JP2005259574A - Battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack in which bending of the lead plate in accordance with the design can be obtained. <P>SOLUTION: In the battery pack in which the battery and the lead plate 20 having a plurality of folded points are housed in the outer case, inflected plate type projections 40, 40 are formed from the end fringe of the folded points of the lead plate 20. One of the tip end parts of the lead plate 20 is folded into a U-shape, and the plate type projections 40 are formed between the folded points of the parts folded into the U-shape, folded toward the aperture direction of the U-shape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lead plate bent at a plurality of bent portions and a battery pack in which a battery to which the lead plate is connected is accommodated in a case.

  As a driving power source for small electronic devices or portable electronic devices, a battery pack in which a power generation element including a positive electrode and a negative electrode is housed in a battery case, and a lead plate and a protective circuit board are housed in a synthetic resin outer case. Used (see, for example, Patent Document 1).

  FIG. 1 is an exploded perspective view of the battery pack. In FIG. 1, 10 is a battery, 32 and 34 are half case cases, 30 is a double-sided tape, 12 is a negative terminal of the battery 10, 22 is a negative lead plate, 28 is a PTC (Positive Temperature Coefficient) element, and 16 is an insulating sheet. , 20 is a positive lead plate, and 14 is a protective circuit board.

  FIG. 6A is an enlarged perspective view of one end portion of a conventional positive electrode lead plate 20. One end portion of the positive electrode lead plate 20 is formed in an L shape, and a protruding plate 20a protruding in a right angle direction from the one end portion is close to the base so that the entire one end portion is U-shaped. It is bent at two bends. FIG. 6B is an enlarged perspective view of one end portion of the positive electrode lead plate 20 in which the protruding plate 20a is bent at a bent portion closer to the root. The protruding plate 20a is formed with recesses 2 and 2 at opposite edges from the base to the tip, and is bent at the recesses 2 and 2 as shown in FIG.

  In many cases, as shown in FIG. 6B, for example, the positive electrode lead plate 20 is supplied in a state in which the protruding plate 20a is bent at a bent portion closer to the base, for example, the protection circuit board 14 and the protruding plate 20a. Are fixed electrically and mechanically, the concave portions 2 and 2 of the protruding plate 20a are bent.

Further, the negative electrode lead plate 22 is formed in an L shape at one end portion similarly to the positive electrode lead plate 20, and the protruding plate 22 a of the negative electrode lead plate 22 is similar to the protruding plate 20 a of the positive electrode lead plate 20. The one end portion is bent at two bent portions so as to be U-shaped. The negative electrode lead plate 22 is also bent at portions other than the one end portion. Similarly to the positive electrode lead plate 20, the negative electrode lead plate 22 is also supplied in a state where the protruding plate 22a is bent at a bent portion closer to the root. For example, the protection circuit board 14 and the protruding plate 22a are electrically and mechanically connected. After being fixed, the recesses 2 and 2 of the protruding plate 22a are bent.
JP 2003-168409 A

  However, there is a problem that when the concave portions 2 and 2 are bent, the bending cannot be stably performed. FIGS. 7A, 7B, and 7C are cross-sectional views taken along line XX of one end portion of the positive electrode lead plate 20 shown in FIG. For example, as shown in FIG. 7 (a), the lead plate shape between two bent portions is not flat but curved, or the bent portions are displaced as shown in FIG. 7 (b). There is a problem that a bent shape as designed cannot be obtained. Further, as shown in FIG. 7C, there is a problem that the recesses 2 and 2 protrude and bend at an acute angle, and the lead plate is broken starting from the bent portion at the acute angle.

  The present invention has been made in view of such circumstances, and provides a battery pack that can be bent as designed by forming a bent plate-like protrusion from the edge of the bent portion of the lead plate. The purpose is to do.

  Another object of the present invention is to provide a battery pack in which the lead plate can be miniaturized by bending the plate-shaped protrusion in the opening direction of the U-shaped portion.

  A battery pack according to a first aspect of the present invention is a battery pack in which a lead plate bent at a plurality of bent portions and a battery to which the lead plate is connected are housed in a case, and is bent from an edge of the bent portion of the lead plate. A plate-like protrusion is formed.

  A battery pack according to a second invention is the battery pack according to the first invention, wherein the bent portion where the plate-like protrusion is formed is bent in a U-shape, and the plate-like protrusion is bent in the opening direction of the U-shaped portion. It is characterized by.

  In the first invention, the portion of the lead plate where the plate-like protrusion is formed is stronger than the portion where the plate-like protrusion is not formed. Therefore, when bending the bent portion sandwiching the plate-like protrusion, It is not bent at the portion where the projection is formed, but is bent near the boundary between the portion where the plate-like projection is formed and the portion where it is not formed.

