JP4578147B2 - 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.

The present applicant has previously developed a battery pack having a waterproof property that is reliably protected for the battery contained therein as a battery pack suitable for such applications (Japanese Patent Application No. 2004-4820). On the other hand, when such a battery pack is used with a large current, the amount of heat generated by the battery also increases, and some measures for heat dissipation are required. In particular, with the recent demand for high output, the amount of current in the battery tends to increase. Therefore, improvement of heat dissipation characteristics corresponding to this has been demanded. This is particularly important for battery packs that use an inner case inside the case to protect the battery, because heat tends to be trapped inside. In a structure in which a plurality of batteries are closely arranged inside the case, it is difficult to release heat to the outside. On the other hand, the battery pack also includes a circuit board having a drive circuit such as a charge / discharge circuit for charging / discharging the battery. Such a circuit board also generates a considerable amount of heat because it uses a power element corresponding to a large current. For this reason, it is necessary to consider heat dissipation measures not only for the battery but also for the drive circuit thereof, and a highly reliable heat dissipation structure that can maintain sufficient heat dissipation characteristics even under the use of a large current has been demanded.
JP-A-10-308205

  The present invention has been made to solve such conventional problems. A main object of the present invention is to provide a battery pack that can efficiently dissipate heat generated inside a case to the outside and has improved reliability.

To achieve the above object, the battery pack of the present invention includes a plurality of batteries, a lead plate that secure the end faces of the plurality of batteries to retain the battery to each other in a flat line state between the battery adjacent to A battery block including an insulating spacer for partitioning, a substrate mounted on one surface of the battery block and mounted with an electronic circuit wired with the battery, and a storage case for storing the battery block and the substrate. This battery pack is configured such that a lead plate forms a lead protruding portion with a portion protruding, and heat is radiated by the lead protruding portion. As a result, the lead protrusion for radiating the heat generated by the battery can also be used as a terminal for detecting the intermediate potential of the battery group built in the battery pack.

Another battery pack of the present invention, the lead plate is provided with a plurality of leads bent portions which are vertically into bent in the plane of fixing the end face of the battery. Accordingly, there can be obtained an advantage that a plurality of lead bent portions are provided, the lead plate is three-dimensionally configured to increase the surface area, and the heat dissipation of the lead plate can be improved.

  Furthermore, in another battery pack of the present invention, the lead protrusion includes a pair of lead bent portions. Thereby, the heat transferred from the battery to the lead plate is efficiently radiated from the lead protrusion.

Furthermore, other battery pack of the present invention, the lead bending portions are bent such that the spacer and the same plane, and the spacer is protruded to face the lead bent part, the spacer and the lead bending The part is in contact. As a result, the lead bent parts of adjacent lead plates are insulatively insulated by the spacer so that they do not short-circuit, and the lead bent part is in contact with the spacer to conduct heat and efficiently dissipate the heat generated by the battery. it can.

  Furthermore, in another battery pack of the present invention, the substrate is disposed on one surface of the battery block and in the direction opposite to the protruding direction of the lead protruding portion protruding from the lead plate. Thereby, the heat dissipation path of the heat generated by the substrate and the heat generated by the battery can be separated in different directions, and heat can be easily diffused to improve heat dissipation.

  Furthermore, in another battery pack of the present invention, the lead wire is fixed to the lead protruding portion of the lead plate, and the substrate and the lead plate are electrically connected via the lead wire. As a result, the lead protrusions arranged on the opposing surfaces and the substrate can be electrically connected via the lead wires, and a heat radiation effect from the lead wires fixed to the lead protrusions can also be obtained.

Furthermore, in another battery pack of the present invention, a lead slit is formed in a part of the storage case so that the lead protrusion protrudes from the storage case with the battery block inserted in the storage case, and the lead battery so as to surround the slit, it forms a sealing rib upstanding protruding direction flat line direction of the lead protrusion further the height of the sealing rib has inserted the lead protrusion in the lead slit In this state, the lead rib is configured to be higher than the upper end of the lead protrusion, and the lead rib is connected to the lead protrusion and the sealing rib is filled with silicon-based resin as a sealing material and fixed. As a result, the lead plate and the lead wire are securely fixed by being filled with the silicon resin, and the heat dissipation is enhanced by the silicon resin having excellent thermal conductivity.

  Furthermore, in another battery pack of the present invention, the sealing silicon-based resin contains alumina. Thereby, since the silicon resin containing alumina is excellent in heat conduction, the heat dissipation by the silicon resin can be improved.

  Furthermore, in another battery pack of the present invention, the spacer protrudes from at least one end face of the battery block, and insulates adjacent lead plates. Thus, the spacers that insulate the batteries can also be used to insulate the lead plates.

