The spindle of the machine tool refers to the axis on the machine tool that drives the workpiece or tool to rotate. The machine tool spindle is usually composed of a spindle, bearings and transmission parts (gears or pulley).
There are two main types of high-speed spindles in practical applications:
1. High-speed motorized spindle with zero transmission
This kind of spindle because of the integration of motor and machine tool spindle structure, and after accurate dynamic balance correction, so it has good rotation accuracy and stability, but the output torque and power are limited.
2. Spindle with frequency conversion spindle motor combined with mechanical variable speed mechanism
The torque and power output of this type of spindle is much larger, but the rotation accuracy and smoothness are relatively poor, so for this type of spindle, how to correctly design the impact of the machine tool spindle and its components on the machining accuracy of the machine tool is crucial.
CNC machine tool spindle common faults and solutions:
1. The spindle without frequency conversion does not turn
Fault cause and solution:
① Caused by mechanical transmission failure: check whether the belt drive is broken or whether the machine tool is in neutral gear.
② The three-phase power supply to the main shaft lacks phase or reverse phase: check the power supply and replace any two power lines.
③ Circuit connection error: carefully refer to the circuit connection manual to ensure that the connection is correct.
④ The system has no corresponding spindle control signal output: use a multimeter to measure the system signal output. If there is no spindle control signal output, it is necessary to replace the relevant IC components or send them to the factory for maintenance.
⑤ The system has the corresponding spindle control signal output, but the power supply line and the control signal output line are disconnected or the components are damaged: Use a multimeter to check the power supply loop between the system and the spindle motor, and whether the signal control loop is disconnected; Whether there is a break; Whether the contacts between the wires are in poor contact; Ac contactor, DC relay is damaged; Check whether the thermal relay is overcurrent; Check whether the fuse is burned, etc.
2. Spindle with inverter does not turn
Fault cause and solution:
① Caused by mechanical transmission failure: check whether the belt drive is broken or whether the machine tool is in neutral gear.
② The three-phase power supply to the main shaft is out of phase: check the power supply and replace any two power lines.
③ The inverter control parameters of the CNC system are not opened: consult the system manual, understand the frequency conversion parameters and change them.
④ The line connection between the system and the inverter is wrong: consult the connection manual between the system and the inverter to ensure the correct connection.
⑤ The analog voltage output is abnormal: use a multimeter to check whether the analog voltage output of the system is normal; Check whether the analog voltage signal line is correctly connected or has poor contact, and whether the analog voltage received by the inverter matches.
⑥ Strong power control partial break or component damage: check whether the contact connection of the main shaft power supply line is reliable, whether the line is broken, whether the DC relay is damaged, whether the safety tube is burned out.
⑦ Frequency converter parameters are not adjusted: the frequency converter contains control mode selection, which is divided into frequency converter panel control spindle mode, NC system control spindle mode, etc. If you do not select NC system control mode, you can not use the system control spindle, modify this parameter; Check whether the related parameters are properly set.
3. Shift spindle speed is not controlled without frequency conversion
Troubleshooting method of the fault cause:
① The system has no S01-S04 control signal output: Check whether the system has no shift control signal output. If no, the system is faulty. Replace the IC or send it to the factory for maintenance.
(2) Connection line fault: If the system has a shift control signal output, check whether the connected line is open or in poor contact, check whether the DC relay or AC contactor is damaged.
③ Spindle motor damage or short circuit: check the spindle motor.
④ Mechanical not in gear: hang the gear.
4. Spindle without brake
Troubleshooting method of the fault cause:
① Abnormal braking circuit or damage of strong electric components: check whether the bridge pile, fuse, AC contactor is damaged; Check whether the strong circuit is open.
② Braking time is not long enough: Adjust the braking time parameters of the system or frequency converter.
③ The system has no brake signal output: replace the internal components or send to the factory for maintenance.
④ Frequency converter control parameters are not adjusted: check the frequency converter instruction manual and set the frequency converter parameters correctly.
5. Stop the spindle immediately after starting
Troubleshooting method of the fault cause:
① The system output pulse time is not enough: adjust the system's M code output time.
② The inverter is in the point state: refer to the operation manual of the inverter and set the parameters.
③ The control components of the main shaft line are damaged: check whether the contacts on the circuit are in good contact, check whether the AC contactor of the DC relay is damaged, resulting in the contact not self-locking.
④ spindle motor short circuit, resulting in thermal relay protection: find the cause of short circuit, so that the thermal relay reset.
⑤ The spindle control loop does not have a self-locking circuit, and the parameters are set to pulse signal output, so that the spindle can not operate normally: change the system control spindle start-stop parameters to level control mode.
6. Spindle rotation can not be stopped
Troubleshooting method of the fault cause:
Ac contactor or DC relay is damaged, prolonged suction, cannot be controlled: Replace AC contactor or DC relay