JPS5910536B2 - Manufacturing method of cylindrical storage battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cylindrical storage battery, and in particular improves the insulation structure at the bottom of the spiral electrode group to improve workability during battery manufacturing and enable automatic assembly of the storage battery. The purpose is to

A cylindrical storage battery with a spiral plate group, such as a sealed nickel-cadmium storage battery, has a large battery capacity.
In the R-D and NR-F types, a spiral electrode plate group is formed, and two connection leads are provided at the upper and lower ends of the group, and one lead at the bottom is made of nickel-plated steel. It is often spot welded to the inside bottom of the case.

When spot welding these leads, there are problems such as burrs forming in the welded portion or bending or folding of the leads, which may damage the separator or come into contact with the counter electrode, causing an internal short circuit.

Therefore, normally, as shown in FIG. 5, a donut-shaped insulating plate 1 made of synthetic resin is applied to a separator 3 that slightly extends from the lower end face of the electrode plate group 2, and one electrode, for example, the cathode side, is 2
The insulation at the lower end of the electrode plate group can be improved by passing the book connection leads 4, 4' through the central hole 1' of the insulating plate 1, and by extending the other to the outside from the outside of the insulating plate. It was on.

Figures 6 and 7 show the electrode plate group to which this donut-shaped insulating plate is applied.For ease of understanding, the plate group is shown upside down from the actual electrode plate group, with the lower end of the electrode plate group facing upward. did. However, when using such a donut-shaped insulating plate, it is not possible to automatically supply the insulating plate to the end face of the electrode plate group, and the process of inserting the electrode plate group with the insulating plate applied into the battery case is difficult. In this case, the insulating plate may be misaligned from the electrode plate group, and the end of one lead 4 may not protrude from the central hole 1', making it impossible to reliably press the lead and the inner bottom of the case with the welding electrode rod. . Therefore, spot welding cannot be performed automatically.
There is a problem in that the position of the insulating plate must be inspected and adjusted every time, making the storage battery assembly process complicated and time-consuming. In the present invention, a heat-weldable separator having a width wider than the width of the electrode plates is interposed between the electrode plates, and the whole is wound to form a spiral-shaped electrode plate group, and the electrode plate group extends to at least the lower part of the electrode plate group. By thermally welding and hardening the excess separator portion, an insulating hardened surface integrated with the electrode plate group is formed at the bottom of the electrode plate group. To provide a manufacturing method in which a connecting lead of one pole can be easily pulled out to the center of the lower part of the electrode plate group, and a cylindrical storage battery can be automatically assembled with good workability.

Hereinafter, embodiments of the present invention will be described using a nickel-cadmium storage battery as well as the conventional example. First, as in the conventional example, a separator 3 made of polyamide nonwoven fabric or polypropylene nonwoven fabric, which is wider than these plates and has heat-weldability, is interposed between the band-shaped anode plate and cathode plate, and the whole is wrapped around a core. The electrode plate group 2 is formed by winding it into a spiral.

As a result, the excess portion 35 of the separator extends to at least one end, usually both ends, of the electrode plate group 2. By heating the surplus portion 3' of the separator using a donut-shaped hot plate (not shown) or the like having a through hole in the center to allow the winding core to escape, the surplus portions 37 are welded to each other, and by cooling. It hardens to become a doughnut-shaped hardened surface 5. At this time, the two leads 4, 4' extending downward from the lower end of the electrode plate group are guided by the donut-shaped hot plate and extend as they were, regardless of the welding of the separator excess portion 31. FIG. 1 shows a group of electrode plates constructed in this manner, and is shown upside down for clarity.

With this configuration, if this electrode plate group is inserted into the battery case in the normal state upside down as shown in the figure, the hardened surface 5 will not be displaced at all when inserted into the case.
Connection lead 4, 4! hits the inner bottom of the case and is bent as shown in Figure 2, so that its tip forms the hardened surface 5.
It comes to be located below the through-hole part 6 that exists in the center of. For this reason, welding of the leads 4, 4/ and the inner bottom of the battery case after inserting the electrode plate group into the battery case is as follows:
By inserting the welding electrode rod through the space left as a winding core trace in the center of the electrode plate group and the through hole in the center of the hardened surface corresponding to this space, the overlapping leads 4
, 4' and the inner bottom of the case can be integrated under pressure, and spot welding of the two can be easily performed without any trouble, and automation is also possible.

FIG. 3 is a perspective view showing a state in which such a donut-shaped hardened surface 5 is formed on the entire lower end surface of the electrode plate group, and in addition, as shown in FIG. When the electrode plate group is inserted into the case, it is bent and faces parallel,
Even if the welds 5' and 52 are formed partially, short circuits between the electrode plates at the bottom of the electrode plate group or short circuits caused by the leads 4, 4' coming into contact with the bottom of the counter electrode can be effectively prevented, and the lead ends Welding to the inner bottom of the battery case can be easily performed in the same manner as shown in FIGS. 1 and 2.

Of course, hardening of the excess separator part by thermal welding is necessary at the bottom end of the electrode plate group to insulate the inner bottom of the battery case and the lower part of the electrode plate group, but the excess separator part at the top end of the electrode plate group is also hardened. A similar treatment is preferable because it further ensures the binding of the electrode plate group and facilitates insertion into the battery case.

As described above, according to the manufacturing method of the present invention, when the electrode plate group is inserted into the battery case, the insulating plate does not shift its position unlike the conventional example, and the connection lead is inserted into the electrode plate group. Since it can be easily pulled out to the center of the lower part and welded to the inner bottom of the battery case, the battery assembly process can be performed automatically and with good workability.

[Brief explanation of drawings]

FIG. 1 is a side view of a spiral-shaped electrode group constructed by an embodiment of the manufacturing method of the present invention, FIG. 2 is a side view of one of the electrodes with its lead bent toward the center of the electrode group, and FIG. FIG. 4 is a perspective view of a plate group according to another embodiment, FIG. 5 is a perspective view of a conventional donut-shaped insulating plate, and FIG. 6 is a side view of a conventional plate group. FIG. 7 is a perspective view thereof. 2...Spiral plate group, 3'...Separator surplus part, 4, 4'...Connection lead, 5,
5', 5〃. ．． ．． Hardened surface of excess separator part due to heat welding, 6... Perforated part.

Claims (1)

[Scope of Claims] 1. After interposing a separator which is wider than the strip-shaped positive and negative electrode plates and has heat-weldable properties between the strip-shaped positive and negative electrode plates, the whole is spirally wound around a winding core, and then this spiral The surplus portion of the separator extending to at least the lower part of the electrode plate group is hardened by heat welding, and the connection lead for either the positive or negative electrode provided at the lower part of the electrode plate group is connected to the hardened surface of the lower part of the separator. Then bend it almost parallel to this towards the center of the electrode plate group so that the lead tip is located on the lower surface of the through hole provided in the center of the hardened surface corresponding to the winding core mark formed at the center of the electrode plate group. A method for manufacturing a cylindrical storage battery characterized by inserting it into a battery case. 2. The separator surplus portion extending to the lower part of the electrode plate group is heat-welded in a donut shape except for the portion corresponding to the winding core trace at the center of the electrode plate group, as set forth in claim 1. Manufacturing method for cylindrical storage batteries. 3. The surplus portion of the separator extending to the lower part of the electrode plate group is bent toward the center of the electrode plate group, and a portion of the connection lead of one electrode facing parallel to the other electrode is partially welded. 2. Method for manufacturing a cylindrical storage battery as described in Section 1.