ation and in a timely manner increased level of automation in production equipment and efficiency, improve the quality of equipment and grades, and the old machine will be replaced by the current level of machine.
可根据技术革新的发展速度，及时地提高生产设备的自动化水平和效率，提高设备质量和档次，将旧机床改成当今水平的机床。
五 the choice of NC System
五、数控系统的选择
NC system are the three major types of transformation, in accordance with specific circumstances Choose.
数控系统主要有三种类型，改造时，应根据具体情况进行选择。
5.1, stepper motor drive the open-loop system
5.1、步进电机拖动的开环系统
The servo drive system is stepper motor, stepper motor power, such as electro-hydraulic pulse motor. NC system by sending commands to the progress of pulse, the drive control and power amplifier circuit, the stepper motor rotate through the gears with ball screw drive of the implementation of parts. As long as control commands the number of pulses, frequency and electricity sequence can control the implementation of parts of the displacement movement, speed and direction of movement. Such a system does not require the test will be the actual position and velocity feedback to the input, so called open-loop system, the system accuracy of the displacement in the major decisions of the stepper motor angular displacement accuracy, transmission gear and other components of the leads crew pitch accuracy, the accuracy of the lower displacement.
该系统的伺服驱动装置主要是步进电机、功率步进电机、电液脉冲马达等。由数控系统送出的进给指令脉冲，经驱动电路控制和功率放大后，使步进电机转动，通过齿轮副与滚珠丝杠副驱动执行部件。只要控制指令脉冲的数量、频率以及通电顺序，便可控制执行部件运动的位移量、速度和运动方向。这种系统不需要将所测得的实际位置和速度反馈到输入端，故称之为开环系统，该系统的位移精度主要决定于步进电机的角位移精度，齿轮丝杠等传动元件的节距精度，所以系统的位移精度较低。
The system is simple, convenient debugging maintenance, reliable, low cost, easy modification success.
该系统结构简单，调试维修方便，工作可靠，成本低，易改装成功。
5.2, or asynchronous motor DC Motor Drive, grating feedback loop measurement NC system
5.2、异步电动机或直流电机拖动，光栅测量反馈的闭环数控系统
And the open-loop system is the difference between a system: from the grating, such as position sensors for simultaneous detection device measured the actual position feedback signals, at any time and to compare the value will be the difference between the two enlarge and ch
