JPH0646064Y2 - Battery safety valve device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a safety valve device for a battery, and more specifically, it does not have a gas vent hole at the upper end of a cap-like sealing plate.
This is to prevent foreign matter from entering from the outside.

Conventional technology Conventionally, as a safety valve device for this type of battery,
34, Japanese Utility Model Publication No. 59-15398, and the like. That is, to explain with reference to FIG. 4, the sealing plate 1 provided with the safety valve device has the dish plate 2 having the valve hole 2a and the gas vent hole 3a in the center, and is formed by the bent edge portion of the dish plate 2. The cap-shaped terminal plate 3 is crimped, and the flexible thin plate 4 has a peripheral edge sandwiched between the dish plate 2 and the terminal plate 3 and constantly closes the valve hole 2a. A cutting edge 3b that is bent inward and faces the thin plate 4
Further, the sealing plate 1 is hermetically sealed via an insulating packing 7 in an opening of an outer metal case 6 which also serves as a terminal into which the electrode group 5 is inserted. The thin plate 4 is composed of a metal plate, a synthetic resin plate, a synthetic rubber plate, or a composite member thereof.

Then, in the battery, when the internal pressure of the battery rises due to an internal short circuit, external charging, etc. and the internal pressure reaches a predetermined pressure, the thin plate 4 is swollen upward by the gas pressure through the valve hole 2a, and the thin plate 4 becomes a cutting edge. The gas in the battery is hit or damaged by the gas pressure itself, and the gas in the battery is discharged into the atmosphere through the gas vent hole 3a of the cap-shaped terminal plate 3 through the valve hole 2a to prevent the battery from being damaged.

However, in the manufacturing process of this kind of battery, since the terminal plate 3 has a gas vent hole 3a which opens a part of the terminal plate and also serves as the cutting edge 3b, the foreign matter is introduced into the sealing plate for foreign substances through the gas vent hole. And the foreign matter caused the thin plate 4 to be corroded and broken due to pinholes. Further, particularly when constructing a battery of this type, the thin plate 4 is broken by spattering when the positive electrode or the negative electrode of the battery is welded to the dish plate 2 which also serves as a terminal with the connecting lead piece, and the reliability of the safety valve device is deteriorated. Was also a factor.

Problems to be Solved by the Invention In other words, the entry of foreign matter from the outside is due to the fact that a part of the terminal plate 3 is opened and the gas vent hole 3a that also serves as the cutting edge 3b is provided. Not only the gas is discharged from the inside, but also the thin plate 4 is corroded due to the entry of foreign matter from the outside and is broken due to the generation of pinholes, resulting in the deterioration of the reliability most necessary for the safety valve device.

The present invention solves such a problem, and an object thereof is to prevent foreign matter from entering from the outside and prevent deterioration of the thin plate 4.

Means for Solving Problems The present invention has been made to solve the above problems, and a safety valve device provided in a sealing plate portion that closes an opening of an outer metal case of a battery is provided with a valve hole. A cap plate-shaped terminal plate and a cap-shaped terminal plate having a gas plate hole on the peripheral side surface of the cap part, and a flexible thin plate that constantly closes the valve hole by the plate plate and the terminal plate are sandwiched between the cap-shaped terminal plate. The plate has two notches extending from the top surface of the cap portion to the peripheral side surface, the portion between these notches is bent inward of the cap, and an opening is provided at the left and right sides of the notch. The cutting edge provided on the top surface of the terminal plate together with the gas venting hole is a cutting edge projecting into a conical wedge shape with the gas venting hole formed by drawing the central portion of the cap portion.

Therefore, since the cap-shaped terminal plate 3 is provided with the cutting blade having no gas vent hole, foreign matter is prevented from entering from the outside.

Further, when the internal pressure of the battery rises due to an internal short circuit, external charging, etc., and the internal pressure reaches a predetermined pressure, the thin plate 4 swells upward due to gas pressure through a valve hole in the center of the plate, and the thin plate 4 is cut by a cutting blade or It is damaged by the gas pressure itself, and the gas in the battery is released to the outside from a gas vent hole in the shape of a notch recessed in a substantially L-shaped cross section provided in the terminal plate, and damage due to an increase in the battery internal pressure is prevented in advance. Also, when discharging gas, the gas vent hole is a concave recess with an approximately L-shaped cross section, so gas that escapes from the left and right open portions collides and is dispersed, and direct injection does not occur, so it is smooth and safe. Can discharge gas.

