US3460608A

US3460608A - Vacuum induction casting plant without crucible

Info

Publication number: US3460608A
Application number: US531980A
Authority: US
Inventors: Vyacheslav Petrovich Grechin; Zakhar Alexeevich Oreshnikov; Boris Fedorovich Milyaev
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-03-04
Filing date: 1966-03-04
Publication date: 1969-08-12
Anticipated expiration: 1986-08-12
Also published as: GB1128484A

Description

Aug. 12, 1969 v, GREG-N ETAL 3,460,608

VACUUM INDUCTION CASTING PLANT WITHOUT CRUCIBLE Filed March 4, 1966 IV////// /////////////////)/fl///////l United States Patent 3,460,608 VACUUM INDUCTION CASTING PLANT WITHOUT CRUCIBLE Vyacheslav Petrovich Grechin, Kutuzovsky prospekt 8, kv. 37; Zakllar Alexeevich Oreshmkov, Otkrytoe shosse 21, korpus 2, kv. 7; and Boris Fedorovlch Mrlyaev, Izmarlovsky Prospekt 117/1, kv. 17, all of Moscow, USSR.

Filed Mar. 4, 1966, Ser. No. 531,980 Int. Cl. B22d 27/02, 27/16 US. Cl. 164-251 3 Claims ABSTRACT OF THE DISCLOSURE A plant for producing castings by melting billets in which the billets are charged into chambers WhlCh are evacuated whereafter the billets from the chambers are supplied to respective heating means in a vacuum chamber in sequence and therein melted and deposited as a continuous stream into a mold.

The present invention relates to apparatus for melting metal, and more particularly to vacuum lnduction plants without crucible for making ingots and castings of metal obtained by melting billets.

Known in the art are vacuum induction plants for making castings of billets, said plants being provided with an inductor for melting a billet without the use of a crucible and a mold for the molten metal. I

In these plants, upon melting a billet supplied into the melting inductor, the stream of molten metal is interrupted until the following billet is supplied into the inductor. With such a melting procedure, it is difficult to obtain quality ingots of large weight.

As to the use of starting billets of a greater length and diameter, this is impracticable on account of the difficulties involved in the production of such billets, especially of a difficult-to-machine metal.

An object of the present invention is to provide such a vacuum induction plant without crucible which enables the manufacture of quality castings of large weight from metal obtained by melting down small billets without interrupting the stream of metal.

According to this and other objects, the proposed vacuum induction plant without crucible, according to the invention, employs a plurality of melting inductors opcrating either alternately or simultaneously. The receiving chamber of the plant is preferably constructed as a plurality of sections the number of which corresponds to the number of melting inductors.

One of the possible embodiments of the proposed plant for making ingots and castings from metal obtained by melting down billets is represented partially in section in the sole figure of the attached drawing.

The vacuum induction plant without crucible is comprised of three essential parts, namely: a melting chamber 1, chambers 2 for charging billets, and a chamber 3 for discharging an ingot or a cast piece.

The melting chamber 1 accommodates three melting inductors 4 supplied with electric current from high-frequency generators. An additional inductor 5, supplied from the industrial mains, is employed for preheating a mold 6 to mix preheat the molten metal contained in the mold. The chambers 2 for charging billets are constituted as three separate sections (according to the number of melting inductors) connected with the melting chamber 1 by means of three vacuum locks 7 (the drawing shows but one vacuum lock). Each section is essentially a receiver, into which can be simultaneously charged a plurality of billets according to their size and diameter. The billets 8 are charged into sections through doors 9.

Three mechanisms 10 are employed to effect the automatic supply of the billets 8 into the melting inductors 4.

The discharging chamber 3 is isolated from the melting chamber 1 by means of a vacuum lock 11. This chamber accommodates a mechanism 12 for lifting and lowering the mold 6. In the case where an ingot is to be cast into a water-cooled mold, the mechanism 12 functions as a means for extracting the ingot. The ingot or the molds are discharged from the chamber 3 through a door 13.

The vacuum plant of the invention operates as follows:

Each operation is started by lowering the mold 6, by means of the mechanism 12, into the discharging chamber 3. A casting is removed from the mold and the latter is then raised into the melting chamber. Then, the billets 8 to be melted are charged into the chamber 2. Afterwards, the doors 9 and 13 are closed, and the air is evacuated from the plant until a residual pressure squal to 1 to 3 microns of mercury is obtained. Simultaneously, the neXt billet is supplied into one of the melting inductors 4; the metal melts and pours into the mold 6. Upon melting down of the first billet, the next melting inductor with a new billet is started, and the process of melting thus continues. At the same time, the first melting inductor is prepared for the next heat, which is brought about by supplying the following billet into it.

As a result of the consecutive melting of billets supplied into the corresponding melting inductors, the metal is poured in a continuous stream into the mold.

In the course of the heating, it is permissible for the vacuum in one of the chambers 2 to be disturbed, so that it can be charged with new billets. As soon as the air is evacuated from this chamber, it becomes ready for the continuation of operation.

Thus, the proposed vacuum induction plant can operate continuously for a practically unlimited period of time.

In case where it is required to pour into the mold a large volume of metal at once for the manufacture of a complicated casting or for making an ingot of a large section, all the melting inductors 4 may be operated simutaneously. For this purpose, the billets are supplied into all the inductors, and the molten metal thus obtained is poured into the mold 6.

What is claimed is:

1. A plant for producing castings by melting metal prefabricated billets, said plant comprising: a vacuum chamber; melting means accommodated in said vacuum chamber, a mold for molten metal in said vacuum chamber; a plurality of hermetically-sealed chambers mounted above said vac-uum chamber each including receiving means for accommodating billets to be melted; vacuum lock means connecting each said hermetically-sealed chamber and said vacuum chamber such that the hermeticallysealed chambers can be selectively isolated from the vacuum chamber; means for transferring the billets from the hermetically-sealed chambers through a respective vacuum lock means into said melting means in said vacuum chamber, said melting means being positioned above said mold whereby molten metal from the melting means is deposited into the mold and a finished ingot is cast in said mold, and means for discharging finished ingots from said vacuum chamber.

2. A plant as claimed in claim 1, wherein a separate melting means is provided in said vacuum chamber for each hermetically-sealed chamber.

3. A plant as claimed in claim 2, wherein said vacuum lock means is operative to isolate successive receiver means from the vacuum chamber to enable their supply with billets while the other receiver means continue to 3 supply billets to their respective heating means whereby continuous supply of molten material to the mold is effected.

References Cited UNITED STATES PATENTS 2,445,670 7/1948 Hopkins 164-252 2,686,864 8/1954 Wroughton et al. 164-65 XR 2,818,461 12/1957 Gruber et a1. 164-252 XR 4 3,014,255 12/1961 Bussard et a1. 164251 XR 3,234,608 2/1966 Peras l6452 3,226,102 12/1965 Pagonis 16465 X J. SPENCER OVERHOLSER, Primary Examiner R. SPENCER ANNEAR, Assistant Examiner US. Cl. X.R. 16465, 258