SU1759609A1 - Method of finishing parts - Google Patents

Abstract

Use: for abrasive machining of flat parts on vibratory lapping machines. The parts are positioned in a water jet installed between the finishing discs that perform circular translational oscillations. On the annular working surface of the finishing discs, a surface equal to the total area of the workpiece is limited by two radii. Then they are tightly placed in the formed figure in the form of an annular sector on the working surface of the finishing disc, fixing the magnitude of the radii of their centers of location. After that, the workpieces are evenly distributed over the working surface of the disk, without changing the values of the radii of their centers. 1 il.

Description

The invention relates to abrasive machining and can be used in fine-tuning the flat surfaces of parts. and finishing drives.

The closest to the invention to the technical essence and the achieved result is the method implemented in the finishing machine, which consists in the fact that the workpieces are located in the drive located between the two finishing discs that perform circular antiphase oscillations.

The disadvantage of this method is the reduced cost-effectiveness and productivity of the finishing process due to the need to periodically stop it in order to carry out forced editing of the finishing disks.

The aim of the invention is to improve the quality and productivity of the finishing process by ensuring uniform wear over the entire width of the working surface of the finishing discs.

The goal is achieved by the fact that in the proposed method of fine-tuning the flat surfaces of parts by fine-tuning disks making circular translational oscillations, on an annular working surface of fine-tuning disks with two radii limit the surface equal in area to the total area of the parts being machined, and then the working surface of the finishing discs, the machined parts are placed tightly, the radii of their location centers are fixed, and then the machined Hoists are evenly distributed over the working surface of the finishing discs, without changing the values of the radii, the location of their centers.

The proposed method is carried out as follows.

On the annular working surface of the finishing discs, two radii limit the surface equal in size to the total area of the workpiece.

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then the processed parts are tightly placed into the formed figure in the form of an annular sector, and the radii of their centers are recorded.

After that, the workpieces are installed in the carrier jacks located between the finishing disks, uniformly over the entire working surface of the finishing disks, without changing the values of the radii of their centers,

Then the finishing discs are informed by circular translational oscillations, for example, by means of a vibrodrive, while the carrier performs a slow rotational movement of the feed around the axis of the discs.

In the process of fine-tuning, each point of the finishing disks makes circular translational oscillations of the same amplitude, as a result, when the workpiece is a ring equal to the working surface of the finishing disks and is in constant contact with the working surface of the disks, wear U at any point contact is calculated by the formula:

U k p- I.

where k is the technological coefficient;

p is the specific pressure at the point under consideration;

L is the path traveled by the point in question over a period of time t.

If the values of k and p are unchanged, then in the finishing machines, the disks of which perform rotational movements, the points of the disks located on different radii will pass through different paths in a unit of time, as a result of which there will be different wear at these points, and According to the proposed method, all points have the same circular trajectories of motion, therefore, the same paths will follow the same time unit and therefore the wear of the working surface of the finishing discs is the same at all points and its value depends on the time of contact and t between the finishing discs and the workpieces, i.e.

U f (t),

Under actual conditions, parts are placed in the sockets of the separators installed in the carrier, and therefore it is almost impossible to arrange them in the form of a continuous ring part, and also, due to the need to ensure certain specific pressures on the surface

parts, the area occupied by the parts to be processed is usually some of the surface area of the finishing discs.

In this case, depending on the location of the workpieces in the driver, different points of the finishing discs will be in contact with the parts for different times, and therefore the working

the surface of the finishing discs will wear unevenly, which is present in the prototype.

To ensure uniform wear throughout the work surface

The disks require that during the processing cycle each point of the finishing disk located on different radii should have the same time in contact with the parts to be processed.

This result can be achieved by placing the parts in the carrier according to the proposed method, and to prove this, consider an arbitrary annular sector of the working surface of the finishing disc, shown in the drawing.

The surface occupied by the arcs I and L of the ring sector is divided into elementary areas AS D1 Dg, which we take as the contact points between the finishing

discs and workpieces.

The contact time Ati of the elementary areas D S, of the finishing disk, located on the arc, with the parts being processed during the processing cycle T

is calculated by the formula:

AS-HI

2 gdg

T

D |

P1

2 g

where ni is the number of elementary areas (contact points) occupied by the parts to be machined on arc I and, accordingly, the contact time DF of elementary areas D S of the finishing disk located on arc L with the parts to be processed over the processing cycle T is calculated by the formula:

At. AS-nzAl-nz

 “A I - I,

2jrR Dg

2l- R

where P2 is the number of elementary areas AS (points of contact) occupied by the parts being processed on the arc L. And since these time periods must be equal, let's equate them

T

D | P2

2n -R

T

P2

g

    D2 IR J 2 P 2 lt m r And

Thus, for the contact time of the contact points of the finishing disc with the parts to be treated to be equal, and consequently for the same wear, it is necessary that their number be proportional to the lengths of the circles on which they are located.

This condition is satisfied only for the ring sector figure. To prove this, consider an arbitrary ring sector.

The lengths of the arcs I and L of such a figure, on which the points of contact of the finishing disc with the parts to be processed are located, are calculated by the formula:

. g and l R and l

I - and L - -

180 ° Check the ratio

180 °

R an 180 °

130 ° r al

The result is

I r

P2

HZ

Consequently, if the workpieces are installed in the shape of the ring section on the working surface of the finishing disc, then during the processing cycle T, the same wear will be ensured over the entire width of the working surface of the finishing disc and

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15

20

five

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five

the goal of the claimed method will be achieved. The injected method was implemented on the finishing machine (4,5).

The processed parts, ceramic substrates of rectangular shape, are placed in the windows of the carrier, located between the cast-iron finishing discs. The total area covered by the batch of machined parts was 10% of the total working surface area of the finishing discs, and the initial non-flatness of the working surface of the finishing discs with a diameter of 500 mm was within ± 2 µm. The process of refining was carried out for four cycles of 30 minutes at a specific pressure of p 0.48 kg / cm2, the abrasive was diamond paste АСМ10 / 7 with a kerosene diluent.

As a result of the tests carried out, changes in the non-flatness of the working surface of the finishing discs were not detected within the limits of the accuracy of the measuring instrument, and the non-flatness of the machined parts improved on average 2-4 times.

Claims (1)

The invention of the method of finishing parts on the vibrostane-kzh. in which they are placed between two discs and reported to the parts and discs relative displacements differing in that. that, in order to increase productivity and quality of finishing, the number of workpieces is selected from the conditions corresponding to their total area of the ring sector of the priter, while the parts are evenly placed on the priter around the circumferences, the radii of which are equal to the radii of their location in the said ring sector. cc