Add: Mechanical&Electrical Industry Zone,Yuhuan,Zhejiang,China
Hydraulic valve is a pressure oil operated by the automatic components, which is controlled by the pressure valve oil pressure, usually combined with the use of electromagnetic pressure valve can be used for long-distance control of hydropower station oil, gas, water pipe system off. Commonly used in clamping, control, lubrication and other oil. There are direct and pilot type of the points, multi-use pilot type.
According to the use of one-way valve and valve. Check valve: only allows the fluid in the pipeline in one direction, reverse that cut off. Directional valve: change the relationship between the different piping. According to the number of working places in the valve body in two parts, three, etc .; according to the number of channels controlled by the two links, three links, four links, five links, etc .; according to the spool drive way manual, , Hydraulic and so on. Figure 2 for the three four-way valve works. P is the oil supply port, O is the return port, and A and B are the output ports leading to the actuator. When the spool is in the middle position, all the port cut off, the implementation of the component does not move; when the spool moved to the right position, P and A, B and O through; when the spool to the left position, P and B Pass, A and O pass. In this way, the implementation of components can be positive and negative movement.
In the late 1960s, electro-hydraulic proportional control valves were developed on the basis of several hydraulic control valves. Its output (pressure, flow) can be continuously changed with the input electrical signal. Electro-hydraulic proportional control valve according to the role of different, correspondingly divided into electro-hydraulic proportional pressure control valve, electro-hydraulic proportional flow control valve and electro-hydraulic proportional directional control valve.
According to the use of overflow valve, pressure relief valve and sequence valve. ⑴ relief valve: to control the hydraulic system to achieve the set pressure to maintain a constant state. A relief valve for overload protection is called a safety valve. When the system fails, the pressure rises to the limit may cause damage, the valve port will open and overflow to ensure the safety of the system. ⑵ pressure reducing valve: can control the branch circuit to get lower than the main circuit pressure pressure. The pressure relief valve according to its control of the pressure function is different, but also can be divided into constant pressure valve (output pressure is constant) ﹑ differential pressure reducing valve (input and output pressure difference is set) and the ratio of pressure reducing valve (Input and output pressure to maintain a certain proportion). ⑶ sequence valve: can make an implementation of components (such as hydraulic cylinders, hydraulic motors, etc.) after the action, and then in order to make other executive elements. The pressure generated by the pump first to promote the movement of the hydraulic cylinder 1, while the inlet valve through the sequence of action on the area A, when the hydraulic cylinder 1 is fully completed, the pressure increases, the role of the area of the upward thrust greater than the spring Value, the spool up so that the inlet and outlet port connected to the hydraulic cylinder 2 movement.
The flow rate is adjusted by adjusting the area of the orifice between the valve plug and the valve body and the local resistance it generates to control the speed of movement of the actuator. The flow control valve is divided into five types according to its application. ⑴ throttle valve: in the adjustment of the orifice area, can make the load pressure is not changed and the movement uniformity of the requirements of the implementation of the components of the speed is basically stable. ⑵ speed control valve: in the load pressure changes can keep the throttle valve inlet and outlet pressure for the fixed value. In this way, after the throttle area is set, regardless of how the load pressure changes, the governor can keep the flow through the throttle constant, thus stabilizing the speed of the actuator. ⑶ diversion valve: regardless of the size of the load, can make the same oil source of the two actuators are equal flow equal to the diversion valve or synchronous valve; get proportional distribution of the proportion of flow distribution valve. ⑷ current valve: the role of the opposite with the diversion valve, so that the flow into the flow of the proportion of the distribution valve. ⑸ shunt flow valve: both flow distribution valve and two functions.
1) flexible action, the role of reliable, the impact of work and vibration small, low noise, long service life.
2) When the fluid passes through the hydraulic valve, the pressure loss is small; when the valve port is closed, the sealing performance is good, the internal leakage is small, no external leakage.
3) The controlled parameters (pressure or flow) are stable and subject to external disturbances.
4) compact, installation, commissioning, use, easy maintenance, good versatility