JP2006049047A - Battery pack and method of manufacturing battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack and a method of manufacturing the battery pack wherein welding can be carried out with superior efficiency even in the case thinning has been made. <P>SOLUTION: When the battery pack is manufactured provided with a first case half body 12 in which a welding rib 16 is formed, a second case half body 14 in which a welding face 18 to which the welding rib 16 is welded is formed, and the battery 10 which has been housed in the first case half body 12 and the second case half body 14 to which the welding rib 16 and the welding face 18 are welded, a projection is inserted into an opening part 20 which has been formed beforehand in the vicinity of the welding rib 16 of the first case half body 12, and the welding rib 16 and the welding face 18 are welded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes a first case half formed with a welding rib, a second case half formed with a welding surface, a first case half and a second case half formed by welding the welding rib and the welding surface. The present invention relates to a battery pack including a battery housed in a body and a method for manufacturing the battery pack.

  As a driving power source for a small electronic device or a portable electronic device, a battery pack in which a battery to which a protective circuit board is attached is housed in a synthetic resin case is used. The battery pack integrates the divided first case half and second case half by ultrasonic welding or the like, and accommodates the battery 10 therein. For example, a protruding welding rib is formed on the first case half, a welding surface to be welded to the welding rib is formed on the second case half, and the welding rib is ultrasonically welded to the welding surface. The body and the second case half are integrated. FIG. 4A is a cross-sectional view showing an example of ultrasonic welding of the first case half and the second case half. The first case half 2 is supported by the receiving jig 8, and vibration is applied to the second case half 4 from the horn 6. In FIG. 4A, the batteries in the first case half 2 and the second case half 4 are omitted.

However, the position of the welding rib may be shifted due to the pressure or vibration applied to the second case half 4 from the horn 6 and the welding may not be performed normally. Therefore, a drop prevention rib is provided on the inner side (battery side) of the weld surface so that the weld rib does not fall from the weld surface. As another method, a V-shaped protrusion is formed at the tip of the welding rib and a V-shaped groove is formed on the welding surface (see, for example, Patent Document 1).
JP 2002-245993 A

  In recent years, with the miniaturization of small electronic devices or portable electronic devices, it has been strongly desired to reduce the size of the battery pack built therein. In the downsizing of the battery pack, not only the downsizing of the battery but also the downsizing of the case is performed, and the case tends to be thinned. When the case is thinned, the above-described drop-off preventing ribs or V-shaped grooves can hardly be formed.

  FIG. 4B is a cross-sectional view showing an example of ultrasonic welding of the thinned first case half and second case half. When the case halves 2 and 4 are thinned to, for example, 0.8 mm or less, the strength of the case halves 2 and 4 is reduced, so that the welding energy escapes due to the occurrence of blurring during ultrasonic welding. Defects are likely to occur. FIG. 5A and FIG. 5B are enlarged cross-sectional views of main parts showing examples of poor welding. In FIG. 5 (a), the weld rib is displaced from the weld surface, resulting in a defect that is not welded (unwelded). In FIG. Has occurred. Further, since the welding energy escapes, it is necessary to apply vibration energy larger than usual in order to melt the welding rib, and there is a problem that unnecessary vibration energy is applied to an internal part such as a battery (not shown) to cause damage.

  The present invention has been made in view of such circumstances, and by providing an opening in the vicinity of the welding rib or the welding surface and inserting a projection into the opening to weld the welding rib and the welding surface, the thickness is reduced. It is an object of the present invention to provide a battery pack and a method for manufacturing the battery pack that can be efficiently welded even in such a case.

  Moreover, this invention sets it as the structure which made the 1st case half body and the 2nd case half body which welded the welding rib and the welding surface into frame shape, and wound the sheet | seat around the 1st case half body and the 2nd case half body. Another object is to provide a battery pack that can be further reduced in size.

  The battery pack according to the first aspect of the present invention includes a first case half formed with a protruding welding rib, a second case half formed with a welding surface on which the welding rib is welded, the welding rib, and the In a battery pack comprising a first case half and a battery accommodated in a second case half welded on the welding surface, an opening into which a protrusion is inserted at the time of welding is provided in the vicinity of the welding rib or the welding surface. It is characterized by having.

  A battery pack according to a second invention is the battery pack according to the first invention, wherein the first case half and the second case half welded to the welding rib and the welding surface are frame-shaped, and the first case half and the second case It is characterized by comprising a sheet wound around a half body.