Embodiment Next, an embodiment of the present invention will be described with reference to FIG. 1 and FIG. In these drawings, the same symbols as those in FIG. 4 indicate the same things, except that the center of the cap portion of the cap-shaped terminal plate 3 is drawn inward to form a conical wedge without a gas vent hole. The point is that the cutting blade 3b is provided so as to project, the gas vent hole is removed from the top surface of the cap portion, and the gas vent hole 8 is formed in the notched concave portion which is recessed in a substantially L-shaped cross section on the peripheral side surface of the cap portion. Therefore, the cap-shaped terminal plate 3
Since a conical wedge-shaped cutting edge without a gas vent hole is provided in the battery, it is possible to prevent the electrolytic solution, wood chips, and other foreign matter from entering the battery (sealing plate) during the battery manufacturing process. Especially the second
As shown in the figure, when the plate-shaped lead piece 9 is welded to the terminal plate 3, even if the melted metal piece generated at the time of spotting scatters, there is no gas vent hole in the center of the cap part, so that it enters the inside of the sealing plate 1. Then, the thin plate 4 is never destroyed. Further, even if the thin plate 4 swells due to an increase in internal pressure and is damaged by the cutting edge 3b, there is no gas vent hole directly above the valve hole 2a, so direct injection of gas can be prevented.

Next, using the sealing plate equipped with the safety valve device according to the present invention,
Composing a lithium manganese dioxide battery with a capacity of 1200 mAh,
After electrical resistance welding of the plate-shaped lead pieces 9 to these, the safety valve device was disassembled, and the damage of the thin plate 4 was examined. As a result, no abnormality was found. Detailed results are shown in Table-1.

Further, as shown in FIG. 3, the gas vent hole 8 in the shape of a notch recessed into a substantially L-shaped cross section is provided with two cuts from the top surface to the peripheral side surface of the cap portion, and the space between the cuts is substantially L-shaped inside the cap. If the bent portion is bent toward one side and the opening portions 10 are provided on the left and right sides of the bent portion, and the notched concave portion 11 is formed by using the remaining portion of the bending as a gas vent hole, the jetted gases are dispersed due to mutual collision when the internal pressure rises, and the gas is discharged safely and smoothly. Can be done.

As described above, according to the safety valve device of the present invention, a conical wedge-shaped cutting blade having no gas vent hole is provided in the central portion of the terminal plate, and the cross section is substantially L-shaped from the top surface to the peripheral side surface of the cap portion.
By providing a gas vent hole in the shape of a notch recessed in a V shape, foreign matter is prevented from entering during the battery manufacturing process, and the metal piece generated during welding when the plate-shaped lead piece is welded to the cap-shaped terminal plate. The present invention completely prevents foreign matter from entering the inside of the sealing plate through the gas vent holes due to scattering, and can provide a highly reliable safety valve device.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a battery using a sealing plate having a safety valve device according to the present invention, FIG. 2 is a sectional view when a lead piece is welded to a cap-shaped terminal plate, and FIG. FIG. 4 is an enlarged cross-sectional view of the cap-shaped terminal plate of FIG. 4, and FIG. 4 is a cross-sectional view of a main part of a battery showing a conventional example. 1 ... Sealing plate, 2 ... Dish plate, 2a ... Valve hole, 3 ... Cap terminal plate, 3b ... Cutting blade, 4 ... Flexible thin plate, 5 ... Electrode group, 6 ... Metal Case, 7 ... Insulating packing, 8 ...
… Gas vent, 9 …… Lead piece, 11 …… Concave.

Claims (1)

[Scope of utility model registration request] 1. A safety valve device provided on a sealing plate portion for closing an opening of an outer metal case of a battery, the safety valve device including a dish plate having a valve hole in a central portion, a cap-shaped terminal plate,
The cap-shaped terminal plate is provided with a plate-like terminal plate and a flexible thin plate whose peripheral portion is sandwiched between the terminal plates by closing the valve hole at all times.
Notches are formed in the shape of cutouts with a substantially L-shaped cross section in which the slits are cut, the portion between these cuts is bent inward of the cap, and openings are provided on the left and right sides of the cap.
A safety valve device for batteries, which has a conical wedge-shaped cutting edge that does not have a gas vent hole and that protrudes inward from the top surface of the cap part.