JP6453071B2 - Battery pack - Google Patents

Description

  The present invention relates to a battery pack in which a battery that can be charged and discharged is stored in an outer case, and more particularly, to a battery pack in which the outer case is connected by ultrasonic welding and the battery is stored in a closed interior.

  The plastic outer case vibrates the connecting surfaces facing each other with ultrasonic waves, and heats and welds the plastics of the connecting surfaces with the energy of ultrasonic vibrations, ensuring a short time without using any adhesive. Can be linked. For this reason, many battery packs are assembled by molding the outer case with plastic and ultrasonically welding the opposing connection surfaces of the peripheral walls provided along the outer peripheral edge. In the battery pack having this structure, a pair of cases, that is, a first case and a second case are molded of thermoplastic resin, and the opposing connection surfaces of the peripheral walls provided along the outer periphery of the first case and the second case are provided. It arrange | positions in the state made to contact, the ultrasonic horn is pressed, and it ultrasonically vibrates and welds in the state which presses the opposing connection surface of a surrounding wall.

  In order to ultrasonically weld the opposing connection surface of the peripheral wall of the plastic outer case without displacement, a battery pack having an engaging claw and a slit provided on the opposing connection surface to be ultrasonically welded has been developed. (See Patent Document 1)

  In this battery pack, a plurality of engaging claws are provided on the opposing connecting surface of the peripheral wall of one case so as to protrude, and a slit for guiding the engaging claws is provided on the opposing connecting surface of the other case. The opposing connection surface is ultrasonically welded with the nail inserted into the slit. The engaging claw and the slit are provided so as to extend in the longitudinal direction of the opposing connection surface, and prevent positional displacement in the thickness direction of the opposing connection surface, that is, the lateral direction. Therefore, the battery pack having this structure can be ultrasonically welded without causing the circumferential wall to be displaced in the lateral direction by ultrasonically vibrating the opposing connecting surface in a state where the engaging claws are inserted into the slits. This is because it is possible to ultrasonically vibrate in a state where the opposing coupling surfaces are prevented from being displaced in the lateral direction by the engaging claws and slits and the opposing coupling surfaces are in close contact with each other. The opposing connection surfaces that are ultrasonically vibrated in close contact with each other are efficiently heated and melted by the energy of ultrasonic vibration and can be reliably heat-welded.

  Furthermore, a case having a structure in which a pair of cases are more firmly connected by a connection structure that combines ultrasonic welding and a fitting structure has been developed. (See Patent Document 2)

  In this case, a pair of ribs are provided inside the peripheral wall so as to be orthogonal to each other. The pair of orthogonal ribs are connected to each other by a fitting structure, and the case is more firmly connected by ultrasonic welding of the pair of ribs that are connected by the fitting structure.

JP 2006-253153 A JP 2004-327342 A

  The exterior case of Patent Document 1 has an advantage that ultrasonic welding can be performed accurately by performing ultrasonic welding in a state where the engaging claws provided on the welding surface are guided to the slits, and preventing the lateral displacement of the peripheral wall. In addition, the case of Patent Document 2 has an advantage that the two cases can be more reliably connected by ultrasonic welding while using a pair of ribs provided so as to be orthogonal to each other as a fitting structure. However, since these cases are ultrasonically welded by providing engaging claws and ribs at the ultrasonic welded part, the two parts cannot be reliably removed by forming the part to be joined by ultrasonic welding thinly. There is a disadvantage that can not be connected.

  The present invention has been developed for the purpose of solving the above drawbacks. An important object of the present invention is to provide a battery pack that can be ultrasonically welded and connected so that the first case and the second case are not reliably detached while forming a portion to be ultrasonically welded thin.

