JP2011108422A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack equipped with an outside frame which improves the protection of a corner of a unit battery while having a simple structure. <P>SOLUTION: The battery pack with an exterior part 23 including a protection circuit 12 attached to an end of the unit battery 2 is equipped with an outside frame 15 covering the outer periphery of an assembly body 40 for the unit battery 2 and the exterior part 23. In this case, the outside frame 15 is formed in a U shape by a horizontal frame 30 covering the exterior part 23 and a pair of vertical frames 31 covering a pair of sides 4 for the unit battery 2. When the end at a side opposite to the end to which the exterior part 23 is attached in the unit battery 2 is a bottom 18, the vertical frames 31 are fitted to the sides 4 of the unit battery 2 and the bottom 18 of the unit battery 2 at a corner 21 of the unit battery 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a battery pack provided with an external frame attached to the outer periphery of a unit cell.

  With the recent thinning and miniaturization of battery packs, battery packs having an exterior part in which a protection circuit and a protection element are integrated at an end of a unit cell are becoming mainstream.

  In such a battery pack, when preventing damage / deformation due to a drop impact, it is necessary to protect the exterior part of the upper part of the unit cell, and to protect the corner part where the unit cell is likely to be damaged / deformed. Become.

  In order to protect the battery pack as described above, it is effective to cover the battery pack with another member such as a protective cover. Patent Document 1 below discloses a battery pack in which an outer frame formed by integrally forming a pair of side frames, a terminal frame, and a bottom frame is mounted on the outer periphery of a unit cell.

JP 2007-73203 A

  However, the exterior frame described in Patent Document 1 has a shape restriction in order to facilitate mold release. For example, the corners of the outer frame are only located at the positions corresponding to the corners of the unit cell, and are not fitted in accordance with the shape of the corners of the unit cell.

  That is, the exterior frame described in Patent Document 1 can cover the entire outer periphery of the four sides of the unit cell with a single component, but is not necessarily advantageous in terms of protection of the unit cell.

  The present invention solves the conventional problems as described above, and an object of the present invention is to provide a battery pack having an external frame that can improve the protection of the corners of the unit cell while having a simple structure. And

  In order to achieve the above object, a battery pack of the present invention is a battery pack in which an exterior part including a protection circuit is attached to an end part of a unit cell, and the assembly of the unit cell and the exterior part is provided. An outer frame that covers an outer periphery, and the outer frame is formed in a U shape with a horizontal frame that covers the exterior portion and a pair of vertical frames that cover a pair of side portions of the unit cell, Assuming that the end of the unit cell opposite to the end to which the exterior part is attached is the bottom, the vertical frame is at the corner of the unit cell, at the side of the unit cell and the bottom of the unit cell. It is characterized by being fitted to.

  ADVANTAGE OF THE INVENTION According to this invention, the battery pack provided with the external frame which can improve the protection of the corner | angular part of a unit cell can be provided, although it is a simple structure.

1 is an exploded perspective view of a battery pack 1 according to an embodiment of the present invention. The perspective view which shows the state before affixing the insulating tape 9 on the edge part 8 of the upper side of the unit cell 2 in one embodiment of this invention. The perspective view which shows the state before attaching the internal frame 10 to the unit cell 2 in one embodiment of this invention. The perspective view which shows the state before attaching the protection circuit 12 to the internal frame 10 in one embodiment of this invention. 1 is a perspective view showing a state in which a protection circuit 12 is attached to an internal frame 10 in an embodiment of the present invention. The perspective view which shows the state before attaching the external flame | frame 15 to the assembly 40 in one embodiment of this invention. (A) The figure is sectional drawing in the AA line of FIG. 6, (b) The figure is sectional drawing in the BB line of FIG. The enlarged view of the C section of FIG. The perspective view which shows the state in the middle of mounting | wearing the assembly 40 with the external flame | frame 15 in one embodiment of this invention. The perspective view which shows the state which mounted | wore the assembly 40 with the external frame 15 in one embodiment of this invention. The enlarged view of the D section of FIG. 11A is a cross-sectional view taken along line EE in FIG. 11, and FIG. 11B is a cross-sectional view taken along line FF in FIG. The perspective view which shows the completion state of the battery pack which concerns on one embodiment of this invention.

  According to the battery pack of the present invention, the vertical frame of the outer frame is fitted to the side of the unit cell and the bottom of the unit cell at the corner of the unit cell, and the vertical frame wraps around the corner of the unit cell. It will be so attached. This ensures that the vertical frame is securely attached to the corner of the unit cell, prevents the external frame from being detached from the unit cell, and protects the corner of the unit cell that is easily damaged or deformed by a drop impact. Can be improved. Further, the outer frame has a U-shape and a simple structure, so that it can be easily molded and attached to the unit cell.

