JP4953678B2 - Pack battery - Google Patents

Description

  The present invention relates to a battery pack in which a plurality of batteries are housed to form an inner pack, and the inner pack is placed in an outer case, and more particularly to a battery pack having excellent impact strength.

  The battery pack is required to have impact strength. In particular, a battery pack that becomes heavier due to an increase in the number of batteries stored therein is required to have a characteristic that does not fail due to a large impact such as dropping. In order to improve the impact strength, the battery pack containing a large number of batteries has a double structure. (See Patent Documents 1 and 2)

In this battery pack, the battery is stored in an inner case or a holder to form an inner pack, and the inner pack is stored in an outer case. The battery pack having this structure can improve the impact strength by making the case a double structure.
JP-A-2005-317459 JP 2005-197192 A

  However, even if the case has a double structure, if the number of stored batteries increases or the impact is large, there are problems such as deformation of the outer case and the inner case. In order to eliminate this drawback, the present inventors have developed a battery pack having a structure in which a soft urethane foam sheet is disposed as a cushioning material between an inner case and an outer case. Since this battery pack absorbs the impact of the outer case by the cushion material, the impact resistance strength can be further improved. However, the soft synthetic resin foam cushioning material deteriorates over time with age, becomes brittle, hardens into a crushed state, and cannot absorb the impact. Furthermore, since a cushion material made of a synthetic resin foam is bonded to the surface of the inner case with an adhesive layer or an adhesive, it takes time to attach the cushion material. In addition, since a cushion material different from the inner case and the outer case is used to absorb the impact, the cost of parts increases. Furthermore, the cushion material requires a considerable thickness and area to absorb the impact of the outer case. Since a thick and large-area cushioning material is provided between the inner case and the outer case, it is necessary to increase the gap for arranging the cushion material, which has the disadvantage of increasing the outer case.

  The present invention has been developed for the purpose of solving such drawbacks. An important object of the present invention is to achieve excellent impact resistance while minimizing the deterioration of impact strength over time, and to reduce the space for disposing members that absorb impact compared to cushion materials. Thus, there is no need to make the outer case small, and it is not necessary to fix another part like a cushion material by special bonding, and a battery pack that can be easily and easily mass-produced efficiently and inexpensively is provided. There is.

The battery pack of the present invention is a battery pack comprising an inner pack 3 for storing a plurality of batteries 1 in a fixed position of an inner case 2, and an outer case 4 for storing the inner pack 3. A shock absorbing gap 5 is provided between the case 4 and one end of the shock absorbing gap 5 is connected to the inner pack 3 or the outer case 4 and elastically deformed by the shock of the battery pack. An elastic spring 6 made of hard plastic or metal that absorbs the energy of the inside is disposed, and the inner pack 3 includes a cap 20 that is attached to the inner case 2, and the cap 20 is arranged in the shock absorbing gap 5. The provided elastic spring 6 can be provided in an integral structure.

The battery pack of the present invention has an advantage that the impact strength over time can be extremely reduced while realizing excellent impact resistance. It battery pack of the present invention, a plurality of batteries housed in a fixed position of the inner case, provided with a shock-absorbing gaps between the inner case and outer case housing the inner case, this shock-absorbing gaps It has a connecting part that connects one end to the inner case or the outer case, and the other end is not connected to the inner case or the outer case, and is elastically deformed by the impact of the battery pack to absorb the energy of the impact. An elastic spring made of hard plastic or metal is disposed , and further, a deformation gap is provided between the elastic spring and the inner case or the outer case, and the connecting portion of the elastic spring is in the thickness direction of the elastic spring. This is because it is located between the shock absorbing gap and the deformation gap . This structure absorbs the impact by elastically deforming an elastic spring made of hard plastic or metal, so that it deteriorates with time like a conventional synthetic resin foam cushioning material and becomes brittle and the impact resistance is lowered. Can be effectively prevented, and excellent impact resistance can be realized over a long period of time.

  Furthermore, the battery pack of the present invention does not have a thick and large area cushioning material arranged in the gap between the inner case and the outer case as in the case of the conventional battery pack, and the impact is applied with a small elastic spring compared to the cushioning material. Since it can be absorbed, there is a feature that the outer case can be made smaller by reducing the space for arranging the elastic spring. In particular, the battery pack according to the present invention does not require a cushioning material different from the inner case and the exterior case, so that the cost of parts can be reduced, and the labor for bonding the cushioning material can be omitted, easily and easily. There is also a feature that mass production is efficient and inexpensive.

