JP2008123950A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack in which damage of a film body is prevented and which is excellent in appearance quality and safety even in the case the outer case composed of the film body is used. <P>SOLUTION: The battery pack 1 has a unit cell 10 and a protection circuit board 41, and a constitution that an exterior tube 32 covers surroundings of these. Moreover, in the battery pack 1, an insulating plate 26 is interposed between the protection circuit board 41 and the exterior tube 32, and at the end of the protection circuit board 41 in the direction along the outer peripheral face of the unit cell 10, a gap exists between the insulating plate 26 and the outer peripheral face of the unit cell 10. Then, the battery pack 1 has a constitution that a tongue part 26b of the insulating plate 26 extended and installed toward outside than the end of the protection circuit board 41 in the direction along the outer peripheral face of the unit cell 10 is inclined to the outer peripheral face of the unit cell 10. The exterior tube 32 in this region is covered on the tongue part 26b. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a battery pack, and more particularly to a battery pack in which an element or a circuit board is placed on the outer surface of a unit cell and the outer periphery is covered with a film material in this state.

  With the spread of mobile devices such as mobile phones, secondary batteries have become widespread. Among secondary batteries, high-power lithium-ion batteries are remarkably widespread. Lithium ion batteries have advantages such as high energy density, but they need to be protected against overcharge / overdischarge and large currents. For this reason, protection circuits are used in combination. Lithium ion batteries combined with protective circuits may take a form that is housed in a resin case in this state, but the outer periphery is covered with a heat-shrinkable tube from the viewpoint of improving space efficiency and reducing costs. (For example, Patent Documents 1 and 2).

A conventional configuration of a battery pack including a lithium ion battery and having an outer periphery covered with a heat shrinkable tube will be described with reference to FIGS. 4 and 5.
As shown in FIG. 4, the battery pack has a cylindrical lithium ion battery 110 on which a protective circuit board (not shown in FIG. 4) is placed, and in that state, the outer periphery is covered with a heat-shrinkable tube 132. Have Lead wires 151 and 152 connected to the protection circuit board extend from the opening portion of the heat shrinkable tube 132, and an external connection terminal 153 is connected to the tip thereof.

  As shown in FIG. 5A, the conventional battery pack has a protection circuit board 141 on which electronic components 1411 and 1412 are mounted on the outer surface of the lithium ion battery 110. A lead plate 143 is connected to the protection circuit board 141, and the lead plate 143 is bent along the outer periphery of the lithium ion battery 110 and connected to one pole on the end face of the lithium ion battery 110.

As shown in FIG. 5A, a part of the surface of the lithium ion battery 110 is covered with an interior tube 131. An insulating plate 126 is placed on the protection circuit board 141, and the outer periphery including the lithium ion battery 110 and the protection circuit board 141 is collectively covered with the heat shrinkable tube 132 in this state.
A PP tape 162 is provided between the insulating plate 126 and the outer tube 132 for temporarily fixing the insulating plate 126 and the circuit board 141 to the lithium ion battery 110 before the outer tube 132 is thermally contracted. Further, an insulating plate 123 is inserted between the outer tube 132 and the lead plate 143 at the end surface portion of the lithium ion battery 110 so that the lead plate 143 is not exposed to the outside. .

As shown in FIG. 5B, the insulating plate 126 is made of, for example, strip-shaped paper and covers the protection circuit board 141 on which the electronic components 1411 and 1412 are mounted.
Japanese Patent Laid-Open No. 08-45489 Japanese Patent Laid-Open No. 09-73887

  However, in the above-described conventional battery pack, the edge portion of the insulating plate 126 has a step between the outer surface of the lithium ion battery 110 (C portion in FIG. 5A). The portion that hits the edge portion of the plate 126 is locally pulled, so that the portion that hits the end portion of the insulating plate 126 (C portion in FIG. 5A) and the following portion (D portion in FIG. 5A) Is easily damaged. Moreover, the edge part (E part of FIG.5 (b)) of the insulating board 126 may remain the burr | flash at the time of cutting out the insulating board 126, and this also causes the exterior tube 132 to be damaged easily.

