FR2505709A1 - Method of forming regular micro-relief on shaft - uses intermittent shaft rotation and axial shift with grinding wheel oscillating radially - Google Patents

Abstract

The rectifying process uses a rotating grinder (1) to form a surface (2) in regular micro-relief on a workpiece (3), the formed surface incorporating separate cavities (4). An application is to the formation of friction-reducing oil-retaining cavities on a shaft journal, the peripheral grinder cutting surface being applied periodically to the surface of the work whilst the plane of grinder rotation follows the direction of grinder displacement relative to the work i.e. parallel to the work surface. Work in the form of a revolutionary body (e.g. a cylinder) may be rotated and displaced axially to effect the relative displacement in two directions (A&E), the grinder and the work having common planes of rotation. Periodic contact may be brought about by oscillation (B) of the grinder on an extension of a work radius and may take place during pauses in work movement.

Description

 The present invention relates to the machining of metal parts by abrasion and particularly to objets a method of forming, on the surface of parts, a regular microrelief composed of separate recesses, a tool head and a grinding wheel for carrying out said method, as well as parts processed according to said method. The invention is preferably applicable in mechanical constructions in order to obtain oil pockets on the friction surfaces.

 In modern mechanical constructions, great attention is paid to the characteristics of use of the friction couples, which are primarily a function of the properties of the surfaces in contact. One of the techniques for improving the bearing capacity and reducing the coefficient of friction of the torques mentioned is that of forming on the surfaces in contact a regular microrelief composed of grooves or of separate recesses. These recesses and grooves serve as reservoirs oil and supply the mobile oil seal when the d2 arrival thereof is insufficient, allow the distribution of the oil on the surface and, thereby, the formation of a protective film; they also prevent jamming and seizure and help to increase the hydrodynamic effect between the friction surfaces.

As traps for metal and abrasive particles and for dusts, the recesses and grooves make it possible to counteract their wear effect on the friction surfaces. Sometimes, it is enough to form a regular microrelief on the surface of a piece to render unnecessary its finishing treatment. The properties just mentioned, as well as a whole series of other advantageous characteristics conferred on the mobile joint by the microrelief, depend on the shape and dimensions of the latter, on the ratio between the total area that it covers and the total contact area of the friction surfaces.Also consider the depth of the microrelief, its roughness, and the profile of its grooves and recesses, especially the elevation angle, that is to say the angle between the surface to be machined and the wall of the groove or recess at the intersection thereof and said surface.

 It should be noted that the existing methods for machining the surfaces of parts either do not make it possible to form a microrelief with predetermined parameters calculated, or they are very small or have only a limited field of application and can not, therefore, , fully meet the needs of the industry.

 An example of a process belonging to the first of these categories is that of the formation of a microrelief of oil retention by shot blasting of the rubbing surface, resulting in recesses whose arrangement and dimensions have a very random nature. and are therefore unpredictable.

 Also known is a method of obtaining, on the surface of a workpiece, grooves forming a microrelief by depressing a spherical deformation tool during relative movement (rotary, translational and reciprocating) with respect to the piece being machined (see, for example, United States Patent No. 3735615).

 The microrelief obtained in this way is a network of sinusoidal helical grooves whose relative disposition can be predetermined between a wide range and whose dimensions can be calculated beforehand.

 The method considered is generally applied only in the case of parts made of relatively soft and plastic materials, its implementation for the machining of hard materials requiring the use of diamond-shaped tips that do not allow to obtain only narrow grooves. When it comes to fragile materials, the process is not applicable at all.

 The grooves obtained in accordance with the method on the surface of, for example, the shaft of a bearing assembly, have the disadvantage of bringing the high pressure and low pressure areas of the bearing into contact with each other. thereby reducing its hydrodynamic capacity.

 There is also known a method of forming, on the surface of a workpiece, a microrelief composed of separate recesses (see lai Orlov "Osnovy konstruirovania", vol 2, Nashinostroanie, 1977, N. pp. 388-390 ). This method consists in forming recesses by depression of rounded protruding knobs, during the relative movement of the tool and the part relative to each other and parallel to the surface during machining.

 The regular microrelief thus obtained is free from the aforementioned drawback of the microrelief composed of grooves.

 However, the scope of this process is also limited, in general, to parts made of soft materials and plastics. The use of diamond elements to widen said field would result in a considerable increase in the cost price of the tools and a strong limitation of the dimensions of the recesses.

 The considerable efforts of entoncesent make the process in question inapplicable, in particular, in the case of thin-walled parts. This is because deformation of the parts can then occur as a result of these efforts.

The machining of workpiece surfaces by any of the foregoing plastic deformation methods is inevitably accompanied by an expulsion of a portion of the metal out of the grooves and recesses and by the formation, around said grooves and recesses, of excrescences or burrs that can reach tens of microns. Because during such machining there is a work hardening of parts during machining and parts thereof, including said protuberances, parts
and excrescences, which are endowed with hardness, play during the exploitation of the pieces of sand of abrasive particles interposed between the friction surfaces, and promote rapid wear thereof.To counteract this disadvantage, an operation must be provided. additional to remove growths and burrs. However, this operation is impractical in practice, because the dimensions of the growths are very small and commensurable with the manufacturing tolerances.

 The invention therefore relates to a very economical method of forming, on the surface of parts, a microrelief composed of separate recesses, which method would improve the quality of the surface to be machined by preventing the appearance of growths on this, and expand the range of parts may Other machined, without increasing their manufacturing cost, these benefits being due to the choice of another mode of machining. The invention also relates to an entire tool-holder and a grinding wheel which, by forming a particular cutting surface, would make it possible to obtain, on the surface of the pieces, a regular microrelief in accordance with the mentioned method.

 The problem thus posed is solved by a method of forming, on the surface of parts, a regular microrelief composed of separate recesses, of the type in which a relative movement of the tool and the workpiece is carried out parallel to the surface to be machined.

According to the invention, the regular microrelief is formed by grinding by means of an abrasive abrasive wheel, which periodically acts, by its peripheral cutting surface, on the work surface of the workpiece, said grinding wheel being arranged so that that its plane of rotation coincides substantially with the direction of said relative displacement.

 The fact of obtaining the recesses of the microrelief by grinding and not by plastic deformation makes it possible to improve the quality of the machined surface by preventing any formation of excrescences thereon. This helps to improve the operating characteristics of the friction surfaces by eliminating one of the factors causing premature wear thereof.

 Substituting rectification by using tools of ordinary abrasive materials makes it possible to extend the field of application of the microrelief process even more extensively on parts with a high surface hardness (HRC). order of 60 and over) whose machining according to known techniques usually requires small tools, on parts of fragile materials can not at all In addition to the plastic deformation (for example, white cast iron) and parts Thin walls for which known techniques have proved inapplicable.

 Another advantage of the process according to the invention is that it makes it possible to confer a constant character on the oil retaining properties of the surfaces provided with the regular microrelief, which is due to the constant roughness of the surfaces of the recesses themselves. because they are not in direct contact with any other hard surface and therefore are not subject to wear.

 In order to increase the efficiency of the process, when it is desired to form a microrelief on the surface of a workpiece, in the form of a body of revolution, it is rational for the workpiece to be rotated and advanced axially.

In this case, it is appropriate to dispose the grinding wheel so that its plane of rotation coincides substantially with the plane of rotation of the part.

 It is possible to implement the method so that the periodic action of the cutting surface of the grinding wheel on the surface being machined is obtained by contacting the workpiece and the grinding wheel with a relative oscillatory movement in the plane. of rotation thereof and in a direction substantially perpendicular to the surface of the workpiece at the machining location.

 Then the periodic action of the cutting surface of the flange on the surface being machined can occur either during breaks occurring in the relative movement of the clamp and the grinding wheel parallel to the surface being machined this displacement having an intermittent character, is simultaneously with said relative displacement, ai it has a continuous character.

 This mode of implementation of the method makes it possible to obtain a microrelief whose recesses are in the form of segments of circle of diameter equal to or close to that of the grinding wheel. This is why this embodiment is especially applicable when relatively short recesses and relatively high elevation angles are desired.

 It is advantageous that the periodic action of the cutting surface of the grinding wheel on the surface being machined is obtained by rotating the axis of the grinding wheel about a fixed axis parallel to the latter. Then the grinding wheel must be previously adjusted according to the desired depth of the microrelief and the piece must be advanced along the surface to be machined.

 This iodine of embodiment of the invention makes it possible to simplify substantially the design of the devices used for the implementation of the method, or to have recourse to a universal metal cutting equipment.

 In this embodiment of the method, the part can be animated by an intermittent movement whose speed is given to the speed of rotation of the axis of the grinding wheel so that the action thereof on said part occurs at the moments of stops of the latter, or the piece can be animated with a continuous movement along the surface to be machined. The machining of the part during its continuous movement is more advantageous, because it makes it possible to use, to form the microrelief, universal grinding machines without special auxiliary devices for fixing the workpiece.

When the axis of the grinding wheel is rotated about a fixed axis which is parallel thereto, a microrelief is obtained, the recesses of which have a small curvature of their walls and, respectively, a small angle of elevation. This kind of microrelief formed on the friction surfaces of parts used in the support assemblies, contributes to the appearance of a considerable hydrodynamic effect. This is the reason why the embodiment of the invention is mainly advantageous in the case of formation of oil pockets on the friction surfaces of the hydrodynamic bearings used in the spindles of the tool-machines and in the abundant friction-oiling assemblies whose relative sliding speed exceeds 1 m / s
The periodic action on the surface during machining may also be performed by a grinding wheel whose axis of rotation is immobile and whose cutting surface is composed of distinct portions arranged at a certain pitch on the periphery of the grinding wheel. This machining mode makes it possible to obtain recesses i elevation angles somewhat larger than in the previous embodiment, the length of said recesses being either the same or greater. For this reason, this mode of implementation of the method is preferable when, by producing a microrelief on the friction surface, it is possible to obtain a limited hydrodynamic effect and a maximum oil retention capacity of the mobile seal; it is applicable in particular for machining the surfaces of the flat slideways of machine tools for machining metals by cutting.

 The problem described above is also solved by a tool head for the formation of a regular microrelief by the method of the invention, intended to equip a machine tool for machining metals by cutting. According to the invention, said head comprises a plate adapted to be fixed on the spindle of the machine tool, abrasive grinding wheels having a peripheral cutting surface rotatably mounted on said plate and disposed regularly around the periphery thereof, satellites rigidly secured wheels, and a central pinion meshing with planet gears and arranged for fixing on the stationary part of the machine tool.

