JP2005100696A - Cell battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently, simply, and inexpensively mass-produce a battery pack while a substrate is arranged in the accurate position of an outer case. <P>SOLUTION: The battery pack is formed by fitting a thin battery 2 to the plastic outer case 1. The outer case 1 has a first case 1A and a second case 1B divided on the front and back sides of the thin battery 2. The first case 1A and the second case 1B are formed in a square framework along the outside of the side surface and the end surface of the thin battery 2. The first case 1A uses one side as a substrate housing part 25 housing a substrate 5 on the inside. The substrate housing part 25 houses the substrate 5 between both side walls 25B by integrally forming the side wall 25B projecting inward along the both side edges of a body plate part 25A. The substrate 5 has a fitting projection part 26 projecting from the side edge, and has a through hole 27 housing the fitting projection part 26 installed in the side wall 25B of the substrate housing part 25. The fitting projection part 26 is housed in the through hole 27, and the substrate 5 is arranged in the specified position on the inside of the substrate housing part 25. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a battery pack in which a thin battery is fixed to an exterior case.

A battery pack for storing a thin battery in an outer case has been developed (see Patent Document 1).
JP 2001-307694 A

  In the battery pack described in this publication, as shown in FIG. 1, a thin battery 42 is accommodated in an outer case 41, and a substrate 43 is disposed between the thin battery 42 and the outer case 41. The substrate 43 fixes the output terminal 47. The substrate 43 is connected to the holder 44 and disposed between the thin battery 42 and the outer case 41. In order to place the substrate 43 at a fixed position, the holder 44 is provided with four fitting protrusions 45 as shown in FIG. In order to fit the fitting convex portion 45, the substrate 43 is provided with fitting concave portions 46 on both sides. The substrate 43 is placed at a fixed position by inserting the fitting convex portion 45 of the holder 44 into the fitting concave portion 46. In this battery pack, a holder 44 is disposed between the substrate 43 and the thin battery 42, and the substrate 43 is disposed at a fixed position.

  In the battery pack having this structure, it is difficult to place the substrate at an accurate position. This is because the substrate is connected to a thin battery through a holder to form a battery core pack, the battery core pack is disposed at a fixed position of the outer case, and the substrate is disposed at a fixed position of the outer case. The present inventor has developed a battery pack having a structure in which a substrate is placed at an accurate position of the exterior case, with the exterior case and the substrate being a fitting structure. This battery pack has a structure in which a fitting concave portion is provided on a substrate and a fitting convex portion to be inserted into the fitting concave portion protrudes from the inner surface of the outer case. In the battery pack having this structure, the substrate and the outer case can be connected so that the relative position does not shift. This is because the substrate is directly fitted and connected to the outer case. However, the battery pack having this structure has a drawback that it is necessary to use an extremely complicated and precise mold for molding the outer case, and the manufacturing cost becomes extremely high, and the mass production cannot be efficiently performed. In particular, the thinner the thin battery, the more difficult it is to mold the outer case.

  Further, as shown in FIG. 1, in the battery pack in which the outer case 41 is divided into the first case 41 </ b> A and the second case 41 </ b> B and the thin battery 42 is accommodated, the substrate 43 is disposed at an accurate position of the outer case 41. Difficult to do. In particular, in a battery pack having a structure in which the entire battery pack is compact and the first case and the second case are ultrasonically welded and firmly connected, it is difficult to place the substrate at an accurate position. In order to make the entire battery pack compact, it is necessary to thin the substrate storage portion of the outer case that stores the substrate inside. Thin substrate storage is difficult to ultrasonically weld and securely connect to its side edges. For this reason, it is necessary to provide a side wall along the side edge of the substrate storage portion to make the side edge substantially thick. In the exterior case in which the side wall is provided and the substrate is disposed inside the side wall, it is difficult to integrally form the fitting convex portion in the plastic molding step. This is because there is a side wall in the direction in which the mold for forming the fitting convex portion is removed, and the mold cannot be easily removed. For this reason, a battery pack in which a substrate is directly fitted to an exterior case and placed at an accurate position cannot be manufactured efficiently and inexpensively.

  However, it is important to arrange the substrate at an accurate position with respect to the outer case. In particular, the substrate on which the output terminal is fixed is required to be placed at an accurate position with respect to the outer case. This is because if the relative position between the terminal window of the outer case and the output terminal fixed to the substrate is shifted, the output terminal cannot be arranged on the terminal window. Therefore, it is important that the substrate is disposed at an accurate position with respect to the outer case and that the substrate is not displaced from the outer case.

  The present invention was developed for the purpose of realizing this, and an important object of the present invention is to efficiently and easily mass-produce a substrate while placing the substrate at an accurate position of the outer case. The object is to provide a battery pack that can.

