JPS6050035B2 - Method for manufacturing grids for lead-acid batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a grid used in lead-acid batteries, and involves immersing a grid structure made of synthetic resin in molten lead alloy and quickly pulling it up to remove lead from surrounding the synthetic resin. The purpose of this study was to improve performance reliability and productivity by improving the shape of the synthetic resin lattice structure to make it easier for the thin lead film to adhere to it. There are things.

There is an extremely strong demand for reducing the weight of lead-acid batteries these days because it improves fuel efficiency for automobiles, increases mileage for electric vehicles, and makes it easier to carry for portable devices.

However, lead-acid battery grids are typically manufactured by casting lead alloys.

This lead has a heavy specific gravity of 11.3, and it is difficult to cast it to a thickness of 1 Tfrm or less, and there is a certain limit to reducing the weight of a cast grid. The main role of the lattice body is to serve as a conductor during charging and discharging, 2 to hold the active material, and to ensure mechanical strength as a 3-electrode plate.Lead is used only in the 1 part, and the 20 and 3 roles are A so-called lead alloy-synthetic resin composite lattice has been considered, which uses other materials with low specific gravity, such as synthetic resin with a specific gravity about 1/10 that of lead. For example, parts that require conductors are cast in advance with lead alloy,
A method has been proposed in which this is then inserted into a synthetic resin mold and the synthetic resin is poured into it to integrate it and create a lattice.

Also known is a method of making a grid by laminating and bonding a synthetic resin grid and a lead alloy perforated plate.

However, all of these have the drawbacks of poor productivity and high cost due to complicated manufacturing processes and handling.

In the present invention, a lattice structure made of synthetic resin is immersed in molten lead or a lead alloy and quickly pulled up, or molten lead is poured onto the J or synthetic resin body to form a thin film of lead on the synthetic resin body. .

With this method, the manufacturing process is simplified and the grid can be manufactured continuously, so the productivity of the grid is significantly improved. Furthermore, the periphery of the grid is covered with lead alloy,
Since the adhesion to the active material is good and the active material is less likely to fall off, battery assembly becomes easier and the performance of the battery can be improved.

However, the frame frame 1a shown in FIG. 1 has a square cross-section, and the internal active material support frame 1b has a triangular cross-section.A grid structure 1 made of synthetic resin having the same shape as a conventional cast grid is immersed in molten lead. The lattice body manufactured by quickly pulling up had the disadvantage that the thin lead film a easily peeled off at the corners b and could not be coated to a uniform thickness.

The lead-synthetic resin composite lattice body for lead-acid batteries of the present invention is produced by immersing a lattice structure made of a synthetic resin having a rounded cross-sectional shape such as an ellipse or circle in molten lead or a lead alloy, or by immersing it in molten lead or lead alloy. A uniform thin film is formed on the surface by pouring something like this from above.

The contents of the present invention will be explained in detail below with reference to Examples.

The lattice structure 1 made of synthetic resin shown in FIG. 2 is made of polypropylene, polyethylene, polyvinyl chloride, ABS, and AS.
, made of thermoplastic or thermosetting resin material such as phenolic resin, and its cross-sectional shape is circular or oval. Although it is generally desirable to have a circular shape, it is effective to use an elliptical shape when the electrode plate is thick or high mechanical strength is desired. A synthetic resin lattice structure with such a cross-sectional shape is immersed in a molten lead alloy whose temperature is controlled at about 335°C for about 3 seconds, and then quickly pulled up to form a lead thin film 2 with a thickness of about 200p. can be uniformly adhered to the surface of the grating structure 1.

As a result of processing conventional lattices with quadrangular and triangular cross-sectional shapes and the circular cross-sectional shape of the present invention under the above conditions,
In the conventional product with corners, lead does not adhere to the periphery of the lattice with a uniform thickness, as shown in Figure 1 D, but it adheres thickly at part a of B and thinner at part b! Ru. Furthermore, as shown in Figure 3, when the lattice structure has a square cross section of 2T1rm on a side and the molten lead temperature and immersion time are varied, lead adheres to the entire surface of the lattice structure under lead adhesion range condition A; Under condition B, the first
It becomes impossible to form a lead film on part b as shown in Figure D. The principle behind forming a thin lead film on a lattice structure made of synthetic resin is that the melting point of the synthetic resin is lower than the melting point of lead.
When synthetic resin is immersed in molten lead, the synthetic resin absorbs heat and the surrounding molten lead instantly solidifies.

A thin film of lead is then formed by quickly pulling it up. Therefore, if it is immersed for a long time, not only will the synthetic resin melt, but once the lead has solidified, the temperature will rise above its melting point due to the surrounding molten lead and it will melt again, making it impossible to attach a thin lead film. If there is a corner in the cross-sectional shape of the lattice structure, the amount of heat lost by the lead around the synthetic resin lattice structure is smaller when corner b is attached to molten lead than side a.
The thickness of the deposited lead thin film becomes thinner and is easily remelted by the surrounding molten lead, resulting in the result as shown in FIG. 1D.

Therefore, due to control of structural conditions, peeling of the lead gate thin film during the manufacturing process, and breakage of the lead thin film, conductivity is lost and the thickness is not uniform.

In the present invention, since the cross-sectional shape of the lattice structure is circular or elliptical as shown in FIG. As shown in Figure A, the range of lead adhesion conditions has been expanded, making it possible to control manufacturing conditions more freely, eliminating the need for a thin lead film to form during the process, and improving reliability and productivity.

In addition, since the lead shrinks by cooling before the synthetic resin lattice structure cools and shrinks, the adhesion between the synthetic resin body and the lead thin film improves, increasing the strength of the lattice structure and increasing the lead resistance. Corrosion progresses evenly, resulting in improved service life.

As described above, the present invention has a simple structure and high value. Brief description of the drawings Figure 1 shows a conventional lattice structure made of synthetic resin; A is its front view, B is a cross-sectional view along the ero line of A, C is a cross-sectional view after immersing it in molten lead, and D 2 is a cross-sectional view of a lattice structure made of synthetic resin according to an embodiment of the present invention, A is a front view, B is a cross-sectional view along Eiro of A, C is a sectional view after being immersed in molten lead, and FIGS. 3 and 4 are diagrams showing the relationship between molten lead temperature and immersion time to form a lead thin film.

1... Lattice structure made of synthetic resin, 1a...
Frame bone, 1b...Active material supporting bone, 2...Lead or lead alloy thin film.

Claims (1)

[Claims] 1. A lattice structure made of synthetic resin with a rounded cross-sectional shape such as an oval or circular shape is immersed in molten lead or a lead alloy, or the molten material is poured from above to form lead onto the surface of the lattice structure. Or a method for producing a grid for a lead-acid battery, characterized by forming a thin film of lead alloy.