How to solve the problem of the tailstock of a CNC lathe not being locked tightly?

Loose locking of the tailstock of a CNC lathe is a common fault, which may be caused by mechanical, electrical or hydraulic system issues. The following are the specific solutions

Ⅰ. Inspection and Adjustment of Mechanical Structure

1. Handle tailstock adjustment ‌

If the tailstock handle cannot be locked after being pulled up, the three nuts at the bottom need to be adjusted

The nut near the headstock needs to be tightened

The nut at the middle fulcrum is slightly loosened

The bottom handle connection nut is looser than the middle nut

Clamping is achieved through the lever principle and needs to be repeatedly adjusted until the locking is flexible ‌

2. Maintenance of guide rails and lead screws ‌

Check whether the lubrication of the tailstock guide rail is sufficient, whether the lead screw bearing is stuck, and whether the pressure of the balance bar is normal. If there is an imbalance in mechanical resistance, the moving parts ‌ need to be cleaned and lubricated

Ⅱ. Inspection of the electrical control System

1. PLC parameter and signal detection ‌

Check the delay timer parameters of the tailstock release solenoid valve. If the original set value is 0, it will cause the locking mechanism to not be fully released. It is recommended to adjust it to 15 seconds ‌

Check the lock detection switch signal (such as whether X2.6TCP is 1). If the signal is abnormal, adjust the height of the pressure plate or replace the damaged switch ‌

2.pressure relay fault ‌

If the contact of the pressure relay in the hydraulic system is damaged, it will cause the PLC to misjudge that the tailstock is not tightened. The relay needs to be replaced and the contact pressure adjusted to ensure the normal transmission of the oil pressure signal ‌

Ⅲ. Optimization of Hydraulic System

1.Pressure stability treatment ‌

The "three quantities" analysis method (oil volume, gas volume, and leakage volume) is adopted to investigate the problem of unstable pressure in the hydraulic system, with a focus on checking whether the relief valve, flow control valve, and check valve are leaking.

2. Load sensing control ‌

Optimize energy efficiency, reduce system energy consumption and improve dynamic response speed by working in coordination with variable displacement pumps and accumulators.

Iv. Daily Maintenance Suggestions

Regularly clean the tailstock guide rail to avoid chip accumulation affecting locking ‌

When processing, avoid the tailstock ejection pin being too tight. Reserve space for thermal expansion. After processing, loosen the handle in time to release stress ‌

Regularly change the oil in the hydraulic system and keep the oil passage clean.