with the substrate and one surface on the end face side of the battery in the battery block assembly as a voltage take-out surface The battery pack assembly and the circuit board are accommodated in a state in which the battery cell assembly and the circuit board are electrically connected to each other. The battery pack, the battery block facing at least the voltage-extracting surface, the end surface facing the at least one of the voltage-extraction surface is provided with an insulating sheet that overturn the upper surface of the lead plate, the other on the upper surface of the insulating sheet by arranging the voltage extraction portion connected to the battery blocks, it performs insulation between the voltage pickup section and the at least the voltage extraction surface and facing the battery end faces provided with lead plates of the battery block. Thereby, the battery can be arranged in a block shape by concentrating the voltage extraction surface where the potential of each battery block is concentrated on one side, and connecting the voltage extraction surface and the circuit board, and further, the end surface of the battery block By covering with an insulating sheet, the voltage extraction part that connects the battery and the circuit board is securely insulated from the end face of the battery block so as to prevent short circuit even if a large number of batteries are arranged in blocks. A highly safe battery pack can be configured, and a battery pack with a good balance can be obtained without making the shape long and narrow in one direction.

  Another battery pack of the present invention includes a terminal for electrically connecting a lead plate of the battery block located on the voltage extraction surface among the plurality of battery blocks constituting the battery block assembly to the circuit board. A lead protrusion is provided, an insulating sheet is disposed on the lead protrusion, and a lead plate of the next battery block adjacent to the battery block is further placed on the voltage extraction surface by the voltage extraction unit on the insulating sheet. The same structure is repeated until the lead plates of all the battery blocks are individually pulled out to the voltage extraction surface by the voltage extraction unit. As a result, the potentials of all the battery blocks can be taken out to one of the battery block aggregates, that is, the voltage take-out surface, and at the same time, the voltage take-out part of the adjacent battery block is sandwiched between the insulating sheets and reliably insulated. , Can increase the safety of the battery.

  Furthermore, the other battery pack of the present invention insulates the battery blocks by bending the insulating sheet and inserting one piece of the bent insulating sheet between adjacent battery blocks. Thus, the insulating sheet can be used not only for the insulation of the battery end face but also for the insulation spacer between the battery blocks, and the insulation structure can be simplified.

Furthermore, in another battery pack of the present invention, the shape of the insulating sheet is U-shaped in cross section, and both end surfaces of the battery block are covered with U-shaped opposing surfaces. Thereby, both end surfaces of the battery block can be covered with a single insulating sheet to insulate the end surfaces, and the battery blocks can be insulated from each other.
The

  Furthermore, in another battery pack of the present invention, the shape of the insulating sheet is L-shaped and covers one end face of the battery block. Thereby, one insulation sheet can insulate one side of a battery block, and can also insulate battery blocks.

  Furthermore, according to another battery pack of the present invention, batteries facing one end face of the battery block assembly are arranged so as to have the same potential for each column of the battery block assembly, and further extended in the column direction. Each battery is electrically connected by a potential extracting unit. As a result, by making one side of the battery the same potential for each row, insulation on one side can be made unnecessary, and there is no need to superimpose an insulating sheet, contributing to thinning and miniaturization, and suppressing manufacturing costs. it can. Furthermore, since the electrical connection between the battery and the circuit board can be concentrated on one side, work such as welding can be performed on only one side, and there is an advantage that workability can be improved and productivity can be improved.

Furthermore, in the other battery pack of the present invention, the circuit board is disposed on the surface opposite to the lead protruding portion and the voltage extracting portion drawn out to the voltage extracting surface, and the lead protruding portion and the voltage extracting portion and the circuit board are arranged. Are electrically connected by lead wires. As a result, the voltage extraction surface side from which the terminal for extracting battery voltage is drawn out and the substrate side are separated from each other, so that an inadvertent short circuit can be avoided and the lead wire can securely connect the circuit board. By doing so, the reliability by short circuit prevention can be improved.
Furthermore, in another battery pack of the present invention, the battery is cylindrical.

