削孔機械の主要諸元および操業条件と削孔速度との関係について

抄録

Various drilling or boring machines are developed, modified, and applied in the field of mining and tunneling. However, the principle for design of drill and decision of their technical specifications is not established, and they are based substantially on the experiences in the field operation.
Firstly, the author refers to several test results on the process of bit penetration into the sample rock as well as results of the field test. Then, some fundamental equations between the force and depth of penetration of each bit wedge are given ,taking the effect of rock strength into account, on the basis of theoretical analysis and/or experimental results in the laboratory as well as field. The equation is written in the form of the complete equation in dimension.
Secondly, the author gives several mathematical equations to estimate and control the drilling rate of drill bit, as the function of various operational parameters of drilling machine. The equation of drilling rate includes the proportional constant which is affected by such technical factors as drillability of the rock mass, interference between each bit wedge, effect of flushing fluid, length of drill rod, etc.. These constants could be estimated from results of test drilling and/or field experiences.