US 4,902,951 A · Numerically controlled machine tool

Abstract

A numerically controlled machine tool for machining a non-circular workpiece according to profile data. The numerical controller stores phase compensation values and position compensation data files in connection with the types of cam and the various rotational speeds of the main spindle. Each position compensation data file consists of a series of position compensation values for a successive rotational positions of the main spindle. The numerical controller searches a phase compensation value and a position compensation data file according to the type of cam to be ground and the rotational speed of the main spindle during the grinding operation. Thereafter, the numerical controller offsets the read-out position of the profile data by the amount corresponding to the searched phase compensation value, and compensates each profile data with position compensation data stored in the searched file so as to eliminate a machining error which changes depending upon the rotational speed of the main spindle.

Claims5

Dependent claims

A numerically controlled machine tool for machining a non-circular workpiece by controlling numerically the main spindle rotation and the position of the tool according to profile data which defines the profile generating movement of a tool along a final shape of said workpiece, said numerically controlled machine tool comprising:

profile data memory means for storing profile data which is calculated form an ideal sectional shape of said workpiece and indicates positional change of said tool with respect to the rotational position of said workpiece;
numerical control data memory means for storing numerical control data which commands to perform at least two successive machining steps in which the position of said tool is controlled in accordance with said profile data, and commands the rotational speed of said main spindle to be changed at each machining step;
compensation data memory means for storing at least two groups of compensation data which are used for compensating for follow delay of the tool feed, in connection with the rotational speeds of said main spindle at said at least two machining steps;
and
control means operable in response to said numerical control data for searching one group of said compensation data corresponding to the commanded rotational speed of said main spindle during said each machining step from said compensation data memory means, and for compensating said profile data with said searched group of compensation data so as to control the position of said tool while eliminating said follow delay.

2 more elements

Dependencies are inferred from the claim text.

Numerically controlled machine tool

Life of this patent

Numerically controlled machine tool

Life of this patent

Abstract

Claims5