  According to the battery pack of the present invention, even if the battery pack uses a large number of batteries, these batteries are not arranged so as to be elongated only in one direction, but can be arranged in a well-balanced block shape. It can be set as a shape suitable for attachment with an electric equipment. In addition to the configuration in which the battery pack of the present invention is configured by laminating a plurality of batteries in a block shape, the end face of the battery is covered with an insulating sheet, and the voltage extraction portion that electrically connects the battery and the circuit board is short-circuited with the end face of the battery This is because the situation is surely prevented. Thus, even in a configuration in which a plurality of battery blocks are stacked and a terminal is provided on the battery end face in order to measure the intermediate potential of the battery block assembly, a battery pack with high safety by preventing a short circuit between the battery blocks can be obtained. can do.

  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, 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 is 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.

1 to 3 show a battery block assembly built in a battery pack according to an embodiment of the present invention. In these drawings, FIG. 1 is a perspective view of the battery block assembly 201, FIG. 2 is a perspective view of FIG. 1 viewed from the back, and FIG. A battery block assembly 201 shown in these drawings is obtained by stacking battery blocks 200A and 200B in two stages. In each battery block 200, five batteries 210 are arranged horizontally, and a total of ten batteries 210 are arranged substantially in parallel at equal intervals so as to form two stages vertically. The battery block 200 includes a spacer 220 so that each battery 210 is in a predetermined arrangement.
[Spacer 220]

The spacer 220 forms a battery holding part 222 that is open to hold the side surface of the cylindrical battery 210. The battery holding part 222 has a cylindrical shape along the curved surface of the battery so that the curved surface of the side surface of the cylindrical battery 210 can be securely held. The cross section may be a polygonal shape such as a substantially hexagonal honeycomb type. Alternatively, the cross section of the spacer may be divided into a space in which each battery 210 is arranged by combining a plurality of plate-like portions into a shape in which a plurality of crosses are continuous. Or the spacer surface does not necessarily need to be planar, and the surface may be uneven. In addition, if a member that elastically deforms is used for the spacer, the curved surface of the battery can be pinched and securely held. The spacer 220 is made of an insulating member, and is formed by integrally molding, for example, hard or soft plastic, or a paper sheet is folded and combined. The spacer 220 divides the battery holding portion 222 so that the plurality of batteries 210 can be arranged while being accurately positioned, and each battery 210 can be separated independently. When a plurality of batteries are brought close to each other without a spacer, there is a problem that other batteries are affected by friction between the batteries or heat generation of the batteries. For example, when an abnormal heat is generated due to a short circuit of one battery, the adjacent battery may be damaged by the heat. These effects can be reduced by isolating each battery 210 with the spacer 220. In addition, when a member having a good thermal conductivity such as a metal is used for a part or all of the spacer, it is possible to promote the heat dissipation of the heated battery and prevent the battery life from decreasing. In this example, the batteries 210 are arranged so as to cross in a cross shape, but by changing the shape of the spacers, the centers of the batteries can be arranged so as to be offset vertically. In particular, when a cylindrical battery is used, a large number of batteries can be arranged in a space-efficient manner by arranging them in an offset shape.
[Battery 210]

  The battery 210 of the battery block 200 is a rechargeable secondary battery. In the battery pack of FIGS. 1 to 3, the battery 210 is a cylindrical battery. However, the battery 210 can be a square battery or a thin battery. In this embodiment, a cylindrical lithium ion battery is used as the battery 210. Lithium ion batteries are suitable as secondary batteries for pack batteries in which a plurality of lithium ion batteries are connected in parallel and connected in series. This is because a plurality of lithium ion batteries can be connected in parallel to reduce the internal resistance and increase the output current. In addition, since the lithium ion battery has a large charge capacity, a sufficient use time can be ensured without causing a shortage of capacity even in applications requiring a large current. However, the battery pack of the present invention does not specify the battery 210 as a lithium ion battery, and a secondary battery such as a nickel-hydrogen battery or a nickel-cadmium battery can also be used. The number and arrangement of the batteries 210, and the connection form can be changed as appropriate. In the example of FIGS. 1 to 3, each battery block 200 connects two batteries 210 in parallel and five sets are connected in series, but is not limited to this example.

