JPH0732854U - Cylindrical battery sealing structure with explosion-proof valve - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a sealing structure for a cylindrical battery capable of improving airtightness and venting gas corresponding to a slight change in internal pressure. [Structure] A gasket in which an inner cylinder portion 10 and an outer cylinder portion 20 are integrally connected and molded is used, and an inner peripheral surface 120 of the inner cylinder portion 10 is used.
A groove 80 extending vertically is formed at the same time, and a thin valve portion 90 that divides the groove 80 into upper and lower portions is formed on the way. A cylindrical type in which the current collecting rod is assembled to the gasket 40 by closely adhering and interposing a sealant 100 pre-applied at a predetermined position on the outer surface of the current collecting rod at the joint between the lower end surface of the inner tubular portion 10 and the current collecting rod In the battery sealing structure, the inner cylindrical portion 10 of the gasket 40 at a position below the valve portion 90 is cut out while being inclined downward from the inner peripheral surface 120 toward the outer downward direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cylindrical battery sealing structure having an explosion-proof valve.

[0002]

[Prior art]

 Generally, a sealing structure for a cylindrical battery having an explosion-proof valve has a structure in which an inner cylinder portion and an outer cylinder portion are integrally connected and molded, as disclosed in, for example, Japanese Patent Publication No. 5-11652. Use a plastic gasket with a valve formed on the inner peripheral surface of the cylinder.Insert a collector rod as the positive electrode current collector into the inner cylinder of this gasket to bring the valve into close contact with the collector. The electric pole is attached to the gasket. Then, the outer cylinder portion is fitted to the inner periphery of the opening edge portion of the bottomed cylindrical negative electrode zinc can, and the positive electrode terminal plate is put on the upper end protruding portion of the collector rod to seal the cylindrical battery. I am trying.

The sealing structure of such a cylindrical battery will be described with reference to the gasket plan view of FIG. 5, the gasket cross-sectional view of FIG. 6, the sealing structure cross-sectional view of FIG. 7, and the sealing structure enlarged cross-sectional view of FIG. To do. 5 to 8, 10 is the inner tubular portion of the plastic gasket 40, 20 is the outer tubular portion of the gasket 40, 30 is a connecting portion that connects the inner tubular portion 10 and the outer tubular portion 20, and 50 is a positive electrode collector. A current collecting rod as an electron, 60 is a negative electrode zinc can, and 70 is a positive electrode terminal plate. The gasket 40 has a groove 80 extending vertically on the inner peripheral surface 120 of the inner cylindrical portion 10 that is in pressure contact with the outer periphery of the current collecting rod 50. Has been formed. A thin valve portion 90 having elasticity is formed in the groove 80, and the groove 80 is divided into upper and lower parts on the way. The joint between the lower end surface of the inner cylindrical portion 10 and the current collector rod 50 is sealed by a sealant 100 such as a pitch applied beforehand to the current collector rod 50, and the positive electrode terminal plate is placed on the upper end protruding portion of the current collector rod 50. The lower end of the positive electrode terminal plate 70 is covered with 70, and the upper end face of the inner cylindrical portion 10 is pressed against the inner surface of the positive electrode terminal plate 70. The cylindrical battery is sealed by compressing the outer tubular portion 20 of the gasket 40 from the inner and outer circumferences with the curled opening edge portion of the polar can 60.

In the above configuration, when the internal pressure of the battery becomes excessively high due to, for example, a manganese battery being charged accidentally, the valve portion 90 is flexed and deformed upward by the pressure, and the air chamber 110 is formed between the current collecting rod 50 and the valve rod 90. You can Gas inside the battery is allowed to escape to the outside through the air chamber 110 and an exhaust port (not shown) formed in the positive electrode terminal plate 70. Then, when the internal pressure decreases, the valve portion 90 is elastically closed to reseal the inside of the battery.

[0005]

[Problems to be solved by the device]

 However, in the above-described sealing structure, there is a problem that the air chamber 110 is formed between the valve portion 90, the current collecting rod 50, and the sealant 100 (the groove portion 80), and the airtightness of the battery is impaired. It was That is, as shown in the enlarged cross-sectional views of the main part of the sealing structure of FIGS. 9A to 9C showing the manner of inserting the collector rod 50 into the valve portion 90, the collector 100 to which the sealant 100 has been applied in advance is shown. When the electric rod 50 is tightly inserted into the valve portion 90, the air chamber 110 is formed between the valve portion 90, the current collecting rod 50, and the sealant 100 (the groove portion 80). When such a battery is stored at a high temperature, the air present in the air chamber 110 thermally expands, or when stored for a long period of time, the air in the air chamber 110 repeatedly expands and contracts due to changes in temperature. Therefore, there was a problem that the sealing agent 100 was punctured and the airtightness of the battery was impaired.

