JPH09276991A - Mold for producing ingot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the long service life of a mold and to reduce the producing cost of the ingot by making at least an inner mold with a cast iron, in the mold for producing the ingot constituted with an outer mold and the inner mold and circulating coolant into gap between the ouer mold and the inner mold. SOLUTION: The mold for producing the ingot is constituted with the inner mold recessed as reverse trapezoidal shape in the cross section and the box type outer mold joined by bolts with the outer periphery of the inner mold at the upper end part, and to the outer mold, nozzle for circulating the coolant is fitted. The inner mold is made of the cast iron. By this structure, the residual stress at the bending parts in the inner mold is eliminated and the development of the crack, etc., caused by the residual stress can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for casting metal, and more particularly to a mold for producing zinc alloy.

[0002]

2. Description of the Related Art A zinc alloy used for hot dip galvanizing combines zinc with a desired amount of aluminum or lead,
Uniformly melt in a low-frequency induction furnace, etc., temperature 500-600 ℃
It is poured into a mold with a mold, and manufactured as an ingot of 500 to 2000 kg, and is commercially available. Usually, in this casting, a water-cooled mold is used to improve productivity.

[0003]

The zinc alloy ingot used for hot dip galvanizing is required to have smooth surfaces on the structure of the plating equipment used. Therefore, the mold is made by press forming a steel plate. However, in the mold produced by press molding, stress is concentrated in the bent portion, and therefore, when used 1500 to 2000 times, cracks are generated in the bent portion, cooling water leaks, and cannot be used.

This mold is expensive, and it accounts for a large proportion of the zinc alloy ingot manufacturing cost, and it has been desired to extend the life of the mold.

[0005]

Means for Solving the Problems As a result of various investigations, the inventors of the present invention have found that if a cast iron which has not been conventionally used as a material for a zinc alloy mold is used and a mold is produced by precision casting, It was found that it is possible to produce a zinc alloy ingot of similar quality, and the present invention has been completed.

[0006] That is, the mold of the present invention for solving the above-mentioned problems is composed of an outer mold and an inner mold, and is a mold for ingot production in which a refrigerant can flow between the outer mold and the inner mold. In the above, at least the inner mold is made of cast iron. This mold is particularly effective for zinc alloys.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a top view of an inner mold of one example of the present invention, FIG. 2 shows its AA sectional view, and FIG. 3 shows its CC sectional view. Then, FIG. 4 shows a top view of the outer die, FIG. 5 shows a sectional view taken along line AA, and FIG. 6 shows a sectional view taken along line CC.

The mold of the present invention is composed of an inner mold which is recessed in an inverted trapezoidal cross section, and a box-shaped outer mold whose upper end is joined to the outer periphery of the inner mold by bolting. A nozzle 1 is attached to allow the cooling solvent to flow through.

What is essential in the mold of the present invention is that at least the inner mold is made of cast iron. By doing so, the residual stress in the bent portion of the inner mold is eliminated, and it is possible to prevent the occurrence of cracks and the like due to the residual stress.

Whether cast iron is used as the outer mold is determined not by the durability of the mold itself but by the manufacturing cost of the mold.

Five molds of the present invention (cast iron products 1 to 5 in Table 1) were prepared using an inner mold having a thickness of 50 mm like the mold manufactured by conventional press molding. A comparative test was performed using this mold and a conventional steel plate mold (steel plates 1 to 5 in Table 1). As a comparison condition, 0.5 at 550 ° C.
% Of zinc alloy containing aluminum was poured into each mold, and the number of times of casting until the water leakage could be confirmed from the mold was determined. In addition, cooling water at the time of casting was made to flow through at a rate of 350 liters / minute by connecting the respective molds in series.

The results obtained are shown in Table 1.

[0013] From the results of Table 1, it was found that the cast iron mold of the present invention withstands use of 3000 to 4000 times, whereas the conventional steel plate mold could be used less than 2000 times.

[0014]

As described above, in the mold of the present invention,
Since unnecessary residual stress does not occur during mold production, the life is extended, and as a result, the ingot manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a top view of an example of an inner mold of a mold of the present invention.

2 is a cross-sectional view taken along the line AA of the mold of FIG.

FIG. 3 is a cross-sectional view taken along the line BB of the mold of FIG.

FIG. 4 is a top view of an example of the outer mold of the mold of the present invention.

5 is a cross-sectional view taken along the line AA of the mold of FIG.

6 is a cross-sectional view taken along the line BB of the mold of FIG.

Claims (2)

[Claims] 1. A mold for ingot production, comprising an outer mold and an inner mold, wherein a coolant can flow between the outer mold and the inner mold, wherein at least the inner mold is made of cast iron. A mold for ingot production. 2. The mold according to claim 1, which is for a zinc alloy.