  In addition, a thermal element is provided in the vicinity of the battery 210 in order to detect the temperature of the battery 210 and control battery protection. As the thermosensitive element, an element such as a thermistor, a thermocouple, or a PTC element that changes electrical characteristics according to temperature can be used. The thermal element, which is a thermistor, is located in the valley between the cylindrical batteries 210, so that the temperature of two batteries can be measured with one thermal element, and the space for arranging the thermal element using the space between the valleys. Can earn.

Furthermore, the battery block 200 is fixed with a double-sided tape or the like. The battery block 200 is fixed by winding the periphery of the battery block 200 with a fixing tape such as a double-sided tape so that the side surface portion of the battery 210 is attached. Thereby, the battery 210 is securely fixed so as not to be detached from the spacer 220.
[Lead plate 240]

Further, a lead plate 240 is fixed to the end face of each battery 210. The lead plate 240 covers the end surfaces of the plurality of batteries 210 at a flat portion and electrically connects the terminals of the batteries 210 to connect the batteries 210 in series and in parallel. The lead plate 240 is made of a material having good electrical and thermal conductivity, and a metal plate such as aluminum, copper, or silver can be suitably used. In the example shown in the perspective view of FIG. 1 and the rear view of FIG. 3A, two lead plates 240A for connecting the four batteries 210 adjacent in the vertical and horizontal directions and the small battery for connecting the two batteries 210 arranged in the vertical direction are used. The lead plate 240B is electrically connected to one sheet. The lead plate 240 electrically connects the end faces of the batteries 210 and connects the batteries 210 in series or in parallel. Furthermore, the lead plate 240 functions as a terminal for measuring the intermediate potential of the battery block assembly 201. For this reason, the lead plate 240 is preferably partially protruded and perforated to facilitate connection of a lead wire or the like. The lead wire 500 electrically connects the battery 210 and the circuit board 600 as will be described later. In addition, the lead plate 240 can be provided with a heat dissipation function of the battery 210.
[Voltage extraction unit 246]

  Furthermore, the lead plate 240 includes a voltage extraction unit 246. The voltage extraction unit 246 functions as a lead for extracting the potential of each battery block 200 to the voltage extraction surface 248. In the example of FIGS. 1 to 3, the battery blocks 200 </ b> A, B are vertically stacked and stacked in two stages. Among these, in the battery block 200 </ b> A facing the voltage extraction surface 248, the lead protrusion 242 that protrudes a part of the lead plate 240 is protruded toward the voltage extraction surface 248. The lead protrusion 242 is preferably formed integrally with the lead plate 240. However, the lead protrusion may be a separate member from the lead plate, and these may be joined by welding or the like.

  Furthermore, the battery block 200B laminated on the opposite side of the voltage extraction surface 248 with respect to the battery block 200A has a configuration substantially similar to that of the battery block 200A, and the battery 210 is connected by the lead plate 240. In order to draw out the potential of the lead plate 240 of the battery block 200B to the voltage extraction surface 248, the lead plate 240 is connected to the voltage extraction portion 246. The voltage extracting portion 246 is also preferably integrally formed with the lead plate 240. However, the voltage extraction part may be a separate member from the lead plate, and these may be joined by welding or the like. As described above, only the battery block 200 positioned on the voltage extraction surface 248 includes the lead protrusions 242 on the lead plate 240, and the subsequent battery blocks 200 include the voltage extraction portions 246 instead of the lead protrusions 242 on the lead plate 240. I have. In other words, each of the voltage extraction portion 246 and the lead protrusion 242 is adjusted to an appropriate length and shape according to the position of the battery block 200 as a part of the lead plate 240.

The voltage extraction unit 246 is extended by the height of the battery block 200A so as to draw a terminal from the battery block 200B to the voltage extraction surface 248. At this time, the voltage extraction unit 246 is disposed so as to be separated from the lead plate 240 of the battery block 200A so that the voltage extraction unit 246 does not contact the lead plate 240 of the battery block 200A. Here, a step portion is provided at the joint surface between the lead plate 240 and the voltage extraction portion 246 of the voltage block B, and the voltage extraction portion 246 extends to the voltage extraction surface 248 so as to straddle the lead plate 240. In addition, an insulating sheet 249 is disposed between the voltage extraction unit 246 and the lead plate 240 of the battery block 200A to reliably insulate them. For this reason, the height difference between the lead plate 240 and the voltage extraction portion 246 of the voltage block B, that is, the height of the stepped portion is made substantially equal to the thickness of the insulating sheet 249.
[Insulation sheet 249]