  In the second invention, when the plate-like protrusion is bent in the direction opposite to the opening direction of the U-shaped portion, the bending direction of the lead plate of the U-shaped portion and the bending direction of the plate-like protrusion are opposite directions, The plate-shaped protrusion protrudes outside the U-shaped part. On the other hand, when the plate-like protrusion is bent in the opening direction of the U-shaped part, the bending direction of the lead plate in the U-shaped part is the same as the bending direction of the plate-like protrusion, and the plate-like protrusion is the same as the U-shaped part. Do not protrude outwards.

  According to the first invention, it is possible to obtain bending as designed. Further, the lead plates can be prevented from overlapping by forming the plate-like projections.

  According to the second invention, it is possible to prevent the plate-like projections from protruding to the outside, and to reduce the size of the lead plate.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
FIG. 1 is an exploded perspective view of the battery pack. The battery pack is obtained by storing the battery 10 in a rectangular parallelepiped outer case (outer case half bodies 32 and 34) made of synthetic resin. The battery 10 is a secondary battery such as a nonaqueous electrolyte secondary battery in which a power generation element in which a positive electrode and a negative electrode are wound via a separator is housed in an aluminum battery case, and a negative electrode terminal 12 is provided on one side of the battery case. Have. Note that the battery case and the negative electrode terminal 12 are insulated, and the entire battery case excluding the portion where the negative electrode terminal 12 is provided is a positive electrode terminal.

  A protective circuit board 14 is disposed on a side surface of the battery case that faces the one side surface. The protection circuit board 14 is a circuit board provided with a protection circuit for preventing overcharge or overdischarge of the battery 10. A circuit element (not shown) is mounted on the surface of the protective circuit board 14 facing the battery 10, and positive and negative output terminals 14 a are provided on the opposite surface. In addition, a through hole 32 a that matches the output terminal 14 a of the protection circuit board 14 is formed on one side surface of the outer case half 32.

  The protective circuit board 14 is connected to the battery case that also serves as the positive terminal of the battery 10 through the positive lead plate 20 and is connected to the negative terminal 12 of the battery 10 through the negative lead plate 22 and the PTC element 28. Is done. The PTC element 28 is a protective element that cuts off the circuit by becoming high resistance when the temperature of the battery 10 is abnormally increased. The PTC element 28 can be attached to an arbitrary position of the negative electrode lead plate 22.

  Although the negative electrode lead plate 22 is provided along the side surface of the battery 10, the battery case also serves as a positive electrode terminal. Therefore, a short circuit is prevented between the negative electrode lead plate 22 and the PTC element 28 and the side surface of the battery case. An insulating sheet 16 is provided. The battery 10 to which the protection circuit board 14 is connected is accommodated in the outer case halves 32 and 34 with the directions of the protection circuit board 14 and the through holes 32a aligned, and the outer case halves 32 and 34 are bonded, thermally welded, or super-bonded. It is fixed by sonic welding.

  FIG. 2A is an enlarged perspective view of one end portion of the positive electrode lead plate 20 of the present invention. One end portion of the positive electrode lead plate 20 is formed in an L shape, and a protruding plate 20a protruding in a right angle direction from the one end portion is close to the base so that the entire one end portion is U-shaped. It is bent at two bends. A bent plate-like protrusion 40 is formed from the edge of the bent portion of the U-shaped portion of the positive electrode lead plate 20. In the example of FIG. 2A, the protruding plate 20a is formed with bent plate-like protrusions 40, 40 at the opposite end edges between the bent portions. Further, in the example of FIG. 2A, the plate-like protrusions 40, 40 are bent substantially at right angles to the opening direction of the U-shaped portion.

  FIG. 2B is a diagram in which the protruding plate 20a is bent at a bent portion closer to the base. In many cases, as shown in FIG. 2B, for example, the positive electrode lead plate 20 is supplied in a state where the protruding plate 20a is bent at a bent portion closer to the base, for example, the protection circuit board 14 and the protruding plate 20a. Are fixed electrically and mechanically, the protruding plate 20a is bent at the peripheral portion of the plate-like protrusion 40 as shown in FIG.

  The positive electrode lead plate 20 is a conductive plate made of nickel, for example, and has a width a = 4 mm and a thickness of 0.1 mm, for example. The protruding plate 20a has, for example, a width b = 4 mm and a length c = 6 mm. The plate-like protrusion 40 has, for example, a width d = 1 mm and a length (e + f) = 0.6 mm, and is bent inward at a substantially right angle at a portion 0.2 mm (= e) from the root portion.

  The portion of the protrusion plate 20a where the plate-like protrusion 40 is formed has improved strength, and when the protrusion plate 20a is bent, the portion where the plate-like protrusion 40 is formed is not bent and the plate-like protrusion 40 is formed. Bends at the boundary between the part and the part that is not formed. Therefore, a bent shape as designed can be obtained.

