JPH0377749A - Casting apparatus for lead alloy continuous grid - Google Patents

Abstract

PURPOSE:To obtain a grid without cutting ladders by producing lead alloy- continuously cast grid having band shaped network body with joint part of small cross sectional area at every specified intervals. CONSTITUTION:By using one pair of band shaped molds 1, 2 rotating in mutually reverse direction and endlessly shifting, molten lead alloy is poured into the part of zone where the molds are moved in close contact with each other and the temp. is raised by heating. After that, this is cooled with cooling mechanisms 10a, 10b to draw out the lead alloy-continuously cast grid 11 having band shaped network body. In this network body 11, the joint parts 12a, 12b, 12c having small cross sectional area to the horizontal direction at the specified interval are arranged in the vertical direction and earings 13a, 13b are projectingly arranged at lower part between the joint parts and the excess lead alloy zone 14 exists at the upper part thereof but this lead alloy 14 is cut off with a slitter 15.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a casting apparatus for a continuous grid of lead alloys used for electrode plates of lead batteries.

Conventional technology and its challenges Conventional continuous lead alloy grids include expanded grids, which are made by cutting a lead alloy sheet and inserting zero tubes, and pouring molten lead alloy into a rotating cooling drum with mesh grooves. and cool,
Solidified drum type series I! There is a latticework.

In the former method, a lead alloy sheet must be manufactured in advance by rolling or continuous casting, but the yield rate of the sheet is low and it is expensive because the lattice ears are formed during expansion, and the electrical resistance is low because the lattice bars are arranged in a zigzag pattern. It had the disadvantage of being large.

The latter is cooled from the rotating drum surface and has a structure in which the crystals on the lattice bars grow in one direction from the drum surface, which tends to cause intergranular corrosion, and it is difficult to balance the speeds of solidification and pouring on the rotating drum surface. It had the disadvantage of being prone to breakage and burrs.

FIG. 4 shows the crystal plasticity of a conventional drum-type cast lattice. The left side of the figure shows a structure that is rapidly formed on the drum surface, with crystals growing inside from the drum surface in a columnar manner. On the right is the tissue that was annealed on the opposite side.

Means for Solving the Problems The present invention uses a pair of belt-shaped molds that rotate in opposite directions and move endlessly, and the molten lead alloy is heated in the heated zone where the molds move closely together. Pour hot water,
After that, it is cooled and becomes a continuous lead alloy, which is a band-like network with small cross-sectional areas at regular intervals. The above-mentioned drawbacks are solved by using the lfl lattice as the entire lattice. FIG. 5 shows the crystal composition of the continuous gun lattice according to the present invention, and the mesh body has an irregular structure uniformly cooled from the entire circumference.

Example The present invention will be explained using preferred embodiments.

FIG. 1 is a diagram showing an embodiment of a lead alloy continuous molding device using a strip-shaped mold. 1 and 2 are a pair of belt-shaped molds that move approximately horizontally at the same speed for one revolution, and between zones 3 and 4 where they move closely together, a mesh groove that opens upward is formed between the molds. be done. A structure 5a and 5b, 6 which press the mold from the outside measurement of a pair of band-shaped molds in this zone.
There are a and 6b and 7a and 7b. 8 is a pouring am of molten lead alloy, which pours molten lead alloy such as lead-calcium alloy or lead-antimony alloy, which is commonly used for grids for lead-acid batteries, into the upper opening connected to the mesh grooves of a pair of band-shaped molds. The pouring mechanisms 9A and 9b for pouring molten metal are provided in the vicinity of the lead alloy pouring part in the strip mold with heating a-ovals, and heat the mold in the vicinity of the pouring part. As the heating method, commonly used means such as electric heat, steam, gas, and infrared rays can be used.

10^ and 10b are cooling mechanisms that cool the strip mold after the lead alloy pouring section. As the cooling method, commonly used means such as water cooling and air cooling can be used.

The solidification temperature of lead alloys is approximately 320°C for lead-calcium systems and approximately 250°C for lead-antimony systems, but it is desirable for lead alloys to have a solidification temperature of 450 to 350°C during pouring. The temperature is preferably close to the solidification temperature of the lead alloy, i.e., 280 to 330°C for lead-calcium alloys and 210 to 260°C for lead-antimony alloys. This has the effect of lowering the cooling rate so that the lead alloy is thoroughly filled into the mesh grooves of the strip mold.

This molten metal is cooled and solidified in the next zone, but at this time it is important that it is cooled at a substantially uniform rate from the entire circumference of the mold wall forming the mesh grooves.

As shown in Figure 5, this has the effect of making the crystal structure of the lead alloy irregular and fine, resulting in a lattice with excellent corrosion resistance. What used to be inferior in corrosion resistance due to its elongated structure has been fundamentally improved.

The pair of band-shaped molds rotate and move in opposite directions to separate from each other at a point 4, and the solidified lead alloy band-shaped mesh body 11 is drawn out. This mesh body 11 has joints 12a having a small cross-sectional area in the horizontal direction at regular intervals.

