Drilling System Drill Rod Joint Energy Transfer Characteristics Of Study

On the basis of theory of the percussive drilling in this paper, first of all, it has established the mechanical model of the rock drilling machine using the relevant theories of wave mechanics and so on, and derived the wave kinetic equations of the hydraulic rock drilling system. And then, it presents the penetration and efficiency of the impact systems and analyses the matching relationships under dynamic condition between the impact systems and working media systematically. Putting forward a drill rod structure with the force adapted to the drill rod, based on the analysis of impact of the dill rod structure of its anti-fatigue life, which adopts a structure of screw-pair jointing, load-bearing cylinder and thin-wall tube. The characteristic of proposed rod is high energy transfer efficiency and good anti-fatigue life, and thus opens up a new way for the development of China's high efficiency long life rod.Secondly, Research on the stress wave transmission characteristics of the rod joint is also included in this paper. It has advanced Lundberg's work of rigid model. Giving synthetical consideration to joint's elasticity, rigidness, and damping etc., we have established the rod SDM model, and given more precise and overall description of rod joint's dynamic characteristic.The shape of the stress wave with maximum energy transmission efficiency is analyzed under these circumstances that duration of the incident wave and the characteristic resistances are given. Then the energy transmission efficiency of the optimum incident wave is compared with that obtained from a rectangular incident wave which is usually used. It is seen that their differences are very small.Finally, the experimental results of stress wave transmission through the joints have been studied, which strongly proves that the theoretical studies are correct.Furthermore, the research results of this paper not only can provide some of the theoretical and experimental basis for the design of percussive drilling system and drill tools, but also can accelerate the development of mining industry and improve the work efficiency.