Parts of CNC Machine and Their Functions
When machines are used to operate a Numerical Control (NC) machine tool, the device is called a CNC machine. In other words, the use of machines to monitor machine tools such as lathes, mills, slotters, shapers, etc. is termed a CNC machine.
Main Parts of CNC Machine
1. Input Devices:
These are instruments that are used to input the component software to the CNC computer. There are three widely used input machines, such as a punch tape reader, a magnetic tape reader, and a monitor with RS-232-C connectivity.
2. Computer Control Unit (MCU):
It is the foundation of the CNC machine. It handles all the monitoring acts of the CNC machine, the different tasks done by the MCU.
- It reads the encoded instructions that have been inserted into it.
- The coded instruction is decoded.
- Interpolation is used to produce axis motion commands.
- It supplies the axis motion commands to the circuits of the amplifier to drive the axis mechanisms.
- It provides the location and frequency feedback signals for each drive axis.
- It incorporates auxiliary control functions like coolant or on/off spindle and tool shift.
3. Machine Tool:
A CNC machine tool is often fitted with a sliding table and a spindle to regulate position and speed. The computer table is operated in the direction of the X and Y axes, and the spindle is used in the order of the Z-axis.
4. Driving System:
The operating mechanism of the CNC unit consists of the circuit amplifiers, the drive motors, and the main ball screw. The MCU supplies the signals (i.e., place and speed) of each axis to the circuits of the amplifier. The control signals are then raised (enhanced) to actuate the drive motors. And the actuated drive motors turn the central ball screw to position the system table.
5. Feedback System:
The system consists of transducers that function as sensors. It's sometimes called a weighing device. It includes location and speed transducers that continuously track the position and speed of the cutting tool positioned at any time. The MCU collects signals from these transducers and uses the discrepancy between the reference signals and the input signals to produce control signals to resolve location and speed mistakes.