  In the battery pack of the present invention, a thin battery 2 in which the thickness of the battery is thinner than the width of the battery is attached to the plastic outer case 1. The outer case 1 includes a first case 1 </ b> A and a second case 1 </ b> B that are divided on the front and back sides of the thin battery 2. The first case 1 </ b> A and the second case 1 </ b> B are formed in a rectangular frame shape along the side surface and the outside of the end surface of the thin battery 2. The rectangular frame-shaped first case 1 </ b> A has one side serving as a substrate storage portion 25 that stores the substrate 5 inside. The substrate storage unit 25 includes integrally formed side walls 25B protruding inward along both side edges of the main body plate unit 25A facing the battery, and the substrate 5 is disposed between the side walls 25B. ing. The board | substrate 5 has the fitting convex part 26 which protrudes from the side edge. The substrate storage unit 25 is provided with a through hole 27 in the side wall 25 </ b> B for receiving the fitting convex portion 26 of the substrate 5. In the battery pack, the fitting convex portion 26 is inserted into the through hole 27, and the substrate 5 is disposed at a fixed position inside the substrate housing portion 25.

  However, the thickness of the outer case is "almost equal" to the thickness of the thin battery, not only in a state where both match completely, but also in a state where the thin battery is connected to the outer case, the difference is negligible, For example, a state in which the difference is 1 mm or less is included.

  In the first case 1A, the second case 1B can be ultrasonically welded to one side wall 25B, and a through hole 27 into which the fitting convex portion 26 of the substrate 5 is inserted can be provided on the other side wall 25B. Further, the first case 1 </ b> A can be provided by integrally forming the hollow cylinder 20 at both ends of the substrate storage portion 25. The second case 1B can be provided with protruding holding ribs 28 for holding the substrate 5 in a fixed position on the inner surface.

  In the battery pack of the present invention, the output terminal 8 can be fixed to the substrate 5 and the terminal window 13 for exposing the output terminal 8 to the outside can be provided in the substrate housing portion 25 of the first case 1A. Furthermore, in the battery pack of the present invention, the end case portion 1b that covers the end surface on which the convex electrode 10 of the thin battery 2 is provided can be used as the substrate storage portion 25.

  The battery pack of the present invention has an advantage that it can be mass-produced efficiently and easily at a low cost while arranging the substrate at an accurate position of the outer case. In the battery pack of the present invention, the first case having a rectangular frame shape is provided with a substrate housing portion in which side walls are integrally formed on both sides, and a substrate is disposed between the side walls. Since a through hole is provided in the side wall, a fitting convex portion to be inserted into the through hole is provided on the substrate, the fitting convex portion is inserted into the through hole, and the substrate is disposed at a fixed position of the substrate housing portion of the first case. It is. In particular, the battery pack of the present invention is characterized in that the entire outer case is made thin so that the substrate can be firmly fixed so that it does not shift to a fixed position even when the width of the substrate storage portion is reduced. This is because a through hole is provided in the side wall of the substrate storage portion, and a fitting convex portion to be inserted into the through hole is provided in the substrate. The first case with this structure can be efficiently manufactured with a simple mold. This is because the through hole provided in the side wall can be molded by a mold that is removed so as to be pulled out to the outside. For this reason, the battery pack of the present invention has an advantage that the substrate can be firmly fixed so as not to shift to an accurate position while efficiently mass-producing the first case made thin as a whole at low cost.

  Embodiments of the present invention will be described below with reference to the drawings. However, the example shown below illustrates the battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows.

  Further, in this specification, in order to facilitate understanding of the scope of claims, the numbers corresponding to the members shown in the examples are referred to as “the scope of claims” and “the means for solving the problems”. It is added to the member shown by. However, the members shown in the claims are not limited to the members in the embodiments.

  The battery pack shown in FIGS. 3 to 6 includes an outer case 1, a thin battery 2 attached to the outer case 1, and an insulating sheet 7 bonded to the surface of the thin battery 2 and the outer case 1.

  The thin battery 2 is a secondary battery whose thickness is thinner than its width. The thin battery 2 is a lithium ion battery or a polymer battery. The polymer battery is a lithium polymer battery. However, the present invention does not specify a thin battery as a lithium ion battery or a polymer battery. The thin battery may be a battery other than these batteries, for example, a nickel-hydrogen battery or a nickel-cadmium battery.

  The outer case 1 is manufactured by molding an insulating material. The insulating material for molding the outer case 1 is a plastic that can be ultrasonically welded, that is, a thermoplastic plastic. As shown in FIGS. 5 and 6, the outer case 1 is provided with an opening 3 that exposes the front and back surfaces of the thin battery 2 to the outside, and covers the both sides and both end faces of the thin battery 2. It is molded into. The outer case 1 has a side case portion 1a that covers both side surfaces of the thin battery 2 and an end case portion 1b that covers both end surfaces of the thin battery 2 connected to each other at both ends so that the overall shape is a rectangular frame. Yes.

