SU1426692A1 - Method of producing casting moulds for vacuum moulding and equipment for testing moulding materials - Google Patents

Abstract

The invention relates to a foundry industry, namely to vacuum molding, and can be used in the manufacture of sandstones and cast samples for the study of molding materials and the surface roughness of castings. The purpose of the invention is to obtain sand samples in the cavity of the mold, accelerate testing, use of various synthetic cladding films and expand technological capabilities. Models 5 are installed on substrates of facing synthetic film, previously placed on model plate 3, then models 5 and model plate 3 are coated with synthetic film, followed by filling the flask with molding material 36 to BepxHef o level of model 5 sand samples, applying film 35 , vacuuming the cavity of the flask 13, removing the films from the upper end surface of the model 5 sand samples, removing the models 5 samples, filling the cavities of the half-mold with the molding material 36 By means of compaction, autonomous vacuuming of sand samples by means of glasses connected to the vacuum system, the flasks 13 are filled with molding material 36 to the level of the control panel, films are applied and vacuum of the flasks 13 are vacuumized. In addition, the upper mold half is made with cavities of various heights equal to the diameter of sand samples and located above them, metal is poured into the cavity, 2 s. and 3 z. p. f-ly, 8 ill. 78 to (L

Description

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The invention relates to a foundry, namely, vacuum forming, and can be used in the manufacture of sand and cast samples for the study of molding materials and the surface roughness of castings.

The purpose of the invention is. obtaining sand samples in the cavity of the mold, acceleration of testing, the use of various facing synthetic films and the expansion of technological capabilities,

FIG. T shows the tooling for the implementation of the proposed method for the production of casting molds; figure 2fig. 3 - prepared using glasses; in fig. 4 is a view A of 20 FIG. 3; in fig. 3 - a glass with a double bottom; in fig. 6 - section bb in figure 3; in fig. 7 - form assembly; I in FIG. 8 is a section bb In FIG. A: The rigging (Fig. 1 and 2) - contains the form 75 | storage table 1 with socket 2 for; connection to an external vacuum system (not shown) and communication with the atmosphere, model plate 3 with a valve | with holes 5, models 5 for the preparation of sand samples .. Models 5 are installed on substrates (b-P) from a facing synthetic film (Fig. 6 and 4) and are lined with a synthetic film 12. In addition, the equipment contains a flask 13 , the sockets 14 and 15 for connection to the external vacuum system, the filter jacket 16 and the non-gas-permeable transverse The nozzle 17, the vacuum chamber 18 installed around the perimeter, and the lower vacuum chamber 19, the cups 20 communicating by means of hoses with the elements of the external vacuum system, including valves 21 and vacuum gauges 22 for autonomous regulation: 9 of the amount of vacuum in each sand sample, fortified from the outside of the flask 13 (Fig. 1-3). The cups 20 (FIG. 5) contain a double bottom 23, each of which forms a vacuum chamber 24, a nozzle 25, a filter casing 26, an outer surface of the wall 27 of the glass, is made with a bevel.

The fabricated bottom mold (FIG. 3) contains sand samples obtained using molding materials 28-33 (FIG. 6) required 30

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my grain, facing synthetic films 12, 34 and 35 (Fig. 2 and 4) cups 20, substrates 6-11 (Fig. 4) molding material 36, sealed with films 12, 35 and 37.

The assembly form (Figs. 7 and 8) consists of the lower half-form 38 and the upper half-form 39 installed on it with cavities 40-45, obtained by means of models equal to the diameter of the models of the sand sample and different in height.

The method is carried out as follows. at once.

Example 1. Preparing models of sand samples and substrates from a facing synthetic film. The material of models of the sand sample is wood. The models are made in the form of a cylinder with dimensions, mm: 0100, in an amount of 6 pieces. The molds are made in flasks with dimensions of 500500-200 / 200 m. The shaping surface is coated with a Savilen synthetic film with a thickness of 0.1 mm, and a plastic film with a thickness of 0.05 mm is used to seal the mold box. Substrates are made of synthetic film Sevilen of various thickness (0.10; 0.15 mm). The mold is cast with a C4-15 cast iron of the same heat. The vacuum in the form was maintained on the order of 65 kPa. The vacuum in the sand samples was 30, 40 and 50 kPa, respectively. Sand 1K016B was used as a molding material for the mold, and for filling the cavities of the half-mold and obtaining sand samples in them - sand of grain O, 1 mm.

