How to adjust the extension and retraction of the gantry crane arm?

Today, Shandong bridge crane manufacturer will share with you how to adjust the extension and retraction of the gantry crane boom?

Crane arm slewing safety device: When an unexpected accident occurs and the high-pressure hose or oil pipe in the crane arm slewing oil cylinder circuit bursts or is cut off (cut open; cut off), the balance valve in the hydraulic circuit will work to lock the working oil from the lower chamber of the oil cylinder, preventing the crane arm from descending and ensuring the safety of the operation.

Boom extension and retraction (a metaphor for flexibility within certain limits) safety device: When an unexpected accident occurs and the high-pressure hose or oil pipe in the boom extension cylinder circuit bursts or cuts off, the balance valve in the hydraulic circuit will take effect, locking the working oil from the lower chamber of the cylinder, allowing the crane to retract on its own, thereby ensuring the safety of the operation.

The extension and retraction of the crane arm is based on the principle of hydraulic rods, and the specific principle is as follows:

The operation of hydraulic rods mainly relies on oil pressure, clearance between the tappet body and the seat hole, clearance between the valve stem and the tappet, and check ball valves inside the tappet. When the hydraulic tappet first starts working, due to the lack of oil pressure in the chamber, the tappet plunger is at the bottom, and the gap between the tappet and the valve is large, resulting in short-term abnormal noise from the valve. With the operation of the engine, under the action of oil pressure, the plunger chamber in the tappet is filled with oil, the plunger descends, the effective working length of the tappet increases, and the valve clearance decreases. Due to the small force generated by the plunger inside the tappet, it cannot produce the force to compress the valve spring. Therefore, when the gap between the tappet and the valve reaches a very small value, the tappet will no longer move. At the same time, due to the action of the check ball valve inside the plunger, the oil pressure in the plunger chamber of the plunger cannot be quickly discharged, causing the plunger to remain in place and maintain its original length to form rigidity, thereby pushing the valve open. As the engine runs, the valve clearance remains at a certain level.