A Study Of The Port Valve Assignment Hydraulic Down-hole Hammer Vibration And Working Charactristics Experimental Simulations

The Percussive Rotary Drilling is a drilling method of great highefficiency. Great amount of researches have been done since it first cameinto use.Researches have been conducted regarding Percussive Rotary Drillingmethod in order to increase its efficiency and the energy utilization. Muchwork has been done on the theory of rock breaking and its process, energytransfer laws, shock wave propagation and its process. But not much of thework has been focusing on how the hammer vibrates down the hole or whetherthe vibration has any impact on drill bites or other drilling tolls andfurther more, how much impact.On the other hand, the testing technology has attracted much attentionand gained much progress. There have been many methods of testing a resultof a down-hole hammer. Though the methods are many, but a big project itstill is, taking too much work to carry out. While it is commonly believedthat simulation is a method that solves all the problems to reduce costs.There have been some studies and experiments on simulation but none hasreached the application level.This dissertation conducted a literature review first and investigatedthe current status of percussive rotary drilling from perspectives oftechnology, theory, technology on testing and commonly used tools.. analysesthe vibration performances of make-ups of the strings down-hole, employingthe complex coordinates system to establish the differential equation ofmotion, and the Fourier Series to solve the equation. With the combinationof these methods, a vibration model of down-hole strings make-up isestablished, providing theory basis for designing hydraulic hammer to reducedesign costs and to improve design level. This dissertation also builds up a new model using fluid-solid interaction after analyzing the motioncharacteristics of important components. The analyses are based on aparametric modeling system. With the help of this simulation model, timeand cost of the testing are reduced and the efficiency of designing isimproved.This dissertation studied closely on the process of the movement of thehammer and the valve, built up a new model using fluid-solid interactionafter analyzing the motion characteristics of important components. Theanalyses are based on a parametric modeling system. With the help of thissimulation model, time and cost of the testing are reduced and the efficiencyof designing is improved.