RU135554U1 - DEVICE FOR MANUFACTURE OF POROUS CASTINGS OF VACUUM IMPREGNATION - Google Patents

Abstract

A device for the manufacture of porous castings by vacuum impregnation, comprising a body with a gas outlet and a backing made of polystyrene granules clad with a reinforcing shell, mounted on a stand, a cover, an extension with a gate funnel mounted on the cover, and a bottom insert with a fitting, an opening in which is for connection with a vacuum system is blocked by an insert with ventilation grooves, characterized in that the housing is perforated to remove gaseous products of thermal decomposition of polystyrene foam, while house housing bore installed inserting a rod with a semicircular head, and with a sliding fit snugly against the outer surface of the head body.

Description

The utility model relates to foundry and metallurgical production, in particular, to the production of porous cast billets (castings, ingots) from metals with a low melting point and low-melting metals and their alloys used for the manufacture of parts in mechanical engineering and other industries.

Known chill mold for the manufacture of porous castings from aluminum and its alloys by vacuum impregnation of water-soluble fillers, containing a housing, a bottom, a filler and a vacuum wire (Porous cast aluminum // Foundry, 1997. - No. 8-9; p. 56-57, Fig. 1. Obtaining by impregnation of porous castings from aluminum alloys // Foundry, 2010. - No. 5; pp. 14-15, Fig. 5).

The disadvantages of this chill mold when using it to obtain porous castings are structural and technological flaws: the inability to apply a blow to the bottom of the chill mold when knocking the casting out when it is welded to the body, since the bottom is closed by the wall of the vacuum wire; the use of a soluble filler requires an additional operation — soaking the manufactured castings in water so that pores form in them; heating the filler before pouring the melt, requiring additional energy consumption, which complicates the process of obtaining porous castings.

Closest to the proposed technical essence is a device for the manufacture of porous castings by vacuum impregnation, comprising a housing, a liner-bottom and a pore-forming filler, in which the housing is mounted on a stand and equipped with a removable cover with a hole for the extension with a gate funnel, and the liner-bottom is equipped with a fitting , the opening of which for connection with a vacuum system is blocked by an insert with grooves-vents, while the pore-forming filler located in the housing is made in the form of filling granules of foam styrene clad with a reinforcing shell, and in the upper part of the casing a hole is made for the outlet of gases generated during thermal decomposition of polystyrene foam (Utility Model Patent No. 128136 of the Russian Federation, IPC B22D 25/00; publ. 05.20.13; Bull No. 14).

The main disadvantage of this device is that in the upper part of the device case there is only one gas outlet (channel) for the release of gases, which is insufficient for timely removal of gaseous (combustible) products of thermal decomposition of polystyrene foam and lead to their accumulation, popping and emission of liquid metal through the gate funnel, to the violation of safe working conditions.

The technical result of the device for the manufacture of porous castings is the creation of a device for the manufacture of porous castings by vacuum impregnation of metals with a low melting point and low-melting metals and alloys using expanded polystyrene granules with a reinforcing shell with a vent system for removing gaseous products of thermal decomposition as a pore-forming filler, to prevent claps and emissions of molten metal, ensuring efficient, reliable operation and no dangerous working conditions during operation.

The technical result is achieved in that in a device for the manufacture of porous castings by vacuum impregnation, comprising a body with a gas outlet and backfill of polystyrene granules clad with a reinforcing shell, mounted on a support, equipped with a cover with an opening for an extension with a gate funnel and a bottom insert with a fitting, an opening which for connection with a vacuum system is blocked by an insert with ventilation grooves, to remove the gaseous products of thermal decomposition of polystyrene foam, the casing is made forirovannym, wherein each hole is provided with an insert formed as a rod with a round head, and with a sliding fit snugly against the outer surface of the head body.

The essence of the utility model is illustrated by drawings, where in FIG. 1 shows a device for producing porous castings with a perforated body assembly (in section); in FIG. 2 hole for the exit of gases with an insert in the form of a rod with a semicircular head (pull-out "A", increased); in FIG. 3 - openings for the exit of gases with inserts in the upper part of the housing (section I-I); in FIG. 4 openings for the exit of gases with inserts in the middle of the body (section II-II); in FIG. 5 openings for the exit of gases with inserts in the lower part of the housing (section III-III).

