JP2008210735A - Battery pack, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack capable of improving a production yield while downsizing itself. <P>SOLUTION: The battery pack 10 includes a battery 1, a circuit board 5, and an end case 6, wherein the end case 6 is fixed to one end surface 3 of the battery 1 through connection pins 12 with the circuit board 5 housed therein. Specifically, recessed parts 3a are formed on the one end surface 3 of the battery 1, and through-holes 11 communicating with openings of the recessed parts 3a are formed on the end case 6. The connection pins 12 penetrates the through-holes 11 so that tips thereof exist in the recessed parts 3a, and is fixed to the inside surfaces of the recessed parts 3a and the inside surfaces of the through-holes 11. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a battery pack and a battery pack manufacturing method, and more particularly to a secondary battery pack and a secondary battery manufacturing method.

  Secondary batteries such as nickel metal hydride batteries and lithium ion secondary batteries are generally integrated with a circuit board having a charge / discharge circuit and are distributed in the market as battery packs. Such a battery pack is required to be compact, to have a low connection resistance with an electric device or the like, to have a high reliability of the connection portion, and to be able to be manufactured with a high yield.

For example, in the battery pack disclosed in Patent Document 1, the circuit board is sandwiched between the end case and the one end surface of the battery, and the end case is fixed to the one end surface of the battery via screws.
Japanese Patent Laid-Open No. 2006-164551

  In order to make the battery pack compact, it is preferable to fix the end case to the battery using a small-diameter screw. However, as the diameter of the screw becomes smaller, the probability of screw fastening failure increases, leading to a decrease in the manufacturing yield of the battery pack. Therefore, there is a demand for a battery pack that improves the manufacturing yield while reducing the size of the battery pack.

  This invention is made | formed in view of this point, The place made into the objective is providing the manufacturing method of the battery pack which aims at the improvement of a manufacturing yield, aiming at the compactization of a battery pack.

  The battery pack of the present invention includes a battery having a recess formed on one end surface, an end case formed with a through hole that covers one end surface of the battery and communicates with the opening of the recess, and the tip is present in the recess. And a coupling pin fixed to the inner surface of the through hole and the inner surface of the recess.

  In the preferred embodiment described below, the coupling pin is bonded to the inner surface of the through hole and the inner surface of the recess through an adhesive, and in another preferred embodiment described later, to the inner surface of the through hole and the inner surface of the recess. It is fixed.

  The battery pack manufacturing method of the present invention includes a step of preparing a battery having a recess formed on one end face and an end case having a through hole, and an end case so that the through hole communicates with the opening of the recess. Covering the one end surface of the battery, inserting the coupling pin into the through-hole until the pin tip passes through the through-hole and exists in the recess, and fixing the coupling pin to the inner surface of the recess and the inner surface of the through-hole. A fixing step.

  In a preferred embodiment to be described later, in the fixing step, the bonding pin is bonded to the inner surface of the recess and the inner surface of the through hole using an adhesive.

  In another preferred embodiment to be described later, in the fixing step, the coupling pin, the inner surface of the recess, and the inner surface of the through hole are welded to each other. In this case, welding may be performed using a resistance welding method, or welding may be performed using an ultrasonic welding method.

  According to the present invention, it is possible to improve the manufacturing yield of battery packs while reducing the size of the battery pack.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, substantially the same members are denoted by the same reference numerals, and the description thereof may be omitted.

Embodiment 1 of the Invention
FIG. 1 is a perspective view illustrating an appearance of the battery pack according to the first embodiment, and FIG. 2 is an exploded perspective view illustrating a configuration of the battery pack according to the present embodiment.

  The battery pack 10 according to the present embodiment is integrally fixed to the battery 1 with the end case 6 accommodating the circuit board 5. Further, the battery pack 10 has an exterior label 27 wound around and adhered to the peripheral side surface of the battery 1 and a nail hook (not shown), and the end case 6 so as to open the connection windows 8, 8, 8. It is glued to. Here, the nail hook is provided on the lower surface of the battery 1 and is used to hook a nail when the battery pack 10 is attached to or detached from a terminal device or the like.

