RU2570138C1 - Pouring gate system for centrifugal shaped casting with vertical axis of rotation - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to production of thick wall castings with wall thickness 2.5-3.5 mm, diameter over 1000 mm out of titanium and heat-resistant alloys, with ring surfaces 8 at different distances from axis, and connected with each other by radial fins 9. The pouring gate system contains a cylindrical central riser 2, in bottom part having square shape, horizontal pouring channels 4 located at square corners. The pouring channels 4 are deviated by angle 30°C towards rotation and have sectorial pouring channels 5 located along concentric circles, that are connected with the vertical feeders 6. Increased quality of thin wall products is ensured due to quiet flow of the melt along the circle upon entrance to the thin wall part of the mould, without vortex and torsion.

EFFECT: pouring gate system has high throughput capacity and compact dimensions.

3 dwg

Description

Technical field

The invention relates to the field of metallurgy, in particular, to a method for producing thin-walled castings of large diameters, for example, from titanium and heat-resistant alloys with annular surfaces differently spaced from the axis, interconnected by radial elements, cast by a centrifugal method with a vertical axis of rotation.

State of the art

Closest to the invention are the patents for "Method for the manufacture of ring castings from titanium titanium alloys" No. 2283206, No. 2151027, No. 2058849.

Known sprue system containing a central riser with an expanding lower part, a divider with blades made with variable curvature, and sprue passages connected to forms by feeders (Moiseev B.C. and other RF Patent No. 2058849, 04/27/1996). The indicated configuration of the gating system due to the use of deaf, not communicating volumes formed by the blades, significantly reduces the slipping of the melt in the metal receiver, increasing the throughput of the gating system. However, the positive effect of this method does not extend to the transfer of the melt to the inner annular surfaces of the castings, the filling of which obeys only the laws of centrifugal forces. This does not take into account the dependence on the direction of rotation and the distance from the axis of rotation to the point of entry of the metal into the body of the casting.

Disclosure of invention

The aim of the invention is the development of methods for supplying metal to various areas of castings to ensure sufficient supply of thin-walled elements and preserve the continuity of the flow to obtain high-quality casting material in all sections.

The problem was achieved in that in the proposed gating system for centrifugal shaped casting with a vertical axis of rotation for thin-walled castings of large diameters, for example, from titanium and heat-resistant alloys with annular surfaces different from the axis, interconnected by radial elements containing a cylindrical central riser (metal receiver ) and the gateways connected to the feeders, according to the invention, the lower part of the central riser is made in the form of a square with an angled outlet for forced capture of the metal and displacement of the axis relative to the axis of rotation of the mold, and the metal is fed into the ring parts (into the body) of the casting with a gap from the feeders located along sectoral ring circles, rotated in the direction of rotation by an angle of 30 °, connected to the central riser by narrowing gate .

The technical result achieved by the invention is to improve the quality of thin-walled castings of large diameters by ensuring a smooth flow of the melt stream around the circumference at the entrance to the thin-walled part of the mold in pressure mode, without swirling and inversion. At the same time, the gating system has a high throughput and compact dimensions.

The technical result is achieved as follows.

The gating system for centrifugal shaped casting with a vertical axis of rotation for thin-walled castings of large diameter with annular surfaces differently spaced from the axis, interconnected by radial elements, containing a cylindrical central riser (metal receptacle), horizontal gate ways, feeders, while the central riser in the lower part is made square shape, and the horizontal gateways are placed at the corners of the square, deflected at an angle of 30 ° in the direction of rotation and equipped with sectoral sprues passages located on circular circles connected to vertical feeders.

The invention is illustrated by drawings. In FIG. 1 shows a sectional diagram of a casting in a pouring container, where: 1 is a container; 2 - the central riser (metal receiver); 3 - casting in the form of centric circles connected by knitting needles or blades; 4 - horizontal gate (4 pcs.); 5 - sectoral sprue course (12 pcs.); 6 - vertical feeder (36 pcs.).

