JPS5864763A - Grid for lead acid battery - Google Patents

Abstract

PURPOSE:To control the voltage drop caused by the current applied to a grid and improve the voltage characteristics by providing a collector lug section in the specified area of the transverse frame on top of the grid and specifying the longitudinal and lateral dimensions of the grid and the ratio of the grid weight to the gross weight of its inner frames. CONSTITUTION:A collector lug section is provided in the half area except the central direction from the end of the transverse frame on top of a grid and its center and end. Besides, the longitudinal and lateral dimensions of the grid are set to (a) and (b) and the gross weight of the longitudinal and lateral inner frames is set to (A) and (B), respectively. The grid weight ratio H obtained by (A/a)/(B/b) is set within 0.8<=H<=1 since the effect of sudden discharge voltage increase is saturated when H>=1. As a result, the voltage characteristics of a lead acid battery can be improved sharply.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to improve the voltage characteristics of lead-acid batteries during rapid discharge.

When starting a car using a lead-acid battery installed in a car, a large current of about 100A to 300A usually flows.

At this time, the terminal voltage decreases due to the internal resistance of the battery.

The starting ability of a lead-acid battery can be expressed as the product of the flowing current I and the terminal voltage V (W=IxV). Therefore, a device with low internal resistance during large current discharge is desired.

Factors of internal resistance include resistance polarization of grids, separators, electrolyte, etc. 9 reaction polarization, concentration polarization, etc.

The present invention improves the voltage characteristics by suppressing the voltage drop due to the current flowing through the grid by devising the grid shape and the weight distribution of the backbone.

Conventionally, automotive lead-acid battery grid bodies have been constructed as shown in Figure 1.
A current collecting ear portion 2 is provided at the end of the horizontal frame rib 1 at the upper part of the lattice, and the lateral and vertical bones inside the lattice are shaped to be perpendicular to each other. The value H of a/b, which is the ratio of the total weight A of the vertical backbone per the vertical dimension length a of this lattice and the total weight B of the horizontal backbone B per the horizontal dimension length b, is ○, 3
It falls within the range of ≦H≦05. This ratio is determined from the grid manufacturing process and subsequent manufacturing processes such as paste filling. The lattice body shown in FIG. 1 is normally handled in the form of two plates as shown in FIG. 2 during the casting, filling and drying processes of paste active material.

In the casting process, molten lead alloy is poured from the direction of arrow 3 in the figure, so unless the weight of the horizontal backbone, which is the flow direction of the molten lead alloy, is made heavier, it will be difficult for the molten lead alloy to flow into the vertical backbone, which is perpendicular to this. . Therefore, H≦0.6.

Recently, attempts have been made to reduce the internal resistance caused by the grid. The grid body shown in Fig. 3 allows current to flow through the shortest conductive path toward the current collecting ears 2, and concentrates the amount of lead in the longitudinal ribs near the current collecting ears where the current flowing through the grid is concentrated. , and the bones become thicker as they get closer to the current collecting ear. In this lattice also a /b
The ratio of HΦ0.6. Therefore, from the viewpoint of voltage characteristics, it cannot be said that the lattice body exhibits sufficient performance.

In the present invention, when the current collecting ears 2 are moved toward the center from the ends of the horizontal frame ribs 1 in the upper part of the grid, the total weight or the total number of vertical ribs extending from each part of the grid toward the ears 2 is increased. This is based on the finding that the resistance within the lattice can be significantly reduced and the voltage characteristics can be improved. In other words, in the case of a conventional grid in which the vertical and horizontal ribs are perpendicular to each other, if the weight is the same, the voltage characteristics can be improved by increasing the number of vertical ribs and decreasing the number of horizontal ribs. ”.

For example, Figure 4 a-
Shown in f. All of these grids are 110 mm long x 10 mm wide.
8, and the weight was 35 g. In the figure, a shows a conventional product in which the current collecting ears 2 are provided at the ends of the horizontal frame ribs 1. The ratio -a/b value Hf a -c Vio, was set to 4, and df was set to 1°6.

Using these gratings, 4 anode plates and 6 cathode plates per cell.
A N540 type lead-acid battery (capacity 35 mh at 20 hour rate) was manufactured by combining the sheets, and the voltage at the 5th point end during rapid discharge at -15°C at 1150A was measured.

The results are shown in FIGS. Figure 6 shows the ratio a /b ``'' of the total weight of the vertical spine A per length a in the vertical dimension and the total weight B of the horizontal spine per length b in the lateral dimension without changing the grid weight. 2 is a graph of the voltage improvement value measured from the relationship with the position of the current collecting ear portion 2.

FIG. 6 is a graph showing the voltage improvement value when the position 1'/l of the current collecting ear portion 2 is changed in relation to the value of the weight ratio H. The current collecting ear portion 2 was an end portion of the upper horizontal frame 1, and was a lattice body with the weight ratio H-0.4, with the sudden discharge voltage of the assembled battery as the reference origin.

From the above-mentioned Fig. 6 and Fig. 6, as the weight of the vertical ribs of the lattice increases compared to the weight of the horizontal ribs, the voltage characteristics improve with respect to the current collecting ears, and the effect is synergistic. I understand. Further, when the value H of a /b becomes H≧1, the effect of improving the rapid discharge voltage becomes saturated. Therefore, as an actual usage condition, considering the lattice strength, O08
It is effective to use within the range of ≦H≦1.

B Also, regarding the position of the current collecting ear, the value H of a/b is Hg0
68, from Fig. 6, excluding the center and end on the horizontal frame bone directly below the current collecting ear, if it falls within 1/2 area on the line connecting these two, the sudden discharge voltage direction is almost the same.''2 effect. is in a saturated state, so the object of the present invention can be achieved as long as the position of the current collecting ear is within the 1/2 area.

It has also been found that the present invention can be applied to a lattice body including oblique pipes having a shape as shown in FIG.

Furthermore, it has been found that the voltage characteristics are improved even for gratings with vertical and horizontal dimensions other than those described in the above examples, as long as the above conditions are met.

As described above, the present invention has been made by studying the lattice shape, which has been almost ignored due to the two drawbacks of conventional production, and has discovered that the voltage characteristics of the battery can be significantly improved. Furthermore, production difficulties can be easily resolved by improving production equipment.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional lattice body for lead-acid batteries, FIG. 2 is a diagram showing a two-sheet state in which the lattice body is normally handled, and FIG. 3 is a diagram showing another conventional lattice body. Figures 4 a to f are diagrams showing voltage drop distributions when large currents are passed through various grid shapes in the conventional and present inventions. Total bone weight ratio H
FIG. 6 is a diagram showing the voltage improvement value when changing the current collecting ear portion formation position. 1...Horizontal frame bone, 2...Current collecting ear part. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure m3 Figure 4

Claims (1)

[Claims] The current collecting ears are 1/2 of the horizontal frame at the top of the lattice excluding the center and ends.
If the vertical dimension of the lattice is a1, the length of the vertical mid-bones is 1, and the horizontal dimension of the lattice is B1, the total weight of the horizontal mid-bones is B, then a/b is calculated. A lattice body for a lead-acid battery, characterized in that the lattice weight ratio H is 0.8≦H≦1.