Working principle of CNC machine tools

September 11, 2024

CNC machine tools, full name Computer Numerical Control Machine Tools, are advanced equipment that use computer programs to control the movement and processing of machine tools. It accurately controls the motion trajectory, speed and cutting parameters of each coordinate axis of the machine tool through pre-programmed programs, thereby achieving high-precision processing of various complex parts.

CNC machine tools are mainly composed of CNC systems, servo systems, machine tool bodies and auxiliary devices.

CNC system: equivalent to the "brain" of CNC machine tools, it receives instructions from programmers and converts these instructions into signals to control the movement of machine tools. CNC systems usually consist of hardware and software. The hardware includes computers, controllers, etc., and the software includes programming software, control software, etc.

Servo system: It is the "actuator" of CNC machine tools. It controls the precise movement of each coordinate axis of the machine tool according to the instructions issued by the CNC system. The servo system is mainly composed of servo motors, drivers and position detection devices.

Machine tool body: It is the "body" of the CNC machine tool. It includes components such as the bed, column, workbench, spindle box, etc., which are used to support and install other components and realize the processing of workpieces.

Auxiliary devices: including tool library, automatic tool changer, cooling system, chip removal system, etc., which are used to improve the processing efficiency and automation of CNC machine tools.

Working principle of CNC machine tools

1. Programming and input

First, programmers use programming software to write CNC machining programs according to the processing requirements of the workpiece. Programming software usually provides an intuitive graphical interface and rich programming instructions, so that programmers can easily describe the shape, size and processing technology of the workpiece.

The completed CNC machining program is input into the CNC system through the communication interface or storage medium.

2. CNC system processing

After receiving the machining program, the CNC system parses and processes the program. It converts the instructions in the program into pulse signals that control the movement of each coordinate axis of the machine tool, and calculates the movement speed, acceleration and displacement of each coordinate axis according to the processing requirements.

3. Servo system execution

After receiving the pulse signal from the CNC system, the servo system drives the servo motor to rotate. The servo motor drives the worktable, spindle and other components of the machine tool to move precisely through transmission devices such as couplings and lead screws.

The position detection device detects the actual position of each coordinate axis of the machine tool in real time and feeds back the detection results to the CNC system. The CNC system adjusts and controls the servo system based on the feedback information to ensure the movement accuracy of the machine tool.

4. Processing process

During the processing, the tool cuts the workpiece according to the instructions of the CNC system. The cutting parameters of the tool, such as cutting speed, feed rate and cutting depth, are set by the programmer in the processing program.

As the various coordinate axes of the machine tool move, the tool gradually cuts the required shape and size on the workpiece. During the processing, the cooling system and chip removal system will cool and remove chips for the tool and workpiece in time to ensure the smooth progress of the processing.

5. Processing end

When the workpiece is processed, the CNC system will issue a stop command, and the servo system will stop driving the movement of each coordinate axis of the machine tool. The operator can take out the processed workpiece and carry out the next step of inspection and processing.

Through the coordinated work of the CNC system, servo system and machine tool body, CNC machine tools can achieve high-precision and high-efficiency processing of workpieces. With the continuous advancement of science and technology, the performance and functions of CNC machine tools will continue to improve, providing stronger support for the development of modern manufacturing.

Author:

Ms. CTT TECHNOLOGY (UK) LIMITED

E-mail:

haiqi.liang@chuntian-ctt.com

Phone/WhatsApp:

+86 13318966480