Furthermore, packs battery of the present invention, the inner shape of the outer shape and the outer casing of the inner pack as rectangular, since an elastic spring shock-absorbing gaps all around four sides or six sides of the entire surface of the rectangular parallelepiped, the pack The elastic spring can be elastically deformed against an impact acting on the battery from the surroundings, and the energy of the impact can be effectively absorbed. In particular, the structure in which the elastic spring is provided in the six shock absorbing gaps, which is the entire surface of the inner case of the rectangular parallelepiped, has a feature that the elastic spring can absorb the impact from any direction of the battery pack.

Furthermore, it packs battery of the present invention, since the integrally formed structure elastic spring the inner casing can be provided with a resilient spring in the step of manufacturing the inner case. For this reason, the manufacturing process can be simplified and mass production can be efficiently and inexpensively performed. Further, since the elastic spring can be disposed in the shock absorbing gap while the inner case containing the battery is housed in the outer case, there is also a feature that it can be assembled very efficiently.

Furthermore, packs battery of the present invention, since the inner pack deposited the cap are integrally formed structure inner case an elastic spring, by mounting a cap on the inner casing, the elastic spring very easily It can be provided at a fixed position. Further, when the elastic spring is damaged or becomes defective, the elastic spring can be disposed at low cost by replacing only the cap.

  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.

  The battery pack of the first embodiment shown in FIGS. 1 to 6 and the battery pack of the second embodiment shown in FIGS. 7 to 13 are an inner pack 3 in which a plurality of batteries 1 are arranged and stored. And an outer case 4 for storing the inner pack 3. In the battery pack shown in these drawings, an impact absorbing gap 5 is provided between the inner pack 3 and the outer case 4 so that the inner pack 3 and the outer case 4 connected to each other can move relatively. . Further, the battery pack is provided with an elastic spring 6 having one end connected to the inner pack 3 in the shock absorbing gap 5. In this battery pack, the elastic spring 6 is elastically deformed to cause the inner pack 3 and the outer case 4 to move relative to each other, so that the elastic spring 6 absorbs the impact of the outer case 4.

  As shown in FIG. 4, the inner pack 3 shown in FIGS. 2 and 3 is provided inside a plurality of rechargeable batteries 1, an inner case 2 that houses the batteries 1 in a fixed position, and the inner case 2. Circuit board 7.

  The inner case 2 includes a rectangular battery case 8 that houses the battery 1 therein, and a battery holder 9 that is disposed between the batteries 1 and places the battery 1 at a fixed position. The battery case 8 is manufactured by molding plastic. In this inner pack 3, a battery case 8 that is the inner case 2 is formed of hard plastic, and an elastic spring 6 is formed integrally with the battery case 8 that is the inner case 2. However, the inner case can be made of a metal case and a metal elastic spring can be provided integrally with the battery case. Further, the inner case can be formed into an integral structure by molding the battery case from plastic and inserting one end of the elastic spring into the battery case. The elastic spring can be made of a material different from that of the battery case. The inner case can be manufactured, for example, by inserting a metal elastic spring into a plastic battery case. Further, the inner case can be fixed by connecting one end of the inner case to the battery case as a separate member from the battery case without having an elastic spring as an integral structure.

  In the illustrated inner case 2, the battery case 8 includes a main body case 8 </ b> A that is a rectangular box shape and a lid case 8 </ b> B that closes an opening of the main body case 8 </ b> A. The main body case 8A accommodates the batteries 1 in a multi-stage and multi-row arrangement in a parallel posture. The lid case 8B is bonded or welded to the main body case 8A, or is connected by a fitting structure to close the opening of the main body case 8A.

  The main body case 8A having a rectangular box shape is provided with elastic springs 6 so as to protrude outwardly from four peripheral walls provided around the bottom plate, in other words, around the bottom plate. The inner pack 3 can absorb an impact in a direction in which the four elastic springs 6 are elastically deformed. The elastic spring 6 has a plate shape that can be elastically deformed by an impact applied to the battery pack. The elastic spring 6 is provided with a deformation gap 10 between the inner case 2 and one end thereof is connected to the main body case 8A. As shown in FIG. 5, the elastic spring 6 is disposed in the shock absorbing gap 5 so as to be in contact with the inner surface of the outer case 4. When an impact is applied to the outer case 4 such as when the battery pack is dropped, the elastic spring 6 is elastically deformed so as to change the interval of the deformation gap 10. The elastic spring 6 is elastically deformed and absorbs impact energy. Since the elastic spring 6 is elastically deformed when an impact is applied, the impact of the outer case 4 is absorbed by the elastic spring 6 and the impact applied to the inner pack 3 that houses the battery 1 is reduced.

