JP2002110123A - Control valve type lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safe and highly reliable control valve type lead-acid battery having a structure of an exhaust valve which eliminates suction of outside air into a battery, enables prompt discharge of gas and easy production. SOLUTION: A exhaust valve is provided to the upper part of a battery container. By a buildup of battery internal pressure, the control valve type lead-acid battery discharges the gas inside the battery container to the outside through the exhaust valve. Exhaust holes provided corresponding to respective cells are mounted in a recess of the upper part of the battery container. A rubber plate covering the exhaust hole is provided with a swollen part fit into the recess.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust part structure of a control valve type lead-acid battery.

[0002]

2. Description of the Related Art In a control valve type lead-acid battery, gas generation exceeding the gas absorption reaction at the negative electrode at the time of charging with a large current, the accompanying increase in internal pressure, prevention of battery damage, and prevention of atmospheric pressure when the battery internal pressure decreases. An exhaust valve is used to prevent inflow into the battery, and this is the name.

In recent years, control valve type lead-acid batteries are often used in various environments because of their convenience, and they are often installed in electric equipment or outdoors so that they can be used at particularly high temperatures. Use in the environment is increasing. At the time of use at such a high temperature, the elasticity of the battery case resin becomes smaller.
Even under such pressure, the battery is deformed, and the pressure of the electrode plate group is reduced to cause a reduction in capacity, or a problem such as breaking of the battery in the limit occurs. Further, since the internal space of the battery is composed of oxygen gas and hydrogen gas due to the characteristics of a lead battery, and has an explosive gas, it is desirable that the battery be quickly discharged from the battery even at a small pressure.

In addition, when the inside of the battery is depressurized, if external air is sucked in, the metal lead on the negative electrode plate is oxidized and the battery is deteriorated.

[0005] In other words, the characteristics required for the exhaust valve of a lead storage battery are firstly that air is not sucked into the battery, and second that the valve is opened at a pressure as low as possible and gas in the battery is released. is there.

[0006] In response to such required characteristics, at present, the following two types of exhaust valves, a cap valve and a plate valve, are generally used.

FIG. 3 shows an exhaust valve generally called a cap valve, and is a cross-sectional view showing the exhaust portion structure. The structure includes a cap valve 9 that covers the exhaust hole 3 of the lid and an upper lid 5 that suppresses the cap valve. In this valve structure, in a battery having a plurality of exhaust holes, a separate cap valve is mounted for each exhaust hole,
It was necessary to attach caps to individual exhaust holes. Also, in this method, the operating pressure for opening and closing is determined by the size and hardness of the cap, so in order to open the valve at a low pressure, the method of reducing the thickness and hardness was adopted,
This is not preferred in terms of rubber aging resistance. In addition, increasing the inner diameter of the cap to lower the valve opening pressure contradicts the reliable closing of the valve, and has a problem from the viewpoint of reliability.

Next, an exhaust valve called a generally used plate valve shown in FIG. 4 comprises a rubber plate 10 covering the exhaust hole 3, a sponge-like rubber mat 11, and an upper lid 5. I have. By mounting the sponge-like rubber mat in a compressed state, the rubber plate is pressed against the exhaust hole of the lid, and the gas is released due to the pressure difference between the battery internal pressure and the sponge-like rubber mat. In this structure, the use of a rubber plate and a rubber mat that collectively covers a plurality of exhaust holes has greatly improved workability.

In this method, the pressure of the on-off valve is controlled by the compression force of the rubber mat. Here, when the battery is pressurized due to gas generated inside the battery when charged with a large current, the rubber plate pushes up the rubber mat and tries to flow out of the battery, but the plate is a rubber mat compressed on all sides. Because it is continuously held down by
There is a disadvantage that it is difficult to open the valve. The pressure at which the valve is opened,
In order to lower the valve opening pressure, the compression force of the rubber mat may be reduced, but it is important that the valve be reliably closed when the inside of the battery is depressurized, and it is difficult to control with the compression force.
Further, a sponge-like rubber mat is required.