  As shown in FIG. 2, the battery 1 in the present embodiment is a rectangular battery having a flat cross-sectional shape, or a rounded rectangular or oval rectangular battery. The battery 1 is, for example, a lithium ion battery, and an electrode plate group (not shown) and an electrolytic solution (not shown) as power generation elements are accommodated in the battery case 2 of the battery 1. The electrode plate group is configured to be laminated in multiple layers by winding, for example, with a separator interposed between a belt-like positive electrode plate and a negative electrode plate. The positive electrode plate is configured by applying and drying a positive electrode mixture on a core material made of aluminum foil, for example, and the negative electrode plate is formed by applying and drying a negative electrode mixture on a core material made of copper foil, for example. For example, it is composed of a microporous polypropylene film or the like.

  An electrode terminal 4 protrudes from the longitudinal center of the one end surface 3 of the battery 1. The electrode terminal 4 seals and penetrates the one end surface 3 of the battery case 2 in an insulated state, and is the electrode terminal of the negative electrode of the battery 1. The electrode terminal of the positive electrode of the battery 1 is the battery case 2.

  The circuit board 5 is arrange | positioned on the end surface 3 of the battery 1, and has a charging / discharging safety circuit (not shown). The end case 6 is disposed on the circuit board 5, and is fixed on the one end surface 3 of the battery 1 with the circuit board 5 accommodated therein. Three connection windows 8, 8, 8 are formed at one end side in the longitudinal direction of the end case 6 so as to be spaced from each other, and each connection window 8 has an upper surface and a side surface on one end side of the end case 6. It is formed so that it may open over. The external connection terminals 7 are arranged so as to face each connection window 8, and a pair of connection legs 7 a project downward from each external connection terminal 7, and each connection leg 7 a is connected to each circuit board 5. It is inserted into the connection hole 9 and soldered to the circuit board 5. Here, the external connection terminals 7, 7, 7 are connected and disconnected by inserting / removing the connection terminal of the connection partner, two of the three are external connection terminals of the positive electrode and the negative electrode, and the remaining 1 One is a connection terminal for identification resistance detection.

  FIG. 3 is an enlarged cross-sectional view showing a fixed state between the battery 1 and the end case 6 in the present embodiment. In FIG. 3, the external connection terminals 7, 7, 7 and the connection windows 8, 8, 8 are omitted.

  As shown in FIG. 3, the end case 6 is fixed to the one end surface 3 of the battery 1 via the coupling pins 12 and 12 and the adhesive 31. Specifically, recesses 3 a and 3 a are formed at both ends in the longitudinal direction of the one end surface 3 of the battery 1, respectively. Further, at both ends in the longitudinal direction of the end case 6, through holes 11, 11 are formed so as to penetrate from the outer surface to the inner surface of the end case 6, and each through hole 11 is formed at the opening of each recess 3a. Communicate. Each coupling pin 12 passes through each through hole 11, and the tip 12 b of each coupling pin 12 exists in each recess 3 a. Each coupling pin 12 is bonded to the inner surface of each through-hole 11 and the inner surface of each recess 3 a via an adhesive 31. As the coupling pin, it is preferable to use a coupling pin 12 having a head 12a as shown in FIG. This is because when the coupling pin 12 having the head 12a is used, the coupling pin 12 can be positioned in the through hole 11 by providing a step in the through hole 11.

  By fixing the end case 6 to the one end surface 3 of the battery 1 using the coupling pins 12 and 12 in this manner, the battery pack is compared with the case where the end case is fixed to the one end surface of the battery using screws. 10 production yield can be improved, and the production cost and production time can be reduced. The reason is as follows.

  When fixing using a screw, before inserting a screw in a through-hole, the screw groove corresponding to the screw thread of a screw is formed in the inner surface of a through-hole. However, in order to reduce the size of the battery pack, it is preferable to reduce the diameter of the screw. The smaller the diameter of the screw, the smaller the diameter of the through hole. Therefore, it is difficult to previously form a screw groove on the inner surface of the through hole. Become. When it is difficult to form a screw groove on the inner surface of the through hole in this way, it is preferable to take a method of inserting the screw while rotating the screw into the through hole in which the screw groove is not formed on the inner surface. A screw groove is formed on the inner surface of the hole, and at the same time, the screw is fixed in the through hole.

  However, when screwing using such a method, the screw traveling direction (screw insertion direction into the through hole) is set to a certain direction (specifically, the through hole penetration direction) during screw rotation. It must be maintained, but it is difficult to rotate a small diameter screw without shifting the axis. Therefore, when a small-diameter screw is screwed using such a method, the screw bites into the battery and the end case, and abnormal pressure is applied to the battery and the end case. As a result, the battery and the end case may be destroyed, leading to a manufacturing yield of the battery pack.

