Truck-mounted concrete pump, referred to as truck-mounted pump, refers to the concrete pumping equipment that installs the pumping mechanism for pumping concrete on the chassis of the car. Therefore, it has the function of driving and pumping concrete. It is mainly used to complete the following tasks: ①Concreting construction of buildings and factories; ②Concreting construction of roads, overpasses and bridges; ③Concreting construction of airports, rail transit and tunnels. The hydraulic system adopts a large-diameter, large-flow spool valve type structure reversing valve. When reversing, the excess flow of the main oil pump is introduced into the swing valve system, which can greatly reduce the reversing pressure loss and the impact of the hydraulic system, and improve the response speed and pumping of the swing valve Continuity makes efficiency higher.