SU904873A1 - Casting mould - Google Patents

Description

I

The invention relates to foundry and can be used in the manufacture of castings, for example, by a vacuum process.

The design of vypors or ventilation ducts on a mold with a vertical connector is not difficult, in contrast to the forms with a horizontal connector.

A known tooling for the manufacture of sand molds by the method of vacuum forming, in which there are no vyporov or ducts, ensuring the preservation of the configuration of the casting tool in the process of forming and pouring the joint venture.

In a mold made with this tooling, due to the pressure fluctuations on the molds, the preservation of the configuration is not ensured, which is a significant drawback of the tooling.

Also known tooling for pouring into molds from dry molding

materials using vacuum, implementing the method of vacuum forming 21.

The rig has the following features. The uppermost part of the mold cavity is connected by a special air duct (equivalent to a vypor) with the atmosphere, for which a hole is made opposite the air duct in the sealing element. Litnikova

10, the system is performed by installing a burnable model. The body of the mold under vacuum may prematurely communicate with the cavity of the mold, where the sealing element is already melting, and the metal has not yet occupied its place, with the result that the air from the cavity of the mold can be sucked under the action of a vacuum through the body of the mold into a vacuum system down

Claims (2)

20 the difference between dgheny between the body and the cavity of the form, which leads to its destruction. After the mold cavity is filled with metal, the latter can freely fill the air duct and pour it onto the surface of the mold. This leads to unjustified waste of metal. A casting tooling is also known, in which a channel for communicating the mold cavity with the atmosphere is made through a connector} between the upper and lower half-form, for which the upper half-form is made with a depression, and the lower one with a protrusion, forming between them a gap communicated with channel 31. This device greatly simplifies the fabrication of the vapor tube (duct) and increases the reliability of its operation. However, here too, an inevitable waste of liquid metal due to the leakage of the latter into the duct and through the connector of the mold. Closest to the present invention is a mold, which includes the upper and lower half-molds, the working cavity, the upper part of which is connected to the atmosphere through an abutment, a profitable cavity with a channel, an overlapped gate, and a gating system 1. However, such a mold has large metal losses and low quality of castings. The purpose of the invention is to reduce metal losses and improve the quality of the metal. The goal is achieved by the fact that, in a mold that includes the bottom and the bottom half of the mold, the working cavity, the upper part of which is connected to the atmosphere through a strut, the lumen with a channel is blocked by and the gating system, the shutter is made in the form of a ball valve of an exothermic mixture with a guide. The drawing schematically shows the proposed mold, the general form. The mold includes half molds of the bottom 1 and top 2, connected vacuum wires 3 and a vacuum source. Inside each flask, a filter casing of 5 sec. corners 6. Cavity 7 of the casting mold is formed of dry molding material enclosed between thermoplastic films 8-11. Release 12 is performed at the top of the working cavity of the mold. Inside the bobber, a wire hook 13 is passed (in diameter A much smaller section of the bobber) with a curved upper end that prevents the mold from lowering into the cavity. At the lower end of the wire hook, a bolt is fixed — a ball of an exothermic mixture with a specific weight of not more than 3 g / cm. The tooling is equipped with a gating system 15 with a funnel 16. The work of the tooling is carried out as follows. A heated synthetic film 9 is applied to the lower half of the model, which presses the configuration of the model. Then the bottom flask is installed, filled with molding material, the synthetic film 8 is applied on top, The flask is connected using a vacuum line 3 to the vacuum and compacted by suction of air through the wall of the flask with holes 6. Then it is removed from the bottom half , cant and installed on the assembly. Similarly, the upper half of the mold is made using a mold box, a molding material enclosed between synthetic films 10 and 11, which is secured when connected to a vacuum source using a vacuum wire A. Before assembling the half-shapes S, the opening of the piping 12 is passed through fixed on the lower end of the ball of exothermic mixture, while the upper end of the wire is bent, preventing the wire from falling into the cavity of the form. When pouring a liquid metal into the funnel 1b, the metal in the gating system 15 fills the mold cavity. At this time, the air in the mold cavity freely flows through the flange 12 and the gap 17 between the ball and the roof of the profitable part of the casting. As soon as the liquid metal reaches the level of the ball, the latter begins to rise on the surface of the metal due to the difference in the specific weight of the metal (6.8 g / cm 1 and the material ball: ka (exothermic bond with a specific weight of not more than 3 g / cm), and at this time, the wire completely acts as a guide. In the highest position, the ball completely covers the holes of the vipor, preventing excessive consumption of liquid metal. At this time, the exothermic mixture heats the profitable part of the casting, helping to eliminate shrinkage defects, which is especially important. Casting shaped castings from steel. The invention eliminates liquid metal overflow (thereby increasing the yield) and improves the quality of cast billets by reducing shrinkage defects in the product. The economic effect of using the invention is achieved by saving liquid metal. , which includes the upper and lower half-molds, the working cavity, the upper color of which is connected to the atmosphere through a flange, the profitable cavity with the channel closed by the shutter and the sprue system distinguish This is so that, in order to reduce metal losses and improve the quality of castings, the valve is made in the form of a ball valve from an exothermic mixture with a guide. Sources of information received 80 Eaimanie during the examination 1. Technologies and equipment for foundry. Express information, 1979, No. 5, p. . 2. US patent ff 3825058, cl. 8 22 D 27/16. publish . The author's certificate CCC 599909, cl. C 22 C 9/00, 1978.. USSR author's certificate ff 58805, cl. B 22 C-9/08, 1975.