The end face of the battery block 200 is covered with an insulating sheet 249 so that the voltage extraction portion 246 extended to the voltage extraction surface 248 does not cause a short circuit. As shown in FIGS. 1 and 3A, the insulating sheet 249 is formed in a rectangular shape having a size that substantially covers the end surface of the battery block 200A (the back surface in FIG. 3A). The insulating sheet 249 is made of a material having excellent insulating properties, such as paper or a plastic sheet.
[L-shaped insulating sheet 249]

Further, as shown in the side view of FIG. 3 (d), the insulating sheet 249 can be insulated into an L shape to insulate between the battery block 200A and the battery block 200B. The L-shaped insulating sheet 249 is designed to have a size that covers the end face of the battery 210 and a size that can cover the bottom surface of the battery block 200, and can be formed by bending a single sheet. It goes without saying that the battery blocks 200 can be stacked in three or more stages in the same manner. As shown in FIG. 4, even when the battery blocks 200 are stacked in three stages, by using the insulating sheet 249 </ b> A having a size to be covered with each battery block 200, the end face of the battery 210 and the space between the battery blocks 200 are similarly connected. Can be covered and insulated. Since the insulating sheet has a simple configuration in which the insulating sheet member is simply bent, it can be manufactured inexpensively and easily. In addition, by using both insulation between battery blocks and insulation of the battery end face with a single insulating sheet, the number of parts can be reduced and the manufacturing process can be simplified.
[Same Potential Extraction Unit 247]

As described above, the potential of the lead plate 240 is drawn to the voltage extraction surface 248 by insulating the voltage extraction portion 246 with the insulating sheet 249 on one end surface of the battery block 200. On the other hand, as shown in FIGS. 2 and 3C, the other end surface of the battery block 200 is all drawn out to the voltage extraction surface 248 by the same potential extraction portion 247 in the vertical direction of the battery block assembly 201. This is because all the potentials of the batteries 210 positioned in the vertical direction are designed and arranged in advance so as to have the same potential. Thereby, all the end surfaces of the battery 210 positioned in the vertical direction can be connected and taken out by one sheet of the same potential take-out portion 247, and the connection process and configuration can be facilitated. In addition, since the potentials are the same in the vertical direction, there is no possibility of a short circuit in this portion, and it is not necessary to perform the above and below insulation. For this reason, the insulating sheet 249 can be made unnecessary.
[U-shaped insulation sheet 249]

  Or as another embodiment of this invention, an insulating sheet can also be comprised so that both surfaces of the end surface of the battery block 200 may be covered. As shown in FIG. 5, the cross section of the insulating sheet 249 </ b> B is bent at two locations so as to have a U-shape that opens upward, and covers both end surfaces and the bottom surface of the battery block 200. The size and the bending position of the insulating sheet 249B are specifically designed for each battery block 200 according to the area to be covered with the end face. Since this structure covers both end faces of the battery and insulates these parts, a short circuit can be prevented more reliably. Moreover, since it is not necessary to make one end surface of a battery into the same electric potential, the freedom degree of a battery arrangement | positioning and a connection form increases.

Moreover, it can also be set as the structure which uses two L-shaped insulation sheets instead of said U-shaped insulation sheet 249B. That is, two L-shaped insulating sheets 249C as shown in FIG. 6 may be stacked in the opposite direction so as to cover the left and right end surfaces. Further, at this time, the L-shaped insulating sheet 249C is covered so as to cover the half area of the bottom of the battery block 200 so as to reduce the overlapping area when the two L-shaped insulating sheets 249C insulate the battery blocks 200 from each other. One piece may be formed small. Thereby, by combining the two L-shaped insulating sheets 249C, it is possible to insulate the battery blocks 200, and it is possible to avoid an increase in the thickness between the battery blocks 200 by reducing overlapping portions. Alternatively, as shown in FIG. 7, the joining surfaces of the two L-shaped insulating sheets 249D are brought into close contact with each other so that the overlapping portion is eliminated, or the battery block is formed with the two L-shaped insulating sheets 249D so as to be slightly spaced from each other. You may comprise so that between 200 may be coat | covered. Also in this configuration, since the battery blocks 200 are separated by the thickness of the insulating sheet 249D, conduction between them can be prevented.
[Wiring with lead wire 500]