  The battery pack of the present invention has an excellent advantage that the heat generated by the built-in battery is conducted to the lead plate and can be reliably radiated. Particularly in the present invention, by projecting the lead protrusion from the lead plate, heat can be effectively radiated by the lead protrusion, and the lead protrusion can also be used as a terminal for detecting the intermediate potential of the battery group. Thus, the structure can be simplified and the cost can be kept low. Moreover, the heat dissipation can be further enhanced by filling with a silicon resin having excellent thermal conductivity.

  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'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.
[Exterior case 100]

  FIG. 1 shows an outer shape of a battery pack according to an embodiment of the present invention, and FIG. The battery pack shown in these figures has a plurality of batteries built in, and the exterior is covered with an outer case 100. 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. An exterior case 100 shown in FIG. 1 is divided into an upper exterior case 101 and a lower exterior case 102. In addition, a handle 103 is integrally formed on the upper portion to facilitate carrying. Further, the lower exterior case 102 shown in FIG. 1 is provided with connection ribs 104 along the outer peripheral surface in order to connect the upper exterior case 101. Similarly, connecting ribs 104 are also provided on the outer periphery of the upper outer case 101, and the upper outer case 101 and the lower outer case 102 are connected by connecting the connecting ribs to each other. Further, the outer case is fixed by screwing in this state.

A plurality of batteries are accommodated in the exterior case 100. The battery fixing method is shown in FIGS. As shown in these drawings, each battery 210 has a cylindrical shape, and constitutes a battery block 200 in which a plurality of batteries are arranged in the same direction and stacked in an offset shape. By arranging the batteries 210 in an offset shape, a large number of cylindrical batteries 210 can be arranged side by side efficiently. In the example of FIG. 3, seven batteries 210 are stacked in two stages, and the seven batteries 210 are connected in series, and these are further connected in parallel. However, the number, arrangement, and connection form of the batteries are not limited to this example. For example, the batteries may be arranged in a grid pattern instead of the offset arrangement.
[Battery 210]

  The battery 210 of the battery block 200 is a rechargeable secondary battery. In the battery pack of FIG. 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 is not limited to a lithium ion battery, and a secondary battery such as a nickel-hydrogen battery or a nickel-cadmium battery can also be used.

[Spacer 220]
As shown in FIG. 3, a spacer 220 is disposed between the batteries. As shown in FIG. 4, the spacer 220 has a structure in which the cross section has a honeycomb shape, and forms a battery holding portion 222 that is open to hold the side surface of the cylindrical battery 210. The battery holding part 222 is formed in a honeycomb type or circular shape having a substantially hexagonal cross section so that the curved surface of the cylindrical battery 210 can be reliably held. Further, if a member that elastically deforms is used for the spacer 220, the curved surface of the battery 210 can be clamped and securely held. Or the spacer surface does not necessarily need to be planar, and the surface may be uneven. The spacer 220 of FIG. 4 is formed in two stages by offsetting the seven battery holding portions 222, and the battery block 200 as shown in FIG. The spacer 220 is made of an insulating member, and is formed by integrally molding a hard or soft plastic, for example. The spacer 220 divides the battery holding part 222 so that a plurality of batteries 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 of FIG. In addition, when a member having a good thermal conductivity such as a metal is used for a part or all of the spacer 220, it is possible to promote heat dissipation of the battery that has generated heat and prevent a decrease in battery life. However, the spacer is not limited to the honeycomb shape, and may be a flat plate shape, and a plurality of flat spacers may be inserted between the batteries.

[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 of FIG. 3, a lead plate 240 that connects the terminals of the four batteries 210 on the upper, lower, left, and right sides and a lead plate 240 that connects the terminals of the upper and lower two batteries 210 are used. These lead plates 240 form horseshoe-shaped or U-shaped slits 241 to ensure electrical connection with the terminals of the battery 210. The inside of the horseshoe-shaped slit 241 is welded to the electrode of the battery 210, and the electrode is spot welded by resistance welding. In the lead plate 240 having this structure, since the welded portion separated by the slit 241 can be deformed with respect to the lead plate 240, the battery 210 is detached from the lead plate 240 by absorbing the dimensional error of the battery 210 and vibration due to impact. Can be effectively prevented. However, the welded portion does not necessarily need to be inside the horseshoe-shaped slit 241, and a V-shaped or U-shaped slit can be provided and the inside can be used as the welded portion. Furthermore, the lead plate 240 has a plurality of positions so that the non-opening portion of the slit 241 provided with the welded portion on the inside faces the direction of the battery 210 connected in series, that is, in a posture facing each other in the vertical direction. The slit 241 is opened. The lead plate 240 having this structure has a feature that a battery array connected in series can be connected with a low resistance without being divided by a slit in the shortest distance.
[Lead protrusion 242]

