SU1313653A1 - Method for abrasive treatment - Google Patents

Abstract

The invention relates to methods for producing a regular microrelief on treated surfaces such as bodies of revolution. The aim of the invention is to improve the quality of the treated surface. A regular microrelief is formed with a grinding wheel 1 with a working surface in the form of a helical groove with a step equal to a given step of the microrelief and with a radius of profile j5 (1: 8-R), (1-ff), while ensuring a constant ratio of the frequencies of rotation of the grinding circle 1 and billet 2 and the cross feed ratio of billet 2 to the pitch of the helical groove of circle 1 as an integer, and then make the final finishing operation and remove the seam allowance equal to h (R): (lf), where I is tay 1 - given relative reference length profile; R is the specified height of asperities. 3 il. o "5 (L .1 G-: -vf, ::.. - ....".. -. I / xAV, t,, -. L - // 9Sd ..-. - J 00 with a a 00 uz.2

Description

113

The invention relates to mechanical engineering, more precisely, to methods for producing on machined surfaces such as rotation bodies, for example, on raceways of bearings, on shafts, on inner surfaces of cylinders, etc., of a regular microrelief.

The aim of the invention is to improve the quality of the surface by applying a grinding wheel with a working surface in the form of a helical groove with a step equal to the step of the microrelief, followed by a final finishing operation with a calculated value of the allowance.

FIG. 1 shows a diagram of the formation of a regular microrelief in a grinding operation; in fig. 2 is a diagram of the final formation of a regular microrelief in a debugging operation; in fig. 3 - single microroughness.

To determine the radius f of the profile and the size of the allowance h, we use FIG. 3, where denoted: R - the required height of asperities; I - microscopic irregularity; h - required relative reference profile length; B is the area of microroughness; H is the height of the microroughness after grinding.

Profile radius is

f r (f-H) 2. CD

Transform the expression (1) and neglect due to the smallness of the value of H ,, we get

(2) (3) (4)

, 2

Substituting expression (2), we get

J2

R )

8 (R4gl-)

Transforming tea

about 2 g p 2

fR-V- | -

from where we get expressed

).

8R Of known ratios

B

3653

p2 P 8H

(ten)

we get

(eleven)

B2

Substituting and transforming, we get an expression for h

 D

(12)

B- An example of a specific application of the proposed method is the process of forming a regular microrelief on the raceways of the inner rings of ball bearings No. 206.

in order to increase the bearing durability on the track surface, it is necessary to obtain a regular micro-relief with a pitch of 3 mm, a relative length reference profile of 0.8 and

height irregularities um ..

Before the grinding operation, the circle is trimmed with a diamond in a frame with a radius of apex.

five

0

About 3 f 2 mm

 m / min

2 10-3 and axial diamond feed 0.3 mm / rev.

The grinding of the raceway is carried out by plunging with a cross feed S (Fig. 1). From the conditions of annealing-free productive grinding, the ratio of the speeds of the circle and the workpiece should be about 60. The rotational speed of the circle on the machine is 1900 rpm, the speed is 35 m / s. Then speed 5. Procurement bo

and its frequency of rotation with a diameter of mm

J 5714-40 Accepted p / p 5 and rpm.

If grinding is performed with a whole frequency ratio of grinding wheel 5 and workpiece 2, then the step of the unevenness of the workpiece is equal to the pitch of the helical groove of the wheel, since each point of the surface of the workpiece meets one 0 point of the working surface of the wheel. The height of the irregularities (Fig. 1) of the workpiece after grinding is equal to

h,

 364 rpm

12 о 42 о H i- --ii- 5 5-10 8р 8-2 -

mm

55 If this ratio is not integer, then the profile of circle 1 in this cross section of workpiece 2 is shifted in time in the axial direction, and the pitch and height of the irregularities are different than on top3 .1

regular circle micro-sensitivities 1-,

Eph can not be obtained.

After grinding, we finish the surface (fig. 2) of superfinishing with removal of the allowance for the side

0.82.2-10h - - 305-10mm.

1-0,82

Such an allowance is usually removed at the operation of superfinishing. After superfinishing, the relative reference profile length is equal to

b 2V2-2-3,3-10-3 a O 8 ,.

0.3

and the height of the irregularities

1-5

gz

, 5 10- -3,5 10- 2 ..

This process is completed, and on the surface of the workpiece is obtained a regular microrelief with specified parameters.

If a regular microrelief is applied to a surface of relatively large extent, then grinding of such a surface should be done with a transverse feed of the workpiece relative to the grinding wheel.

ten

f5

0

four

Claims (1)

The invention The method of abrasive processing, which includes two stages: preliminary - grinding and final - finishing, which is characterized by the fact that, in order to improve the quality of processing by forming a regular microrelief on the surface, a shli, a fovalny circle, is taken as a tool at the preliminary stage with a screw groove on its working surface with a radu22 som p g- () with this ratio 4acTdiT of rotation of the circle and the workpiece and the magnitude of the steps of the longitudinal feed and the helical groove are chosen multiples of, and at the final stage, the value of the allowance is chosen by the formula  8p where I is the specified step of asperities; H - given relative reference length profile; R is the specified height of asperities. Fie. / (re.e. Compiled by A.Shutov Editor T.Parfenova TehredL.Serdyukova Corrector S.Cherni  ™ ----- | .1-г г г 1-1 - гш Order 2167/15 - Circulation 716 Subscribed by VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, 4/5 Raushsk nab. Production and printing company, Uzhgorod, Projecto st., 4.