JPS6246953B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a spiral electrode group typified by a nickel-cadmium storage battery, and includes a band-shaped separator that covers both the upper and lower surfaces of one of the band-shaped positive and negative electrode plates and isolates it from the counter electrode. A high-performance spiral electrode group that prevents misalignment of the separator by thermally welding the winding start and winding ends of the winding, and enables efficient spiral winding work to prevent short circuits between electrode plates. The purpose is to provide

A typical method of constructing a spiral electrode group is to cover both the top and bottom surfaces of either the positive or negative electrode plate with two strip-shaped separators cut longer than the electrode plate length, and to extend forward from the tip of the electrode plate. The excess portion of the extended separator is used as the winding start point and wound around the core (mandrel), and the mandrel is wound to swirl the entire separator, the electrode plate covered with this separator, and the other electrode plate on the separator. It is wound in a shape.
However, when using pre-cut strip separators like this, it is not possible to adequately align and width the separators at the beginning of winding, resulting in the separators winding misaligned, exposing the ends of the electrode plates, and causing internal short circuits. It had the disadvantage that it frequently occurred.

Therefore, in order to solve this problem, as shown in FIG. 1, the winding start portions 2 of the two band-shaped separators 1a and 1b are trimmed in advance, and after these portions are integrated by welding or gluing, One strip-shaped electrode plate, for example, the anode plate 3, is sandwiched and covered, and the other cathode plate 4 is placed along the outside of the separator 1b to maintain a predetermined length, and then the strip-shaped separator 1
A method has been proposed in which a portion 5 rearward of the ends of the electrode plates 3 of a and 1b is cut with a cutting blade and then wound with a winding core 6. In this case, since the ends of the separators 1a and 1b are fixed to each other near the winding start part 2 held by the winding core 6, no displacement occurs and the cathode plate 4 is reliably protected as shown in FIG. The separators 1a and 1b are positioned as shown in FIG. However, the rear ends of separators 1a and 1b have been cut and are in a free state, and furthermore, due to the difference in the radius of curvature and expansion and contraction of separators 1a and 1b when rotating core 6 in the direction of the arrow to form a spiral shape. After the part -' in Figure 1, the separator is misaligned and an exposed part 7 of the electrode plate is not covered by the separator, which causes an internal short circuit after it is assembled into the battery container as a spiral electrode group. Something happened. Therefore, it is necessary to correct the misalignment, and since the separators 1a and 1b are also cut using cutting blades, there is a problem that the deterioration of the cutting blades makes it difficult to cut to a fixed size and the cut edges become rough. This required frequent replacement and resharpening of the blade, and there was no improvement in workability.

The present invention solves the problems of the conventional spiral electrode groups mainly caused by the misalignment of the separators, and is characterized by the fact that one of the strip-shaped electrode plates is sandwiched between the separators and covered. The winding start portions 2 of the two band-shaped separators are heat-welded in advance to integrate them, and the other band-shaped electrode plate is spirally wound along the separator, and just before the winding ends, the separator behind the end of the electrode plate is The purpose is to fuse and cut the mutually contacting parts with heated cutting blades to eliminate misalignment and fraying of the fibers at the ends of the separator.

An embodiment of the present invention will be described below with reference to FIG.
In the figure, reference numerals 1a and 1b indicate long strip-shaped separators that are wound in rolls, and are made of a heat-meltable material such as a nonwoven fabric of polyamide fibers or polypropylene fibers. The winding start portion 2 of the separator, which is first held together with the cathode plate tip by the winding core 6, is previously melted into a band shape and integrated by heat treatment.

Then, without cutting the two band-shaped separators 1a, 1b, the winding core 6 is rotated as before to wind the separators 1a, 1b and the electrode plates 3, 4 in a spiral shape.

When the spiral electrode group 8 is wound without cutting the separators in this way, even if there are differences in the radius of curvature and expansion/contraction due to the difference between the inside and outside of the two strip-shaped separators, the separators are restrained in the rolled state and are free. Since the separator does not move, no displacement of the separator occurs.

Then, just before the end of the spiral winding, a heated cutting blade 9 such as a knife is applied to the portion 5 where the separators 1a and 1b are in contact with each other behind the end of the electrode plate 4 to melt it. No displacement or fraying occurs at the ends of the separators 1a, 1b covering the plate 3, and an electrode group can be obtained in which the separators reliably isolate the strip-shaped electrode plates.

At the same time, the remaining parts of the separator cut by the heated cutting blade 9 are also thermally welded and integrated, so that they can similarly be used as the winding start part 2 when forming the next spiral electrode group. . Therefore, from now on, the end welding process of the separator and the welding process at the beginning of the separator winding for the next electrode group can be performed at the same time, and the winding work when forming the spiral electrode group can be done efficiently, and the position of the separator can be adjusted. It is also possible to sufficiently suppress the occurrence of internal short circuits due to mutual contact between exposed electrode plates due to misalignment.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the manufacturing process of the spiral electrode group so far, Fig. 2 is a schematic cross-sectional view taken along the -' line in Fig. 1, and Fig. 3 is a cross-sectional view taken along the -' line in Fig. 1. The schematic diagram, FIG. 4, is a diagram showing a manufacturing process of a spiral electrode group in an embodiment of the present invention. 1a, 1b...thermofusible band-shaped separator,
2... Winding start portion, 3... Anode plate, 4... Cathode plate, 5... Separator cutting portion, 6... Winding core, 9... Heated cutting blade.

Claims (1)

[Claims] 1. In a method of spirally winding a band-shaped anode plate and a cathode plate with a band-shaped separator interposed between them, both the upper and lower surfaces of either the positive or negative band-shaped electrode are covered with heat-meltable resin fibers. It is covered with two strip-shaped separators consisting of two strips of separator, and is wrapped spirally with the other electrode plate, and just before the end of winding, the part where the strip-shaped separators come in contact with each other behind the end of the electrode plate is fused with a heated cutting blade. A method for manufacturing a spiral electrode group, characterized in that the ends of the separators are simultaneously welded together, and the winding start ends of two separator strips covering the next electrode plate are welded at the same time.