The lead plate 240 has a lead protrusion 242 protruding at one end. The lead protrusion 242 protrudes below the lead plate 240 in the examples of FIGS. 2 and 3. The lead protrusion 242 also serves as a terminal for measuring the intermediate potential of the battery group, and forms a hole for wiring the lead wire. Thus, by forming the intermediate potential detection terminal larger, the function of the heat sink can be shared, and the number of parts can be reduced and the configuration can be simplified.
[Lead bent part 244]

  Furthermore, in order to improve the heat dissipation of the lead protrusion 242, lead bent portions 244 are provided at both ends thereof. The lead bent portion 244 is formed by forming the tip of the lead protruding portion 242 in a T shape and bending it substantially vertically. Thus, by the lead bent part 244 bent perpendicularly from the plane of the lead plate 240, the surface area can be widened and three-dimensionally configured to improve heat dissipation. In addition, the lead protruding portion 242 and the lead bent portion 244 are integrally formed with the lead plate 240.

  The lead protrusion 242 is inserted into a lead slit 410 formed in the lower outer case 102 when the battery block 200 is inserted into the lower inner case 402 as shown in FIG. 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. Further, when the lead protrusion 242 is inserted into the lead slit 410, the lead bent portion 244 is not bent, and the lead bent portion 244 is bent after insertion. Thus, by inserting the lead protrusion 242 into the lead slit 410, the battery block 200 is positioned in the lower inner case 402, and the lead bent portion 244 is bent and held so as not to come off.

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 a circuit board 600 described later. Thus, wiring is performed on each lead plate 240 in order to measure the terminal voltage of the battery 210. In particular, when the lithium ion battery 210 is used, it is necessary to detect the battery voltage in order to protect the battery 210 and monitor the voltage across the battery block as an intermediate potential of the battery group. For this reason, the voltage of each lead plate 240 can be detected and the terminal voltage of a predetermined battery block can be monitored.
[Sealing rib 412]

Further, a sealing rib 412 is provided around the lead slit 410 as shown in FIG. FIG. 6 is a perspective view showing the bottom surface of the inner case 400. 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.
[Encapsulant 300]

  Sealing is performed by injecting a sealing material 300 such as a silicon-based resin into a region surrounded by the sealing rib 412. As a result, the lead plate 240 and the lead wire 500 are fixed in a state where they are reliably electrically connected, and are provided with heat dissipation and waterproofing. When a silicon-based resin is used as the filler, the heat conductivity is excellent, and the region surrounded by the sealing rib 412 can have heat dissipation. In particular, when alumina is contained in the sealing silicon-based resin, the thermal conductivity of the silicon-based resin is further improved, so that it can be suitably used.

The sealing rib 412 is provided on the surface of the lower exterior case 102 by integral molding. As shown in FIG. 6, 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 exterior case 102, 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.
[Thermal element]

Further, the thermal element is also fixed in the same manner as the lead protrusion 242 described above. The thermal element is used 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. In the example of FIG. 3, a thermistor is used as the thermal element. As shown in FIG. 3, the thermosensitive element which is a thermistor is located in the valley of the battery 210, so that the temperature of two batteries can be measured with one thermosensitive element, and the heat sensitive element is utilized using the space between the valleys. It is possible to earn an element arrangement space. The thermal element is fixed to the thermal element holder 250, and the thermal element holder notch 224 is formed in the spacer 220 so that the thermal element holder 250 can be fixed in the valley of the battery 210. In a state where the thermal element is fixed to the battery block 200 with the thermal element holder 250, the battery block 200 is fixed by winding the periphery of the battery block 200 with a fixing tape 260 such as a double-sided tape so as to attach the side surface portion of the battery 210. To do. Thereby, the battery 210 is securely fixed so as not to be detached from the spacer 220.
[Lead plate 251 for thermal element]

Further, a heat sensitive element lead plate 251 is fixed to the heat sensitive element holder 250 so that a part of the heat sensitive element is connected for terminal connection of the heat sensitive element. The thermal element lead plate 251 protrudes in the same direction as the lead protruding portion 242 and is inserted into the thermal element lead slit 420 opened in the inner case 400 in the same manner as the lead slit 410. Similarly, a thermal element lead sealing rib 422 is formed around the thermal element lead slit 420. With the thermal element lead plate 251 inserted into the thermal element lead slit 420, one end of the lead wire 500 is wired in the hole formed in the thermal element lead plate 251, and the other end is used for the thermal element of the circuit board 600. Wired with the circuit. Further, in the state where the lead plate 251 for the thermal element is wired, the same sealing as described above is performed to protect it from waterproofing and short circuit. Further, the height of the side surface constituting the thermal element lead sealing rib 422 is higher than the upper end of the thermal element lead protrusion 252 in a state where the thermal element lead protrusion 252 is inserted into the thermal element lead slit 420. Designed to be high. This prevents a part of the thermal element lead protrusion 252 from being exposed after sealing, thereby preventing a short circuit of the thermal element.
[Inner case 400]