As described above, after the potential of the lead plate 240 is drawn out to the voltage extraction surface 248 of the battery block assembly 201, the voltage extraction surface 248 and the circuit board 600 are electrically connected. A lead wire 500 is used for electrical connection between the voltage extraction surface 248 and the circuit board 600. 8 to 9 show a state in which the voltage extraction surface 248 and the circuit board 600 are wired with the lead wires 500. FIG. In these drawings, FIG. 8 is a perspective view of the battery block assembly 201 as seen from the substrate side, and FIG. 9 is a perspective view of the voltage extraction surface 248 as seen from the reverse side. As shown in these drawings, each voltage extraction portion 246 drawn to the voltage extraction surface 248 is wired to the circuit board 600 by a lead wire 500. The circuit board 600 includes a drive circuit that controls charging / discharging of the battery 210, and the power supply line of the battery block assembly 201 is drawn by the lead wire 500. At the same time, the circuit board 600 detects the battery voltage and the battery temperature, and is mounted with battery components constituting a protection circuit and the like for protecting them. The circuit board 600 detects the voltage of the voltage extracting unit 246 to detect the both ends of each battery block 200. Is detected as an intermediate voltage of the battery block assembly 201. Each lead wire 500 is connected to a predetermined position of the circuit board 600 with solder or the like. As shown in FIGS. 8 to 9, the lead wires 500 are wired substantially parallel to each other so that the lead wires 500 do not cross each other. Furthermore, the lead wire 500 is covered with a vinyl tube or the like, so that insulation is maintained. The thickness, material, etc. of the lead wire 500 are also selected according to the voltage value and the like. For example, the lead wire 500 that pulls out the power supply line is a thick type with high reliability that can withstand a large current and high voltage. For the same reason, it is desirable to use a thicker type of lead plate and lead protrusion for those used for the power supply line.
[Inner case 400]

  The battery block aggregate 201 is preferably housed in the inner case 400. 10 and 11 show a state where the voltage extraction surface 248 and the substrate are wired by the lead wire 500 in a state where the battery block assembly 201 is housed in the inner case 400. FIG. As shown in this figure, by housing the battery block aggregate 201 in the inner case 400, the battery block 200 can be protected to improve impact resistance and insulation can be improved. The inner case 400 shown in the drawing is divided into an upper case and a lower case, and is fixed by welding or screwing in a state where the battery block assembly 201 is housed therein.

  10 and 11, when the battery block assembly 201 is inserted into the lower inner case 402, it is inserted into the lead slit 410 formed in the lower outer case 102. In the lower inner case 402, a lead slit 410 having a size capable of inserting the lead protrusion 242 is opened in advance at a portion where the lead protrusion 242 is located. Thus, the battery block 200 is positioned in the lower inner case 402 by inserting the lead protrusion 242 into the lead slit 410.

When the lead protrusion 242 is inserted into the lead slit 410, the lead protrusion 242 passes through the lower inner case 402 and protrudes to the outside of the inner case 400. In this state, one end of the lead wire 500 is wired in the wiring hole opened in the lead protrusion 242. The other end of the lead wire 500 is wired to the circuit board 600. Thus, wiring is performed on each lead plate 240 in order to measure the terminal voltage of the battery 210. In particular, when a lithium ion battery is used, it is necessary to detect the battery voltage in order to protect the battery 210 and to monitor the voltage across the battery block 200, which is an intermediate voltage of the battery block assembly 201. For this reason, the voltage of each lead plate 240 can be detected and the terminal voltage of a predetermined battery block 200 can be monitored.
[Sealing rib 412]

