JPS637662B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for connecting cells in a lead-acid battery, particularly a small sealed lead-acid battery in which the inter-cell connection space in the upper part of the cell chamber is narrow and limited. The object of the present invention is to provide a method that can be used without causing deterioration of battery performance such as corrosion of pole parts.

With the remarkable development of cordless devices in recent years, many small sealed lead-acid batteries have come to be used as power sources for these devices.

For cell-to-cell connections in small sealed lead-acid batteries, the connection space above the battery is narrow and limited, so the connection lead poles of the cells located on both sides of the battery case partition wall should be placed above the top of the partition wall. The so-called overpartition method is mainly used, in which the partition wall is extended over the partition wall and connected at the top.

At this time, copper wire or tinned copper wire was used for the connection between the poles, and the connection body and the tips of the poles were connected by melting the surface portions of the ends of the poles with a soldering iron.

However, in this type of small battery, when assembling the electrode plate group into each cell chamber of the battery case, the electrode plate group that has been chemically formed is often used, and for this reason, the surface of the pole pole for connection between the cells of each electrode plate group is is covered with an oxide film, and its melting temperature is higher than that of the lead or lead alloy that forms the pole. Therefore, the temperature of the tip of the soldering iron is set to 400°C, which is enough to simply melt the lead or lead alloy of the pole. If the temperature was kept at ~450°C, the pole pillars were not sufficiently melted due to the presence of an oxide film, and reliable welding with the connecting body could not be achieved.

Therefore, when performing soldering work at the iron tip temperature of 400 to 450°C, it is necessary to remove the oxide film on the pole part, and use a highly corrosive flux. After that, the oxide was removed, and then the connection body and pole column were welded together.

However, flux is highly corrosive, and if it enters the battery it will have an adverse effect, and if flux remains attached to the tips of the poles at the connections between cells, the joints may be damaged when the product is released on the market. There was a risk that the cells would gradually corrode and the connections between the cells would break when an overcurrent or large current flows. These phenomena are observed not only in batteries but also in general electronic devices that use soldering.

In addition, soldering work falls under the category of schizophrenia, which has been cited as an occupational disease in recent years.In particular, soldering the connections between storage battery cells is at high temperatures, and if you wear gloves and do this work all day long, your hands may become hot. Manual soldering is not the preferred method for connecting cells in terms of product quality and labor, as it can cause numbness and even cause blisters in some people.

In order to solve these problems, even if the soldering work was mechanized, the soldering part would not have a long life, and since a highly corrosive flux was used, the copper on the tip would quickly wear out and the wire connection would be damaged. The welding part with the lead pole column was not welded cleanly, and the iron tip had to be replaced every 1 to 2 hours, resulting in a machine with extremely low operating rates, making it impossible to put it to practical use. Ta.

The present invention provides a method for manufacturing lead-acid batteries characterized by an intercell connection method that solves these problems.The present invention is characterized by the ability to produce lead-acid batteries instantly by high temperatures caused by arc generation without using flux. The purpose is to remove the oxide film on the surface of the pole pole and weld the ends of the pole poles located on both sides of the battery case partition wall to the connection body made of metal wire that is being passed between them.

Normally, when connecting cells by welding, the oxide film on the surface of the lead pole column is removed by brush polishing or the like before welding, but the present invention eliminates the need for such pretreatment at all. The lead pole column and the linear connector can be welded by a simple method.

Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a schematic cross-sectional view of a small sealed lead-acid battery before sealing, in which cells are connected using an overpartition method according to the manufacturing method of the present invention. The single battery (cell), 3 is a battery case partition wall, and 4 is an inner lid, has a partition wall (not shown) that corresponds to the partition wall 3 and partitions the cell chambers in a liquid-tight manner. Reference numeral 5 denotes an upper lid, and snap terminals 6 of both positive and negative poles provided thereon are connected by lead wires 8 to input/output pole columns 7 of cells at both left and right ends. In addition, pole columns 9 and 1 for inter-cell connection are located on both the left and right sides of each partition wall 3.
0 is connected by a connecting body 11 made of copper wire.

FIG. 2A shows a state before connection in which the connecting body 11 is pressed against the tips of the pole posts 9 and 10 in FIG.
B and C show the state in which the inter-cell connection has been completed, and C is an example in which a holding groove 10' for the connecting body 11 is provided in advance at the tip of the pole column, and the connecting body 11 is placed in the holding groove 10'.
After that, an arc is blown to weld the tip of the pole pole and the end of the connecting body 11.

The connection between the cells is made by ejecting an arc from the arc electrode 12 without contacting the pressed portion between the tip of the pole column and the connecting body 11, and connecting a part of the connecting body 11 and a part of the tip of the pole column. Welding is carried out by heating the material locally to a high temperature. At this time, the distance between the arc electrode and the welding part may be 5 to 10 mm, the welding current may be 1 to 5 A, and the energization time may be 0.2 to 1.0 seconds. In addition, when using copper wire for the connection body, it is better to apply a thin layer of tin plating or solder plating, which is more compatible with molten lead and copper than bare wire, for more reliable welding. This can be done without the line slipping out of the pole.

In this way, in the cell-to-cell connection method of the present invention, since the heat generated by the electric arc is used to connect the tips of the pole poles with the connection body in a non-contact state, there is no risk of wear and tear on the soldering iron tips as in soldering. There is no need to replace or use flux, and the high temperature of the arc allows for instantaneous removal of the oxide film on the pole pillars, making it possible to connect cells with extremely high workability, and to avoid the narrow constraints on the connection space between cells. The cell-to-cell connection work in a small-sized sealed lead-acid battery is easy, and furthermore, a small-sized sealed lead-acid battery with excellent performance can be manufactured with less voltage drop at the connection between cells after the battery is formed.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of a small sealed lead-acid battery before sealing in which cells are connected in an embodiment of the present invention;
Diagram A is an explanatory diagram of the connection body pressed against the tip of the pole column,
FIG. 2B is an explanatory diagram of a completed cell-to-cell connection, FIG. 2C is an explanatory diagram of an example in which a connecting body holding groove is provided at the tip of a pole column, and FIG. 3 is an explanatory diagram of arc welding. 1... Battery case, 2... Cell battery, 3... Partition wall,
9, 10... Connection pole pole, 11... Connection body, 12
...Arc electrode.

Claims (1)

[Claims] 1. In the inter-cell connection method in which the connection poles 9 and 10 of the unit cells 2 located on both sides of the battery case partition wall 3 are respectively extended above the upper end of the partition wall and their tips are connected to each other, the above-mentioned A metal wire 1 with a low electrical resistance value is placed between the tips of the connection poles 9 and 10 on both sides of the partition wall 3.
A method for manufacturing a lead-acid battery, characterized in that the tips of the pole columns 9 and 10 and the metal wire 11 are arc welded to connect the tips of the pole columns.