  The battery block 200 configured as described above is inserted into the inner case 400 and fixed. The inner case 400 is divided into upper and lower parts, and is composed of a box-shaped lower inner case 402 having an opening and a lid-shaped upper inner case 401 as shown in FIG. As shown in FIG. 5, after the assembled battery block 200 is inserted into the lower inner case 402 with the upper opening, the opening is closed with the upper inner case 401, and this is performed by thermal welding or bonding such as ultrasonic welding. It is fixed airtight at the part. 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 stores a battery block directly in an exterior case, without using an inner case. The storage case in the claims corresponds to an inner case or an outer case. Moreover, although the case where a battery is arrange | positioned in offset shape was demonstrated in said example, this invention is not restricted to this arrangement | positioning, You may arrange | position a battery in a grid pattern. FIG. 7 shows a perspective view of a lead plate 240B of a battery pack according to another embodiment of the present invention. This arrangement example can be suitably used in the case of a square battery or the like in addition to a cylindrical battery. In addition, the lead plate 240B disposed on the back side in FIG. 7 is arranged in an offset manner with respect to the lead plate 240B on the front side, thereby connecting two vertically adjacent batteries in parallel, and adjacent to the left and right batteries. Are connected in series. In the example of FIG. 7, for explaining the lead protrusion 242B, a perspective view of the lead plate 240B in a posture in which the lead protrusion 242B protrudes upward is shown. In the lead plate 240B shown in this figure, a lead protrusion 242B is integrally formed upward from a substantially center of a lead plate main body 243 formed in a substantially square flat plate shape, and is further formed on both side surfaces of the lead protrusion 242B. The lead bent portion 244B is formed by integral molding, is bent substantially vertically, and protrudes outward. Further, holes are formed in the lead plate main body 243 for spot welding at positions where the lead plate main body 243 is fixed to the end face of the battery, and holes are formed in the lead protruding portion 242B for wiring with the lead wires. As described above, the large lead protrusion 242B is formed, and the lead bent portion 244B is formed to increase the surface area, thereby improving the heat dissipation characteristics.

  Further, another lead bent portion 244C is formed on the side surface of the lead plate main body 243. The lead bent portion 244C has the same effect as the lead bent portion 244B of the lead protruding portion 242B to increase the surface area and improve the heat dissipation characteristics, and also to effect heat conduction with the spacer 220B by contacting with the spacer 220B. Can also be obtained. The spacer 220B shown in FIG. 7 is formed in a flat plate shape, and is inserted between the batteries to insulate the batteries. Furthermore, the spacer 220B protrudes from one end face of the battery block and is inserted between the adjacent lead plates 240B. As a result, the adjacent lead plates 240B are reliably insulated by the spacer 220B, thereby preventing conduction and improving safety. Thus, the advantage that the spacer 220B that insulates the batteries can be used also for the insulation between the lead plates 240B is obtained. The spacer 220 </ b> B protruding from between the battery blocks is in contact with the lead bent portion 244 </ b> C on the side surface of the lead plate main body 243 so as to be able to conduct heat.

  The spacer 220B is inserted between the batteries and brought into contact with the sides of the battery so that the heat generated by the battery is thermally conducted to the spacer 220B. The heat conducted to the spacer 220B is conducted to the lead bent part 244C on the side surface of the lead plate main body 243, so that the heat generated in the battery can be effectively dissipated from the lead plate 240B. In particular, since a plurality of batteries built in the battery pack are arranged adjacent to each other, heat is easily trapped in the structure. On the other hand, heat is conducted to the end face side of the battery by the spacer 220B inserted between the batteries, and is dissipated by the spacer 220B arranged on the end face, so that only the surface in contact with the spacer 220B on the end face of the battery. In addition, since a heat conduction path is formed also from the battery side surface, an advantage that heat can be efficiently radiated can be obtained. Needless to say, if necessary, a heat radiating member such as a heat sink can be connected to the lead plate in a heat conducting state to further improve heat dissipation.

