JPH066455Y2 - Exhaust valve for sealed storage battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to an improvement of an exhaust valve in a small sealed storage battery.

2. Description of the Related Art In a negative electrode absorption type sealed lead-acid battery that absorbs oxygen gas generated from a positive electrode plate by reacting with the negative electrode plate, a cylindrical exhaust hole 4'provided in a battery case lid 3 is provided as shown in FIG. Attach a cap-shaped exhaust valve 5'made of soft rubber or the like. When an abnormality occurs in the storage battery and the internal pressure of the battery rises excessively, the safety valve operates and discharges gas to the outside as shown by the arrow in the figure.When the internal pressure of the battery falls below the operating value, the safety valve returns to the original closed state and the outside air Has a structure that does not enter the battery.

However, in the conventional device, there is a limit to miniaturization from the viewpoint of reliability, and the exhaust valve portion bulges outside the battery case, resulting in poor volume efficiency of the battery. In particular, it was difficult to apply it to flat type batteries. As a suitable one for this miniaturization, there is a proposal that an elastic body is simply pressed against an exhaust port to form an exhaust valve. However, this method generally has a very high valve opening pressure of several atmospheres and is not suitable for a sealed lead acid battery using a synthetic resin battery case. There are also exhaust valves that lightly press the plate-like elastic body to reduce the valve opening pressure, but it cannot be said that the airtightness is sufficient, and it may not be possible to prevent outside air from entering the battery. It was Invasion of outside air oxidizes the electrode plate and is fatal to the sealed storage battery, so it must be completely prevented.

Means for Solving the Problems The present invention has been made to solve the above-mentioned drawbacks, and is provided with a taper so that the portion of the exhaust hole facing the outside of the housing becomes divergent, and the exhaust hole with this taper is provided. A plate-like elastic body is brought into contact with the upper part of the plate-like elastic body, and the upper part of the plate-like elastic body is pressed by an upper lid having a conical projection, so that an exhaust valve having a simple structure, a small size, and a reliable structure is provided. It is a thing.

Embodiments FIG. 1 is a longitudinal sectional view showing an embodiment of an exhaust valve for a sealed type storage battery according to the present invention, and FIGS. 2 (a) and 2 (b) are enlarged sectional views of a main part in FIG. In the figure, 1 is an electrode plate group, 2 is a battery case, and 3 is a battery case lid. Reference numeral 4 is an exhaust hole provided in the battery case lid 3, and a portion facing the outside of the battery is provided with a taper of an angle θ so as to be widened toward the end. Reference numeral 5 is a plate-like elastic body made of a material having excellent acid resistance and rich in rubber elasticity, and the exhaust hole 4
Is abutted on the outside of. Reference numeral 6 denotes an upper lid provided with a conical projection 7, which is configured to press the plate-shaped elastic body 5 from the outside. Reference numeral 8 is a gas vent hole. 9 and 10 are positive
It is a negative pole.

Now, the operation of the exhaust valve of the sealed type storage battery configured as described above will be briefly described. When the gas generated in the battery rises above a predetermined pressure, as shown in FIG. The body 5 is deformed and gas is released as shown by the arrow in the figure. When the pressure becomes lower than a predetermined pressure, the plate-like elastic body returns to its original position as shown in FIG. 2 (a) and comes into close contact with the battery case lid to prevent outside air from entering. Oxygen gas generated from the positive electrode plate reacts with the negative electrode plate and is absorbed, so that the pressure inside the battery is reduced and the plate-like elastic body 5 is adsorbed in the exhaust hole 4. In this case, since the exhaust hole 4 is provided with a taper with an angle θ, the plate-like elastic body 5 adheres to this tapered surface due to the pressure difference between the inside and the outside due to the pressure reduction, and the contact area increases as the gas pressure in the battery decreases and the degree of adhesion increases. As it grows larger, the ingress of outside air is completely blocked. If the exhaust hole is not tapered, the plate-like elastic body and the exhaust hole are only in line contact with each other, and the reliability of airtightness is deteriorated.

Next, as an exhaust valve of a sealed lead-acid battery with a nominal capacity of 0.5 Ah, a neoprene rubber having a thickness of 1 mm is attached to a plate-like elastic body with the above exhaust valve structure, a space height H of the upper lid 6 and the battery case lid 3 is 1.2 mm, and the upper lid is The height of the protrusion 7 is 1.0 mm, the diameter of the upper part of the exhaust hole is 3.5 mm, the diameter of the lower part of the exhaust hole is 2.5 mm, and the diameter of the exhaust hole is 3.5 mm without taper. The following table shows the valve opening pressure and valve closing pressure of the exhaust valve. The amount of gas generated in the battery was 5 cc / min.

As is apparent from the above table, the exhaust valve according to the present invention has a small difference between the valve opening pressure and the valve closing pressure by providing the taper so that the airtightness can be sufficiently maintained. The material of the plate-shaped elastic body,
It goes without saying that the valve opening pressure and the valve closing pressure can be adjusted by the pressing force of the plate-like elastic body and the size of the exhaust hole diameter. Further, the exhaust valve of the present invention is constructed so as to prevent the invasion of outside air by utilizing the suction force at the time of depressurization, so that the plate-like elastic body itself is not sucked into the exhaust hole by the suction force at the time of depressurization. In addition, the size of the exhaust hole, the degree of taper, the thickness of the plate-like elastic body should be adjusted so that the plate-like elastic body returns to the original state (the state where it is simply pressed by the upper lid protrusion) when the suction force is lost. The sheath elasticity and the like are appropriately selected.

As described above, according to the present invention, the plate-shaped elastic body is brought into contact with the tapered exhaust hole, and the top end of the plate-shaped elastic body is pressed by the upper lid having the conical projection so that the lead-acid battery is sealed. Since the exhaust valve can be configured, it has an advantage that it has an extremely simple structure and the operating pressure can be easily adjusted, and that the proportion of the exhaust valve in the battery can be reduced, which can greatly contribute to the downsizing of the battery. Have. Further, when the pressure is reduced, the plate-like elastic body is brought into close contact with the tapered portion of the exhaust hole due to the suction force, and the invasion of outside air can be completely prevented.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of an exhaust valve for a sealed storage battery of the present invention, and FIG. 2 is an enlarged sectional view of an essential part of the embodiment of the present invention shown in FIG. The state when the valve is open, and (b) shows the state when the valve is opened. FIG. 3 is a longitudinal sectional view of a main part showing one row of check valves conventionally used in a sealed lead-acid battery. 1 ... Electrode plate group, 2 ... Battery case, 3 ... Battery case cover, 4 ... Exhaust hole, 5 ... Plate-like elastic body, 6 ... Top cover, 7 ... Conical projection

Claims (1)

[Scope of utility model registration request] 1. A taper is provided so that a portion of the exhaust hole facing the outer side is widened toward the end, and a plate-shaped elastic body is brought into contact with the tapered exhaust hole so that a conical shape is formed from an upper portion of the plate-shaped elastic body. An exhaust valve for a sealed type storage battery, characterized in that a plate-shaped elastic body is brought into line contact with an upper edge portion of the taper pressed by an upper lid having a protrusion.