SU1097432A2 - Under-model plate for vacuum moulding - Google Patents

Abstract

PODMODELING VOLTAGE FOR VACUUM FORMING by auth. No. 680803, characterized in that, in order to improve the quality of the casting by increasing the gas permeability of the plate, a series of interconnected grooves are made on the working surface of the body, telling the coordinate holes of the body with the perforated portions of the replaceable sheet. (L with with N ft w ko

Description

The invention relates to foundry, in particular, to devices for shaping in the manufacture of castings by a vacuum-film method. A well-known sub-model plate for vacuum forming, comprising a housing with coordinate holes communicated with a vacuum system, and a replaceable sheet mounted on the working surface of the housing, ftj .

The disadvantage of this plate is that in the production of castings, models of which do not have recesses and grooves along the plane of contact of the model with the surface of the replaceable sheet after connecting the cavity of the plate to the vacuum, the film will loosely fit the working surface of the model. This is due to the fact that, due to the tight fit of the replaceable perforated sheet to the surface of the body of the model plate, the holes in the sheet that are not located under the coordinate holes in the body cannot communicate with the vacuum system. As a result, the air suction will be uneven and incomplete, and isolated cavities will be formed under the film, which leads to the appearance of defects that distort the geometrical and reduce the quality of the casting.

The aim of the invention is to improve the quality of the casting by increasing the gas permeability of the slab.

This goal is achieved by the fact that in a known plate on the working surface of the housing there is a number of interconnected grooves communicating the coordinate holes of the housing with perforated portions of the replaceable sheet.

FIG. t shows the submodel plate, cut; in fig. 2 - a submodel on a plate, a plan view. A sub-model plate (Fig. 1) contains a body t ,, I9 prepared from a metal of 10-30 mm thick with a grid of through coordinate holes 2 through which the fastening and fixing-elements 3 of model 4 pass. On

the working surface 5 of the housing 1 is made of a series of interconnected grooves 6, forming support ribs 7, and a replaceable perforated sheet 8 is installed, covering the specified row of grooves. The holes 9 of the perforated sheet 8 are located under the slots 6.

Molding using the proposed model plate is performed as follows.

The heated synthetic film 0 is lowered onto the model 4 and the perforated sheet 8 and connect the cavity 11 to the vacuum pump (not shown). Through the system of holes 9 in the perforated sheet 8 and model 4, grooves 6 on the working surface 5 and holes 2 in the housing t, air is drawn out from under the film 10, and the latter fits tightly to the surface of the model 4 and the replaceable sheet 8. When vacuuming the vacuum, the replaceable sheet 8 rests on the working surface 5 of the housing 1 and the ribs 7, which eliminates its deflection during the molding process. Then, a special flask 12 connected to a vacuum pump is installed on the sub-model plate. Sand is poured into a flask and, after pre-compaction with its vibration, the top of the flask is sealed with a synthetic film 13, and the cavity of the flask is communicated with a vacuum pump .; Under the action of the pressure difference outside and inside the flask, the molding sand is finally compacted. The cavity 11 oTKJH04aiOT from the vacuum pump and connected to the atmosphere, the finished mold half is removed from the submodel plate,

 Thus, in the proposed plate, a guaranteed connection of all the perforated sections of the replaceable sheet with the vacuum system is ensured, due to which its Permeability and, ultimately, the increase in the quality of the casting increases. The annual economic effect from the use of the proposed plate will be 12.0 thousand rubles. by improving the quality of castings,;

Claims (1)

GRINDING PLATE FOR VACUUM FORMING by ed. No. 680803, characterized in that, in order to improve the casting quality by increasing the gas permeability of the plate, a number of interconnected grooves are made on the working surface of the casing, communicating the coordinate holes of the casing with perforated sections of the replaceable sheet.