Furthermore, in addition to the structure in which the heat generated by the battery is radiated by the lead plate, the heat radiation characteristics can be further improved by arranging the heat generated in the circuit board and the heat radiation path to be separated. A structure for realizing this will be described with reference to FIG. Since the circuit board 600B on which the driving circuit of the battery 210 is mounted includes a power semiconductor element or the like, the circuit board 600B itself also generates heat. For this reason, a structure for efficiently releasing both the heat generated in the battery 210 and the heat generated in the circuit board 600B to the outside of the battery pack is required. Therefore, in the present embodiment, the circuit board 600B is arranged on one surface of the battery block, in the example of FIG. 8, on the upper surface, while the lead protrusion 242B of the lead plate 240B fixed to the end surface of the battery block is replaced with the circuit board 600B. By projecting downward on the opposite side of the arrangement surface, the heat dissipation path of the circuit board 600B and the heat dissipation path of the battery 210 are separated vertically. That is, as indicated by the arrows in FIG. 8, the circuit board 600 </ b> B arranged at the upper side dissipates heat substantially above the battery pack, while the lead plate 240 </ b> B with the lead protrusion 242 </ b> B protruding downwardly generates heat from the battery 210. Is generally dissipated toward the bottom of the battery pack. In this way, by disposing the heat dissipation paths separately for the two heat sources of the circuit board 600B and the battery 210, it is possible to avoid a situation in which these heats interact and adversely affect the heat dissipation. Realized.
[Vent 430]

Returning to FIG. 6, a ventilation hole 430 is opened in the inner case 400. The vent 430 is opened in an inclined surface 440 formed on the end surface of the lower inner case 402. By forming the vent 430 in the inclined surface 440, the distance from the outer case 100 covering the inner case 400 is maintained, and the amount of ventilation is secured. The vent hole 430 is closed by attaching a breathable and waterproof sheet 450 from the inside. Thereby, adjustment of internal pressure and waterproofness are maintained. When the inner case 400 is sealed, the inside of the inner case may become a high pressure due to the gas discharged from the battery 210 inside. On the other hand, it is necessary to waterproof to protect the battery inside the inner case. Therefore, by passing through a filter that allows air to pass through but does not allow moisture to pass therethrough, it is possible to achieve both waterproofness and air permeability, prevent the inner case 400 from being deformed due to expansion and contraction due to internal pressure, and at the same time, keep the internal battery 210 from moisture. Protect from. For such a breathable and waterproof sheet 450, Gore-Tex (registered trademark) or the like can be used.
[Lead wire 500]

As shown in FIGS. 6 and 9, the circuit board 600 is fixed to the opposite surface of the inner case 400 that faces the surface where the lead slits 410 and the like are opened. The circuit board 600 is wired with the lead plate 240 on the opposite surface via the lead wire 500. At this time, the lead plate 240 and the circuit board 600 are wired in a straight line so that the lead wires 500 are not orthogonal to each other. Since the battery voltage is applied to the lead wire 500, consideration is required so that a short circuit is unlikely to occur. When many lithium ion batteries are connected in series as described above, it is necessary to connect a plurality of lead wires to the circuit board 600 in order to monitor the battery voltage. Since a battery voltage is applied to each lead wire, there is a risk of short circuit if the lead wire is routed in a situation where it is wired with a plurality of lead wires. Therefore, in the present embodiment, the lead wires 500 are arranged so as to extend in a centipede foot shape, that is, in substantially the same direction and in a direction close to parallel so that the lead wires are not orthogonal to each other. In order to maintain the lead wire 500 in this state, in addition to the lead wire holding portion 414 formed on the side sealing rib 412 described above, the lead rib 460 is also provided on the side surface of the inner case 400 as shown in FIG. Is forming. Further, the circuit is designed so that the terminals on the circuit board are also arranged at the end portions of the circuit board 600 in the vicinity of the positions corresponding to the respective lead boards 240 so that wiring with the corresponding lead boards 240 is easy. Such wiring by the lead wire 500 reduces the possibility of a short circuit. In the case of connection by a connector, since the terminals to which the battery voltage is applied are arranged close to each other, it is conceivable that the metal piece is short-circuited for some reason such as being inserted into the connector. Therefore, the terminals and paths to which the battery voltage is applied can be separated, and contact between leads that causes a short circuit is also eliminated, so that high safety is ensured.
[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. 9 shows a perspective view of a state in which 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 intermediate potential of the battery block 200 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.
[Fixing the substrate holder 610]

The substrate holder 610 including the circuit substrate 600 is fixed on the inner case 400 as shown in FIG. Although it is fixed by screwing here, it goes without saying that a method such as locking by hook or adhesion can also be used. With the substrate holder 610 fixed on the inner case 400 and the display substrate 700 temporarily fixed, the inner case 400 is inserted into the outer case 100 as shown in FIG. The outer case 100 has a structure divided into upper and lower parts, and is designed to have a size and shape that can accommodate the inner case 400 therein. As shown in FIG. 10, an inner case holding rib 106 is projected inside the outer case 100. The inner case holding rib 106 is integrally formed so as to protrude vertically from the inner surface of the upper outer case 101. By bringing the tip of the inner case holding rib 106 into contact with the inner case 400, the inner case 400 is securely held so as not to move inside the outer case 100.
[Buffer material 800]

