JPH07112241A - Metallic mold casting method and apparatus thereof - Google Patents

Abstract

PURPOSE:To provide a metallic mold casting method for steel ingot excellent in the soundness sufficient in yield and improved in productivity. CONSTITUTION:This metallic mold casting apparatus is composed of the metallic mold 2 for producing the ingot, a positional fixing nozzle 13 inserted into the metallic mold from the upper part and arranged with a molten metal pouring hole 4 provided at the lower end part of the bottom surface part in the metallic mold and an elevator device 11 for descending the metallic mold in order to keep a distance (h) between the molten metal pouring hole and the molten metal upper surface in the metallic mold to in the range of 30-50mm at the time of pouring the molten metal from the molten metal pouring hole of the nozzle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal mold casting method and an apparatus therefor, and in particular, can obtain a sound ingot.

[0002]

2. Description of the Related Art Conventionally, billets such as copper-nickel alloys and nickel-base alloys have been produced by die casting or semi-continuous casting except for some alloys. And in view of the soundness of the ingot, the latter is overwhelmingly advantageous,
Recently, the transition to continuous casting has been promoted, but some alloys such as Nichrome alloy and pure nickel are extremely difficult to continuously cast, and the casting structure is weaker than the die cast product. Therefore, there was a problem of cracking in the hot rolling in the subsequent process.

Therefore, the following mold casting method is carried out to manufacture the ingots of these metals. That is, as shown in FIG. 3, the mold (2) is placed directly below the melting furnace (1) for melting metal.
Is installed and the molten metal (3) is directly flowed down from the upper opening of the mold (2), or the molten metal (3) from the melting furnace (1) is transferred to the mold (2) as shown in FIG. There is a down pouring method using an external pouring pipe (5) configured to pour the molten metal into the mold from the tap hole (4) opened at the bottom of the.

[0004]

However, in the above-mentioned top-pouring method, a healthy ingot cannot be obtained because there are many inclusions in the splash or ingot, and in the above-mentioned bottom-pouring method, the yield is poor and the apparatus is complicated. There was a problem of poor productivity.

[0005]

Therefore, as a result of various investigations in view of these problems, the present invention provides a casting method and an apparatus therefor capable of efficiently producing an ingot with little splash or inclusion inclusion by using die casting. It was developed.

That is, the mold casting method of the present invention is a mold casting method in which a molten metal is poured into a mold to produce an ingot, and a tap hole for discharging the molten metal into the mold is provided in the mold. It is installed on the bottom part to start pouring, and then the distance between the molten metal upper surface in the mold and the tap is kept within the range of 30 to 50 mm, and the tap and die are moved up and down relatively. It is characterized by continuously pouring molten metal.

Further, the casting apparatus of the present invention is fixed at a height position in which a die for producing an ingot and a tap hole provided at the bottom end of the die which is inserted from the top into the die and is provided at the bottom of the die are arranged. It consists of a nozzle and an elevator device that lowers the mold in order to keep the distance between the tap and the upper surface of the molten metal in the mold within a range of 30 to 50 mm when the molten metal is discharged from the nozzle discharge port. In this case, it is effective that the lower end surface of the nozzle is closed and a tap hole is provided on the side surface.

[0008]

EXAMPLES The present invention will be further described below with reference to examples.

One example of the device of the present invention is, as shown in FIG. 1, an elevator device in which a motor (10) moves a platen (11) at the upper end up and down by a combination of a rack and a pinion. 2) is placed so that the tap hole (4) at the lower end of the nozzle (13) having a funnel (12) at the upper end fixed independently of the elevator device is located at the bottom of the mold (4). The nozzle (13) is inserted into the mold.

In order to carry out the method of the present invention using the above casting apparatus, first, a molten metal is prepared in the melting furnace (1) directly above the mold (2), and the melting furnace (1) is tilted to form the molten metal. Funnel (12)
The molten metal flows through the nozzle (13) and comes out from the lower end tap (4) and starts to accumulate in the mold (2). And the difference (h) in height between the molten metal upper surface in the mold and the tap hole (4)
Platen (11) when it reaches a predetermined value between 30 and 50 mm
To descend at a constant speed. This descent rate is always h
The value should be commensurate with the amount of molten metal supplied so that it lies between 30 and 50 mm.

According to the method of the present invention, the quality of the ingot obtained is extremely superior to that of the conventional product. At the start of casting, the molten metal should fall at a rate corresponding to the height H from the funnel (12) to the bottom surface of the mold as in the conventional top-pouring method. Due to the frictional resistance of the inner surface of the passing nozzle (13), the falling speed of the molten metal is greatly reduced, and therefore, there is an advantage that splash is hardly generated even at the start.

Further, as shown in FIG. 2, when the lower end surface of the nozzle is closed and the tap hole (4) is provided on the side surface of the nozzle (13), the molten metal is discharged in the lateral direction, so that the above effect is further enhanced.
Further, in order to keep h constant in FIG. 1, the platen (11)
A weight sensor (14) such as a resistance strain gauge is provided inside the motor (1) according to the rate of change of weight by the sensor (14).
A good method is to automatically control 0) to adjust the descending speed of the platen (11).

Further, in this embodiment, the mold is lowered by using the elevator device, but the mold may be fixed and the nozzle may be raised.

Casting tests of various metals were carried out by the apparatus shown in FIG. That is, the various metals shown in Table 1 were melted using a 20 kg atmospheric melting furnace and cast by the conventional top-pouring die casting method shown in FIG. 3 and the die casting method of the present invention shown in FIG. The soundness was comparatively investigated. The size of the ingot is φ85mm × L
It was 400 mm, and the survey results are also shown in Table 1. Further, in the apparatus of the present invention, the platen descending speed was set to 10 mm / sec, and the height h between the lower end tap of the nozzle and the upper surface of the molten metal was maintained at about 40 mm.

[0015]

[Table 1]

It can be seen from Table 1 that the ingot produced by the method of the present invention has fewer defects and a better yield than the conventional ingot.

[0017]

As described above, according to the present invention, the soundness of the ingot obtained by die casting is excellent, the yield is good, and the apparatus is not complicated, so that the productivity can be improved. Has a great effect.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a device of the present invention.

FIG. 2 is an explanatory view of a main part of another example of the device of the present invention.

FIG. 3 is an explanatory diagram showing a conventional example.

FIG. 4 is an explanatory diagram showing another conventional example.

[Explanation of symbols]

 1 Melting furnace 2 Mold 3 Metal melt 4 Outlet port 5 External pouring pipe 10 Motor 11 Platen 12 Funnel 13 Nozzle

Claims (3)

[Claims] 1. In a die casting method for producing molten metal by pouring molten metal into a die, a pouring port for pouring the molten metal into the die is provided on the bottom surface of the die. After that, the distance between the molten metal upper surface in the mold and the tap hole is kept within the range of 30 to 50 mm, and the tap hole and the die are moved relatively up and down to continuously perform pouring. A mold casting method characterized in that 2. A mold for producing an ingot, a nozzle fixed at a height position, in which a tap hole is provided from the top into the mold and provided at the bottom end of the bottom surface of the inside of the mold. When the molten metal is discharged from the mold, the mold comprises an elevator device for lowering the mold so as to keep the distance between the discharge port and the upper surface of the molten metal in the mold within a range of 30 to 50 mm. Mold casting equipment. 3. The mold casting apparatus according to claim 2, wherein the lower end surface of the nozzle is closed and a tap hole is provided on the side surface.