UA14830U - Method of sharpening the drill with curvilinear cutting edges - Google Patents

Abstract

The method of sharpening the drill with curvilinear cutting edges includes sharpening by shaped grinding wheel mounted on the axis perpendicularly to the direction of reciprocating motions of the drill. In this case, for simplification of kinematical pattern of working the sharpening is performed by a shaped grinding wheel, profile of which is outlined on the circular arc, which rotates around a fixed axis, and drill, axis of which is perpendicular to the axis of grinding wheel and performs reciprocating motions at a speed of , perpendicular to the axes of drill and grinding wheel.

Description

Description of the invention

The proposed useful model belongs to the field of mechanical engineering, in particular, to tool 2 production, and can be used in the process of manufacturing and operating spiral drills.

A known method of sharpening drills in planes with two shaped grinding wheels installed with a gap on one axis inclined relative to the reciprocating movements of the drill | see author's certificate of the USSR Mo3330141.

The disadvantage of this method is the unfavorable geometry of the transverse cutting edge, which creates large 70 negative front and back angles.

Known methods of sharpening drills with curved cutting edges are relatively complex and require special devices and machines.

The basis of a useful model is the task of improving the performance of a spiral drill by creating a sharp transverse edge and positive rear angles during sharpening (Fig. 1, 2). 12 The method of sharpening a drill is based on the use of a shaped grinding wheel, the profile of which has an arc of a circle, radius g, and its axis is located perpendicular to the axis of the drill, which performs reciprocating movements at a speed of 57 . During the rotation of the shaped circle, a cylindrical surface is formed (Fig. 1, c), which forms the back surfaces of the drill. At the same time, in order to obtain positive rear 2o Angles, the position of the drill relative to the cutting edges and the position of the wheels are determined by the ratio: i to tor-vipo

SI - soy de vu - instrumental rear corner; and about ; my diameter with a is the diameter of the core of the drill;

E- radius of the drill; ts- angle at the tip of the drill; o 30, What is the back corner on the periphery of the drill; me) p- angle characterizing the position of the studied point on the cutting edge; со "- the radius of the limit circle of the grinding wheel. «

Angle p (Fig. 2) at point A, with known values 4 and c); determined by the ratio: 35 Yud-Yuf-sov6)|. t

The position of point A relative to the face of the circle is determined by the ratio:

Id-g.sov r.

Size c, which determines the position of the drill axis relative to the grinding wheel, is equal to: "sUId-K.osov (tsbu)-g.sovrD-K.sov (ts8 |). w-v c The essence of the useful model is explained by the drawing (see Fig. 1), which shows the scheme of sharpening the drill by the proposed method and on which the positions are marked: c 1 - drill; 2 - drill axis;

Z - the axis of the grinding wheel; - 4 - grinding wheel.

The position of the axis of the grinding wheel, corresponding to the speed 5, , is characterized by a right angle of 90 e. The position of the drill relative to the grinding wheel is determined based on the geometric parameters of the cutting (ee) part on the periphery of the drill at point A of the cutting edge. Thus, in three dimensions, the position of the drill bit 50 relative to the grinding wheel is determined by the parameters Id, c and the angle 8).

To remove the allowance on the cutting part of the surface of the drill, it is periodically brought closer to the grinding m) wheel with feed Z (Fig. 1, b) along the axis. However, at the moment of formation of the rear surface, this movement is disabled.

The position of the drill, that is, the angle 6), is chosen in such a way as to obtain, as a result of sharpening 22, the required value of the back angle о on the periphery of the drill, when it is measured in a cylindrical bend, with the concentric axis of the drill. Angle 8) is determined by the formula: 2 to". der - vipr.- sor, in The surface in the central zone of the drill is created by the cylindrical surface of the grinding wheel, radius r, which is ensured by the appropriate selection of values I, c and 6); - between the grinding wheel and the drill.

As a result, the back surface of the drill is formed in the form of a shaped cylindrical surface, the profile of which coincides with the profile of the grinding wheel.

In order to obtain an independent value of the angle of inclination of the transverse edge, each tooth of the drill is sharpened b5 on two cylindrical surfaces. The position of the drill for this every time when sharpening the rear surface is determined by the installation angle 6).

Claims (1)

The formula of the invention 5. m. - - A method of sharpening a drill with curved cutting edges, which includes sharpening with a shaped grinding wheel installed on an axis perpendicular to the direction of reciprocating movements of the drill, which differs in that, to simplify the kinematic scheme of processing, sharpening is carried out with a shaped grinding wheel, the profile of which is outlined along an arc a wheel that rotates around a stationary 70 axis, and a drill whose axis is perpendicular to the axis of the grinding wheel performs reciprocating movements at a speed of 5; , perpendicular to the axes of the drill and the grinding wheel, while the position of the drill is located at an angle 8), which is measured in the projection on the plane perpendicular to the axis of the drill, and the value of which is calculated according to the accepted geometry of the cutting part on the periphery of the drill. that 2 "c) (ze) (ee) " e - and? - sh" (ee) (95) (42) 60 b5