PRODUCTION OF MOLD FOR CENTRIFUGAL CASTING OF FLANGED PIPE

摘要

PURPOSE:To cast simultaneously a pipe with two flanges with one casting mold by cutting away the intermediate part consisting of only the resin sand layer formed in a cylindrical metallic flask and forming an annular recess having the width corresponding to the thickness of two flanges. CONSTITUTION:A strickling bar 15 attached with a projection 14 having a prescribed shape is inserted into the metallic flask 3 under rotation at a low speed and the intermediate part consisting of the resin sand layers 10, 10' is cut away in the peripheral direction of the flask 3 except the layer having a suitable thickness by the projection 14. An annular recess 16 for forming a flange having the width corresponding to the thickness of the two flanges is formed. The cut away resin sand is discharged by high- pressure air to the outside of the flask 3. Sand stopping bands are then removed and in turn a pair of molten metal stopping bands formed with the resin sand layers on the opposed surfaces are pressed and fixed to a step part 6 and annular recesses 20 for forming flanges are formed to the end faces on both sides of the mixed sand layer 12'. The flask 3 provided with the resultant casting mold is rotated and the molten metal is poured therein, by which a cast iron pipe 23 having flanges 21, 23 at both ends and in the middle is cast.