This system uses hydraulic driving, pressure and displacement closed-loop automatic control mode to realize multi-point control, widely used in replacement of highway bridge rubber bearings, overpass lifting, synchronous lifting of inland river bridge, equipment lifting and rectification etc. System Composition and Main Principle
This system is composed of 1 high pressure pump station, control valve groups, hydraulic cylinders, stroke monitoring devices, pressure monitoring devices and 1 set of electrical control system.
Hydraulic pump station controls the flow by on-off valve, depending on regulating the switch frequency to change the flow which achieves the purpose of output flow can be regulated continuously. Accurate control on the synchronization of each hydraulic cylinder in lifting and load balancing in weighing process can be achieved by matching with proper electric control device, to compose pressure and displacement closed-loop control. Structure Descriptions
Plunger hydraulic pump equipped with balance valves, guarantee hydraulic cylinders in oil-taking speed control when lifting and lowering, alleviate the effects of hydraulic impact on the synchronous accuracy, can lock the hydraulic cylinders without leakage, ensure hydraulic cylinders will not fall freely in case of accidental power failure and make the load of the hydraulic cylinder will not be out of control. This system is also equipped with pressure transducer and displacement sensor. When the hydraulic cylinder lifting, the pressure detection device can monitor the load weight in real time. At the same time, the displacement detection device can measure lifting height of hydraulic cylinders in real time.
The characteristics of the electric control system is mainly composed of SIEMENS PLC controller, signal is sent to PLC for monitoring by pressure sensor and displacement sensor of each cylinder. According to the instructions sent from master control station, driving valve group, output pressure oil to make the corresponding hydraulic cylinder lifting or lowering. According to the detected pressure value and displacement value, PLC continuously correct the displacement error and keep the synchronization of each load.
