In CNC programming, the code representing the fixed cycle function is a series of specific G codes, which are used to control the machine tool to perform repeated processing actions, such as drilling, boring, tapping, etc.
The fixed cycle function can simplify the programming process and improve processing efficiency. The following are some commonly used G codes representing the fixed cycle function and their brief descriptions:
1. G81: Drilling fixed cycle instruction. The spindle rotates forward, and the tool moves downward at the feed speed to drill the hole. After reaching the bottom of the hole, it quickly retracts without bottom of hole action.
2. G82: Drilling fixed cycle instruction with bottom of hole pause. The main difference from G81 is that the feed pause action is added at the bottom of the hole to make the surface of the hole smoother.
3. G73: High-speed deep hole drilling fixed cycle instruction. Intermittent feeding is used to facilitate chip removal, which is particularly suitable for deep hole processing.
4. G83: Deep hole drilling fixed cycle instruction. Similar to G73, but it returns to the R point plane after each feed, which is particularly beneficial for chip removal during deep hole drilling.
5. G84: tapping fixed cycle instruction. The spindle feeds forward and reverses when exiting. The tapping process requires that the spindle speed and feed speed are strictly proportional.
6. G85: boring fixed cycle instruction. The spindle rotates forward, and the tool moves downward at the feed speed to bore the hole. After reaching the bottom of the hole, it exits at the feed speed immediately without bottom of hole action.
7. G89: In some CNC systems, G89 is also used as a boring fixed cycle instruction, but its specific actions may be different from G85, such as a pause action at the bottom of the hole.
It should be noted that different CNC systems may vary, and the specific meaning and usage of the above G codes may need to be adjusted according to the CNC system used.
In addition, with the continuous development of CNC technology, new fixed cycle instructions may also be introduced.
Therefore, when programming, it is recommended to consult the programming manual of the CNC system used or consult relevant technicians to ensure that these fixed cycle instructions are correctly understood and used.