  Further, when the battery pack is used, the lithium ion battery 110 generates heat, but since the outer tube 132 is in contact with the outer surface of the lithium ion battery 110 via the lead plate 143 or the like, the heat is transmitted, It is also conceivable that a force that causes secondary contraction of the portion (D portion in FIG. 5A) following the edge portion works. Even for such a cause, in the conventional battery pack, the outer tube 132 is easily damaged.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a battery pack having high appearance quality and safety, in which damage to the film body is prevented even when the film body is packaged. To do.

  In order to achieve the above object, in a battery pack according to the present invention, a unit cell and an electronic element placed on the outer surface of the unit cell or a circuit board on which the electronic element is mounted (hereinafter referred to as “circuit board or the like”). And a film body in which the unit cell and the circuit board are stuck to each other in close contact with each other. And in the battery pack according to the present invention, an insulating plate is inserted between the circuit board and the film body, in the region outside the end of the circuit board and the like in the direction along the outer surface of the unit cell, An inclined structure that is inclined from the position of the insulating plate having a gap with the outer surface of the unit cell to reach the outer surface of the unit cell is provided, and the film body in the region is deposited on the inclined structure. It is characterized by being.

  As described above, in the battery pack according to the present invention, since the inclined structure is provided in the region outside the end of the circuit board or the like in the direction along the outer surface of the unit cell, the unit cell in the insulating plate is provided. Even in a position where there is a gap with the outer surface, no local stress is applied to the film body. Therefore, in the battery pack according to the present invention, breakage of the film body at the time of manufacture or use can be effectively suppressed.

In the battery pack according to the present invention, a space can be provided between the film body and the outer surface of the unit cell due to the installation of the inclined structure, and the heat of the unit cell generated during charging or the like is generated by this space. Direct transmission to the film body can be prevented. For this reason, in the battery pack according to the present invention, damage to the film body due to secondary shrinkage can be effectively suppressed.
Furthermore, since the battery pack according to the present invention includes a circuit board and the like, this function ensures safety during charging and discharging of the unit cell, and the periphery of the unit cell and the circuit board is attached with a film body. Since this is an exterior, it is advantageous from the viewpoint of space efficiency.

As described above, in the battery pack according to the present invention, the film body can be surely prevented from being damaged while ensuring high safety and space efficiency, and the circuit board and the like, and the terminals of the unit cell are exposed to the outside. Therefore, it has high safety and appearance quality.
In the battery pack according to the present invention, the following variations can be adopted.

  In the battery pack according to the present invention, the insulating plate has a configuration in which a tongue extending from the end of the circuit board or the like in the direction along the outer surface of the unit cell to the outer region is formed, and the tongue is inclined. A variation of a structure can be adopted. Although the inclined structure can be separated from the insulating plate, when it is configured as a part of the insulating plate, it is possible to reduce the number of parts at the time of manufacturing and to reduce the man-hour at the time of manufacturing. Will contribute.

  In addition, when adopting a configuration in which the tongue portion formed as a part of the insulating plate corresponds to the inclined structure as described above, a perforation process is applied to a portion that becomes the extension starting point of the tongue portion. By tilting the tongue with the perforated portion as the fold line, the inclined structure can be obtained. In this case, the perforation is easy to bend, and it is excellent from the viewpoint of securing the dimensional accuracy. The perforation provided on the insulating plate may be open to the outer periphery of the insulating plate, but the tongue (inclined structure) may be removed due to breakage of the perforation during processing. In order to prevent this, it is desirable to adopt a configuration that is closed to the outer periphery.

Moreover, in the battery pack according to the present invention, it is possible to adopt a configuration in which the end portion of the inclined structure contacts the outer surface of the unit cell at its end edge. When this configuration is adopted, local tension in the film body can be most effectively suppressed, so that damage to the film body can be effectively prevented.
In the battery pack according to the present invention, a configuration in which each corner portion on the main surface of the inclined structure is R (square circle) processed may be employed. Thereby, the local stress to the film body in each corner portion of the inclined structure can be relaxed.

