JPS5910537B2 - 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 treatment 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

For cylindrical storage batteries with a spiral plate group, such as sealed nickel-cadmium storage batteries, the NR-D and NR-F types, which have a large battery capacity, have a spiral plate group and Two connection leads are provided at the upper and lower ends, and one lead provided at the bottom is often spot welded to the inner bottom surface of the battery case made of nickel-plated steel.

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 two on the cathode side, One of the connecting leads 4 and 4' is passed through the center hole 1' of the insulating plate 1, and the other is extended to the outside from the outside of the insulating plate, thereby insulating the lower end of the electrode plate group. Ta.

Figure 6 and Figure T show the electrode plate group to which this insulating plate is applied, and for ease of understanding, the actual electrode plate group is upside down.
The lower end of the electrode plate group is shown in the figure. 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 and the end of one lead 4' may not extend outward from the center 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, and there is a problem that the position of the insulating plate must be inspected and adjusted each time, making the storage battery assembly process complicated and time-consuming.

The present invention provides a spiral electrode group by interposing a synthetic resin separator wider than the width of the electrode plates between the electrode plates and winding the entire separator, and extending at least to the lower part of the electrode plate group. By applying thermoplastic synthetic resin to the excess part of the separator and making this part a hard insulating part, a kind of insulating isolation part that is integrated with the electrode plate group is formed at the bottom of the electrode plate group. The connecting lead for either the positive or negative pole extending downward from the bottom edge of the plate group can be easily pulled out to the center of the bottom of the plate group, making it easier to assemble a cylindrical storage battery and automatically assembling it. It provides a manufacturing method.

Hereinafter, the embodiments of the present invention will be explained as well as the conventional examples.
Cadmium storage batteries will be explained. First, as in the past, a separator 3 made of a synthetic resin, for example, polypropylene non-woven fabric or polyamide non-woven fabric, which is wider than the band-shaped anode plate and cathode plate, is interposed between the band-shaped anode plate and the cathode plate, and the whole is spirally wound. to form electrode group 2. As a result, an excess portion 3' of the separator extends from at least one end, usually both ends, of the electrode plate group 2. By melting and applying a thermoplastic synthetic resin, such as polypropylene, to one surplus part 3/ of this separator, this surplus part 3' hardens as the applied resin hardens, forming a donut-shaped hard part. It becomes the conversion part 5.

At this time, the following points should be noted: (a) After applying the thermoplastic resin to the excess portion 3' of the separator and hardening it, make sure that the electrode plate is not exposed beyond this point. ) Resin does not adhere to the electrode plate when applying the resin; (c) There is a welding electrode necessary for spot welding the leads 4 and 4' to the inner bottom of the case in the center of the hardened part 5 where the resin is hardened. The hole 5' must be large enough for the rod to pass through, for example, 5 to 7 holes. Figure 1 shows the electrode plate group constructed in this way, with the top and bottom positions reversed for ease of understanding. If it is inserted into the battery case in the normal state, the hardened part 5 is integrated with the electrode plate group and will not shift when inserted into the case, and the connection leads 4, 4 as shown in FIG. ′ is inward (
By being bent toward the center of the electrode plate group, the tip thereof comes to be located on the lower surface of the hole 5' present in the center of the hardened portion 5.

For this reason, spot welding between the overlapping leads 4 and 4' and the inner bottom of the battery case after inserting the electrode plate group into the battery case will result in a space remaining as a core trace in the center of the electrode plate group and a hardened part. By inserting the welding electrode rod through the hole 5' of 5, the lead and the inner bottom of the case can be integrated under pressure while the lower part of the electrode plate group 2 is sufficiently insulated from the battery case.
Spot welding of both can be easily performed without any problems, and automation is also possible. FIG. 3 is a perspective view showing a state in which such a donut-shaped hardened portion 5 is formed on the entire lower end surface of the electrode plate group.

In addition, as shown in Fig. 4, when the electrode plate group is inserted into the case and the leads 4' are bent inward, resin is partially applied to the corresponding part to form a rectangular hard shape. conversion part 6
Even if it is formed, insulation between the electrode plate group and the battery case can be ensured. Therefore, short circuits between the electrode plates at the bottom of the electrode 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 welding of the lead ends to the inner bottom of the battery case is also possible. This can be easily done in the same way as shown in FIGS.
Of course, thermoplastic resin is melted and applied to the excess part of the separator, and the hardened part is cooled and solidified to insulate the inner bottom of the battery case and the lower part of the electrode plate group. However, it is preferable to treat the excess portion of the separator at the upper end of the electrode plate group in the same manner, as this will further ensure the restraint of the electrode plate group and facilitate 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 donut-shaped insulating plate does not shift relative to the electrode plate group as in the conventional example. The battery can be inserted, and the connection lead provided at the bottom of the electrode plate group can be pulled out to correspond to the hole in the hardened part located at the center of the bottom of the electrode plate group, making it easy to weld this lead to the inner bottom of the battery case. Therefore, the battery assembly process can be automated with good workability.

[Brief explanation of the drawing]

Fig. 1 is a side view of a plate group constructed by an embodiment of the manufacturing method of the present invention, Fig. 2 is a side view of the same plate group with its leads bent toward the center of the plate group, and Fig. 3 4 is a perspective view of an electrode plate group according to another embodiment, FIG. 5 is a perspective view showing a conventional donut-shaped insulating plate, and FIG. 6 is a side view of a conventional electrode plate group. FIG. 7 is a perspective view thereof. 2...Spiral plate group, 3ζ...Separator surplus part, 4,47...Connection lead, 5,6
...Hardened portion formed by hardening of thermoplastic synthetic resin, 5'... Hole.

Claims (1)

[Scope of Claims] 1 After interposing a synthetic resin separator wider than the strip-shaped positive and negative electrode plates and winding the whole in a spiral shape around a winding core, this spiral pole is A thermoplastic synthetic resin is applied to the excess part of the separator extending at least to the bottom of the plate group to make this part a hardened part, and a connection lead for either the positive or negative pole provided at the bottom of the plate group is Bend the battery substantially parallel to the hardened portion toward the center of the electrode plate group, and bend the battery so that its tip is located on the lower surface of the through hole formed in the hardened portion, corresponding to the winding core trace at the center of the electrode plate group. A method for manufacturing a cylindrical storage battery characterized by being inserted into a case. 2 The excess portion of the separator extending below the spiral electrode plate group is
2. The method of manufacturing a cylindrical storage battery according to claim 1, wherein the thermoplastic synthetic resin is applied in a donut shape except for the center winding core trace. 3 A patent claim in which the excess portion of the separator extending to the bottom of the electrode plate group is coated with a thermoplastic synthetic resin on a portion that corresponds to the connecting lead of one electrode when it is bent toward the center of the electrode plate group. A method for manufacturing a cylindrical storage battery according to item 1.