  According to a third aspect of the present invention, there is provided a battery pack manufacturing method comprising: a first case half formed with a protruding welding rib; a second case half formed with a welding surface to which the welding rib is welded; and the welding. In a manufacturing method of a battery pack comprising a rib and a battery accommodated in the first case half and the second case half welded to the welding surface, the welding rib of the first case half or the second case half A protrusion is inserted into an opening formed in the vicinity of the welding surface, and the welding rib and the welding surface are welded.

  In the first and third inventions, an opening into which a protrusion is inserted at the time of welding is formed in the vicinity of the welding rib or the welding surface, and the welding rib and the welding surface are welded with the protrusion inserted into the opening. To do. At the time of welding, vibration energy is applied to the welding rib or the welding surface, for example, vibration due to ultrasonic welding is applied. At that time, when the first case half and the second case half are thinned to, for example, 0.8 mm or less, the strength is reduced, so that the first case half and the second case half are easily deformed. Fluctuates. However, when a projection is inserted into the opening in the vicinity of the welding rib or the welding surface, the projection holds the opening while pressing the opening toward the welding portion, so that the position variation of the welding rib or the welding surface is suppressed. Since the position of the welding rib or the welding surface does not fluctuate, the welding can be efficiently performed with the applied vibration energy.

  In the second invention, the first case half and the second case half welded to the welding rib and the welding surface are frame-shaped, and a sheet is wound around the first case half and the second case half containing the battery. Therefore, the size of the battery pack can be reduced as compared with the case where the welded first case half and second case half are box-shaped. Moreover, since the opening is covered with the sheet by winding the sheet, the opening can be prevented from being exposed to the appearance, and the battery outer body is not exposed. Even so, a short circuit can be prevented. However, in the case of the frame shape, the strength of the case itself is lower than in the case of the box shape, so that the position of the welding rib or the welding surface is likely to fluctuate during welding. However, as described above, in the present invention, since the opening into which the projection is inserted at the time of welding is formed in the vicinity of the welding rib or the welding surface, the position of the welding rib or the welding surface varies at the time of welding. Can be prevented.

  According to the first and third inventions, the welding rib or the welding surface can be efficiently welded even when the thickness is reduced, and the welding processing time can be shortened compared to the prior art, or stable welding can be achieved. It is possible to reduce welding defects.

  According to the second invention, the size of the battery pack can be further reduced.

Hereinafter, the present invention will be specifically described with reference to the drawings illustrating embodiments thereof.
FIG. 1A is an exploded perspective view showing an example of a battery pack before welding, and FIG. 1B is an enlarged view of an opening portion to be described later of the exploded perspective view shown in FIG. In FIG. 1A, 12 is a first case half, 14 is a second case half, and 10 is a battery. The battery 10 has a rectangular parallelepiped shape, and a protective circuit board 10a is disposed on one side surface. The battery 10 has a width of 40 mm, a vertical width of 30 mm, and a height of 5 mm.

  The first case half 12 and the second case half 14 are U-shaped, and the U-shaped tip portions are opposed to each other and are ultrasonically welded to be integrated. The battery 10 is housed in a rectangular frame (the integrated first case half 12 and second case half 14) so as to surround the side surface. Note that the protruding lengths of the two opposing U-shaped planes are shorter for the second case half 14 and longer for the first case half 12.

  Protruding welding ribs 16 are formed at both ends of the U-shaped first case half 12, and the welding ribs 16 are welded to both ends of the U-shaped second case half 14. A welding surface 18 is formed. In addition, a rectangular opening 20 is formed in the vicinity of both ends of the first case half 12. The first case half 12 and the second case half 14 are made of synthetic resin, and for example, polycarbonate and / or ABS (Acrylonitrile Butadiene Styrene) are used. The thicknesses of the two opposing flat surfaces of the first case half 12 and the second case half 14 are 0.3 to 0.8 mm, and the size of the welding rib is 3 mm wide and 1.5 mm high. is there. The size of the opening 20 is 3 mm × 2 mm.

  FIG. 2A is a cross-sectional view showing an example of ultrasonic welding of the first case half 12 and the second case half 14 according to the present invention. In addition, although it is the sectional view on the AA line of Fig.1 (a), the battery 10 is abbreviate | omitted. The central plane of the U-shaped first case half 12 is arranged on a flat aluminum receiving jig 32, and the two opposing planes sandwiching the central plane are movable aluminum receiving jigs 34, 34. The movable receiving jigs 34 and 34 include protrusions 36 and 36 inserted into the openings 20 and 20 of the first case half 12, move from the left and right toward the first case half 12, and the protrusions 36 and 36. Is inserted into the openings 20 and 20.