In the battery pack of the present invention, a battery that can be charged and discharged is housed in the outer case 2. The exterior case 2 is composed of a plastic first case 2A and a second case 2B, which are connected to the opposing connection surfaces 12 provided along the outer periphery and are provided with a battery storage space 10 inside. The opposing connection surfaces 12 of the first case 2A and the second case 2B are connected to the first case 2A via a locking hook 31 in the welding region 4 formed by ultrasonic welding and the non-welding region 5 in which ultrasonic welding is not performed. Are connected to each other by a locking connecting portion 3 that is connected to the second case 2B. The locking hook 31 has a locking portion 31a provided on the first case 2A, extending to the inner surface of the second case 2B and locked to the inner surface of the second case 2B. A lock receiving portion 32 for guiding the lock portion 31a of the lock hook 31 is provided on the inner surface. In the locking connection portion 3, the locking hook 31 of the first case 2A is hooked on the locking receiving portion 32 of the second case 2B, thereby connecting the first case 2A and the second case 2B. The opposing connection surface 12 arranged on the side surface of the battery 1 is used as the welding region 4, the intermediate part of the opposing connection surface 12 arranged on the electrode surface side of the battery 1 is used as the welding region 4, and the end is used as the locking connection unit 3. Yes.

  In the battery pack of the present invention, the outer case 2 can be provided with the locking connection portion 3 at the corner of the opposing connection surface 12.

  In the battery pack of the present invention, the battery 1 is a cylindrical battery 1A or a rectangular battery having a curved portion on the side surface, and the first case 2A and the second case 2B are arranged on both sides of the flat portion 15 along the outside of the battery 1. Formed by a surface plate portion 13 formed into a shape for connecting curved portions 16 formed by bending, and end surface walls 14 provided at both ends of the surface plate portion 13, the opposing connection surfaces of the end surface walls 14 The locking connection part 3 can be provided in the edge part of 12, and the welding area | region 4 can be provided in an intermediate part.

  In the battery pack of the present invention, the circuit board 6 is accommodated inside the end face wall 14 of the outer case 2 so as to be in contact with the end face wall 14, and between the end portion of the circuit board 6 and the inner surface of the outer case 2. An insertion space 30 for the stop hook 31 can be provided, and the engagement hook 31 can be disposed in the insertion space 30 so as to be disposed in the same plane as the circuit board 6.

  The battery pack of the present invention includes a battery holder 7 that places the battery 1 stored in the outer case 2 at a fixed position in the storage space 10, and the battery holder 7 is connected to the locking hook 31 at the locking connection portion 3. A retaining pressing portion 33 that is located on the back surface and prevents the locking portion 31 a from coming off the locking receiving portion 32 can be provided.

  Furthermore, in the battery pack of the present invention, the retaining pressing portion 33 is a protruding piece that protrudes from the end surface of the battery holder 7 toward the inner surface of the second case 2B. It can be guided between the inner surface of the second case 2 </ b> B and the retaining pressing portion 33 to the locking receiving portion 32.

  The battery pack of the present invention is characterized in that the first case and the second case that are separately molded are ultrasonically welded and connected so as not to be surely removed while the ultrasonic welding part of the outer case is thinly formed. There is. This is because the opposing connection surface provided on the outer peripheral edge of the case is securely connected by ultrasonic welding in the welding region, and the non-welding region that is not ultrasonically welded is used as the locking connection portion. This is because the locking hook provided in one case is hooked and connected to the fitting recess of the second case. In the battery pack of the present invention, the opposing connection surfaces provided on the outer peripheral edge of the outer case are connected by ultrasonic welding without providing a locking hook in the welding region, and with the locking hook in the non-welding region. Since the first case and the second case are connected, the outer peripheral edge of the outer case is reliably and stably connected, while the opposing connection surface is narrow in the welding region, that is, the peripheral wall can be thinned. . In the non-welding area, the first case and the second case are connected via the locking hook, so that the outer peripheral edge of the exterior case can be connected so as not to come off by impact or the like even in the non-welding area. .

It is a perspective view of the battery pack concerning one Example of this invention. It is a disassembled perspective view of the battery pack shown in FIG. It is the disassembled perspective view which looked at the battery pack shown in FIG. 2 from the back side. It is a disassembled perspective view of the battery block of the battery pack shown in FIG. It is a top view of the battery pack shown in FIG. It is the top view which removed the upper case of the battery pack shown in FIG. It is the partially expanded bottom perspective view which removed the lower case of the battery pack shown in FIG. It is the front view which shows the process of ultrasonically welding an exterior case, and a partial expanded sectional view. FIG. 6 is a partially enlarged IX-IX cross-sectional view of the battery pack shown in FIG. 5. FIG. 6 is a partial enlarged XX sectional view of the battery pack shown in FIG. 5.

  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, this specification does not limit the members shown in the claims to the members of the embodiments.

