SU1574470A1 - Drill - Google Patents

Abstract

The invention relates to the field of engineering, in particular to the design of drills for the formation of holes in building materials by a rotary percussion method, and allows an increase in productivity and quality. This is achieved by the fact that the blades 5 and 6, affecting the building material, perform the work of destruction and provide the condition of extrusion of the drill fines, while the central angle is Ψ = 2ARCSIN [SIN (Θ _cr / 2) / SIN Α], where Θ - the angle between the rear edges of the face cutting blades, α is the angle of grinding of the edge blades. 4 il.

Description

dida

U1

ate 1

4in 1

2

The invention relates to mechanical engineering, in particular to the construction of drills for the formation of holes in building materials by a shock-rotary method.

The purpose of the invention is to increase productivity and quality.

FIG. 1 shows a drill with a single carbide blade; in FIG. 2, view A in FIG. 1, in FIG. 3 shows a section BB in FIG. 1, in FIG. - carbide blade drill, general view

The drill bit consists of a shank 1, a housing 2 with a spiral groove 3 and a head fitted with a carbide insert Sharpened to form symmetrically inclined face cutting blades 5 interconnected by a central blade 6 formed by the back edges of the 7 blades 5, which form the rear angle of grinding at. The plate k is installed in the groove 8 of the head of the casing of the drill and solder solder. Blades 5 form a central angle /,

SKP (f 2arcsin (sin r- / sineO,

de

Ј "

d. the angle of the central blade, which, taking into account the operation of the blade 6, under conditions of impact destruction of the central zone of the face, is selected in the range of 5-50 °. blade sharpening angle 5, equal to 55-65 ° for

thirty

35

hand-held percussion machines.

The drill works as follows. 40 After the drill stops against the machined surface (not shown) of the blade.

0

five

0

five

0

5 and 6, working on the building material, the work of destruction is performed. The total sharpening angle of the blades 5 is typically 80-100 °, which makes it possible to destroy the bottom of the hole by both cutting and hitting.

Making the central angle of the plate (according to the proposed correlation allows to ensure the destruction of the central zone by the blade 6 with an angle of sharpening in the range of 5 to 50 ° optimal for shock loading of the building material and to ensure the conditions of extrusion of the drilling fines from under the blades 5 and 6 to the spiral grooves 3 body 2 drill.

Claims (1)

Invention Formula A drill bit comprising a body with a shank and a head having at least one carbide plate with a sharpening angle between the front and rear edges of the end blades interconnected by a central blade positioned perpendicular to the axis of the drill, characterized in that quality, the central angle formed by the end blades is determined by the ratio Y 2arcsin sin (9K / 2) / sin t / J, where wcr is the angle between the posterior faces of the face cutting blades; “- angle of sharpening of end blades. 1 FIG 4