  Further, a sealing rib 412 is provided around the lead slit 410 as shown in FIG. FIG. 11 shows the lower inner case 402 as viewed from the bottom. As shown in this figure, sealing ribs 412 that stand upright in a direction substantially parallel to the direction in which the lead protrusions 242 protrude are formed so as to surround the periphery of the lead slit 410. The sealing rib 412 forms a section for sealing in a state where the lead wire 500 is wired to the lead protrusion 242. Sealing is performed by injecting a sealing material such as a silicon-based resin into a region surrounded by the sealing rib 412, thereby fixing the lead plate 240 and the lead wire 500 in a state where they are securely electrically connected. At the same time, waterproofing is also achieved. Furthermore, insulation and heat dissipation can be improved. The sealing rib 412 is provided on the surface of the lower inner case 402 by integral molding. As shown in FIG. 11, the sealing rib 412 is formed in the same plane as the side surface so as to extend from the side surface of the lower inner case 402, and further, a lead wire holding portion 414 is formed in a U shape. Yes. As a result, the lead wire 500 is pulled out linearly from the circuit board 600 without being bent, and the lead wire 500 is sandwiched and held by the lead holding portion, thereby enabling stable wiring. The height of the sealing rib 412 may not be uniform over the entire circumference, and only a part of the wall surfaces may be formed high. In particular, the sealing rib 412 facing the side surface of the inner case 400 is designed to be higher than the upper end of the lead protrusion 242 in a state where the lead protrusion 242 is inserted into the lead slit 410. This prevents the projecting lead projecting portion 242 from coming into contact with a conductive member such as metal and causing a short circuit. In particular, since a part of the lead protrusion 242 is not exposed after sealing, the possibility of a short circuit at this part can be avoided. Further, since the conductive lead protrusion 242 does not protrude even before sealing, it is difficult to cause a short circuit even when contacting the metal plate during ultrasonic welding.

  The inner case 400 is divided into upper and lower parts, and includes a box-like lower inner case 402 having an opening and a lid-like upper inner case 401. After the assembled battery block assembly 201 is inserted into the lower inner case 402 with the upper opening, the opening is closed with the upper inner case 401, and this portion is hermetically sealed by thermal welding or bonding such as ultrasonic welding. Fixed. The inner case 400 is manufactured by molding an insulating material. The insulating material forming the inner case 400 is a plastic that can be ultrasonically welded, that is, a thermoplastic plastic. The inner case 400 is preferably a translucent member. As the light-transmitting member, a polycarbonate resin can be suitably used. The polycarbonate resin is excellent in heat resistance and is not dissolved in the electrolytic solution, and thus is suitable for protecting a lithium ion battery. By using the translucent inner case, the state inside the inner case can be visually recognized from the outside, so that it is easy to visually detect defects in the battery and problems in assembly, and the reliability of the battery can be improved. On the other hand, the outer case 100 and the like can be made of an inexpensive ABS resin or the like, and the manufacturing cost of the battery pack can be reduced.

  In addition, although the example which uses an inner case was demonstrated in said example, it is good also as a structure which accommodates a battery block directly in an exterior case, without using an inner case as above-mentioned. The storage case in the claims corresponds to an inner case or an outer case.

Further, in the above example, a configuration is adopted in which the voltage extraction portion 246 drawn from the lead plate 240 and the substrate are disposed on the opposite side of the battery block assembly 201 and are electrically connected via the lead wire 500. This clearly separates the battery potential extraction position and the wiring from the substrate, and prevents shorting between adjacent lead plates and the substrate. However, the voltage extraction surface and the arrangement surface of the circuit board can be the same surface. By making these the same surface, the wiring by the lead wire becomes unnecessary, and the lead plate and the voltage extracting part can be directly connected to the circuit board, and the circuit configuration can be simplified. On the other hand, since the terminals are adjacent to each other, a sufficient insulating structure is required. Even in such a structure, the voltage take-out portions are insulated with the above-described insulating sheet, and one surface of the battery block assembly is set to the same potential, so that the possibility of occurrence of a short-circuit accident is greatly reduced. A high battery pack can be constructed.
[Circuit board 600]

  A circuit board 600 that mounts electronic components and the like, constitutes a battery charge control, a protection circuit, and the like, and constitutes an arithmetic circuit for the remaining capacity of the battery is held by a board holder 610. FIG. 10 is a perspective view showing a state where the circuit board 600 is fixed on the inner case 400. As shown in this figure, the substrate holder 610 has substrate holder ribs 612 upright so as to surround the circuit substrate 600. In general, since the circuit board is thin with respect to the thickness and has a large area, the circuit board is weakened in strength. However, by surrounding the periphery in a frame shape with the substrate holder 610, the board holder rib 612 extended to a plane orthogonal to the plane. The effect of being reinforced with is obtained.

