CNC machine tool is the abbreviation of digital control machine tool. It is an automatic machine tool equipped with a program control system. The control system can deal logically with programs with control coding or other symbolic instructions and decode them so that the machine tools can move and process parts.
Features of CNC Machine Tools
The operation and monitoring of CNC machine tools are all done in this CNC unit, which is the brain of CNC machine tools. Compared with ordinary machine tools, CNC machine tools have the following characteristics:
High machining precision and stable machining quality;
It can carry out multi-coordinate linkage and can process parts with complex shapes;
When the machining parts change, it is generally only necessary to change the CNC program, which can save production preparation time;
The accuracy of the machine tool itself is high and the rigidity is large. It can choose favorable processing dosage and high productivity(usually 3 to 5 times that of ordinary machine tools);
The high degree of automation of machine tools can reduce labor intensity;
The quality of the operator is higher and the technical requirements for the maintenance staff are higher.
Classification and Application of CNC Machine Tool
Classification by Process Use
CNC machine rooms for metal cutting, including CNC lathes, CNC drilling machines, CNC milling machines, CNC boring machines, and machining centers. These machine tools are suitable for Yudan parts, small batches, and multi-variety and parts processing. Good size consistency, high productivity and automation, and high equipment flexibility.
Metal molding type CNC machine tool; This type of machine tool includes numerical control bending machine, numerical control combination punch machine, numerical control bending machine, numerical control turning pressure machine and so on.
CNC special machining machine tools; Such machine tools include CNC wire(electrode) cutting machine tools, CNC EDM machine tools, CNC flame cutting machines, CNC laser cutting machine tools, and special combination machine tools.
Other types of CNC equipment; Non-processing equipment uses CNC technology, such as automatic assembly machines, multi-coordinate measurement machines, automatic plotter and industrial robots.
Classification by mode of movement
Point control; The point control CNC machine tool is characterized by the fact that the moving parts of the machine tool can only achieve accurate movement from one position to another, and no processing process is performed during the movement and positioning process. Such as numerical control drilling machine, number by coordinates boring machine, numerical control welding machine and numerical control pipe bending machine.
Point line control; Point line control is characterized by the fact that the moving parts of the machine tool not only achieve the accurate movement and positioning of one coordinate position to another, but also achieve linear feed movement parallel to the coordinate axis or control the two coordinate axes to achieve oblique feed movement.
Profile control; The feature of the contour control CNC machine tool is that the moving parts of the machine tool can realize the linkage control of two axes at the same time. It not only requires the control of the starting and ending coordinates of the moving parts of the machine tool, but also requires the control of the speed and displacement of each point of the entire processing process, that is, requires the control of the motion trajectory, and the processing of the parts into straight lines, curves, or surfaces in the plane..
Classification by control mode
Open loop control; That is, the control method without the position feedback device.
Semi-closed loop control; Refers to the installation of an angular displacement detection device on the open loop control servo motor shaft. By detecting the corner of the servo motor, the displacement of the moving part is indirectly detected and fed back to the comparator of the CNC device. Compared with the input instruction, the difference is used to control the moving part.
Closed-loop control; It is a direct linear or rotary detection device at the corresponding position of the final moving part of the machine tool. The directly measured displacement or angular displacement is fed back to the comparator of the CNC device to compare with the input instruction displacement. Control the moving component with the difference. Make the moving parts move strictly according to the actual displacement required.
Performance classification of controlled machine tools by number
Economic CNC machine tools;
Midrange CNC machine tools;
High-grade CNC machine tools;
Fraction according to the composition of the CNC device used
Hard wire numerical control system;
Soft wire numerical control system;