SU1423261A1 - Method of producing shell moulds and cores - Google Patents

Abstract

- The invention relates to foundry. The purpose of the invention is to reduce the labor intensity, reduce the consumption of the binder and improve the quality of the shells. A pre-moistened mixture of granular material is fed and compacted into a cooled core box, cooling it and forming a frozen layer. When the specified thickness of the layer is reached, the core box is turned upside down by 180 ° C. and set on the stove. After removing the core box, the binder slurry is fed to the frozen mixture of granular material, forming a facing layer. As a result of the subsequent heating, the granular material is thawed and spontaneously removed through the hole in the slab. The resultant shell is removed and sent to form assembly. The invention will make it possible to reduce the labor intensity in the formation of the shell by a factor of 5 and to reduce the consumption of the basement by a factor of 2-3 with an increase in the strength of the shells. 3 il. i (L

Description

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Yu

with y

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The invention relates to foundry, in particular, to methods for producing shell molds and cores.

The aim of the invention is to reduce the labor intensity, reduce the consumption of the binder and improve the quality of the shells.

FIG. 1 shows a core box with a compacted mixture; in fig. 2 rod model; Fig, 3 - ready shell after heat treatment.

In the core box 1, cooled by the built-in elements 2, communicating with a cooler (not shown), the humidified mixture 3 of granular material is fed and compacted. Excess air during compaction of the mixture is removed through vents 4. After the granulated mixture is fed and compacted, it is cooled and a frozen facing layer is formed.

When the specified thickness of the frozen core layer 1 is reached, it is turned over 180 (pins 5 can be used) and placed on the slab 6. Then the core box 1 is removed ... and a bonding suspension is fed to the surface of the rod - model 7 from the frozen mixture 3 of this material. forming the layer 8. As a result of the subsequent heating of the rod model to 25–250 ° C, the granular material thaws and spontaneously is removed through the holes 9 in the slab 6. After heat treatment of the rod model, the facing layer 8 acquires high strength fouling shells obtained by the prototype. The resultant shell is removed and sent to form assembly.

Example. The mixing of granular material and water is carried out on the dry runners. Quartz sand of the mark K02 is used as a granular material with the following ratios of ingredients, wt%:

Sand K0295

Water5

The resulting mixture is fed to the bunker sandblasting machine. The core box 1 is prepared for operation, for which it is cooled to IQ With the inclusion of a refrigerator in communication with the cooling elements 2 embedded in the core box 1. Then, using a resurfacing machine, the core box 1 is fed and

sand-water mixture 3 is compacted and held in it for 3 minutes, after which the core box 1 with the mixture 3 is pribted 5 with pins 5 onto plate 6, the core box is removed, and the resulting rod model 7 is applied evenly with using a spray binder, a suspension having the following composition, wt%: Liquid glass 70 Water 20

Marshalit10

The slurry consumption is 10% by weight of the shell being formed. After applying the binder slurry, the rod model 7 is heated with gas-flame burners to obtain a shell with high strength, and the dried sand spontaneously flows out through the holes 9 in the slab 6.

Zircon, chromium magnesite, chromium iron, pin sand, metal shot, etc. can be used as zenith material.

Zb-like binders, both in finished form and with the addition of a dust-like fraction of the above-mentioned granular materials, are used as bbc dusts. The preparation of the mixture of granular material and water is carried out by mixing the ingredients using any mixer. The preparation of the binder slurry may be carried out using a paddle stirrer.

For laboratory tests of the proposed method, standard samples with a diameter of 50 mm and a height of 50 mm made from a mixture containing 0.5% silica sand K02 and 5% water are used as a model. Samples are compacted with n (: 1) using a laboratory copra and coolant they are placed in the refrigerator. Then a binder suspension is applied to the surface of the samples using an atomizer, having the following composition in wt.%:

Liquid glass80,0

Water; -10,0

Marshalite10.0

After D-2 min, the samples are subjected to heat treatment in a thermostat at 200 ° C for 10 minutes. Then, in the end part of the specimens, a hole with a diameter of 2 mm is calcined and sand is removed, obtaining a hollow shell with a thickness of 5 mm.

When using the proposed method, it is possible to use not only thermoplastic single, but also durable, for example metal,

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Claims (1)

The proposed method for the manufacture of shell molds and cores allows the following advantages to be obtained by reducing the labor intensity during shell formation by a factor of 5; a decrease in binder consumption by 2-3 times with an increase in the strength of shells Invention Formula A method of manufacturing casting shell molds and cores, comprising g ten 15 326; supplying the sand-water mixture to the rigging, its compaction, impregnation of the surface of the obtained form with the strengthening binder to the required depth, heat treatment of the form with subsequent removal of the unproven mixture, in order to reduce the labor intensity, reduce the consumption of the binder and improvement of the shells, prior to impregnation, the binder is used to freeze the surface of the mold, while the impregnation and heat treatment is carried out from the side of the working surface of the mold. (rig.1 eight (pijs.2