JP5084301B2 - Pack battery - Google Patents

Description

  The present invention relates to a battery pack in which a rectangular battery thinner than a width is housed in an outer case.

  A prismatic battery pack battery is conveniently used by being mounted on various portable electric devices. In particular, it is an optimal shape for an electric device such as a mobile phone or PDA that needs to be thinned as a whole. In order to make this type of battery pack lighter and thinner, a structure has been developed in which only one side of a prismatic battery is placed in an outer case covered with a surface plate. (See Patent Document 1)

  As shown in FIG. 1, the battery pack of Patent Document 1 has a structure in which an outer case 91 into which a battery core 90 is placed is provided with a peripheral wall 93 around a surface plate 92. Furthermore, this battery pack is provided with an eaves 94 on one peripheral wall 93 of the outer case 91 and an insertion groove 95 on the inner side. The insertion part 96 of the battery core 90 is inserted into the insertion groove 95 and placed in a fixed position. Yes.

Furthermore, a battery pack having a shape in which a step is provided on one side of the outer periphery has been developed so that the battery pack can be set in a specific posture on an electric device and because a useless space is not provided as much as possible. (See Patent Documents 2 and 3)
JP 2006-164559 A JP 2004-185819 A JP 2004-63383 A

  Since these battery packs are provided with a step in the portion where the output terminal is provided, the battery pack has a feature that it can identify the posture set in the electric device and prevent reverse mounting. However, since the step portion is formed inside the outer case, the battery core cannot be smoothly inserted into the outer case. This is because, as shown in FIG. 2, the battery core 80 collides with the stepped protrusion 83 protruding from the inner surface of the outer case 81 by the stepped portion 82 and cannot be inserted smoothly. Further, the plastic outer case 81 having the stepped portion 82 has a drawback that it is difficult to realize a sufficient strength by forming the stepped portion 82 thinly.

  The present invention has been developed for the purpose of solving this drawback. An important object of the present invention is a battery pack in which a battery core can be smoothly inserted into a stepped outer case and efficiently assembled, and the stepped portion of the outer case can be made tough structure while the outer case is thinly molded with plastic. Is to provide.

The battery pack of the present invention has the following configuration in order to achieve the aforementioned object.
In the battery pack, a battery core 20 formed by connecting the output terminal 6 to the rectangular battery 2 is housed in the outer case 1. The outer case 1 is made of plastic, and first, second, third, and fourth peripheral walls that cover the outer periphery of the battery core 20 along the periphery of the rectangular surface plate 10 that covers the flat surface 2a of the rectangular battery 2. 11 is integrally formed, and a battery core 20 is housed in a box-shaped outer case 1 composed of a surface plate 10 and a peripheral wall 11. Further, the first peripheral wall 11 </ b> A of the outer case 1 is provided with eaves 13 along the side edge on the side opposite to the surface plate 10, and the inner side serves as the insertion groove portion 14 of the battery core 20. Furthermore, the surface plate 10 of the outer case 1 is provided with a stepped protrusion 15 that protrudes inside the insertion groove 14 along the connecting portion with the first peripheral wall 11A. The battery core 20 inserted into the insertion groove 14 of the outer case 1 is provided with a fitting recess 22 for guiding the step protrusion 15 in the insertion portion 21 guided by the insertion groove 14. On the inner surface of the surface plate 10 of the outer case 1, an inductive rib 23 having an upward slope toward the stepped convex portion 15 is integrally formed on the plastic outer case 1, and the battery is formed along the inductive rib 23. The insertion part 21 of the core 20 is guided to the insertion groove part 14.

  In the battery pack according to claim 2 of the present invention, in addition to the configuration of claim 1, the battery core 20 has the output terminal 6 fixed to the outer peripheral surface of the insertion portion 21 guided by the insertion groove portion 14. An electrode window 17 for exposing the terminal 6 to the outside of the exterior case 1 is opened in the first peripheral wall 11A.

  The battery pack according to claim 3 of the present invention has, in addition to the configuration of claim 1, the battery core 20 has a misalignment prevention recess 16 for fitting the guide rib 23 to prevent misalignment. The guide rib 23 is guided to the prevention recess 16, and the guide rib 23 prevents the displacement of the battery core 20.

