JPH0511315U - Sealed lead acid battery - Google Patents

Abstract

(57) [Summary] [Object] To provide a sealed lead-acid battery that can prevent the valve body of the safety valve from sticking to the exhaust stack and obstructing the release of oxygen gas when the temperature becomes high. [Structure] Safety valve 3 provided on the upper lid 2 of the battery case 1
Is an exhaust pipe 4 that is integrally provided on the upper lid 2, a cap-shaped valve body 5 made of an elastic material that is closely fitted to the tip of the exhaust pipe 4, and the exhaust pipe 4 and the valve body 5. And a shape memory member 6 having an inverted L-shape, the base end of which is fixed to the exhaust pipe 4 in a recessed part of the outer circumference of the exhaust pipe 4 so as to be interposed between the exhaust pipe 4 and the exhaust pipe 4. The shape memory member 6 has a valve body 5 at a high temperature.
A memory is preliminarily given to deform in a direction away from the surface of the exhaust stack 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sealed lead storage battery having a safety valve that releases pressure when the internal pressure of a battery case rises.

[0002]

[Prior Art]

 The cathode absorption type sealed lead-acid battery is hermetically sealed by absorbing oxygen gas generated from the positive electrode plate during charging. The safety valve is fitted in close contact with the exhaust pipe, which is integrally installed in the battery case, and the tip of the exhaust pipe. When the internal pressure in the battery chamber rises, the safety valve is deformed and gas is discharged from between the exhaust pipe. And a valve body made of an elastic material that discharges.

The operating temperature of such a sealed lead-acid battery is mainly 0 to 40 ° C., but depending on the case, it may be exposed to a temperature atmosphere higher than this in the summer. Normally, this type of battery is charged by constant voltage control, and as the temperature rises, the overcharge voltage of the battery drops, so a larger current flows as the temperature rises.

Therefore, while the amount of oxygen gas generated from the positive electrode increases, the gas absorption capacity of the negative electrode increases due to the high temperature, so that heat generation due to oxygen gas absorption increases and the battery temperature rises. Then, a larger current flows, causing an exothermic reaction and increasing the oxygen gas generation amount, and the thermal reaction is repeated. Therefore, the oxygen gas inside the battery is released to the outside by a safety valve.

[0005]

[Problems to be solved by the device]

 However, there is a danger that the valve body of the safety valve will deteriorate due to the high temperature of the battery, and the valve body will adhere to the exhaust stack, and oxygen gas will not be released. Therefore, the internal pressure of the battery rises and the temperature of the battery rises accordingly, which causes deformation and cracking of the battery case, which causes a problem in that the device containing the battery is damaged.

An object of the present invention is to provide a sealed lead-acid battery that can prevent the valve body of the safety valve from sticking to the exhaust stack and obstructing the release of oxygen gas when the temperature becomes high.

[0007]

[Means for Solving the Problems]

 To explain the structure of the present invention to achieve the above-mentioned object, the present invention provides a safety valve in a battery case for accommodating an electrode plate group, the safety valve being an exhaust tube integrally provided in the battery case and the exhaust valve. A valve body made of an elastic material that is fitted in close contact with the tip of the cylinder and is deformed when the internal pressure in the battery case rises to release gas from the exhaust cylinder. The sealed lead-acid battery according to the invention is characterized in that a shape memory member that deforms in a direction of separating the valve body from the surface of the exhaust cylinder at high temperature is interposed between the exhaust cylinder and the valve body. .

[0008]

[Action]

 In this way, when a shape memory member that deforms in the direction of separating the valve body from the surface of the exhaust pipe at high temperature is interposed between the exhaust pipe and the valve body, when the temperature becomes high, the shape memory member Deforms into a shape stored in advance, that is, a shape in which the valve element is separated from the surface of the exhaust pipe. For this reason, a gap is formed between the exhaust stack and the valve body, and it is possible to avoid the situation where it becomes difficult to release oxygen gas from the safety valve at a high temperature.

[0009]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2. As shown, a safety valve 3 is provided on the upper lid 2 of the battery case 1. The safety valve 3 includes an exhaust pipe 4 integrally provided on the upper lid 2, and a cap-shaped valve body 5 made of an elastic material such as chloroprene rubber, which is fitted in close contact with the tip of the exhaust pipe 4. An inverted L-shaped shape memory member having a base end fixed to the exhaust pipe 4 in a recessed part of the outer periphery of the exhaust pipe 4 so as to be interposed between the exhaust pipe 4 and the valve body 5. 6 and 6. The orthogonal bending portion 6a of the shape memory member 6 is placed on the bud portion at the tip of the exhaust pipe 4. The shape memory member 6 is provided with a memory for deforming the valve body 5 at a high temperature in a direction away from the surface of the exhaust pipe 4 as shown in FIG. In this example, a TiN alloy having a transformation temperature of 80 ° C. was used as the shape memory member 6. Further, ABS resin was used as a constituent material of the battery case 1.

In such a sealed lead-acid battery, when the temperature becomes high, the shape memory member 6 has a shape stored in advance as shown in FIG. 2, that is, a shape in which the valve body 5 is separated from the surface of the exhaust pipe 4. Transforms into. For this reason, a gap is formed between the exhaust pipe 4 and the valve body 5, and it is possible to avoid a situation in which it becomes difficult to release oxygen gas from the safety valve 3 at a high temperature.

The batteries of the conventional product and the device of the present invention were allowed to stand at 50 ° C. for 3 months and then subjected to an overcharge test at a constant current of 0.1 CA. As a result, in the conventional product, the valve body 5 did not come into close contact with the exhaust stack 4 and the valve body 5 did not operate, so 0.3% of the batteries were deformed by the battery case due to the temperature rise of the battery. However, the battery according to the present invention did not cause any deformation of the battery case.

The material of the safety valve 3 of the sealed lead-acid battery according to the present invention is not limited to those mentioned above. For example, the shape memory member 6 may be made of shape memory plastic. Further, the shape of the shape memory member 6 is not limited to the shape described above.

[0013]

[Effect of the device]

 As described above, in the sealed lead-acid battery according to the present invention, the shape memory member that deforms in the direction of separating the valve body from the surface of the exhaust cylinder at high temperature is interposed between the exhaust cylinder and the valve body. Therefore, when the temperature becomes high, the shape memory member can be deformed into a shape that is stored in advance, and the valve body can be deformed in a direction away from the surface of the exhaust pipe. For this reason, a gap is formed between the exhaust stack and the valve body, and it is possible to avoid the situation where it is difficult for oxygen gas to be released from the safety valve at high temperatures, and it is possible to prevent deformation of the battery case.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a safety valve portion of an embodiment of a sealed lead-acid battery according to the present invention.

FIG. 2 is a vertical sectional view showing an operating state of the safety valve shown in FIG. 1 at a high temperature.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Battery case, 2 ... Top lid, 3 ... Safety valve, 4 ... Exhaust pipe, 5 ... Valve body, 6 ... Shape memory member, 6a ... Bending part.

Claims (1)

[Claims for utility model registration] 1. A safety valve is provided in a battery case accommodating the electrode plate group, and the safety valve is an exhaust cylinder integrally provided in the battery case, and a tip portion of the exhaust cylinder. A lead-acid battery sealed with the valve body made of an elastic material that is fitted in close contact with and is deformed when the internal pressure in the battery case rises to release gas from the exhaust pipe The sealed lead acid battery according to claim 1, wherein a shape memory member that deforms at a high temperature in a direction separating from the surface of the exhaust pipe is interposed between the exhaust pipe and the valve body.