 This design of the tool head, at the base of which is the planetary principle of transmission of the rotation, makes it possible to obtain the most economical and simple of a multi-linker composed of separate recesses by implementing the embodiment of the invention. The method according to the invention provides rotation of the grinding wheel having a continuous cutting surface. It is advantageous that these tool heads are used to obtain a deep microrelief of 0.02 n and more.

 The problem described above is also solved by the development of a grinding wheel for the retention of a regular microrelief in accordance with the method of the invention, characterized, according to the invention, in that the grinding wheel comprises work elements having portions of the cutting surface of the grinding wheel, which portions are arranged at a certain pitch along the periphery thereof, the plane severing said grinding wheel perpendicularly to its axis of rotation comprising said portions, in number of 1 i 4, whose length is not greater than 11/12 of the length of the periphery of the cutting surface, and the pitch of the portions, depending on the periphery, being a function of the predetermined pitch S of the microrelief along the surface to be machined and varying from 24S to 600 S.

 Conceived in this way, the mold makes it possible to obtain a microrelief composed of separate recesses by means of ordinary universal equipment by implementing the r6gS e8 and technological possibilities of which this equipment disposes. It is rational to use this wheel when a microrelief of depth not exceeding 0.06 n is needed.

 How to limit the number of portions of the cutting surface, which in this case is the number of working elements in the plane sectioning the wheel perpendicular to its axis of rotation, is the condition to be met to obtain a microrelief. Exceeding the upper limit normally results in each subsequent work item cutting off the entire portion of the surface layer of the part that the previous work item did not touch, and you can not then to obtain any microrelief or one obtains one whose depth and pitch are less than those prescribed.

 The limit which has been imposed on the length of a separate portion of the cutting surface is, in principle, conditioned by the same factor, with the sole difference that, said length exceeding that which appears as the upper limit, the unaffected portions of the surface layer of the part are cut by the same work element and not by the neighboring one, which is due to the very small gap separating its terminal and initial zones.

 The way in which the pitch of the portions of the cutting surface depends on the predetermined pitch of the microrelief is determined in principle by several variable parameters.

These are: the depth of the microrelief, the diameter of the grinding wheel, the movement speeds of the tool and the workpiece.

In each particular case, this dependence can be established experimentally. The limit values mentioned above highlight the fact experimentally studied which is that it is not possible to obtain a microrelief out of the aforementioned range.

Thus, the pitch of the portions of the cutting surface of the grinding wheel (or, which is the same, the pitch of the working elements) being less than 24 S, a microrelief with predetermined parameters can be obtained only at a speed rotation of the wheel very low and, therefore, detrimental to the stability of the cutting process and likely to cause the destruction of the wheel. On the contrary, for a step greater than 600 S, the speed of rotation of the only one would be great that one could not avoid its bursting.

 It is easy to see that the tool head and the grinding wheel which has been developed for carrying out the process of the invention are based on the same principle of arrangement, according to the circumference, of the elements participating in the cutting. , principle said step by step. If, in the first case, these elements are the separate wheels rotated, the second is characterized in that they are the portions of a single grinding wheel.

 It is to this factor that the similarity of the other parameters of the considered tools is due.

 Thus, it is rational that the number of grinding wheels combined in a tool head does not exceed 4, all con. the limit number of working elements united in the grinding wheel. It is true that we sometimes obtain a microrelief composed of separate recesses when the number of mules united in a single head is 6 and even 8, but that in case the diameter of the circumference described around the grinding wheels is important (600 n and over).

On the other hand, when they are 4 in number, the obtaining of this kind of microrelief is guaranteed independently of the diameter of said circumference and optimal speeds from the point of view of the yield.

It is rational that the minimum diameter Da of the circumference described around the wheels of the tool head and passing through the points of their cutting surfaces farthest from their axes of rotation, be chosen equal to 200 sz so as to ensure a solidity the same considerations, it is rational that the minimum diameter D of the grinding wheel whose portions of the cutting surface are arranged in a certain pitch is chosen to be 50 mx, and that for depths greater than 0.005 m it is be established according to the following empirical formula
DILOOLI + (h - 0.01). 100 3 n where h is the predetermined depth of the microrelief
to obtain.

 It is advantageous that the edges of the cutting surface of the grinding wheels of the tool head, as well as the respective edges, seen in cross sections, of the working elements of the grinding wheel whose portions of the cutting surface are arranged according to a certain step, be rounded to a radius of 1 to 3 la.

 This makes it possible to obtain a microrelief, the recesses of which have an invariable profile, since all uod cations of the profile of the cutting surface are excluded during the running-in of the tool. On the other hand, this makes it possible to avoid any formation of protuberances on the portions of the surface during machining that are between the recesses of the microrelief, which protrusions may result from the possible warping of the wheel with respect to the machining direction.

 The working elements of a grinding wheel whose portions of the cutting surface are arranged at a certain pitch may be in the form of protrusions separated by recesses or in the form of abrasive portions mounted on the plate. This last case is distinguished by the simplicity of manufacture of the grinding wheel and economy of abrasive material.

 When the abrasive portions are arranged in several rows along the periphery of the plate, the portions of a circular row, which is due to their arrangement in a plane perpendicular to the axis of rotation of the grinding wheel, are displaced, depending on the circumference, compared to the portions of the neighboring row.

 This mode of arrangement can also be used for the grinding wheels united in the tool head when they form several rows. This improves the dynamic characteristics of operation of the tool considered.

 The preferred embodiment of the grinding wheel having portions of its cutting surface arranged at a certain pitch, however, is one which comprises sliders for supporting the work elements and mounted in the plate so as to be adjustable radially, a ring blade adapted to rotate in the center of the plate, axially to the cutting surface, and hinge elements each of which is connected by one of its ends to said ring, and by its other end, to one sliders.

 This design of the grinding wheel makes it possible to compensate for the wear of the cutting surface of the working elements separating the grinders supporting said elements at the desired distance, and this, by turning the ring of a respective number of divisions on the blade. .

This embodiment of the grinding wheel allows perfect uniformity of the dimensions of the microrelief for a long period of time without replacement of the grinding wheel is necessary. Because the replacement of the grinding wheel becomes less frequent, the machining efficiency increases. This decreases the abrasive material consump- tion because it becomes possible to fully utilize the abrasive portions.

It is interesting that a grinding wheel having portions of its cutting surface disposed at a certain pitch is made of an elastic abrasive material smaller in particle size than that of the abrasive portions. The tray may then have radial housings for installing the portions mentioned and corresponding to them are formed and in depth. Once in the housing, the portions form with the tray a peripheral surface of the wheel of continuous character. The grinding wheel being made in this way, it is possible to soften the shocks accompanying each input of the work element in contact with the surface layer of the part being machined and, as a result, better conditions are obtained at the same time. In addition, it becomes possible to operate, simultaneously with the formation of the microrelief, additional treatment of the surface between the recesses of the microrelief; in particular, it is possible to remove the tops of microsaillies resulting from previous machining operations, which reduces the running-in period of the friction surface of the parts, when they are part of the support assemblies, and raises their quality to the point precision
The invention will be better understood and other objects, details and advantages thereof will appear better in the light of the explanatory description which follows of various embodiments given solely by way of non-limiting examples with references to the drawings not shown. in which
- Figure 1 shows a diagram illustrating an embodiment of the method according to the invention wherein the periodic action of the grinding wheel on the flat surface to be machined is due to an oscillatory movement of the grinding wheel relative to the workpiece;
- Figure 2 shows a diagram illustrating another embodiment of the method according to the invention, providing an oscillatory movement of a workpiece, the surface to be machined is flat relative to the grinding wheel; ;
- Figure 3 shows a diagram illustrating another embodiment of the method according to the invention, providing an oscillatory movement of the wheel relative to a workpiece having a surface of revolution;
- Figure 4 shows a diagram illustrating another embodiment of the method according to the invention, wherein it imparts an oscillatory movement of the workpiece, which has a surface of revolution relative to the grinding wheel;
- Figure 5 shows a calculation diagram of the embodiment of the method according to the invention wherein the relative oscillatory movement of the grinding wheel and the workpiece is simultaneously with a movement of intermittent translation of said workpiece;
- Figure 6 shows a calculation diagram of the embodiment of the method according to the invention, wherein the relative oscillatory movement of the grinding wheel and the workpiece is simultaneously with an intermittent rotational movement of said workpiece;
FIG. 7 represents a calculation diagram of the embodiment of the method of the invention in which the relative oscillatory movement of the grinding wheel and the workpiece is performed simultaneously with a continuous transfer movement of said workpiece;
- Figure 8 shows a calculation diagram of the variant of the method according to the invention, wherein the relative oscillatory movement of the grinding wheel and the workpiece is simultaneously with a continuous rotational movement of said workpiece;
FIG. 9 represents a nomogram for determining the diameter of the grinding wheel for the case where the grinding wheel and the part are in relative oscillatory motion with respect to each other;
- Figure 10 shows the arrangement of the recesses in a microrelief obtained on the surface of a rotating body;
- Figure 11 shows a diagram illustrating another embodiment of the method according to the invention, wherein the axis of the grinding wheel is rotated relative to a fixed axis parallel to said axis of the grinding wheel;
FIG. 12 is a diagram illustrating the embodiment shown in FIG. 11, using several grinding wheels;
FIG. 13 represents a calculation diagram of the embodiment of the method according to the invention, with rotation of the axis of the wheel around a fixed axis which is parallel to it, the part being animated by a movement of continuous relationship;
FIG. 14 represents an auxiliary calculation diagram;
FIG. 15 represents a calculation diagram relating to the embodiment of the method according to the invention, in which the rotation of the axis of the grinding wheel around a fixed axis which is parallel to it operates simultaneously with the intermittent rotation; of the room;;
FIG. 16 represents a calculation diagram relating to the embodiment of the method according to the invention, in which the rotation of the axis of the wheel around a fixed axis which is parallel to it operates simultaneously with a movement continuous rotating part;
FIG. 17 represents a kinematic diagram of a tool head according to the invention;
- Figure 18 shows a constructive diagram of the same tool holder head;
FIG. 19 is a kinematic diagram relating to an embodiment of the tool head according to the invention, in which the wheels are arranged in several rows;
FIG. 20 is a view along arrow G of FIG. 19;
FIG. 21 is a diagram illustrating an embodiment of the method of the invention, with the aid of a grinding wheel whose cutting surface comprises separate portions arranged at a certain pitch (in the case of a flat surface to be machined). );
FIG. 22 represents a diagram illustrating an embodiment of the method according to the invention, with the aid of a grinding wheel whose cutting surface comprises separate portions arranged at a certain pitch, the surface to be machined being that of a body of revolution;
FIG. 23 represents a general view of an embodiment of the grinding wheel according to the invention, in which the working elements are arranged in such a way that they can be adjusted radially;
Fig. 24 is a sectional view taken along line XXIV-] OtIY of Fig. 25;
FIG. 25 is a fragmentary view of the portion N of the grinding wheel of FIG. 23, shown on an enlarged scale;
FIG. 26 represents a general view of another embodiment of the grinding wheel according to the invention, in which the plate is made of elastic material;
- Figure 27 is a sectional view along XXVII-XrlI of Figure 26;
- Figure 28 is an axonometric view of a diagram illustrating the machining of the workpiece with a grinding wheel whose tray is elastic material according to the invention;
- Figure 29 shows a general view of an embodiment of a wheel according to the invention, wherein the plate is elastic and the work elements form several rows;
FIG. 30 is a view along the arrow P of FIG. 29;
FIG. 31 represents, on an enlarged scale, the microrelief present on a portion Q of the surface of the part given in FIG. 28 (before machining);
FIG. 32 represents, on an enlarged scale, the microrelief present on a portion U of the surface of the part given in FIG. 28 (after machining);
- Figure 33 shows a cross-sectional view of the cutting surface of the grinding wheel, when obtaining a microrelief whose recesses have a rounded profile in a plane perpendicular to the machining direction.

