A Study on the Hydraulic Copying System : 2nd Report, Turning of Noncircular Cross Section

Abstract

This paper deals with a special method of using the hydraulic copying system called polygon turning, namely turning of a noncircular cross section. Considering the relation between copying accuracy and the dynamic characteristics of the hydraulic copying system, the following results were obtained for estimation of error and improvement of the accuracy. (1) The error resulting from a simple polygon turning can be calculated from dynamic parameters, particularly from time constant, of the hyaraulic copying system and shape of model of a cross section for the turning. (2) The dynamic performance parameters of the copying system were suitably obtained from field measurement of frequency response using a plate cam as an input signal generator. (3) A method for modification of model shape to reduce the resultant output error was developed and applied to a polygon turning and a turning of helical shaft or screws. The validity of the method was confirmed by experiments.