Supply Rexroth relief valve

  Overflow valve is a kind of hydraulic pressure control valve, which mainly plays the role of constant pressure overflow, pressure stabilization, system unloading and safety protection in hydraulic equipment Function of overflow valve Constant pressure overflow function: in the throttling regulation system of quantitative pump, the quantitative pump provides constant flow
When the system pressure increases, the flow demand decreases
At this time, the overflow valve is opened to overflow the excess flow back to the oil tank and keep the inlet pressure of the overflow valve, that is, the pump outlet pressure constant (the valve port is often opened with pressure fluctuation) Pressure stabilizing effect: the overflow valve is connected in series on the oil return road, the overflow valve generates back pressure and the stability of moving parts is increased System unloading function: the solenoid valve with small overflow flow is connected in series at the remote control port of the overflow valve
When the solenoid iron is energized, the remote control port of the overflow valve is connected to the oil tank, and the hydraulic pump is unloaded
The overflow valve is now used as a unloading valve Safety protection function: when the system works normally, the valve is closed
Only when the load exceeds the specified limit (the system pressure exceeds the set pressure), open the overflow for overload protection, so that the system pressure will not increase (usually the set pressure of the overflow valve is 10% ~ 20% higher than the system working pressure) In practical application, it is generally used as unloading valve, remote pressure regulating valve, high and low pressure multi-stage control valve and sequence valve to generate back pressure (in series on the oil return road) Overflow valve generally has two structures: 1
Direct acting overflow valve
2
Pilot operated relief valve Main requirements for overflow valve: large pressure regulation range, small pressure regulation deviation, small pressure swing, sensitive action, large overload capacity and low noise