  In the above-described embodiment, the plate-like protrusion 40 is bent in the opening direction of the U-shaped portion, but can be bent in the opposite direction. 3A and 3B are enlarged perspective views of one end portion of the positive electrode lead plate 20 of the present invention. FIG. 3A is a view after bending, and FIG. 3B is a view before bending. Even when the plate-like protrusion 40 is bent in the opposite direction, a bent shape as designed can be obtained in the same manner as when the plate-like protrusion 40 is bent in the opening direction, but when the plate-like protrusion 40 is bent in the opposite direction, Since the plate-like protrusion 40 protrudes toward the outer surface of the letter-shaped part, it is preferable that the plate-like protrusion 40 is bent in the opening direction of the U-shaped part to eliminate the protrusion and reduce the size.

  Further, in each of the above-described embodiments, it is possible to form the recess 42 near the boundary between the portion where the plate-like protrusion 40 of the protruding plate 20a is formed and the portion where it is not formed. 4 (a) and 4 (b) and FIGS. 5 (a) and 5 (b) are enlarged perspective views of one end portion of the positive electrode lead plate 20 of the present invention. FIG. 4 (a) and FIG. ) After bending, and FIG. 4B and FIG. 5B are views before bending. 4A and 4B, the plate-like protrusion 40 is bent in the opening direction of the U-shaped portion, and in FIGS. 5A and 5B, the plate-like protrusion 40 is opposite to the opening direction. It is bent in the direction. The recess 42 is formed to have, for example, a width g = 0.5 mm at an edge portion near the plate-like protrusion 40. By forming the recess 42 at the edge near the boundary between the portion where the plate-like protrusion 40 of the protruding plate 20a is formed and the portion where it is not formed, the protruding plate 20a can be easily bent.

  In each of the embodiments described above, the positive electrode lead plate 20 has the protruding plate 20a closer to the root as shown in FIGS. 2 (b), 3 (b), 4 (b), and 5 (b). However, the protruding plate 20a may be supplied in a state where it is not bent at the bent portion closer to the root. In this case, one end portion of the positive electrode lead plate 20 is supplied in a flat shape, and the protruding plate 20a is bent even at the bent portion closer to the root, but when the protruding plate 20a is bent, as described above, Since the portion where the plate-like protrusion 40 is formed is not bent and is bent at the boundary between the portion where the plate-like protrusion 40 is formed and the portion where it is not formed, a bent shape as designed can be obtained. In this case, since the positive electrode lead plate 20 is supplied in a state where the two bent portions sandwiching the plate-like protrusion 40 are not bent, the bending direction of the protruding plate 20a (the upper side direction or the lower side direction in the figure) is set. It becomes possible to select.

  In each of the above-described embodiments, the positive electrode lead plate 20 has been described as an example. However, the plate-like protrusion 20 a of the present invention can be formed on the negative electrode lead plate 22. In the example shown in FIG. 1, the tip portions of the positive electrode lead plate 20 and the negative electrode lead plate 22 on the side of the protective circuit board 14 have the same shape, and the negative electrode lead plate 22 also has a protruding plate 22a. The protrusion 40 can be formed on the protruding plate 22 a of the negative electrode lead plate 22. Further, the plate-like protrusion 40 can be formed from an edge of an arbitrary bent portion of the lead plates 20 and 22, for example, formed at an edge between arbitrary bent portions of the lead plates 20 and 22.

It is a disassembled perspective view of a battery pack. It is an expansion perspective view of one tip part of the positive electrode lead plate of the present invention. It is an expansion perspective view of one tip part of the positive electrode lead plate of the present invention. It is an expansion perspective view of one tip part of the positive electrode lead plate of the present invention. It is an expansion perspective view of one tip part of the positive electrode lead plate of the present invention. It is an expansion perspective view of the front-end | tip part of the conventional positive electrode lead plate. It is XX sectional view taken on the line of the front-end | tip part of the conventional positive electrode lead plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Battery 12 Negative electrode terminal 14 Protection circuit board 16 Insulation sheet 20 Positive electrode lead board 20a Positive electrode lead board protrusion board 22 Negative electrode lead board 22a Negative electrode lead board protrusion board 28 PTC element 30 Double-sided tape 32, 34 Exterior case half body 40 Plate shape Projection 42 Recess

Claims (2)

In a battery pack in which a lead plate bent at a plurality of bent portions and a battery to which the lead plate is connected are accommodated in a case,
A battery pack, wherein a bent plate-like protrusion is formed from an edge of the bent portion of the lead plate. 2. The battery pack according to claim 1, wherein the bent portion where the plate-like protrusion is formed is bent in a U-shape, and the plate-like protrusion is bent in the opening direction of the U-shaped portion. .

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