  As shown in the cross-sectional view of FIG. 7, the side surface case portion 1a is provided with holding grooves 4 on the inner surface. The outer case 1 is connected so that the thin battery 2 is inserted into the holding groove 4 of the side case portion 1a so that the thin battery 2 is not detached. In the thin battery 2, the corner portions on both side surfaces are chamfered, the central portion is protruded, and this is inserted into the holding groove 4. The outer case 1 having this structure holds both sides of the thin battery 2 with the side case portion 1a to prevent the thin battery 2 from coming off in the front and back direction as indicated by arrows A and B in the figure. As shown in the cross-sectional view of FIG. 7, the thin battery 2 having the protruding portion in the center of the side surface does not protrude the side case portion 1 a from the front and back surfaces of the thin battery 2 by inserting the protruding portion into the holding groove 4. , Can be prevented from shifting in the front and back direction. The thin battery 2 such as a lithium ion secondary battery or a polymer battery has a shape in which corners are chamfered with both side surfaces curved with a predetermined radius of curvature. Both side surfaces of the thin battery 2 which is a curved surface have a chamfered portion along the corner edge and a protruding portion at the center. For this reason, as a structure in which both side walls of the holding groove 4 are guided to the chamfered portion, the side case 1a can be prevented from protruding from the front and back of the thin battery 2, and the thin battery 2 can be prevented from shifting in the front and back direction. However, the battery pack of the present invention is not necessarily provided with a holding groove in the side case portion, and the both side surfaces of the thin battery are adhered to the inner surface of the side case portion with an adhesive, or adhered with an adhesive, or double-sided. It can also be attached and fixed with tape.

  The outer case 1 is formed so that both the side case portion 1a and the end case portion 1b do not protrude high from the front and back surfaces of the thin battery 2, and the thickness of the outer case 1 is substantially equal to the thickness of the thin battery 2. To do. The exterior case 1 of FIGS. 5 and 6 has a part of the surface of the side case portion 1 a and the end case portion 1 b formed in the same plane as the front and back surfaces of the thin battery 2. The battery pack shown in FIG. 5 and FIG. 6 is provided with a protruding portion 14 at a part of the end case portion 1b where the insulating sheet 7 is not bonded, and the surface of the protruding portion 14 is flush with the insulating sheet 7. It is trying to become. The illustrated battery pack is provided with a linear projecting surface 14A along the outer side of the end case part 1b containing the output terminal 8, and the opposite end case part 1b projects to the outer part excluding the central part. A surface 14A is provided. The insulating sheet 7 is bonded to the inside of the end case portion 1b of the outer case 1 between the projecting surfaces 14A provided on the pair of end case portions 1b. The outer case 1 can be formed to have the same thickness as the thin battery 2 by forming the protruding surface 14 </ b> A thicker than the thin battery 2 corresponding to the thickness of the insulating sheet 7. However, in the battery pack of the present invention, the outer case can be formed thinner than the thin battery, and a part of the outer case can be formed to protrude from the surface of the thin battery. This battery pack can be mounted on an electric device by providing a recess for fitting a portion protruding from the thin battery in the battery mounting portion of the electric device.

  As shown in FIGS. 3 to 6, the exterior case 1 includes a first case 1 </ b> A and a second case 1 </ b> B that are divided on the front and back sides of the thin battery 2. The first case 1A and the second case 1B are separately molded of plastic. Each of the first case 1A and the second case 1B includes a side case portion 1a and an end case portion 1b. The first case 1A and the second case 1B are connected via a locking hook 16 and a locking recess 17, and are further connected by ultrasonic welding.

∵ The first case 1A and the second case 1B are formed by connecting a side case portion 1a along the side surface of the thin battery 2 and an end case portion 1b along the outside of the end surface, and the overall shape is a rectangular frame shape. It is said. The rectangular frame-shaped first case 1 </ b> A has one side serving as a substrate storage portion 25 that stores the substrate 5 inside. In FIG. 5, the first case 1 </ b> A uses the end case portion 1 b located on the lower left side as the substrate storage portion 25. In the first case 1 </ b> A shown in these drawings, the end case portion 1 b that covers the end surface of the thin battery 2 where the convex electrode 10 is provided is used as the substrate storage portion 25. However, in the battery pack of the present invention, the substrate storage portion does not necessarily have to be an end case portion that faces the end surface on which the convex electrode is provided, and the opposite end case portion is the substrate storage portion, or The side case part can also be used as a substrate storage part.

  A perspective view of the first case 1A as viewed from above is shown in FIG. 8, a perspective view of FIG. 8 upside down is shown in FIG. 9, and an exploded cross-sectional view of the exterior case 1 is shown in FIG. As shown in these drawings, the substrate housing portion 25 of the first case 1A is integrally formed with a main body plate portion 25A facing the battery and side walls 25B protruding inward along both side edges, The substrate 5 is disposed between a pair of side walls 25B provided on both side edges.

