The Simulation And Research On Hydro-pneumatic Driving Uninterrupted Compactor Mechanism

As a widely applicable, high-efficiency and economical compaction method, dynamic compaction is widely used in industrial and civil buildings, mountain-blasting and silt-filling, foreshore reclamation, docks, airports and highways and other infrastructures. With the improvement of compaction requirements and efficiency, dynamic compaction technique develops rapidly, and has turned to uninterrupted dynamic compaction from traditional decoupled hook dynamic compaction.The hammer and hoisting wire rope or pulley group are separated by self-release mechanism in decoupled hook dynamic compaction, while in uninterruped dynamic compaction, the hammer remains in connection with wire rope and quick dropping of the hammer is achieved by hoisting mechanism. At present, the uninterrupted dynamic compactors on the market are actualized by improving the hoisting mechanism braking system or using free-fall winches. The complex structures and the high cost of free-fall winches restrict the wide application of uninterrupted dynamic compaction machine. Therefore, the design of a new type of uninterrupted compaction mechanism for medium or low energy levels dynamic compaction construction, which replaces the traditional decoupled hook mechanism and hoisting mechanism, is great of significance to reduce the machine costs, improve efficiency and promote uninterrupted dynamic compaction technology.In this paper, a new type of hydro-pneumatic driving uninterrupted compactor mechanism is designed. Instead of the traditional hoisting mechanism, a hydro-pneumatic cylinder is used in the mechanism to drive the movable pulley group directly. And it has the advantages of simple structure, high efficiency, low cost of fabrication and simple control and so on.Firstly, the factors influencing the performances of hydro-pneumatic driving uninterrupted compactor mechanism are discussed in the present paper. Then, the main parameters of the mechanism are calculated and the structure of the mechanism is designed. Secondly, the dynamic simulation analysis software ADAMS and the3D solid design software Pro/E are used to establish the model of wire rope-pulley group system and the whole mechanism system. After that, the Simulink module and Simscape module in Matlab are applied to create the model of the pneumatic system and hydraulic system. And then, the co-simulation model of whole machine is created by ADAMS/Controls and signal interaction setting. Then the simulation parameters are set and coordinated simulation is conducted. Finally, according to the simulation results, the impacts of different initial aerated pressures and different gas cylinder volume on the performances of the mechanism are analyzed, the performances of the stepped cylindrical cushioning structure of hydro-pneumatic cylinder are also simulated and analyzed.The results show that, with0.9MPa initial aerated pressure and600L gas cylinder volume, the mechanism meet the requirements that the length of the wire rope released by the rising of the movable pulley group is always longer than the free falling distance of the hammer during the hammer falling. The stepped cylindrical cushioning structure of the hydro-pneumatic cylinder can limite the end of the cushioning speed below0.04m/s, which is only accounted for2.9%of the initial cushioning velocity. So the cushioning effect is obvious.The research contents and the results in this paper provide certain references for the design and analysis of uninterrupted compactor mechanism.