Abstract

Background: The master cylinder of heavy hydraulic press commonly used multi-stage pressure relief to ensure that hydraulic oil of master cylinder flows into tank without impact.

Objective: In order to easily, safely and reliably implement this function, a multi-stage pressure relief valve with hydraulic resistance network was designed.

Methods: This valve can steadily reduce the pressure of master cylinder through matching several hydraulic resistances which only need one switch valve. Through expanding analysis, two-stage pressure relief structure was generalized to N-stage structure which can control the process of pressure relief on demand.

Results: The AMESim simulation models of multi-stage pressure relief valve were established and the simulation results were analyzed. This valve can effectively control multi-stage pressure relief and ensure high-pressure chamber relieves pressure without impact. The valve provides a secure and reliable pressure relief plan for heavy hydraulic presses.

Conclusion: This paper proposed the two-stage pressure relief theory based on the hydraulic resistance theory and extended it to the N-stage pressure relief. If system increases one module, the pressure release rate will change one more time, which is well adaptable. Besides the multi-pressure relief valve which is based on the pressure relief theory can realize the function of the high flow balance and adaptable pressure relief. According to the mathematical modeling and simulations, the increasing hole diameter of the throttle valves can make the former pressure relief rate get close to the latter. When the hole diameter is large enough, there will be no break of the pressure relief rate. As the diameter of the damping hole increases, the first pressure relief rate slows down, however, the whole pressure relief time is prolonged.

Keywords: AMESim simulation, hydraulic resistance network, multi-stage pressure relief, pressure relief circuits.