JP2596034B2 - Sealed lead-acid battery - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved connection between cells or a terminal lead-out structure of a sealed lead-acid battery used as a power source of a portable device or the like.

2. Description of the Related Art Conventionally, a sealed lead-acid battery of this type includes an electrode group 4 composed of a positive electrode plate 1, a negative electrode plate 2 and a separator 3 as shown in FIG. The edges of two tin-plated steel plates 7, 7 'each having a film 6 of a copolymer of ethylene and acrylic acid laminated on the inner surface thereof in contact with the frame 4 are thermally welded to the frame 5 for sealing, and the ears of the positive and negative plates are formed. 8, 8 'and the claws 9, 9' of the metal plate are welded to form a metal plate 7,
A safety valve 10 was attached to the frame 5 to make the cell 11 an input / output terminal 7 '. When arranging a plurality of cells on the same surface and integrating them, as shown in FIG. 5, solder metal plates 7 and 7 ″ of adjacent cells to each other using lead wires 12. Electrical connection and adhesive tape 13
The cells are fixed with a heat-shrinkable tube as shown in FIG.
The product was covered with 14.

 12 'and 12 "are terminal lead wires.

Problems to be Solved by the Invention However, in such soldering of the lead wire, even if the cell itself is thin, the thickness of the lead wire and the swelling of the solder substantially increase the battery thickness. Tears the heat-shrinkable tube,
There were problems such as damage to the film on the inner surface of the metal plates 7, 7 'due to the heat at the time of soldering, and detachment of the heat-welded portion with the frame.

Means for Solving the Problems In order to solve this problem, the present invention attaches a copper metal foil having an adhesive material on one side to a metal plate forming a terminal, and series spot welding the metal plate and the metal foil. To connect the cells.

Action With such a configuration, the battery can be made into an assembled battery without increasing the thickness of the battery almost, and there is no generation of a whisker at the welded portion that harms the heat-shrinkable tube that covers the assembled battery,
It is possible to perform welding in a short time while minimizing the thermal effect on the film and the frame body laminated on the inner surface of the metal plate.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

According to the present invention, as shown in FIG. 4, the electrode plate group 4 including the positive electrode plate 1, the negative electrode plate 2, and the separator 3 is surrounded by a polyethylene frame 5, and the inner surface in contact with the electrode plate group 4 is formed. Periphery and frame 5 of two tin-plated steel sheets 7, 7 'laminated with a copolymer film 6 of ethylene and acrylic acid
Are welded and sealed, and the lugs 8, 8 'of the electrode plates and the claws 9, 9' of the metal plates 7, 7 'are welded to make the metal plates 7, 7' a terminal. A safety valve 10 is attached to a part to form a cell 11, and three cells are arranged side by side as shown in FIG.
As shown in Fig. 2, a pair of welding electrodes 16, 16 'is attached to the copper foil, and a series spot welding is performed by attaching a pair of welding electrodes 16, 16' to the 7 " That is, a cell is placed on the same surface with a tape 13 with an adhesive, and the heat-shrinkable tube is fixed as shown in FIG.
14 to cover the battery.

Generally, in the case of spot welding, metals of the same series, for example, copper and brass, and iron and nickel are easy to weld because of their close melting points and resistances. Therefore, it is easy to spot-weld a nickel plate to a tin-plated steel plate, and it can be welded in a short time of about 1/60 second, so that there is almost no thermal effect on the film behind the metal plate. In addition, it was confirmed that even if a combination of a tin-plated steel sheet and copper was used, if the steel was formed into a foil having a thickness of 35 μm, the copper could be instantaneously heated in a short time of 1/60 second and welded to the tin-plated steel sheet without heat dissipation. Further, copper has an advantage that it can be made thinner by its electric resistance since it has a smaller electric resistance than nickel.

However, in the case of a copper foil having a thickness of about 35 μm, there is a problem that the copper foil moves from being placed on a metal plate to being spot-welded because it is thin and light. Therefore, movement of the copper foil can be prevented by pasting the copper foil with the adhesive to the metal part as a countermeasure. However, if there is an adhesive between the copper foil and the metal plate, current does not flow, so direct spot welding (one of the pair of electrodes is a metal plate to be welded,
The other was a problem that welding was not possible with the spot welding method applied to the copper foil, which is a welding material. However, by heating the copper foil to a high temperature in a short time by series welding, the adhesive material was vaporized and the copper foil and metal plate It has been confirmed that currents further flow when the metals contact each other, causing resistance heating and welding. Also,
Generally, when dissimilar metals are welded, moisture and the like infiltrate during use in high-humidity areas, causing local batteries to be easily corroded. However, there was an adhesive between the copper foil and the metal plate of the present invention around the welded portion, and the above problem could be solved by preventing infiltration of moisture.

Although not described in the drawings, the use of a thin 35 μm copper foil has flexibility, so it is possible to bend after spot welding, and even if overlapped, the thickness may be locally increased due to the thickness of the connection material. Since there was no cell, it became possible to stack cells in the thickness direction.

In addition, as a result of measuring the fusing current when a copper foil having a thickness of 35 μm and a width of 6 mm was used for connection between cells, it was found that the current was 100 A or more, and there was no particular problem in practical use.

As described above, according to the present invention, the inter-cell connector is made of a foil or a metal plate to reduce the thickness thereof, thereby reducing the outward protrusion after the inter-cell connection, eliminating breakage of the shrinkable tube and improving reliability. It has become possible to provide a highly reliable battery.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an assembled state of a sealed lead-acid battery according to one embodiment of the present invention, FIG. 2 is a cross-sectional view of a spot welded portion of an inter-cell connector according to the present invention, and FIG. FIG. 4 is a perspective view of a sealed lead-acid battery of the present invention, which is packaged with a battery, FIG. 4 is a perspective view of a cell before assembling, FIG. 5 is a perspective view of a conventional battery assembled, and FIG. FIG. 3 is a perspective view when a battery is mounted. 1 ... positive plate, 2 ... negative plate, 3 ... separator, 4 ...
... electrode group, 5 ... frame, 7,7 '... metal plate, 11 ... cell, 14 ... heat-shrinkable tube, 15 ... copper foil.

Claims (3)

(57) [Claims] An electrode plate group comprising a positive electrode plate, a negative electrode plate, and a separator is surrounded by a synthetic resin frame having heat welding property, and a synthetic resin film having heat welding property on an inner surface in contact with the electrode plate group. The peripheral edges of the two metal plates on which the sheets were laminated were thermally welded to the frame, and the positive / negative plates and the metal plate were electrically connected to each other, and the metal portion facing the outside of the metal plate was referred to as a terminal. A plurality of cells arranged on the same surface to electrically connect the metal plate and the metal plates of the other cells, wherein the connecting material of the metal plates between the cells is made of metal. A sealed lead-acid battery, wherein the connection between the metal plate and the metal foil is spot-welded. 2. The sealed lead-acid battery according to claim 1, wherein the metal foil is a copper foil having an adhesive material on one surface, and is adhered to the metal plate with an adhesive material. 3. The sealed lead-acid battery according to claim 1, wherein said spot welding is series welding.