SU715238A1 - Drill - Google Patents

Description

(54) DRILL

The invention relates to the field of metalworking and can be used for drilling various materials. Constructions of spiral drills with a curved shape of the cutting edges 1 are known. However, the parameters of these curves are not related to the nature of the change in the area of the metal being cut with increasing drill radius. A disadvantage of the known drill is the unequal wear resistance along the length of the cutting edge from the axis of rotation and to the periphery, which limits the service life of the drill and the efficiency of its use. The aim of the invention is to increase the wear resistance of the drill. This goal is achieved by cutting crms in a plane perpendicular to the axis of rotation, performed in a spiral shape, the length of any portion of which to the corresponding area described by it during rotation is constant and is polarized in polar coordinates by the equation of the form / 47ty-) ci -korctjj-f / 4П: 2-р -к2 КЧ, (О where 05 is the current radius of the number; R is the radius of the drill; is the coefficient nponopiwonam aost, which determines the rate of development of the curve; dimensionless coefficient (}) and the gradient; H current polar angle. In Fig. 1 shows the proposed Fig. 2 is a view A of Fig. 1 Drill 1 has a cutting edge 2, the shape of which, and hence the shape of the concave front face of the drill, is executed as part of a special spiral-type curve, with the current polar radius p having the length increases by an amount proportional to wolf

Claims (1)

Claim Drill with curved cutting edges, characterized in that, in order to increase its wear resistance, the cutting edges in the plane perpendicular to the axis of rotation are made in the form of a spiral curve, the ratio of the length of any portion of which to the value of the corresponding area described by it during rotation is a constant and is expressed in polar coordinates by an equation of the form V4 ^ ² p ² 'K ² · - Kcrctpf -y / 4-1 ^ ^2, p ¹ -K ² = ΚΨ, where 0 * £><Κ is the current radius of the curve; R. is the radius of the drill; K = 6tR - coefficient proporional. bones, which determines the rate of development of the curve; O <a <mc is a dimensionless coefficient; H ’is the current polar angle. Source15 information taken into account during the examination 1. Ladin Μ. N. High-performance drill designs and their rational operation, VNII, M., 1960, p. 46, fig. 34. TSNIIIPI Order 9412/9 Branch of PPP Patent, Circulation 1160 Subscription Uzhhorod, st. Project, 4