Pile Hammer Gas-liquid Joint Drive System Structural Design Of Key Components And Dynamic Process

Hydraulic pile hammer was a kind of the construction equipment, which was widely used in architecture and dock to drive prefabricated pile into ground. Compared with conventional hammers, it has a lot of advantages, such as lower noise, no exhaust gas, less vibration, high piling energy and better dynamics characteristics. At the present time, the hydraulic pile hammer of home and abroad all is distance feedback control mode. Namely after the cylinder piston raises to upper bound, the proximity switch spreads the electrical signal to the Solenoid hydraulic conversion valve and makes the valve conversing, then it causes the cavity and the oil return pipe connection, and the hammer head turns into stroke. The distance feedback working principles of the hydraulic pile hammer determines its technical propertie: the piling energy of the hydraulic pile hammer cannot be adjusted independently and steplessly. So, it is important to research a new-style Hydraulic pile hammer which can adjust the strike energy steplessly.Firstly, this paper based on the analysis of the hydraulic pile hammer in respect of design theory and methods at home and abroad in existence, breaks through the traditional distance feedback control principles and introduces an innovative type of Hydro-pneumatic pile hammer with pressure feedback principles. Through analyzing the working principle and structural characteristic, the pressure feedback hydraulic system has been researched.Secondly, after analyzing the reason of the pile snapped off or detached by strike, researching on the solving projects and choosing the reasonable cylinder buffer structure project. Then optimizing design and simulation research have been done on the cylinder buffer structure, and the computer simulation research proves the feasibility of the structure.Thirdly, in order to adapt the pressure feedback principles, after analyzing the structure and principle of the new control valve, the optimization design has been done, and the system simulation mode of the new hydraulic pile hammer has been established. Then systematically and deeply studied the influence caused by the parameters of new hydraulic pile hammer on the performance of hydraulic pile hammer. Through the simulation research on normal and abnormal working process we know this system can realize using pressure feedback principle to adjust the strike energy steplessly.Lastly, the experiments on the ZCY70 type hydraulic pile hammer made in Hunan Changhe Machinery Co., Ltd show that the results tallied with the simulation research. The new-style hydraulic pile hammer achieved the anticipative effect and demands prove the correctness of theory research. As a result of many innovations on working principles, mechanism, control method, the new hydraulic pile hammer have better working properties.