CNC machine tools generally consist of input and output devices, CNC devices, programmable logic controllers, servo systems , detection and feedback devices, and the machine tool host.
1. Input/Output Devices: Input devices transmit various machining information to the computer. In the early days of CNC machine tools, punched paper tape was used as an input device, but this is now largely obsolete. Currently, keyboards, disks, etc., greatly facilitate information input. Output refers to the output of internal operating parameters (including original parameters under normal and ideal working conditions, fault diagnosis parameters, etc.). Generally, these parameters need to be output and recorded when the machine tool is first started working. After working for a period of time, the output is compared with the original data to help determine whether the machine tool is maintaining normal operation.
2. CNC Device: The CNC device is the core and driving force of a CNC machine tool. It processes and calculates all machining data, ultimately controlling the various functions of the CNC machine tool. It includes microcomputer circuitry, various interface circuits, a CRT monitor, and other hardware and corresponding software.
3. Programmable Logic Controller (PLC) controls the spindle unit, processes the speed commands in the program to control the spindle speed; manages the tool magazine, including automatic tool exchange, tool selection mode, cumulative tool usage count, remaining tool life, and tool sharpening count; controls spindle forward and reverse rotation, stop, near stop, coolant switch, chuck clamping and loosening, and robot tool loading and unloading; controls external machine tool switches (limit switches, pressure switches, temperature control switches, etc.); and controls output signals (tool magazine, robot, rotary table, etc.).
4. The detection feedback device consists of detection elements and corresponding circuits. It mainly detects speed and displacement and feeds the information back to the CNC device to achieve closed-loop control and ensure the machining accuracy of the CNC machine tool.
5. Machine tool host: The main body of a CNC machine tool, including mechanical components such as the bed, spindle, and feed transmission mechanism.
