SU876263A1 - Moulds - Google Patents

Description

(54) CASTING FORM

 , The invention relates to foundry, in particular, to casting molds for producing castings, for example, permanent magnets, turbine blades, etc., having a columnar crystal structure and can be used in engineering and other industries related to casting. Multi-cavity casting molds made of a refractory material (sillimanite, chamotte) are known by pressing method 1. These molds require heating in special furnaces to a temperature of 1350-1700 C before being installed on the cooler and filled with metal. smelted models from high-alumina materials, which are heated by high-frequency current directly to the refrigerator and, after pouring, the output from the heating zone 2. The disadvantage of these forms is the manufacturing complexity and high oimost large power consumption for their heat, complicated and bottom koproizvoditelna -technologies producing castings with a columnar structure. Closest to the present invention is a mold containing a mold insert mounted on a refrigerator and external dry sand cores forming a gating system and profitable cavity 3; The disadvantage of this form design is the high consumption of expensive alloy for the gating system and the profitable part that heats the walls of the forming insert. The castings themselves account for 20-30% of the weight of the cast metal. The purpose of the invention is to increase. output is suitable. This goal is achieved by the fact that in a known casting mold containing a shaping insert mounted on a refrigerator and external dry sand cores forming a gating system and profitable cavity, the shaping insert is made with external stiffening ribs entering the internal grooves formed in the external cores , with the creation of closed air heat accumulative surfaces separated from the profitable cavity filled with metal by the walls of the forming insert and the wall of the internal groove of one from the outer rods, this gating system is framed in the outer rod, located under the bowl and made in the form of radial channels radiating from the center, passing into the profitable cavity.

FIG. 1 shows a diagram of a mold, a vertical section; in fig. 2 is a view A of FIG. one; in FIG. 3, section BB in FIG. one.

The casting mold consists of a gating bowl 1, an upper outer core - a lid 2, outer rods 3,4,5 with inner grooves b and 7, a refrigerator 8 and a shaping insert 9 with stiffening ribs 10. The inner grooves 6 and 7, the outer walls of the forming insert 9 and the ribs 10 stiffness create closed air heat-accumulating cavities. The outer core 3 forms a profitable cavity 11.

Casting tea, outer rods and forming insert are dry sand rods.

The metal being poured through the sprue cup and the flute channels fill the cavities of the forming insert. The crystallization starts from the cooler in the direction perpendicular to its surface, the heat of the liquid metal heats the air in the heat of the accumulating cavities, and creates a unidirectional columnar solidification in the absence of lateral growth; the actual ratio of the temperature gradient in the liquid metal and the crystallization rate must be higher than the critical one. Profit maintains these conditions for a time sufficient to form a bench zone over the entire height of the casting.

The application of the proposed form allows to obtain castings with a columnar structure formed throughout the volume for a length of 100-120 mm, i.e. exceeding the usual dimensions of such castings.

The economic effect of the introduction, taking into account the annual production of such magnets, will be only by saving charge materials 200-400 thousand rubles.

Claims (3)

1. Foundry production, 1961, 0 8 s. 6-9. 2. Questions of radio electronics. Ser. 1, Electronics, 1962, issue 8 s. 2 3. 3. USSR author's certificate 5 No. 324094, cl. B 22 C 9/02, 1967.