  The battery pack shown in FIGS. 1 to 10 houses a battery 1 that can be charged and discharged inside an exterior case 2. In the battery pack of the present invention, two cylindrical batteries 1A are arranged in two rows in parallel and stored in the outer case 2. The battery pack can adjust the charge / discharge capacity by the number of the batteries 1 housed in the outer case 2. Therefore, the battery pack accommodates the number of batteries 1 having a charge / discharge capacity optimum for the intended use. The cylindrical battery 1A is a lithium ion secondary battery. Lithium ion secondary batteries have a large charge / discharge capacity with respect to capacity and weight, can reduce the outer shape of the battery pack, and can be lightened to increase the charge / discharge capacity. However, the battery pack of the present invention can use all other chargeable / dischargeable batteries in place of the lithium ion secondary battery. Furthermore, in the battery pack shown in the figure, the battery 1 is a cylindrical battery 1A, but the battery 1 may be a square battery, a laminated battery, or the like.

  The outer case 2 is composed of a first case 2A and a second case 2B in which thermoplastic resin plastics are separately molded. In the first case 2A and the second case 2B, the outer shape of the connecting portion is the same, the outer peripheral wall 11 is connected by the opposing connecting surface 12, and the storage space 10 for the battery 1 is provided inside. In the illustrated battery pack, the upper case is a first case 2A and the lower case is a second case 2B.

  The first case 2 </ b> A and the second case 2 </ b> B include a surface plate portion 13 provided with curved portions 16 that are curved along the outside of the cylindrical battery 1 </ b> A on both sides of the flat portion 15, and both end portions of the surface plate portion 13. The provided end face wall 14 is integrally formed of plastic. 1-3, the end surface wall 14 of the second case 2B is higher than the end surface wall 14 of the first case 2A, and the second case 2B is deeper than the first case 2A. In the exterior case 2, the curved portions 16 on both sides of the first case 2 </ b> A and the second case 2 </ b> B and the end surface walls 14 at both ends form a peripheral wall 11, and the opposing connection surfaces 12 of the peripheral wall 11 are connected to each other. .

  As shown in FIGS. 2, 3, and 8, the first case 2 </ b> A is provided with a horizontal portion 17 that presses the ultrasonic horn 50 along both side edges of the curved portion 16 on both sides of the surface plate portion 13. The horizontal portion 17 is provided with welding ribs 18 extending vertically downward along the outer edge. Furthermore, as shown in FIG. 10, the first case 2 </ b> A is provided with welding ribs 18 at the lower end portion of the end face wall 14 and at the lower end portion facing the flat portion 15 of the surface plate portion 13. The welding rib 18 has a lower end surface as the opposing connection surface 12. The opposing connection surface 12 of the welding rib 18 is ultrasonically welded and fixed to the opposing connection surface 12 provided on the upper edge of the peripheral wall 11 of the second case 2B.

  The welding rib 18 of the first case 2 </ b> A is provided with a ridge 21 on one side of the opposing connection surface 12. This ridge 21 is inserted into the fitting recess 22 provided in the opposing connection surface 12 of the peripheral wall 11 of the second case 2B, and is ultrasonically welded. The exterior case 2 shown in the partially enlarged cross-sectional views of FIGS. 8 and 10 is provided with a ridge 21 along the inner side of the welding rib 18, and the ridge 21 along the inner side of the peripheral wall 11 of the second case 2 </ b> B. A fitting recess 22 for guiding with the fitting structure is provided. The ridges 21 and the fitting recesses 22 are arranged on one side of the opposing connection surface 12 of the welding rib 18 and the peripheral wall 11 and are provided so as to extend in the longitudinal direction. The opposing connection surface 12 that guides the ridges 21 to the fitting recesses 22 is welded by the energy of ultrasonic vibration. The welded rib 18 and the opposed connecting surface 12 of the peripheral wall 11 are ultrasonically vibrated while being pressed against each other, and are heated and melted by the energy of ultrasonic vibration to be welded. In order to effectively heat and melt the opposed connecting surface 12 by ultrasonic vibration, the opposed surfaces of the welding rib 18 and the peripheral wall 11 are located on a horizontal plane orthogonal to the direction of ultrasonic vibration. That is, the front end surface of the ridge 21, the front end surface of the peripheral wall 11, and the surfaces pressed by these surfaces are in a horizontal plane and are disposed in a plane orthogonal to the vertical direction in which the ultrasonic vibration occurs. Is done.