  The second case half is arranged so that the welding surfaces 18, 18 are in contact with the welding ribs 16, 16 of the first case half 12, and the required high frequency from the horn 30 to the second case half 14. Is applied to the second case half 14, and the welding rib 16 and the welding surface 18 are melted. When the application of the high frequency is finished, the temperature of the melted portion gradually decreases, and the welding rib 16 of the first case half 12 and the welding surface 18 of the second case half 14 are welded and integrated.

  In the welding process, the projection 36 of the receiving jig 34 is inserted into the opening 20 of the first case half, and pressure is applied to the opening 20 from the projection 36 toward the welding portion (welding surface). The periphery of the welding rib 18 of the one case half 12 is supported by the protrusion 36. Therefore, the vibration of the welding rib 18 hardly occurs with respect to the vibration applied from the horn 30, and the vibration energy is efficiently used for welding. For example, when the same ultrasonic welding machine is used, when the energy supply set value (power value) of a conventional product without an opening is 100%, the energy supply set value is 20% in the present invention having an opening. Can be welded. That is, 80% of the conventional product is wasted energy. Therefore, welding can be performed in a short time, and poor welding can be reduced. Note that the vibration energy can be obtained based on, for example, vibration time and vibration amount necessary to complete the welding normally. Moreover, since the formation part of the opening part 20 is a product made from a synthetic resin and the protrusion 36 is metal, both will not weld, but the clearance and welding conditions of the opening part 20 and the protrusion 36 should be set suitably. Thus, the synthetic resin around the opening 20 can be prevented from melting.

  A label is finally wound around the battery in which the first case half 12 and the second case half 14 have been welded. FIG. 2B is a perspective view showing an example of a battery pack around which a label is wound. In the example of FIG. 2B, the label 22 is wound around the plane on which the first case half 12 and the second case half 14 are welded and the front and back surfaces of the battery 10.

  In the above-described embodiment, the shape of the opening is a quadrangle, but the shape of the opening can be any shape, for example, a triangular shape or an elliptical shape. FIG. 3A is a plan view showing another example of the opening. In the example of Fig.3 (a), the welding rib 16 side of the opening part 20 is made into linear shape, and the other part is made into curve shape.

  Further, in order to prevent blurring of the welding rib 16 at the time of ultrasonic welding, the protrusion only needs to support at least the welding rib 16 side of the opening 20. For this reason, the shape of the opening and the cross-sectional shape of the protrusion do not have to be completely the same. For example, it is possible to insert a protrusion having a triangular cross section with the weld rib side as a base into the quadrangular opening.

  In the above-described embodiment, the welding rib 16 is formed on the first case half 12 and the welding surface 18 is formed on the second case half 14, but the welding surface is formed on the first case half 12. It is also possible to form welding ribs on the second case half 14. Moreover, the shape of a welding rib and a welding surface is not specifically limited, It can be made into arbitrary shapes. FIG. 3B is a cross-sectional view showing another example of the welding rib and the welding surface. In the example of FIG. 3B, the front end portions of the two opposing planes of the U-shaped first case half are directly used as the welding ribs 16.

(A) is an exploded perspective view which shows the example of the battery pack before welding, (b) is an enlarged view of the opening part of the exploded perspective view shown to (a). (A) is sectional drawing which shows the example of the ultrasonic welding of a 1st case half body and a 2nd case half body, (b) is a perspective view which shows the example of the battery pack by which the label was wound. (A) is a top view which shows the other example of an opening part, (b) is sectional drawing which shows the other example of a welding rib and a welding surface. It is sectional drawing which shows the example of the ultrasonic welding of the conventional 1st case half and 2nd case half. It is a principal part expanded sectional view which shows the example of a welding defect.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Battery 12 First case half 14 Second case half 16 Welding rib 18 Welding surface 20 Opening 22 Label 30 Horn 32 Jig 34 Movable jig 36

Claims (3)

A first case half formed with a protruding welding rib, a second case half formed with a welding surface to which the welding rib is welded, and a first case half welded with the welding rib and the welding surface. A battery pack comprising a body and a battery housed in a second case half,
A battery pack comprising an opening into which a protrusion is inserted at the time of welding in the vicinity of the welding rib or the welding surface. The first case half and the second case half welded to the weld rib and the weld surface are frame-shaped,
The battery pack according to claim 1, further comprising a sheet wound around the first case half and the second case half. A first case half formed with a projection-like weld rib, a second case half formed with a weld surface to which the weld rib is welded, and a first case half welded with the weld rib and the weld surface. A battery pack comprising a body and a battery housed in a second case half,
A battery pack, wherein a protrusion is inserted into an opening formed in advance in the vicinity of a welding rib of the first case half or a welding surface of the second case half, and the welding rib and the welding surface are welded. Production method.

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