EFFECT OF LATERAL PITCH OF A POINT ATTACK BIT ON IMPACT CUT ABILITY ON MORTAR

摘要

The object of this study is to investigate experimentally the influence of longitudinal pitch p_(lon), lateral pitch p_(lat) and cutting depth z of a point attack bit on the cutting torque and on the amount of debris to find the optimum lateral pitch p_(lat). In this study, we carried out several experiments for various combinations of p_(lon), p_(lat) and z. As the result of the research, the empirical relationship to express the amount of debris per unit cutting work Q_w as a function of longitudinal pitch plan, lateral pitch p_(lat) and cutting depth z was established. The optimum lateral pitch, at which the amount of debris per unit cutting work Q_w has a maximum value, is identified at 5.0 cm for a longitudinal pitch p_(lon) of 4.5 cm and cutting depth z of 4.0 cm.