  The second case 2B is deeper than the first case 2A. As shown in FIG. 8, the upper portions of the curved portions 16 on both sides of the surface plate portion 13 are the vertical walls 19 and the upper end surfaces of the vertical walls 19 are the opposing connection surfaces 12. The opposing connecting surface 12 is ultrasonically welded and fixed to the lower end surface of the welding rib 18 of the first case 2A.

  In the outer case 2 of FIG. 8, the protrusions 21 of the welding ribs 18 are disposed inside the opposing connection surface 12, so that the horizontal portion 17 of the first case 2 </ b> A is pressed by the ultrasonic horn 50 and ultrasonically vibrated. Thus, the welding rib 18 can be prevented from spreading outward. This is because the projection 21 is connected to the fitting recess 22 in a fitting structure, and the welding rib 18 is ultrasonically vibrated.

  The outer case 2 is not fixed by ultrasonic welding of the entire opposing connection surface 12 provided on the outer periphery of the first case 2A and the second case 2B. The opposing connection surface 12 has a welding region 4 that is connected by ultrasonic welding and a non-welding region 5 that is not ultrasonically welded. The non-welding region 5 connects the first case 2 </ b> A via a locking hook 31. It is connected by a locking connection portion 3 connected to the second case 2B. The locking hook 31 is formed integrally with the first case 2A, extends to the inner surface of the second case 2B, and is hook-shaped engaged with the locking receiving portion 32 of the second case 2B. A stop 31a is provided at the tip. The second case 2 </ b> B is provided with an engagement receiving portion 32 that guides the engagement portion 31 a of the engagement hook 31 on the inner surface of the peripheral wall 11. The outer case 2 connects the first case 2A and the second case 2B by hooking the locking hook 31 of the first case 2A to the locking receiving portion 32 of the second case 2B in the locking connection portion 3. Yes.

  The exterior case 2 shown in FIGS. 2 and 3 is provided with a locking connection portion 3 at the corner of the opposing connection surface 12. The exterior case 2 has a locking connection portion 3 at the corner of the opposing connection surface 12 located on the electrode surface side of the battery 1 incorporated therein. Furthermore, as shown in FIG. 6, the exterior case 2 in these drawings is provided with a locking connection portion 3 at an end portion of the opposing connection surface 12 of the end wall 14 and a welding region 4 at an intermediate portion. The end face walls 14 of the first case 2A and the second case 2B have a shape in which the middle part of the upper edge is a flat shape and both sides are curved.

  As shown in FIG. 8, the ultrasonic horn 50 has a pressing surface 51 that is pressed against the plastic to be welded, as a surface orthogonal to the direction of ultrasonic vibration. This is because when the pressing surface 51 is inclined with respect to the ultrasonic vibration direction, the ultrasonic vibration is efficiently transmitted and heat cannot be generated. The end face wall 14 of the outer case 2 has an intermediate portion at the upper edge as a horizontal plane (a plane portion 15 of the surface plate portion 13), so that the pressing surface 51 of the ultrasonic horn 50 is pressed against this portion to effectively ultrasonically vibrate. it can. However, since both sides of the end face wall 14 are curved (the curved portion 16 of the surface plate portion 13), the ultrasonic horn 50 cannot efficiently ultrasonically vibrate. The end wall 14 has an intermediate portion of the opposing connection surface 12 that can be efficiently welded by ultrasonic vibration as a welding region 4, but the end portion of the opposing connection surface 12 that cannot be reliably ultrasonically welded serves as a locking connection portion 3. The first case 2A and the second case 2B are connected via the stop hook 31.

  The exterior case 2 of FIGS. 2 and 3 is provided with a locking connection portion 3 at one corner of one end face wall 14. The outer case 2 can be connected so that the corners provided with the locking connecting portions 3 are not detached by the locking hooks 31. The locking connecting portion 3 is thicker than the welding region 4 because the locking hook 31 is provided inside. The exterior case 2 in which the locking connection part 3 is provided only at one corner of the opposing connection surface 12 does not need to thicken only one corner and thicken the other corners. Can be increased. The exterior case 2 can firmly connect the first case 2A and the second case 2B by providing the locking connection portions 3 at two or more corners of the opposing connection surface 12. In particular, the locking connection portions 3 are provided at the four corners of the opposing connection surface 12, so that the first case 2A and the second case 2B can be connected most strongly.