  Here, in the battery pack according to the present invention, a heat-shrinkable tube (heat-shrinkable tube) can be adopted as the film body constituting the exterior. By adopting such a material, the battery pack according to the present invention can achieve higher space efficiency and lower cost than the case where a resin case or the like is used as the exterior, and is easy to manufacture. Can also be secured.

  In the battery pack according to the present invention, it is of course possible to adopt a rectangular battery or a flat rectangular battery as a unit cell, but the above effect is particularly effective when a unit cell having a cylindrical appearance is employed. It will be remarkable. Here, when a cylindrical battery is employed as the unit cell, a configuration in which the tongue portion of the insulating plate is directed in the axial direction of the unit cell can be employed. Thereby, the battery pack according to the present invention can cover the film body with a gentle inclination.

  Further, in the battery pack according to the present invention, the type of the unit cell is not particularly limited. Particularly, when a lithium ion battery is adopted as the unit cell, it is excellent from the viewpoint of high energy efficiency. By adopting the above configuration, it is possible to ensure high safety.

Hereinafter, the best mode for carrying out the present invention will be described with reference to an example. The embodiment used in the following description is an example used to explain the configuration and effects of the present invention in an easy-to-understand manner, and the present invention is not limited to the following form except for its essential features. It is not something to receive.
1. Overall Configuration of Pack Battery 1 The overall configuration of the pack battery 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is an exploded perspective view schematically showing the overall configuration of the battery pack 1.

As shown in FIG. 1, the battery pack 1 includes a cylindrical lithium ion battery 10 as a unit cell. In the lithium ion battery 10, a ring-shaped insulating ring 21 is attached to one end face 10 a, and the outer periphery is covered with the interior tube 31 in this state. The internal tube 31 is a heat-shrinkable tube.
Next, the protection circuit unit 40 is placed on the outer peripheral surface 10 c of the lithium ion battery 10 covered with the interior tube 31 with the insulating plate 24 interposed therebetween. In this protection circuit section 40, lead plates 42 and 43 are connected to a protection circuit board 41, and lead wires 51 and 52 connected to a connector 53 are connected to the protection circuit board 41. An insulating plate 25 is interposed between the lead plate 42 and the lead wires 51 and 52.

  The lead plates 42 and 43 are each bent into an L shape, and are connected to the bipolar terminals (terminals 10a and 10b) of the lithium ion battery 10 at their tips. On the protection circuit board 41 placed on the outer peripheral surface 10c of the lithium ion battery 10, an insulating plate 26 is coated, and each end face 10a of the lithium ion battery 10 to which the lead plates 42 and 43 are connected, 10b is covered with disc-shaped insulating plates 22 and 23, respectively.

The insulating plate 26 is made of, for example, paper having a thickness of 0.35 [mm], and includes a main body portion 26a that is bent into a letter C on both sides and a tongue portion 26b that extends from one end of the body portion 26a. Yes. The insulating plate 26 is temporarily fixed to the inner tube 31 that covers the outer surface 10 c of the lithium ion battery 10 with PP tapes 61 and 62.
The battery pack 1 is configured by covering the outer side with an outer tube 32 in a state where the protective circuit unit 40 is placed on the outer peripheral surface 10 c of the lithium ion battery 10. Note that a label 70 is attached to the outer tube 32, and lead wires 51 and 52 are extended from the opening.

2. Configuration of Insulating Plate 26 The configuration of the insulating plate 26 will be described with reference to FIGS.
As shown in FIG. 2A, in the battery pack 1 according to the present embodiment, as described above, the insulating plate 26 includes the main body portion 26a and the tongue portion 26b. And each corner of the insulating board 26 including the tongue part 26b is R-processed.

As shown in FIGS. 2B and 3, the tongue 26 b of the insulating plate 26 is inclined toward the outer peripheral surface 10 c (see FIG. 1) of the lithium ion battery 10 as the distance from the main body 26 a increases. It has been bent. In addition, in the insulating plate 26, the main body 26a is also bent into a channel shape.
As shown in FIG. 2 (a), perforations 26c are formed at the folding line portions of the insulating plate 26 during each folding process. By forming the perforations 26c, even if a thick material is used as the constituent material of the insulating plate 26, it is possible to easily and accurately perform the bending process.

