Designing The Mechanical Structure And Hydraulic System Of Hydraulic Piling Hammer

New requirements have been put forward for the development of the pile foundationbecause of constructing the facilities such as large port, deepwater wharfs, and sea platformand so on, and working underwater, for example, mining source of energy in deep sea. As akey machinery of piling, hydraulic hammer have powerful energy, high efficiency,non-pollution and other advantages, so it plays an important role in the development of largepile machinery and economic construction. At present, domestic large underwater hydraulicpiling hammer all depend on import from foreign countries, and the key technology is stillat a primary stage, so it is very importing to study the hydraulic piling hammer.In this paper, in order to prevent ram to rebound and to avoid direct hit between ramand pile, reduce vibration and impact and avoid the damage of hammer and pile, the bufferand anti-vibration device of hydraulic piling hammer, including shock absorber ring,suspension unit and anvil, were designed. And two connecting devices which are flexiblecollar and flange were designed. Flexible collar not only realized the flexibility of theimpact between ram and pile, but also enabled hammer to blow oblique pile of certain angle.And flange connection realized the purpose of hydraulic piling hammer hitting differentdiameter pile. To realize the function of underwater operation, decrease the resistance of theham during pile hammer works, the gas seal structure was designed.In order to increase the blow energy and improve the working efficiency，double actionprinciple are used in the hydraulic system. Basing on the double action principle, mainparameters of accumulator, hydraulic pump and valves have been calculated, and models ofthe hydraulic components were chose. Hydraulic piling hammer’s three stages of pilingprocess: rising, falling and pressure maintaining were simplified, and the mathematicalmodel of each stage is established. The high pressure accumulator’s curves and the rammovement curves in the rise and down of ram were simulated and analyzed. At last, theimpact theory of hit between pile and ram: the stress wave and ram rebounding wasanalyzed. According to different materials, the hit models between ram and pile weresimplified and the impact force was qualitatively analyzed.In this paper, according to design the virtual prototype’s mechanical structure andhydraulic system of hydraulic piling hammer, not only the problem of great vibrationproduced during ram and pile hitting has been solved, but also hydraulic piling hammer’sapplicable scope was more extensive. Basing on the design and simulation of hydraulicsystem, the characteristics of the ram movement were analyzed. According to the simulationresults, the theoretical analysis was verified to be correct, and it provided important basis for hydraulic piling hammer’s experimental prototype in the next step.