Device for the numerical control of the movement of a cutting tool with respect to a work piece, taking into consideration the diameter of said tool

摘要

1,019,897. Programmed control of machine tools. GENERAL ELECTRIC CO. Feb. 28, 1983 [March 7, 1962(2)], No. 8096/63. Heading G3N. An automatic compensation system compensates for the effect of the thickness of a cutting element on a work-piece, in a system as disclosed in Specification 1,019,896, by modifying the path of a cutting element carrier in dependence at a rate directly proportional to a pulse train proportional to the desired resultant carrier velocity or to an independent pulse train. As shown, the velocity command pulse train for circular interpolation from command 29, each pulse of which represents an angular increment of rotation of a torch carrier 605, is fed to a command phase counter 901 wherein a clock pulse from a divider 28, selected from a flip-flop in the second decade, modulates the counter output due to the velocity command pulse train. The modulate train is compared in a phase discriminator 18SP1/SP with the output of a resolver 905 driven by the torch carrier, suitably shaped by a shaper 911. A phase difference signal from the discriminator controls, through an amplifier 74SP1/SP, a servomotor 75SP1/SP coupled to the torch carrier. The resolver is fed from the divider 28 through a low-pass filter 62, a quadrature supply being derived via a phaseshift network. For an abrupt change in outward angle during linear interpolation the phase counter 901 is only fed from the divider with a clock pulse train, the angle T through which the torch carrier 605 rotates being determined by an angle T counter 919 set by the programme. An inside angle is cut by circular of a minimum radius determined by the diameter of the tool.