12b, 12c are provided in the vertical direction, ears 13a, 13b are provided protruding downward between the joints, and there is an extra lead alloy band 14 at the top.
This lead alloy 14 is cut off by a slitter 15.

In a zone where band-shaped molds move closely together, mesh grooves opening upward are formed between the molds, and grooves and recesses corresponding to joints and lattice ears are formed. Of course. The joint is important for preventing the molten lead alloy from moving horizontally within the strip mold.

This is necessary in order to thoroughly fill the mesh grooves with the molten metal.

Apply cork powder to the mesh grooves and lattice ears according to the usual method.
It is desirable to apply a mold release agent such as water glass, carbon, talc powder, etc., but if the temperature of the strip mold is kept sufficiently close to, but above, the solidification temperature of the lead alloy, mold release The agent can also be omitted.

The strip molds 1 and 2 are preferably a series of flexible metal plates or one or more grids connected to each other, and this is for the purpose of endlessly moving the strip molds one rotation. This is because it is necessary to bend the mold according to the curvature. At least one of the two band-shaped molds has a mesh groove formed on one side of the mold by engraving or pressing.

Although block-shaped molds within the same thickness may be connected, there is a limit to the wall thickness in order to increase the heating and cooling speed.

Pressing the strip mold @ f45a, 5b, 6a,
6b, 7a, and 7b are necessary in order to reliably form the mesh groove between the molds, but they can also have the function of providing a driving force for moving the band-shaped mold.

The strip-shaped continuous lattice produced as described above is aged if necessary by heating and standing, and then filled with paste and cut according to a conventional method to become an unformed electrode plate. When filling the paste, a thin, loosely textured paper, nonwoven fabric, or glass mat can be brought into contact with or adhered to the electrode plate surface. Note that the strip-shaped continuous lattice can also be cut into individual lattices.

Effects of the Invention The grid obtained by the present invention and the lead-acid battery using the same have the following effects.

(1) Since the molten metal is poured into the mold at a high temperature close to the solidification temperature, the molten lead alloy can be filled seamlessly into the mesh grooves in the mold. Therefore, a grid with no gaps can be obtained.

(2) Since the joints with a small IN area are arranged vertically at regular intervals, it is possible to fill the lower mold of the pouring section with molten metal without interruption.

(3) There is an extra space at the top of the mesh groove that will be cut out later, and the molten metal can be stored here, so the mesh groove can be filled without interruption.
Since the upper part with many casting cavities is removed, a lattice without casting defects can be obtained.

(4) Even if the mesh grooves in (1) to (3) above are made thinner, the molten lead alloy can be filled without interruption, so a thin and lightweight continuous mesh lattice can be obtained.

(5) The molten lead alloy filled in the 1/4 mesh is cooled almost uniformly from the surrounding mold surface and solidified.
A lattice with fine crystal grains and good corrosion resistance can be obtained.

(6) Since the lattice lugs are located at the lowermost end and the molten lead alloy having a large specific gravity can be filled most densely at the bottom, there are no defects in the lattice lugs.

[Brief explanation of drawings]

FIG. 1 is a top view of a lead alloy continuous molding device using a strip-shaped mold, FIG. 2 is a vertical cross-sectional view of the main part of the device, and FIG. 3 is a strip-like mesh body manufactured by the device. FIG. 4 is a diagram (microscopic photograph) showing the alloy composition of a conventional drum-type continuous casting grid, and FIG. 5 is a diagram (microscopic photograph) showing the alloy composition of the lattice obtained according to the present invention. 1.2... Band-shaped molds 5a, 5b, 6a, 6b, 7a, 7b-@Press the mold! i Oval 9a, 9b...Heating mechanism, 10a, 1
0b...Cooling mechanism 12a, 12b, 12c...Joint part 1 Rumor 2

Claims (1)

[Scope of Claims] 1. In a pair of band-shaped molds that move and rotate almost horizontally at the same speed, there is a band that moves closely so as to form a mesh groove opening upward between the molds, In this zone, there is a mechanism for pressing from the outside of a pair of band-shaped molds, a mechanism for pouring molten lead alloy into an upper opening connected to the mesh grooves,
The belt-shaped mold has a heating mechanism near the lead alloy pouring part and a cooling mechanism after pouring, and joints having a small cross-sectional area with respect to the horizontal direction are formed in the mesh groove at regular intervals in the vertical direction. The upper part of the strip-shaped lead alloy mesh body has vertical seams pulled out from the separation part of the strip mold and lattice ears protruding downward between the seams at predetermined intervals. 1. A lead alloy continuous lattice casting device using a pair of belt-shaped molds that rotate in opposite directions and move endlessly, characterized by having a mechanism for cutting out solidified portions. 2. The lead alloy continuous grid casting apparatus according to claim 1, wherein the temperature of the strip mold in the lead alloy pouring part is close to the solidification temperature of the lead alloy, and the lead alloy mesh body is cooled at a substantially uniform rate from the entire circumference. .