  In the battery pack of the present invention, the vertical frame has a standing portion at a position corresponding to a corner portion of the unit cell, and the standing portion sandwiches a side portion of the unit cell. And a portion along the bottom of the unit cell.

  Moreover, it is preferable that the said horizontal frame is the groove shape which one end opened, and the said groove-shaped part is mounted | worn with the said exterior part. According to this configuration, the horizontal frame is attached to the exterior part so as to sandwich the exterior part, and the attachment of the horizontal frame to the exterior part is ensured.

  Moreover, it is preferable that the said vertical frame is the groove shape which one end opened, and the said groove-shaped part is mounted | worn with a pair of side part of the said unit cell. According to this configuration, the vertical frame is attached to the side of the unit cell so as to sandwich the side of the unit cell, and the vertical frame is reliably attached to the side of the unit cell.

  Further, the vertical frame and the horizontal frame have a groove shape with one end opened, and the groove-shaped portion is formed by a bottom portion and a pair of standing portions standing from the bottom portion, and the vertical frame It is preferable that a notch is formed at an intersection between the standing portion and the standing portion of the horizontal frame. According to this configuration, it is possible to prevent the external frame from being damaged when the external frame is attached.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view of a battery pack 1 according to an embodiment of the present invention. The unit cell 2 includes a power generation element in a rectangular outer can 3 having a thin thickness made of, for example, aluminum or an aluminum alloy. The unit cell 2 is, for example, a rectangular lithium ion battery, and is used for a mobile phone, a portable AV device, a mobile device, and the like.

  A plate-like negative electrode lead 6 and a positive electrode lead 7 are welded to the unit cell 2. The outer can 3 is charged to a positive electrode potential, and a negative electrode terminal (not shown) is formed on the side portion 4 of the unit cell 2 on the negative electrode lead 6 side. The negative electrode lead 6 is welded to the negative electrode terminal. A positive electrode lead 7 is welded to the side portion 4 opposite to the negative electrode lead 6 side.

  A resin internal frame 10 is attached to the upper end 8 of the unit cell 2 via an insulating tape 9. The internal frame 10 can support the protection element 11 and the protection circuit 12. The protection element 11 and the protection circuit 12 are protection means for preventing overcharge, overcurrent, overdischarge, and the like.

  The terminal 11 a of the protection element 11 is welded to the negative electrode lead 6, and the terminal 11 b of the protection element 11 is welded to the terminal 13 on the back surface side of the protection circuit 12. The positive electrode lead 7 is welded to the terminal 14 on the back surface side of the protection circuit 12.

  After the above-described components are attached to the unit cell 2, the external frame 15 is attached. When the outer frame 15 is mounted, the claw portion 39 of the inner frame 10 is engaged with the hole 38 of the outer frame 15.

  An opening 16 is formed in the external frame 15. On the other hand, the protection circuit 12 includes an output terminal 17 for external connection. In the completed state of the battery pack 1, the output terminal 17 is exposed from the opening 16. As a result, when the battery pack 1 is attached to an external device, the terminal of the external device and the output terminal 17 come into contact with each other, and conduction is achieved.

  A label 22 is attached so as to cover the bottom surface 18, the front surface 19, and the back surface 20 of the unit cell 2 to complete the battery pack 1.

  Hereinafter, the battery pack 1 shown in FIG. 1 will be described in the order of manufacturing steps. FIG. 2 is a perspective view showing a state before the insulating tape 9 is attached to the upper end 8 of the unit cell 2. The insulating tape 9 is bent from this state, and the insulating tape 9 is attached to the end 8 of the battery 2.

  FIG. 3 is a perspective view showing a state before the internal frame 10 is attached to the unit cell 2. The inner frame 10 is attached to one side of the insulating tape 9.

  FIG. 4 is a perspective view showing a state before the protection circuit 12 is attached to the internal frame 10. In the state of FIG. 4, the terminal 11 b (FIG. 1) of the protection element 11 is welded to the protection circuit 12, and the negative electrode lead 6 is welded to the terminal 11 a of the protection element 11. A positive electrode lead 7 is welded to the protection circuit 12.

