RU2333072C2 - Device for casting with crystallisation under pressure - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: device contains crucible in the form of sleeve, which is installed at the bottom table, and container with ceramic form, which is fixed at the top table. Metal cartridge is installed in crucible with gap. Gap between cartridge and crucible is filled with heat insulation material. Pressing piston is fixed in the cartridge cavity with the possibility of displacement. Piston is shaped in the form of hollow metal cartridge, the cavity of which is filled with heat insulation layer made of core sand.

EFFECT: simplification of container design and reduction of ceramic forms pouring technological cycle duration.

2 cl, 1 dwg

Description

The invention relates to foundry, in particular to ceramic molding with crystallization under pressure.

A well-known investment casting machine with crystallization under pressure (LVMKD) (see Information Leaflet No. 20-90 of Novosibirsk Central Scientific Technical Research Institute), consisting of an all-welded bed, a pump station, a hydraulic cylinder, a fixed table for installing a container with a shape of a LVM, a movable table with a metal receiver , electrical cabinet and remote control.

The disadvantages of the device include:

- the need to install the punch on the surface of the liquid metal before filling out the form;

- for each filling, a new cladding of the punch and the metal receiver is required;

- the design of the container of cylindrical shape limits the dimensions and metal consumption of ceramic forms.

The closest technical solution (prototype) is a device for injection molding with crystallization under pressure (see RF patent No. 21116865, IPC B22D 18/02), containing a metal receiver mounted on the lower table, a container with a ceramic form fixed on the upper table, while the metal receiver is made in the form of a base and a removable cup, between the bottom of which and the bottom of the base there is a heat-insulating layer of refractory material, and the container is made of a body, a lid and a neck with a connector at the base of the neck, while on the lid Execute the protrusion around the perimeter body cavity of the cup body and the bottom hearth base is provided with holes for the gas outlet, and is installed on the container neck support ring, having a slope on an outer surface.

The device solves the problem of increasing the metal consumption of casting molds, that is, it partially reduces the duration of casting of the finished alloy and provides ease of pouring, but has a number of significant drawbacks, the main of which is the length of the mold casting cycle, a significant proportion of which is installing a removable nozzle in the base of the metal receiver before casting, checking the alignment of the neck of the container with the cavity of the metal receiver and removing the removable glass from the base of the metal receiver.

The technical task is to increase the efficiency of the device for casting with crystallization under pressure.

The problem is solved in that in a device for injection molding with crystallization under pressure, containing a metal receiver mounted on the lower table in the form of a glass, a container with a shell shape fixed on the upper table, made of a body and a detachable lid with a neck, a metal sleeve is installed inside the metal receiver, the cavity of which is movably fixed with a hollow pressing piston, the cavity of which is filled with a heat-insulating layer.

The invention is illustrated by the drawing, which shows a device for casting with crystallization under pressure.

The device comprises a base 1 from an all-welded bed on which hydraulic cylinders 2 and 3 of lifting and returning to the initial position of the lower table 4 are fixed with a metal receiver 5 and a pressing hydraulic cylinder 6 connected via a rod 7 to a pressing piston 8 made in the form of a hollow cast iron or steel cup, the cavity of which is filled with a heat-insulating layer 9 of the core mixture. The pressing piston 8 is mounted inside the metal receiver 5, which is a cup 11 and a steel or cast-iron sleeve 12 installed therein with a gap, the gap being filled with heat-insulating refractory material 13. The heat-insulating layers 9, 13 provide the necessary metal temperature before filling the mold and favorable conditions for power supply castings.

The base 1 is connected to the upper table 14 by two vertical racks 15. On the upper table 14 there is fixed a container consisting of a housing 16, a flange made around the perimeter, and a cover 17. A ceramic mold 18 is placed in the container, molded by supporting filler 19. In the bottom of the housing of the container 16, a filling hole 20 is made coaxially to the riser 21 of the ceramic mold 18 and the cavity of the metal receiver 5.

The device operates as follows. The ceramic mold 18 is installed in the container body 16 with the riser 21 downward aligned with the filling hole 20 and is molded with a support filler 19, for example fireclay chips, under the influence of vibration. Then, the container body 16 is closed by a lid 17 and fixed on the upper table 14. The device is ready for the start of the pouring process. Liquid metal is poured into the metal receiver 5 about 30 mm below its upper level and the lower table is lifted 4 by the hydraulic cylinders 2 and 3 until the end surface of the metal receiver 5 flange closes with the bottom of the container body 16. Then the pressing hydraulic cylinder 6 is turned on, the pressing piston 8 of which displaces the melt from the metal receiver into the ceramic mold 18 and maintains pressure on the remainder of the molten metal until the casting solidifies. The pressostat solidifies at the same time, but in the center its metal remains in a solid-liquid state. After the casting has hardened, the hydraulic cylinders 6, 2, 3 are turned back on and the pressing piston 8 is returned to its initial position, and then the lower table 4, respectively. When the lower table 4 moves downward, the pressostat is torn off from the riser 21 of the ceramic mold 18. Then, the pressingostat of the metal in the metal receptacle 5 is affected by the pressing piston 8, removed, and the latter is returned to its original position. At the same time, a container filled with ceramic mold 18 is removed from the upper table 14. After installation of the next container on the upper table 14, the casting process is repeated again.

The presence of a pressing piston installed in a steel or cast-iron sleeve in the metal receiver allows to reduce the duration of the technological cycle of pouring ceramic molds, reduce the riser height, reduce the cost of preparing the metal receiver and container with a ceramic mold for pouring and simplify the design of the container.

Claims (2)

1. A device for casting with crystallization under pressure, containing a metal receiver in the form of a cup mounted on the lower table, a container with a ceramic shape, mounted on the upper table, made of a body and a cover, characterized in that it is equipped with a metal sleeve installed in the metal receiver with a gap, and a pressing piston placed with the possibility of movement in the cavity of the sleeve and made in the form of a hollow metal cup filled with a heat-insulating layer of the core mixture. 2. The device according to claim 1, characterized in that the gap between the sleeve and the metal receiver is filled with insulating material.