  Further, when the end case is fixed to one end surface of the battery using a screw, if the head of the screw is exposed, the screw can be easily removed using a screwdriver or the like. When the screw is removed, the end case is detached, so that the battery pack is disassembled, which is very dangerous. For this reason, it is preferable to hide the screw head using a cover member or the like, which increases the manufacturing cost and manufacturing time of the battery pack.

  On the other hand, when the end case 6 is fixed to the one end surface 3 of the battery 1 using the coupling pins 12 and 12, the coupling pins 12 and 12 may be inserted into the through holes 11 and 11, respectively. In other words, even when a small-diameter coupling pin is used, the coupling pin 12 does not have to be inserted into each through-hole 11 while rotating. Therefore, each coupling pin 12 can be inserted into each through hole 11 without using a special device.

  Further, when the end case 6 is fixed to the one end surface 3 of the battery 1 using each coupling pin 12, even if the head 12a of each coupling pin 12 is exposed, each coupling pin 12 has an adhesive 31 or the like. Since it is being fixed to the inner surface of each through-hole 11 and the inner surface of each recessed part 3a through, it cannot be removed easily even if it uses a driver etc. Therefore, the head 12a of each coupling pin 12 does not have to be hidden using a cover member or the like. As described above, in the battery pack 10 according to the present embodiment, the manufacturing yield can be improved and the manufacturing cost and the manufacturing time can be reduced as compared with the case where the end case is fixed to one end surface of the battery using screws. Can be achieved.

  Furthermore, by forming the recesses 3 a and 3 a on the one end surface 3 of the battery 1, the safety of the battery pack 10 can be improved. The reason is shown below using FIG. 3 and FIG.

  4A and 4B are both enlarged cross-sectional views when the end case 6 is fixed to the one end surface 73 when the one end surface 73 of the battery 71 is flat.

As shown in FIG. 4A, when a pin 72 having a pin length L ₁ longer than the depth L ₂ of the through hole 11 is used as a connecting pin, a part of the connecting pin 72 protrudes from the outer surface of the end case 6. End up. When an external force or impact is applied to a portion of the coupling pin 72 that protrudes from the outer surface of the end case 6, the coupling pin 72 is pulled out of the through hole 11 or the coupling pin 72 is broken. The battery 1 is detached. Therefore, in the case shown in FIG. 4A, the battery pack may be disassembled when an impact such as dropping is applied to the battery pack, which is very dangerous.

For binding the pin to avoid protrude from the outer surface of the end casing portion 6, as shown in FIG. 4 (b), the pin length L ₁ is shorter than the depth L ₂ of the through-holes 11 as attachment pins Pin 82 may be used. However, as shown in FIG. 4B, the tip of the coupling pin 82 does not come into contact with the one end surface 73 of the battery 71, so that the coupling pin 82 is easily detached. Therefore, even in the case shown in FIG. 4B, when an impact such as dropping is applied to the battery pack, the battery pack is disassembled.

Furthermore, even when shown in FIG. 4 (a), even if shown in FIG. 4 (b), also, the pin length L ₁ is substantially the same as the depth L ₂ of the through hole as a coupling pin Even when a certain pin is used (not shown), for example, when a lateral external force is applied to the battery 1, the battery 1 may move according to the external force. From the above, if the one end surface 73 of the battery 71 is flat, the battery pack may be disassembled during use of the battery pack, which is very dangerous.

  On the other hand, when each recessed part 3a is formed in the one end surface 3 of the battery 1 as shown in FIG. 3, each coupling pin 12 is arrange | positioned so that the front-end | tip 12b of each coupling pin 12 exists in the recessed part 3a. be able to. Therefore, it is possible to prevent a part of the coupling pin 72 from protruding from the outer surface of the end case 6 as shown in FIG. 4A. Further, the lateral force in FIG. Even if added to either one, the battery 1 and the end case 6 can be prevented from being displaced from each other. Therefore, since the battery pack 10 can be prevented from being disassembled even when an impact such as dropping is applied to the battery pack 10, the safety of the battery pack 10 can be improved as compared with the case where the one end surface of the battery is flat. Can do.

