The automatic feed function of the CNC machining center means that the machine tool can automatically control the tool feed process to achieve efficient cutting operations. This feature brings a variety of benefits, including increased productivity, reduced operator burden, and reduced tool wear. The following are some characteristics and working principles of automatic feed of CNC machining centers:

1. Program control: Automatic tool feed is realized through the program in the CNC system. In the machining program, parameters such as the tool's feed depth and feed speed can be specified, and the CNC system is responsible for automatically controlling the entire feed process.

2. Sensors and feedback systems: CNC machining centers are usually equipped with various sensors to monitor information such as tool position and workpiece status. These sensors provide real-time feedback, allowing the system to adjust the cutting process according to actual conditions.

3. Tool length compensation: In order to ensure the accuracy of cutting depth, CNC systems usually support tool length compensation function. During the automatic feed process, the system can adjust according to the actual length of the tool to ensure precise control of the cutting depth.

4. Tool detection and wear compensation: Some advanced CNC machining centers are also equipped with tool detection systems that can detect tool wear. The system can adjust the tool feed depth in real time based on the detection results, extending tool life and maintaining processing quality.

5. Safety protection: The automatic feed function also needs to consider safety. Systems are usually designed with safety protection mechanisms to avoid collisions or other accidents. This may include emergency stop functionality, sensor monitoring, etc.

6. Multi-step feed: For complex processing tasks, automatic feed usually supports the function of multi-step feed. This means that the system can gradually complete the cutting process according to predetermined steps, ensuring that each step is carried out under safe and precise control.

7. User interface: The operator can set and adjust the parameters of automatic feed through the user interface of the CNC system. This makes operation more flexible and convenient.

The introduction of the automatic feed function has greatly improved the automation level of CNC machining centers, making the processing process more intelligent and efficient. At the same time, it also helps to improve processing accuracy and reduce the impact of human factors on processing quality.