 The method according to the invention for forming, on the surface of parts, a microrelief composed of separate recesses consists essentially in that said microrelief is obtained by means of a rotating grinding wheel acting periodically, by its surface. peripheral cutting, on the surface to be machined, the grinding wheel and the part being in relative motion, relative to each other, parallel to said surface to be machined. The grinding wheel is arranged in such a way that the plane of its rotation is oriented in the direction of said relative displacement. This makes it possible to form, in particular, recesses whose walls rise gently from the center towards the periphery of said recesses. which best meets the established standards for the oil pockets to be formed on the surfaces of the friction parts, since the low elevation angles, observed between the wall of the recess and the bearing surface, contribute to increase the hydrodynamic effect in the friction assembly.

 The machining of a surface to obtain on it a regular microrelief is operated normally in one pass, because it is virtually impossible to evenly distribute, on the surface to be machined, the recesses obtained in several passes.

 The character of the relative displacement of the part of the grinding wheel, as well as the character of the periodic action of the grinding wheel on the surface to be machined, can vary widely.

 It should be noted that in all the exemplary embodiments of the method according to the invention, only cases of rectification by encounter displacement will be examined, although in principle a microrelief can be obtained on the surface of a piece, as well by rectification meeting or moving in the same direction. The first is nevertheless preferable, because it makes it possible to avoid the phenomenon of burnishing of the surface whose machining is carried out by the cutting surface of the tool, a phenomenon which is possible during displacement grinding in the same direction and which is undesirable. because we can not operate then by cutting.

 Figures 1, 2, 3 and 4 show diagrams illustrating the embodiments of the method according to the invention, in which the periodic action of the cutting surface of the grinding wheel 1 on the surface to be machined 2 is due to a relative oscillatory movement of the part 3 and the grinding wheel 1 in the plane of rotation thereof and in a direction substantially perpendicular to the surface of the workpiece at the machining location. The surface to be machined represented. FIGS. 1 to 3 illustrate an embodiment of the method of the invention, according to which the oscillatory movement is due to the displacement of the grinding wheel 1 in FIGS. rotation relative to the part 3, which is at the same time animated by a movement along the surface 2 to be machined. In the variants illustrated in Figures 2 and 4, the axis of the grinding wheel is motionless along the surface 2 to be machined and the oscillatory movement perpendicular to this surface being reserved for the piece 3.In all the figures that come to be mentioned, the direction of movement along the surface 2 to be machined is designated by the arrow A, the direction of the oscillatory movement being indicated by the arrow B, and the direction of rotation of the wheel, by the arrow C. In FIGS. 3 and 4, which illustrate machining cases of the surface 2 of a cylindrical part 3, there is also an arrow E indicating the direction of axial advance of said part 3.

 The displacement of the workpiece 3 in the direction designated at A can have a continuous character as well as an intermittent character. In the latter case, the oscillatory movement can also be either interbittent or continuous, but always granted, from the point of view of time, to the step of displacement of the part 3 according to the arrow A, so that the grinding wheel 1 acts on the piece 3 during pauses Intervenant when moving it in the direction indicated by the arrow A. In this case, one obtains on the piece 3 a microrelief whose recesses 4 (see Figures 1, 5, 6), seen in section of this piece by the plane of rotation of the grinding wheel 1, have the drilling of circular segments of said grinding wheel.

où D est le diamètre de la meule 1,
h est la profondeur de l'évidement 4 correspondant
à la profondeur de pénétration de lameule dans
la pièce 1. La profondeur h est la différence
entre l'amplitude a d'oscillation et la distance
initiale entre la surface 2 de la pièce 3 et le
point le plus proche de cette surface, situé sur
la surface périphérique de la meule 1.When the surface 2 to be machined of the piece 3 is flat, the length St of the recess 4 (FIG. 5) is the length of the cord of the segment and constitutes approximately (sufficient precision for the practical needs)

where D is the diameter of the grinding wheel 1,
h is the depth of the recess 4 corresponding
at the penetration depth of the lamol
the room 1. The depth h is the difference
between oscillation amplitude and distance
between surface 2 of room 3 and the
closest point to this surface, located on
the peripheral surface of the grinding wheel 1.

où t1/3 est le temps nécessaire
pour effectuer un pas, et tg, la durée de la
pause entre deux pas);
t est le temps séparant les débuts des deux oscilla
tions successives faites dans le sens désigné par
la flèche B (cas du mouvement oscillatoire
intermittent).The pitch S of the microrelief, seen in the longitudinal direction (along the arrow A), is the sum of the length S1 of the recess and the length S2 of the portion between two recesses and constitutes
S. V3t (2) where V3 is the average velocity of relative displacement of the grinding wheel (ie

where t1 / 3 is the time needed
to take a step, and tg, the duration of the
pause between two steps);
t is the time separating the beginnings of the two oscilla
successive statements made in the direction indicated by
arrow B (case of oscillatory movement
intermittent).

For continuous oscillatory movement,
(3) where T is the oscillation period;
9 is the oscillation frequency.

Thus, the pitch S of the microrelief constitutes

où \ est le temps de pénétration de la seule 1 dans la
pièce 3, égal à

où a est l'amplitude d'oscillation.If the two movements (relative movement along the arrow A and oscillatory movement along the arrow B) have a continuous character, the shape of the recesses 4 obtained is also close to that of a segment, but its radius R1 is larger than the radius R of the grinding wheel (abrasive tool), and the length S1 depends on the relative speed of movement along the arrow A (see FIGS. 7 and 8) .When the surface 2 of the piece 3 is flat (see FIG. 7) , the character of the two movements. mentioned being continuous, the length S 1 of the recess 4 can be determined by a material which is quite sufficient according to the formula

where \ is the penetration time of the only 1 in the
room 3, equal to

where a is the amplitude of oscillation.

 The pitch S can be determined then according to the formula (4) if V3 is not considered as being the mean speed of the translational movement, but as the actual speed of this motion.

 It should be noted that in the particular case where h I a, it is possible to obtain on the surface of the piece a relief called wave in which the recesses alternate with the portions of the surface well rounded.

 In practice, the relationships given above (from 1 to 6) are used to determine the diameter of the grinding wheel and the parameters of the movements mentioned, starting from predetermined dimensions of the microrelief to be obtained and based on the parameters independent of the one of the movements. This is done in the manner described in detail below in Examples 7 and 2.

ExenDle 1
In order to obtain a regular microrelief composed of recesses in segments of a length Si g 4 mm, a width b @ 5.1 and a depth h = 0.01 mm, arranged in a pitch S 8 12 mm in the longitudinal direction (in the plane of rotation of the tool) and in a pitch So 8 15 mm in the transverse direction (perpendicular to the plane of rotation), the surface 2 of a sample was subjected to machining ( see Figure 2) which was a plate of 100 x 50 x 20, made of hardened steel
Up to HRC P 60. For this purpose it was used a plane grinding machine whose table was equipped with a device 5.

 The sample (designated at 3 in FIG. 2) was installed in the device 5 on a base 6 connected kinematically to the oscillating motion mechanism 7 and mounted on slides 8 provided with a mechanism for moving stepwise (no shown in the drawings).

 A flat grinding wheel 1 was fixed in the spindle of the grinding machine. The diameter of the grinding wheel, equal to 400 mm, was determined from the nomogram (see Fig. 9) established in accordance with equation (1) and starting from a predetermined dimension of the rope, equal to 1 mm. occurrence at the length S1 of the recess, and a height of the segment equal to the depth h of the recess.

 The thickness of the grinding wheel: equal to 5 years, corresponds to the width b of the recess.

 By operating the table of the grinding machine, the sample was arranged so that the distance between the surface 2 to be machined and the closest point thereof to the peripheral surface of the grinding wheel 1 is 300 mm, one edges (right, in FIG. 2) was disposed below the axis of the spindle, and the distance between the front face of the plate and the side face of the grinding wheel was 12.5 mm.

 By putting into operation the controls of the grinding machine and the device 5, the grinding wheel was rotated at 1650 rpm while the plate was moved intermittently in the direction indicated by the arrow A and an oscillatory movement in the perpendicular direction along the arrow B. Starting from the amplitude a = 3.01 mm and the frequency = 8 1 / s, the average speed V 3 of translation movement was determined according to the formula (4 ) VI S. p. 12. 8 P 96 s / 8 1 5.76 m / min.

 The kinematic linkage between the mechanisms of stepwise movement and of escillatory movement, in the device 5, made it possible to alternate the horizontal stepwise displacement of the plate with its vertical oscillation.

 The regular microrelief having been obtained over the entire length of the plate, the device 5 was laterally displaced by 15 mm and the operation was repeated.

 The time required to obtain the microrelief over the entire surface 2 of the sample constituted 7 s.

 The microrelief obtained corresponded to the required dimensions. The surface 2 of the plate, considered at the places between the recesses, showed no protuberance or burr.

