The bottom of the cup punched by the hydraulic press is too soft, which is caused by the unstable system pressure, and the system pressure cannot be added at all. The screw for adjusting pressure loosens the lock nut due to vibration, resulting in pressure fluctuation, dirty hydraulic oil and tiny dust, which makes the main spool slide inflexible and causes irregular pressure change. Sometimes the valves will get stuck, and the assembly quality is poor, and the assembly accuracy is poor. The gap between the valves is not adjusted well, and the main valve core is stuck in the open position, which will lead to poor assembly quality and too soft cup bottom.