US 6,007,280 A · Production method of pattern for casting

Abstract

A method for improving dimensional accuracy of a casting pattern. A division block used to form the casting pattern is fixed on a block fixing surface of an NC machine and then the front surface is processed, leaving a stiffness holding portion at a bottom-most portion of the division block. The division block is then turned over and the rear surface is processed, removing the stiffness holding portion. The stiffness holding portion has sufficient thickness to secure stiffness of portions surrounding a through portion, enabling withstanding of a cutting force applied to the rear surface when the division block is turned over and the rear surface processed. Thus, a deviation in position of the tool during processing of the through hole on the rear surface from that of processing of the through hole on the front surface is suppressed.

Claims9

Dependent claims

A method of machining a pattern for casting having front and rear surfaces, both surfaces being subject to be machined to be a final pattern, said method comprising the steps of:

positioning the front surface of the pattern up and the rear surface down;
machining the front surface by a cutting tool to a maximum depth, said maximum depth being less than the distance between the front and rear surfaces to provide a redundant thickness portion adjacent said rear surface;
turning said pattern over after completion of machining of the front surface machining;
and
machining the rear surface of said pattern to profile the final pattern while at the same time entirely removing said redundant thickness portion.

2 more elements

Dependencies are inferred from the claim text.

Production method of pattern for casting

Life of this patent

Production method of pattern for casting

Life of this patent

Abstract

Claims9