Example 2
In order to obtain a regular microrelief composed of recesses with a length S1 @ 4 mm, a width ba 5 mm and a depth hn 0.01 Ipp, arranged in a pitch S @ 15 mm in the longitudinal direction and in a transverse pitch of 50 mm, the surface of another sample similar to that described in Example 1 was subjected to machining, using equipment and An analogous tool. The sample was animated with two movements as in Example 1, with the only difference that these movements had a continuous character.

 Taking the value 28 of the frequency of the oscillatory movement as a starting value, the amplitude of said movement was determined to be 0.15 mm and the speed of the translational movement V3 was 7.2 m / min. We did this by solving equation (5) in which we introduced the value 1 of equation (6) and, as a system, equation (4).

 Then, the sample has been arranged, with respect to the grinding wheel 1, in such a way that the distance separating the surface 2 to be machined and the closest point thereof to the peripheral surface of the grinding wheel 1 constitutes 0 , 14 as. Then, by connecting the controls of the grinder and the device 5, the grinding wheel 7 was rotated at 1650 rpm, while animating the sample of the two movements mentioned above according to appropriate parameters.

 After performing a row of microrelief on the length of the plate surface 2, the device was moved laterally 15 mm and the operation was repeated.

 The total time to obtain the microrelief on the entire surface 2 of the sample was 7 s.

 The microrelief thus obtained was in accordance with the required dimensions, with a precision quite sufficient for the practical needs. The surface 2 of the plate, at the places between the recesses, was smooth and showed no protuberance or burr.

In the case of a surface 2 of revolution (FIGS. 3 and 4), the grinding wheel 1 is disposed so that the plane of its rotation is substantially in the plane of rotation of the part 3, or, in other words , so that the axes of rotation of the grinding wheel 1 and the part 3 are parallel to each other, or they form an angle determining the elevation angle of the hilicoIdale line according to which the recesses 4 are arranged on the surface of the part 3 of the type considered (FIG. 10). By rotating the part 3 according to the arrow A, the circumferential pitch S of the microrelief (FIGS. 6 and 8) is obtained, while its advancement in the direction indicated by wane E (FIGS. 3 and 4) provides the transverse pitch SO of said microrelief (FIG. 10). The value of the angle θ can be determined from a predetermined value SO of the axial pitch tg α = ##, (7) where d is the diameter of the piece 3 (in the case of a
non-cylindrical piece is the diameter of this
piece at the machining location).

Le pas angulaire #. du microrelief, considéré dans le plan de rotation de la pièce, est déterminé comme l'angle de rotatton de la pièce pendant ma durée d'une oscillation à fréquence 4 et constitue

où n3 est la vitesse moyenne de rotation de la pièce 3
en tr/mn, c'est-à-dire la vitesse correspondant
la la vitesse circonférentielle moyenne V3
Dans le cas où tous les mouvements de la pièce 3 ont un caractère continu (figure 8), la longueur Si de l'évidement 4 (suivant la corde) et le pas angulaire 6 peuvent être déterminés avec une précision tout-à-fait suffisante (la correction à apporter étant alors insignifiante et de ce fait négligeable) selon les mêmes formules (8) et (9), à cette seule différence près qu'on entend par n3 la vitesse de rotation continue de la pièce.When the piece is a body of revolution and when animated with intermittent rotation about its axis, the length S; of the recess can be determined as the length of the cord common to two circumferences, one of which has a diameter equal to that
D of the grinding wheel, and the other a diameter equal to the diameter d of the piece (see Figure 6). The effect of the axial axial advance of the part can then be neglected because it has an insignificant value. In order to determine the length of the rope mentioned, one can use the known expression (see the book written by EN Maslov entitled "Osnovy teorii shlifovania metallov", Mashgiz, M., 1951, 61, formula 36) which, using the symoles admitted in the present description, is as follows

The angular step #. microrelief, considered in the plane of rotation of the part, is determined as the rotatton angle of the part during my duration of a frequency oscillation 4 and constitutes

where n3 is the average rotational speed of part 3
in rpm, that is to say the corresponding speed
the average circumferential speed V3
In the case where all the movements of the piece 3 have a continuous character (FIG. 8), the length S 1 of the recess 4 (following the string) and the angular pitch 6 can be determined with a precision that is quite sufficient. (the correction to be made then insignificant and therefore negligible) according to the same formulas (8) and (9), with this only difference that we mean by n3 the continuous rotational speed of the part.

Example 3
In order to obtain a regular microrelief composed of long segment recesses S1 c 1.4 n wide b. 1 n and deep of h. 0,014 mm, arranged in angular pitch & = 10 and in axial pitch
S0 = = 5 mm, the surface of a cylindrical specimen with a diameter of d = 50 mm and a length of L = 80 n in chromium-nickel steel having a HRC hardness was subjected to machining. 60. For this purpose, a plane grinding machine was used, the table of which was provided with a device 9 (FIG. 4).

 The sample (designated at 3 in FIG. 4) was fixed between the tips of the device 9 which was provided with intermittent rotation mechanisies (not shown) and oscillatory movement, the two mechanisms being kinematically connected to each other. other.

 A flat grinding wheel 1 was fixed in the spindle of the grinding machine. The diameter D of the grinding wheel, equal to 150 mm, was determined according to formula (8), its thickness equal to 1 mm being chosen according to the desired width of the recess to be obtained.

 By operating the grinding machine table, the sample was installed in such a way that its end face (right in FIG. 4) is approximately opposite the end face of the grinding wheel 1, making with this last face an angle α = 1 50 determined beforehand according to formula (7). The distance separating the surface 2 to be machined and the peripheral surface of the grinding wheel 1 was 2.00 mm.

 By connecting the controls of the grinding machine and the device o, the grinding wheel 1 and the sample were rotated, which was furthermore animated by an oscillatory movement along the arrow B and an axial advance slack in the direction indicated by the arrow E. The rotation and the oscillatory movement of the sample were intermittent and were tuned with the other so that each sample rotation of a step '= 10 was followed by oscillation of said sample in the vertical plane. The rotational speed of the grinding wheel was 2200 rpm.

 Starting from the amplitude at P 2.014 se and the frequency 9 = 20 ss, it was determined that the n3 rotation speed of the sample should be 33.3 rpm.

To achieve this, formula (9) was used.

 The displacement of the table along the axis of the sample was continuous and allowed an axial advance of 5 mm / rev.

 The total time to obtain the microrelief over the entire surface of the sample was 30 s.

 The microrelief thus obtained was in accordance with the desired dimensions with a precision which was sufficient for practical purposes. No protrusions or burrs have been reported on the surface of the sample at the locations between the recesses.

Example 4
In order to obtain a regular microrelief composed of long recesses of Si 3.2 MI, wide g = 2 mm and deep 0.03 mm ha, arranged in an angular step 6 @ . 6 and following an axial pitch SO = 8 me, the surface of a cylindrical specimen with a diameter of 100 mm and a length of L = 120 in chromium steel and with a carbon content of 0.42 was machined, which had a hardness HRC P 60. For this purpose was used a plane grinding machine and a device 9 (Figure 4).

 The sample was installed as described in Example 3. In the spindle of the grinding machine was fixed a grinding wheel 1 whose diameter D P 600 was determined according to formula (8).

 The thickness of the grinding wheel 1, in this case equal to 2 n, was chosen according to the desired width b of the recess to be obtained.

 After opposing the end faces of the only I and the workpiece, the device 9 has been manipulated so that the angle (between the end faces in question is 1 "25 ') This value of the angle has been determined in advance. According to formula (7), the distance between the surface 2 to be machined and the peripheral surface of the grinding wheel 1 was 2.00 n.

 By connecting the controls of the grinding machine and the device 9, the only I was turned at the speed n P 2400 rpm, the sample being animated at the same time by three continuous movements: rotation along the arrow A, oscillatory next the arrow B, and axial advance along the arrow E.

 Starting from the oscillation amplitude a at 2.03n and the frequency θ = Δs -, the rotational speed n 3 of the sample which was to constitute in this case trias was determined. To achieve this, formula (9) was used. Moving the table along the sample axis allowed 8 mm / rev.

The total duration of microrelief obtained over the entire surface of the sample was 36 s,
The microrelief thus obtained was in accordance with the desired dimensions, with an accuracy quite sufficient for practical purposes. No protuberance or burr on the surface of the sample between the recesses was reported.

 In the embodiments of the process, as in the examples illustrating them, ordinary flat grinding wheels whose edges were rounded at a radius of 1.5 mm were used to obtain the consistency of the profile of the recesses of the microrelief to be obtained. and to prevent the formation of protrusion in case of possible warping of the grinding wheel with respect to the machining direction.

 A microrelief composed of separate recesses can also be obtained by operating according to another embodiment of the method according to the invention, characterized in that the surface 2 of the part 3 is subjected to the periodic action of the grinding wheel I of which the axis F is rotated about a fixed axis M which is parallel to it in the direction indicated by the arrow b (see Figures 11 to 16). Then the movement follow the arrow A (parallel to the surface to be machined), the part 3 is animated, may have, as in the embodiments described above, either an intermittent character or a continuous character.

 When the part 3 is animated with an intermittent movement, the speed of its displacement must be given with the speed of rotation of the grinding wheel 1 so that the action of the grinding wheel 1 on the surface 2 to be machined is exerted during the breaks that occur each time the piece moves along the pss of the licrorelief.

For this purpose, it is necessary that the movement time of the part of a step is equal to the time of a complete revolution of the F of the grinding wheel around the X axis, that in the case where the machining is carried out using a single grinding wheel 1 (FIG. 11), or else it is equal to the rotation time of said axis F (FIG. 12) of an angle equal to the angle ss of disposition grinding wheels I adjacent, when the surface 2 is machined by several grinding wheels arranged at an equal distance about the axis M.

If the movement of the piece 3 has an intermittent character, the recess 4 (Figure 11) is presented, one section made by the plane of rotation of the grinding wheel 1, in the form of a circumference segment of center M and radius radius Ra which is the distance between the center M and the furthest point of said center, located on the cutting surface of the grinding wheel t.In the case of several grinding wheels,
Ra is the radius of the circumference described around said grinding wheels and passing through the points of their cutting surfaces furthest from their own axes of rotation.