Furthermore, a cushioning material 800 is disposed between the inner case 400 and the outer case 100 as shown in FIG. The buffer material 800 is fixed to the side surface of the inner case 400 and the bottom surface where the substrate holder 610 is not provided in a state where the lead wire 500 is wired and fixed. Accordingly, the cushioning material 800 can be interposed between the inner case 400 and the outer case 100, and the inner case 400 is protected from an external impact. The inner case holding rib 106 holds the inner case 400 so that the inner case 400 is sandwiched inside the outer case 100 by abutting the tip of the inner case 400 on the cushioning material 800 covering the outer periphery of the inner case 400. As a result, the inner case 400 is securely held in the outer case 100 without rattling, and is protected from shock and vibration by the cushioning material 800. The cushioning material 800 can be an elastic body with good cushioning properties, and silicon rubber, foam, or the like can be used. The cushioning material 800 is attached to the surface of the inner case 400 with an adhesive tape or the like. Further, the area of the substrate holder 610 that accommodates the circuit board 600 is designed to be smaller than the upper surface of the inner case 400. Further, the substrate holder 610 is positioned and fixed so as to be included in the inner case 400 so as not to protrude from the upper surface of the inner case 400. Accordingly, only the inner case 400 is fixed in contact with the outer case 100. In other words, the substrate holder 610 is not in direct contact with the inner surface of the outer case 100 and is placed on the inner case 400. As a result, even if a strong impact such as dropping the exterior case 100 is applied, the impact is not transmitted directly to the circuit board 600 but is propagated through the buffer material 800 and the inner case 400, so that it is mounted on the circuit board 600. Electrical connection parts such as soldered electronic parts and soldered parts are protected. As described above, the structure in which the inner case 400 is held by the inner case holding rib 106 and the cushioning material 800 protects the circuit board 600 from impacts and vibrations, and the reliability at this portion is improved.
[Display substrate 700]

  The display substrate 700 includes a display unit 701 that displays the remaining amount of the battery. For example, a 7-segment display such as a liquid crystal display or an LED display is used. The display substrate 700 exposes the display unit 701 to the outside through the opening window 108 opened in the outer case 100. For this reason, the display unit 701 needs to be fixed to the outer case 100. On the other hand, the display substrate 700 needs to be wired with the circuit substrate 600 in order to drive the display portion 701. For this reason, in the conventional assembly process, a long lead wire is wired from the display board to the circuit board, and after fixing the display board to the outer case first, the inner case including the board holder is accommodated in the outer case. . In this method, it is necessary to fix the circuit board to the outer case in a state where the circuit board fixed to the inner case and the display board are wired, and there is a problem that it is difficult to work because the lead wire gets in the way. . Further, if the lead wire is lengthened to facilitate the work, the long lead wire is likely to be sandwiched between the upper exterior case and the lower exterior case when the exterior case is assembled. Furthermore, the space for storing the long lead wires inside the outer case is also a problem.

  Therefore, in the battery assembly method, first, the display substrate 700 is temporarily fixed on the inner case 400, the inner case 400 is inserted into the outer case 100, the outer case 100 is closed, and then screwed from the outside of the outer case 100. Thus, the display substrate 700 is fixed. As a result, positioning for fixing the display substrate 700 to the outer case 100 can be easily performed, and there is no need to lengthen the lead wires, so that the efficiency of the assembly work is greatly improved.

  Specifically, a boss 470 is provided on the inner case 400 as a temporary fixing mechanism for temporarily fixing the display substrate 700. As shown in FIG. 11, the boss 470 is formed so as to protrude in a cylindrical shape at two positions so that the display substrate 700 is disposed at a position adjacent to the substrate holder 610. By causing the display substrate 700 to be adjacent to the circuit substrate 600, the lead portion for wiring between them can be made the shortest. Further, the display substrate 700 is provided with a boss hole 710 into which the boss 470 can be inserted on the bottom surface, and a display substrate screw hole 720 for screwing on the inner surface of the upper exterior case 101. Preferably, the boss hole 710 and the display substrate screw hole 720 are arranged in a straight line. Thus, holes can be formed in the display substrate 700 at the same time. The boss hole 710 and the boss 470 are not provided with a structure such as a screw groove for fastening a screw. These are temporary fixing mechanisms that are actually fixed between the display substrate 700 and the outer case 100, and fixing mechanisms such as screw grooves are provided in the display substrate screw holes 720. Further, as shown in FIG. 12, a screw hole 109 for screwing the display substrate 700 located on the back side of the upper exterior case 101 is opened in the upper exterior case 101. The boss 470 formed on the inner case 400 is designed so that the display substrate 700 is determined at a position where the screw hole 109 of the outer case 100 and the display substrate screw hole 720 coincide after the inner case 400 is inserted into the outer case 100. Is done. By positioning the display substrate 700 using the bosses 470, the inner case 400 is inserted into the outer case 100 and then screwed through the screw holes 109 to fix the display substrate 700 to the outer case 100. As a result, the display substrate 700 is securely fixed to the outer case 100 from a state in which the display substrate 700 is temporarily fixed on the inner case 400. Thereafter, the display label 110 is affixed to the inner case 400 so as to hide the screw hole 109. Accordingly, the screw hole 109 can be waterproofed, and inadvertent disassembly can be prevented by preventing the screw from being exposed to the outside. As shown in FIG. 12, the display label 110 may be a single seal with the opening window 108 opened, or a plurality of seals that respectively close screw holes.