  The battery pack of the present invention is characterized in that a battery core can be smoothly inserted into an outer case having a step and can be assembled efficiently. That is, the battery pack according to the present invention is provided with a step protrusion on the surface plate of the outer case along the connecting portion with the first peripheral wall, and the inner surface of the surface plate climbs toward the step protrusion. This is because a gradient guiding rib is provided. The outer case can guide the insertion portion of the battery core to the insertion groove along the guiding rib provided on the inner surface of the surface plate. For this reason, the corner portion of the battery core can be smoothly inserted into the fixed position with the guiding rib without colliding with the stepped convex portion of the surface plate.

  Further, the battery pack of the present invention can also realize a feature that the stepped portion of the outer case can be made tough structure while the outer case is thinly formed of plastic. This is because a guide rib with an ascending gradient toward the stepped convex portion is integrally formed on the inner surface of the surface plate in a plastic outer case.

  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, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  A battery pack according to an embodiment of the present invention is shown in FIGS. 3 and 4 are perspective views of the battery pack as viewed from the surface plate 10 side of the outer case 1, FIG. 5 is a perspective view of the battery pack with the insulating sheet 3 attached to the outer case 1, and FIG. FIG. 7 is a perspective view showing a state in which the battery core 20 is inserted into the outer case 1, and FIGS. 8 and 9 are perspective views of the battery core 20 as viewed from above and below. The battery pack shown in these drawings has a battery core 20 including a prismatic battery 2 and an output terminal 6 for taking out the positive and negative electrodes of the prismatic battery 2 in the exterior case 1. The prismatic battery 2 is a secondary battery in which the thickness (t) is thinner than the width (W) and the outer shape is a square. In this specification, the outer periphery of a square battery shall mean the outer periphery of the front and back which is the maximum surface of a square battery. Further, the flat surface of the prismatic battery is a surface that can be seen from the thickness direction, which is the vertical direction in FIGS. 8 and 9, and is the maximum configured by the width (W) and the length (L) in FIG. 9. A surface.

  The square 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 square battery as a lithium ion battery or a polymer battery. The square battery may be a battery other than these batteries, such as a nickel metal hydride battery or a nickel cadmium battery.

  The outer case 1 is manufactured by integrally molding the whole with plastic. For example, polycarbonate resin is used as the plastic. The outer case 1 can be reduced in size by setting the plate thickness to 0.3 mm. However, the plastic of the exterior case may be a plastic in which fibers such as glass fibers and carbon fibers are embedded and reinforced, such as PPS (polyphenylene sulfite). PPS has extremely excellent strength. PPS can be reinforced with fibers to improve impact strength. Furthermore, since PPS is excellent in flame retardancy, for example, when PPS is used as the material of the exterior case, even if the plate thickness is reduced to 0.4 mm, the flame retardancy defined by the UL standard etc. Can meet the criteria. Therefore, the PPS can be used for a battery pack for a special purpose that requires the UL standard, and can reduce the size of the battery pack by reducing the thickness of the outer case while maintaining flame retardancy.

  The prismatic battery 2 is assembled in the state of the battery core 20 and stored in the outer case 1. The battery core 20 connects the circuit board 4 in a fixed position to the rectangular battery 2 via the board holder 5. The circuit board 4 fixes the output terminal 6. The output terminal 6 is exposed to the outside from the electrode window 17 opened in the first peripheral wall 11 </ b> A of the exterior case 1.

  In the battery core 20, the substrate holder 5 is disposed between the circuit substrate 4 and the square battery 2. The substrate holder 5 is formed by integrally molding an insulating material such as plastic. The circuit board 4 has an output terminal 6 fixed on the surface. The circuit board 4 is mounted with a battery protection circuit (not shown). The protection circuit is a circuit that protects the overcurrent of the prismatic battery 2 or PTC, or a circuit that prevents overcharge or overdischarge of the prismatic battery 2. In the illustrated battery pack, the circuit board 4 is connected to the square battery 2 with the PTC as the protective element 7 as one connection lead 8. However, a protective element such as a PTC or a thermal fuse can be mounted on the circuit board, and both ends of the circuit board can be connected to the square battery with lead plates. In the battery pack, the circuit board can be connected to the prismatic battery by using a protective element as a temperature fuse instead of the PTC and one connection lead as a temperature fuse.

