JPS6325461B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the improvement of grids used in the electrode plates of lead-acid batteries, and involves coating a synthetic resin grid with a thin layer of lead on the surface of the grid by immersing a synthetic resin grid in molten lead alloy and quickly pulling it up. In the method of forming the film, it is possible to reduce the amount of lead used by forming the lead film only on the parts that require conductivity, thereby further promoting weight reduction of the lattice body and, by extension, the weight of the lead-acid battery. This is the purpose.

There is a strong desire to reduce the weight of lead-acid batteries for purposes such as improving fuel efficiency in automobiles, extending mileage in electric vehicles, and making them easier to carry in portable devices. Therefore, the lead grid of the electrode plate is cast or made of lead sheet metal, and the specific gravity of lead is 11.4.
Instead of synthetic resin, which is only about 1/10 of by momentary immersion in molten lead, or
(hereinafter referred to as the immersion method) or by applying molten lead to form a lead film on the surface of the synthetic resin.
According to this method, the manufacturing process is relatively simple and continuous production is possible, so productivity can be increased.

FIG. 1a shows a synthetic resin lattice body manufactured by the above-mentioned conventional method. In the figure, the blacked out areas represent the areas where the lead coating was formed by the above-mentioned dipping method. However, if you think about it carefully, there are still parts in the structure shown in Figure 1a where the lead coating can be saved.

FIG. 1b shows an example of a synthetic resin lattice body coated with the minimum necessary amount of lead, with the blacked-out portions being coated with lead. In order to realize something like this using the immersion method, it is necessary to create two surfaces: one on which the lead film will adhere even if the immersion method is applied, and one on which it will not.

The present invention relates to a method of achieving the above two surfaces to minimize lead coating and promote weight reduction.

This method will be described in detail below with reference to three embodiments with reference to the drawings.

(1) Figure 2 is an explanatory diagram of the first embodiment, where A is the diameter 2
mm synthetic resin or polypropylene with a smooth surface, B is the same diameter and made of the same material, and has fine protrusions all over its surface. This A and B
When it was immersed in molten lead at a temperature of 337°C for 0.4 seconds and pulled out, it was found that A had a 30 μm thick lead coating, but B had no coating. This is A
In case B, the heat is absorbed by the molten lead surrounding the synthetic resin, and the lead approaches the surface of the synthetic resin and is pulled up at the moment it solidifies and adheres to it. In case B, the fine protrusions melt first and solidify. It is thought that this prevented the adhesion of lead.

(2) Figure 3 is an explanatory diagram of the second embodiment, where A is polypropylene with a thickness of 2 mm, width of 5 mm, and length of 30 mm with many holes and grooves drilled on its surface, and B is the same material. It has a smooth surface with no holes or grooves. When A and B were immersed in molten lead at a temperature of 345° C. for 0.4 seconds and pulled out, A had a lead coating, while B had no coating. This is because in case A, the lead that solidifies quickly in the hole/groove is far away from the molten lead, making it difficult for heat to transfer, so it takes time to remelt it and also affects adjacent areas, whereas in case B, It is thought that the once solidified lead was remelted when pulled up.

In the examples (1) and (2) above, a lead coating was formed or not formed by changing the surface morphology of two synthetic resin materials of the same material.
Next, an example will be shown in which the method is carried out between different types of synthetic resins.

(3) Figure 4 is an explanatory diagram of the third embodiment, where A is polypropylene with a diameter of 2 mm, and B is ABS with the same size.
(Acrylic nitrile, butadiene, styrene resin)
It is. These A and B are placed in molten lead at a temperature of 340℃.
When the sample was immersed for 0.4 seconds and pulled up, a lead coating was formed on the sample A, but no coating was formed on the sample B. This is because ABS has a lower melting temperature than polypropylene, so the surface melts quickly and prevents the lead film from adhering to it, whereas polypropylene is pulled up before the surface starts to melt, making it difficult for the lead film to adhere. It is thought that there are.

The relationship between the molten lead temperature and the immersion time required to form a lead film in the above Examples (1), (2), and (3) is shown in FIGS. 5, 6, and 7, respectively.

In Fig. 5, the range surrounded by a solid line is the lead temperature and immersion time for forming a film in A of Fig. 2, and the range surrounded by a dotted line (partially overlapping with the solid line, the same applies hereinafter) is the same as B.
shows the lead temperature and immersion time to form a film.

Similarly, in Figure 6, the range surrounded by a solid line is B
The range surrounded by dotted lines shows the lead temperature and immersion time for forming the respective films in A.

Furthermore, the range surrounded by a solid line in Fig. 7 is A.
The range surrounded by dotted lines shows the lead temperature and immersion time for forming a film on B, respectively.

Combining the above figures 5 to 7, in the three cases, a lead coating is formed only in A, and no coating is formed in B in the range of molten lead temperature and immersion time in the difference area between the solid line area and the dotted line area, that is, area a. It can be done.

Therefore, in Fig. 1b, the blacked out part is made up of A, and the other parts are made up of B, and these A, B
If the immersion method is carried out at a temperature and time in range a corresponding to , it is possible to form a lead film only in the shaded area in FIG.

As explained above, according to the present invention, the amount of lead used in the lead-acid battery electrode grid can be kept to the minimum necessary, contributing to weight reduction, and the effect of contributing to mass production is remarkable.

[Brief explanation of the drawing]

FIG. 1a is a front view of a lead-acid battery plate lattice manufactured by a conventional manufacturing method, FIG. 1b is a front view of a lattice manufactured according to the first embodiment of the present invention, and FIG. FIG. 3 is an explanatory diagram of the second embodiment, FIG. 4 is an explanatory diagram of the third embodiment, and FIGS. 5, 6, and 7 are diagrams of FIGS. FIG. 5 is a diagram showing the molten lead temperature and immersion time necessary for forming a lead film in the case of FIGS.

Claims (1)

[Claims] 1. The surface of the structure is immersed in molten lead or lead alloy, or by pouring molten lead or lead alloy over the structure. 1. A method for manufacturing a lead-acid battery, comprising: an electrode plate grid body on which a lead or lead alloy coating is selectively formed on the surface of the structure by utilizing the adhesion of the lead or lead alloy coating to the lead or lead alloy coating.