METHOD FOR PRODUCING PROFILED PRODUCT HAVING FINS

摘要

METHOD FOR PRODUCING PROFILED PRODUCT HAVING FINS The method of producing a profiled porduct having fins such as all impeller having vanes impossible to be formed directly by casting without collapsible cores comprises the steps of first producing by the casting a preliminary product having fins of the shape capable of directly formed by the casting, a concave filled out portion being provided at one side of the root of each fin varying its size or amount along the length of each fin depending upon the required final shape of the fin, while a corresponding cut out portion is formed at the opposite side of the root of each fin at the position corresponding to the above described concave filled out portion, and then applying a force to each fin so as to cause plastic deformation thereof at the position where the concave filled out and cut out portions are provided thereby permitting the. location of the root of each fin to be displaced toward the side provided with the filled out portion by the amount corresponding to the variation in the amount of the filled out and cut out portions to form the required final shape of each fin. Alternatively, concave filled out portions may be provided at both sides of the root of each fin which is positioned in inclined state with respect to the surface of the preliminary product with one concave filled out portion at the side forming an acute angle with the surface of the preliminary product being located inwardly therein with respect to the opposite concave filled out portion, and then a force is applied so as to cause plastic deformation of the fin for pushing up each fin into the upright position to thereby form the final shape of each fin having rounded concave surfaces at both sides of the root of each fin to thereby enhance the strength.