Dec. 04, 2025
Common Faults and Troubleshooting Methods for Vertical CNC Lathes
Vertical CNC Lathe Fault Phenomenon | Cause | Troubleshooting Method
1. Malfunction
1. Loose or incorrect electrical wiring.
2. Insufficient oil supply.
3. System fails to build up pressure.
4. Check the circuit.
5. Add oil to the oil level indicator.
6. Disassemble and clean some cartridge valves.
2. Slide creep
1. Air accumulation in the system or air entering the oil pump suction port.
2. Improper precision adjustment and insuficient lubrication in the column.
3. Check for air entering the suction pipe, then run the machine up and down several times while pressurizing to expel the air.
4. Add oil to the column oil cup or readjust the precision.
3. Excessive pressure during slow slide descent
1. Excessive support pressure.
2. The piston valve core of the hydraulic check valve (lower block) is stuck.
3. Adjust the support pressure so that the maximum blank holder force does not exceed 2MPa during slow descent. 4. Repair and lap joint.
4. Severe sliding of the slider after shutdown.
1. Leakage of the cylinder port seal.
2. Leakage of the lower hydraulic control check valve and valve plate.
3. Inspect the cylinder port; replace if leakage is found.
4. Inspect the valve port and lap joint.
5. Pressure gauge pointer swings violently.
1. Pressure gauge switch is not properly adjusted.
2. Pressure gauge is damaged. Adjust (reduce opening amount).
3. Replace the pressure gauge.
6. Insufficient high-pressure stroke speed, slow pressure build-up.
1. Poor agitation.
2. Pump wear or burn.
3. Severe internal leakage in the system.
4. Check its sealing performance.
5. If the pump's return oil leakage exceeds 4 liters/hour, it should be disassembled and inspected.
6. First, check if any seals are damaged.
7. Pressure drops too quickly during pressure holding:
1. Valves involved in pressure holding are not tight or there is oil leakage in the pipeline.
2. Internal cylinder seals are damaged.
3. Inspect the wave-charging valve, the hydraulic control check valve on the upper block, and the flue gas port; replace the seals.
4. Replace the seals.