  The main body plate portion 25 </ b> A is a surface facing the battery end surface on which the convex electrode 10 is provided, and is provided with a terminal window 13. The side walls 25B are provided on both side edges of the main body plate portion 25A in a posture orthogonal to the main body plate portion 25A, that is, in a posture parallel to the front and back surfaces of the thin battery 2. One side wall 25B is provided with a through hole 27 that connects the substrate 5 to a fixed position. The through-hole 27 puts the fitting convex part 26 provided in the board | substrate 5, and arrange | positions the board | substrate 5 in a fixed position. As shown in FIGS. 8 and 9, the through hole 27 is provided so as to penetrate from the inner side to the outer side of the side wall 25B. The side wall 25B in the figure has a through hole 27 at the boundary with the main body plate portion 25A. The substrate storage unit 25 arranges the substrate 5 close to the inner surface. This is because the through hole 27 specifies the position of the substrate 5. In the structure in which the substrate is disposed away from the inner surface of the substrate housing portion, the through hole is opened away from the main body plate portion. The first case 1A shown in the figure has two through holes 27 in the side wall 25B. However, the number of through holes 27 in the side wall 25B may be one, or three or more.

  The other side wall 25 </ b> B of the first case 1 </ b> A is provided with a longitudinal groove 18 for ultrasonically welding and connecting the second case 1 </ b> B. The longitudinal groove 18 is ultrasonically welded with the ridges 19 of the second case 1B.

  The substrate 5 is provided with a fitting convex portion 26 protruding from the side edge. The substrate 5 shown in the figure is provided with two fitting convex portions 26 to be inserted into the through holes 27. The substrate 5 shown in the figure has a fitting convex portion 26 in the vicinity of the terminal window 13, that is, in the vicinity of the output terminal 8. With this structure, the output terminal 8 of the substrate 5 can be disposed so as not to be firmly displaced to a fixed position of the outer case 1. This is because the fitting convex portion 26 put in the through hole 27 prevents the positional deviation of the substrate 5. This is extremely important for preventing poor contact between the output terminal 8 of the battery pack and the power supply terminal of the electric device. This is because the displacement of the output terminal 8 of the battery pack causes contact failure. When the battery pack is attached to the electric device, the power terminal of the electric device is elastically pushed out to the output terminal 8. When the power terminal is pushed and displaced, the output terminal 8 and the power terminal cannot be contacted in a normal state. The output terminal 8 that is not displaced in this state can reliably contact the power supply terminal and effectively prevent poor contact.

  In the outer case 1 of FIG. 10, a holding rib 28 that holds the substrate 5 in a fixed position protrudes from the inner surface of the second case 1B. In the exterior case 1, the fitting convex portion 26 is inserted into the through hole 27 to support one side edge of the substrate 5, and the other side edge of the substrate 5 is supported by the holding rib 28 of the second case 1B. Therefore, the outer case 1 is disposed at a fixed position while supporting both sides of the substrate 5.

  The substrate 5 is formed by molding an insulating material such as plastic into a plate shape. The outer shape of the substrate 5 is substantially equal to or slightly smaller than the outer shape of the main body plate portion 25A of the substrate storage portion 25, and is shaped so as not to protrude from the main body plate portion 25A. The substrate 5 is provided with a pair of output terminals 8 and a communication terminal 24 on the opposite side of the surface facing the battery end surface. The output terminal 8 and the communication terminal 24 are metal plates, and the metal plate that is the output terminal 8 and the communication terminal 24 is fixed to the substrate 5 or sandwiched between the substrate 5 and the outer case 1 and fixed in place. Is done. Each terminal is not limited to a metal plate, and may be one obtained by applying gold plating to a land of a substrate. The terminal plated with gold can reduce the contact resistance. Furthermore, the substrate 5 can also be mounted with an electronic component that mounts a protection circuit that prevents the battery from overcharging, overdischarging, overcurrent, and the like.

  The substrate 5 is disposed inside the substrate housing portion 25 of the first case 1A, and is sandwiched between the inner surface of the end case portion 1b and the battery end surface of the thin battery 2 and fixed in place. An end case portion 1b of the first case 1A constituting the exterior case 1 opens a terminal window 13. The terminal window 13 causes the output terminal 8 fixed to the substrate 5 to be exposed to the outside of the exterior case 1. Accordingly, the terminal window 13 is opened at a position where the substrate 5 is fixed at a fixed position inside the outer case 1 and the output terminal 8 can be exposed to the outside. The substrate 5 built in the outer case 1 is pushed by the thin battery 2 and fixed in place, and the output terminal 8 is accurately placed in place.

