Hydraulic valve hydraulic valve unloading

Unloading valve is under certain conditions, to make the hydraulic pump unloading valve. Unloading valve is usually a two-way valve with two (usually solenoid valve) relief valve function is used to set the system (pump) without unloading the main pressure, when the unloading state (two by two pass valve operation conversion) pressure oil directly back to the tank, the pump pressure drops to approximately zero, in order to achieve some loop control and improve pump life and reduces power consumption. It is incorporated belonging to the loop in the loop. Valve actuator for adjusting the desired pressure is connected in series in the loop, generally can not be used interchangeably.

principle

Unloading relief valve by the pressure relief valve and check valve. When the system pressure reaches the relief valve opening pressure relief valve to open, pump unloading; When the system pressure is reduced to a pressure relief valve closed, the relief valve is closed, the pump is loaded to the system. Pressure pump unloading when called unloading pressure, the pump in a loaded condition called load pressure.

Features

Unloading relief valve main function is automatic control of pump unloading or loading. Given unloading relief valve function, there are some differences between the requirements for unloading and loading load stress pressure. The difference is too small, the pump unloading and loading operation too frequently; the difference is too large, the system changed so much pressure.

Loading and unloading the pressure difference between the pressure relief valve is unloading an important performance indicators, generally about 85% of the load pressure unloading pressure. Its performance and the same relief.

The main purpose of the relief valve discharge:

. A system accumulator pump automatic loading and unloading;

b. a combination of high and low pressure pump high flow low pressure pump unloading.