Study And Design Of Pneumatic DTH Hammer With Self-propelled Round Bit

Because of the advantages of high drilling efficiency, good hole quality, no pollution to environment and so on, pneumatic DTH hammer has been widely used in many fields. Such as blasting hole construction, hydrology and water well drilling, engineering geological exploration and so on. But there also exist some problems. For example, disturbance of hole wall and low utilization rate of drill.To solve these problems, this paper designed a pneumatic DTH hammer with selfpropelled round bit. Only need to input high pressure gas, percussion rotary movement of the DTH hammer can be put into practice. Because the hammer is designed with a rotary joint, the percussion rotary movement can be realized while drill rod is not rotate. This design not only reduces the drilling equipment, but also can effectively reduces drill pipe fatigue destruction, hole wall disturbance in the process of drilling.The specific work of this paper is as follows:(1) Study on the working principle of pneumatic impact equipment. Mainly studies structure and working principle of the domestic and foreign typical no valve pneumatic DTH hammer and rock drill. By studying the structure and principle of various pneumatic impact equipment, analyzing its advantages and disadvantages, drawing on its design method. These are important paths of developing idea in conceptual design.(2) Structural design, parameter design and the concrete component design of the pneumatic DTH hammer with self-propelled round bit. On the basis of studying the working principle of pneumatic impact equipment, this paper designs a kind of pneumatic DTH hammer, which can realize the self-rotate of drill bit. According to the design theory and method of pneumatic impact equipment, the design of parameters and the design of specific parts are carried out.(3) Key parts strength checking. This paper, by using the finite element analysis software ANSYS to check strength of the spiral rod, the ratchet wheel and the ratchets.(4) Dynamic simulation of the DTH hammer through ANSYS. In order to study the energy transfer law in the process of impact and verify that under the action of dynamic load, whether the strength of piston design meet the requirements.Use ANSYS/Explicit dynamics to analyze impact dynamics on the process of piston impact drill bit.