  In the battery pack, the pair of output terminals 8 are connected to the positive and negative electrodes of the thin battery 2 via the protective element 12. FIG. 11 shows a circuit diagram of the battery pack. In this battery pack, positive and negative electrodes are connected to a pair of output terminals 8 via a protection element 12. One electrode is connected to the output terminal 8 via a PTC, and the other electrode is connected to the output terminal 8 via a fuse. In the battery pack of this circuit diagram, the output terminal 8 on the positive electrode side is connected to the positive electrode of the thin battery 2 via a fuse, and the output terminal 8 on the negative electrode side is connected to the negative electrode of the thin battery 2 via a PTC. Contrary to this circuit diagram, a PTC and a fuse can be connected. Moreover, both output terminals can be connected to the electrode of the thin battery via a fuse, or can be connected to the electrode of the thin battery via a PTC. The battery pack in which the protective element 12 is connected to both the positive and negative electrodes of the thin battery 2 can be used safely even if the output terminal 8 and the electrode of the thin battery 2 are short-circuited by mistake. This is because, regardless of which electrode of the thin battery 2 is connected to the output terminal 8, the protective element 12 operates to cut off the short current. The battery pack insulates the surfaces of both the outer can and the convex electrode 10. Therefore, a short current does not flow in a normal use state. However, when the insulating sheet 7 covering the surface of the outer can of the thin battery 2 is damaged, or when a metal wire is inserted into the outer case 1 and contacts the convex electrode 10, a short current may flow. . For example, when the outer can of the thin battery 2 and the output terminal 8 on the negative electrode side are connected with a metal, if the insulation of the outer can is incomplete, a short current flows. Further, when a metal wire is inserted between the outer case 1 and the thin battery 2 and this metal wire comes into contact with the output terminal 8 on the positive electrode side, a short current flows. In the battery pack in which the protection element 12 is connected between both the output terminals 8 and the positive and negative electrodes, when a short current flows, this operates to cut off the short current.

  The protection element 12 is built in a storage portion provided in the end case portion 1 b of the outer case 1. The end case portion 1 b is provided with a storage portion for the protection element 12 between the substrate 5 and the thin battery 2, and the protection element 12 is disposed here. However, the protective element can be disposed in a space formed between the side case portion of the outer case and the thin battery.

  The illustrated battery pack includes a protection element 12 as a protection circuit. However, the battery pack has, as a protection circuit, a circuit that detects the current and shuts off the current when an overcurrent flows, a circuit that detects the battery voltage and detects a battery overcharge or overdischarge, and shuts off the current. It can also be built in the outer case. The exterior case in which the protection circuit is built in is provided with a storage chamber for storing the protection circuit, and the protection circuit is built in and insulated from the outside. The protection circuit is realized by mounting electronic components on a printed circuit board. The protection circuit can also be built in the end case part by mounting electronic components on the substrate.

  As shown in FIG. 12, the thin battery 2 is provided with an insulating separator 9 on the battery end surface on which the substrate 5 is provided. Since the substrate 5 is disposed on the battery end surface on which the convex electrode 10 of the thin battery 2 is provided, the insulating separator 9 is also disposed on the battery end surface on which the convex electrode 10 is provided. The insulating separator 9 disposed here is provided with a through hole 11 for projecting the convex electrode 10. The convex electrode 10 is inserted into the through hole 11 and fixed to the battery end face to insulate the battery end face. To do. The insulating separator 9 is bonded and fixed to the battery end surface, or is bonded and fixed to the battery end surface via a double-sided adhesive tape, or is bonded and fixed to the battery end surface via an adhesive layer. The width (W1) of the insulating separator 9 is smaller than the width (W2) of the battery end face. More preferably, the length of the insulating separator 9 is also shorter than the length of the substrate 5. The insulating separator 9 is disposed between the substrate 5 and the battery end face and fixed in place.

  The battery pack in which the insulating separator 9 is disposed on the battery end surface of the thin battery 2 may have a structure in which the insulating separator 9 absorbs a dimensional error in the length of the thin battery 2. In particular, by using a sheet material whose thickness can be elastically deformed for the insulating separator 9, such as a nonwoven fabric, insulating paper, or a rubber-like elastic sheet, the dimensional error of the thin battery 2 can be absorbed by the single insulating separator 9. Moreover, the insulating separator which does not deform | transform elastically can adjust the number of lamination | stacking, and can absorb the dimensional error of a thin battery. However, the battery pack that absorbs the dimensional error of the thin battery 2 with the insulating separator 9 has a structure in which a part or the entire periphery of the insulating separator 9 is sandwiched between the battery end surface and the substrate 5, and the elastic restoring force of the insulating separator 9 is Thus, the substrate 5 is pressed. In the battery pack having this structure, regardless of the size of the thin battery 2, the substrate 5 can be arranged at a fixed position of the outer case 1 and the output terminal 8 can be arranged at an accurate position.