  The substrate holder 5 is sandwiched between the circuit substrate 4 and the square battery 2 and is disposed at a fixed position. As shown in the sectional views of FIGS. 10 and 11, the substrate holder 5 has the circuit board 4 connected to one surface and the prismatic battery 2 connected to the other surface. The board holder 5 connects the circuit board 4 in a fixed position with the fitting structure. Further, a concave portion 24 that guides the curved surface of the prismatic battery 2 is provided and connected to a fixed position of the prismatic battery 2.

  The circuit board 4 is connected to the prismatic battery 2 via a pair of connection leads 8 and 9 connected to the positive and negative electrodes of the prismatic battery 2. The connection lead 8 is connected to one electrode of the rectangular battery 2 through the protective element 7. The battery core 20 can connect the circuit board 4 to the rectangular battery 2 using the protective element 7 as the connection lead 8.

  The connection lead 8 connected to the convex electrode 2B is insulated from a sealing plate (not shown). This is because the sealing plate and the convex electrode 2B are different electrodes. The lithium ion secondary battery which is the prismatic battery 2 uses the convex electrode 2B as a negative electrode and the sealing plate and the outer can 2A as a positive electrode. The outer can 2A of the prismatic battery 2 is a metal case. In the illustrated battery core 20, the connection lead 8 connected to the convex electrode 2 </ b> B serves as the protection element 7, so that insulation is provided between the protection element 7, which is the connection lead 8 connected to the convex electrode 2 </ b> B, and the sealing plate. A plate 25 is provided to insulate the connection lead 8 from the sealing plate. The insulating plate 25 is bonded or fixed to the end face of the prismatic battery 2 via a double-sided adhesive tape to insulate the connection leads 8 connected to the convex electrode 2B from the sealing plate. The insulating plate can also be formed integrally with a plastic substrate holder. The connection leads 8 and 9 are connected to the electrodes of the prismatic battery 2 by resistance spot welding or laser welding. Further, resistance spot welding, laser welding, or soldering is used to connect to the circuit board 4.

  As shown in the cross-sectional views of FIGS. 10 to 12, the battery core 20 is provided with a fitting recess 22 in which the width of the circuit board 2 is narrower than the thickness of the rectangular battery 2. In these drawings, the battery core 20 is provided with a fitting recess 22 on the lower surface of the insertion portion 21 guided by the insertion groove portion 14 of the outer case 1. The outer case 1 is provided with an insertion groove portion 14 for guiding the insertion portion 21 of the battery core 20 inside the first peripheral wall 11A. The stepped protrusion 15 provided on the inner surface of the outer case 1 is disposed in the fitting recess 22 of the battery core 20. In these drawings, the battery core 20 has the circuit board 4 disposed above the center of the prismatic battery 2, and is provided with a fitting recess 22 on the lower surface of the insertion portion 21. The battery core 20 shown in the figure is provided with a fitting recess 22 in the substrate holder 5. The substrate holder 5 provided with the fitting recess 22 is shown in FIGS. The battery core 20 in these drawings is provided with an insertion portion 21 to be inserted into the insertion groove portion 14 of the outer case 1, and the circuit board 4 is disposed on the distal end surface of the insertion portion 21. The insertion portion 21 of the battery core 20 is disposed so as to be shifted upward from the vertical center of the rectangular battery 2 in the cross-sectional views of FIGS. 10 to 12, and a fitting recess 22 is provided below the insertion portion 21. . 8 and 9 are perspective views in which the cross-sectional views of FIGS. 10 to 12 are turned upside down. Therefore, the fitting recess 22 is positioned above the insertion portion 21 in FIGS.