In FIG. 2 shows the construction of the sprue system without casting, side view and top view, where: 2 - the central riser with a square lower part (Fig. 3); 4 - horizontal runway; 5 - sectoral sprue course; 6 - vertical feeder. The places of sections S1, S2, S3 are indicated. S1 is the cross-sectional area of the metal in the casting funnel. S2 is the cross-sectional area at the outlet of the central metal of the receiver. S3 is the total area of the feeders at the entrance to the casting. The direction of rotation of the form with the arrow and the angle of rotation in the direction of rotation by 30 °.

In FIG. 4 shows a cross-section of the square part of the riser with an angular exit of metal, the direction of rotation of the mold and the direction of sectoral gateways.

SUMMARY OF THE INVENTION

The basis of the invention is a method for pouring thin-walled castings of large diameters (Fig. 1), consisting of several differently spaced annular surfaces interconnected by radial ribs (blades). The gating system designed to produce castings (3) consists of (1) a pouring container, (2) a riser, (4) a horizontal gate, (5) a sector horizontal gate, (6) a feeder.

The essence of the invention lies in the fact that the proposed method of supplying metal (Fig. 2) when pouring thin-walled castings of large diameters ensures uniform filling of the mold due to the constant pressure of the melt, excluding spatter and rupture of the metal during its movement.

Uneven filling of the mold, spraying of the melt of alloys with low casting properties (in particular titanium and heat-resistant alloys) is due to the fact that at the first moment of the melt entering the rotating riser, the liquid metal acquires an angular velocity, which causes it to slip.

The rationale for the proposed gate system (a method of supplying metal to the casting) is given below.

The compact square shape of the riser in the lower part (Fig. 3 and 4) eliminates the slipping of the melt at the moment of the beginning of the movement and eliminates splashing. The angular arrangement of horizontal gateways provides maximum flow rate and forced metal grip. The minimum metal slippage at the first moment of the melt entering the rotating mold is achieved by shifting the horizontal gate gates of the metal into the corner zones of the square section and turning the horizontal gate gates by an angle of 30 ° in the direction of rotation of the mold, which allows filling the corner parts of the section. Further, the metal, under the action of centrifugal forces directed radially from the center, tends to the periphery, while moving along the rear wall of the horizontal channel, the rotation of which prevents the flow from breaking. This continues until the horizontal part of the gate system is filled, including sectoral gate courses (located along concentric circles). The metal is fed into the body of the casting by vertical feeders, made with a gap, to ensure uniform distribution of metal along the diameter of the casting. At the same time, the lower melt supply ensures the maximum capacity of the metal receiver at the time of discharge and the continuity of the flow, and the metal is fed into the casting body along ring feeders with a certain step, depending on the radius and evenly distributing the metal around the circumference into thin parts of the casting.

A similar minimum spray of the melt can be realized in a hexagonal riser fan type. However, the compact dimensions of the riser with a square base provides minimal metal consumption of the gating system.

A necessary condition for the continuity of the melt flow is to ensure the size ratio of the gating system (Fig. 1): S1: S2: S3 = 1.04: 1: (3-5), where S1 is the cross-sectional area of the casting funnel or tray, S2 is the total the cross-sectional area of the horizontal gate runs at the exit of the central riser, S3 is the total area of feeders at the entrance to the casting body.

Claims (1)

The gating system for centrifugal shaped casting with a vertical axis of rotation of large-diameter thin-walled castings with annular surfaces differently spaced from the axis, interconnected by radial elements, containing a cylindrical central riser, horizontal gateways, feeders, while the central riser in the lower part is square in shape, and horizontal gateways are placed at the corners of the square, deflected at an angle of 30 ° in the direction of rotation and equipped with sectoral gateways, located GOVERNMENTAL in concentric circles, connected with vertical feeders.

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