  FIG. 5 is a perspective view showing a state in which the protection circuit 12 is attached to the inner frame 10. The protection circuit 12 is supported by the inner frame 10. In the state of FIG. 5, the protection element 11 (FIG. 4) is housed in the internal frame 10. The negative electrode lead 6 is bent and welded to a negative electrode terminal (not shown). Similarly, the positive electrode lead 7 is bent and welded to the side portion 4 of the unit cell 2. In the state of FIG. 5, the exterior part 23 composed of the internal frame 10, the protection element 11 and the protection circuit 12 is attached to the end part 8 (FIG. 2) of the unit cell 2 via the insulating tape 9 (FIG. 3). The assembly 40 is completed.

  FIG. 6 is a perspective view showing a state before the external frame 15 is attached to the assembly 40. The external frame 15 is a molded product of polycarbonate resin, for example. The external frame 15 is formed in a U shape by a horizontal frame 30 covering the exterior portion 23 and a pair of vertical frames 31 covering the pair of side portions 4 of the unit cell 2.

  7 shows a cross-sectional view of the outer frame 15, FIG. 7 (a) is a cross-sectional view taken along the line AA in FIG. 6, and FIG. 7 (b) is a cross-sectional view taken along the line BB in FIG. As shown in FIG. 7A, the horizontal frame 30 has a groove shape with one end opened. More specifically, the horizontal frame 30 includes an upper bottom portion 32 and a pair of standing portions 33. The lateral frame 30 is attached to the exterior portion 23 so that the exterior portion 23 (FIG. 6) is sandwiched between the pair of standing portions 33. This ensures that the lateral frame 30 is attached to the exterior portion 23.

  As shown in FIG. 7B, the vertical frame 31 has a groove shape with one end opened, like the horizontal frame 30. More specifically, the vertical frame 31 includes a horizontal bottom portion 34 and a pair of standing portions 35. The vertical frame 31 is attached to the side part 4 of the unit cell 2 such that the side part 4 of the unit cell 2 is sandwiched between the pair of standing parts 35. This ensures that the vertical frame 31 is attached to the side portion 4 of the unit cell 2.

  FIG. 8 shows an enlarged view of a portion C of the vertical frame 31 of FIG. A standing part 36 that connects the pair of standing parts 35 is formed at the end of the vertical frame 31. The standing portion 36 forms a curved surface, and this curved surface is formed in accordance with the curved surface of the bottom portion 18 (FIG. 6) of the unit cell 2. According to this configuration, the upright portion 36 can be mounted so as to wrap around the corner portion 21 (FIG. 6) of the unit cell 2, and the vertical frame 31 is securely mounted on the corner portion 21 of the unit cell 2. Details of this will be described later with reference to FIGS.

  FIG. 9 is a perspective view showing a state in the middle of mounting the external frame 15 to the assembly 40. In this state, in the pair of vertical frames 31, a part of the standing portion 35 sandwiches the side portion 4 of the unit cell 2. 7B, the distance W2 between the horizontal bottom surfaces 34a of the pair of vertical frames 31 is substantially the same as the maximum width W1 of the unit cell 2 of FIG. On the other hand, as shown in FIG. 8, at the end of the vertical frame 31, a standing portion 36 having a height h rises from the horizontal bottom surface 34 a.

  Therefore, the distance W3 (FIG. 6) between the pair of upright portions 36 is smaller by about two heights h than the maximum width W1 of the unit cell 2 of FIG. For this reason, in the state of FIG. 6, the distance between the edge parts of a pair of vertical frame 31 has spread in the horizontal direction (arrow a direction). Due to this spreading, stress is concentrated at the intersection between the standing portion 33 and the standing portion 35. In the present embodiment, the notch 37 is formed to prevent the external frame 15 from being damaged due to stress concentration when the external frame 15 is attached. The notch 37 is desirably formed at the intersection of the standing portion 33 and the standing portion 35 also on the back side of FIG.

  FIG. 10 is a perspective view showing a state where the external frame 15 is attached to the assembly 40 (FIG. 6). FIG. 11 shows an enlarged view of a portion D in FIG. The state of FIG. 10 is a state in which the external frame 15 is further pushed down from the state of FIG. In this state, the claw portion 39 integral with the inner frame 10 is engaged with the opening 38 of the outer frame 15.

  As shown in FIG. 11, the end of the vertical frame 31 is fitted so as to wrap around the corner 21 (FIG. 9) of the unit cell 2. In FIG. 9, the corner portion 21 includes a part of the side part 4 and a part of the bottom part 18 of the unit cell 2. In the state of FIG. 11, the end portion of the vertical frame 31 is fitted to both the side portion 4 and the bottom portion 18 of the unit cell 2. This will be described with reference to FIG.