  Here, the shape of each recessed part 3a is not limited to the shape shown in FIG. For example, each recess 3a may be polygonal in cross section or circular in cross section. Moreover, each recessed part 3a may be columnar shape with which the bottom face was rounded.

  Moreover, the depth of each recessed part 3a should just be 0.9 mm or more, it is preferable if it is 1.0 mm or more, and it should just be 1.2 mm or less. In other words, the depth of each recess 3a may be 60% or more, preferably 80% or more, and 100% or less with respect to the depth of each through-hole 11.

  Moreover, the length of the part which exists in each recessed part 3a among each coupling pin 12 should just be 80% or more of the depth of each recessed part 3a, and should be 90% or more of the depth of each recessed part 3a. More preferably, it is 100% of the depth of each recess 3a. Here, it is assumed that the thickness of the adhesive 31 in each recess 3a is not taken into consideration.

  Further, in order to firmly fix the end case 6 to the battery 1, it is preferable to use an instantaneous adhesive mainly composed of a cyanoacrylate resin as the adhesive 31.

  Here, an electrical connection configuration in the battery pack 10 will be described.

  The positive battery case 2 is connected to the circuit board 5 via a first connection bracket 13 and a connection plate 14. Specifically, the first connection bracket 13 is disposed under the circuit board 5 and has a main body and a rising portion 13a. The main body of the first connection bracket 13 is fixed to the one end surface 3 of the battery 1 by welding. The rising portion 13 a is formed so as to rise from the main body, and is in contact with the inner surface on one end side of the end case 6.

  The connection plate 14 is disposed on the circuit board 5 and is provided on the inner side (front side in FIG. 2) of the rising portion 13a so as to contact the rising portion 13a of the first connection bracket 13. It is supported by a support wall (not shown) of the part case 6. In other words, a support wall is provided in the end case 6, and the connection plate 14 and the rising portion of the first connection bracket 13 are provided between the support wall and the inner surface on one end side of the end case 6. 13a are arranged in order. A connecting leg 14 a is provided on the connecting plate 14 so as to protrude downward from the lower end thereof, and the connecting leg 14 a is fitted into a connecting portion 15 that is recessed in one end of the circuit board 5. Soldered to the connection electrode formed on the lower surface of the portion 15.

  Furthermore, a working opening (not shown) is formed in a portion (a portion indicated by an arrow A in FIG. 2) of the end case 6 that faces the rising portion 13a. A pair of welding electrodes (not shown) are inserted through the working opening and pressed against the rising portion 13a of the first connection bracket 13, and a welding current is passed between the pair of welding electrodes, whereby the rising portion 13a and the connection plate 14 are connected. They are fixed to each other and electrically connected.

  The negative electrode terminal 4 is connected to the circuit board 5 via a safety protection element (such as a temperature fuse or a PTC element) 16, a second connection bracket 17, and a third connection bracket 18. Specifically, the safety protection element 16 is disposed under the circuit board 5 and has an element portion, a first connection piece 16a, and a second connection piece 16b. The first connection piece 16 a is welded to one end of the element portion and is welded to the electrode terminal 4. The second connection piece 16b is welded to the other end of the element portion (the side opposite to the first connection piece 16a).

  The second connection bracket 17 is welded to the second connection piece 16b of the safety protection element 16, and has a main body and a rising portion 17a formed so as to rise from the main body.

  The third connection bracket 18 includes a main body and a rising portion 18a formed so as to rise from the main body. The main body is welded to the upper surface of the circuit board 5, and the rising portion 18a is disposed on the inner side (front side in FIG. 2) of the rising portion 17a so as to contact the rising portion 17a of the second connection bracket 17. . The rising portions 17a and 18a are welded to each other by inserting a pair of welding electrodes from a working hole 19 formed in the end case 6 and flowing a welding current between the pair of welding electrodes.

  Further, a first insulating plate 20 is disposed between the one end surface 3 of the battery 1 and the safety protection element 16, and a second insulating plate 25 is disposed between the safety protection element 16 and the circuit board 5. ing.

