الوصف

At present, the diamond table surfaces of PDC drill cutter are plane, global and arc face. When these PDC drill cutters are made into bit, drilling speed of bit will be high because the point of application of cutters are small at the earlier period of well drilling. When the working part of the cutters are worn from plane, global or arc face into plane, the contact surface between cutters and rocks are enlarged, and it appears as that the bit is more and more blunt and the drilling speed of bit is more and more low. 　　According to the above problems of the existing PDC, we have developed the external row tooth PDC which can improve rock breaking efficiency and increase the drilling speed of bit. There are curved surface teeth structure such as trapezoid tooth, sinusoid tooth and triangle tooth on the end surface of diamond layer for selection. The groove direction of curved surface teeth structure points at rock face, the curved surface teeth structure on the diamond layer end surface becomes the working part in rock drilling work, and a row of “teeth” of curved surface teeth structure becomes the cutting edge, and this effect will be remained until the whole cutters are disabled. To the grinding hard stratum, it may obviously improve the rock breaking efficiency of cutters, and increase the drilling speed of bit.