  In the exterior case 1 shown in the figure, a locking hook 16 is formed integrally with a second case 1B positioned above in the figure, and a locking recess 17 for locking the locking hook 16 is the other case. One case 1A is provided. The exterior case 1 shown in the figure is provided with a locking hook 16 in the second case 1B and a locking recess 17 in the first case 1A, but the locking hook is provided in both the second case and the first case. Both the first case and the second case can be provided with a locking recess at a position where the locking hook is locked.

  The locking recess 17 is provided on the outer surface of the outer case 1. However, although not shown, the locking recess can be provided on the inner surface of the outer case. The locking hook 16 is provided so as to protrude from the second case 1B toward the first case 1A so as to be fitted into the locking recess 17. The locking hook 16 has a locking projection 16A that protrudes in the longitudinal direction along the surface of the outer case 1. The exterior case 1 shown in the figure has a pair of locking hooks 16 on the side case portion 1a. In the outer case 1 of FIGS. 5 and 6, a pair of locking hooks 16 are provided with locking projections 16 </ b> A that protrude in opposite directions. In FIG. 5, a locking projection 16A is provided so that the lower left locking hook 16 protrudes to the upper right, and a locking projection 16A is provided so that the locking hook 16 on the upper right side protrudes to the lower left. The locking hook 16 in the figure protrudes in a direction in which the locking projections 16A face each other, but a locking projection can also be provided so as to protrude on the opposite side to this drawing. The structure in which the locking projections 16A protruding in the opposite direction are provided on the pair of locking hooks 16 has a feature that the first case 1A and the second case 1B can be firmly connected without being laterally displaced. However, although not shown, the locking projections can be provided on the plurality of locking hooks so that the locking projections protrude in the same direction. Also, a locking projection can be provided at the tip of the locking hook so as to protrude on both sides. In the illustrated locking hook 16, the locking projection 16 </ b> A has a quadrangular shape, but the locking projection can be a triangle, or a shape that follows an arc or an elliptical arc.

  The locking hook 16 is elastically deformed when entering the locking recess 17. The locking hook 16 shown in the drawing is formed into a thin plate shape along the surface of the outer case 1 so that it can be elastically deformed without difficulty. In the outer case 1, the locking hook 16 is fitted into the locking recess 17 and locked, and the second case 1B and the first case 1A are connected. Further, the first case 1A and the second case 1B are joined together by ultrasonic welding of surfaces that are in contact with each other.

  The exterior case 1 shown in the figure connects the first case 1A and the end case 1b of the second case 1B by ultrasonic welding. The end case portions 1b of the first case 1A and the second case 1B are simply and reliably connected to each other by ultrasonic welding of the opposing surfaces. In particular, the outer case 1 manufactured by connecting the second case 1B and the first case 1A with the locking hook 16 and the locking recess 17 and ultrasonically welding the end case portion 1b is before ultrasonication. In the process, the first case 1A and the second case 1B are connected to an accurate position. For this reason, the outer case 1 having this structure needs to be ultrasonically welded by temporarily fixing the second case 1B and the first case 1A to an accurate position by using another jig or the like when performing ultrasonic welding. There is no. Therefore, the second case 1B and the first case 1A can be easily and easily connected efficiently so as not to be displaced, and can be mass-produced at low cost.

  As shown in the cross-sectional view of FIG. 10, the opposing surface of the end case portion 1 b to be ultrasonically welded is provided with a vertical groove 18 on one side, and a ridge 19 that can be put in the vertical groove 18 on the other side. This structure is ultrasonically welded in a state where the ridges 19 are put in the longitudinal grooves 18, and is welded and connected so as not to separate more reliably. However, the first case and the second case can be connected by bonding the opposing surfaces.

  5A and 8B, the first case 1A protrudes inwardly at the corners of the end case portion 1b and the side case portion 1a, that is, at both ends of the end case portion 1b, so that the hollow cylinder 20 is integrally formed. Molded and provided. The hollow cylinder 20 has a rectangular tube shape. The exterior case 1 in which the hollow cylinder 20 is provided at the corners of the end case part 1b and the side case part 1a can increase the impact strength at the corners. This is because the hollow cylinder 20 acts as a buffer material that absorbs the impact received at the corners. In particular, since the hollow cylinder 20 is not filled with plastic, it is easily deformed and has an excellent buffering action. Further, the first case 1A having this structure can be used in combination with the portion where the hollow case 20 is accurately positioned and connected to the second case 1B and the first case 1A. In order to realize this, the second case 1B is provided with a positioning convex portion 21 to be inserted into the hollow cylinder 20, as shown in FIG. This exterior case 1 can connect the 2nd case 1B and 1st case 1A to an exact position by putting the positioning convex part 21 in the hollow cylinder 20. FIG. In particular, the second case 1 </ b> B and the first case 1 </ b> A can be more accurately connected by a structure in which the locking hook 16 is locked in the locking recess 17 and the positioning protrusion 21 is inserted in the hollow cylinder 20. Furthermore, the structure which provides the hollow cylinder 20 in the both ends of the end case 1b which is the board | substrate storage part 25 inserts the board | substrate 5 between the hollow cylinders 20 arrange | positioned at both ends, and the shift | offset | difference of the board | substrate 5 in the left-right direction is carried out. Can be prevented. Therefore, the interval between the hollow cylinders 20 arranged at both ends is made substantially equal to the entire length of the substrate 5 or slightly larger within a range in which the substrate 5 is not displaced.