  The first insulating plate 20 is fixed to the one end surface 3 of the battery 1 via an adhesive. A through opening 21 is formed in the first insulating plate 20, and the electrode terminal 4 is inserted through the through opening 21. A heat transfer opening 22 is formed in a portion of the first insulating plate 20 facing the element portion of the safety protection element 16, and the heat transfer opening 22 is filled with silicon (not shown). . Thereby, the heat of the battery 1 is effectively transmitted to the element portion of the safety protection element 16. Furthermore, the adhesive 23 is provided in the part which opposes the other end connection piece 16b of the safety protection element 16 among the 1st insulating plates 20, and the 1st insulation board 20 is connected to the other end connection piece via the adhesive material 23. It is adhered to 16b.

  The second insulating plate 25 is bonded to the safety protection element 16 via an adhesive (not shown), thereby ensuring insulation between the safety protection element 16 and the circuit board 5.

  FIG. 5A and FIG. 5B are cross-sectional views showing a part of the manufacturing process of the battery pack 10 according to the present embodiment. 5A and 5B show the external connection terminals 7, 7, 7 and the connection windows 8, 8, 8 formed in the end case 6, and the first, second, and third. The connection brackets 13, 17, 18, the connection plate 14, the safety protection element 16, and the first and second insulating plates 20, 25 are omitted.

  First, although not shown, the battery 1 is prepared. At this time, on one end surface 3 of the battery 1, concave portions 3a and 3a are formed at both ends in the longitudinal direction, respectively, and an electrode terminal 4 is projected from the center in the longitudinal direction. Then, the electrode terminal 4 is fitted into the through opening 21 of the first insulating plate 20, and the first insulating plate 20 is bonded to the one end surface 3 of the battery 1.

  Next, although not shown, the second connection bracket 17 is welded to the connection piece 16 b at the other end of the safety protection element 16. Then, the heat transfer opening 22 of the first insulating plate 20 is filled with silicon, the element portion of the safety protection element 16 is bonded to the heat transfer opening 22, and the connection piece 16 a at one end of the safety protection element 16 is attached to the electrode terminal 4. Weld. In addition, the first connection bracket 13 is welded to the first insulating plate 20, and the main body of the first connection bracket 13 is disposed in substantially the same plane as the first insulating plate 20.

  Subsequently, although not shown, a second insulating plate 25 is bonded onto the main body of the safety protection element 16 and the first connection bracket 13.

  Subsequently, although not shown, each external connection terminal 7 is arranged at a position facing each connection window 8. Then, the connection plate 14 is disposed at a predetermined position in the end case 6. Specifically, it is closer to the work opening provided in the end case 6 (in the vicinity of the arrow A shown in FIG. 2) than the support wall (not shown) for supporting the connection plate 14 provided in the end case 6. The connecting plate 14 is disposed on the surface.

  The third connection bracket 18 is welded to a predetermined position on the circuit board 5. Specifically, after assembling the battery pack, the third connection bracket 18 is placed on the circuit board 5 so that the rising portion 17a of the second connection bracket 17 is provided outside the rising portion 18a of the third connection bracket 18. Weld to.

  Subsequently, although not shown, the circuit board 5 is inserted from the lower end opening of the end case 6. At this time, the circuit board 5 is connected to the end case 6 so that the connection leg 7 a of the external connection terminal 7 protrudes from the connection hole 9 of the circuit board 5 and the connection leg 14 a of the connection plate 14 protrudes from the connection part 15. Place in. And the part which protruded from the connection hole 9 among the connection legs 7a is soldered to the electrode formed in the circumference | surroundings of the connection hole 9. FIG. Further, a portion of the connection leg 14 a that protrudes from the connection portion 15 is soldered to an electrode formed around the connection portion 15.

  Subsequently, although not shown, the rising portion 13a of the first connection bracket 13 is superimposed on the outside of the connection plate 14, and the rising portion 17a of the second connection bracket 17 is outside the rising portion 18a of the third connection bracket 18. To overlay. A nail hook (not shown) is bonded to the other end surface of the battery 1 (the surface opposite to the one end surface 3).

  Subsequently, the end case 6 is fixed to the one end surface 3 of the battery 1. In this embodiment, first, as shown in FIG. 5A, the end case is formed so that the through holes 11 formed in the end case 6 communicate with the openings of the recesses 3a, 3a of the battery 1, respectively. 6 is placed on one end surface 3 of the battery 1.

  Subsequently, as shown in FIG. 5B, a softened adhesive (for example, a molten adhesive) 31 is injected into each through-hole 11.

