SU1335436A1 - Method of dressing a grinding wheel - Google Patents

Abstract

The invention relates to the field of engineering. Its purpose is to improve the quality of straightening diamond wheels with spherical tops of the grains. At the same time, the working surface of the circle is periodically affected by a plate of a material that is adhesively active to diamond, oscillating in the direction normal to the surface of the circle. The impact is ensured by grinding around the plate, stretched to stresses less than the yield strength 1.3 times, and preheated to a temperature of 100-300 ° C, with the grinding depth greater than the thickness of the oxide film on the plate and less than the radius of the tops of the grains. 2 ill., 1 tab. co-eaten 4 CO a

Description

The invention relates to mechanical engineering and can be used in grinding parts mainly from hard-to-cut spars.

The purpose of the invention is to improve the quality of editing diamond wheels, grains of which have spherical tops,

An elastic plate heated to 100–300 ° C for a time sufficient for the formation of an oxide film and an oscillation of the plate in the direction perpendicular to the surface of the circle, while polishing its surface with a certain depth, is used as a ruler.

Fig. 1 shows the scheme for the implementation of the proposed dressing method; figure 2 - grain in contact with the plate.

The diamond wheel 1 is edited by periodically exposing its working surface to the control element 2 of a material adherent to the diamond, oscillating with amplitude L in the direction normal to the surface of the wheel. The impact is ensured by grinding around the specified right element in the form of a non-rigid plate, stretched by force P to stresses not

higher yield strength, and nag I

retreat to a temperature of 100-300 ° C, and the grinding depth t lies within

a t R,

where a is a thick oxide film;

R is the radius of the spherical vertex

(rounding) of grains. The essence of the method consists in the formation of optimal microgeometry of abrasive grains. When grinding an elastic plate, the latter starts to oscillate in a plane, normal to the plate, i.e. in the plane of the circle. This ensures that the abrasive grains are periodically affected by the metal being processed. When the plate is heated, its surface is covered with an oxide film, which prevents direct contact of the front surface of the grain with the metal being processed. When grinding, the grain shifts the film and forms a juvenile surface, which adheres to the lower and back surfaces of the grain, which are not covered by the film, and destroys

yu 15

20

25 ZO

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35

40

45

50

55

4362

em them. At the same time, the grain acquires a Kli juvidnuyu form, and itself does not collapse.

Heating the plate provides for the formation of an oxide film with a thickness sufficient for shielding the front surface of the grain from the metal being processed, reducing the strength and making the adhesive activity of the metal. Heating the plate also increases the temperature in the cutting zone and reduces the elastic modulus of the material. Dp of most metals adhesion to diamond (alloyed steels, titanium alloys), the formation of oxide films with a thickness sufficient for screening w grains (3–20 µm), is provided by heating between two passes (5–8 s) up to 100-300 C. Exceeding these boundaries leads to an increase in temperature in the cutting zone to the temperature of graphitization of diamond, as a result, the front parts of the grains can also be destroyed. At a temperature of less than 100 ° C, the rate of formation of the oxide film by the film is low and its required thickness is not achieved.

Stretching the plate reduces its surface strength (hardness, resistance to micro-cutting), increases the adhesive and chemical activity of the metal of the plate and reduces its damping properties. As a result, the rate of formation of the oxide film increases, the wear of the front surface of the diamond grains decreases, and the oscillation frequency of the plate increases. These phenomena provide an improvement in the quality of editing — forming for editing grain with the removed back surface, i.e. in shape approaching the blade tool. The grinding depth t must be greater than the thickness of the oxide film a, formed when the plate is heated and interacting with the oxygen of the air, after each pass so that the grain can interact with the metal of the plate. The excess of the grinding depth of the rounding of the grain leads to an intensive process of sanding. Stretching of: the voltage in the plate should not exceed 0, 75, since at high stresses for some metals hardening of the surface occurs.

An evaluation of the effectiveness of the proposed straightening method was made by a device in which a plate with dimensions of 200x3 mm mm of titanium alloy was stretched to stresses of 0.65 h. The device was installed on the machine table and the plate was polished in a circle with dimensions of 250x10x76 mm. The electric current passes, the plate was heated to 80, 105, 200, 280 and that was controlled by a thermocouple. When straightening, the grinding of the plates was carried out in the following mode: t 0.006 mm (the thickness of the oxide film on the plate is 0.002-0.005 mm, the radius of rounding of the vertices of the diamond grains before straightening

Attitude

R / R V g

 2.42 1.95 1.72 1.70 1.70 2.02

Thus, due to the use of a stretched heated plate as a ruler and the excitation of its oscillations by grinding with a specified depth, the quality of the straightening is confirmed, confirmed by the data on the cutting ability of the wheels shown in the table.

Claims (1)

Claim 1 The method of dressing the grinding wheel according to which the right element of the material of the adhesion-active material of the abrasive grains is supplied to the working surface of the circle and excites its oscillations in the direction (03-0.08 mm); V, 35 m / s; V, 5 m / min; S 10 mm / stroke. 20-25 g of metal was removed from the plate for straightening. The quality of the edits was evaluated during subsequent grinding of the steel against the forces of Py / P measured by a dinomonometer. Grinding was carried out on a mode: 35 m / s; V, 10 m / min; S 2 mm / stroke; t 0,025 mm. The table shows the P, / P ratios for grinding after straightening with different plate heating temperatures and after straightening according to the known way. perpendicular to the surface of the circle, characterized in that, in order to improve the quality of the diamond wheel with spherical  By the top of the grains, as a right element, a plate stretched to a stress less than 1.3 times lower than the yield point is heated to a temperature of 100– for a time sufficient to form an oxide film 3 20 µm, and the excitation of oscillations is carried out by grinding the plate surface with a cutting depth exceeding the thickness 45 oxide film, but a smaller sphere radius on the top grains. -o c o- l 2 R MNR I ffo 7 Onisnay Plen1 R  I I with / / VffG / 77g v Editor V. Petrash Compiled by N. Ermakova Tehred L. Oliinyk . Order 4009/16 Circulation 714 Subscription VNSHPI State Committee of the USSR on inventions and discoveries 113035 ,, Moscow, Zh-35, Raushsk nab, 4/5 Production and printing company, Uzhgorod, st. Project, 4 Corrector C, Shekmar