JPH08241700A - Battery pack for secondary battery - Google Patents

Abstract

PURPOSE: To make quick assembling of a battery pack for secondary battery without adopting the ultrasonic fusion attachment method by locating the extended side face part of a lid member closely to the inside of an opening provided in a box member, and fitting a small projection on the outer side face of the lid member in a recess furnished at the inner side face of the box member. CONSTITUTION: An extended side face part 1b is formed in the direction perpendicular to the main surface from one of the short edges of a lid member 1, and three side faces are equipped with two minor projections 1a each. A box member 2 is provided with an opening 2b in rectangular shape etc., in one side plate of short edge and fitted with a stopper 7 which holds a pair of partitions 6 and two batteries located in the center, and three inner side faces are each furnished with two recesses 2a. When the lid member 1 is put on the box member 2, the projections 1a are fitted in the recesses 2a, and the surface 1b of the member 1 is fitted between the opening side side-plate of the member 2 and the partition 6 so that the two members 1, 2 are consolidated. It may also be accepted that such minor projections 1a and recesses 2a are furnished on/in opposite members. It is preferable that a charge/discharge terminal 1c and leads are formed in a single piece with one of the members 1, 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack of a secondary battery used as a power source for mobile phones and personal computers.

[0002]

2. Description of the Related Art Rechargeable batteries such as nickel-cadmium batteries, nickel-hydrogen batteries, and lithium-ion batteries, that is, secondary batteries, are typified by portable personal computers, mobile phones, video cameras, and the like, which are trying to be compact and lightweight. It is widely used as a power source for cordless type consumer devices.

When a secondary battery is used as a power source for these consumer appliances, it is rarely used alone. In many cases, a plurality of batteries are combined with peripheral circuits such as a protection circuit and a capacity detection circuit to house the batteries in a dedicated battery pack. Further, conventionally, the terminals and the leads are parts separate from the battery pack and are directly connected to the electrodes of the battery by spot welding.

The housing of the conventional battery pack is assembled by fusing a plurality of plastic molded parts by ultrasonic welding. The reason why the ultrasonic welding method is used for assembling the battery pack is that first, an additive such as an adhesive is not required, and secondly, the work efficiency is good because the welding time is short.
Third, easy to automate and suitable for mass production, fourth
This is because there are advantages such as that the necessary bonding strength can be obtained.

[0005]

However, in the assembly of the battery pack by the ultrasonic fusion method, when the wall thickness of the plastic molded part is large, the output power for fusion becomes large, and the secondary power in the battery pack is increased. It may deteriorate the battery or adversely affect the electronic components built into the battery pack. In particular, the lithium-ion battery is said to be weak against the ultrasonic fusion method, so that the output power cannot be increased.

On the other hand, when the thickness of the plastic molded part is small, it is necessary to align the joint surface to be ultrasonically fused with high accuracy, and it takes time to set up the ultrasonic fusion machine at the time of starting mass production. It is not suitable for high-mix low-volume production. In addition, if the alignment of the joining surfaces to be ultrasonically fused is not appropriate, the entire surface may not be fused and an unfused portion may occur, resulting in a defective product. Further, ultrasonic welding of a thin object or a poorly aligned joint surface with high output causes burrs, which increases the number of steps for removing burrs and lowers productivity, and also causes poor appearance and causes quality control problems. .

The present invention has been made to solve the above problems, and it is an object of the present invention to provide a battery pack of a secondary battery suitable for automation which can be assembled in a short time without using the ultrasonic fusion method. To aim.

[0008]

A battery pack for a secondary battery according to the present invention is a battery pack for a secondary battery having terminals for charging / discharging for connecting the secondary battery to a circuit. A box member having an opening portion for accommodating and holding a plurality of secondary batteries, a lid member having an extending side surface portion extending from at least one side in a direction substantially orthogonal to the main surface, and the box member And a charging / discharging terminal provided on at least one of the lid member, a recess formed on the inner side surface portion of the box member or the outer side surface portion of the lid member, and the outer side surface portion of the lid member or the inside of the box member. Small protrusions formed on the surface,
When the lid member is covered with the box member, the extended side surface portion is located in the vicinity of the inside of the opening portion, and the small protrusion is fitted in the recess.

In this case, the charging / discharging terminal and the lead wire are integrally formed on at least one of the box member and the lid member,
It is desirable that part of the lead wire or part of the charging / discharging terminal is exposed on the inner surface side of at least one of the box member and the lid member.

[0010]

In the battery pack of the secondary battery according to the present invention, when the lid member is covered with the box member, the small projections are fitted in the recesses, so that the lid member and the box member are firmly integrated, The secondary battery is securely held in the.

On the other hand, when the lid member is covered with the box member, the extended side surface portion is fitted between the side surface of the box member and the partition member, and the integration of the lid member and the box member is strengthened. Further, the charging / discharging terminal and the lead wire are integrally formed with at least one of the box member and the lid member, and a part of the lead wire or a part of the charging / discharging terminal is provided on the inner surface side of at least one of the box member and the lid member. Since the battery is housed, the electrodes of the battery come into contact with these exposed portions when the battery is housed, and the battery can be electrically connected to the electronic circuit through the discharging terminal. By integrally molding the terminals and the lead wires into the housing member in this manner, the conventional soldering or spot welding becomes unnecessary.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In this embodiment, a case of a battery pack for a lithium ion battery will be described. As shown in FIG. 1, a battery pack of a secondary battery is a combination of a lid member 1 and a box member 2, and when the lid member 1 is put on the box member 2, one unit housing is formed. As shown in FIG. 5, the battery pack can accommodate four secondary batteries 8.