  Subsequently, each coupling pin 12 is inserted into each through hole 11. At this time, since the adhesive 31 is in a softened state, it is pushed into the space between each coupling pin 12 and the inner surface of each through-hole 11 as each coupling pin 12 is inserted into each through-hole 11. And each coupling pin 12 is inserted in each through-hole 11 until the front-end | tip 12b of each coupling pin 12 is arrange | positioned in each recessed part 11, and the adhesive agent 31 is solidified after that. Thereby, as shown in FIG. 3, each coupling pin 12 is adhere | attached on the inner surface of each through-hole 11, and the inner surface of each recessed part 3a. In this way, the end case 6 can be fixed to the one end surface 3 of the battery 1.

  Subsequently, although not shown, a pair of welding electrodes are inserted from both sides of the working hole 19 of the end case 6 and a welding current is passed between the pair of welding electrodes after pressing. Thereby, the rising portion 17a of the second connection bracket 17 and the rising portion 18a of the third connection bracket 18 are welded to each other. Although not shown, from the work opening of the end case 6 (from the direction of the arrow A shown in FIG. 2), a pair of welding electrodes are inserted and brought into contact with the rising portion 13a of the first connection bracket 13, After pressing, a welding current is passed between the pair of welding electrodes. Thereby, the 1st connection bracket 13 and the connection board 14 are welded mutually.

  Subsequently, although not shown, an exterior label 27 in which an adhesive is applied to the back surface of the synthetic resin sheet is wound around the peripheral side surface of the battery 1 and the periphery of the nail hook, and the connection windows 8, 8 and 8 are opened. Wrap it around the outer surface of the end case 6. Thereby, the opening of each through-hole 11, the opening of the working hole 19, and the working opening of the end case are sealed, and the battery pack shown in FIG. 1 can be manufactured.

  As described above, in the battery pack 10 according to the present embodiment, the manufacturing yield of the battery pack can be improved as compared with the case where the end case is fixed to one end surface of the battery using screws. The pack can be manufactured at low cost and in a short time. In addition, in the battery pack 10 according to the present embodiment, the end case 6 can be firmly fixed to the battery 1 as compared with the case where the end case is fixed to a flat one end surface. Can be improved.

  In the present embodiment, as for the adhesive, it is preferable to use an instantaneous adhesive mainly composed of a cyanoacrylate resin as described in the first embodiment, but other adhesives may be used. .

  Further, when the end case is fixed to one end surface of the battery, the bonding pin is inserted into the through hole after the molten adhesive is inserted into the recess, but the order is not particularly limited. For example, the coupling pin may be first inserted into the through hole, and then the molten adhesive may be injected into the gap between the coupling pin and the inner surface of the through hole, and then the adhesive may be solidified.

(Embodiment 2)
In the first embodiment, the bonding pin is bonded to the inner surface of the through hole and the inner surface of the concave portion using an adhesive. In the second embodiment, the bonding pin is bonded to the inner surface of the through hole and the inner surface of the concave portion using solder. Yes. Since the other configuration of the battery pack according to the present embodiment is substantially the same as the configuration of the battery pack according to the first embodiment, the following mainly describes a bonding pin fixing method.

  FIG. 6 is a cross-sectional view showing a fixed state between the battery 1 and the end case 6 in the present embodiment.

  Similarly to the first embodiment, each end portion 3 of the battery 1 is formed with each recess 3a, and each coupling pin 12 has each through-hole in the end case 6 so that each tip 12b exists in each recess 3a. 11 is penetrated. In the present embodiment, each coupling pin 12 is fixed to the inner surface of each through hole 11 and the inner surface of each recess 3 a via solder 41.

  FIG. 7 is a cross-sectional view showing one step of the manufacturing process of the battery pack according to the present embodiment.

  First, according to the method described in the first embodiment, the steps shown in FIG.

