The Optimization Of Rotary Drilling Rig’s Working Mechanism And Its Mechanical Analysis

The drilling rig is quite popular in the construction of road, bridge and railway in the past ten years for its convenient and Environment Friendly. The requirement of rig is harder and harder for the demand of construction is much more difficult than before. Today, most of the pile needs to be filling in the rock, so the mechanism of the pile shall be stronger and more stable than before.In this thesis, First, analysis the efficiency of drilling the rock from theory and practical construction, to get the precise requirement in practical drilling. Second, build the mechanics model of the drilling rig to get the force in parallelogram. Third, based on the constraint of force and dimension, build optimization model, and solve the model from genetic algorithm to get the optimal dimension of the parallelogram. Get the root cause of breaking main shaft in practical drilling. The main abstract as below:(1) Analyze the process of drilling rock by analogical. Build the rock drilling model from penetration(drilling depth per revolution), solve the model to get the requirement of torque and pull force of the drilling rig. The model is proved right after comparing with practical drilling parameter.(2) Do mechanical analysis of the drilling rig from the input of last item to get the critical working condition. Get the root cause of breaking main shaft from the analysis of the two critical operation modes.(3) Build the optimization model based on the input requirement below:The assembly dimension and stroke of hydraulic cylinder is shortest.The angle of the cylinder is smallest based on the horizontal plane.The dimension of the drilling machine is smallest.The horizontal and vertical stroke of the parallelogram is largest. Based on the model, get the constraint function; transfer the multi-objective optimization to single-objective optimization by the weight coefficient method in multi-objective optimization.(4) Solve the model function based on genetic algorithm, then get the solution in different weight coefficient. The solution is similar with the practical design, which proves the model is right.(5) Redesign the parallelogram parts based on the result above; get the stress from finite element analysis, find the critical area of these parts, optimal the dimension of the parts to get the optimal design model.