PERCUSSION DRILLING TOOL WITH INCREASED IMPACT ENERGY

摘要

A hammer drill bit is intended for drilling wells with increased impact energy. The bit has a body that consists of a shank and a head with projecting main tungsten carbide inserts fixed at its end. At periphery additional inserts with negative angle of working surface are placed. The main and additional peripheral inserts and the inserts on the smaller in diameter adjoining ring are arranged in height in radial direction in such way that the cylindrical surface of the additional inserts and the cutter edges thereof formed by cylindrical surface and the two ends go out with respect to the head of the bit to the level of working surfaces of the main inserts. The working surfaces of the additional inserts can be arranged as a prism, and the main inserts have working surfaces as a hemi-sphere, an ellipse or a prism. The invention promotes increase of stability of drilling tool and increase of drilling efficiency.