  Next, as shown in FIG. 7, each coupling pin 12, the inner surface of each recess 3a, and the inner surface of each through hole 11 are welded together using resistance welding. Specifically, first, one welding electrode of the pair of welding electrodes is brought into contact with and pressed against the head portion 12a of each coupling pin 12, and the other welding electrode (not shown) is pushed to the tip of each fixing pin 12. Press against 12b. At this time, it is preferable that the other welding electrode is brought into contact with the periphery of the tip 12b of the coupling pin 12 through a work opening (not shown) formed in the battery or the end case. Next, a current is passed between the pair of welding electrodes. As a result, the coupling pins 12, the inner surfaces of the recesses 3 a, and the inner surfaces of the through holes 11 are melted, so that the coupling pins 12 are welded to the inner surfaces of the recesses 3 a and the inner surfaces of the through holes 11. Thus, since each coupling pin 12 is adhered to the inner surface of each recess 3a via solder, a dimensional error between each coupling pin 12 and each recess 3a can be absorbed by the solder. In other words, solder serves as a buffer to alleviate dimensional errors. Since each coupling pin 12, the inner surface of each recess 3a, and the inner surface of each through hole 6 are welded to each other in this way, each coupling pin 12, each recess 3a, and each through hole 6 have the shapes shown in FIG. May be slightly distorted.

  Thereafter, the exterior label 27 is attached according to the method described in the first embodiment. Thereby, the battery pack concerning this embodiment can be manufactured.

  As described above, in this embodiment, each coupling pin 12 is bonded to the inner surface of each through-hole 11 and the inner surface of each recess 3a using the solder 41. However, as in the first embodiment, the recesses 3a and 3a are respectively formed on the one end surface 3 of the battery 1, and the coupling pins 12 and 12 are connected so that the tips 12b and 12b are present in the recesses 3a and 3a. Since the pins 12 and 12 are penetrated by the through holes 11 and 11, the same effect as the first embodiment is obtained.

  In addition, the position which arrange | positions a pair of welding electrode is not limited to the position of the said description. For example, both of the pair of welding electrodes may be placed on the head 12 a of each connecting pin 12.

(Embodiment 3 of the invention)
In the second embodiment, the coupling pin is welded to the inner surface of the through hole and the inner surface of the recess using resistance welding, but in the third embodiment, the coupling pin is welded to the inner surface of the through hole and the inner surface of the recess using the ultrasonic welding method. Is welded. Since the other configuration of the battery pack according to the present embodiment is substantially the same as the configuration of the battery pack according to the second embodiment, the welding method will be mainly described below.

  FIG. 8 is a cross-sectional view showing one step of the manufacturing process of the battery pack according to the present embodiment.

  First, according to the method described in the first embodiment, the steps shown in FIG.

  Next, each coupling pin 12 and the inner surface of each recess 3a and the inner surface of each through hole 11 are welded to each other using an ultrasonic welding method. Specifically, as shown in FIG. 8, an ultrasonic vibration 53 is applied to each coupling pin 12 and pressure is applied simultaneously. As a result, frictional heat is generated between each coupling pin 12 and the inner surface of each recess 3a and the inner surface of each through hole 11, and the friction heat causes each coupling pin 12, the inner surface of each recess 3a, and the inner surface of each through hole 11. As a result, the connecting pins 12 are welded to the inner surfaces of the recesses 3 a and the inner surfaces of the through holes 11. In addition, it is preferable to adhere each coupling pin 12 to each recess 3a using solder as in the second embodiment, because the dimensional error between each coupling pin 12 and each recess 3a can be absorbed by the solder.

  Thereafter, the exterior label is attached according to the method described in the first embodiment. Thereby, the battery pack concerning this embodiment can be manufactured.

  As described above, in this embodiment, each coupling pin 12 is bonded to the inner surface of each through-hole 11 and the inner surface of each recess 3a using an ultrasonic welding method. However, as in the first embodiment, the recesses 3a and 3a are respectively formed on the one end surface 3 of the battery 1, and the coupling pins 12 and 12 are connected so that the tips 12b and 12b are present in the recesses 3a and 3a. Since the pins 12 and 12 are penetrated by the through holes 11 and 11, the same effect as the first embodiment is obtained.

(Other embodiments)
This invention is good also as following structures about the said Embodiment 1-3.

  The number of recesses, through-holes, and connecting pins are all two, but the number is not particularly limited. However, in order to firmly fix the end case to the one end surface of the battery, it is preferable that two or more recesses and through holes are formed.

  Although the hole diameter of the through hole and the opening diameter of the recess are substantially the same as shown in FIGS. 3 and 6, there is no particular limitation. The hole diameter of the through hole may be smaller or larger than the opening diameter of the recess. What is necessary is just to be able to provide a coupling pin in a through-hole so that the front-end | tip of a coupling pin exists in a recessed part.