The circuit board 600 is arranged in parallel with the battery block 200 so that the wiring by the lead wire 500 can be made short and simple. The protection circuit mounted on the circuit board 600 is a circuit that detects battery overcharge or overdischarge and controls current, a circuit that detects battery overcharge and interrupts current, and the like. The protection circuit includes a voltage detection circuit (not shown) that detects the voltage of the battery in order to detect battery overcharge and overdischarge. The voltage detection circuit detects the voltage of the battery block 200 as an intermediate voltage of the battery block assembly 201 via the lead plate 240, and detects battery overcharge or overdischarge from the detected voltage. Furthermore, although not shown, the circuit board is connected to an output terminal for charging and discharging. 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.
[Potting]

The circuit board 600 wired in the board holder 610 is waterproofed by potting or coating with a resin 620 as shown in FIG. By potting the circuit board 600, the circuit board 600 is waterproofed, and separation of the lead wires 500 wired from the circuit board 600 is prevented, thereby avoiding the possibility of short circuit. As a potting material, a resin 620 such as a urethane resin, a silicon resin, or an epoxy resin can be used. Potting improves heat dissipation. In the state without any coating, it will be exposed to air with high heat insulation, and thermal conductivity is poor, but since heat is radiated from the contact area by coating, the heat dissipation is improved and the reliability of the battery pack is also improved Be improved. Further, as described above, a silicon-based resin is preferable as a potting material because it can improve heat dissipation.
[Exterior case 100]

  The battery block assembly 201 wired as described above is stored in the outer case 100. An example of the outer case 100 is shown in the perspective view of FIG. 12 and FIG. 13 which is a perspective view seen from the opposite side of FIG. The outer case 100 is molded of ABS resin or the like, divided into two or more members, and fixed by a connecting method such as screwing or fitting. The exterior case 100 can be designed in various shapes according to the use, purpose, and usage of the battery pack. The exterior case 100 shown in these drawings is divided into an upper exterior case 101 and a lower exterior case 102.

  With the above configuration, even if the batteries are stacked in a block shape, they can be wired to the circuit board while preventing a short circuit, so according to the number of batteries, without having an unbalanced arrangement that is simply connected long in one direction. The number of vertical and horizontal lengths can be adjusted as appropriate. As a result, as shown in FIGS. 4 and 5, a battery pack having a shape close to a square can be configured, and a battery pack having a shape that is easy to handle and can be easily designed as a mounting surface with an electric device to which the battery pack is connected. can do. Of course, the shape of the battery pack is not limited to a rectangular parallelepiped shape, and can be appropriately designed according to the shape and purpose of use of the electrical equipment to be connected, the required voltage, the number of batteries used, etc., for example, a rectangular parallelepiped shape, a polygonal shape, It can be cylindrical, elliptical, L-shaped or U-shaped.

  The battery pack of the present invention can be suitably applied to battery packs such as bicycles, tools, automobiles, etc., in which a plurality of batteries are connected in parallel and these are connected in series to increase the output.