  As shown in FIGS. 5 and 6, the battery pack has a thin battery 2 disposed between the first case 1A and the second case 1B, and as shown in FIG. 4, the first case 1A and the second case 1B. Then, as shown in FIGS. 3 and 4, the insulating sheet 7 is bonded so as to cover both the front and back surfaces of the thin battery 2 and a part of the outer case 1. The insulating sheet 7 is a label having an adhesive layer on the inner surface. However, the insulating sheet can be a plastic sheet, which can be bonded to the surface of the thin battery with an adhesive. As shown in FIGS. 3 and 4, the insulating sheet 7 is adhered so as to cover the entire surface of the opening 3 of the outer case 1, and the entire surface of the outer can of the thin battery 2 exposed to the outside of the outer case 1. Insulate. This structure can insulate the outer can using the thin battery 2 of the outer can whose surface is not insulated.

  However, in the battery pack of the present invention, as shown by cross-hatching in FIG. 13, a plastic protective film 22 is attached so as to cover a part of the thin battery 2 and the outer case 1, and the surface of the thin battery 2 is covered. In addition to insulation, the outer case 1 can be connected to the thin battery 2. In addition, an insulating sheet can be further bonded to the surface provided with the plastic protective film, so that the plastic protective film and the insulating sheet can be double insulated. The insulating sheet does not necessarily need to cover the entire surface of the thin battery. In particular, a thin battery in which the outer can surface is covered with an insulating material can be insulated without being covered with an insulating sheet. In addition, a battery pack used by being mounted inside an electric device does not necessarily need to insulate the entire surface of the thin battery, and an insulating sheet can be adhered so that a part of the thin battery is exposed to the outside. . The insulating sheet 7 has characters, figures, etc. printed on its surface.

  The insulating sheet 7 covers the surface of the thin battery 2 and connects the first case 1A and the second case 1B. The insulating sheet 7 is bonded to the surface of the thin battery 2 and is also bonded to the side case portions 1a of the first case 1A and the second case 1B. The first case 1A and the second case 1B are connected by ultrasonic welding of the end case 1b, but are not connected by ultrasonic welding of the side case 1a. The battery pack shown in the exploded perspective view of FIG. 4 has a side case portion 1a of the first case 1A and the second case 1B on one side of the thin battery 2, that is, both side portions of one insulating sheet 7 bonded to the upper surface in the figure. Are adhered to the outer surface of the thin battery 2 and the back surface of the thin battery 2.

  Further, the insulating sheet 7 is provided so as to protrude the adhesive piece 7A, and the adhesive piece 7A is adhered to the surface of the end case portion 1b covering the bottom surface of the thin battery 2. The adhesive piece 7A is adhered between the projecting surfaces 14A provided on one end case portion 1b, and is adhered to the back surface of the thin battery 2 from the end case portion 1b. The insulating sheet 7 is firmly bonded to both sides and the bottom side of the thin battery 2. In FIG. 4, the insulating sheet 7 bonded to the back surface of the thin battery 2 is bonded only to the back surface that is one surface of the thin battery 2. However, this insulating sheet can be adhered to one surface of the thin battery, and the periphery thereof can be further adhered to the surface of the exterior case.

  As shown in the sectional view of FIG. 7, the outer case 1 has an outer corner portion of the side case portion 1 a as a curved surface 15. The side case portion 1a in the figure has a radius of curvature of the curved surface 15 provided at the corner portion larger than the thickness (d) of the side case portion 1a and smaller than half the thickness (D) of the thin battery 2. ing. However, the side case part 1a can also make the curvature radius of the curved surface provided in the corner part equal to the thickness of the side case part 1a. In the exterior case 1 of FIG. 4, the protruding surface 14A is provided on a part of the end case portion 1b, and the insulating sheet 7 is bonded between the protruding surfaces 14A. It is said. The insulating sheet 7 is bonded to the surface of the outer side surface of the side case portion 1a of the first case 1A and the second case 1B having the curved surface 15 at the corner portion, and connects the first case 1A and the second case 1B. ing. The side case portion 1a of the outer case 1 connected by the insulating sheet 7 is connected by inserting the locking hook 16 into the locking recess 17 and being firmly connected by the insulating sheet 7 without ultrasonic welding. Therefore, in the battery pack, only the end case portion 1b of the first case 1A and the second case 1B is connected by ultrasonic welding, and the side case portion 1a is locked without ultrasonically welding the side case portion 1a. The hook 16 and the locking recess 17 are connected, and further the insulating sheet 7 is connected.