In addition, since the air existing in the air chamber 110 absorbs the fluctuation of the internal pressure, the hinge characteristic of the valve section 90 is deteriorated, and it becomes impossible to vent gas corresponding to the slight fluctuation of the internal pressure. there were.

The present invention solves the above problems, and an object thereof is to provide a sealing structure for a cylindrical battery capable of improving airtightness and performing degassing in response to a slight change in internal pressure. is there.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention uses a gasket in which an inner tubular portion and an outer tubular portion are integrally connected and molded, and a groove extending vertically is formed on the inner peripheral surface of the inner tubular portion, and A thin valve part is formed on the way to divide the groove into upper and lower parts, and a current collecting rod as a positive electrode current collector is inserted into the inner cylindrical part so that the valve part is brought into close contact with the current collecting rod and the outer surface of the current collecting rod is attached. Assemble the current collector rod to the gasket by interposing a sealant previously applied at a predetermined position at the joint between the lower end surface of the inner cylinder and the current collector rod, and attach it to the inner periphery of the opening edge of the negative electrode can. The outer cylinder part is fitted, the positive electrode terminal plate is covered on the upper end protruding part of the current collecting rod, and the outer peripheral part of the positive electrode terminal plate and the opening edge part of the negative electrode can form the gasket outer cylinder part. In the cylindrical battery sealing structure that is compressed from the inner and outer circumferences, the position below the valve section It said inner cylindrical portion of definitive the gasket from the inner peripheral surface is become by notched inclined I suited out below.

[0009]

[Action]

 According to the present invention having the above-mentioned structure, since the inner cylindrical portion of the gasket at the lower position of the valve portion is cut out by inclining from the inner peripheral surface toward the outer downward direction, the current collecting rod is tightly inserted into the valve portion. In doing so, the air between the valve, current collector and sealant will escape below the gasket along the sloping notch, ensuring that the sealant will be able to reach the valve and collector. There is no close contact and no air is trapped between the valve, current collector and sealant.

[0010]

【Example】

 Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Since the basic structure of the cylindrical battery having the sealing structure according to the present invention is common to the conventional sealing structure shown in FIGS. 5 to 8 above, the common parts are designated by the same reference numerals. Therefore, detailed description is omitted.

In this embodiment, as shown in the cross-sectional view of the gasket 40 of FIG. 1, the inner cylinder portion 10 located below the valve portion 90 of the gasket 40 is directed outward from the inner peripheral surface 120. The cutout surface 130 is shaped so as to form a part of a conical surface.

In the above structure, when the collector rod 50 is tightly inserted into the valve portion 90, as shown in the enlarged cross-sectional views of the main part of the sealing structure shown in FIGS. When the part 90 and the current collector 50 are bonded, the air existing between the valve part 90, the current collector 50 and the sealant 100 escapes below the gasket 40 along the inclined cutout surface 130. Therefore, the air is not trapped, that is, the air is not trapped between the valve portion 90, the current collecting rod 50, and the sealant 100. The cylindrical battery (R03 type) using the sealing structure manufactured in this way was measured for the occurrence rate of air entrapment and the incidence rate of open circuit voltage drop products due to air intrusion, and the results shown in the table below were obtained. Was obtained.

[0014]

[Table 1]

[Table 2]

[Table 3]

[Table 4] Table 1 shows the occurrence rate of air entrapment during assembly. In the conventional product, 32 out of 40 air entrapments occurred, whereas in the present embodiment, one entrapment occurred. It has only occurred. Moreover, the amount of air hugged was extremely small for the one in which this air hugging occurred. In addition, Table 2 shows the incidence of air-entrapped products and the incidence of products with open circuit voltage drop due to air intrusion after 3 years of storage at room temperature, compared with some of the conventional products. However, the thing of this Example did not occur. The same is true for the same occurrence rate after 1 month at room temperature storage after 3 months of 80 ° C storage in Table 3 and 1 year after room temperature storage after 100 cycle test (-20 ° C 1 hour / 70 ° C 1 hour) in Table 4. That is, it is possible to prevent the entrapped air from repeating thermal expansion or expansion and contraction to open a hole in the sealant 100 to impair the airtightness. From the above results, it was confirmed that the sealing structure of the present invention has extremely improved airtightness and reliability.