  FIG. 7 shows a state in which the locking hook 31 protrudes downward from the end face wall 14 of the first case 2A, and FIG. 9 shows a state in which the locking hook 31 is guided by the locking receiving portion 32. The locking hook 31 shown in these drawings is connected to the inner surface of the end surface wall 14 of the first case 2A, protrudes further downward from the end surface wall 14, and is hooked to the locking receiving portion 32 at the distal end portion. A shaped locking portion 31a is provided. The locking portion 31a is provided so that the hook protrudes outward. The locking hook 31 is integrally formed on the first case 2A made of plastic.

  The second case 2B is provided with a latch receiving portion 32 on the inner surface of the end face wall 14 at a position where the latch portion 31a of the latch hook 31 is guided. The locking receiving portion 32 is provided at a position for guiding the locking portion 31a of the locking hook 31 in a state where the first case 2A is connected to the second case 2B. The locking receiving portion 32 shown in the figure is a locking recess provided on the inner surface of the end wall 14. The latch receiving portion 32, which is a latching recess, has a feature that the latching portion 31a can be reliably guided by being guided into the recess while increasing the protruding amount of the hook-shaped latching portion 31a. However, the latch receiving part 32 does not necessarily need to be a recess. The latch receiving portion 32 can have any other structure capable of guiding and latching the latching portion 31a of the latching hook 31 in a state where the first case 2A is coupled to the second case 2B.

  The outer case 2 can temporarily fix the first case 2A and the second case 2B in place by guiding the locking hook 31 to the locking receiving portion 32. Therefore, when the outer case 2 is ultrasonically welded, the locking hook 31 is guided to the locking receiving portion 32 to connect the first case 2A and the second case 2B to a fixed position. The welding zone 4 can be ultrasonically welded by pressing the sonic horn 50. Therefore, the first case 2A and the second case 2B can be connected by ultrasonic welding so as not to be displaced.

  One end face wall 14 of the second case 2B is provided with an electrode window 23 through which the positive and negative electrode terminals 41 and the signal terminal 42 are exposed. The exterior case 2 is provided with a locking connection portion 3 in the vicinity of the electrode window 23 at the end of the end face wall 14 where the electrode window 23 is opened. The outer case 2 is easily reduced in strength by providing the electrode window 23. However, the outer case 2 is provided with a locking connection portion 3 in the vicinity of the electrode window 23 to connect the first case 2A and the second case 2B. Therefore, there is a feature that the strength of connection can be ensured by covering the strength reduction caused by opening the electrode window 23.

  A circuit board 6 is disposed inside the electrode window 23. As shown in FIGS. 4 and 7, the circuit board 6 is provided with an electrode terminal 41 and a signal terminal 42 at the position of the electrode window 23. The circuit board 6 is connected to a battery holder 7 that places the battery 1 in a fixed position.

  The battery holder 7 is molded of plastic so that the two cylindrical batteries 1A can be placed in place while being insulated. The battery holder 7 shown in the figure includes an insulating plate portion 7A disposed between two cylindrical batteries 1A and an end surface plate portion 7B disposed on the end surface side of the cylindrical battery 1A. The battery holder 7 has end plate portions 7B connected to both ends of the insulating plate portion 7A, and the cylindrical battery 1A is disposed between the facing end plate portions 7B. The insulating plate portion 7A has curved surfaces on both sides, which are opposed to the cylindrical battery 1A, so that the two cylindrical batteries 1A can be placed at fixed positions. The battery holder 7 holds the two cylindrical batteries 1A in a fixed position in a posture parallel to each other and in opposite directions.

  The battery holder 7 is assembled to the battery block 9 by arranging the circuit board 6 and the battery 1 at fixed positions. In the battery block 9 shown in the exploded perspective view of FIG. 4, two cylindrical batteries 1 </ b> A are connected in series with a lead plate 45 and connected to the circuit board 6, and arranged at a fixed position of the battery holder 7. Furthermore, the end face electrode of the cylindrical battery 1 </ b> A exposed from the opening of the end face plate portion 7 </ b> B disposed on the circuit board 6 side is connected to the circuit board 6 through the lead plate 46.

