Talking about the Case Analysis of Small CNC Lathe Turret
Small CNC lathe tool change the general process is: after the tool changer receives the tool change signal, it drives the turret to rotate through the reduction of the worm gear, the tool position signal is sent out by the Hall element, and the CNC system uses this signal to compare with the target value Judge the tool is in place. After the knife is changed to position, the motor reversely tightens the tool post.
Fault 1: a six-knife small CNC lathe, tool change when all the knife can not find the turret rotation after a few weeks to stop, and the CNC system shows the tool change alarm: Tool change overtime or no signal input.
Failure Analysis: For the fault, you can still rule out mechanical failure, due to electrical fault. The electrical causes of the failure are the following: ① magnetic components off; ② all six Hall element damage at the same time; ③ Hall element power supply and signal lines open lead to no voltage signal output. The third reason is most likely. So find the circuit diagram, the use of multimeter on the Hall element electrical lines to check the power supply line. The results showed that: 24V supply voltage on the terminal block of the tool-holder testing line was 0V, and other lines were normal. Find the clues along the line and found that the 24V thread led off from the electrical cabinet fell off and still no response after connecting. Judgment should be the fault caused by the line disconnection.
Solution: Use the same specifications wire instead of broken, troubleshooting.
Fault 2: A four-knife small CNC lathe, one knife position can not be found, the other knife can be a normal tool change fault phenomenon.
Failure Analysis: As only one knife can not find the knife position, you can rule out mechanical transmission problems, to determine the electrical fault. It may be the location of the Hall element and the surrounding line problems, resulting in the cutter signal can not be sent to plc. Check the use of multimeter circuit diagram found that: Hall No. 1 cutter Hall element 24V power supply is normal, GND line is normal, T1 signal line is normal. Therefore, we can conclude that the Hall element damage caused by the knife position signal can not be issued.