  The circuit board 4 is connected to the board holder 5 with a fitting structure and is arranged at a fixed position. The circuit board 4 and the substrate holder 5 shown in the figure have a structure in which a plurality of positioning projections 5A are provided on the side edges of the substrate holder 5, and the positioning recesses 4A into which the positioning projections 5A are inserted are provided on the circuit board. The circuit board 4 is connected to a fixed position of the substrate holder 5 by being arranged in a state where the positioning convex part 5A and the positioning concave part 4A are fitted. The substrate holder 5 shown in the figure is provided with positioning convex portions 5A located at the four corners and side surfaces of the circuit board 4, and the positioning convex portions 5A are inserted into the positioning concave portions 4A provided at the four corners and side surfaces of the circuit board 4. Thus, the vertical and horizontal directions of the circuit board 4 are positioned. Further, the circuit board 4 is connected so as not to be detached from the board holder 5 via connection leads 8 and 9 connected to both ends. However, the circuit board and the board holder can be connected to each other in place by another fitting structure or locking structure. For example, the fitting structure of the circuit board and the substrate holder is not shown, but a positioning wall is provided along one side edge of the substrate holder, and a positioning protrusion is provided in the central portion so as to protrude in the vertical direction. It is also possible to place the circuit board in contact with the positioning wall and the positioning convex portion so as to connect the circuit board to a fixed position of the board holder.

  The circuit board 4 is connected to the prismatic battery 2 via the connection leads 8 and 9 in a state where the circuit board 4 is connected to a fixed position of the substrate holder 5. When the circuit board 4 is connected to the square battery 2, the board holder 5 is sandwiched between the circuit board 4 and the square battery 2 and arranged at a fixed position. The above battery core 20 connects the substrate holder 5 and the circuit board 4 to each other in a fixed position, and connects the circuit board 4 to the rectangular battery 2 via the connection leads 8 and 9. 5 and the prismatic battery 2 can be connected so that their relative positions do not deviate from each other.

  The outer case 1 is made of plastic, and a rectangular peripheral wall 11 surrounding the outer periphery of the battery core 20 is integrally formed around a rectangular surface plate 10 that covers one side of the prismatic battery 2. The outer case 1 has a box shape with the surface plate 10 and the peripheral wall 11, and the battery core 20 is accommodated in the outer case 1. The surface plate 10 covers one flat surface 2 a of the rectangular battery 2 of the battery core 20. The outer case 1 does not cover the flat surfaces 2 a on the front and back sides of the rectangular battery 2 of the battery core 20. The flat surface 2 a that is not covered with the surface plate 10 is in the opening 12 of the peripheral wall 11 and is covered with the insulating sheet 3.

  The rectangular peripheral wall 11 is composed of four sides including first, second, third, and fourth peripheral walls. An electrode window 17 is provided on the first peripheral wall 11A, which is one of the four sides. The electrode window 17 exposes the output terminal 6 of the battery pack to the outside. Therefore, the output terminal 6 is disposed inside the electrode window 17. The output terminal 6 is fixed to the circuit board 4 and disposed inside the electrode window 17.

  11 A of 1st surrounding walls are provided with the eaves 13 integrally shape | molding. The eaves 13 are provided along the side edge opposite to the side edge provided by connecting the surface plate 10, along the upper edge in FIG. 7. 11 A of 1st surrounding walls provide the insertion groove part 14 in the inner side by the eaves 13 and the surface plate 10. As shown in FIG. The insertion portion 21 of the battery core 20 is inserted into the insertion groove 14, and the battery core 20 is disposed at a fixed position of the outer case 1. The inner surface of the eaves 13 has a shape along the surface of the insertion portion 21 of the battery core 20.