[0010]

As described above, the control of the on-off valve pressure is controlled by the tightness of the cap with respect to the valve hole, that is, the tensile strength in the cap valve, whereas the compression force of the rubber mat is controlled in the plate valve. Is controlled by In these conventional exhaust valves, it is necessary to increase the tensile strength in the cap valve and increase the compressive force in the plate valve in order to reliably close the valve, which is the first condition for operating the battery. Is the same as making valve opening difficult at the same time, causing a phenomenon that the valve opening pressure increases,
A valve that opens and closes stably at a low pressure of 10 kPa or less was not obtained.

[0011]

According to the first aspect of the present invention,
An exhaust valve is provided at the top of the battery case.
In a control valve type lead-acid battery that discharges gas inside the battery case to the outside from an exhaust valve, an exhaust hole provided for each cell is provided in a recess provided in the upper portion of the battery case, and a rubber covering the exhaust hole is provided. A control valve type lead-acid battery, wherein the plate is a molded product having a bulge portion fitted into the recess.

According to a second aspect of the present invention, in the control valve type lead-acid battery according to the first aspect, a slit is provided in the exhaust portion where the rubber plate is in contact with the recess.

[0013] The invention according to claim 3 is the invention according to claim 1 or 2.
In the control valve type lead-acid battery described in the above, the valve opening pressure of the exhaust valve is 1
It is characterized by being between kPa and 10 kPa.

According to a fourth aspect of the present invention, in the control valve type lead-acid battery according to the first, second or third aspect, a recess is provided at a position corresponding to the recess on the lower surface of the upper lid for holding down the rubber plate. I do.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In a control valve type lead storage battery according to the present invention, a depression is provided at an upper portion of each cell in a control valve type lead storage battery in which gas in a battery case is discharged to the outside from an exhaust valve due to an increase in battery internal pressure. An exhaust hole is provided in the recess, and a molded product provided with a bulge portion just fitted into the recess is used as a rubber plate valve covering the exhaust hole. In addition, a slit is provided in the exhaust portion where the rubber plate contacts, which communicates with the depression. Further, the valve opening pressure of the exhaust valve is adjusted to 1 kPa to 10 kPa,
A recess is also provided at a position corresponding to the recess on the lower surface of the upper lid for holding down the rubber plate.

According to the present invention, when the inside of the battery is depressurized, the rubber molded product is in the shape at the time of molding, and fits and adheres to the recess around the exhaust hole to prevent the inhalation of outside air, and when the battery is pressurized. The molded rubber at the bulge portion is deformed to the opposite side of the exhaust hole and quickly releases gas. Therefore, by using the restoring force of the rubber material, it is possible to reliably operate with a slight pressure difference.

According to the present invention, an exhaust valve structure can be provided in which no outside air is sucked into the battery and the gas in the battery is quickly released, and the safety and reliability of the control valve type lead-acid battery are remarkably improved. Can be improved.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing one embodiment. FIG. 1 is a sectional view of an exhaust valve used in the lead-acid storage battery of the present invention. A substantially spherical recess 2 is provided in an exhaust portion of the lid 1, and an exhaust hole 3 communicating with the inside of the battery is provided at the bottom of the recess 2. Further, a molded plate valve 4 is overlapped so as to cover this exhaust part, and the upper part thereof is fixed by an upper lid 5. Chloroprene rubber is used for the molded plate valve 4,
Silicon oil (not shown) was applied. Further, the molded plate valve 4 is provided with a bulge portion 6 at a position where the bulge portion 2 just fits into the recess 2 of the exhaust portion. In the present embodiment, the recess 7 is also provided in the upper lid 5 in order to ensure the release of gas when the valve is opened. The upper lid 5 was ultrasonically welded to the lid 1 for fixing.