When the surface 2 of the piece 3 is flat, the length S1 of the recess (FIG. 11) is the length of the circumferential cord of radius Ra mentioned and constitutes

Where Da = 2 Ra
h is the predetermined depth of the recess at
get, equal to the depth of cut.

où V3 est la vitesse moyenne d'avancement de la pièce 3
dans la direction indiquée par la flèche A
est le temps de rotation de l'axe F de la meule 1
autour de l'axe M d'un angle p (dans le cas
illustré sur la figure 11, ss est égal à 360*C);
To est le temps d'une révolution complète de l'axe F
de la meule 1 autour de l'axe M;
ZO est le nombre de meules participant à l'usinage
et disposées dans un même plan et à une distance
égale de l'axe M;;
ng est la vitesse de rotation de L'axe F de la meule 1
autour de l'axe M.The longitudinal step S (considered along arrow A) is then

where V3 is the average speed of advancement of part 3
in the direction indicated by arrow A
is the rotation time of the axis F of the grinding wheel 1
around the axis M of an angle p (in the case
illustrated in Figure 11, ss is 360 * C);
To is the time of a complete revolution of the F axis
grinding wheel 1 about the axis M;
ZO is the number of grinding wheels involved in machining
and arranged in the same plane and at a distance
equal to the axis M ;;
ng is the speed of rotation of the axis F of the grinding wheel 1
around the axis M.

 When the movement of the workpiece 3 in the direction indicated by the arrow A is continuous (FIGS. 12 and 13), the shape of the recess 4 is also close to that of a segment, but corresponds to a circumference of which the radius R2 is greater than the radius Ra.

 The length S1 of the recess then exceeds the length of the chord of the segment of radius Ra (as it would have been in the case of a stationary part) by a value depending on the speed V3 of the translation movement of the piece 3 in the direction indicated by the pin A and the time during which the piece 3 is in contact with the grinding wheel 1, which time corresponds to the rotation time of the axis F of said grinding wheel about the axis M of an angle yP determined by the arc of the mentioned segment.

The angle # / 2, practically equal to sin Y / 2, can be easily determined from the triangle given in FIG. 14, the triangle of which cdtd Ka is the half-chord of the radius segment Da: a

et la longueur S1 de l'évidement du microrelief constitue

It is obvious that the time tt, which is a part of the time of a complete revolution of the axis F of the grinding wheel 1 about the axis M, constitutes

and the length S1 of the recess of the microrelief constitutes

 Step S, considered in the direction indicated by the arrow A, is determined. as in the embodiment described above and providing an intermittent advancement of the part 3, according to the formula (11).

qui est analogue à la formule (8) pour le mode de réalisation du procédé caractérisé par un mouvement oscillatoire relatif.When the surface 2 to be treated is a surface of revolution (FIGS. 15 and 16), the part 3 is driven just as in the embodiments described above (providing for a periodic action of the grinding wheel on the part during their relative movement) , a rotation along the arrow A and an advance, while the axis M around which occurs the rotation of the axis F of the grinding wheel 1 is arranged parallel to the axis of rotation of the part 3 or well under a small angle that forms the angle 0 (elevation of the helical line along which are arranged the recesses 4 on the part 3 of the type considered r Figure 10) .The value of the angle Oc is determined then following formula (7). When the piece 3 in the form of a body of revolution (see FIG. 15) is in intermittent rotation (along the arrow A), the length 34 of the recess, taken along the common cord i has two circumferences, one of which is the diameter Da and the other of which has the diameter d of the part, can be determined using the formula

which is analogous to formula (8) for the embodiment of the method characterized by relative oscillatory motion.

ot n3 est la vitesse moyenne de rotation de la pièce.The angular pass # between the recesses of the microrelief is determined by starting from the equality of the rotation time of the piece i this step and the time t ss of revolution of the axis F around the axis M of an angle

ot n3 is the average speed of rotation of the part.

(ce qui découle de la formule connue, voir E.N. Maslov wOsnovy teorii shlifovania metallov", Mashgiz, M., 1951, p. 60, formule 35).In the case of a piece 3 in the form of a body of revolution driven by a continuous rotation movement (see FIG. 16), the length SiO of the diaper, measured along the circumference rope in section of the piece 3 by the plane of rotation of the grinding wheel 1, exceeds the length of a recess of the same depth, obtained on the piece 3 immobile, a value which is a function of the speed of rotation of the part 3 and the time during which it is in contact with the millstone 1, and can then be determined using the formula

(which follows from the known formula, see Maslov wOsnovy teorii shlifovania metallov ", Mashgiz, M., 1951, page 60, formula 35).

 As in the embodiment discussed above, the effect of the advancement of the workpiece on the dimensions of the microrelief is insignificant and therefore negligible.

 For the implementation of the method embodiments described above, where the periodic action of the tool on the surface to be machined is due to the rotation of the axis of the grinding wheel, it is the most rational to resort to a tool head 10 (see FIGS. 12, 17, 18, 19 and 20) in which the rotation is transmitted from the grinding machine spindle to the grinding wheels 1 according to the planetary principle of rotation transmission, which allows the movements to be shifted necessary with simple and compact mechanical means.

 The tool head 10 (see FIGS. 17 and 18) comprises a plate 11 intended to be fixed rigidly to the spindle 12 of the machine tool, a central pinion 13 permanently fixed to the frame and coaxial with the plate 11, as well as that planet gears 14 mounted around the periphery of the plate 11 and which, adapted for rotation, are meshing with the central gear 13. each of the planet gears 14 is connected rigidly, via a shaft 15 on which it is mounted to a grinding wheel 1. Thus, the speed n of rotation of each grinding wheel is equal to the speed of rotation of the respective planet gear 14 and the speed of rotation of the axis F of the wheel (see FIG. 12 ) is equal to the rotational speed of the plate 11. As is clear from Figure 18, which shows a constructional variant of the tool head 9 object of Figure 17, the tray It is made removable. The disassembly plane divides the plate 11 into a body 16 which, mounted on the body 17 of the spindle 12, is rotatable, and there is a disc 18 which, fixed on the spindle 12 with the help of a screw 19 and a washer 20, is connected to said body 16 via via 21.The central gear 13 and the planet gears 14 meshing with it are arranged in the cavity formed by the body 16 and the disc 18 of the plate 11, which which solves the problem of their lubrication.

A sealing part 22 provided in the space between the body 16 of the plate and the body 17 of the spindle 12 makes it possible to prevent any leakage of the oil from the aforementioned cavity of the plate 11. The central pinion 13 is permanently attached to the body 17 of the pin 12 with screws 23.

 The shafts 15 carrying the planet gears 14 and the grinding wheels 1, are rotatable in the body 16 and in the disc 18 of the plate 11 whose bosses serve as sliding supports for said shafts. It is possible to produce the tool head 10 according to a variant in which the only ones are arranged in several rows on the shafts 15, as shown, for example, in FIGS. 19 and 20. In the case under consideration, the wheels forming a row (that is to say, being in the same plane) are arranged with a shift, along a circumference, relative to the grinding wheels 1 forming the adjacent row, this to improve the dynamics of the operation of the head tool holder 10.

When the tool head is made in the manner just described, one of the wheels 1, is introduced into the surface layer of the workpiece being machined before the other one so . It is considered advantageous that the number of grinding wheels 1 in a row is not greater than 4. Otherwise, it is possible not to obtain separate recesses, since each grinding wheel 1 following occupy the portion of the surface layer (its length is designated S2 in the drawings (Figures 1116) between the recesses.To avoid this, it would have been necessary soft to reduce the circular speed of the grinding wheels 1, which would have a negative effect on the machining efficiency, or to increase the Da diameter of the tool head (figure 12, 17-20), which would have required more powerful machine tools and resulted in higher energy consumption.

 Operating experimentally, it has been established that, to obtain a microrelief, it is advisable to choose a tool head with a diameter Da of not less than 200 mm.

This value of the diameter Da makes it possible to have wheels 1 on the plate, the dimensions of which ensure them an optimal hold (not less than 25 minutes).

 To ensure the constancy of the profile of the recesses of the microrelief to be obtained, the edges of the cutting surface of each of the grinding wheels 1 are rounded with a radius ranging from 1 to 3 s. This avoids Dratique any change in the profile of the recesses during grinding wheels. These roundings also prevent the formation of small excrescences, under the effect of possible warping of the grinding wheels 1 with respect to the machining direction.

Examples 5-14
Uncoated carbon steel samples with a carbon content of 0.3-0.4% were tested and the samples were in the form of plates. The samples in question were installed in the device on a base connected kinamatically to a mechanism of displacement step by step. The device mentioned was then mounted on the table of a plane grinding machine whose spindle was provided with a tool head 10 (see FIGS. 17 and 18) comprising artificial corundum flat wheels 1 (96-ggX of Al 2 O 3). ) with a particle size of 160 to 200 m dispersed in a ceramic binder.

The diameter D of the grinding wheel was determined starting from the depth h of the microrelief to be obtained. The diameter Da of the tool head 10 was determined according to the nomogram given in FIG. 9 starting from the desired length S1 and the protonduct of the microrelief event.

The value obtained was rounded up to the values of the diameters Da of the prefabricated heads.

 The average speed V3 of translation movement of the sample was determined according to formula (11) starting from the speed n 0 of rotation of the plate 11 and the number o of grinding wheels t forming the tool head 10.

 Before machining, the tool head 10 has been adjusted for a depth of cut equal to the depth h of the microrelief.

 Each of the grinding wheels 1 acted on the surface of the sample during the breaks separating the displacements of the latter in the course of the microrelief step.

 Whenever a row of micrerelief was obtained over the entire length of the plate, the device was moved using the grinding machine table in the transverse direction at a distance equal to the value of the transverse pitch SO, and the operation was repeated.

 The results of the tests are shown in Table 1.