  The battery block 9 shown in FIGS. 2, 6, and 7 is formed by linearly cutting the end of the circuit board 6 (the right side in FIGS. 2 and 7, the lower side in FIG. 6) and the inner surface of the peripheral wall 11. An insertion space 30 for the locking hook 31 is provided between them. 7 shows a state in which the locking hook 31 is disposed in the insertion space 30 provided on the side of the circuit board 6. In this battery pack, the circuit board 6 is cut away and the insertion space 30 for the locking hook 31 is provided. Therefore, it is not necessary to provide a dedicated space for inserting the locking hook 31.

  Further, the battery holder 7 shown in FIG. 7 and FIG. 9 is provided on the end face plate portion 7B on the side facing the locking connecting portion 3 on the back side of the locking hook 31 and the locking portion 31a is the locking receiving portion. A retaining pressing portion 33 is provided for preventing the slipping from the 32. The retaining pressing portion 33 shown in the drawing is integrally formed with the battery holder 7 as a protruding piece that protrudes from the end surface plate portion 7 </ b> B toward the peripheral wall 11. The retaining pressing portion 33 that is a protruding piece is formed such that the tip thereof abuts against the back surface of the locking portion 31a of the locking hook 31 in a state where the battery block 9 is disposed at a fixed position of the second case 2B. . The retaining pressing portion 33 supports the locking hook 31 from the back side when an impact load is applied to the battery pack, and prevents the locking hook 31 from coming off the locking receiving portion 32.

  As shown in FIG. 7, the retaining pressing portion 33, which is a protruding piece, is formed so that the thickness in the vertical direction is smaller than the horizontal width in the horizontal direction, that is, thin, and can be elastically deformed in the vertical direction in the figure. As shown by an arrow A in FIG. 9, the pull-out pressing portion 33 is pressed by the tip end portion of the locking hook 31 in a state where the locking portion 31 a of the locking hook 31 is pushed into the insertion space 30 and inserted. It is elastically deformed. That is, the retaining pressing portion 33 is an elastically deformable projecting piece, and the projecting piece is elastically deformed to pass the retaining portion 31a of the retaining hook 31 between the second case 2B and the retaining pressing portion 33. Thus, it can be smoothly guided to the locking receiving portion 32. When the locking portion 31a is guided to the locking receiving portion 32, the retaining pressing portion 33 returns to its original shape as shown in FIG. 9, and supports the locking hook 31 from the back surface. Further, when the locking portion 31a guided by the locking receiving portion 32 tries to move in a direction to come out of the locking receiving portion 32, the back surface of the locking hook 31 is pressed by the retaining pressing portion 33 and the locking portion 31a is moved. Movement is prevented. Therefore, the retaining pressing portion 33 of this structure prevents the locking portion 31a from coming off the locking receiving portion 32 due to an impact or the like while smoothly guiding the locking portion 31a of the locking hook 31 to the locking receiving portion 32. It can be effectively prevented.

  However, the retaining pressing portion does not necessarily have a structure that can be elastically deformed, and may be a convex portion, a ridge, a rib, or the like that supports the locking hook from the back side without elastic deformation. It can be structured to guide the locking hook or the locking portion to the locking receiving portion while elastically deforming the locking hook or the locking portion, or when the locking hook is pushed into the insertion space, the peripheral wall of the second case is expanded outward. This is because the engaging part can be inserted between the peripheral wall and the retaining pressing part and inserted into the engaging receiving part while being elastically deformed in the opened state.

  The battery block 9 is disposed inside the outer case 2 and exposes the electrode terminal 41 and the signal terminal 42 fixed to the circuit board 6 from the electrode window 23 to the outside. The circuit board 6 is mounted with a protection circuit (not shown) that protects the battery 1 by controlling the charge / discharge current of the battery 1. The protection circuit controls the charge / discharge current so that the voltage, remaining capacity, and temperature of the battery 1 are in a preset range. The battery block 9 is disposed in the storage space 10 of the outer case 2 with a fitting structure, and is stored in a fixed position.