  Furthermore, the surface plate 10 of the outer case 1 is provided with a stepped protrusion 15 that protrudes inside the insertion groove 14 along the connecting portion with the first peripheral wall 11A. The step protrusion 15 is formed into a shape that is inserted into the insertion recess 22 of the battery core 20. Furthermore, as shown in the perspective view of FIG. 7, the inner surface of the surface plate 10 is provided with a leading-in rib 23 having an upward slope toward the stepped convex portion 15. The guide ribs 23 are integrally formed on the plastic outer case 1. As shown in FIG. 10, the outer case 1 guides the insertion portion 21 of the battery core 20 to the insertion groove portion 14 along the guiding rib 23. The outer case 1 is preferably provided with a plurality of guide ribs 23 arranged in parallel. The outer case 1 of FIG. 7 has three rows of guiding ribs 23 on both side portions and the central portion of the stepped convex portion 15. Further, the guiding rib 23 makes the inclination angle α with respect to the surface plate 10 smaller than, for example, 45 degrees so that the battery core 20 can be smoothly guided to the insertion groove portion 14. However, if the inclination angle α of the guiding rib 23 is reduced, the guiding rib becomes longer. Therefore, the inclination angle α is preferably 15 degrees to 45 degrees, more preferably 30 degrees to 45 degrees. The guiding rib 23 provided toward the step convex portion 15 is made equal to the height of the step convex portion 15 at the boundary with the step convex portion 15. The battery core 20 is disposed at a fixed position of the outer case 1 with the insertion portion 21 inserted into the insertion groove portion 14 along the guiding rib 23. The battery core 20 arranged in the outer case 1 arranges the circuit board 4 at a fixed position, and arranges the output terminal 6 of the circuit board 4 at a fixed position inside the electrode window 17.

  The battery core 20 shown in FIGS. 8 and 9 is provided with a misalignment prevention recess 16 in a portion where the guiding rib 23 is inserted in a state where the battery core 20 is disposed at a fixed position of the outer case 1. The guide rib 23 is guided to the misregistration preventing recess 16, and the position deviation of the battery core 20 is prevented by the guide rib 23. FIG. 13 is a cross-sectional view showing a state in which the lead-in rib 23 is guided to the misalignment prevention recess 16 in a state where the battery core 20 is disposed at a fixed position of the outer case 1. As shown in this figure, the guiding ribs 23 are guided by the misalignment prevention recesses 16 to prevent lateral displacement of the battery core 20 with respect to the outer case 1. This is because the guiding rib 23 abuts against the inner surface of the misregistration prevention recess 16 against the lateral displacement of the battery core 20 and the lateral displacement is prevented. FIG. 11 shows a state in which the guiding rib 23 is guided into the misalignment prevention recess 16.

  In the battery pack, the insertion portion 21 of the battery core 20 is inserted into the insertion groove portion 14 of the first peripheral wall 11 </ b> A, and the battery core 20 is disposed at a fixed position of the outer case 1. In the outer case 1 shown in FIGS. 11 and 12, the eaves 13 have a width that allows the insertion portion 21 of the battery core 20 provided by the substrate holder 5 to be inserted. In the battery pack shown in these figures, a recessed surface 18 for attaching the insulating sheet 3 is provided on the outer surface of the eaves 13, and the insulating sheet 3 bonded to the recessed surface 18 is bonded to the surface of the battery core 20. The recessed surface 18 of the eaves 13 is on the same plane as the flat surface 2a of the rectangular battery 2 of the battery core 20 housed in the exterior case 1, and the insulating sheet 3 is bonded in a planar shape.

  In the battery pack, the battery core 20 is put in the outer case 1 and the insulating sheet 3 such as a label is attached to close the opening 12 of the peripheral wall 11. The insulating sheet 3 is bonded to one side of the square battery 2 and the outer case 1. In the battery pack, the insulating sheet 3 is bonded to the four sides of the peripheral wall 11 of the outer case 1, and in the battery pack in FIG. 5, a part of the insulating sheet 3 is protruded to detach the battery pack from the electrical device 30. The knob 3A is used.

  The insulating sheet 3 is a flexible plastic sheet or label. The insulating sheet 3 is bonded to the prismatic battery 2 and the outer case 1 via an adhesive, or is bonded via an adhesive layer.

  Furthermore, the prismatic battery 2 placed in the peripheral wall 11 of the outer case 1 can be fixed by adhering to the inner surface of the surface plate 10 with an adhesive or using a double-sided adhesive tape. The adhesive or the double-sided adhesive tape adheres the end of the prismatic battery 2 opposite to the first peripheral wall 11 </ b> A or the peripheral edge of the prismatic battery 2 to the inner surface of the surface plate 10, or adheres the entire surface to the surface plate 10. .

