Pressure control valve is divided into uses by relief valve? Pressure relief valve and sequence valve. (1) relief valve: can control the hydraulic system to maintain a fixed pressure? A set state. The relief valve used for overload protection is called safety valve. When the system fails, the pressure? N up to the limit may cause damage, the valve will open and overflow, in order to ensure the safety of the system. (2) pressure reducing valve: can control the branch road to get lower than the main road hydraulic pressure stability. Pressure relief valve according to its control of different pressure functions, but also can be divided into fixed value pressure relief valve (output pressure? A fixed value)? Differential pressure relief valve (input and output pressure differential for the fixed value) Pressure valve (input and output pressure to maintain a certain ratio). (3) sequence valve: can make an actuator (such as hydraulic cylinder? Hydraulic motor, etc.) action, then the order of the other actuator action. The pressure of the oil pump first promotes the movement of the hydraulic cylinder 1 and at the same time it acts on the area A through the inlet of the sequence valve. When the hydraulic cylinder 1 is completely moved, the pressure N is high, and the upward thrust acting on the area A is greater than that of the spring Set value, the spool? N so that the oil inlet and outlet connected to the hydraulic cylinder 2 movement. The flow control valve regulates the flow rate by adjusting the orifice area between the valve plug and the valve body and the local resistance generated by it, so as to control the movement speed of the actuator. Flow control valve is divided into 5 uses. (1) Throttle valve: After setting the orifice area, the moving speed of the actuator capable of little change of load pressure and less demanding of uniformity of motion can be kept basically stable. (2) speed control valve: When the load pressure changes to maintain the throttle valve inlet and outlet differential pressure for a fixed value. In this way, after adjusting the orifice area, the speed control valve can keep the flow through the throttle valve unchanged, so that the movement speed of the actuator is stable. (3) Divertervalve: Regardless of the load, equal flow diverter valves or synchronous valves can be obtained by equalizing the two actuators of the same oil source. (4) the collection valve: the role of the bypass valve and the opposite, so that the flow into the collection valve in proportion to the distribution. (5) shunt manifold valve: both divert valve and current collector valve two functions. Directional control valve is divided into use by one-way valve and the valve. Check valve: Only allow the fluid in the pipeline unidirectional connected, the reverse that cut off. Change the valve: change the line between the different off? S? According to the spool in the valve body working position divided into two digits? Three, etc.; According to the number of channels divided into two links? Three? Four Pass through five links, etc .; according to the spool drive sub-manual? Mobile? Electro-hydraulic and so on. When the valve core is in the middle, all the oil ports are cut off and the actuator does not move; when the valve spool is moved to the right position, P and A pass, B and O pass; when the valve spool moves to the left, P and B Pass, A and O pass. In this way, the actuator can make positive and reverse movement.
Bimetallic Twin Screw and Barrel
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