CNC machine tools are generally composed of the following parts:
● Host, which is the main body of CNC machine tool, including machine tool body, column, spindle, feed mechanism, and other mechanical parts. It is a mechanical part used to complete various cutting processes.
● CNC device is the core of CNC machine tool, including hardware (printed circuit board, CRT display, key box, paper tape reader, etc.) and corresponding software. It is used to input digital part program, complete input information storage, data transformation, interpolation operation and realize various control functions.
● The driving device is the driving part of the actuator of CNC machining services, including the spindle driving unit, feed unit, spindle motor, and feed motor. It realizes the spindle and feeds drive through an electrical or electro-hydraulic servo system under the control of a CNC device. When several feeds are linked, the processing of positioning, straight line, plane curve, and space curve can be completed.
● Auxiliary devices, some necessary supporting parts of the index control machine tool, to ensure the operation of the CNC machine tool, such as cooling, chip removal, lubrication, lighting, monitoring, etc. It includes hydraulic and pneumatic devices, chip removal devices, exchange worktables, CNC turntables, and CNC indexing heads, as well as cutting tools and monitoring and detection devices.
● Programming and other auxiliary equipment can be used to program and store parts outside the machine.
After the workpiece is clamped once on the machining center, the digital control system can control the machine tool to automatically select and replace the tool according to different processes, automatically change the spindle speed, feed rate of the machine tool, the motion track of the tool relative to the workpiece and other auxiliary functions, and complete the processing of multiple processes on several surfaces of the workpiece in turn. And there are a variety of tool changing or tool selection functions so that the production efficiency is greatly improved.
Due to the concentration of processes and automatic tool change, the machining center reduces the time of workpiece clamping, measurement, and machine tool adjustment, so that the cutting time of the machine tool reaches about 80% of the starting time of the machine tool (only 15-20% for ordinary machine tools); At the same time, it also reduces the time of workpiece turnover, handling, and storage between processes, shortens the production cycle, and has obvious economic effects. The machining center is suitable for small and medium-sized batch production with complex part shapes, high precision requirements, and frequent product replacement.
Comparison With CNC Machine Tools
The same with CNC milling is that the machining center is also composed of a computer numerical control system (CNC), servo system, mechanical body, hydraulic system, and other parts.
However, the machining center is not equal to the NC milling machine. The biggest difference between the machining center and the NC milling machine is that the machining center has the function of automatic tool exchange. By installing tools for different purposes in the tool library, the machining tools on the spindle can be changed through the automatic tool exchange device in one clamping to realize various machining functions such as drilling, boring, reaming, and tapping, grooving, and so on.
Classification by processing procedure
Machining centers can be divided into boring milling and turning-milling according to the classification of machining processes.
(1) Boring and milling
(2) turning and milling
Classification by number of control axes
The number of control axes, can be divided into:
(1) 3 axis machining
(2) 4 axis machining
(3) 5 axis machining – www.cnclathing.com/5-axis-machining
CNC Guide: Working Principle, Advantages, Comparison, More