  12A is a cross-sectional view taken along line EE in FIG. 11, and FIG. 12B is a cross-sectional view taken along line FF in FIG. As shown in FIG. 12A, the standing portion 36 having a height h is fitted to the side portion 4 of the unit cell 2 with the side portion 4 of the unit cell 2 interposed therebetween. In FIG. 12A, although there is no gap between the lateral bottom surface 34a and the side part 4 of the unit cell 2, a gap may be formed.

  In FIG. 12B, the curved surface portion of the inner periphery of the standing portion 36 is fitted along the curved surface portion of the bottom portion 18 of the unit cell 2.

  Therefore, the end portion of the vertical frame 31 is fitted to both the side portion 4 and the bottom portion 18 of the unit cell 2 at the corner portion 21 of the unit cell 2. This configuration is advantageous for fixing the external frame 15 to the unit cell 2 and also for protecting the corner portion 21 of the unit cell 2.

  That is, according to the external frame 15 of the present embodiment, it is possible to prevent detachment from the unit cell 2 while having a simple configuration that does not cover the entire bottom portion 18 of the unit cell 2, and damage / deformation due to a drop impact. It is possible to improve the protection of the corner portion 21 of the unit cell 2 that is prone to occur.

  On the other hand, the outer frame 15 has a U-shape that does not have a portion covering the entire bottom portion 18 of the unit cell 2, so that the outer frame 15 can be easily formed. Further, as shown in FIG. 9, the external frame 15 can be easily attached to the unit cell 2 by expanding the pair of vertical frames 31 in the horizontal direction (arrow a direction) and pressing them downward.

  On the other hand, the shape in which the upright portion 36 having a height h in FIG. 8 is extended to the upright portion 36 of the other vertical frame 31 and the outer frame 15 is configured with four sides is difficult to mold. This makes molding difficult. Moreover, it becomes difficult to attach such a shape to the unit cell 2.

  FIG. 13 is a perspective view showing a completed state of the battery pack 1. In the state of this figure, the label 22 is affixed so that the bottom face 18, the surface 19, and the back surface 20 of the unit cell 2 shown in FIG. 1 may be covered.

  In the present embodiment, the configuration of the exterior portion 23 is an example, and other configurations may be used. For example, the structure which aggregated the positive electrode terminal and the negative electrode terminal on the upper part of the unit cell may be sufficient. Moreover, the structure which is not provided with the protection element may be sufficient.

  As described above, the present invention can provide a battery pack provided with an external frame that can improve the protection of the corners of the unit cell while having a simple structure. It is useful as a battery pack for use in portable AV devices, mobile devices and the like.

DESCRIPTION OF SYMBOLS 1 Battery pack 2 Unit cell 4 Side part of unit cell 8 End part of unit cell 10 Internal frame 11 Protection element 12 Protection circuit 15 External frame 18 Bottom part of unit cell 21 Corner part of unit cell 23 Exterior part 30 Horizontal frame 31 Vertical frame 33, 35, 36 Standing portion 37 Notch 40 Assembly

Claims (5)

A battery pack in which an exterior part including a protection circuit is attached to an end of a unit cell,
An external frame covering the outer periphery of the assembly of the unit cell and the exterior part,
The outer frame is formed in a U shape with a horizontal frame covering the exterior part and a pair of vertical frames covering a pair of side parts of the unit cell,
When the end opposite to the end to which the exterior part is attached is the bottom of the unit cell,
The battery pack, wherein the vertical frame is fitted to a side portion of the unit cell and a bottom portion of the unit cell at a corner of the unit cell.   The vertical frame forms a standing portion at a position corresponding to a corner portion of the unit cell, and the standing unit extends along a portion sandwiching a side portion of the unit cell and a bottom portion of the unit cell. The battery pack according to claim 1, further comprising:   The battery pack according to claim 1, wherein the horizontal frame has a groove shape with one end opened, and the groove-shaped portion is attached to the exterior portion.   4. The battery pack according to claim 1, wherein the vertical frame has a groove shape with one end opened, and the groove-shaped portion is attached to a pair of side portions of the unit cell. 5.   Each of the vertical frame and the horizontal frame has a groove shape with one end opened, and the groove-shaped portion is formed by a bottom portion and a pair of standing portions standing from the bottom portion. The battery pack according to any one of claims 1 to 4, wherein a notch is formed at an intersecting portion between the installation portion and the standing portion of the horizontal frame.

Images