Table 1

<SEP> Dimension <SEP> of <SEP> Dimensions
<tb><SEP> sample <SEP> wanted <SEP> from <SEP> Tool
<tb><SEP> mierorelief, <SEP> mm
<tb><SEP> Of course
<tb><SEP> S1 <SEP> h <SEP> b <SEP> S <SEP> S0 <SEP> D <SEP> Z0 <SEP> r @ <SEP> Da <SEP> n0 <SEP> n
<tb><SEP> 1 <SEP> 2 <SEP> 3 <SEP> 4 <SEP> 5 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 10 <SEP> 11 <SEP> 12 <SEP> 13 <SEP> 14 <SEP> 15 <SEP> 16
<tb><SEP> 5 <SEP> 1 <SEP> 105 <SEP> 32 <SEP> 20 <SEP> 4 <SEP> 0.020 <SEP> 4 <SEP> 6 <SEP> 8 <SEP> 70 <SEP> 2 <SEP> 1 <SEP> 200 <SEP> 3000 <SEP> 6000
<tb><SEP> 6 <SEP> 2 <SEP> 153 <SEP> 45 <SEP> 25 <SEP> 5 <SEP> 0.025 <SEP> 5 <SEP> 7 <SEP> 10 <SEP> 70 <SEP> 2 <SEP> 1 <SEP> 250 <SEP> 2500 <SEP> 5000
<tb><SEP> 7 <SEP> 3 <SEP> 170 <SEP> 60 <SEP> 25 <SEP> 6 <SEP> 0.030 <SEP> 6 <SEP> 8 <SEP> 12 <SEP> 100 <SEP> 3 <SEP> 1 <SEP> 300 <SEP> 2000 <SEP> 4000
<tb><SEP> 8 <SEP> 4 <SEP> 150 <SEP> 60 <SEP> 25 <SEP> 8 <SEP> 0.040 <SEP> 8 <SEP> 10 <SEP> 16 <SEP> 150 <SEP> 3 <SEP> 1 <SEP> 400 <SEP> 1500 <SEP> 3000
<tb><SEP> 9 <SEP> 5 <SEP> 153 <SEP> 84 <SEP> 25 <SEP> 10 <SEP> 0.050 <SEP> 10 <SEP> 12 <SEP> 20 <SEP> 200 <SEP> 3 <SEP> 1 <SEP> 500 <SEP> 1100 <SEP> 2200
<tb><SEP> 10 <SEP> 6 <SEP> 270 <SEP> 60 <SEP> 25 <SEP> 11 <SEP> 0.060 <SEP> 11 <SEP> 14 <SEP> 22 <SEP> 200 <SEP> 4 <SEP> 1.5 <SEP> 500 <SEP> 800 <SEP> 1600
<tb><SEP> 11 <SEP> 7 <SEP> 380 <SEP> 90 <SEP> 30 <SEP> 13 <SEP> 0.070 <SEP> 13 <SEP> 17 <SEP> 26 <SEP> 250 <SEP> 4 <SEP> 1.5 <SEP> 600 <SEP> 700 <SEP> 1400
<tb><SEP> 12 <SEP> 8 <SEP> 315 <SEP> 90 <SEP> 30 <SEP> 16 <SEP> 0.080 <SEP> 16 <SEP> 20 <SEP> 32 <SEP> 500 <SEP> 3 <SEP> 1.5 <SEP> 800 <SEP> 650 <SEP> 1300
<tb><SEP> 13 <SEP> 9 <SEP> 415 <SEP> 90 <SEP> 30 <SEP> 19 <SEP> 0.090 <SEP> 19 <SEP> 26 <SEP> 38 <SEP> 400 <SEP> 3 <SEP> 1.5 <SEP> 1000 <SEP> 500 <SEP> 1000
<tb><SEP> 14 <SEP> 10 <SEP> 415 <SEP> 90 <SEP> 35 <SEP> 22 <SEP> 0.100 <SEP> 22 <SEP> 50 <SEP> 40 <SEP> 500 <SEP><SEP> 1.5 <SEP> 1200 <SEP> 450 <SEP> 900
<tb> Table 1 (continued)

<SEP> Dimensions <SEP> obtained <SEP> from
<tb><SEP> microrelief, <SEP> mm
<tb><SEP> V3 <SEP> S1 <SEP> h <SEP> b <SEP> S <SEP> S0
<tb><SEP> 1 <SEP> 17 <SEP> 18 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 5 <SEP> 36 <SEP> 10 <SEP> 4.1 <SEP> 0.020 <SEP> 4.0 <SEP> 6.0 <SEP> 8.0
<tb><SEP> 6 <SEP> 35 <SEP> 17 <SEP> 5.0 <SEP> 0.026 <SEP> 5.0 <SEP> 7.1 <SEP> 10.0
<tb><SEP> 7 <SEP> 48 <SEP> 14 <SEP> 5.9 <SEP> 0.030 <SEP> 6.0 <SEP> 8.0 <SEP> 12.0
<tb><SEP> 8 <SEP> 45 <SEP> 14 <SEP> 8.0 <SEP> 0.039 <SEP> 8.0 <SEP> 9.9 <SEP> 16.0
<tb><SEP> 9 <SEP> 39.6 <SEP> 16 <SEP> 10.0 <SEP> 0.050 <SEP> 10.0 <SEP> 12.0 <SEP> 20.0
<tb><SEP> 10 <SEP> 44.8 <SEP> 10 <SEP> 10.9 <SEP> 0.061 <SEP> 11.0 <SEP> 13.9 <SEP> 22.0
<tb><SEP> 11 <SEP> 47.6 <SEP> 14 <SEP> 13.0 <SEP> 0.069 <SEP> 13.1 <SEP> 17.1 <SEP> 26.0
<tb><SEP> 12 <SEP> 39 <SEP> 14 <SEP> 16.2 <SEP> 0.080 <SEP> 16.0 <SEP> 20.0 <SEP> 32.0
<tb><SEP> 13 <SEP> 39 <SEP> 10 <SEP> 19.3 <SEP> 0.090 <SEP> 19.1 <SEP> 25.9 <SEP> 38.0
<tb><SEP> 14 <SEP> 40.5 <SEP> 16 <SEP> 22.2 <SEP> 0.100 <SEP> 22.1 <SEP> 30.2 <SE> 40.1
<Tb>
As can be seen from the table given above, in all cases the microrelief obtained was in accordance with the predetermined dimensions, with sufficient precision for practical needs. No outgrowth or burr was reported on the surfaces between the recesses.

Examples 15-24
Tests were made of 0.12 "carbon-nickel steel samples with a superficial hardness of 60 HRC, samples numbered 11 to 20 were in the form of a plate whose dimensions, as were the predefined dimensions of the microrelief to be obtained, were similar to the respective parameters of samples 1 to 10 of Examples 5-14.

 The machining of the samples was carried out as described in the previous examples and using similar equipment and tooling.

The dimensions of the microrelief obtained on each of samples II to 20 are shown in Table 2 below,
Table 2

<tb> N <SEP> Type <SEP> Dimensions <SEP> Obtained
<tb><SEP> of <SEP> of the <SEP> microrelief <SEP>. <September>
<Tb>

@ <SEP> tillon <SEP><SEP> Evidently <SEP> Not <SEP> Not
<tb> ple <SEP> lon- <SEP> Profon- <SEP> lar- <SEP> Long- <SEP> trans
<tb> @@@@@ <SEP> deu @ <SEP> @@@@ <SEP> tudi- <SEP> versal
<tb><SEP><SEP><SEP><SEP>
<tb><SEP> h <SEP> S1 <SEP> h <SEP> b <SEP> S
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> -21 <SEP> 22 <SEP> 23
<tb> 15 <SEP> It <SEP> 4.0 <SEP> 0.020 <SEP> 4.0 <SEP> 6.1 <SEP> 8.0
<tb> 16 <SEP> 12 <SEP> 5.1 <SEP> 0.025 <SEP> 5.0 <SEP> 7.0 <SEP> 10.0
<tb> 17 <SEP> 13 <SEP> 5.9 <SEP> 0.030 <SEP> 6.0 <SEP> 8.0 <SEP> 12.0
<tb> 18 <SEP> 14 <SEP> 8.0 <SEP> 0.040 <SEP> 8.0 <SEP> 10.0 <SEP> 16.1
<tb> 19 <SEP> 15 <SEP> 10.0 <SEP> 0.050 <SEP> 10.0 <SEP> 12.1 <SEP> 20.0
<tb> 20 <SEP> 16 <SEP> 11.0 <SEP> 0.061 <SEP> 11.0 <SEP> 13.9 <SEP> 22.0
<Tb>
Table 2 (continued)

<tb> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP>#<SEP> 22 <SEP>#<SEP> 23
<tb> 21 <SEP> 17 <SEP> 12.9 <SEP> 0.070 <SEP> 13.00 <SEP> 17.0 <SEP> 25.9
<tb> 22 <SEP> 18 <SEP> 16.0 <SEP> 0.079 <SEP> 16.1 <SEP> 20.1 <SEP> 32.0
<tb> 23 <SEP> 19 <SEP> 19.1 <SEP> 0.091 <SEP> 19.0 <SEP> 26.0 <SEP> 38.0
<tb> 24 <SEP> 20 <SEP> 22.0 <SEP> 0.099 <SEP> 22.0 <SEP> 30.0 <SEP> 40.0
<Tb>
The difference between the dimensions obtained and those that had been predicted was within the allowed deviation of + 5%, the surface of the samples, between the recesses, had no protruding or smearing.

Exeinles 25-34
The operating conditions, equipment and dimensions of samples 21 to 30 subjected to machining were similar to those shown in Examples 5 to 14. The material of the samples in question was a tin and fluorine bronze of which the hardness was 160 HB. The flat grinding wheels 1 forming the tool head 10 (see FIGS. 17 and 18) were made of black silicon carbide (more than 95% SiC), with a particle size of 160-200 m, dispersed in a ceramic binder.

 Microreliefs were obtained whose dimensions for each of the samples 21 to 30 are shown in Table 3 below.

Table 3

N <SEP> Type <SEP><SEP> dimensions obtained <SEP> of <SEP> microrelief,
<tb><SEP> of exchange <SEP> n <SEP>
<tb><SEP> exem- <SEP> tillon <SEP> Evidently <SEP> Not <SEP> Not
<tb> ple
<tb><SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP> longitu- <SEP> trans
<tb><SEP> deur <SEP> geur <SEP> dinal <SEP> versal
<tb> h <SEP> h <SEP> b <SEP> S
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 25 <SEP> 21 <SEP> 4.0 <SEP> 0.020 <SEP> 4.0 <SEP> 6.0 <SEP> 8.0
<tb><SEP> 26 <SEP> 22 <SEP> 5.0 <SEP> 0.025 <SEP> 5.0 <SEP> 7.0 <SEP> 10.0
<Tb>
Table 3 (continued)

<tb> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb> 27 <SEP> 23 <SEP> 6.0 <SEP> 0.031 <SEP> 6.0 <SEP> 8, where <SEP> 12.1
<tb> 28 <SEP> 24 <SEP> 7.9 <SEP> 0.040 <SEP> 8.0 <SEP> 10.1 <SEP> 16.0
<tb> 29 <SEP> 25 <SEP> 10.0 <SEP> 0.050 <SEP> 10.0 <SEP> 11.9 <SEP> 20.0
<tb> 30 <SEP> 26 <SEP> 11.0 <SEP> 0.060 <SEP> 11.1 <SEP> 14.0 <SEP> 22.0
<tb> 31 <SEP> 27 <SEP> 13.0 <SEP> 0.070 <SEP> 13.0 <SEP> 17.0 <SEP> 26.0
<tb> 32 <SEP> 28 <SEP> 16.1 <SEP> 0.079 <SEP> 16.0 <SEP> 20.0 <SEP> 31.9
<tb> 33 <SEP> 29 <SEP> 19.0 <SEP> 0.089 <SEP> 19.0 <SEP> 25.9 <SEP> 38.0
<tb> 34 <SEP> 30 <SEP> 22.0 <SEP> 0.100 <SEP> 22.1 <SEP> 30.1 <SEP> 40.0
<Tb>
The difference between the dimensions obtained and those which had been predicted was within the limits of the accepted difference. No outgrowth or burr was reported on the surface of the samples.

zxolDles 35-44
The operating conditions, equipment and dimensions of samples 31 to 40 were similar to those in Examples 5-14. The material of the samples in question was a quenched nickelchrome slit with a surface hardness of 675 HB.

