hydraulic control valve

Hydraulic fluid used to control the pressure, flow and direction components. Wherein the control pressure is called pressure control valve to control the flow of known flow control valve to control the communication, the direction is called off and the flow control valvePressure control valve use is divided into relief valve, pressure reducing valve and sequence valve. ① relief: to control the hydraulic system reaches the set pressure to maintain a constant state. Called safety valve relief valveHydraulic tube fittings. When the system fails, the pressure rises to potentially damaging limit, will open the overflow valve port to ensure system security. ② valve: branch circuit to control oil pressure than is the stability of the main circuit pressure. It controls the pressure reducing valve according to different functions can be divided into fixed value regulator (output pressure at a constant value), fixed differential pressure relief valve (pressure difference between the input and the output is a fixed value) and fixed ratio valve (between input Hydraulic adapters to maintain a certain percentage). ③ sequence valve: allows an actuator (such as hydraulic cylinders, hydraulic motors, etc.) after the action, and then in order to enable other actuator action. Figure 1 shows the sequence valve works. Pump pressure generated by the hydraulic cylinder 1 is first push motion, through the sequence valve in the inlet acting on the area A, when the hydraulic cylinder 1 is completely into motion, the pressure rise, acting on the area A is greater than the upward force of the spring it is set value, the spool up the inlet and outlet port connected to the hydraulic cylinder 2 motion.