This system is the actuator of the concrete fine stone pump, which is used to continuously transport the concrete mixture along the conveying pipeline to the pouring site. Under normal circumstances, the pumping conditions of concrete fine stone pumps have two delivery modes: high pressure and small displacement and low pressure and large displacement. Users can make reasonable choices based on the requirements of the project for concrete delivery height (or distance) and displacement. The switching methods of high pressure and low pressure include replacing hoses, rotating valve block positions, and manual reversing valves. Most of the newly developed products have adopted fully automatic high and low pressure switching technology. By turning the electric control button, the high and low pressure switching can be completed in an instant, which is quick and convenient. In addition, new products also use automatic piston retraction technology. With just one click of a button, the concrete piston can be retracted into the water tank. This technology can greatly shorten the time for installing and disassembling the concrete piston and reduce the labor intensity of the operator. At the same time, the concrete piston can be retracted at any necessary time to check the wear of the concrete seal, or to clean and maintain it, thereby extending the service life of the piston.

(2) Hydraulic and electronic control systems

Hydraulic systems include open systems and closed systems. The open system has the advantages of low hydraulic oil temperature and high cleanliness; the closed system has the advantages of a small hydraulic oil tank and a compact structure. Most domestic products use these two systems. The electronic control system generally uses PLC control. Some products are also equipped with text displays and touch buttons, which have a good human-computer interaction interface. The monitors distributed in various parts of the concrete fine stone pump send signals to the PLC controller, and the PLC controller displays the working status of the concrete fine stone pump through the text display. When an abnormality is encountered, the protection program built into the system is immediately activated to protect the concrete fine stone pump from damage. At the same time, the cause of the fault is displayed on the text display, which can facilitate fault diagnosis and maintenance.

The power source of the towed concrete fine stone pump is either a diesel engine or an electric motor. The diesel engine pump has the advantage of strong adaptability. In some construction sites, the power supply cannot meet the machine's requirements for high power. Because the large-displacement concrete fine stone pump generally requires a power of more than 100kW, the diesel engine does not need to consider the power supply problem. This is why diesel engine pumps have always been favored by users. The advantage of the electric motor pump is that it is low in price and has low noise. For urban construction with increasingly high environmental protection requirements, the electric motor pump is undoubtedly more suitable.