How does the balancing pneumatic cylinder work?

Heavy load balance is the balance state when there is heavy load on the balance crane, and no-load balance is the balance state when there is no load on the balance crane. No matter what kind of balance state, the gripper will be in a static state. At this time, it only needs a small external force to lift or lower the weight or the gripper. Using the principle of balance cylinder can improve work efficiency and reduce labor intensity. And the balance cylinder has the advantages of simple structure, less components and low cost, which can be used in harsh working conditions. The core component of the balance cylinder is a large flow, large emissions, high-precision pneumatic precision pressure reducing valve, which is directly related to the positioning accuracy of the weight, the external force required to move the weight, and the speed of moving the weight. The inlet pressure of the two pilot pressure reducing valves is taken from the main pipeline, which is respectively used as the pilot valve for heavy load balance and no-load balance. The two-way pilot gas is connected to the two position three-way directional valve, which is used to switch the heavy load balance and no-load balance. After passing through the directional valve, the pilot gas flows into the pneumatic pressure reducing valve, and the outlet pressure of the pneumatic pressure reducing valve is equal to the corresponding pilot pressure. The gas in the main pipe passes through the cylinder after being reduced by the pneumatic pressure reducing valve. After the SMC cylinder is filled with gas, the piston rises to pull up the weight. When the heavy object is in a static state after being lifted, it means that the heavy load balance is reached. At this time, only a small external force is needed to break the balance, and the heavy object can be easily lifted or lowered. Take pulling down a heavy object to break the balance as an example. When the external force is used to pull down, the piston in the cylinder moves downward. At this time, the pressure in the cylinder rises and exceeds the set pressure (the set pressure is the pressure during balance), and the excess pressure will be discharged from the discharge port of the pneumatic pressure reducing valve.

The result of such a process is that the piston (weight) drops to a certain position and remains stationary, and the pressure in the cylinder returns to the previous equilibrium pressure. On the contrary, lifting a heavy object to break the pressure balance in the cylinder is the same, except that the gas flows in reverse direction (from the cylinder to the exhaust port of the pneumatic pressure reducing valve) and in positive direction (from the pneumatic pressure reducing valve to the cylinder).