1 is an exploded perspective view of a battery pack previously filed by the present applicant. It is an expanded sectional view which shows the state which inserts a battery core in the exterior case of the conventional battery pack. It is the perspective view which looked at the battery pack concerning one Example of this invention from the surface plate side of the exterior case. FIG. 4 is a rear perspective view of the battery pack shown in FIG. 3. It is a perspective view which shows the state which adhered the insulating sheet to the exterior case of the battery pack shown in FIG. It is sectional drawing which shows the state which set the battery pack shown in FIG. 5 to the electric equipment. It is a perspective view which shows the state which inserts a battery core in an exterior case. It is a perspective view of a battery core. It is the perspective view which reversed the battery core shown in FIG. It is an expanded sectional view which shows the state which inserts a battery core in an exterior case, Comprising: It is a figure corresponded in the AA line cross section of FIG. It is an expanded sectional view which shows the state which inserted the battery core in the exterior case, Comprising: It is a figure corresponded in the AA line cross section of FIG. It is an expanded sectional view which shows the state which inserted the battery core in the exterior case, Comprising: It is a figure corresponded in the BB line cross section of FIG. It is sectional drawing which shows the state which guides a guide rib to a position shift prevention recessed part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Exterior case 2 ... Square battery 2A ... Exterior can 2B ... Convex electrode
2a ... Flat surface 3 ... Insulating sheet 3A ... Knob 4 ... Circuit board 4A ... Positioning recess 5 ... Substrate holder 5A ... Positioning projection 6 ... Output terminal 7 ... Protection element 8 ... Connection lead 9 ... Connection lead 10 ... Surface plate DESCRIPTION OF SYMBOLS 11 ... Peripheral wall 11A ... 1st surrounding wall 12 ... Opening part 13 ... Eaves 14 ... Insertion groove part 15 ... Level | step difference convex part 16 ... Misalignment prevention recessed part 17 ... Electrode window 18 ... Recessed surface 20 ... Battery core 21 ... Insertion part 22 ... Fitting Recessed part 23 ... Guide rib 24 ... Recessed part 25 ... Insulating plate 30 ... Electric equipment 80 ... Battery core 81 ... Exterior case 82 ... Stepped part 83 ... Stepped convex part 90 ... Battery core 91 ... Exterior case 92 ... Surface plate 93 ... Peripheral wall 94 ... eaves 95 ... insertion groove 96 ... insertion

Claims (3)

A battery pack in which a battery core (20) formed by connecting an output terminal (6) to a prismatic battery (2) is housed in an outer case (1),
The outer case (1) is made of plastic, and the first and the outer covers of the battery core (20) are covered along the periphery of the rectangular surface plate (10) covering the flat surface (2a) of the prismatic battery (2). The second, third and fourth peripheral walls (11) are integrally formed, and a battery core (20) is provided on a box-shaped outer case (1) comprising a surface plate (10) and a peripheral wall (11). )
Further, the first peripheral wall (11A) of the outer case (1) is provided with a ridge (13) along the side edge opposite to the surface plate (10), and the inner side is an insertion groove ( 14), and the surface plate (10) of the outer case (1) has a stepped protrusion (15) protruding inside the insertion groove (14) along the connecting portion with the first peripheral wall (11A). )
The battery core (20) inserted into the insertion groove (14) of the outer case (1) is fitted into the insertion part (21) guided to the insertion groove (14) to guide the stepped protrusion (15). Provided with a recess (22),
Provided on the inner surface of the surface plate (10) of the outer case (1) by integrally forming a guiding rib (23) with an upward slope toward the stepped convex portion (15) into the plastic outer case (1). The battery pack is configured to guide the insertion portion (21) of the battery core (20) to the insertion groove portion (14) along the guide rib (23).   The battery core (20) fixes the output terminal (6) to the outer peripheral surface of the insertion portion (21) guided by the insertion groove (14), and this output terminal (6) is connected to the exterior of the outer case (1). The battery pack according to claim 1, wherein the electrode window (17) exposed to the opening is opened in the first peripheral wall (11 </ b> A).   The battery core (20) has a misalignment prevention recess (16) that prevents the misalignment by fitting the guide rib (23), and guides the guide rib (23) into the misalignment prevention recess (16). The battery pack according to claim 1, wherein the lead-in rib (23) prevents displacement of the battery core (20).

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