A device for the manufacture of porous castings contains a perforated housing 1 mounted on a support 2. On top of the housing 1 has a removable cover 3 with an opening on which the extension 4 is located, made integrally with the gate funnel. In the lower part of the body there is an insert-bottom 5 with a nozzle 6. The hole in the nozzle 6 for connection with a vacuum system is blocked by a fake insert 7 with grooves-vents 8. A filling 9 of polystyrene foam granules with a reinforcing shell is placed in the cavity of the body 1.

During thermal exposure to polystyrene foam granules, thermal decomposition (softening, formation of volatile substances, intense gas evolution and burning) of polystyrene foam occurs.

To remove gaseous products of thermal decomposition of polystyrene foam, the housing 1 is perforated (Fig. 1), and the holes 10 (for example, four holes in five levels of the housing) are equipped with inserts 11 in the form of rods with semicircular heads (Fig. 2) installed with a sliding fit and tight fit of the heads to the outer surface of the housing (Fig. 3, Fig. 4 and Fig. 5).

The number of holes 10 in the perforated housing 1 (in the longitudinal and transverse directions) and the distance between them are selected depending on the size of the obtained porous preform, on the volume of filling of polystyrene foam granules with reinforcing shells, on the volume of gaseous products formed during thermal degradation.

The operation of the device for the manufacture of porous castings by vacuum impregnation is as follows. First, an assembly is made, for which purpose a liner-bottom 5 with a fitting 6 is installed in the housing 1 and placed on a stand. A hose 12 is put on the nozzle 6, after which the hole in the nozzle 6 is closed with an outflow insert 7 with vents 8 and backfill 9 of polystyrene foam granules with reinforcing shells. The housing 1 is covered with a removable cover 3 with an opening, on which an extension (extension) 4 with a gate funnel is placed, and the joints are sealed. The device is ready for pouring metal (for example, aluminum or silumin) melt.

Before filling, a vacuum system is turned on, a vacuum (vacuum) is created in the housing 1 and filling is performed. The melt under the influence of atmospheric pressure difference and vacuum in the casing (pressure in the vacuum receiver) enters the casing 1 and fills the gaps (discontinuities) in the filling of 9 polystyrene granules with a reinforcing shell over the entire height of the formed porous casting.

In the process of filling the body and solidification of the melt, as the filling of the granules to higher temperatures, thermal degradation occurs (softening, melting, gasification) of polystyrene foam. In the cavity of the housing 1, gaseous products are formed and accumulate, the pressure rises. In those places where the pressure exceeds atmospheric, openings 10 open, while the inserts 11 in the form of rods with semicircular heads are fully extruded (squeezed out) from the holes and the gases freely exit (under the exhaust probe). Filling the mold with the melt and hardening the billet (casting) takes place calmly, without claps and metal emissions, which ensures safe working conditions. Prior to decomposition of expanded polystyrene under conditions of rarefaction (vacuum), the insert heads are tightly pressed to the outer surface.

After cooling, the porous casting is removed (knocked out of the casing), for which the following operations are performed: the profitable extension is removed and the molding mixture forming the gate funnel is knocked out of it, the sprues are removed (separated) from the casting and the porous casting is shaken out by tipping the casing.

The proposed device for the manufacture of porous castings from metals with a low melting point and low-melting metals and their alloys by vacuum impregnation with a perforated body and inserts for removing gaseous products of thermal decomposition of polystyrene foam prevents cotton and metal emissions, provides effective, reliable operation and safe working conditions during operation allows you to get high-quality porous castings.

Claims (1)

A device for the manufacture of porous castings by vacuum impregnation, comprising a body with a gas outlet and a backing made of polystyrene granules clad with a reinforcing shell, mounted on a stand, a cover, an extension with a gate funnel mounted on the cover, and a bottom insert with a fitting, an opening in which is for connection with a vacuum system is blocked by an insert with ventilation grooves, characterized in that the housing is perforated to remove gaseous products of thermal decomposition of polystyrene foam, while house housing bore installed inserting a rod with a semicircular head, and with a sliding fit snugly against the outer surface of the head body.

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