Numerical control machine tool understands analyse formerly by control

Servo of open loop of machine tool of numerical control of 　 of 　 of servo of open loop of numerical control machine tool does not contain positional detecting element normally, servo drive component enters electromotor for the pace more, the data of the input allocates output directive pulse through the operation of numerical control system. Instruction pulse controls a pace to eat electromotor roll, repass main transfer machinery, make executive component mobile or rotational. Means of this kind of control is not to undertake detected instruction hair goes out to feedback no longer to the working circumstance of actuator come back, call open loop control.

Means of this kind of control is debugged convenient, maintenance is simple, cost is low, but pilot precision and speed are restricted, apply to the equipment of medium, small-sized numerical control with precision not high demand commonly. 2.

Detecting element installs the condition that servo of closed circuit of machine tool of numerical control of 　 of 　 of closed circuit servo controls means to must have detecting element to go up in workbench directly. When statement cost sends positional comparator, be like workbench to do not have shift right now, without feedback quantity, dictate the value makes servo electromotor rotational, drive workbench to move, right now detecting element workbench feedback of actual displacement quantity goes back, with the instruction in positional comparator the value undertakes comparative, undertake controlling with the poor value that after comparing, gets, till till differ,the value is eliminated, this is called closed-loop control. The advantage of means of control of machine tool of this kind of numerical control is precision tall, rate is rapid, but debug and maintain more complex, cost tall, use at athletic speed and precision requirement commonly equipment of higher big, medium-sized numerical control. 3.

Means of control of machine tool of this kind of numerical control is opposite 　 of 　 of servo of half closed circuit the real position of workbench does not undertake detecting, pass the corner that gives servo electromotor with indirect measurement of detecting element of servo electromotor contact however, push the actual displacement of cipher out workbench to measure then, undertake comparative with this value and statement cost, the value that use difference realizes control. Because workbench did not include completely to be inside control loop, drive the error of ball guide screw with mobile workbench to cannot be compensated, say consequently for servo of half closed circuit. Interpose of servo of half closed circuit is mixed at open loop between closed circuit, precision is taller than open loop, debugging is easier than closed circuit however, cost is inferior also, it is the system of a kind of numerical control that uses extensively. CNC Milling