Analysis of troubleshooting of CNC lathe electric tool post

Since CNC lathe's electric tool post is the main configuration of CNC lathe, it plays a very important role in the operation of the machine tool, so many times when the electric tool post fails, it will bring a lot of trouble to the work, and may cause the workpiece to be scrapped, or even In severe cases, it may cause collision between the chuck and the tool holder. In the process of repairing the machine tool, the fault phenomenon is changeable. Occasionally, the circuit of the electrical control part is complicated. However, the mechanical part is similar to the ordinary machine tool, so the fault is relatively easy to eliminate.

The electric tool post generally has four or six stations, and consists of a motor, a mechanical tool changer, and a sending plate. When the system sends a tool change signal, when the tool post motor is rotating in the forward state, the upper tool body will be raised to the designated position through the deceleration mechanism and the lifting mechanism, and then the upper tool body will be driven to rotate to the selected tool position through the clutch disc. When the sending plate sends out the tool position signal and the tool post motor is in reverse state, the upper tool body will drop after the initial positioning is completed, the precise positioning is completed after the chainring is engaged, and the tool post is locked by the lifting mechanism. The following is a brief description of the phenomenon when the tool holder fails:

1. For the fault that the tool post does not change the tool, first determine whether it is the internal mechanical problem of the tool post or the fault of the tool post motor. When changing the tool, you need to touch the motor with your hand to check whether there is vibration and measure the voltage of the motor, so as to judge whether the motor is malfunctioning. If the motor is normal, it is a mechanical problem. In most cases, the inside of the knife holder is mechanically stuck. Just remove the knife holder, clean it, and reinstall it. But sometimes it may be internal mechanical damage.

2. In view of the failure of the tool holder not being tightly locked, generally the tool holder anti-locking time in the machine parameters may be set too short, or it may be that the tool holder internal lock nut is too loose, or it may be the Hall element of the sending plate The position is not aligned with the magnet.

3. Regarding the tool position that cannot be found in the CNC lathe, the tool holder rotates continuously. This problem may generally be caused by a problem with the tool holder’s transmitter board or the tool position signal receiving circuit of the CNC system. It may also be the problem of communication line failure.

4. When the No. 1 tool of CNC lathe cannot be found, and other tool positions can be changed normally, it may be that the Hall element of the tool post's transmitter plate is offset or the Hall element of the No. knife is damaged. Or the signal line section of the tool position. Of course, the first two failures are usually caused by mechanical reasons, which are easier to judge and repair, but the latter two failures are caused by electrical reasons.