Common faults of CNC machine tools and their classification
1 Introduction
Computer Numerical Control (CNC) machine tools are the main force of automated production. In modern precision machining, CNC machine tools are widely used for the purpose of improving production efficiency and product quality. For a non-professional, the operation of CNC machine tools is very complicated and prone to a variety of failures, which makes it necessary to solve technology problems in the use of CNC machine tools. , In order to timely and effective troubleshooting, accelerate the maintenance and repair process, reduce the production downtime to a minimum, so as not to bring the enterprise economic losses.
2 Classification of CNC Machine Tool Failures
From the aspect of influencing factors, CNC machine tool failures can be roughly divided into the following five categories.
2.1 Electrical Control System Failure
The failure of the electrical control system is mainly due to the aging and severance of wiring, circuit boards, electric appliances, etc., resulting in the development of faults such as failure to power, alarm flashes, and instability of machining accuracy.
2.2 Mechanical System Malfunction
The main components of the CNC machine tools mechanical system are its three major components: transmission system, guide rail system and spindle system, etc. These components are mainly mutual interference, lack of lubrication, wear and other mechanical wear. Malfunction of the mechanical system may cause interference of the transmission system, incorrect cutting distance and positioning accuracy, etc.
2.3 CNC System Failure
CNC system failure refers to the failure of the implementation of the program instruction by the servo system, which mainly reflects the communications between the program instruction and the electrical system, which affects the output of the drive motor and the command signal.
2.4 Software System Failure
The failure of the software system is mainly manifested in the wrong generation of cutting path of the machine tool, incorrect display of the post-processed information, failure of the language command, shutdown and crash of computer operation, etc.
2.5 Human Error
CNC machine tool failures due to human errors are mainly caused by improper programming, operation, maintenance and other links, resulting in the failure of the program, the machine suddenly shut down, etc.
3 Common CNC Machine Tool Malfunction
3.1 Malfunction of Axis Movement
The axis movement failure is mainly caused by the encoder of the servo motor, the interference of the mechanical system, and the failure of the transmission system and the motor.
3.2 Alarming Failure
The alarm failure refers to the failure of the programming error to cause the machine tool to stop running and emit an alarm signal.
3.3 System Command Failure
The system command failure refers to the failure to generate a command from the CNC control unit, resulting in a sudden stop of the machine tool.
3.4 System Start-up Failure
The system start-up failure refers to the failure to read and execute the program, which causes the machine tool to enter the normal state of operation.
3.5 Overload of Servo Motor
The servo motor is an important part of the CNC machine tool. Overload of the servo motor may cause failure of the machine tool to move, or slow down operation.
3.6 System Shutdown Failure
The system shutdown failure refers to the failure to stop the running machine tool in the normal or emergency state, and enter the shutdown state.
4 Conclusion
The common fault of CNC machine tools is a process of complex causes, and the fault is generally caused by a combination of various factors. Therefore, in actual maintenance and repair, we should not simply determine the cause of the fault, but take countermeasures in combination with the various factors, so as to avoid longer maintenance time and loss of production output.
