Application Study On Theory Of Tracking Screw Thread Technology On Open NC System

From Logic Numerical Control to Computer Numerical Control, from the Radio tube NC, Transistor NC, the small and normal size Integrate Circuit (IC) NC to the small size Computer NC and Microprocessor NC, then to the Personal Computer NC nowadays, the Numerical Control teclinology of machine tools has come through six eras that is two phases. The every advancement of Numerical Control System was the symbol of the advancement in the mechanical manufactory industry.It has been the study and exploitation focus of the NC system exploitation and the machine tools manufacture that the Open NC system basing on PC and the movement controller. In the function, the Open NC system actualizes the graphics of user interface, the visualization of science calculation, the diversification of the interpolation and compensation mode, the integration of inside high-powered Programmable Logical Controller (PLC) and multimedia teclinology; on the framework, it achieves the closed-loop control mode which is integration, modularization, network and open.In this paper, according to the urgent need of the NC machining technology, which repairs the thread groove of the screwed workpieces, the theory of tracking screw thread technology is put forward. The difficulty of position-setting is resolved for the thread workpiece on the NC lathe in the theory. Though fixing the workpiece without position-setting in both axial direction and circumferential direction, adjudting the screwer by one thread groove accurately, and applying the finding position algorithm for the workpiece's end face and the tliread trace, then the workpiece position and the screw track are located exactly in the workpiece coordinate system. At the same time, control method of the tracking screw thread model is developed, applying the time-base trigger theory of the movement contioller and the feedback signal of the photoelectric encoder that is synchronizing with main axle absolutely, the offset between theactual starting point and the thread groove starting point is compensated. With the NC system of integrating the personal computer and the movement controller, the simple NC system of CAK6150 lathe is impioved to NC system of integrating the Open NC system and closed-loop control method. The theory of tracking screw tlvread technology is applied on the improved lathe. The trace disorder problem is resolved with this control method. Furthermore, the auto-program and dynamic emulation software is designed, in this software, the key parameters are inputed, the NC program will created out immediately, and the dynamic emulation will be accomplished, for checking up the validity of the NC program.This paper's production will make the functions of NC lathe stronger, will enhance NC lathe to applying extensively in drill pipe repairing in oil field, and will promote the development of the petrol industry.