Operating principle:
This PLC-based six-point synchronous jacking system utilizes hydraulic variable-frequency speed control and closed-loop automatic pressure and displacement control to achieve multi-point force balancing. This system allows for weighing, simultaneous pushing, lifting, and lowering of large structures, achieving a maximum synchronous lifting accuracy of ±0.5mm. The system’s hydraulic pump station utilizes a valve-controlled plunger pump, and a balanced load-sharing valve is installed on the cylinder. This ensures that the jacks maintain oil flow control during both raising and lowering, mitigating the impact of hydraulic shock during the jack-raising and lowering transitions on the jacking synchronization accuracy and the structure’s structure. The load-sharing valve also provides a leak-proof lock on the jacks, preventing them from sliding freely in the event of a power outage, ensuring that the load they support remains uncontrolled. The system also incorporates pressure and displacement sensors. The pressure sensor accurately measures the load on the jacks in real time as they move, while the displacement sensor measures the actual lifting height of the structure.
The basic functions are described as follows:
①. The hydraulic pump station of this control system has six control points and is equipped with a wireless remote control compatible with the control system.
②. The system is equipped with six 282-ton double-acting hydraulic lifting jacks with a working stroke of 3000mm.
③. Maximum operating pressure at each control point: 63MPa; maximum flow rate: 6.2L/min.
④. Each control point is equipped with a displacement detection sensor with an accuracy of ±0.01mm.
⑤. Each control point is equipped with a pressure sensor with an accuracy of ±0.5%.
⑥. Synchronous jacking control accuracy: ≤±1mm (between each control point).
⑦. The system features dual closed-loop control of displacement and pressure, and has built-in four-point force balancing control.
⑧. Operating ambient temperature: -40°C to +65°C, IP65 protection level.
⑨. Cooling system: The system has a temperature sensor and air cooler system. The air cooler automatically starts and stops based on the system temperature feedback from the temperature sensor, automatically cooling the system.
⑩. Fuel tank capacity: 1500L; Net weight: 2000Kg (excluding hydraulic oil).
Equipment description and technical parameters
- PLC six-point synchronous jacking hydraulic control system:
- Power Supply: AC380V/50Hz;
- Total Power Approx. 45kW;
- Maximum Operating Pressure: 63MPa;
- Number of Control Points: 6;
- Maximum Flow Rate: 6 x 6.2L/min;
- Control Method: Variable Frequency Speed Control (pressure and displacement dual closed-loop control);
- Synchronous Push Control Accuracy: ≤±1mm (between each control point);
- Control Principle: In this hydraulic system, the hydraulic pump station utilizes a variable frequency speed control motor to control the oil pump. By adjusting the power supply frequency, the motor speed is varied to achieve continuously adjustable oil pump flow. Combined with appropriate electronic control and detection feedback systems, pressure and displacement closed-loop control is implemented to precisely control the synchronization of the lifting and lowering jacks at each point and load balancing during the weighing process.
- Hydraulic Principle: The hydraulic pump station utilizes a valve-controlled plunger pump. A balanced load-sharing valve is installed on the oil cylinder to reliably maintain oil flow control during both raising and lowering of the jack. This mitigates the impact of hydraulic shock on synchronization accuracy during the jack’s lifting and lowering switching. The balanced load-sharing valve also provides a leak-proof lock on the jack, preventing it from sliding freely in the event of an unexpected power outage, ensuring the load it supports remains uncontrolled. When multiple jacks are collectively lifting a single load, the balanced load-sharing valve also provides overload protection, effectively protecting the jacks and loads. The system incorporates pressure and displacement sensors. As the jacks move, the pressure sensor accurately measures the load on them in real time. The displacement sensor measures the jack’s real-time displacement, thereby determining the lifting height of the structure.
- Electrical Principle: This electrical control system utilizes a SIEMENS PLC. Pressure sensors and displacement sensors on each cylinder transmit load and displacement signals to a programmable controller.The electrical control system issues lifting commands via buttons. The PLC receives these commands, driving the variable frequency drive unit (VFD) to output pressurized oil to move the corresponding jacks.Based on the detected pressure and displacement signals, the PLC continuously corrects motion errors to maintain synchronized and balanced loads on each jack. The hydraulic pump station system includes a large, touch-screen industrial computer for real-time monitoring of the lifting process and setting of lifting parameters. This system not only meets the requirements for local synchronous lifting control but also allows for connection to an external master control system for online centralized control.
- Pull-wire displacement sensor device
- Pull-wire connection and 90° mounting protection frame for easy on-site installation and protection;
- 2500mm travel range and 0.01mm high detection accuracy;
- Output RS-422 high-stability frequency-divided interface signal with strong anti-interference capabilities and a transmission distance of up to 200m;