JPS6341190B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cylindrical battery, and more particularly to a method for manufacturing a cylindrical battery in which the lower end opening of a cylindrical separator with open ends is closed with a heat-melting substance.

FIG. 1 shows an example of a conventional cylindrical battery, in which a cathode mixture 2, a separator 3, and an anode mixture 4 are placed coaxially with each other and loaded into a cylindrical anode can 1. ing. Incidentally, in this type of battery, the separator 3 is formed into a cylindrical shape with both ends open. This is because when folding and forming a cylindrical piece using a single separator piece, it is much easier to process a separator with open ends than one with a bottom, and it is also more accurate in shape and dimension. This is because it is easy to obtain a uniform product. However, since both ends of the separator 3 are open, the lower end, that is, the opening on the side that contacts the central inner bottom surface 1a of the anode can 1, needs to be closed by some means. For this purpose, in the past, as shown in FIG.
It was common practice to fit into a.
The fitting of the closing member 5 is as shown in FIG.
This was done by inserting the separator 3 into the anode can 1 and then inserting the closing member 5, which was previously formed to match the inner diameter of the separator 3. However, in order to use such a closing member 5 to close the lower end opening 3a of the separator 3 without impairing the characteristics of the battery, the closing member 5 must have a sufficient thickness as shown in FIG. I needed to make it bigger. Otherwise, problems may occur such as the formation of precipitates that form internal short circuits or leak paths in the gap between the separator 3 and the closing member 5. However, if the thickness of the closing member 5 is increased, another problem arises in that the filling volume of the cathode mixture 2 decreases, resulting in a decrease in discharge capacity. Furthermore, since the closing member 5 is in mechanical contact with the separator 3 by simply being fitted into it, its stability cannot necessarily be said to be good, and its characteristics may deteriorate when subjected to mechanical impact. It becomes more susceptible to deterioration. Therefore, as proposed by the applicant, after inserting a cylindrical separator 3 into the central lumen 4a of the anode mixture 4, as shown in FIG. An electrically insulating heat-fusible substance 6 is injected into the central inner bottom surface 1a of the anode can 1, which is annularly surrounded by the edge of the opening 3a, and a layered portion 7 formed of the heat-fusible substance 6 is injected. Therefore, the lower end opening 3
There is a method for manufacturing a cylindrical battery in which a is closed. Therefore, according to this manufacturing method, the lower end opening 3a can be easily formed without requiring complicated steps.
This ensures that it is completely closed and is sufficiently strong against mechanical shock.

However, in this manufacturing method, simply injecting the heat-fusible substance 6 into the central inner bottom surface 1a of the anode can 1 results in the layered portion 7 being thinner than the closing member 5. Even so, the substance 6 does not spread well and a relatively large amount of the heat-fusible substance 6 is required. Therefore, the layered portion 7
There was a problem in that the thickness of the cathode mixture 2 became relatively thick, resulting in a decrease in the filling volume of the cathode mixture 2 as described above.

In view of such conventional problems, the present invention develops the injected thermofusible material under pressure toward the inner bottom surface of the center of the battery can (anode can) while the injected thermofusible material is in a flowable state. By performing a pressurized expansion process to close the lower end opening of the cylindrical separator,
A cylindrical battery that can reliably close the lower end opening, reduce the amount of heat-melting material injected, and increase the amount of mixture filled into the cylindrical separator to increase discharge capacity. The present invention provides a method for manufacturing.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings. Incidentally, in explaining this embodiment, the same reference numerals are attached to the same or corresponding parts as those in the conventional example.

That is, FIGS. 4A, B, C, and D show an example of the method for manufacturing a cylindrical battery according to the present invention. To describe a manganese battery, the battery can is an anode can.), and this anode can 1
The anode mixture 4 with a central lumen 4a formed therein is closely loaded, and a cylindrical separator 3 with both ends open is inserted into the central lumen 4a. The anode mixture 4 has manganese dioxide as its main ingredient, for example, and is molded into an annular shape by previously forming the central lumen 4a. Further, the separator 3 is impregnated with an alkaline electrolyte. Further, inside this separator 3, after closing the lower end opening 3a with a heat-fusible substance 6, which will be described later, a cathode mixture containing, for example, zinc as a main ingredient is filled, although not shown. . Here, in the present invention, when the cylindrical separator 3 is inserted into the central lumen 4a of the anode mixture 4, electrically insulating heat is applied from the inside of the separator 3 to the central inner bottom surface 1a of the anode can 1. The meltable substance 6 is injected in a fluid state (Figure A). At this time, the heat-fusible substance 6 is easily injected from the tip of the injection tube 10 inserted into the separator 3. By the way, the heat-melting substance 6 is preferably a synthetic resin, particularly a mixture of low-molecular-weight polyethylene and low-molecular-weight polypropylene, and in actual production, this mixture is heated to about 200°C and 0.8 g
Inject about 1.0g. Then, the injection pipe 1
When 0 is extracted from the separator 3, the injected heat-fusible substance 6 remains in a raised state on the central inner bottom surface 1a of the anode can 1 (Figure B).
In this state, the heat-fusible substance 6 is transferred to the separator 3.
It does not contact the entire periphery of the lower end opening 3a. Next, while the heat-fusible substance 6 is in a flowable state, the heat-fusible substance 6 is poured onto the central inner bottom surface 1a of the anode can 1.
A pressurizing and expanding step is performed in which the separator 3 is pressurized and expanded toward the end to close the lower end opening 3a of the separator 3 (Figure C).
In this embodiment, this pressurization and expansion step is performed by the pressure of gas injected toward the central inner bottom surface 1a. That is, separator 3
The nozzle 11 is inserted through the upper end opening 3b, air is jetted downward from the nozzle 11, and the heat-fusible substance 6 on the central inner bottom surface 1a is stretched by the pressure of the jetted air at this time. The heat-fusible substance 6 is brought into contact with the inner periphery of the lower end opening 3a of the separator 3, and a thin layered portion 7a is formed.
In addition, at this time, it is necessary to provide a gap between the nozzle 11 and the inside of the separator 3 at least enough to allow the injected air to be discharged. and,
By cooling and solidifying the heat-fusible substance 6 that has become the layered portion 7a, the lower end opening 3a of the separator 3 is reliably closed (Fig. D).

