Design Of Large Diameter Percussive And Rotating Combined Multi-dynamics Drilling Tool

With the rapid development of economic construction in our country and the expansion of infrastructure and construction projects, cast-in-place bored pile has been widely used due to its own unique advantages. But it has low drilling efficiency and high drilling cost in complex strata. Therefore, development of a new large caliber construction drilling tool and technology is very important.The article takes "investigation and study, comprehensive analysis, the key mechanism design, field test" as the main method, makes comprehensive study on various drilling tool and technology, on the basis of which a study on large diameter percussive and rotating combined multi-dynamics drilling tool and drilling technology is made. The main research contents and results are as follows:1. Take an analysis and summary of large diameter drilling technology and construction equipment, and introduce a new rock crushing technology of the hydraulic breaker.2. Design the overall scheme and key components of the drilling tool, such as working principle, combination structure, oil distribution mechanism, rotary actuator, drill bit, slag discharge system and hydraulic control system, and make force analysis and calculation of the key components to meet the requirements of strength of materials.3. Take analysis of percussive-rotary rock crushing effect factors, determine drilling parameters, such as impact energy, impact frequency, drilling pressure, rotational speed, torque, flushing liquid rate of return and pump capacity.4. Complete design of large diameter percussive and rotating combined multi-dynamics drilling tool.In this paper the design of combined drilling tool enriches our large diameter drilling equipments, and has certain reference significance for its high drilling efficiency and low cost in complex formation.