JPH0419732Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a sealed lead-acid battery, particularly to an improvement of the exhaust port.

BACKGROUND ART Conventionally, as an exhaust port of a sealed lead-acid battery, a cylindrical exhaust port has a tip end perpendicular to the cylindrical portion.

Problems that the invention aims to solve The function of the valve body of a sealed lead-acid battery is to prevent the battery from bursting due to an abnormal rise in internal pressure when gas is generated during charging, and to prevent the battery from bursting due to a decrease in electrolyte. This prevents short life.

In general, in an exhaust port section that has a structure in which a cylindrical exhaust port 1 is covered with a flexible valve body 2 as shown in FIG. It is determined by the thickness and the contact length L between the cylindrical exhaust port 1 and the valve body 2. That is, the harder the material of the valve body 2 is, the thicker the wall of the valve body 2, or the longer the contact length L between the cylindrical exhaust port 1 and the valve body 2, the higher the valve opening pressure becomes. Changes in battery internal pressure due to valve element operation can generally be represented by a valve operating pressure curve as shown in FIG. The valve opening pressure O is determined within a range that safely maintains the strength of the battery case. In addition, setting the equilibrium pressure S (the battery internal pressure that stabilizes after the valve operates and releases some gas and returns to normal) as high as possible will reduce the amount of electrolyte loss and extend the battery life. becomes. From this, a smaller differential pressure between the valve opening pressure O and the equilibrium pressure S is an advantageous characteristic in terms of battery life performance.

However, in the conventional exhaust port, because the operating pressure of the valve body 2 is uniform at any position on the valve body 2 due to its shape, the valve operation requires a relatively large amount of exhaust to be exhausted at one time until the valve body elastically returns. By allowing
The difference between the valve opening pressure O and the equilibrium pressure S is large. Since the valve opening pressure O is determined by the strength of the battery cell, it has the disadvantage that the equilibrium pressure S is low and the amount of electrolyte decrease is large. This causes short battery life.

Means for Solving the Problems The present invention eliminates the above-mentioned drawbacks, and is a sealed lead-acid battery having a gas exhaust section. , 3'' are covered with a cap-shaped valve body 2, and the opening ends of the cylindrical exhaust ports 3, 3', 3'' It is characterized by being inclined with respect to the length direction.

Function The valve body 2 according to the present invention can make the difference between the valve opening pressure O and the equilibrium pressure C smaller than that of the conventional valve body 2. That is,
When the internal pressure of the battery increases, the valve body 2 and the exhaust ports 3, 3',
The valve is selectively opened at the point where the contact length L of 3″ is the shortest,
The temporary displacement amount until the valve body 2 returns elastically can be limited. Therefore, the difference between the valve opening pressure O and the equilibrium pressure S becomes smaller than in the conventional structure. Furthermore, since the contact length L between the valve body 2 and the exhaust ports 3, 3', 3'' changes continuously, the degree of opening of the valve changes depending on the degree of gas generation. If this occurs, the degree of opening of the valve body 2 is large, and the exhaust port 3,
Since the contact length between 3' and 3'' and the valve body 2 is opened to a point longer than L, the equilibrium pressure S can be maintained higher than in the conventional structure, and it can be exhausted quickly, thereby preventing rupture due to a rise in battery internal pressure. Therefore, even if the valve opening pressure is the same, the equilibrium pressure s is higher than that of the conventional structure, so the amount of loss of electrolyte can be reduced within the range that maintains the strength of the battery safely, and the battery life can be reduced. Performance can be improved.

Embodiment The present invention has the structures shown in A, B, and C in FIG. has been
The contact length with the cap-shaped valve body 2 is partially shortened. The valve operating pressure characteristic curve of the present invention and the conventional valve operating pressure characteristic curve are compared in FIG.
Even though the opening pressure O of the exhaust port section A according to the present invention and the conventional exhaust port section B is the same, the equilibrium pressure S of the exhaust port section A according to the present invention can be maintained at a high level.

As a result, in the battery according to the present invention, the amount of electrolyte loss is reduced, and the battery life performance is improved.

Next, we investigated the life performance of a sealed lead-acid battery C equipped with an exhaust port according to the present invention and a sealed lead-acid battery D equipped with a conventional exhaust port (both are equivalent to the NS40ZA type).
Figure 2 shows the results of a comparison of life tests based on SAE standards at 40°C. As is clear from Figure 2, a sealed lead-acid battery D with a conventional exhaust port
The battery reaches its lifespan after about 5,000 charging/discharging cycles, whereas the sealed lead-acid battery O equipped with an exhaust port according to the present invention has an excellent lifespan of about 6,000 cycles.

Note that in the present invention, the exhaust port is not limited to the shape shown in the embodiment.

Effects of the invention As described above, the invention has great practical value, such as ensuring the safety of sealed lead-acid batteries, reducing the amount of electrolyte loss, and providing excellent battery life.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the exhaust port according to the present invention, A and B are cross-sectional views of the exhaust port in which a part of the end of the exhaust port is formed in an inclined shape, and C is a cross-sectional view of the exhaust port with the entire end of the exhaust port formed in an inclined shape. Fig. 2 is a cross-sectional view of the exhaust port formed in an inclined shape, and Fig. 2 is a performance comparison curve diagram of a sealed lead-acid battery equipped with an exhaust port according to the present invention and a conventional sealed lead-acid battery equipped with an exhaust port. Figure 3 is a sectional view of the conventional exhaust port, and Figure 4 is a cross-sectional view of the conventional exhaust port.
The figure is a comparative characteristic curve diagram of the valve operating pressure between the exhaust port according to the present invention and the conventional exhaust port. 2 is the valve body, 3, 3', 3'' are the exhaust ports.

Claims (1)

[Scope of Claim for Utility Model Registration] A sealed lead-acid battery having a gas exhaust section, which has a cap-shaped valve body 2 covering a cylindrical exhaust port 3, 3', 3''. The opening ends of the cylindrical exhaust ports 3, 3', 3'' are inclined with respect to the length direction of the cylindrical exhaust ports 3, 3', 3''. A sealed lead-acid battery characterized by: