SU1310176A1 - Method of abrasion working - Google Patents

Abstract

The invention relates to abrasive machining, in particular to the magneto-abrasive machining of bodies of revolution with external thread: screws, forks, power screws, and propellers. The aim of the invention is to increase the productivity and quality of magnetic-abrasive machining of screw surfaces by creating conditions for uniform removal of material from their protrusions and depressions while simultaneously:

Description

13

Noah processing of two details. For this, two identical parts 1 are placed on parallel axes between the two pole tips 2 of the magnetic system, the smooth working surfaces of which are equidistant to the outer surfaces of the parts. The parts are brought into engagement with the guaranteed side clearance 1. rotate in one direction, and the feed tips are reported to the pole pieces. The location of parts and the shape of pole pieces

one

The invention relates to abrasive machining, in particular to the magneto-abrasive machining of rotation bodies having an external screw thread, and can be used in mechanical engineering as a finishing operation in machining worms, power and propellers.

The purpose of the invention is to increase the productivity of the magnetic abrasive machining of the external screw surfaces of the parts by creating conditions for the uniform removal of material from their projections and depressions while simultaneously processing two parts.

FIG. 1 shows a diagram of processing parts with a screw thread depth of more than 3 mm; in fig. 2 is a diagram of processing parts with a screw thread depth of less than 3 mm.

Two identical parts 1 with an outer screw surface are placed on parallel axes in a working zone formed by two pole pieces 2 of a magnetic system (not shown). The parts are brought into engagement with each other, providing a constant guaranteed gap between the lateral surfaces of the coils O 0.3-1.5 mm, the value of which is chosen depending on the depth of the screw thread and the processing circuit, i.e. the parts set the center distance between them

S

  ,,, -; -,

sin --76

the cutting depth is determined: when the cutting depth is more than 3 mm, the parts are positioned so that in cross section the straight line connecting their centers is perpendicular to the axis of symmetry of the pole pieces (90), and the side clearance is chosen in the range of 0.8-1 , 5 mm, with a cutting depth of less than 3 mm, the parts are set so that 1 O, and the size of the side clearance is chosen in the range of 0.3-0.8 mm. 2 hp f. 2 Il. 2 tab.

15

where d is the average diameter of the screw thread;

O - guaranteed working gap between the side surfaces of the turns;

on - angle profile of the coil in a longitudinal section.

The shape of the pole pieces 2 is determined by the processing circuit (Figs. 1 and 2) due to the condition of providing a constant working gap between the outer surfaces of the parts and the smooth running surfaces of the pole pieces.

When processing parts m 1, synchronous rotation is set in one direction, and pole tips 2 are reported with a longitudinal feed movement, the speed of which depends on the material of the part, initial roughness value, magnetic induction value and does not depend on screw cutting parameters,

Ferroabrasive powder is fed to the working area. The removal of metal in this case occurs in three zones for each of the parts 1: in the zones covered by their pole pieces 2, where processing takes place along the diameter of the protrusions and sides of the turns at a small distance from the top; and in the engagement zone, where the side surfaces of the coils and the bottom of the valleys between the coils are machined. (Machining of the entire part occurs as the pole pieces move). To ensure uniform machining of the screw surfaces,

25

thirty

nivuyus with respect to R

and maize.

in

the cutting cavity to R at its top, which should not be n,) 1.5

RC

(-Ifl- ii. 1,5), should be used as “c. Bpepui

call a different location in the work area of parts with different screw thread depths.

Thus, when machining external helical surfaces with a cutting depth of more than 3 mm, parts 1 are positioned so that in cross section the straight line connecting their centers is perpendicular (angle 90) to the axis of symmetry of the pole tips 2 (Fig. 1). The value of the lateral clearance in the mesh is chosen in the range of 0.8-1.5 mm. With this arrangement of parts, the bulk of the ferroabrasive powder accumulates in the zone of engagement of parts and provides intensive processing of deep depressions.

When machining helical external surfaces with a cutting depth of less than 3 mm, the arrangement of the details of FIG. 1 results in an increase in tapering due to the presence of a large amount of powder in the engagement zone and uneven processing. Therefore, parts should be arranged in accordance with FIG. 2, i.e. so that in cross section the straight line connecting their centers coincides with the axis of symmetry of the pole pieces (angle / 3 O) and the side gap should be chosen in the range of 0.3-0.8 mm. In this case, the main treatment occurs in the areas of overlap of parts with pole tips, and in the area of engagement only the additional processing of depressions occurs. A caricature phenomenon is not observed in this case, since much less powder is accumulated in the engagement zone than with the treatment in FIG. one.

Examples p. Machines with trapezoidal cutting with an outer diameter U 40-62 mm, pitch up to 10 mm and cutting length up to 400 mm are processed. When processing supported: number

in

ep 1,5

l13101764

Revolutions rpm; longitudinal feed of pole pieces 1.2 mm / rev; cutting speed 100 - 118 m / min.

In tab. Figure 1 shows the effect of the position of parts relative to the pole of the tips on the uniformity of processing; in tab. 2 - influence of the size of the working gap 8.

Claims (3)

1. An abrasive machining method in which two identical parts are placed on parallel axes in the working area with an abrasive medium and they are given a rotation, characterized in that, in order to increase the productivity with magnetic-abrasive machining of external helical surfaces of the parts, placed between the two pole tips of the magnetic system, the working surfaces of which are equidistant to the outer surfaces of the parts, the parts are meshed with a guaranteed side clearance and rotated synchronously in one direction ION. 2. A method according to claim 1, characterized in that, in order to ensure uniform machining of the screw outer surfaces with a cutting depth of more than 3 mm, the parts are arranged so that in the cross section the straight line connecting their centers is perpendicular to the axis of symmetry pole pieces, and the amount of lateral clearance is chosen in the range of 0.8 1, 5 mm. 3. The method according to claim 1, which is different from the fact that, in order to ensure uniform machining of the screw outer surfaces with a cutting depth of less than 3 mm, the parts are positioned so that in the cross section of the straight line connecting their centers with the axis of symmetry of the pole pieces, and the size of the side gap is chosen in the range of 0.3-0.8 mm. Continuation of table 2 Editor I. Casarda Compiled by II. Malkhazov Tehred L.Oleynik Proofreader L. Patay Order 1853/13 Circulation 716 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d, 4/5 Production and printing company, Uzhgorod, st. Design, And