Nitrogen Mathematical Simulation Of The Dynamic Characteristics Of The Hydraulic Hammer And A New Method Of Performance Testing

Hydraulic impact hammer is a kind of construction equipment , which uses the liquid with high pressure as the driving medium and changes the hydraulic power into impacting power to accomplish the breaking function. As a kind of hydraulic impact hammer with special working mechanism, relatively simple structure and excellent performance, Nitrogen-Inflating hydraulic impact hammer has been produced in series in overseas. But there is almost no similar products and research which can compare with them in our country.Based on relatively detailed analysis of working mechanism of Nitrogen-Inflating hydraulic impact hammer, using Power Bond Graph method which is an advanced modeling tool and State-space matrix analyzing method, this paper established the Power Bond Graph model and mathematic model in State-space method of the researching object. According to the computer simulation, some basic parameters, such as liquid damping, liquid condense, inertia effect etc, have been analyzed, and the changing rule of the impacting performance have been researched with the changes of the main structural parameters and working parameters. At the same time, a key problem ?piston's and control valve's movement matching was analyzed as a special subject, and the analytical formulas of Lv} and Svpx wasobtained. Secondly, according to the structural characteristic and its special working mechanism of the researching object, a new impacting performance testing method ?Air-Pressure indirect testing method was brought into effect successfully. While implementing this new testing method, digital filter was used for the first time and good results were obtained. In addition, some important processes from designing testing system to processing of data about this new testing method have been given in detail. The testing results are consistent with the results of theoretical analyzing and simulation.The research results above will play an important instructing role in theory to the design and production of the Nitrogen-Inflating hydraulic impact hammers. Theprofound researches of its internal conducting rules provide significant technical foundation for the technique improving and product upgrading. Air-Pressure indirect testing method provide a simple, reliable and applicable testing mean for the testing of hydraulic impact hammers. This method not only is with important applicable value, but also with useful extending value.