JPH0480505B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to improvements in sealed lead-acid batteries.

Conventional technology Conventionally, sealed lead-acid batteries have been made by stacking a certain number of positive electrode plates, negative electrode plates, and separators in a predetermined order to form an electrode plate group, which is then molded into a box-shaped synthetic resin electric cell made by injection molding. It was manufactured in storage.

Problems to be Solved by the Invention In recent years, devices using sealed lead-acid batteries have become smaller, and batteries are increasingly required to be lighter, smaller, and thinner. In order to meet these demands,
A structure as shown in Fig. 3, in which the electrode plate group is wrapped in a laminate film or sheet with low moisture permeability, has been proposed (Japanese Patent Laid-Open No. 60-205958,
60-230354).

In such a structure, in order to pressurize the electrode plate group, it must be housed in a rigid case such as a metal plate. However, in order to take advantage of the features of being lightweight, small, and thin, it is necessary to design the case to be as thin as possible. As a result, the pressurizing force of the case housing the storage battery acts on both edges of the electrode plate group in the width direction, so the case deforms into a shape in which the center of the electrode plate group in the width direction is slightly bulged. There is a problem in that the performance as a storage battery is impaired due to insufficient pressurization. To solve this problem, conventionally, as shown in Figure 4, a foamable synthetic resin such as urethane foam (hereinafter referred to as "sponge") was housed inside the case together with the storage battery, and the elasticity of the sponge allowed the electrode plates to be grouped together. A method was used to compensate for the decrease in pressurization in the center. In this case, it was necessary to prepare the sponge as a separate item when assembling the battery, which caused problems such as difficulty in automating battery assembly. The present invention aims to eliminate the above-mentioned problems and provide a structure that can satisfactorily pressurize a group of electrode plates without using a separate component such as a sponge.

Means for Solving the Problems In order to achieve this object, the sealed lead-acid battery of the present invention has the welded part of the laminate film located approximately at the center of the electrode plate group, and the welded ear part moved toward the center. Store it in the case folded.

As a result, the welded and bent portion of the laminate film fills the area in the center of the electrode plate group where the pressure is low, making it possible to obtain good pressure without using a sponge or the like as in the conventional case. can.

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

FIG. 3 shows a conventional proposal disclosed in the above-mentioned Japanese Patent Laid-Open Publication No. 60-205958. The electrode plate group is wrapped in two laminate films 10 and the periphery is welded. Such a storage battery is housed in a rigid case 11 as shown in FIG. 4 in order to pressurize the electrode plate group. At this time, since the center of the case 11 is deformed into a slightly bulging shape, the pressure applied to the center of the electrode plate group becomes small, so the sponge 12 is inserted and pressure is applied by the elasticity of the sponge 12.

The storage battery of the present invention is shown in FIGS. 1 and 2.

The synthetic resin cap 1 with the positive and negative electrode terminals 2, 2' buried and provided with the safety valve 4 is connected to the electrode plate group 6 at the positive and negative electrode ears 7, 7' by a method such as welding. The electrode plate group 6 is wrapped in a bag 8, and the bag 8 is welded to the cap 1 to form a storage battery.

At this time, the welded ear 13 of the bag 8 is located approximately in the center of the electrode plate group in the width direction, but it is moved slightly to one side (slightly to the right in FIG. It is stored in the case 11 in a state where it is bent toward the side (left side in FIG. 1).

A cross section when stored in the case 11 is shown in FIG. In the drawings, numeral 5 represents an upper lid disposed on the safety valve 4, numeral 3 represents an exhaust portion, and numeral 9 represents a welding portion.

Effects of the Invention Conventionally, a sponge was used to prevent the pressure from decreasing at the center of the electrode plate group, but in the storage battery of the present invention, the welded edges of the laminate film can achieve an effect with less variation in pressure. This eliminates the need for a sponge. This reduces costs, eliminates the need to handle soft objects such as sponges, improves productivity, and facilitates the automation of battery assembly work, which is of great industrial value.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the assembly of the storage battery of the present invention, FIG. 2 is a sectional view of the storage battery of the invention, FIG. 3 is a perspective view of a conventional structure, and FIG. 4 is a sectional view of a conventional structure. 1: cap, 6: electrode plate group, 8: laminate film bag, 11: case, 13: welding ear.

Claims (1)

[Claims] 1. In a sealed lead-acid battery in which a group of electrode plates is wrapped in a laminate film, the welding part of the laminate film is located at the center in the width direction of the group of electrode plates, and the welded ears are placed on the side closer to the center of the group of electrode plates. A sealed lead-acid battery that is folded and stored in a rigid case.