It is a perspective view which shows the battery block aggregate | assembly built in the battery pack which concerns on one embodiment of this invention. It is the perspective view which looked at the battery block aggregate | assembly of FIG. 1 from the back surface. It is a rear view, a top view, a front view, and a side view of the battery block assembly of FIG. It is sectional drawing which shows the battery block aggregate | assembly which laminated | stacked the battery block using the L-shaped insulating sheet. It is sectional drawing which shows the battery block aggregate | assembly which laminated | stacked the battery block using the U-shaped insulation sheet. It is sectional drawing which shows the battery block aggregate | assembly which laminated | stacked the battery block using the other L-shaped insulation sheet. It is sectional drawing which shows the battery block aggregate | assembly which laminated | stacked the battery block using another L-shaped insulation sheet. It is the perspective view which looked at the battery block aggregate | assembly wired with the lead wire from the board | substrate side. It is the perspective view which looked at the battery block aggregate | assembly of FIG. 8 from the voltage extraction surface side. It is the perspective view which looked at the inner case which accommodated the battery block aggregate | assembly from the board | substrate side. It is the perspective view which looked at the inner case of FIG. 10 from the voltage extraction surface side. It is a perspective view which shows an exterior case. It is the perspective view which looked at the exterior case of FIG. 12 from the reverse.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Outer case 101 ... Upper outer case 102 ... Lower outer case 200, 200A, 200B ... Battery block 201 ... Battery block assembly 210 ... Battery 220 ... Spacer 222 ... Battery holding part 240, 240A, 240B ... Lead plate 240B ... Small Lead plate 242 ... Lead protrusion 246 ... Voltage extraction part 247 ... Equipotential extraction part 248 ... Voltage extraction surface 249, 249B, 249C, 249D ... Insulation sheet 400 ... Inner case 401 ... Upper inner case 402 ... Lower inner case 410 ... Lead Slit 412 ... Sealing rib 414 ... Lead wire holding part 500 ... Lead wire 600 ... Circuit board 610 ... Substrate holder 612 ... Substrate holder rib

Claims (8)

A battery having an end face at a plurality of ends ;
A lead plate for fixing the end faces of the plurality of batteries and holding the batteries in a substantially parallel state;
An insulating spacer that partitions between adjacent batteries;
A plurality of battery blocks comprising:
A circuit board mounted on an edge of a battery block assembly connecting the plurality of battery blocks and mounted with an electronic circuit wired with the battery;
In the battery block assembly , one surface on the end face side of the battery is a voltage extraction surface, and a voltage extraction electrically connected to each lead plate to draw out the potential of the lead plate of each battery block to the voltage extraction surface. And
A storage case for storing the battery block assembly and the circuit board in a state where the voltage extraction unit and the circuit board are electrically connected;
A battery pack having
The battery block facing at least the voltage-extracting surface, the end surface facing the at least one of the voltage extraction surface comprises an insulating sheet that overturn the upper surface of the lead plate,
The insulating sheet in the upper surface to place the voltage extraction portion connected to the other battery blocks, and the voltage taking-out portion, of the at least the voltage extraction surface and facing the battery end faces provided with lead plates of the battery block A battery pack characterized by performing insulation. The battery pack according to claim 1,
Among the plurality of battery blocks constituting the battery block assembly, the lead plate of the battery block located on the voltage extraction surface includes a lead protrusion including a terminal for electrically connecting to the circuit board, An insulating sheet is disposed on the lead projecting portion, and a lead plate of the next battery block adjacent to the battery block is further drawn on the insulating sheet by the voltage extracting portion to the voltage extracting surface. A battery pack in which another insulating sheet is arranged and the same structure is repeated until the lead plates of all the battery blocks are individually pulled out to the voltage extraction surface by the voltage extraction unit. The battery pack according to claim 1,
A battery pack in which the insulating sheet is bent and the battery blocks are insulated by inserting one piece of the insulating sheet bent between adjacent battery blocks. The battery pack according to claim 1,
A battery pack characterized in that the shape of the insulating sheet is U-shaped in cross section, and both end surfaces of the battery block are covered with U-shaped opposing surfaces. The battery pack according to claim 1,
A battery pack, wherein the insulating sheet has an L-shaped cross section and covers one end face of a battery block. The battery pack according to claim 1,
The batteries facing one end face of the battery block assembly are arranged so as to have the same potential for each column of the battery block assembly, and each battery is electrically connected by the same potential extraction portion extended in the column direction. A battery pack characterized by being connected. The battery pack according to claim 1,
The circuit board is arranged on a surface opposite to the lead protruding portion and the voltage extracting portion drawn out to the voltage extracting surface, and the lead protruding portion and the voltage extracting portion and the circuit board are electrically connected by a lead wire. A battery pack characterized by comprising   The battery pack according to claim 1,
  A battery pack, wherein the battery is cylindrical.

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