  The degree to which the elastic spring 6 is deformed by the impact received by the battery pack is adjusted by the hardness of the hard plastic forming the elastic spring 6 and the shape of the elastic spring 6. When the battery pack becomes heavier, the impact such as dropping becomes stronger. Therefore, in a heavy battery pack, the hard plastic forming the elastic spring 6 is hardened, and the connecting portion and the whole of the elastic spring 6 are thickened so as to be deformed by a strong impact. On the other hand, since the light battery pack receives a small impact when dropped, the hard plastic forming the elastic spring 6 is made of a material that can be easily deformed, and the connecting portion and the whole are made thin so that the elastic spring 6 is also easily elastically deformed. Therefore, it can be deformed with a weak impact so that the impact can be absorbed effectively.

  The inner pack 3 includes a battery holder 9 in a battery case 8 and places the battery 1 at a fixed position. The battery holder 9 is manufactured by molding an insulating material such as hard or soft plastic. In the illustrated battery holder 9, fitting grooves 11 for fitting the battery 1 are provided on both surfaces at regular intervals. The battery 1 is guided to the fitting groove 11, and the batteries 1 are arranged in two rows and seven rows and arranged at fixed positions.

  Further, the inner pack 3 of FIG. 4 is arranged in the battery case 8 with the circuit board 7 placed in the board holder 12. The substrate holder 12 has a rectangular box shape, and the circuit board 7 is put inside and filled with an insulating resin such as urethane to firmly fix the circuit board 7. The circuit board 7 is mounted with a control circuit (not shown) that controls the battery 1 to prevent overcharge and overdischarge. The circuit board 7 is connected to the battery 1 via lead plates 13 connected to electrodes at both ends of the battery. The substrate holder 12 is disposed so as to be sandwiched between the battery 1 and the circuit substrate 7.

The above inner pack 3 is assembled as follows.
(1) The battery 1 is placed in the fitting grooves 11 provided on both surfaces of the battery holder 9 and placed in a fixed position.
(2) In the above state, the lead plate 13 is connected to the electrode of the battery 1 by a method such as spot welding or laser welding.
(3) A battery holder 12 that accommodates the circuit board 7 is disposed in the battery 1 connected in two rows and seven rows, and the lead plate 13 connected to the battery 1 is connected to the circuit board 7. The core pack of the battery 1 is assumed.
(4) After the core pack of the battery 1 is put in the main body case 8A, the opening of the main body case 8A is closed by the lid case 8B, so that the inner pack 3 is obtained.

  The inner pack 3 manufactured as described above is stored in the outer case 4 shown in FIG. The outer case 4 is formed of plastic in a shape in which a rectangular parallelepiped box is divided into two by a peripheral wall. The exterior case 4 in FIG. 2 is partitioned by a partition wall 14 to provide a storage chamber 15 for the inner pack 3 and a storage chamber 17 for the output terminal 16. In the storage chamber 15 of the inner pack 3, an impact absorbing gap 5 is formed between the outer surface of the inner pack 3 and the inner surface of the outer case 4 in a state where the inner pack 3 is inserted, and an elastic spring is provided in the shock absorbing gap 5. 6 is arranged, and the elastic spring 6 is formed into an inner shape in contact with the inner surface.

  In the battery pack having the above structure, after the output lead 18 of the inner pack 3 is connected to the output terminal 16, the inner pack 3 and the output terminal 16 are placed in the storage chambers 15 and 17 that are separately partitioned. Thereafter, the outer case 4 is connected by a peripheral wall, and the inner pack 3 and the output terminal 16 are fixed in the outer case 4. The outer case 4 is connected to each other by welding, bonding, or fitting the contact edges of the peripheral walls.

  As described above, when the inner pack 3 is stored in the outer case 4, an impact absorbing gap 5 is formed between the inner pack 3 and the outer case 4 as shown in FIGS. 5 and 6. An elastic spring 6 is provided. One end of the elastic spring 6 is connected to the inner pack 3 and elastically contacts the inner surface of the outer case 4 in a surface contact state. As shown in FIG. 5, this battery pack is provided with elastic springs 6 on all four sides of the inner case 2, so that the elastic springs against impacts acting on the battery pack from the surroundings as indicated by arrows. 6 is elastically deformed to absorb impact energy.

