JPH0352183B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for determining the properties of electrode plates for lead-acid batteries.

In general, electrode plates for lead-acid batteries are made by filling a grid made of lead alloy with a paste made by kneading lead oxide and dilute sulfuric acid, immediately partially drying it, and then leaving it in high humidity for a certain period of time. After storage, it is left exposed to the atmosphere until it is assembled into a lead-acid battery. The period of this leaving is determined based on the experience that leaving the battery for a long time shortens the life of the battery, and the cause is thought to be lead carbonation. For this reason, we have a production plan that does not leave the products unused for long periods of time, but many types of unformed electrode plates are often left unused for long periods of time until they are assembled.

For this reason, it is necessary to judge whether or not the left unformed electrode plate can be used, and as a method to solve this problem, a simple and accurate judgment method is provided. In other words, by making a small plate-shaped paste plate and leaving it together with the unformed electrode plate, and measuring the folding strength of the paste plate at appropriate times, the relationship between the amount of lead carbonate in the plate and the folding strength can be used to determine the strength of the plate. This is a method for determining usage. FIG. 1 is a plan view of a sample plate 1, which is made of metal such as aluminum. This has a cross section as shown in FIG. 2, and by filling the opening 2 of the sample plate 1 with paste, a paste plate 4 having a trapezoidal cross section as shown in FIG. 3 is made. In this case, the paste is filled into the opening 2 and the recess 3 to improve filling performance, but due to various processes in the manufacturing process, it is difficult to obtain a neat trapezoidal paste plate, and the folding strength test to be measured later is difficult. It is difficult to obtain a satisfactory sample. Note that this folding test is a test in which both ends of the paste plate 4 are placed on a support stand and the maximum load when pressing the center of the upper part with a needle is measured.

After examining the reason why a perfectly shaped paste plate could not be obtained, it was found that the most significant cause was the adhesion between the paste plate 4 and the sample plate 1 at the opening 2. Even if the wall of opening 2 is finished like a mirror, corrosion due to various treatments during the manufacturing process,
Alternatively, even if the sample plate is cleaned for reuse, the paste may remain in some places, so that the paste plate 4 immediately adheres to the sample plate and is difficult to remove. After considering various materials, it was found that the opening could be covered with heat-resistant and acid-resistant synthetic resin.

An example thereof is shown in FIG. Size 100×105
On one side of the sample plate 1 in Fig. 1 of ×2.5 mm,
If the opening 2 has a top surface of 15 x 20 mm, a bottom surface of 14 x 19 mm, and a thickness of 2.5 mm (the thickness is shown quadrupled for explanation), cover the inner wall of the opening 2 with polypropylene 5. Manufactured by injection molding. If the wall surface of the opening 2 is made of synthetic resin in this way, the paste board filled therein can be easily taken out.
The back surface also remains smooth for a long time, and the sample plate 1 can be used many times by washing.

FIG. 5 shows the folding strength when the paste plate 4 of the present invention was left together with the unformed electrode plate. The shaded area 6 in the figure is the value measured using the paste plate of the present invention, and it can be seen that there is little variation. On the other hand, in the conventional method, there were large variations as shown in the range 7 in the figure, and there was data that was completely broken during sampling in addition to this data.

As described above, the data obtained by the present invention is stable and convenient for determining unformed electrode plates that have been left unused. The criteria for judgment is that the amount of carbonation during storage is 4% (in terms of lead carbonate), and the level is 250g, which is the sum of the 50g increase in folding strength at this time and 200g of folding strength at the start of storage. I have to. Of course, the folding strength differs depending on the type of electrode plate and paste type, so it is best to create a judgment table for each type.

The present invention has great effects, such as being able to stably and reliably determine the properties of unformed electrode plates that have been left unused.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a sample plate in an embodiment of the present invention, and FIG.
3 is a sectional view taken along line A', FIG. 3 is a sectional view showing a paste plate filled into the opening in FIG. FIG. 5 is a diagram showing the measurement result area of the folding strength of the paste board. 1 is a sample plate, 2 is an opening, 3 is a recess, 4 is a paste plate, 5 is polypropylene, 6 is a data area according to the present invention, and 7 is a data area according to a conventional method.

Claims (1)

[Claims] 1. A sample plate in the shape of an electrode plate, which has an opening for molding a paste plate and the periphery of the opening is made of heat-resistant and acid-resistant synthetic resin, is left after going through the process of filling paste with the regular electrode plate, A method for determining the properties of a lead-acid battery electrode plate, characterized in that the paste plate is then extracted from the opening of the sample plate, and the change in properties of the filled electrode plate while it is being left is determined based on the folding strength of the paste plate.