 The tool head 10 (FIGS. 17 and 18) was made up of flat grinding wheels 1 of green silicon carbide (more than 97% SiC> SiC) with a particle size of 160-200 m dispersed in a ceramic binder.

 Miororeliefs were obtained whose dimensions for each of the samples from 31 to 40 are shown in Table 4.

Table 4

<tb> N <SEP> Type <SEP><SEP> Sizes <SEP> obtained from <SEP> microrelief
<tb><SEP> of sample <SEP> mm
<tb> exem- <SEP> tillon <SEP> Evidly <SEP> Not <SEP> Not
<tb><SEP> ple <SEP> Lon- <SEP> Profon- <SEP> Lar- <SE> longitu- <SEP> trans
<tb><SEP><SEP> seur <SEP> geur <SEP> dinal <SEP> versal
<tb><SEP> S1 <SEP> h <SEP> b <SEP> S <SEP> S0
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb> 35 <SEP> 31 <SEP> 3.9 <SEP> 0.020 <SEP> 4.0 <SEP> 6.1 <SEP> 8.0
<tb> 36 <SEP> 32 <SEP> 5.0 <SEP> 0.025 <SEP> 5.0 <SEP> 7.0 <SEP> 10.0
<tb> 37 <SEP> 33 <SEP> 6.1 <SEP> 0.030 <SEP> 6.0 <SEP> 8.1 <SEP> 12.0
<tb> 38 <SEP> 34 <SEP> 8.0 <SEP> 0.040 <SEP> 8.0 <SEP> 9.9 <SEP> 16.2
<tb> 39 <SEP> 35 <SEP> 10.1 <SEP> 0.051 <SEP> 10.0 <SEP> 12.0 <SEP> 20.0
<tb> 40 <SEP> 36 <SEP> 11.0 <SEP> 0.060 <SEP> 11.0 <SEP> 14.0 <SEP> 22.0
<tb> 41 <SEP> 37 <SEP> 13.1 <SEP> 0.069 <SEP> 13.1 <SEP> 17.1 <SEP> 25.9
<tb> 42 <SEP> 38 <SEP> 16.0 <SEP> 0.080 <SEP> 15.9 <SEP> 20.0 <SEP> 32.0
<tb> 43 <SEP> 39 <SEP> 19.0 <SEP> 0.090 <SEP> 19.0 <SEP> 25.9 <SEP> 38.0
<tb> 44 <SEP> 40 <SEP> 21.9 <SEP> 0.110 <SEP> 22.0 <SEP> 30.0 <SEP> 40.0
<Tb>
The difference between the dimensions obtained and those which had been planned was within the limits of the allowed gap. The surface between the recesses corresponded to the initial surface.

Examples 45-54
Uncoated carbon steel samples with a carbon content of 0.3-0.4% were tested and the samples were cylindrical in shape. The samples in question were fixed between the tips of a device equipped with an inter-stationary rotation mechanism. The device mentioned was mounted on the table of a plane grinding machine whose spindle carried a tool head 10 (see FIGS. 17 and 18) provided with flat grinding wheels 1 made of white artificial corundum (96-99% Al 2 O 3) to granulometry of 160-200 8m dispersed in a ceramic binder. The diameter D of the grinding wheels 1 was chosen as a function of the depth of cut. The diameter Da of the tool head 10 was determined using the formula (15), the value obtained then being rounded up to Da values of prefabricated heads killed. The speed n3 of rotation of the sample was calculated according to the formula (16) starting from the value ng of the speed of rotation of the plate 11 and the number ZO of grinding wheels 1 united in the tool head 10.

 Prior to machining, the tool head 10 was adjusted to a depth of cut equal to the depth h of the microrelief.

 Each of the grinding wheels 1 acted on the surface of the sample during the breaks intervening between its displacements of a step d. For all samples the # step was 6d. The progress of the sample was carried out continuously using the table of the grinding machine. The results of the tests are shown in Table 5.

Table 5

<SEP> Dimensions <SEP> Predetermined <SEP> Dimensions
<tb><SEP> of <SEP> the <SEP> sample of <SEP> miororelief <SEP> Tool
<tb><SEP> tillen, <SEP> mm
<tb><SEP> Of course
<tb><SEP> 1 <SEP> 2 <SEP> 3 <SEP> 4 <SEP> 5 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 10 <SEP> 11 <SEP> 12 <SEP> 13 <SEP> 14 <SEP> 15
<tb><SEP> 45 <SEP> 41 <SEP> 75 <SEP> 200 <SEP> 2.0 <SEP> 0.020 <SEP> 2.0 <SEP> 100 <SEP> 4.0 <SEP> 70 <SEP> 4 <SEP> 1.0 <SEP> 200 <SEP> 3000 <SEP> 6000
<tb><SEP> 46 <SEP> 42 <SEP> 100 <SEP> 200 <SEP> 3.0 <SEP> 0.030 <SEP> 3.0 <SEP> 1 10 '<SEP> 5.0 <SEP> 100 <SEP> 4 <SEP> 1.0 <SEP> 300 <SEP> 2200 <SEP> 5500
<tb><SEP> 47 <SEP> 43 <SEP> 130 <SEP> 200 <SEP> 4.0 <SEP> 0.040 <SEP> 4.0 <SEP> 1 10 '<SEP> 6.25 <SEP> 150 <SEP> 4 <SEP> 1.5 <SEP> 400 <SEP> 2000 <SEP> 4000
<tb><SEP> 48 <SEP> 44 <SEP> 170 <SEP> 300 <SEP> 5.0 <SEP> 0.050 <SEP> 5.0 <SEP> 1 10 '<SEP> 8.36 <SEP> 200 <SEP> 4 <SEP> 1.5 <SEP> 500 <SEP> 1500 <SEP> 3500
<tb><SEP> 49 <SEP> 45 <SEP> 200 <SEP> 300 <SEP> 6.0 <SEP> 0.060 <SEP> 6.0 <SEP> 1 10 '<SEW> 10.43 <SEP> 250 <SEP> 4 <SEP> 1.5 <SEP> 600 <SEP> 1100 <SEP> 2200
<tb><SEP> 50 <SEP> 46 <SEP> 230 <SEP> 300 <SEP> 7.0 <SEP> 0.070 <SEP> 7.0 <SEP> 1 10 '<SEW> 11.90 <SEP> 300 <SEP> 4 <SEP> 1.5 <SEP> 700 <SEP> 800 <SEP> 1600
<tb><SEP> 51 <SEP> 47 <SEP> 270 <SEP> 300 <SEP> 8.0 <SEP> 0.080 <SEP> 8.0 <SEP> 1 10 '<SEW> 13.88 <SEP> 300 <SEP> 4 <SEP> 1.5 <SEP> 800 <SEP> 700 <SEP> 1400
<tb><SEP> 52 <SEP> 48 <SEP> 300 <SEP> 350 <SEP> 9.0 <SEP> 0.090 <SEP> 9.0 <SEP> 1 10 '<SEW> 15.58 <SEP> 350 <SEP> 4 <SEP> 1.5 <SEP> 900 <SEP> 650 <SEP> 1300
<tb><SEP> 53 <SEP> 49 <SEP> 330 <SEP> 350 <SEP> 10.0 <SEP> 0.100 <SEP> 10.0 <SEP> 1 10 '<SEW> 17.13 <SEP> 400 <SEP> 4 <SEP> 1.5 <SEP> 1000 <SEP> 500 <SEP> 1000
<tb><SEP> 54 <SEP> 50 <SEP> 400 <SEP> 400 <SEP> 11.0 <SEP> 0.100 <SEP> 11.0 <SEP> 100 <SEP> 20.93 <SEP> 500 <SEP> 14 <SEP> 1.5 <SEP> 1200 <SEP> 450 <SEP> 900
<tb> Table 5 (continued)

<SEP> Dimensions <SEP> obtained
<tb><SEP> of the <SEP> microrelief
<tb><SEP> S1 <SEP> h <SEP> b <SEP>&alpha;<SEP> S
<tb><SEP> 1 <SEP> 16 <SEP> 17 <SEP> 18 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb> 45 <SEP> 200 <SEP> 4 <SEP> 10 <SEP> 2.1 <SEP> 0.020 <SEP> 2.0 <SEP> 100 <SEP> 4.0
<tb> 46 <SEP> 160 <SEP> 6 <SEP> 11 <SEP> 3.0 <SEP> 0.030 <SEP> 3.0 <SEP> 1 10 <SEP> 5.0
<tb> 47 <SEP> 123 <SEP> 8 <SEP> 12 <SEP> 4.0 <SEP> 0.040 <SEP> 4.0 <SEP> 1 10 '<SEP> 6.3
<tb> 48 <SEP> 100 <SEP> 10 <SEP> 13 <SEP> 4.9 <SEP> 0.050 <SEP> 5.0 <SEP> 1 10 '<SEP> 8.4
<tb> 49 <SEP> 73 <SEP> 12 <SEP> 14 <SEP> 6.0 <SEP> 0.060 <SEP> 6.0 <SEP> 1 10 <SEP> 10.5
<tb> 50 <SEP> 53 <SEP> 14 <SEP> 15 <SEP> 7.1 <SEP> 0.070 <SEP> 7.0 <SEP> 1 10 <SEP> 12.0
<tb> 51 <SEP> 46 <SEP> 16 <SEP> 16 <SEP> 7.9 <SEP> 0.080 <SEP> 8.0 <SEP> 1 10 '<SEP> 13.9
<tb> 52 <SEP> 43 <SEP> 18 <SEP> 17 <SEP> 9.0 <SEP> 0.090 <SEP> 9.0 <SEP> 1 10 <SEP> 15.6
<tb> 53 <SEP> 33 <SEP> 20 <SEP> 18 <SEP> 10.0 <SEP> 0.100 <SEP> 10.0 <SEP> 1 10 <SEP> 17.2
<tb> 54 <SEP> 30 <SEP> 22 <SEP> 19 <SEP> 11.1 <SEP> 0.100 <SEP> 11.0 <SEP> 100 <SEP> 21.0
<Tb>
As can be seen from Table 5, the difference between the dimensions obtained and those provided did not exceed the 5% allowed. no outgrowth or burr was reported on the surface of the sample between the recesses.