  The elastic springs 6 provided on the four surfaces of the battery pack are impacts in the row direction of the batteries 1 (direction indicated by arrow A in FIG. 5) and impacts acting in the axial direction of the battery 1 (direction indicated by arrow B in FIG. 5). To absorb the shock of. In this battery pack, the elastic spring 6 does not absorb the impact in the direction indicated by the arrow C in FIG. This is because the elastic spring 6 is not provided on both surfaces of the inner case 2. In the battery pack of FIG. 6, the battery holder 9 can prevent the battery 1 from being damaged by an impact in the direction indicated by the arrow C. This is because the battery holder 9 supports the battery 1 in a wide area. However, the inner case can be provided with elastic springs on both surfaces (the bottom surface of the main body case and the upper surface of the lid case), and the elastic springs can be disposed on the entire surface of the six surfaces.

7 to 13, instead of providing the elastic spring 6 on the inner case 2, a cap 20 is attached to the inner case 2, and the elastic spring 6 is provided on the cap 20.
In the second embodiment described below, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The cap 20 is made of a hard plastic or metal plate that is elastically deformed by the impact of the battery pack and absorbs the energy of the impact, and is provided with an elastic spring 6 disposed in the impact absorbing gap 5 in an integral structure. The illustrated battery pack has caps 20 attached to both ends of the inner case 2. In this battery pack, the inner pack 3 can be placed inside the outer case 4 in a well-balanced manner with the caps 20 at both ends. Although not shown, the battery pack may have a structure in which a cylindrical cap is attached to an intermediate portion of the inner pack and an elastic spring is provided on the outer peripheral surface of the cap.

  The cap 20 in the figure is shaped like a square cylinder in which the side wall 22 is connected to the periphery of the end face plate 21 so that it can be connected to both ends of the square columnar inner pack 3, and the bottom of the cylinder portion 23 is closed by the end face plate 21. Molding. The cap 20 is connected to the inner case 2 by inserting the inner case 2 into the cylindrical portion 23 so that the inner shape of the cylindrical portion 23 including the four side walls 22 is substantially equal to the outer shape of the inner case 2. In order to connect the cap 20 to a fixed position of the inner case 2, three connecting arms 25 are provided on each of the four side walls 22 constituting the cylindrical portion 23. The connecting arm 25 is connected to the end face plate 21. The connecting arm 25 is provided with a slit 24 around the connecting portion so as to be elastically deformable with respect to the end face plate 21. Further, the connecting arm 25 is provided with a contact convex portion 26 that contacts the outer peripheral surface of the inner case 2 on the inner surface of the tip portion. The connecting arm 25 is configured to elastically deform the connecting portion with the end face plate 21, press the surface of the inner case 2 with the contact convex portion 26 at the tip, and cap the inner case 2 elastically. 20 is connected to a fixed position of the inner case 2.

  Two elastic springs 6 are provided on each of the four side walls 22 constituting the cylindrical portion 23. The elastic spring 6 is connected to the end face plate 21. The side wall 22 has a shape in which slits 24 are provided on both sides of the elastic spring 6, the elastic spring 6 is separated from the side wall 22 by the slit 24, and the elastic spring 6 is separated from the side wall 22 to be elastically deformed. As shown in FIGS. 12 and 13, the elastic spring 6 is inclined in a direction in which the tip is separated from the inner case 2, that is, in a direction approaching the inner surface of the outer case 4. The elastic spring 6 is elastically deformed at the connecting portion with the cap 20 and absorbs the impact of the battery pack.

  Furthermore, although not shown in the drawing, the elastic spring can be formed into a corrugated tip. This elastic spring can absorb the impact of the battery pack by elastically deforming the connecting portion with the cap and further deforming the corrugated portion at the tip, that is, elastically deforming in two steps. In this elastic spring, for example, the connecting portion with the cap is more easily deformed than the corrugated portion, and weak impact is absorbed by deformation of this portion. Further, the corrugated portion is less likely to deform than the connecting portion, and a strong impact is absorbed by the elastic deformation of the corrugated portion. The elastic spring 6 is deformed in two steps and can effectively absorb a strong impact from a weak impact. However, the elastic spring can also elastically deform only the corrugated portion at the tip to absorb the impact of the battery pack.

  The end plate 21 is provided with two pieces of elastic springs 6. The elastic spring 6 is connected to a boundary portion with the side wall 22 of the end face plate 21. This elastic spring 6 is provided with a slit 24 around the connecting portion so as to be separated from the end face plate 21 and elastically deformable. Further, the elastic spring 6 is inclined in a direction away from the end face plate 21 and in contact with the inner surface of the exterior case 4. Although not shown, this elastic spring can also have a shape that can be elastically deformed, with the tip portion being corrugated, similarly to the elastic spring on the side wall.

