| 摘要 |
mining industry. SUBSTANCE: invention is used for drilling of boreholes with face flushing with mud solution or water or with blowing of face through with air or gas. Hard-alloy rock-breaking cutting bit is composed of cylindrical tail part and working head coming in the form of mating of convex curvilinear surface and cone. Conicity angle lies within interval 25≅ alpha <27 degrees and is found by formula alpha = atc tgD/2(H3-H2), degrees, where D is diameter of tail part of cutting bit, mm; H3 is height from base of cutting bit to crossing of generators of conical part of its head, mm; H2 is height of tail part of cutting bit, mm. Usage of drill bits with hard-alloy rock-breaking cutting bits with optimal geometrical parameters of head of cutting bit considerably improves indices of their work ( resistance, driving and mechanical velocity of drilling. EFFECT: improved indices of employment of cutting bits. 1 cl, 1 dwg
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