As the core component of the hydraulic system, hydraulic cylinders are widely used to lift, move and position mechanical equipment. In many application scenarios, such as aerial work platforms, bridge jacking and mechanical arm operation, multiple hydraulic cylinders need to operate simultaneously. However, if the hydraulic cylinders move out of sync, it will not only reduce the operating efficiency of the equipment, but also cause equipment damage and safety accidents. This is why synchronous control of hydraulic cylinders is so important.
What are the three benefits of synchronised hydraulic cylinder operation?
Improved stability of equipment operation
In lifting equipment, such as aerial work platforms or bridge jacks, synchronous movement of hydraulic cylinders can ensure platform stability and prevent damage or injury caused by equipment tipping.
Improving the efficiency of equipment operation
The operation of industrial machinery requires multiple hydraulic cylinders to work together to perform complex movements. Controlling synchronous hydraulic cylinders can reduce errors and unnecessary adjustment time during operation, speeding up equipment operation efficiency and improving production.
Ensure equipment safety
When equipment is running, if hydraulic cylinders are out of sync, it can cause uneven force on the structure, increasing the risk of equipment damage. Controlling synchronous hydraulic cylinders can effectively distribute the load and extend the life of the equipment.
Four problems that can occur when synchronising hydraulic cylinders
Load difference problem
Different hydraulic cylinders can be subjected to different pressures. For example, in lifting equipment, uneven pressure distribution on the platform can result in different speeds of movement of hydraulic cylinders.
Load differences will affect the pressure balance and flow distribution of the system, increasing the difficulty of synchronised control.
Flow distribution problem
The flow in the hydraulic system must be accurately distributed to each hydraulic cylinder. Even a small flow difference will add up to a large displacement error.
Fluid leakage and uneven pipe resistance will further increase the complexity of flow distribution.
Problem of mechanical structure differences
The tolerance of the hydraulic cylinder, the deviation of the installation position and the wear during use may cause differences in the mechanical characteristics and affect the uniformity of the hydraulic cylinder movement.
Environmental factors problem
Changes in the ambient temperature will cause changes in the viscosity of the hydraulic oil, which will affect the flow and pressure of the system.
Vibration and shock in the external environment can also affect the synchronisation of hydraulic cylinders.
Three principles for synchronised operation of hydraulic cylinders
Flow balance principle
The speed of movement of hydraulic cylinders depends on the flow rate. It is necessary to ensure that each hydraulic cylinder receives the same amount of hydraulic oil to achieve synchronisation of hydraulic cylinders.
Flow dividers or synchronising valves are components used to achieve equal distribution of the oil flow.
Pressure balance principle
In the case of large load differences, pressure equalisation is an important factor in ensuring synchronised movement of hydraulic cylinders. By adjusting the pressure valve, the hydraulic cylinder can maintain the same speed of movement under different loads.
Feedback control principle
By installing displacement or pressure sensors that monitor the position or pressure of the hydraulic cylinder in real time and feeding the data back to the controller, the flow and pressure can be adjusted dynamically.
Closed-loop control is one of the most important technologies for controlling synchronous hydraulic operation.
Four methods for achieving synchronous operation of hydraulic cylinders
Mechanical linkage method
Principle
Multiple hydraulic cylinders are connected by mechanical devices such as connecting rods, gears or chains to force synchronisation.
Advantages
Simple structure and low cost.
Does not require complex hydraulic or electronic control.
Disadvantages
Mechanical devices add weight and complexity to the system.
Synchronisation accuracy may be affected by the accuracy of the mechanical structure and installation errors.
Flow distributor method
Principle
Install a flow distributor or synchroniser valve in the hydraulic system to distribute hydraulic oil evenly to each hydraulic cylinder.
Advantages
High precision control capability, suitable for medium and low precision requirements.
Maintenance of the system is relatively simple.
Disadvantages
High precision requirements for flow distributors.
Wear or leakage problems may occur over time.
Proportional or servo valve method
Principle
Accurate control of oil flow through proportional or servo valves, combined with closed-loop control systems to achieve high-precision synchronisation.
Advantages
High-precision synchronisation capability, suitable for scenes with large load differences.
Parameters can be dynamically adjusted to adapt to complex working conditions.
Disadvantages
The cost of the system is high.
Control system design and debugging are relatively complex.
Electronic control method
Principle
Combine displacement sensor, pressure sensor and PLC controller to control the action of the cylinder by program.
Advantages
High degree of intelligence, can achieve a high degree of automation.
Can monitor and adjust in real time, adapt to a variety of complex working conditions.
Disadvantages
High initial installation and troubleshooting costs.
High demands on the reliability and interference resistance of the electronic components.
Improving the synchronous motion system of hydraulic cylinders through position sensing
The role of displacement sensors
Monitor the displacement of hydraulic cylinders in real time and accurately measure the distance travelled.
Provide displacement data to the controller to achieve closed loop control.
Combination of displacement sensors and controllers
The control system dynamically adjusts the flow and pressure of the hydraulic oil based on the displacement data provided by the sensor.
This method is suitable for scenarios where extremely high synchronisation accuracy is required, such as bridge jacking and aerospace equipment.
Four benefits of using intelligent sensors to synchronise the movement of hydraulic cylinders
Improve synchronisation accuracy
Smart sensors can provide highly accurate displacement and pressure data, greatly reducing synchronisation errors.
Reduce manual intervention
Intelligent control systems can automatically adjust parameters without frequent manual intervention.
Improve equipment safety
It can monitor equipment status in real time, detect anomalies and provide timely alarms, reducing the risk of accidents.
Adapt to complex operating conditions
Intelligent sensors combined with algorithms can adapt to complex and changing working conditions, improving equipment stability and safety.
Application Cases
Hydraulic cylinder synchronisation control of aerial work platform
The flow distributor and displacement sensor are combined to achieve smooth lifting of the platform.
Applications include construction, lift equipment, etc.
Bridge lifting system
High-precision synchronisation of multiple cylinders is achieved using servo valves and closed-loop control technology.
Effectively prevents uneven force on bridge structures and ensures construction safety.
Robot operation
In industrial robots, precise co-operation of hydraulic cylinders is achieved through electronic control methods and intelligent sensors.
Production efficiency and product quality are improved.
Synchronous operation of hydraulic cylinders plays an important role in the operation of industrial equipment. Depending on the specific application requirements, various methods such as mechanical linkage, flow distributor, proportional valve or electronic control can be selected. With the development of intelligent sensor and control technology, the synchronisation accuracy and adaptability of hydraulic cylinders will be further improved.
As a professional manufacturer in the field of hydraulic technology, EASTAI can provide high quality hydraulic cylinders and synchronous control solutions to help customers achieve more efficient and safer equipment operation. For more technical information or customised solutions, please contact us!
