JPH04111145U - sealed lead acid battery - Google Patents

Abstract

(57) [Summary] [Purpose] Prevent damage to the surrounding area even if an explosion occurs inside. [Structure] In a sealed lead-acid battery in which the exhaust pipe 1 is equipped with a safety valve 5 that opens at a predetermined battery internal pressure, the opening area of the exhaust pipe 1 is the maximum area of the cross section of the space 6 above the electrode group in the battery. Make it 1% or more. Even if an explosion occurs inside, the energy will be effectively released to the outside by the safety valve, so the storage battery will not explode.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a cathode absorption type sealed lead acid battery equipped with a safety valve.

0002

[Conventional technology]

Generally, a sealed lead-acid battery has a space between the top of the electrode plate group and the back surface of the lid. Normally, the oxygen gas inside a sealed lead-acid battery is absorbed by the negative electrode plate, so the Almost no oxygen gas exists in the inner space. Also, due to overcharging, oxygen gas is removed from the positive electrode plate. However, even if hydrogen gas is generated from the negative electrode plate, the negative electrode plate absorbs oxygen gas. During this time, almost no oxygen gas is present in the internal space. However, oxygen gas If the battery has been overcharged such that the raw velocity exceeds the oxygen gas absorption capacity of the negative electrode plate. In this case, hydrogen gas and oxygen gas will be present in the internal space. hydrogen gas If the gas concentration is 4% or more, there is a risk of explosion due to the generation of some kind of ignition point. have. In the unlikely event that a sealed lead-acid battery explodes, fragments of the battery There is a risk that the liquid will scatter into the surrounding area and cause damage to peripheral equipment.

0003 For this reason, as in JP-A No. 56-136453 and Utility Model Application No. 63-135760, It has been proposed to reduce the thickness of a portion of the lid. These are sealed lead acid batteries. Although effective against ruptures caused by a slow rise in internal pressure, explosions It was not very effective against instantaneous rupture due to This only applies to the structure in question. This was due to the inability to absorb the energy of the explosion.

0004 This invention was created to solve this problem, and its purpose is to Even if an explosion accident like the one mentioned above occurs, it will not cause damage to peripheral equipment. What measures should we take to provide a non-hazardous sealed lead-acid battery? That's the point.

[0005]

[Means to solve the problem] In order to solve these problems, this invention has a safety valve attached to the exhaust stack. In a sealed lead-acid battery, the opening area of the exhaust stack is defined as the cross section of the space above the electrode group inside the battery. Adopts a sealed lead-acid battery storage battery characterized by 1% or more of the maximum surface area. did.

[0006]

[Effect]

Sealed lead-acid batteries generally require an exhaust pipe that communicates with the internal space above the electrode group. A pressure valve with operating characteristics is installed, and the aperture area of the exhaust pipe is set as a cross section of the internal space. By making the area more than 1% of the maximum area of the can be effectively released to the outside of the storage battery. Therefore, the storage battery may explode. There is no fault.

[0007]

【Example】

The present invention will be described below based on drawings showing embodiments thereof. Figure 1 shows the present invention. FIG. 2 is a schematic cross-sectional view of one embodiment of a sealed lead-acid battery, and FIG. 2 is a schematic cross-sectional view of main parts of another embodiment. Ru. In FIG. 1, 4 is an exhaust pipe, and in this embodiment, a concave portion is formed in the lid 4. It is buried within the recess. The space 6 above the electrode group inside the storage battery is connected to the outside by the exhaust pipe 4. It communicates with space. The exhaust pipe 4 has a cap-shaped cap made of a rubber elastic material. A safety valve 5 is installed, and the safety valve 5 is further attached to the lid 4 by fitting or welding. It is supported by a top lid 2. The safety valve 5 is generally specified in the specifications of sealed lead-acid batteries. It has the same operating characteristics as the existing one.

[0008] Hydrogen gas and oxygen gas generated due to excessive overcharging pass through the exhaust stack 4 and return to the exhaust stack 4. and the safety valve 5, and further passes through the exhaust hole 3 provided in the top cover 2 to the outside of the storage battery. leaks to the department. Conversely, when the internal space of the storage battery becomes depressurized, atmospheric pressure The exhaust pipe 4 and the safety valve 5 are brought into close contact with each other, and the gap is closed. The safety valve is created in this way. use

[0009] Using a sealed lead-acid battery with the above configuration, the maximum cross-sectional area of the internal space 6 above the electrode plate group is Explosion tests were conducted by changing the ratio of the size of the opening area of the exhaust stack 4 to the product. test After the battery is fully charged, it is overcharged for about 30 minutes at a 5-hour rate current. by igniting an ignition source (not shown) such as a fuse or electrode installed in the It was. In addition, in this invention, the cross section of the internal space at the top of the electrode plate group refers to the cross section of the internal space at the top of the electrode plate group This is the case when the upper part of the board group is cut in the horizontal direction (B-B' direction in Figure 1). It means the space that fits into the cut surface.

0010 Table 1 shows the test results. As is clear from the table, this test shows that the electrode plate The size of the opening area of the exhaust pipe 4 with respect to the maximum area of the cross section of the internal space 6 in the upper part of the group is It has been found that by increasing the concentration to 1% or more, it is possible to prevent explosions and scattering of storage batteries. It was. With this configuration, the energy of the explosion is stored from the safety valve 5. This means that a means for effectively escaping to the outside of the battery has been achieved. In this test, the above ratio was varied up to 5%, but even higher ratios are effective. That is clear. In implementation, we will take into account the usage and configuration of sealed lead-acid batteries. It can be set more appropriately.

[0011] Note that this invention applies only to sealed lead-acid batteries that use the cap-shaped safety valve shown in Figure 1. A safety valve of any shape may be used, for example, as shown in Figure 2. Even in a plate-shaped safety valve structure, if the opening area of the exhaust pipe is set to 1% or more, It has the same effect.

0012

[Effect of the idea]

According to this invention, even if an explosion occurs due to gas generated inside a sealed lead-acid battery, the Damage to the edges can be greatly reduced using inexpensive materials and a simple structure; It has great practical value.

[Table 1]

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of one embodiment of a sealed lead-acid battery according to the present invention.

FIG. 2 is a schematic sectional view of main parts of another embodiment of the sealed lead-acid battery according to the present invention.

[Explanation of symbols]

1 Exhaust stack 2 Top lid 3 Exhaust hole 4 Lid 5 Safety valve 6 Space above the electrode group

Claims (1)

[Scope of utility model registration request] Claim 1: In a sealed lead-acid battery with a safety valve (5) attached to the exhaust pipe (1), the opening area of the exhaust pipe (1) is defined as the cross section of the space (6) above the electrode group in the storage battery. A sealed lead-acid battery characterized in that the area is 1% or more of the maximum area of the battery.