SU437565A1 - Centrifugal machine for continuous casting of hollow billets and tubes - Google Patents

Description

one

The invention relates to the field of foundry, in particular to equipment for continuous centrifugal casting.

The known continuous casting machines consist of a casting device, a rotating mold, a reciprocating mechanism of the mold, a mechanism for continuous or periodic stretching, and a cutting mechanism for the cast billets.

In such machines, the process of obtaining suitable, continuously cast billets without cracks or tears is very difficult due to the effect of the mold 1 on the melt and hardening crust of centrifugal forces and tensile stresses arising from continuous or periodic stretching of the workpiece.

The purpose of the invention is to obtain high-quality billets without cracks and fractures and the stability of the continuous casting process.

The essence of the invention is as follows.

To form a high-quality hollow billet and to easily remove the short-circuit of the rotary mold, a new element is used along with the known elements of the machine - a rotating pusher reciprocating in the mold and cyclically ejecting the solidified workpiece from the mold simultaneously with its extrusion.

The drawing shows the described centrifugal machine, a general view.

The machine consists of a filling device 1 with a gas supplying tube, a housing 2, a mold 3, a metal pusher 4, support 5 and drive 6 rollers, an electric drive 7, a periodic stretching mechanism 8, a brake mechanism 9 and actuators of the push-pull mechanism of the pusher, crystallizer and the drive of mechapism of drawing (not shown in the drawing). The mold consists of two parts: a relatively short filling zone (with a length of 2-4 diameters) and a longer secondary cooling zone. In the pouring area, the mold and the workpiece are cooled with water and longitudinal channels formed in the walls of the mold; in the secondary cooling zone - using spatters 10. For the retained-1 workpiece, coaxially with the mold and to prevent cracking in the secondary cooling zone, supporting spring loaded shoes 11 are used, which have openings for the passage of the cooling agent. Collet chuck mechanism 8 has grips-bash, poppies and.

the work makes in the direction of them, located on the tail part of the mold, the reciprocating and accessible movement. A brake mechanism 9 is located on the inner surface of the crystallizer tail, ensuring stopping of the workpiece in exhausting during the return movement of the collet mechanism shoe. The cutting of workpieces in the continuous casting process is carried out using known means of fire or mechanical cutting (shown in the drawing "e").

The machine works as follows.

Before starting casting, the mold cavity is injected into the first half of the mold, the pusher is retracted to the rear extreme position, and the collet mechanism is in the front position and includes the drive of rotation of the core, the pusher and the collet mechanism. Then, protective gas (for example, argon) is fed through the pipe into the стал-cavity of the installer, and liquid metal is poured through a filling device at a constant weight rate. After the expiration of the calculated Burden from the beginning of the pouring, during which the metal crust is formed, a collet, mechanical stretch tension is formed. At the same time, the bashmaks of the collet mechanism seize the bale (or seed in the initial period of pouring) and stretch it by a length equal to the drawing step. At the same time, the pusher pushes the billet with a slight pulling on it. This combined action of the danging mechanism and the pusher allows you to extract the workpiece without the occurrence of dangerous tensile stresses in the metal crust. At the end of each draw cycle, the workpiece is stopped by a brake mechanism, and the pusher and collet mechanism are retracted. In the non-period of stopping in drawing, the mold makes a small translational movement in. side of drawing, ensuring the pressing of the workpiece along its axis. In the future, continuous pouring of the melt into the cavity of the mold, the stretching | Givani cycles are repeated. With reciprocating motion

The pusher rod of the rod 12, rigidly mounted on the pusher, moves in the channels of the mold. In this case, the coaxiality of the pusher with the crystallizer is ensured, the rotational moment is transferred from the crystallizer to the pusher and water cooling of the pusher is carried out according to the scheme; supply manifold 13 - internal channels and the mold-pusher 4 - external channels b

mold - outlet manifold 14 (see drawing). For a better heat sink and to provide intensive cooling of the mold in the pouring zone, internal channels, the number of which should not be

less than 15-20, and only 3-4 of the new stock are present. This number of rods, evened uniformly around the circumference, provides a fairly good centering of the pusher and its intensive cooling with running water;

this improves the condition of the heat sink in the mold. In the internal channels without rods, the cooling water flows from the inlet manifold and is discharged directly into the outlet manifold.

Subject invention

A centrifugal machine for continuous casting of hollow billets and tubes, including a casting device, a rotating mold and a mechanism for non-periodic drawing of the workpiece, a mechanism for reciprocating the mold and

a mechanism for cutting blanks, characterized in that, with the cleavage of the possibility of extracting blanks from the mold without cracks and tears by pressing a moldable workpiece, the mold was replaced by a pusher, made in the form of a cylinder, mounted in the mold coaxially with the embossing device and provided with hollow tracks rods interacting with the corresponding channels formed in the wall of the crystallizer, along which the coolant is passed.

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