SU1662770A1 - Method for machining non-round cylindrical surfaces - Google Patents

Abstract

The invention relates to mechanical engineering and can be used in the treatment of, for example, non-circular shafts. The invention makes it possible to increase the shaping accuracy due to the relative movement of the cutting edges of the mill along a straight line forming the machined surface. The axis of rotation of the cutter, which is disposed eccentrically of its geometric axis, set at an angle to a plane perpendicular to the axis of rotation of the workpiece, which is determined by the formula φ = ARCSIND:, where D - mean diameter of the treated surface (D ^K.)

K - the number of protrusions of the surface profile

D is the diameter of the cutter. The milling cutter and the workpiece are reported to have a consistent rotation in opposite directions. 3 il.

Description

The invention relates to mechanical engineering and can be used in the treatment of, for example, non-circular shafts.

The purpose of the invention is to improve the shaping accuracy due to the relative movement of the cutting edges of the mill along the straight line forming surface.

FIG. 1 shows a scheme for carrying out the method; in fig. 2 - the same plan view; in fig. 3 is a diagram of the formation of a profile of the treated surface.

The processing of the workpiece 1 is carried out by a cylindrical mill 2, a geometrical axis 3, the blanks are installed with the eccentricity I relativity 4 of the rotation of the mill. The latter is set at an angle p to the plane perpendicular to the axis of rotation of the workpiece 1, which is carried out around its geometrical axis 5. The value of eccentricity I is set half the size h of the height of the profile projections relative to the circle inscribed in it.

In the course of processing the frezé 2, rotation with the frequency Pf around the axis 4 is reported, and the workpiece 1 - rotation with the frequency P3 around the axis 5, while the ratio of frequencies PF / P3 is set equal to the number K of profile projections. At the same time, the milling cutter reports on the workpiece displacement (feed) S in the longitudinal direction

As a result, the point C of the cutting edge, which is involved in the formation of a given profile of a non-circular surface, makes two motions relative to the point of contact with this surface, one with a velocity of VOLO n3 and another with a velocity of Pf, where D is the average diameter of the non-circular profile d is the diameter cutters.

The maximum accuracy of the formation of a non-circular profile is achieved when the direction of the velocity V is oriented, resulting in a resultant movement along a rectilinear non-circular surface. In this case, the profile of a non-circular surface is formed as an envelope

WITH

WITH

oh oh

hO XI S | ABOUT

straight line cutting edges of the teeth of the cutter (Fig. 2). To provide the indicated speed of the resultant movement, the rotational movements of the workpiece and the cutter are set in opposite directions, and the axis of rotation of the cutter is set to a plane perpendicular to the axis of rotation of the workpiece at an angle (p, the value of which is determined by the formula

 v ° p- arcsln -rr

OR (p arCSin T7-T;

Since the profile of the non-circular surface is formed straight, the height of the faceting is

-Ј

where I is the distance between adjacent points of contact of the instrument with the formed profile;

d is the radius of curvature of the profile between these points.

Approximately it is possible to accept r D / Z, where D is the average diameter of a non-circular profile.

The profile section between the vertices of its adjacent protrusions is formed in one revolution of the cutter, i.e. Z is straight where Z is the number of teeth, then I is jrD / KZ. Therefore, you have 1 profile cut

A - () 20.

When processed by a known method, the profile is formed by Z circles, the diameter of which is approximately equal to the diameter of the cutter.

Therefore, the cutting height with a known method of processing

  (4b + u.

0

five

0

five

0

five

0

which is much more than the proposed.

The average external speed of the teeth of the cutter V V / cos prp.e V is the cutting speed. Since V l d, the frequency of rotation of the mill is equal to

 . The frequency of rotation of the workpiece is set to K times smaller. The values of the cutting speed V and feed rate S are determined according to the standards of cutting conditions or experimentally.

Claims (1)

Claims The method of processing non-circular cylindrical surfaces with a cylindrical cutter, which rotates around an axis eccentrically relative to its geometrical axis, and moves relative to the workpiece, which is reported rotation, consistent with the rotation of the cutter, characterized in that, in order to improve the shaping accuracy due to relative movement cutter edges along a straight line forming the machined surface, the mill and the workpiece rotate in opposite directions, and the axis Esa is placed at an angle to the plane perpendicular to the axis of rotation of the workpiece, the value of which is determined by the formula . (p arcsin -p. where D is the average diameter of the treated PB surface; K - the number of protrusions of the profile of this surface; d is the diameter of the cutter. Phage / Hl 2 Fig.Z