Hydraulic valve Throttle valve threaded cartridge valve LF12 Flow control valve LNV-12

    The threaded cartridge valve is a rotary mounted cartridge valve, which is screwed into the threaded hole of the oil block by the plug-in with its own thread (as shown)  so that the composition of the hydraulic system structure is more compact, its volume is smaller, lighter weight, screw thread on the seal to form a tight seal can ensure that the hydraulic system does not leak oil. Therefore, because of its zero leakage, high unit volume density, small space, easy to disassemble and replace, cost-effective, can be directly connected with the actuator (such as hydraulic cylinder, motor) import and export part, easy installation and debugging and other advantages, by the domestic and foreign hydraulic industry attention. Figure 2 shows the typical application of Vickers screw insert valve in concrete pumping device of Sany Construction Machinery. Its working principle is shown in FIG. 1.b. When the piston is about to reach the end point and cross port A, due to the damping effect of the damping hole, a pressure difference is formed at both ends of the cartridge valve spool, so that port C provides reversing control oil, and then through the damping of the oil drain valve, the pressure is built to drive the pilot small hydraulic valve of the swing four-way valve, resulting in the reversal of the swing valve and complete the concrete pumping Half a cycle of hydraulic commutation.
 

  Since SANY concrete pumping engineering machinery adopts a single loop hydraulic system (that is, the concrete distribution valve cylinder and the pumping cylinder are in the same loop), the key of this system is how to realize the automatic sequential action of the concrete distribution valve cylinder and the pumping master cylinder, so the two main cylinders of the pumping device of Sany drag pump and pump truck are equipped with threaded cartridge valves (Figure 2.). Provide pressure control signal, so that the concrete pumping operation in the process of accurate and timely, that is, the hydraulic system itself to complete the pump master cylinder and the distribution valve cylinder of the alternate commutation of the full hydraulic commutation cycle, smoothly realize the suction and feeding operation Ring.