SU1227369A1 - Twist drill - Google Patents

Abstract

A twist drill with a sharpened tip, formed by a cutting, auxiliary cutting edge and two side edges, the auxiliary cutting edge adjoining the side face with an offset from the drill axis, characterized in that, in order to increase productivity, the cutting, auxiliary cutting edge and two lateral edges faces are located at one angle relative to the drill axis. (L (Puz.j to to CO 05 CO

Description

The invention relates to cutting tools for drilling holes on metalworking machines with a diameter of 0.3-80 mm.

The purpose of the invention is to improve the performance and cutting properties of the drill when drilling and plunging by reducing axial forces during drilling and balancing cutting forces, as the drill centers and drills along the marking without centering and drilling, and the same angles of sharpening the cutting, auxiliary cutting edges and two side edges faces relative to the drill axis eliminate the breakdown of the hole and axial cutting resistance.

FIG. 1 shows the cutting part of the drill; in fig. 2 - cutting part of the drill, plan view; in fig. 3 is a view A of FIG. 2; in fig. 4 - main, auxiliary cutting crotches.

The main 1 and auxiliary 2 cutting edges are adjacent to the ribbons 3 and 4 and pass through the axis of the drill. The spiral groove profile from the main cutting edge is described along R 0.2-0.3d and is adjacent to the main cutting edge, its edge 1 but the drill axis. The profile, the second spiral groove is adjacent to the auxiliary cutting edge 2 and is shifted from the drill axis by 0.1-0.2d

0

five

0

in order to create a lateral face 5 for balancing during the drilling of forces and creating sharpened points.

The cutting edge 1 and the side face 5 form an angle in the plan 2U 120 °. The side faces 5 and 6 form, at sharpening, rear angles of 5 ° and converge to the center with the cutting edges i and 2 at one point. Rear sharpening angles with a point of sharpening depart from cutting edges along inclined planes, or in a spiral, and make an angle of 35 °, chosen experimentally.

When rotating, the drill bit (or the material being processed) touching the material being processed faces 5 and b begin to roll out the metal, significantly reducing axial loads, allowing the cutting edges to enter cutting quite easily.

The cutting part automatically aligns the drill axis with the drilling point in the absence of vibrations and interruptions outside the drilling point, since instead of a jumper in the center of the drill there is a pointed drill. After entry into the material of the cutting part of the cone of the drill, the ribbons provide a slip along the walls of the hole.

The reduction of axial forces during cutting increases the reliability and durability of the proposed drill.

QD1d

0; - Q, 2d

R 0,2-0,3d

ig. 2

Back A

Fiyo.Z

Compiled by N. Kiri.

Editor E. KopchaTehred I. VeresKorrektor L. Patay

Order 1991 / 13Tiral 1001Subscription

VNIIPI USSR State Committee

inventions and discoveries

113035, Moscow, 4/5, Raushsk nab.

Branch PPP "Patent, Uzhgorod, st. Project, 4

1rigL

Claims (1)

SPIRAL DRILL SEMAGIN A spiral drill with a point of sharpening, formed by a cutting, auxiliary cutting edges and two side faces, with the auxiliary cutting edge adjacent to the side face with an offset relative to the axis of the drill, characterized in that, in order to increase productivity, the cutting, auxiliary cutting edges and two side faces are located at the same angle relative to the axis of the drill.