Control System Development in Experimental Numerical Control Lathe

Abstract: The numerical control engine bed is one kind is loaded with the procedure control system engine bed, this system can process uses the number or other symbolic code instruction stipulation procedure. In the definition refers the procedure control system, is the numerical control system or the numerical control installment.Although various numerical controls engine bed main function is different, structure numerous Jan Geyi, but, a set of quite perfect automatic numerical control engine bed should include following several basic essential factors: The mechanical main body part, the power section, the sensing examination part, the implementing agency part, the computer part, between various essential factors and the link relate mutually through the connection.The automatic numerical control technology is the manufacturing industry realization automation, the flexibility, the integrated production foundation; The automatic numerical control technology application is enhances the manufacturing industry the product quality and the labor productivity essential important method; The automatic numerical control engine bed is the defense industry modernization important strategic equipment, is relates the national strategy status and manifests the national comprehensive national strength level the important symbol.Our country has the independent copyright numerical control system, but the overwhelming majority numerical control engine bed also uses the overseas CNC system.Looked from the engine bed whole, regardless of the reliability, the precision, the production efficiency and the automaticity, are apart from the international advanced level also to have certain disparity.This design two major part begins from the lathe machine part shaping hardware electric circuit to test the automatic numerical control lathe control system to conduct the research, the design automatic numerical control lathe control circuit, satisfies the numerical control lathe the basic control function.The numerical control lathe control take realizes the lathe localization, the interpolation, the thread processing, the circulation processing, functions and so on multi-location tool rest automatic rotation as the foundation, to the mechanical system main constituent, carries on the computation shaping, and designs with it necessary hardware electric circuit, CPU uses at89C51 chip, because the internal procedure and the data-carrier storage capacity is unable to satisfy the request, therefore the expansion capacity is the 64K program memory 27512 and the 8K data-carrier storage 6264.The AT89C51 I/O mouth could not satisfy the input/output the request, the system expanded a programmable periphery parallel connection chip 8255, for satisfied to feed system positive and negative direction pulse counting, needed to have four counters, therefore the system expanded had three counter programmable fixed time/counters 8253, the keyboard and the display control used 8279 chips, the D/A transformation module uses the DAC0832, A/D transformation to use ADC0809, the photoelectricity isolation uses the TLP521 chip, step-by-stepped the motor-driven electric circuit to step-by-step the electrical machinery control chip by L297 and the power actuation electric circuit is composed.In the mechanical system structure shaping plan carried on the master drive system in detail, has rotated the tool rest, the cutting force, the trundle guide screw nut vice-, step-by-steps the electrical machinery computation shaping, and to the auto-feed system, the main axle pulse generator has carried on the design.The lathe bed selects Luoyang Engine bed Limited company the CJK0620 engine bed lathe bed part, including lathe bed, guide rail, headstock, cooling electrical machinery and so on major component; The tool rest selects the automatic rotation square tool rest unit; The main axle electrical machinery selects the multispeed exchange asynchronous motor, realizes the main axle speed change control; Crosswise, the longitudinal to feed selects the belt pulse encoder, may the independent control two tablecloth transmission machine carry on the actuation, may realize the interpolation operation, half closed-loop control.The control system is the numerical control lathe core, its design primary coverage including the X-Y work table design, the A/D switching circuit, the D/A switching circuit, the photoelectricity isolation electric circuit, the bipolarity H bridge merit puts the electric circuit, step-by-steps designs and so on motor-driven electric circuit and antijamming electric circuit, has provided the good hardware platform for the control system, unifies software software technologies and so on antijamming design, software trap design, watch-dog design, carries on half closed-loop control to the numerical control engine bed.When CPU sends out will step-by-step the electrical machinery control signal, inputs after the I/O parallel expansion mouth and the photoelectricity isolation electric circuit to step-by-steps the electrical machinery driver, the actuation step-by-steps the electrical machinery revolution, the rotary motion will transform by the trundle guide screw into the translation, will realize the work table X, the Y direction linkage.With step-by-steps the electrical machinery coaxial pulse generator feedback to step-by-step the electrical machinery revolution number, turns four groups signals after the photoelectricity isolation and four doubling circuits, namely X, Y direction forward and reverse, takes three group signal input exterior counter, another group signal direct input monolithic integrated circuit internal counter.Step-by-steps the electrical machinery to transfer one step every time the elongation, the corresponding counter can receive a pulse signal, the realization counting.In examines the non-spacing in the situation, after the monolithic integrated circuit sends out one to let step-by-step the pulse signal which the electrical machinery rotates, in the gap certain time read corresponding counter value, judges it whether loses step, the corresponding transmission goes down a step pulse signal or the compensation signal, simultaneously judges whether spacing, if discovers the spacing, stops the movement immediately, has like this then realized half closed-loop control.This topic passes through basically had achieved diligently the predetermined target, designs the numerical control lathe control system already the structure integrity, satisfied the numerical control lathe the basic function, might use this control system was the main source, applied the different technology, specially the new technology, developed the more numerical control engine bed control system…
Key words: Compound Follow-up Turning; Parallelogram Four-linkage; Structure Design; Finite Element Method; Optimum Design