The battery pack of the present invention is assembled in the following steps.
(1) The battery block 9 is accommodated in the second case 2B, and the battery block 9 is arranged at a fixed position of the second case 2B. The battery block 9 is arranged at a fixed position in the second case 2B with a fitting structure. In this state, the electrode terminal 41 and the signal terminal 42 are disposed inside the electrode window 23 of the second case 2B.
(2) The first case 2A is placed on the second case 2B, the locking hook 31 is guided to the locking receiving portion 32, and the second case 2B and the first case 2A are connected via the locking connecting portion 3. Connect to a fixed position.
(3) As shown in FIG. 8, the connected 2nd case 2B and 1st case 2A are mounted on the base 55 which ultrasonically welds. The pressing surface 51 of the ultrasonic horn 50 is brought into contact with the upper surface of the first case 2A, and the first case 2A and the second case 2B are ultrasonically welded in the welding region 4.

  As described above, the region in which the ultrasonic horn 50 presses the first case 2A and ultrasonically vibrates in the step of ultrasonically welding the outer case 2 is indicated by the cross-hatching of the chain line in FIG. The pressing surface 51 provided on the lower surface side of the ultrasonic horn 50 is provided on the flat portion 15 of the surface plate portion 13 provided on the intermediate portion of the end surface wall 14 of the first case 2A and on both sides of the surface plate portion 13. It is in close contact with the horizontal portion 17 and is ultrasonically vibrated in a state of being pressed with a predetermined pressure. On the lower surface side of the ultrasonic horn 50 in the figure, a portion for pressing the flat surface portion 15 of the surface plate portion 13 located in the middle portion of the end surface wall 14 of the first case 2 </ b> A is provided on both sides of the surface plate portion 13. Since the part which presses the horizontal part 17 is provided, both sides of the 1st case 2A and the intermediate part of the end surface wall 14 are ultrasonically welded together. FIG. 6 shows the opposing connection surface 12 of the second case 2B from which the first case 2A is removed, and the ultrasonic welded region, that is, the welded region 4 is shown by cross-hatching of chain lines. 1 has a groove-like recess 24 extending in the longitudinal direction from one end face wall 14 at the center of the surface plate portion 13 of the first case 2A. The connecting surface 12 has a central portion that is not subjected to ultrasonic welding.

  In the present embodiment, the locking connection portion 3 is provided at the corner of the opposing connection surface 12. However, if there is a space for providing the locking connection portion 3 in the non-welded region 5 where ultrasonic welding is not performed. Alternatively, it may be provided at the central portion of the opposed connecting surface 12. For example, the exterior case 2 of FIG. 6 has the non-welding area | region 5 where the opposing connection surface 12 is not ultrasonically welded in the center part of the end surface wall 14 by providing the groove-shaped recessed part 24 in 1st case 2A. However, the locking connection portion 3 may be provided in the non-welded region 5. Thereby, the connection intensity | strength of the center part of the opposing connection surface 12 can be raised. That is, the locking connection portion 3 can increase the connection strength of the non-welded region 5 where the opposing connection surface 12 is not ultrasonically welded.

  In the present embodiment, the locking receiving portion 32 of the second case 2B to which the locking hook 31 of the first case 2A is hooked is used as the locking recess in the locking connecting portion 3, but the locking of the second case 2B The latch receiving portion 32 may be a latch convex portion protruding from the inner surface of the second case or a latch stepped portion where the thickness of the second case is reduced. In other words, the latch receiving portion may be structured such that the latch connection portion can be latched by catching the latch portion of the latch hook. Here, as the locking convex portion protruding from the inner surface of the second case, for example, an inclined surface that gradually protrudes downward is provided on the inner surface of the upper portion on the first case side, and the bottom surface side of the second case The lower end surface can be a convex portion having a vertical surface. The locking projection of this shape can be made difficult to come off by hooking the locking portion on the vertical surface while smoothly guiding the locking portion of the locking hook along the inclined surface. Moreover, the structure which makes a latching receiving part a latching convex part locks a latching part on a latching convex part, elastically deforming the latching hook extended below from the end surface wall of a 1st case inside. The elastically deformed locking hook is urged in the direction in which the locking portion is locked to the locking convex portion by the elastic force to be restored, so that it can be more difficult to come off.