  The cap 20 in the figure is made of a hard plastic that absorbs impact energy, and an elastic spring 6 is integrally formed. With this structure, the elastic spring 6 can be easily provided on the cap 20. However, when the cap is formed of plastic, one end of the elastic spring can be inserted to form an integral structure. This elastic spring can be made of a material different from that of the cap. For example, the cap can be manufactured by inserting a metal elastic spring into a plastic end plate. Furthermore, the cap can be connected to the cap at one end as a separate member from the cap without having an elastic spring as an integral structure.

  The inner pack 3 that attaches the cap 20 to both ends of the inner case 2 is housed inside the outer case 4. In this battery pack, shock absorbing gaps 5 are provided on the entire six surfaces of the outer case 4 and the inner pack 3 that are rectangular parallelepipeds, and the elastic spring 6 is disposed on the entire six surfaces. The state in which the inner pack 3 is stored in the outer case 4 is shown in FIGS. As shown in these drawings, elastic springs 6 are disposed in impact absorbing gaps 5 provided on the six surfaces of the entire surface of the rectangular parallelepiped. For this reason, the impact from all directions of the battery pack can be absorbed by the elastic spring 6.

  In the battery pack of the embodiment described above, one end of the elastic spring 6 is connected to the inner pack 3. However, the battery pack of the present invention can also connect one end of the elastic spring to the exterior case. In this battery pack, one end of an elastic spring is connected to the inner surface of the outer case, the elastic spring is disposed in the shock absorbing gap, the elastic spring is elastically deformed, and the shock of the outer case is absorbed by the elastic spring. The elastic spring whose one end is connected to the inner surface of the outer case is formed by, for example, molding the outer case with a hard plastic or metal that is elastically deformed by an impact and absorbs the energy of the shock, and is integrally formed in the outer case. Can do. Furthermore, the elastic spring provided on the inner surface of the outer case can be formed into an integral structure by molding the outer case with plastic and inserting one end of the elastic spring into the inner surface. This elastic spring can be made of a material different from that of the outer case. This elastic spring is made of a hard plastic or metal plate that is elastically deformed by an impact and absorbs the energy of the impact. However, the elastic spring can be disposed in the shock absorbing gap by connecting one end to the inner surface of the outer case without being integrated with the outer case.

1 is a perspective view of a battery pack according to a first embodiment of the present invention. It is a disassembled perspective view of the battery pack shown in FIG. It is a perspective view of the inner pack of the battery pack shown in FIG. FIG. 4 is an exploded perspective view of the inner pack shown in FIG. 3. It is a partially expanded plan view which shows the internal structure of the battery pack shown in FIG. It is a vertical sectional view of the battery pack shown in FIG. It is a perspective view of the battery pack concerning the 2nd example of the present invention. It is a disassembled perspective view of the battery pack shown in FIG. It is a perspective view of the inner pack of the battery pack shown in FIG. FIG. 10 is an exploded perspective view of the inner pack shown in FIG. 9. It is a disassembled perspective view of the inner pack shown in FIG. It is a top view which shows the internal structure of the battery pack shown in FIG. FIG. 8 is a vertical sectional view of the battery pack shown in FIG. 7.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery 2 ... Inner case 3 ... Inner pack 4 ... Exterior case 5 ... Shock absorption gap 6 ... Elastic spring 7 ... Circuit board 8 ... Battery case 8A ... Main body case
8B ... Lid case 9 ... Battery holder 10 ... Deformation gap 11 ... Insertion groove 12 ... Substrate holder 13 ... Lead plate 14 ... Bulkhead 15 ... Storage chamber 16 ... Output terminal 17 ... Storage chamber 18 ... Output lead 19 ... Perimeter wall 20 ... Cap 21 ... End face plate 22 ... Side wall 23 ... Tube part 24 ... Slit 25 ... Connecting arm 26 ... Contact convex part

Claims (1)

A battery pack comprising an inner pack (3) for storing a plurality of batteries (1) in a fixed position of an inner case (2), and an outer case (4) for storing the inner pack (3),
A shock absorbing gap (5) is provided between the inner pack (3) and the outer case (4), and one end of the inner pack (3) or the outer case (4) is positioned in the shock absorbing gap (5). A hard plastic or metal elastic spring (6) that is elastically deformed by the impact of the battery pack and absorbs the impact energy, and the inner pack (3) is connected to the inner case (2). comprising a cap (20) formed by deposited, to the cap (20), Rupa click cell elastic spring (6) disposed in the shock-absorbing gaps (5) are provided in the integral structure.

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