The programmed processing program is transmitted to the numerical control device through the keyboard or input machine on the operation panel.
After the numerical control device performs a series of processing on the received signal, the processing result is distributed in the form of pulse signal: one is to send execution commands such as feed to the feed servo system, and the other is to send to the programmable controller S, M, T and other command signals.cnc machine manufacturer。
After the programmable controller receives S, M, T and other command signals, it controls the main body of the machine tool to execute these commands immediately, and feeds back the execution of the main body of the machine tool to the numerical control device in real time.
After receiving the feed execution command, the servo system will immediately drive each coordinate axis (feed mechanism) of the main body of the machine tool to accurately move in strict accordance with the command requirements, and automatically complete the processing of the workpiece.
During the displacement of each coordinate axis, the detection feedback device quickly feeds back the measured value of the displacement to the numerical control device for comparison with the command value, and then sends a compensation execution command to the servo system at a very fast speed until the measured value is equal to the actual measured value. Until the command value matches.
In the process of the displacement of each coordinate axis, if the phenomenon of "overtravel" occurs, the limit device can send some coordinate axis overtravel signals to the programmable controller or directly to the numerical control device. On the one hand, an alarm signal is issued through the display, and on the other hand, a stop execution command is issued to the feed servo system to implement over-travel protection.
In summary, the working principle of CNC machine tools can be summarized as follows: The computer in the CNC device performs a series of processing on the information recorded by the input device in the form of numbers and characters, and then sends the information to the computer through the servo system and programmable controller. The actuators such as the spindle and feed of the machine tool issue instructions, and the main body of the machine tool follows these instructions and cooperates with the detection feedback device to perform various actions required for processing the workpiece, such as the motion trajectory, displacement and advancement of the tool relative to the workpiece. Realize automatic control for speed and other requirements, so as to complete the processing of the workpiece.
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