As shown in FIG. 2 (a), in the insulating plate 26 according to the present embodiment, the perforations 26c are formed as closed with respect to the outer periphery thereof. This is because the perforations 26c are formed with respect to the outer periphery. This is to prevent damage at the time of processing or the like and prevent the tongue 26b from being removed as compared with the case of forming it open.
3. Advantage of Pack Battery 1 The advantage of the battery pack 1 according to the present embodiment will be described with reference to FIG. 3 and FIGS. 5 (a) and 5 (b).

  First, as shown in FIG. 5A, in the conventional battery pack, since the flat insulating plate 126 is used, the outer tube 132 is locally pulled at each outer peripheral portion thereof. Further, as described above, burrs may occur at the end E (FIG. 5B) of the insulating plate 126 during the production thereof, and this also causes the outer tube 132 at the C portion in FIG. Is easily damaged. Further, in the region on the right side of FIG. 5A from the region where the protection circuit board 141 is placed, the outer tube 132 is in close contact with the outer peripheral surface of the lithium ion battery 110 with the lead plate 143 and the like sandwiched therebetween. Therefore, the heat generated from the lithium ion battery 110 during driving is directly transmitted to the outer tube 132. For this reason, the conventional battery pack also has a problem of secondary contraction of the outer tube 132.

  On the other hand, as shown in FIG. 3, in the battery pack 1 according to the present embodiment, the tongue portion 26b of the insulating plate 26 is inclined (A portion in FIG. 3), and the end portion is lithium ion. The battery 10 is in contact at the edge of the outer peripheral surface 10c (see FIG. 1). The outer tube 32 is attached to the tongue 26b of the insulating plate 26 in the region on the right side in FIG. 3 with respect to the region where the protection circuit board 41 is placed. For this reason, in the battery pack 1 according to the present embodiment, the boundary portion (see FIG. 5A) between the body portion 26a (see FIGS. 2A and 2B) and the tongue portion 26b in the insulating plate 26. The exterior tube 32 does not receive a local pulling force at a portion corresponding to the portion C) and is not easily damaged.

  Further, in the battery pack 1 according to the present embodiment, the tongue portion 26b of the insulating plate 26 is configured to be in contact with the end portion of the lithium ion battery 10 while being inclined with respect to the outer peripheral surface 10c. A space is provided between the outer tube 32 and the outer peripheral surface 10c of the lithium ion battery 10 in the portion 26b. For this reason, in the battery pack 1, heat generated from the lithium ion battery 10 at the time of charging / discharging or the like is not directly transmitted to the outer tube 32, and the problem of secondary contraction of the outer tube 32 is unlikely to occur.

Moreover, in the battery pack 1, since the edge part of the tongue part 26b of the insulating plate 26 is comprised so that it may contact with the outer peripheral surface 10c in the lithium ion battery 10 in the edge, the inclination of the tongue part 26b is carried out. It is gentle as much as possible, and is excellent from the viewpoint of preventing the outer tube 32 from being damaged.
In addition, since the battery pack 1 includes the protection circuit unit 40, it is excellent from the viewpoint of ensuring the safety of the lithium ion battery 10 during charging and discharging, and the exterior is configured with a heat-shrinkable tube, so that high space efficiency and cost reduction are achieved. Excellent from the viewpoint.

4). Variations As described above, the present embodiment is adopted as an example in order to easily understand the structural features of the present invention and the effects obtained therefrom. The configuration other than the characteristic features is not limited to the above embodiment. That is, in the battery pack according to the present invention, in the region outside the edge of the circuit board or the like in the direction along the outer surface of the unit cell, the battery pack is inclined from the position of the insulating plate having a gap with the outer surface of the unit cell. An inclined structure that reaches the outer surface of the unit cell is provided, and an essential feature is that the film body in the region is deposited on the inclined structure, and other configurations are appropriately changed. Is possible. For example, the following variations can be employed.

