JP2001325927A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack with further compactness realized maintaining strength of a casing. SOLUTION: The battery pack 1 comprises a lithium battery 2, a casing 3 which can contain the lithium battery 2, a board 5 provided with a circuit protecting the lithium battery 2, and a cover 4 covering an opening part 3A of the casing 3. The casing 3 is integrally formed with conductive aluminum by a deep drawing process. The manufacturing of the battery pack 1 is completed by inserting the lithium battery 2 from the opening part 3A and then, putting together the cover 4 here containing the board 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a battery pack.

[0002]

2. Description of the Related Art In recent years, secondary batteries such as lithium batteries are often used in electronic devices such as mobile phones. The secondary battery is housed in a resin casing together with a printed circuit board provided with a protection circuit, and is mounted on an electronic device as a battery pack. By the way, when trying to reduce the size of an electronic device, it is necessary to simultaneously reduce the size of the battery pack housed therein. Here, in order to reduce the size of the battery pack, it is easier to reduce the size of the casing than to reduce the size of the secondary battery itself. In the past, the size of the battery pack has been reduced by reducing the thickness of the resin casing or by forming the casing into a perforated shape.

[0003]

However, when a thin rectangular parallelepiped casing is formed of resin, there is a demand for a mold (for example, since it is necessary to provide a taper in the direction of removing the mold, In the case of forming an elongated product such as a casing, there is a limit to reducing the thickness at the tip of the mold.) It was difficult to do. For this reason, the casing has to be divided into a plurality of members and must be formed, and the number of steps such as bonding them has to be increased. Further, if the size of the casing is excessively reduced, the strength of the casing is reduced beyond a predetermined value. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery pack that can be downsized while maintaining the strength of a casing. Another object is to provide a battery pack that can simplify the manufacturing process.

[0004]

According to a first aspect of the present invention, there is provided a battery pack comprising: a secondary battery;
A casing capable of accommodating the secondary battery and a cover capable of covering an opening of the casing are provided, wherein the casing is formed of a metal material. According to a second aspect of the present invention, in the first aspect, the casing is formed by drawing a metal plate. The invention according to claim 3 is the invention according to claim 1 or 2, wherein a substrate provided with a protection circuit for the secondary battery is housed inside the casing. I do.

[0005]

According to the first aspect of the present invention, since the casing is formed of a metal material, it is possible to reduce the size while maintaining strength as compared with a conventional resin casing. Becomes According to the second aspect of the present invention, since the metal casing is formed by deep drawing, a step of bonding a plurality of members to produce a resin casing as in the related art is not required, so that the entire structure is eliminated. Can be simplified. According to the third aspect of the present invention, since the board provided with the protection circuit is housed inside the casing, an electromagnetic shielding effect on the protection circuit can be obtained.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment Next, a first embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 shows an exploded view of the battery pack 1 of the present embodiment. The battery pack 1 includes a lithium battery 2 as a chargeable / dischargeable secondary battery, a casing 3 capable of accommodating the lithium battery 2, a cover 4 capable of covering an opening 3A of the casing 3, A substrate 5 on which a protection circuit for the battery 2 is mounted is provided. The outer wall 7 of the lithium battery 2 is formed of a conductive metal in a thin rectangular parallelepiped shape, and contains therein an active material and a separator (not shown in detail) constituting the secondary battery. As shown in FIG. 2, a small opening 7A is provided on one surface side (the surface side shown in FIG. 1) of the outer wall 7, and a partition member 8 made of an insulating resin is mounted on the small opening 7A. A pole member 9 made of a conductive metal is assembled in the center of the front surface side of the partition member 8 in a state of being electrically partitioned from the outer wall 7. In the center of the partition member 8, an insertion hole 8A is provided.
A wire 10 for connecting one pole side inside the outer wall 7 and the pole member 9 is inserted therethrough. The outer wall 7 itself constitutes the pole side opposite to the pole member 9.

The casing 3 is integrally formed in a thin rectangular parallelepiped shape capable of accommodating the lithium battery 2 by deep-drawing a conductive metal material, for example, a plate material such as aluminum. The size of the internal space of the casing 3 has a slight clearance in the thickness direction with respect to the thickness of the lithium battery 2, while the size of the substrate 5 in the depth direction is the same as that of the lithium battery 2. It is formed as long as it can accommodate. Also, the casing 3
Is provided with an opening 3A on one surface side, and the lithium battery 2 and the like are accommodated through the opening 3A.

