Method of producing molds
AssigneeSintokogia Ltd.
InventorsNagato Uzaki, Ukichi Oishi, Ryoji Kanayama, Hironobu Amano, Tokiya Terabe
Life of this patent
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Abstract
Molding sand (5) is fed into a space defined by a pattern plate (2) and a flask (3) mounted on the pattern plate (2), and the space is enclosed at the upper part of the flask (3) by a cover (6). The air in the enclosed space is evacuated to reduce the air pressure between the grains of the molding sand in the enclosed space to 1 Torr to 150 Torr, and then air is introduced into the enclosed space from the upper part of the space so that the pressure in the space can increase at the rate of 15 atm/s to compress the molding sand (5). The method eliminates the need for vent holes and enables the mold to be crack-free since the air flow is not reflected.
Claims6
In a method of producing a mold that includes the steps of feeding molding sand into a space defined by a pattern plate and a flask mounted on the pattern plate;
- covering the upper part of the flask by a closing cover;
- and then pressing the molding sand by using an air flow, wherein the pressing step includes the steps of:
- evacuating air from the space enclosed by the pattern plate, the flask, and the closing cover, to make the space a vacuum so that the pressure of the air between the grains of the molding sand in the space is between 1 Tort and 150 Torr;
- and
- causing an air flow into the space from an upper part of the space such that the pressure in the space increases to the ambient pressure at a pressure gradient of at least 15 arm/s, thereby compressing the molding sand.
A method of producing a mold comprising the steps of:
- feeding molding sand into a space defined by a pattern plate and a flask mounted on the pattern plate;
- covering an upper part of the flask by a closing cover;
- evacuating air from a space enclosed by the pattern plate, the flask, and the closing cover, to create a vacuum so that the pressure in the space is between 1 and 150 Tort;
- pressing the molding sand by introducing an air flow into the space from an upper part of the space such that the pressure in the space increases from the vacuum to ambient pressure at a pressure gradient of at least 15 arm/s, thereby compressing the molding sand.
Dependencies are inferred from the claim text.