As shown in FIGS. 2 to 4, the lid member 1 is made of a plastic thin plate. An extending side surface portion 1b extends from one short side of the lid member 1 in a direction orthogonal to the main surface. When the lid member 1 is put on the box member 2, the extended side surface portion 1b is fitted into a gap formed between the partition wall 6 and the inner wall on the short side of the box member 2.

Two small projections (hooks) 1a are formed on the three side surfaces of the lid member 1 so as to project therefrom. When the lid member 1 is put on the box member 2, the small protrusions 1a are not covered by the box member 2.
It is adapted to be fitted in each of the recesses 2a. It is preferable that the cross section of the small protrusion 1a is a right triangle.

The lid member 1 is formed by insert-molding a metal thin plate such as copper, copper alloy, aluminum, aluminum alloy, nickel, nickel alloy and thin metal wire into a plastic thin plate. A part of the insert-molded thin metal plate is exposed on the outer surface side of the lid member 1, and the charge / discharge terminals 3, 4 are formed.
Is formed. Four charging terminals 3 are provided on the outer surface side of the extended side surface portion 1b. Two terminals 1c are provided on the short side facing the extended side surface portion 1b. These terminals 1c are located at positions where they can come into contact with the positive and negative electrodes after connecting the batteries 8 in series. The discharging terminal 4 is provided on the main surface of the lid member 1, and when the battery pack is attached to a device such as a VTR, it comes into contact with the terminal of the electronic circuit. These terminals 1c, 3 and 4 are electrically connected by a lead wire 5 to form a circuit. The thickness of the lid member 1 is 0.5 to
The thickness is preferably in the range of 1.5 mm, and particularly for thin-walled products, the thickness is preferably about 0.6 mm.

Next, the box member 2 will be described with reference to FIGS. The box member 2 is made of a relatively strong plastic plate for accommodating and holding the battery 8.
The box member 2 is composed of a bottom plate and four side plates, and a rectangular opening 2b is formed in the side plate located on one short side. In addition,
The opening 2b does not necessarily have to be rectangular, and may have various shapes such as a square, a triangle, an ellipse, an oval, and a circle.

As shown in FIG. 5, the box member 2 is provided with a pair of partitions 6 and a pair of stoppers 7. The pair of partitions 6 is a member for positioning and holding the two batteries 8 at both ends, and the pair of stoppers 7 is a member for positioning and holding the two central batteries 8.

There are two recesses 2a on the three inner surfaces of the box member 2.
Are formed one by one. When the lid member 1 is put on the box member 2, the small protrusions 1a of the lid member 1 are fitted into the respective recesses 2a.

The wall thickness of the box member 2 is preferably in the range of 1 to 2 mm, and particularly for thin products, it is preferably about 1 mm. Further, the box member 2 and the lid member 1 are preferably made of a resin such as ABS resin, epoxy resin, polypropylene, polyethylene, or plastic. Use of these materials facilitates insert molding of the terminals 1c, 3, 4 and the lead wire 5.

In the above embodiment, the charging / discharging terminal and the lead wire are integrally insert-molded on the lid member.
The present invention is not limited to this, and charging / discharging terminals and lead wires may be insert-molded in the box member.

Further, in the above embodiment, the extending side surface portion of one side of the lid member is fitted into the partition / inner wall gap of the box member, and the small projections on the three sides of the lid member are fitted into the recesses of the box member. Can be fixed to the box member.

Further, in the above-mentioned embodiment, the extending side surface portion is formed only on one side of the lid member, but the extending side surface portion has two sides, three sides,
You may increase to 4 sides. Providing a large number of extending side surface portions of the lid member in this way further improves the fitting strength.

[0023]

The battery pack of the secondary battery of the present invention can be assembled in a short time without using the ultrasonic fusion method and is suitable for high-mix low-volume production. It can be manufactured on an automated line.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a battery pack of a secondary battery according to an embodiment of the present invention.

FIG. 2 is a plan view showing a lid member of a battery pack.

FIG. 3 is a side view of a long side showing a lid member of a battery pack.

FIG. 4 is a short side view showing a lid member of a battery pack.

FIG. 5 is a plan view showing a box member of the battery pack.

FIG. 6 is a side view of a long side of a battery pack box member.

FIG. 7 is a short side view showing a box member of a battery pack.

[Explanation of symbols]

1 ... Lid member, 1a ... Small projection, 1b ... Extended side surface part,
1c ... terminal, 2 ... box member, 2a ... recess, 2b ... opening, 3 ... charging terminal, 4 ... discharging terminal, 5 ... lead wire, 8 ... battery

Claims (2)

[Claims] 1. A battery pack of a secondary battery provided with charging / discharging terminals for connecting the secondary battery to a circuit, which has an opening on at least one side surface and stores and holds a plurality of secondary batteries. A box member, a lid member having an extended side surface portion extending from at least one side in a direction substantially orthogonal to the main surface, and a charging / discharging terminal provided on at least one of the box member and the lid member. And a recess formed on the inner surface of the box member or on the outer surface of the lid member, and a small protrusion formed on the outer surface of the lid member or the inner surface of the box member. A battery pack for a secondary battery, wherein when the box member is covered with the box member, the extended side surface portion is located in the vicinity of the inside of the opening portion, and the small protrusion is fitted in the recess. 2. A charging / discharging terminal and a lead wire are integrally formed with at least one of a box member and a lid member, and a part of the lead wire or a part of the charging / discharging terminal is at least one of the box member and the lid member. The battery pack of the secondary battery according to claim 1, wherein the battery pack is exposed to the inner surface side of the.