The process of assembling the above battery pack will be described below.
(1) First, the battery block shown in FIG. 3 is configured. The batteries 210 are inserted into the battery holding portions 222 of the spacers 220, and the lead plate 240 is fixed to the end surface of the battery 210. The lead plates 240 are respectively arranged on the left and right sides of the battery 210 so that the lead protrusions 242 are in the same direction. In the example of FIG. 3, three lead plates 240 for fixing four electrode terminals, one for each of the upper and lower left and right sides, and one lead plate 240 for fixing two upper and lower electrode terminals are used at both ends of the battery 210. Thus, a total of 14 batteries 210 are connected in series, and the two are connected in parallel. In addition, a thermal element holder 250 that holds the thermal element in the valley of the battery 210 is fixed. The thermal elements are preferably provided at a plurality of locations, for example, between the second and third from the upper right side of the battery 210 and between the second and third from the lower left side. Further, the lead protrusion 252 for the thermal element is protruded in the same direction as the lead protrusion 242. Thereafter, the periphery of the battery block 200 is wound with a fixing tape 260 such as a double-sided tape, and the cylindrical side surface of the exposed battery 210 is bonded with the tape to fix the battery 210.

  (2) The battery block 200 is inserted into the lower inner case 402 as shown in FIG. As shown in FIG. 6, a sheet 450 is fixed to the lower inner case 402 so as to cover the vent hole 430 from the inside in advance. The lead protrusion 242 and the thermal element lead protrusion 252 are inserted into the lead slit 410 and the thermal element lead slit 420 opened in the lower inner case 402, respectively. On the other hand, after the battery block 200 is inserted into the opening of the lower inner case 402, the opening is closed with the upper inner case 401, the upper and lower inner cases 402 are welded by ultrasonic welding, and the portion is airtightly fixed. A substrate holder 610 is placed on the upper surface of the upper inner case 401 and fixed by screws. As shown in FIG. 9, the substrate holder 610 is in a state of being waterproofed by inserting a substrate on which electronic components or the like are mounted in advance and wired with lead wires 500 and potting with urethane resin. After fixing the substrate holder 610 to the upper inner case 401, the lead wire 500 is folded back to the lead plate 240 side on the opposite surface. At this time, the plurality of lead wires 500 are folded downward so as not to cross each other and are held by the lead ribs 460. Then, lead wires 500 are wired on each lead plate 240 and sealed so that the protruding portions are embedded with silicon as shown in FIG.

  (3) Also, as shown in FIG. 11, the display substrate 700 is temporarily fixed to the upper surface of the inner case 400. The boss hole 710 of the display substrate 700 is inserted into the boss 470 of the inner case 400, and the display substrate 700 is positioned and held on the inner case 400. In this state, the inner case 400 is inserted into the outer case 100, the upper outer case 101 and the lower outer case 102 are locked by the left and right locking portions shown in FIG. 10, and then fixed by screws. Finally, as shown in FIG. 12, screws are inserted from the screw holes 109 of the upper outer case 101 to fix the display substrate 700 to the upper outer case 101, and then the display label 110 is pasted so as to cover the screw holes 109. . Thereby, the battery pack is assembled.