Further, it is possible to prevent the air chamber 110 from being generated and to absorb the fluctuation of the internal pressure to deteriorate the hinge characteristic of the thin valve portion 90, and it is possible to perform the degassing corresponding to the slight fluctuation of the internal pressure.

Although the present invention has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. For example, as shown in FIG. 2, the cutout surface 130 may be cut out so as to form a part of the curved surface of the dome, or as shown in FIG. It is also possible to have a shape in which a straight cylindrical portion is connected to a tapered surface that forms a part of the surface, and the same effect as that of the embodiment shown in FIG. 1 can be obtained.

[0017]

[Effect of device]

 As described above in detail, according to the present invention, since the inner cylinder portion of the gasket at the lower position of the valve portion is cut out by inclining from the inner peripheral surface toward the outer downward direction, the collector rod is When the valve is tightly inserted into the valve part, the air between the valve part, the current collector and the sealant escapes below the gasket along the inclined cutout surface, so that the sealant will not contact the valve and the current collector. The air is not trapped between the valve, the collector rod and the sealant.

Therefore, it is possible to prevent a hole from being formed in the sealant due to the thermal expansion of the trapped air due to the high temperature storage or the repeated expansion and contraction of the air due to the temperature change during the long-term storage, and to prevent the sealing agent from having a hole. It is possible to improve the airtightness and reliability of the sealing structure of the rechargeable battery.

Further, since there is no air to be trapped, fluctuations in the internal pressure of the battery are not absorbed, so that the hinge characteristics of the valve portion can be improved as much as possible, so that a small internal pressure It is possible to degas in response to fluctuations.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a gasket according to the present invention.

FIG. 2 is an enlarged cross-sectional view of another type of gasket according to the present invention.

FIG. 3 is an enlarged cross-sectional view of a gasket according to another embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of a main part of the sealing structure according to the present invention, in which (a) to (c) show how the current collecting rod is inserted into the gasket.

FIG. 5 is a plan view of a conventional gasket.

6 is a cross-sectional view of the conventional gasket of FIG. 5 taken along line VI-VI.

FIG. 7 is a cross-sectional view of a conventional sealing structure.

FIG. 8 is an enlarged cross-sectional view of a conventional sealing structure.

FIG. 9 is an enlarged vertical sectional view of a main part of a conventional sealing structure,
(A)-(c) has shown the mode which inserts a collector into a gasket.

[Explanation of symbols]

 10 Inner Cylinder (of Gasket 40) 20 Outer Cylinder (of Gasket 40) 30 Connection (of Gasket 40) 40 Gasket 50 Positive Electrode Current Collector 60 Negative Zinc Can 70 Positive Terminal Plate 80 Groove (Inner Cylinder 10) 90 Thin valve part 100 Sealant 110 Air chamber 120 Inner peripheral surface (of inner cylinder part 10) 130 Notched surface

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Mitsuo Murakoshi 5-11-3 Shimbashi, Minato-ku, Tokyo Fuji Electric Chemical Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A gasket, in which an inner tubular portion and an outer tubular portion are integrally connected and molded, is used to form a vertically extending groove on an inner peripheral surface of the inner tubular portion and partition the groove up and down on the way. A thin valve portion is formed, and a current collector rod as a positive electrode current collector is inserted into the inner cylinder portion to bring the valve portion into close contact with the current collector rod and a seal previously applied to a predetermined position on the outer surface of the current collector rod. The current collector is assembled to the gasket by interposing the agent at the joint between the lower end surface of the inner cylinder and the current collector, and the outer cylinder is fitted to the inner periphery of the opening edge of the negative electrode can. Cover the positive electrode terminal plate on the upper end protruding portion of the current collector,
In a sealing structure for a cylindrical battery in which the gasket outer cylinder portion is compressed from the inner and outer circumferences by the outer peripheral edge portion of the positive electrode terminal plate and the opening edge portion of the negative electrode can, in the gasket below the valve portion, A cylindrical battery sealing structure, characterized in that the inner cylindrical portion is cut out so as to be inclined downward from the inner peripheral surface toward the outside.