In the battery pack 1 according to the above-described embodiment, the lithium ion battery 10 is applied as a unit cell. However, an alkaline battery such as a nickel-cadmium battery or a nickel-hydrogen battery can also be used. The battery pack 1 according to the embodiment is configured to include one lithium ion battery 10, but may be configured to include two or more unit cells.
In the battery pack 1 according to the above-described embodiment, a cylindrical battery is used as the unit cell. However, a square battery, a flat battery, or the like can be used. Also in this case, the above advantages can be obtained.

Further, in the battery pack 1 according to the above-described embodiment, the exterior is configured by the heat shrinkable tube, but the film body is not necessarily a heat shrinkable tube.
In the battery pack 1 according to the above embodiment, the tongue portion 26b, which is a part of the insulating plate 26, is provided as the inclined structure. However, the inclined structure is a separate member from the insulating plate 26. You can also

  Furthermore, as shown in FIG. 2B, in the above embodiment, the body 26a of the insulating plate 26 is channel-shaped and the tongue 26b is inclined with respect to the axial direction of the lithium ion battery 10. However, even if only one of the configuration in which the main body portion 26a is channel-shaped and the configuration having the tongue portion 26b is adopted, the effect of preventing damage to the outer tube can be obtained as compared with the conventional battery pack. Is superior to.

  The present invention is effective in realizing higher safety and higher appearance quality in a battery pack used as a power source for portable equipment such as a handy terminal.

It is an expansion | deployment perspective view which shows the structure of the battery pack 1 which concerns on embodiment of this invention. (A) is a top view which shows the insulating board 26 distribute | arranged on the protection circuit board 41, (b) is the side view. 2 is a cross-sectional view showing a partial structure of a battery pack 1. FIG. It is a perspective view which shows the external appearance of the conventional battery pack. (A) is sectional drawing which shows the partial structure of the conventional battery pack, (b) is an expansion | deployment perspective view which shows the arrangement | positioning relationship between the protective circuit board 141, the lead plates 142 and 143, and the insulating board 126. FIG.

Explanation of symbols

1. Pack battery 10. Unit cell 21. Insulating ring 22-26. Insulating plate 31. Interior tube 32. Outer tube 40. Protection circuit section 41. Protection circuit board 42, 43. Lead plate 51, 52. Lead wire 53. Connector 61, 62. PP tape 70. Labels 411, 412. element

Claims (8)

A unit cell, an electronic element placed on the outer surface of the unit cell or a circuit board on which the electronic element is mounted, and the unit cell and the electronic element or the circuit board are stretched around the unit in close contact with each other. A battery pack having a film body,
An insulating plate is interposed between the electronic element or the circuit board and the film body,
In the region outside the edge of the electronic element or the circuit board in the direction along the outer surface of the unit cell, the element is inclined from the position of the insulating plate having a gap with the outer surface of the unit cell. The battery pack is characterized in that an inclined structure reaching the outer surface of the battery is provided, and the film body in the region is deposited on the inclined structure. The insulating plate is formed with a tongue extending from the end of the electronic element or the circuit board in a direction along the outer surface of the unit cell to the outer region,
The battery pack according to claim 1, wherein the inclined structure corresponds to a tongue portion of the insulating plate. The insulating plate is perforated on a portion that becomes an extension starting point of the tongue,
The battery pack according to claim 2, wherein the tongue portion is bent with the perforated portion as a fold line. 4. The battery pack according to claim 1, wherein an end of the inclined structure is in contact with the outer surface of the unit cell at an edge of the outer surface. 5. The battery pack according to any one of claims 1 to 4, wherein each corner portion of the main surface of the inclined structure is subjected to R processing. The battery pack according to claim 1, wherein the film body is a heat-shrinkable tube. The unit cell has a cylindrical external shape,
The battery pack according to any one of claims 1 to 6, wherein the inclined structure has a configuration inclined toward an axial direction of the unit cell. A battery pack according to any one of claims 1 to 7, wherein a lithium ion battery is applied as the unit cell.

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