FIG. 2 is an exploded perspective view showing the molded plate valve 4 and the exhaust hole 3. Two slits 8 through which gas passes when the valve is opened are provided for each cell. When the internal pressure of the battery is reduced, the molded plate valve 4 keeps its shape at the time of molding and is in close contact with the lid 1, so that no outside air is sucked. However, when the internal pressure of the battery becomes higher than the atmospheric pressure due to overcharging or the like, a force deforming from the concave to the convex acts on the bulge portion 6 of the molded plate valve 4 to release gas. Also, when the gas release ends and the battery internal pressure becomes substantially equal to the atmospheric pressure, the deformed molded plate valve 4
Returns to the original concave shape, and the close contact with the depression 2 around the exhaust hole is reliably performed.

The following experiment was conducted to measure the specific on-off valve pressure. Products A to D of the Present Invention and Conventional Cap Valve E
And using the plate valve F, the on-off valve pressure was measured. In addition, battery swelling was measured. Table 1 shows the results.

[0021]

[Table 1] In the experiment, the gas was supplied into the battery and the pressure in the battery when the valve was opened was set as the valve opening pressure, the gas supply was stopped when the valve was released, and the pressure when the valve was closed again was set as the valve closing pressure. I have. For battery swelling, use a 12V40Ah type battery, and use the above-mentioned A to F for the exhaust part structure.
The difference (per surface) between the battery dimensions charged at 5 V / cell and the initial dimensions was measured.

In the product of the present invention, the opening of the valve could be confirmed stably at a low pressure, and the valve was surely closed. Also, by opening and closing at a low pressure, the swelling of the battery could be suppressed even at a high temperature as compared with a conventional valve.

In the description of the present embodiment, a substantially spherical hollow is used. However, the purpose is to be able to closely adhere to the shape of the convex molded product of the rubber material, and various shapes such as a conical shape and a parabolic shape are used. Can take shape. Similarly, in this embodiment, the rubber material is chloroprene rubber. However, the gist of the present invention lies in the structure of the exhaust unit, and EPDM rubber, fluoro rubber, and the like can be used, and the material is not specified.

[0024]

The product of the present invention does not cause battery case deformation when used at high temperatures, and is easy to produce.
An exhaust valve structure can be provided in which the outside air is not sucked into the battery and the gas in the battery is quickly released, so that the safety and reliability of the control valve type lead storage battery can be remarkably improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an exhaust valve used in a lead-acid battery of the present invention.

FIG. 2 is an exploded perspective view showing a molded plate valve and an exhaust hole in the lead-acid storage battery of the present invention.

FIG. 3 is a cross-sectional view showing an exhaust portion structure of a conventionally used cap valve.

FIG. 4 is a cross-sectional view showing an exhaust portion structure of a conventionally used plate valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cover 2 Depression 3 Exhaust hole 4 Molded plate valve 5 Upper lid 6 Swelling part 7 Depression of upper lid 8 Slit 9 Cap valve 10 Rubber plate 11 Sponge-like rubber mat

Claims (4)

[Claims] An exhaust valve is provided in an upper portion of a battery case, and a vent valve provided for each cell in a control valve type lead-acid battery in which gas in the battery case is discharged from the exhaust valve to the outside when the internal pressure of the battery rises. Is provided in the hollow provided at the top of the battery case,
A rubber valve covering the exhaust hole is a molded product having a bulge portion fitted into the recess. 2. The control valve type lead-acid battery according to claim 1, wherein a slit communicating with the recess is provided in an exhaust portion in contact with the rubber plate. 3. The valve opening pressure of an exhaust valve is 1 kPa to 10 kPa.
The control valve type lead-acid battery according to claim 1 or 2, wherein: 4. The control valve type lead-acid battery according to claim 1, wherein a recess is provided at a position corresponding to the recess on the lower surface of the upper lid for holding down the rubber plate.