According to the manufacturing method described above, the thin layered portion 7a can be formed by performing the pressurized development step, thereby increasing the filling volume of the cathode mixture 2 and increasing the discharge capacity. be able to. Moreover, the lower end opening 3a of the separator 3 is located at the layered portion 7.
It is reliably closed by a.

FIG. 5 shows another embodiment in which the pressurizing and expanding process is carried out by a pressurizing rod 12 that is inserted from above the separator 3 and presses it toward the central inner bottom surface 1a of the anode can 1. . That is, the pressure rod 12 is formed to have approximately the same diameter as the inner diameter of the separator 3, and its lower end surface 12a is formed into a flat surface perpendicular to the axial direction. The heat-fusible substance 6 is inserted through the opening 3b and bulges on the central inner bottom surface 1a of the anode can 1.
is pressed with the lower end surface 12a.

Even if the pressure development process is performed using the pressure rod 12 in this way, the same effect as in the embodiment shown in FIG.
The lower end opening 3a can be closed by forming the thin layered portion 7a. It goes without saying that the lower end surface 12a of the pressure rod 12 is designed so that it can be easily peeled off from the heat-fusible substance 6.

As explained above, in the present invention, a cathode mixture, an anode mixture, and a cylindrical separator which separates these electrode mixtures and is open at both ends are arranged coaxially with each other and loaded into a cylindrical battery can. , a method for manufacturing a cylindrical battery in which a lower end opening of the cylindrical separator is closed with an insulating material, the cylindrical separator having an inner part formed in the center of a mixture disposed outside the separator; After inserting it into the cavity, an electrically insulating heat-fusible substance is injected in a fluid state from inside the separator to the inner bottom surface of the center of the battery can, and then, while the heat-fusible substance is in a flowable state, this Since the pressurized development process is performed in which the heat-fusible material is spread under pressure toward the central inner bottom surface of the cylindrical separator to close the bottom opening of the cylindrical separator, the heat-fusible material forms a thin layer and forms the bottom opening of the cylindrical separator. occlude. Therefore, an excellent effect is achieved in that the amount of mixture filled into the separator can be increased and the discharge capacity can be increased.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional cylindrical battery.
Figure 2 is a sectional view showing part of the assembly process, Figure 3 is a sectional view showing a part of the assembly process.
The figure is a sectional view showing a part of the assembly process of another example of a conventional cylindrical battery, and FIGS. 4A, B, C, and D show an embodiment of the method for manufacturing the main parts of the cylindrical battery of the present invention. cross section,
FIG. 5 shows another embodiment of the present invention and is a sectional view corresponding to FIG. 4C. 1...Anode can (battery can), 1a...Central inner bottom surface,
2...Cathode mixture, 3...Separator, 3a...Lower end opening, 4...Anode mixture, 4a...Central lumen part,
6...Thermofusible substance, 10...Injection pipe, 11...
Nozzle, 12...pressure rod.

Claims (1)

[Scope of Claims] 1 A cathode mixture, an anode mixture, and a cylindrical separator which separates these electrode mixtures and are open at both ends are arranged coaxially with each other and loaded into a cylindrical battery can, A method for manufacturing a cylindrical battery in which a lower end opening of a cylindrical separator is closed with an insulating material, the cylindrical separator having a lumen formed in the center of a mixture disposed outside the separator. Then, an electrically insulating heat-melting substance is injected in a fluid state from the inside of the separator into the central inner bottom surface of the battery can, and then, while the heat-melting substance is in a flowable state, this heat-melting substance is injected into the battery case. 1. A method for manufacturing a cylindrical battery, comprising: performing a pressurizing and expanding step in which a substance is pressurized and expanded toward the central inner bottom surface of a battery can to close a lower end opening of the cylindrical separator. 2. The method for manufacturing a cylindrical battery according to claim 1, wherein the pressurized expansion step is performed using the pressure of gas injected toward the central inner bottom surface of the battery can. 3. Manufacture of the cylindrical battery according to claim 1, characterized in that the pressurizing and expanding step is carried out using a pressurizing rod that is inserted from above the separator and presses it toward the central inner bottom surface of the battery can. Method.