  Although the example in which the end case is fixed to one end surface of the battery using the coupling pin is shown, the end case may be fixed to the circuit board using the coupling pin. Even in this case, it is preferable that the recess is formed in the circuit board and the coupling pin is inserted into the through hole so that the tip is in the recess. As a result, the end case and the circuit board can be electrically connected using the coupling pins. Therefore, when the end case is fixed to the circuit board, the first connection bracket 13 and the connection plate 14 shown in FIG. Can be omitted.

  Needless to say, the configuration of the battery electrode group and the electrolyte solution is not limited to the above description.

  The present invention may be configured as follows for the second and third embodiments.

  The method for welding the connecting pins is not particularly limited. The coupling pin may be welded to the inner surface of the recess and the inner surface of the through hole by using a welding method other than the resistance welding method and the ultrasonic welding method.

  If the materials and welding conditions of the coupling pin, the battery case and the end case are different, only the coupling pin may melt, or only the inner surface of the recess and the inner surface of the through hole may melt. The member to be melted is not particularly limited as long as the connecting pin, the inner surface of the recess, and the inner surface of the through hole are welded to each other.

  In the present invention, since the end case is fixed to the battery by bonding the connecting pin to the inner wall surface of the through hole of the end case and the inner wall surface of the concave portion of the battery via an adhesive or the like, screws are used. Thus, the size of the coupling pin can be reduced as compared with the case where the end case is fixed to the battery. Therefore, it is useful for small battery packs for portable electronic devices.

1 is an external perspective view of a battery pack according to Embodiment 1 of the present invention. 1 is an exploded perspective view of a battery pack according to Embodiment 1 of the present invention. Sectional drawing which shows a mode that the edge part case in Embodiment 1 of this invention is adhering to the one end surface of a battery. (A) And (b) is sectional drawing which shows a mode that an edge part case is adhering to the one end surface, respectively, when the one end surface of a battery is flat. (A) And (b) is sectional drawing which shows the one part process of the manufacturing process of the battery pack concerning Embodiment 1 of this invention, respectively. Sectional drawing which shows a mode that the edge part case in Embodiment 2 of this invention is adhering to the one end surface of a battery. Sectional drawing which shows a part of process of the manufacturing process of the battery pack concerning Embodiment 2 of this invention. Sectional drawing which shows a part of process of the manufacturing process of the battery pack concerning Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Battery 3,73 One end surface 3a Recessed part 5 Circuit board 6 End part case 10 Battery pack 11 Through-hole 12 Bonding pin 12b Tip 31 Adhesive 41 Solder

Claims (8)

A battery having a recess formed on one end surface;
An end case that covers the one end surface of the battery and has a through hole that communicates with the opening of the recess;
A battery pack comprising a through-hole penetrating through the through-hole so that a tip exists in the concave portion, and an inner surface of the through-hole and a coupling pin fixed to the inner surface of the concave portion.   The battery pack according to claim 1, wherein the coupling pin is bonded to the inner surface of the through hole and the inner surface of the recess through an adhesive.   The battery pack according to claim 1, wherein the coupling pin is fixed to an inner surface of the through hole and an inner surface of the recess through solder. A step of preparing a battery in which a recess is formed on one end surface and an end case in which a through hole is formed;
Covering the end case with the one end surface of the battery so that the through hole communicates with the opening of the recess;
Inserting a coupling pin into the through hole until a pin tip passes through the through hole and is present in the recess;
A battery pack manufacturing method comprising: a fixing step of fixing the coupling pin to the inner surface of the recess and the inner surface of the through hole.   5. The method of manufacturing a battery pack according to claim 4, wherein, in the fixing step, the coupling pin, the inner surface of the concave portion, and the inner surface of the through hole are bonded to each other using an adhesive.   5. The method of manufacturing a battery pack according to claim 4, wherein, in the fixing step, the coupling pin, the inner surface of the recess, and the inner surface of the through hole are welded to each other.   The battery pack manufacturing method according to claim 6, wherein, in the fixing step, the coupling pin, the inner surface of the concave portion, and the inner surface of the through hole are welded to each other using a resistance welding method.   The method for manufacturing a battery pack according to claim 6, wherein in the fixing step, the coupling pin, the inner surface of the concave portion, and the inner surface of the through hole are welded to each other using an ultrasonic welding method.

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