  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 external shape of the battery pack which concerns on one embodiment of this invention. It is sectional drawing which shows the battery pack of FIG. It is a perspective view which shows the battery block incorporated in the battery pack of FIG. It is a perspective view which shows the spacer used for a battery block. It is a perspective view which shows the state which inserts a battery block in an exterior case. It is the perspective view which looked at the inner case from the bottom. It is a perspective view which shows the lead plate used for the battery pack which concerns on other embodiment of this invention. It is an image figure which shows the thermal radiation path | route in the battery pack which concerns on embodiment of this invention. It is a perspective view which shows the state which fixed the circuit board on the inner case. It is a perspective view which shows the state which inserts an inner case in an exterior case. It is a perspective view which shows the state which temporarily fixes a display board to the upper surface of an inner case. It is a perspective view which shows the state which fixes a display board from the outer side of an exterior case.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Outer case 101 ... Upper outer case 102 ... Lower outer case 103 ... Handle 104 ... Connecting rib 106 ... Inner case holding rib 108 ... Opening window 109 ... Screw hole 110 ... Display label 200 ... Battery block 210 ... Battery 220, 220B ... spacer 222 ... battery holding part 224 ... notch 240, 240B for heat sensitive element holder ... lead plate 241 ... slit 242,242B ... lead protruding part 243 ... lead plate main body 244,244B, 244C ... lead bent part 250 ... heat sensitive element Holder 251 ... Thermal element lead plate 252 ... Thermal element lead protrusion 260 ... Fixing tape 300 ... Sealing material 400 ... Inner case 401 ... Upper inner case 402 ... Lower inner case 410 ... Lead slit 412 ... Sealing rib 414 ... Lead wire holding part 420 ... Thermal element element Slit 422 ... Rib for heat-sensitive element lead sealing 430 ... Vent hole 440 ... Inclined surface 450 ... Sheet 460 ... Lead rib 470 ... Boss 500 ... Lead wire 600, 600B ... Circuit board 610 ... Substrate holder 612 ... For substrate holder Ribs 620 ... Resin 700 ... Display substrate 701 ... Display portion 710 ... Boss hole 720 ... Display substrate screw hole 800 ... Buffer material

Claims (6)

Multiple batteries,
A lead plate for holding the cell together into the flat line state by fixing the end faces of the plurality of batteries,
An insulating spacer that partitions between adjacent batteries;
A battery block comprising:
A board on which an electronic circuit arranged on one surface of the battery block and wired with the battery is mounted;
A storage case for storing the battery block and the substrate;
A battery pack having
The lead plate forms a lead protrusion partly protruding, and is configured to radiate heat with the lead protrusion part,
The lead plate is provided with a plurality of leads bent portions which are vertically into bent in the plane of fixing the end face of the battery,
The lead bending portions are bent such that the spacer and the same plane, and wherein the spacer is protruded to face the lead bent portion, comprising contacting the said spacer and the lead bending portion A battery pack characterized by that. Multiple batteries,
A lead plate for holding the cell together into the flat line state by fixing the end faces of the plurality of batteries,
An insulating spacer that partitions between adjacent batteries;
A battery block comprising:
A board on which an electronic circuit arranged on one surface of the battery block and wired with the battery is mounted;
A storage case for storing the battery block and the substrate;
A battery pack having
The lead plate forms a lead protrusion partly protruding, and is configured to radiate heat with the lead protrusion part,
The battery pack is characterized in that the substrate is disposed on one surface of the battery block and in a direction opposite to a protruding direction of a lead protruding portion protruding from the lead plate. 3. The battery pack according to claim 2 , wherein a lead wire is fixed to a lead protruding portion of the lead plate, and the substrate and the lead plate are electrically connected via the lead wire. Pack battery. Multiple batteries,
A lead plate for holding the cell together into the flat line state by fixing the end faces of the plurality of batteries,
An insulating spacer that partitions between adjacent batteries;
A battery block comprising:
A board on which an electronic circuit arranged on one surface of the battery block and wired with the battery is mounted;
A storage case for storing the battery block and the substrate;
A battery pack having
The lead plate forms a lead protrusion partly protruding, and is configured to radiate heat with the lead protrusion part,
In a state where the battery block is inserted into the storage case, a lead slit is formed in a part of the storage case so that the lead protrusion protrudes from the storage case, and surrounds the lead slit , in a state in which forming the ribs for sealing the upstanding protruding direction flat line direction of the lead protrusion further the height of the sealing rib has inserted the lead projecting portion to the lead slit, the lead projecting A battery pack characterized in that it is configured to be higher than the upper end of the portion, and in which the lead wire is connected to the lead protruding portion, the sealing rib is filled with a silicon-based resin as a sealing material and fixed. 5. The battery pack according to claim 4 , wherein the silicon tree for sealing contains alumina. Multiple batteries,
A lead plate for holding the cell together into the flat line state by fixing the end faces of the plurality of batteries,
An insulating spacer that partitions between adjacent batteries;
A battery block comprising:
Arranged on one side of the battery block;
A substrate on which an electronic circuit wired with the battery is mounted;
A storage case for storing the battery block and the substrate;
A battery pack having
The lead plate forms a lead protrusion partly protruding, and is configured to radiate heat with the lead protrusion part,
A battery pack, wherein the spacer protrudes from at least one end face of the battery block and insulates adjacent lead plates.

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