On the model plate 3, substrates 6-11 are applied from a facing synthetic film with a pre-applied nonstick coating, after which models 5 of the sand sample are placed on the film 12 and 35 are removed and models 5 are removed from the cavities of the mold half. - the molding material 28-33 of the required grain size is removed (Figures 4 and 5), according to the conditions of the tests carried out, vibration compaction is carried out and glasses are placed for 20 seconds. double bottom, and the outer surface of the walls of the glasses 20 are made

with a bevel (Fig. 3), due to which the glasses are easily and with sufficient compaction to the side walls of the cavity of the half-form are inserted into the molding material 28-33 sand samples. After installing the cups 20, the molding mold 36 of the flask 13 to the level of the control room is further filled, the film 37 is applied and the flask is evacuated by connecting the upper vacuum chamber 19 to the external vacuum system through the fitting 15 and evacuating the molding material 28-33 in the cavities half molds by pumping air through the filter casing 26, the vacuum chamber 24, the nozzle 25 connected to the external vacuum system, while the molding table is disconnected from the external vacuum system. The process of making a sand sample and a half-mold as a whole is completed by vacuuming, and the regulation of the vacuum values in each sand sample is carried out autonomously by means of valves 21 and vacuum gauges 22 reinforced from the outside of the flask 13 and connected to the glasses by 20 hoses. Poluforma bottom ready. After that, the molds of the bottom are made from the model table 1 After making the mold, 38

the bottom is made the upper half-mold 39 according to the traditional technology, while the cavities for metal pouring are made of different heights (50, 70, 90, 110, 130 and M50) in order to measure the metalostatic pressure of the melt on the sand samples and equal to the diameter of 10 mm sandstones located above the samples them.

After making the bottom 38 and. the upper 39 half-molds are assembled into a mold and filled with melt (Fig. 7).

PRI mme R 2. The bottom half-form can also be made using one whole piece of synthetic film instead of several substrates made of a film of equal thickness and chemical composition. In this case, models 5 of the sand sample are mounted on the model plate 3 covered with a whole piece of film 34 (Fig. 2), after which holes are filled in it along the outer contour of the model of the sand sample and the models are coated with a film according to the proposed method. air exhaust from the pro

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The spaces enclosed between the film 34, laid under the models 5 of the sand sample and the film 12, which reveals the models 5 and the model plate 3, are made through the holes 4, filled in the model plate 3 and the film 34 laid on it. the sand sample is locally applied with a nonstick coating.

Further manufacturing operations for the manufacture of the mold and the production of castings are similar to example 1.

The use of the proposed method and equipment as compared with the prototype makes it possible to obtain sand samples in the mold cavity, speed up testing, reduce their labor intensity by 2-3 times, obtain stable results by studying synthetic films of different thickness under the same conditions and depth control. ) dilution in sand samples under constant molding conditions to melt melt.

In addition, when testing, it is possible to simultaneously examine the effect on the surface roughness of the metalostatic pressure casting by changing the height of the cavities in the top half-mold, the substrate thickness, the thickness of the nonstick coating, the size of the grain of sand, and the depth of depression in the sand sample using mathematical planning methods of experiments.

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Claims (5)

1. A method of making casting molds by vacuum molding, which includes installing the model on a model plate, facing the model with film, setting the mold box, filling the mold box with a molding material, sealing, applying the film onto the mold box, evacuating the mold box, removing the model from the half-form and assembling the mold and - so that, in order to obtain sand samples in the cavity of the mold, speed up the tests, use various synthetic cladding films and expand the natural possibilities, install sand models The sample is produced on a substrate of a facing synthetic film, previously placed on a model plate, then a face. The models and a model plate are filled with a synthetic film, the flasks are filled with molding material up to the top level of the sample sand patterns, and then the film is applied. the film is removed from the upper end surface of the sand sample models, the sample models are removed, the cavities of the half-mold are filled with a molding material, compacted, and an autonomous vacuuming of the sandy samples, further filling the flask with molding material to the level of the control room and evacuating the flask cavity. 2. A method according to claim 1, characterized in that, in order to create different metal-static pressure of the melt on the sand samples, the upper half-mold is filled with cavities of different height, above the diameter of the sand samples, 3. Equipment for testing molding materials containing a molding table with a vacuum cavity, a model with a model plate and a flask with a nozzle and a vacuum chamber, characterized in that, in order to obtain sand samples in the cavity of the mold, accelerate the tests, use various synthetic veneers films and, expanding technological capabilities, it is equipped with double bottom cups, each of which forms a vacuum chamber, which in the lower part is autonomously connected from the flask by a nozzle with an external vacuum the system, and the upper part of the double bottom is separated from the working cavity of the flask by a filter sheath, in addition, the outer surface of the wall of the glass is made with a bevel. 4. Equipment according to claim 3, characterized in that the external vacuum system is pressure-controlled independently for each nozzle of the vacuum chamber of the glass. 5. Equipment according to claim 3, about tl and - with the fact that the flask The perimeter of the vacuum chamber is equipped with a non-gas-permeable transverse partition, which forms the upper and lower vacuum lamers, each of which has connections for connecting with external vacuum system. 12 Fi.Z 21 12 Fi.Z View A fug. B - C 6 zs FIG. five 39