  Since the side case 1a of FIGS. 4 and 7 has a curved surface 15 at the corner, the insulating sheet 7 can be in close contact with the surface such that there is no gap.

  Furthermore, as shown in the cross-sectional view of FIG. 7, the battery pack has a tamper-proof label 23 bonded to the surface of the side case portion 1a. The insulating sheet 7 is laminated and adhered to the surface of the tamper-proof label 23. The tamper-proof label 23 is a label for displaying that, for example, characters are transferred and peeled when the user peels off the insulating sheet 7. The tamper-proof label 23 adhered here connects the side case 1a of the first case 1A and the second case 1B more firmly. Further, the tamper-proof label 23 can be adhered without increasing the thickness of the battery pack.

It is a disassembled perspective view of the conventional battery pack. It is a perspective view of the holder of the battery pack shown in FIG. It is a perspective view of the battery pack concerning one Example of this invention. FIG. 4 is an exploded perspective view of the battery pack shown in FIG. 3. It is a disassembled perspective view of the exterior case shown in FIG. It is a bottom perspective view of the exterior case shown in FIG. FIG. 4 is a cross-sectional view taken along line AA of the battery pack shown in FIG. It is a perspective view which shows the state which mounts a board | substrate to a 1st case. It is the figure which turned the 1st case shown in FIG. 8 upside down, Comprising: It is a perspective view which shows the 1st case with which the board | substrate was mounted | worn. It is an exploded sectional view of an exterior case, and is a sectional view showing a substrate storage part. FIG. 4 is a circuit diagram of the battery pack shown in FIG. 3. It is a disassembled perspective view which shows a thin battery and an insulation separator. It is a perspective view of the battery pack concerning the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Exterior case 1A ... 1st case 1B ... 2nd case
DESCRIPTION OF SYMBOLS 1a ... Side surface case part 1b ... End part case part 2 ... Thin battery 3 ... Opening part 4 ... Holding groove 5 ... Substrate 7 ... Insulating sheet 7A ... Adhesive piece 8 ... Output terminal 9 ... Insulating separator 10 ... Convex electrode 11 ... Through Hole 12 ... Protective element 13 ... Terminal window 14 ... Projection 14A ... Projection surface 15 ... Curved surface 16 ... Lock hook 16A ... Lock projection 17 ... Lock recess 18 ... Vertical groove 19 ... Projection strip 20 ... Hollow tube 21 ... Positioning convex part 22 ... Plastic protective film 23 ... Falsification preventing label 24 ... Communication terminal 25 ... Substrate housing part 25A ... Main body plate part 25B ... Side wall 26 ... Fitting convex part 27 ... Through hole 28 ... Retaining rib 41 ... Exterior case 41A ... 1st case 41B ... 2nd case 42 ... Thin battery 43 ... Substrate 44 ... Holder 45 ... Fitting convex part 46 ... Fitting concave part 47 ... Output terminal

Claims (6)

In a battery pack in which a thin battery (2) whose thickness is smaller than the width of the battery is mounted on a plastic outer case (1),
The outer case (1) includes a first case (1A) and a second case (1B) which are divided on the front and back sides of the thin battery (2), and the first case (1A) and the second case (1B). ) Is formed into a rectangular frame shape along the outside of the side and end faces of the thin battery (2),
The rectangular frame-shaped first case (1A) has a substrate storage portion (25) for storing the substrate (5) on one side, and this substrate storage portion (25) is a body plate facing the battery. The side wall (25B) protruding inward along the both side edges of the part (25A) is integrally formed, and the substrate (5) is disposed between the side walls (25B),
The substrate (5) has a fitting convex portion (26) protruding from the side edge thereof, and a through hole (27) for inserting the fitting convex portion (26) into the side wall (25B) of the substrate storage portion (25). The battery pack is formed by inserting the fitting convex portion (26) into the through hole (27) and arranging the substrate (5) at a fixed position inside the substrate housing portion (25).   The first case (1A) ultrasonically welds the second case (1B) to one side wall (25B) and inserts the fitting convex part (26) of the substrate (5) into the other side wall (25B). The battery pack according to claim 1, wherein a hole (27) is provided.   The battery pack according to claim 1, wherein the first case (1A) is formed by integrally forming a hollow cylinder (20) at both ends of the substrate storage portion (25).   The battery pack according to claim 1, wherein a holding rib (28) for holding the substrate (5) in a fixed position protrudes from an inner surface of the second case (1B).   A terminal window (13) for fixing the output terminal (8) to the board (5) and exposing the output terminal (8) to the outside is provided in the board housing part (25) of the first case (1A). The battery pack according to claim 1. 2. The battery pack according to claim 1, wherein an end case portion (1 b) that covers an end surface on which the convex electrode (10) of the thin battery (2) is provided is a substrate storage portion (25).

Images