Maintenance skills of the hottest universal millin

Maintenance skills of universal milling machine

① when the universal milling machine is disconnected from the power supply, use the multimeter resistance block to measure the coil resistance of contactor KM3. If the coil is disconnected or the resistance is very small, it should be judged that the contactor coil is burned out. The contactor coil of the same model can be replaced according to the existing conditions, and the contactor can also be replaced

② measure the normally closed contact of km2 interlock connected in series by the coil of contactor KM3 with the multimeter resistance gear when disconnecting the power supply of the universal milling machine. If it is not closed well, check whether the contact is poor and whether the contact fusion welding cannot be completely reset. If the contact is poor, repair the friction connection. 3. Detect and control the normally closed contact of the contact; If the contact fusion welding of km2 contactor cannot be reset, try to separate the contact to reset the km2 contactor

③ check whether the fuse Fu3 of the control line at the beginning of the year is not tightened and cannot be contacted. Measure both ends of Fu3 with a multimeter resistor when the power supply is disconnected. If there is an open circuit, check whether it is in poor contact or fused; If it is fused, replace the fuse with the same specification

④ measure a group of normally closed contacts of the spindle speed change instantaneous switch with the multimeter resistance gear when the power supply is disconnected. If the contact is poor or the circuit is open, repair it. If the damage is serious, replace the button sq7

⑤ disconnect the power supply and use the multimeter resistance block to measure whether Sb3 or Sb4 has poor contact or poor closure. If it is found that the contact and closure of button Sb3 or Sb4 are poor, replace the button of the same model

⑥ in the case of power failure, press the operation button, use the multimeter resistance block to measure whether SB1 and SB2 are connected reliably, and find out which button is not connected well or cannot be accessed after pressing, and replace the button for the next 3 years

⑦ carefully check whether the joints of the control circuit of the milling machine are burnt out or have poor contact due to vibration. If it is found that a joint is not in good contact, it is necessary to re compress the joint

⑧ check whether the self-locking point of contactor KM3 has poor contact. If it is difficult to see visually, the following two methods can be used to test and judge: ① connect the power supply and operate the spindle motor. If the contactor can pull in and automatically shut down after releasing the button, it indicates that the self-locking point has poor contact. ② You can also use a multimeter to open the arc extinguishing cover of the contactor when the power is disconnected, and use the screwdriver handle to manually make the contactor close. At this time, measure whether the self-locking point of the contactor KM3 can be closed. If it is not closed well, polish the KM3 auxiliary contact with fine sandpaper or repair the contact

⑨ use a multimeter to test the resistance of the primary and secondary coils of T1 control transformer when the milling machine is disconnected. If the circuit is burnt out or the resistance is very small, it means that the control transformer is burnt out, and the control transformer of the same specification should be replaced. If it is not clear whether the transformer is burnt out at the moment, it can also be measured while vibrating. The power supply can be connected to measure the transformer voltage. The primary control voltage should be 380V, and the secondary control voltage should be 127V. If there is no voltage or the voltage is abnormal, it indicates that transformer T1 has been burnt out. If the wire end of the transformer is burnt out or in poor contact, it can continue to be used after corresponding treatment

⑩ measure whether there is voltage at the lower pile head of fu1 and fu2 with a low-voltage electric pen. If there is no voltage at all, measure the upper pile head. If there is still no voltage, it means that the line is powered off, and the reason should be found from the line. If there is voltage in one or two phases of the pile head, check the fuse fu1. If the contact is poor, press the safety tightly; If the fuse is blown, replace the fuse of the same specification