The substrate 5 is, for example, a printed circuit board having a glass epoxy resin as an insulating layer. On the side facing the lithium battery 2, as shown in FIG. And a pair of connecting portions 11A and 11B that can be electrically connected to each other. Also, the substrate 5 includes
A predetermined electronic component 12 is mounted, and forms a protection circuit (for example, a protection circuit against overcharge and heat dissipation) of the lithium battery 2 together with the copper foil of the printed circuit board. In the vicinity of the upper end on the front side (left side in FIG. 2) of the substrate 5, four terminal portions 13 are provided at equal intervals. When the battery pack 1 is mounted on an electronic device (not shown), these terminal portions 13 can be connected to terminals on the electronic device side. The terminal section 13 is provided with a thermistor terminal and a control terminal in addition to the positive and negative electrodes.

The cover 4 is integrally formed of an insulating resin so as to cover the opening 3A of the casing 3. The cover 4 is provided with a bottom 14 having substantially the same shape as the opening 3A, and a side wall 15 erected from each side of the bottom 14 toward the casing 3. The thickness of the side wall portion 15 is reduced with a step 15A on the way.
The insertion portion 15B at the distal end is inserted into the opening 3A. Further, the substrate housing space 1 surrounded by the bottom portion 14 and the side wall portion 15
The substrate 5 can be accommodated in 7. Further, four terminal openings 16 are opened in the vicinity of the connection portion between the side wall portion 15 and the bottom portion 14 on the upper side in the figure. These terminal openings 16 are provided in alignment with the positions of the terminal portions 13 of the substrate 5.

Next, the operation and effect of the embodiment constructed as described above will be described. First, the lithium battery 2 is inserted through the opening 3A of the casing 3. At this time, the lithium battery 2 is pushed into the casing 3 so that the pole member 9 faces the opening 3A.

On the other hand, the substrate 5 is inserted into the substrate accommodating space 17 of the cover 4. At this time, the terminal portion 13 of the substrate 5
The cover 4 faces the outer surface side from the terminal opening 16. In this state, the insertion portion 15B of the cover 4 is
Cover 4 and casing 3
And assemble. An adhesive or the like is applied between the insertion portion 15B and the edge of the opening 3A so that the members 3 and 4 are not separated. Thus, when the assembling operation of the two members 3 and 4 is completed, the connecting portions 11A and 11
B is connected to the outer wall 7 and the pole member 9 of the lithium battery 2,
The manufacture of the battery pack 1 is completed.

As described above, according to this embodiment, since the casing 3 is formed of a metal material, it is possible to reduce the size while maintaining strength as compared with a conventional resin casing. In addition, the metal casing 3
Since the metal plate is formed by deep drawing, a step of bonding a plurality of members and manufacturing a resin casing as in the related art is not required, so that the entire manufacturing process can be simplified. Furthermore, since the board 5 provided with the protection circuit is housed inside the casing 3, an electromagnetic shielding effect on the protection circuit can be obtained.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS.
In the present embodiment and the first embodiment, the same components are denoted by the same reference numerals, and the description is omitted. The main difference between the present embodiment and the first embodiment is the position of the terminal portion 21 and the terminal opening 20. In the embodiment, the terminal openings 20 of the cover 4 are formed in a row at the center of the bottom portion 14, and the terminal portions 21 of the substrate 5 are provided in alignment with the positions of the terminal openings 20. With the battery pack 22 configured as described above, the same operation and effect as in the first embodiment can be achieved.

The technical scope of the present invention is not limited by the above-described embodiments, and for example, the following ones are also included in the technical scope of the present invention. In addition, the technical scope of the present invention extends to an equivalent range. (1) In the above embodiment, the casing 3 is made of aluminum. However, according to the present invention, the casing can be made of another metal material, for example, iron or titanium. In addition, as the metal material of the casing, not only one kind of metal material but also various alloy materials can be used.

(2) In the above embodiment, the casing 3 is formed integrally by deep drawing. However, according to the present invention, the casing 3 may be bent by using an adhesive means such as welding. You may comprise from several metal members. (3) In the above embodiment, the lithium battery 2 is used as a secondary battery. However, according to the present invention, a secondary battery such as a nickel cadmium battery or a nickel hydride battery may be used.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a battery pack according to a first embodiment.

FIG. 2 is an exploded side sectional view of the battery pack.

FIG. 3 is a perspective view of a battery pack.

FIG. 4 is an exploded perspective view of a battery pack according to a second embodiment.

FIG. 5 is a perspective view of a battery pack.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Battery pack 2 ... Lithium battery (secondary battery) 3 ... Casing 3A ... Opening 4 ... Cover 5 ... Substrate

Claims (3)

[Claims] 1. A battery pack provided with a secondary battery, a casing capable of housing the secondary battery, and a cover capable of covering an opening of the casing, wherein the casing is formed of a metal material. A battery pack characterized in that: 2. The battery pack according to claim 1, wherein the casing is formed by drawing a metal plate. 3. The battery pack according to claim 1, wherein a substrate provided with a protection circuit for the secondary battery is accommodated inside the casing.