JPS60157156A - Exhaust valve for lead storage battery - Google Patents

Abstract

PURPOSE:To enable the cut of an elastic plate to open when the internal pressure of a lead storage battery is high and to close when the internal pressure is low by causing the outer area of the elastic plate to more easily expand and deform than its inner area. CONSTITUTION:An exhaustion valve for a negative electrode absorption type sealed battery is formed by interposing an elastic plate 1 made of rubber or the like and having a pin-hole or cut 2 between a lower frame 3, which has a hole 3' having a smaller diameter and opening into the internal space of the battery, and an upper frame 5, which has a larger diameter and opening into external air. Due to the difference in diameter between the openings 3' and 5', the outer area of the elastic plate 1 easily expands and deforms and the inner area hardly expands and deforms, Therefore, the cut 2 opens when the internal pressure of the battery is high and the cut 2 is closed when the internal pressure is low. As a result, external air is prevented from permeating into the battery, thereby improving its reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the structure of an exhaust valve for a sealed lead-acid battery.

In a negative electrode absorption type sealed battery in which oxygen gas generated from the positive electrode plate is reacted with and absorbed by the negative electrode plate, it is essential that outside air, that is, air, is not allowed to enter the battery. This is because the negative electrode plate is oxidized and discharged by oxygen gas in the air. Therefore, there is a need for a reliable exhaust valve that has the function of releasing the gas inside the battery to the outside and preventing outside air from entering the battery.

Various types of exhaust valves of this type have been proposed and put into practical use. Recently, there has been a strong demand for smaller sealed batteries, and the need for small and reliable exhaust valves has increased.

A simple valve that meets this requirement has been proposed by having a pinhole or cut in an elastic body. This is because when the inside of the battery is pressurized, the elastic body expands and deforms to the outside, opening pinholes and cuts.
Even when the inside of the battery is in a reduced pressure state, the elastic body opens in the same way, so there is a drawback that outside air can enter the inside of the battery.

The present invention provides an exhaust valve that is small in size and prevents outside air from entering the battery even if the interior of the battery is in a reduced pressure state. The gist of this method is to airtightly hold a plate-like elastic body with pinholes or cuts that open when it expands or deforms beyond a certain limit on a support, and to wrap the periphery of the plate-like elastic body from the inside to the outside. The aim is to create a structure that is easy to expand and deform.

Hereinafter, the present invention will be explained with reference to FIG. 1 showing one embodiment thereof. Reference numeral 1 denotes a plate-shaped elastic body made of synthetic rubber, natural rubber, flexible plastic, etc., and the shape thereof is circular, square, hexagonal, etc. . 2 is a pinhole in the plate-like elastic body 1, but it may also be a + or - cut. Reference numeral 3 denotes a lower frame body supporting the plate-like elastic body 1, and has a mounting portion 4 for attaching to the battery cover, which is attached by screwing, fitting, pressure bonding, adhesion, or the like. Reference numeral 5 denotes an upper frame body that presses down the plate-shaped elastic body 1, and is integrated with the lower frame body 3 through a portion indicated by the reference numeral 6. 3' is an opening in the lower frame 3, which is connected to the space inside the battery, and is the initial path for the gas inside the battery. Reference numeral 5' denotes a frontage of the upper frame 5, which is a space in which the flexible plate-shaped elastic body 1 can expand and deform outward, and also serves as a path for gas inside the battery discharged from the pinholes and cuts 2. The opening 3' of the lower frame 3 is smaller than the opening 5' of the upper frame 5, making it difficult for the flexible elastic plate 1 to deform into the battery.

Since the exhaust valve according to the present invention has the structure as described above,
When the pressure inside the battery increases, the flexible plate-like elastic body 1 expands and deforms outward, creating a pinhole or cut 2.
opens and discharges the gas inside. However, even if the pressure inside the battery is reduced, the opening 3' of the lower frame 3 is small, so the flexible plate-like elastic body 1 hardly deforms, and therefore the pinhole or cut 2 does not open, so the outside air Prevent it from entering the battery. In addition, by appropriately selecting the size and shape of the opening 3', when the pressure inside the battery becomes extremely low, a pinhole or cut 2 will open, which will alleviate the reduced pressure and prevent damage to the battery case. It can be prevented.

One pinhole is made in a Butil rubber sheet with a thickness of 0.5n+m.
For an exhaust valve in which the plate-like elastic bodies 1 are opened, the opening 3' of the lower frame 3 is circular with a diameter of 2 ml1, and the opening 5' of the upper frame 5 is circular with a diameter of 4I, the pressure difference between the inside and outside is determined. The relationship between this and the amount of gas flowing in and out is not shown in Figure 2. In this figure, negative pressure means reduced pressure inside, and negative gas amount means intrusion into the inside from the outside. As is clear from the figure, when the inside is pressurized, the valve operates at about 0.2 atm, but when the pressure is reduced, the external gas has to reach about 0.6 atm before the outside gas enters the inside. do not.

In the embodiment of the present invention shown in FIG. 1, the flexible plate-shaped elastic body 1 is supported by the lower frame 3 having a mounting part for the battery lid. The elastic body 1 may be supported and the lower frame body 3 may be omitted.

It is important that the gas inside the battery moves only through the pinholes and cuts 2 in the elastic plate 1, and the gas inside the battery moves from between the elastic plate 1 and the lower frame 3 or the upper frame 5. No gas or outside air should be allowed to enter or exit.

In order to make it difficult for the flexible plate-like elastic body 1 to expand and deform inward, as shown in the figure, the area of the opening of the frame is made smaller than that of the upper frame. In addition, a grid-like or net-like support may be provided on the lower surface of the plate-like elastic body 1 so as not to block the pinholes or the cuts 2.

As is clear from the above, the exhaust valve according to the present invention has excellent advantages such as being small, preventing outside air from entering the battery even when the battery is under reduced pressure, and being highly reliable. be.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a main part showing an embodiment of an exhaust valve for a lead-acid battery according to the present invention, and FIG. 2 is a characteristic diagram showing the relationship between the pressure difference between the inside and outside of the exhaust valve for a lead-acid battery according to the present invention and the exhaust gas m. It is. DESCRIPTION OF SYMBOLS 1... Plate-shaped elastic body, 2... Pinhole or cut, 3... Lower frame body, 3'... Frontage part, 5... Upper frame body, 5'... Opening part

Claims (1)

[Claims] (1) A supporting part is used to airtightly hold the periphery of a plate-shaped elastic body that has pinholes or cuts that open when expanded or deformed beyond a certain limit, and the plate-shaped elastic body is held on the outside more than on the inside. Exhaust valve for lead-acid batteries with a structure that easily expands and deforms. (2) The exhaust valve for a lead-acid battery according to claim (1), which has a support portion in which an outer opening in which the plate-like elastic body can expand and deform is wider than an inner opening.