Patent ID: 6752196
Filing Date: 2004-06-22
Classification: B22C

Abstract:
A method for blowing and thereby introducing molding sand contained in a sand hopper into a mold space defined by a pattern plate having a pattern, a flask placed on the pattern plate for surrounding the pattern, a filling frame placed on the flask, and a plurality of vertically movable, multi-segmented squeeze feet that define a squeeze surface opposed to said pattern plate, said mold space being a substantially closed space having a substantially constant volume and said sand being blown from a plurality of separated nozzles at a lower portion of the sand hopper, which is located above the mold space, said method comprising the steps of:introducing a first airflow of compressed air at a pressure of 0.05 to 0.18 MPa into said sand hopper from an upper part of said sand hopper so as to blow and thereby introduce the molding sand into said mold space from said hopper through said separated nozzles; and aerating the molding sand in said sand hopper by supplying a second airflow of compressed air at a pressure of 0.05 to 0.18 MPa to the molding sand in said sand hopper to be introduced into the mold space from either or both of a lower inner portion and a lower peripheral portion of said sand hopper so as to fluidize the molding sand in said sand hopper, wherein a top surface of said pattern of said pattern plate has a convex and concave profile and the profile of the squeeze surface of said multi-segmented squeeze feet is in the form of a convex and concave profile that matches said convex and concave profile of said pattern.