  In the present embodiment, the battery 1 is a cylindrical battery 1A. However, the battery is a prismatic battery having a curved portion on the side surface, for example, a prismatic battery having a semicircular side surface, or a rectangular shape having a large R on the side surface. A battery may be used. The prismatic battery can be a prismatic battery in which a curved portion is formed on a side surface by providing R at a corner portion of a rectangular tube-shaped outer can. When the battery is a square battery, the locking connection portion 3 can be provided at the corner of the opposing connection surface 12 located on the electrode surface side of the square battery.

  The present invention can be conveniently used as a battery pack in which two cases are ultrasonically welded to provide a storage space closed inside, and a battery is stored in this storage space.

DESCRIPTION OF SYMBOLS 1 ... Battery 1A ... Cylindrical battery 2 ... Exterior case 2A ... 1st case 2B ... 2nd case 3 ... Locking connection part 4 ... Welding area | region 5 ... Non-welding area | region 6 ... Circuit board 7 ... Battery holder 7A ... Insulating plate part 7B ... End face plate part 9 ... Battery block 10 ... Storage space 11 ... Peripheral wall 12 ... Opposite connecting face 13 ... Surface plate part 14 ... End face wall 15 ... Planar part 16 ... Curved part 17 ... Horizontal part 18 ... Welding rib 19 ... Vertical wall DESCRIPTION OF SYMBOLS 21 ... Projection 22 ... Insertion recessed part 23 ... Electrode window 24 ... Groove-shaped recessed part 30 ... Insertion space 31 ... Locking hook 31a ... Locking part 32 ... Locking receiving part 33 ... Stopping pressing part 41 ... Electrode terminal 42 ... Signal Terminal 45 ... Lead plate 46 ... Lead plate 50 ... Ultrasonic horn 51 ... Pressing surface 55 ... Base

Claims (6)

A battery pack comprising a battery that can be charged and discharged, and an outer case containing the battery,
The outer case is composed of a first case and a second case made of plastic by connecting opposing connecting surfaces provided along the outer periphery, and providing a storage space for the battery therein.
The opposing connection surfaces of the first case and the second case are formed by connecting the first case to the second case via a locking hook in a welding region formed by ultrasonic welding and a non-welding region where ultrasonic welding is not performed. It is connected to each other with a locking connecting part connected to the case,
The locking hook is provided on the first case, has a locking portion that extends to the inner surface of the second case and is locked to the inner surface of the second case,
The second case is provided with an engagement receiving portion on the inner surface for guiding the engagement portion of the engagement hook,

In the locking connection portion, the locking hook of the first case is hooked on the locking receiving portion of the second case, and the first case and the second case are connected ,
The opposing connection surfaces of the first case and the second case are arranged on the side surface of the battery, and the opposing connection surfaces on both sides are used as the welding region.
Battery pack, characterized in that the intermediate portion of the counter-coupling surface formed by arranging the electrode surface side of the battery as the weld region, comprising an end portion and said locking connection. The battery pack according to claim 1,
The battery pack according to claim 1, wherein the outer case is provided with the locking connection portion at a corner portion of the opposing connection surface. The battery pack according to claim 1 or 2 ,
The battery is a cylindrical battery or a prismatic battery having a curved portion on a side surface,
The first case and the second case are formed by connecting a curved portion formed along the outer side of the battery on both sides of the flat portion, and a surface plate portion formed on both ends of the surface plate portion. battery pack, characterized in that comprising the end wall formed by providing a part. The battery pack according to claim 3 , further comprising:
The exterior case houses the circuit board in contact with the end face wall inside the end face wall,

An insertion space for the locking hook is provided between an end of the circuit board and the inner surface of the exterior case, and the locking hook disposed in the insertion space is disposed in the same plane as the circuit board. A battery pack characterized by comprising: The battery pack according to any one of claims 1 to 4 , further comprising:
A battery holder for arranging the battery stored in the outer case at a fixed position of the storage space;
The battery pack, wherein the battery holder includes a retaining pressing portion that is located on a back surface of the locking hook and prevents the locking portion from coming off from the locking receiving portion in the locking connection portion. . The battery pack according to claim 5 ,
The retaining pressing portion is a projecting piece projecting from the end surface of the battery holder toward the inner surface of the second case, and the projecting piece is elastically deformed, so that the locking portion is separated from the inner surface of the second case. A battery pack, wherein the battery pack is guided between the pressing portion and the latch receiving portion.

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