SU1342586A1 - Method of producing castings by vacuum moulding - Google Patents

Abstract

The invention relates to foundry production, namely the manufacture of thin-walled, mainly artistic castings by vacuum molding. The aim of the invention is to simplify the process of manufacturing castings and increase productivity. The method includes operations: installing the flask on a model plate with a model, filling the flask with a refractory filler, sealing and evacuating it, removing the model and the side of the mold, followed by pouring with metal. The filling of the flask is carried out with a refractory filler with an average link diameter determined from the ratio obtained experimentally. Selection of the refractory filler fractions makes it possible to eliminate the use of a nonstick coating and to increase productivity by 20-25%. 2 tab. with

Description

1342

The invention relates to foundry, in particular to the manufacture of art castings by vacuum molding.

The purpose of the invention is to simplify the nological process of making castings and increase labor productivity by filling

flasks are made with refractory filler in 50 Hz frequency oscillations at

teleme with an average grain diameter, determined by emp-1 from the ratio

, Zb (1-ShK

 -

where G is the surface tension of the alloy, N / m;

P is the porosity of the refractory layer;

amplitude 0.75 mm for 20 s.

In tab. Figure 1 shows the effect of the average grain diameter of the refractory filler on the surface quality of the cast.

Example 2. Making iron casting. The mirror frame is produced in flasks 1000x1000x200 mm in the non-mechanized vacuum section.

R. N

filler;

vacuum in the mold.

Pa;

K - coefficient 4) the grain angularity index. 20 moldings, casting dimensions, mm: length

510, width 270, height 25, wall thickness 3-5. Casting material. The surface tension of the cast metal is 1.1 N / m, the density is 6950 kg / m. 25 Filling is performed at 1340 ° C. The vacuum in the form of 45 Kia. Sand is used to make molds.

- casting height, m; p is the density of the alloy, kg / m j g - acceleration of the force of the tin, m / s.

Taking into account the thermophysical and garnometric characteristics of the metal and the mold filler, as well as the geometrical size of the casting and the magnitude of the vacuum. without the use of a primary coating.

In the absence of a refractory filler with the required average grain diameter (equal to or less than the calculated grain, a change in the particle size distribution of the existing refractory filler is made by entering corrected fractions.

Example 1. An art cast is made. Base for an alumina wall lamp. Al-9, 315 mm long, 85 mm wide, 40 mm high, with a wall thickness of 3-8 mm. As a refractory additive; Sand brand T0315B is used with an average grain diameter equal to 0.315 mm. Dust-like quartz is used to correct the decrease in the average grain diameter. The temperature of the cast alloy is 710 ° C, the vacuum value in the form is 35 kPa; the PoKv-5 compaction of this alloy is carried out with vertical directional oscillations for 10 s at a frequency of 47 Hz and an amplitude of 1 mm.

In tab. 2 shows the surface quality of the castings produced.

From Tables 1 and 2 it follows that the use of refractory filler with an average grain diameter equal to or less than the calculated grain to produce molds provides artistic castings without a burner.

40

The application of the proposed method

will allow to exclude the use of non-stick coating in the manufacture of artistic castings and, at the expense of 4g of this, simplify the technological process and increase labor productivity by 20-25% as compared with the known technical solution.

50

55

Claims (2)

Invention Formula The method of making castings by vacuum molding, which includes installing the flask on a model plate with a model lined with film, filling the flask with refractory filler, sealing and evacuating it, removing the model and assembling the mold, followed by metal casting, distinguishes the superficial tension of the alloy of 0.834 N / m. The density of the cast alloy is 2200 kg / m. Castings are produced on a fully mechanized carousel line of vacuum forming in flasks 400x500x100 mm. The refractory filler is compacted with circular vertical amplitude 0.75 mm for 20 s. In tab. Figure 1 shows the effect of the average grain diameter of the refractory filler on the quality of the surface of the cast. Example 2. Production of iron casting. The mirror frame is produced in flasks of 1000x1000x200 mm in the non-mechanized vacuum section. 2Q01a5, which is compacted by vertical directional oscillations for 10 s at a frequency of 47 Hz and an amplitude of 1 mm. In tab. 2 shows the surface quality of the castings produced. From Tables 1 and 2 it follows that the use of a refractory filler with an average grain diameter equal to or less than a grain for producing molds provides artistic castings without a burn. The application of the proposed method will allow to exclude the use of non-stick coating in the manufacture of artistic castings and thereby simplify the process and increase productivity by 20-25% compared with the known technical solution. Invention Formula The method of making castings by vacuum molding, including the installation of flask on a model plate with a model lined with film, filling the flask with refractory filler, sealing it and evacuating, removing the model and assembling the mold, followed by pouring with metal, is different from 3142586 u and with the fact that, in order to simplify the technological process of making castings and increase labor productivity, the filling of the flask is produced with a refractory filler with an average grain diameter determined from d e )TO P (RY + N p where d is the average grain diameter of the refractory filler, m; 2K01A 0.404 1.11 0.116 0.114 Editor P. Geresi Compiled by V. Sazonov Tehred I.Popovich Proofreader A. Tsko 4549/8 Circulation 740 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d. 4/5 Production and printing company, Uzhgorod, st. Project, 4 G is the surface tension of the alloy, N / m; P - the porosity of the refractory nanolitel; K - coefficient of angularity of the filler grains; H - casting height, m; p is the alloy density, kg / m; g is the acceleration of the force of gravity, m / s2; Pg, - vacuum in the mold, Pa. Table 1 table 2 No Burn No Burn