Examples 55-64
The 0.12% carbon-nickel steel samples with a hardness of 60 HRC were tested. The samples had a cylindrical shape. The dimensions of the samples 51 to 60, as well as the predetermined dimensions of the microrelief were similar to those shown in Examples 45-54.

 The machining is performed as described in Examples 45-54 using similar equipment and tooling. The tool and sample movement parameters 51-60 were as shown in Table 5 for samples 41-50.

 The dimensions of the microreliefs obtained for each of the samples 51-60 are combined in Table 6.

Table 6

<tb> N <SEP> of exem- <SEP> Type <SEP> SEP <SEP> dimensions obtained <SEP> of <SEP>
<tb> ple <SEP> of eccn- <SEP> relief
<tb><SEP> tillon
<tb><SEP> Evidently <SEP> Angle <SEP> Not
<tb><SEP> of elevation <SEP> circu
<tb><SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP><SEP> of <SEP>
<tb><SEP>,<SEP> line, <SEP> geur, <SEP> the <SEP> line
<tb><SEP> n <SEP> n <SEP> n <SEP> helico- <SEP> IF <SEP>
<tb><SEP> dale
<tb><SEP> h <SEP> b <SEP> n <SEP>
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 2
<tb><SEP> 55 <SEP> 51 <SEP> 2.1 <SEP> 0.02 <SEP> 2.0 <SEP> 1t00 '<SEP> 3.9
<tb><SEP> 56 <SEP> 52 <SEP> 3.0 <SEP> 0.03 <SEP> 3.0 <SEP> 10101 <SEW> 5.0 <SEP>
<tb><SEP> 57 <SEP> 53 <SEP> 4.0 <SEP> 0.04 <SEP> 4.0 <SEP> 1.10 '<SEP> 6.3
<tb><SEP> 58 <SEP> 54 <SEP> 4.9 <SEP> 0.05 <SEP> 5.0 <SEP> 1.11 '<SEP> 8.3
<Tb>
Table 6 (continued)

<SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 59 <SEP> 55 <SEP> 6.1 <SEP> 0.06 <SEP> 6.0 <SEP> 1 10 <SEP> 10.4
<tb> 60 <SEP> 56 <SEP> 7.1 <SEP> 0.07 <SEP> 6.9 <SEP> 1 10 '<SEP> 11.9
<tb> 61 <SEP> 57 <SEP> 7.9 <SEP> 0.08 <SEP> 8.0 <SEP> 1 09 '<SEP> 13.9
<tb> 62 <SEP> 58 <SEP> 9.1 <SEP> 0.09 <SEP> 9.0 <SEP> 1 10 '<SEP> 15.6
<tb> 63 <SEP> 59 <SEP> 10.1 <SEP> 0.10 <SEP> 10.0 <SEP> 1 10 '<SEP> 17.1
<tb> 64 <SEP> 60 <SEP> 11.1 <SEP> 0.10 <SEP> 11.0 <SEP> 100 <SEP> 21.0
<Tb>
The difference between the dimensions obtained and those provided did not exceed the 5% allowed. No outgrowth or burr was reported on the surface of the samples between recesses.

Examples 65-74
The operating conditions, equipment and dimensions of samples 61-70 were similar to those of Examples 45-54. The samples mentioned were made of tin-fluorine bronze and had a hardness of 160 HB. The tool head 10 was otmie flat grinding wheels 1 (see Figures 17 and 18) black silicon carotid (more than 95% SiC) particle size of 160-200 m, dispersed in a ceramic binder.

 Microrellets were obtained, the dimensions of which for each of the samples 61-70 are combined in Table 7.

Table 7

<tb><SEP> N <SEP><SEP> Type <SEP> Dimensions Obtained <SEP> From <SEP> Microrelie
<tb><SEP> of exem- <SEP> of exchange
<tb> ple <SEP> tillon <SEP> Evidently <SEP> An <SEP> on <SEP> Not
<tb><SEP> of elevation <SEP> circu
<tb><SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP><SEP> of <SEP>
<tb><SEP>,<SEP> line, <SEP> geun <SEP> the <SEP> line
<tb><SEP> mm <SEP> mm <SEP> mm <SEP> helical- <SEP> S <SEP> = <SEP># d # / 360
<tb><SEP> dale
<tb> S1 <SEP> h <SEP> b <SEP>&alpha;<SEP><SEP><SEP> mm
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 65 <SEP> 61 <SEP> 2.1 <SEP> 0.02 <SEP> 2.0 <SEP> 1.00 <SEP> 3.99
<tb><SEP> 66 <SEP> 62 <SEP> 3.0 <SEP> 0.03 <SEP> 3.0 <SEP> 1 10 '<SEP> 5.0
<tb><SEP> 67 <SEP> 63 <SEP> 4.0 <SEP> 0.04 <SEP> 4.1 <SEP> 1 10 '<SEP> 6.1
<tb><SEP> 68 <SEP> 64 <SEP> 5.0 <SEP> 0.05 <SEP> 5.0 <SEP> 1 10 '<SEP> 8.4
<tb><SEP> 69 <SEP> 65 <SEP> 6.1 <SEP> 0.06 <SEP> 6.0 <SEP> 1-10 <SEP> 10.4
<tb><SEP> 70 <SEP> 66 <SEP> 7.2 <SEP> 0.07 <SEP> 7.0 <SEP> 1 10 '<SEP> 11.8
<tb><SEP> 71 <SEP> 67 <SEP> 8.0 <SEP> 0.08 <SEP> 8.0 <SEP> 1 10 <SEP> 13.9
<tb><SEP> 72 <SEP> 68 <SEP> 9.1 <SEP> 0.09 <SEP> 9.2 <SEP> 1 10 '<SEW> 15.6
<tb><SEP> 73 <SEP> 69 <SEP> 9.9 <SEP> 0.10 <SEP> 10.0 <SEP> 1.10 '<SEP> 17.2
<tb><SEP> 74 <SEP> 70 <SEP> 11.0 <SEP> 0.10 <SEP> 11.1 <SEP> 1 00 '<SEP> 20.9
<Tb>
The difference between the dimensions obtained and those predicted was within the limits of the allowed deviation. No outgrowth or burr was reported on the surface of the samples.

Examples 75-84
The operating conditions, equipment and dimensions of the samples tested were similar to those of Examples 45-54. The sample material was a hardened nickel-chromium cast iron with a surface hardness of 675 HB.

 The tool head 10 (see Figures 17 and 18) was provided with flat grinding wheels 1 of green silicon carbide (more than 97% SiC) with a particle size of 160-200 m dispersed in a ceramic binder. Microreliefs were obtained, the dimensions of which for each of the samples are shown in Table 8.

Table 8

<SEP> N <SEP> Type <SEP> Dimensions <SEP> obtained <SEP> from <SEP> microrelief
<tb><SEP> of exem- <SEP> of exchange
<tb><SEP> ple <SEP> tillon <SEP> Evidently <SEP> Angle <SEP> No <SEP> oir
<tb><SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP> of elevation <SEP>
<tb><SEP>,<SEP>,<SEP> geur, <SEP> tion <SEP> of
<tb><SEP> mm <SEP> mm <SEP> mm <SEP> The <SEP> line <SEP> S <SEP> = <SEP># d # / 360
<tb><SEP> S1 <SEP> h <SEP> b <SEP>&alpha;<SEP><SEP> mm
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 75 <SEP> 71 <SEP> 1.9 <SEP> 0.02 <SEP> 2.0 <SEP> 100 <SEP> 4.0
<tb><SEP> 76 <SEP> 72 <SEP> 3.1 <SEP> 0.03 <SEP> 3.0 <SEP> 1 10 '<SEP> 5.0
<tb><SEP> 77 <SEP> 73 <SEP> 4.8 <SEP> 0.04 <SEP> 4.0 <SEP> 1 10 <SEP> 6.2
<tb><SEP> 78 <SEP> 74 <SEP> 4.9 <SEP> 0.05 <SEP> 5.0 <SEP> 1 10 '<SEP> 8.4
<tb><SEP> 79 <SEP> 75 <SEP> 6.0 <SEP> 0.06 <SEP> 6.0 <SEP> 1 10 <SEP> 10.4
<tb><SEP> 80 <SEP> 76 <SEP> 7.1 <SEP> 0.07 <SEP> 7.0 <SEP> 1.101 <SEP> 12.0
<tb><SEP> 81 <SEP> 77 <SEP> 8.1 <SEP> 0.0. <SEP> 8.1 <SEP> 1 10 '<SEP> 13.8
<tb><SEP> 82 <SEP> 78 <SEP> 8.9 <SEP> 0.09 <SEP> g, <SEP> 1 10 <SEP> 15.7
<tb><SEP> 83 <SEP> 79 <SEP> 10.0 <SEP> o, <SEP> 10 <SEP> 10.0 <SEP> 1 10 '<SEP> 17.1
<tb><SEP> 84 <SEP> 80 <SEP> 11.1 <SEP> 0.10 <SEP> 11.0 <SEP> 100 <SEP> 20.9
<Tb>
The difference between the dimensions obtained and those predicted was within the limits of the allowed deviation. He did not report any outgrowth or burr on the surface of the samples between the recesses.

Examples 85-94
Samples of types 1-10 described in Examples 5-14 were placed on the table of a planar grinding machine whose spindle bore a head 10 (see Figures 17 and 18).

 Before machining, the tool head 10 has been adjusted to a depth of cut equal to the depth h of the microrelief to obtain. The head 10 was rotated about the axis M and the table of the grinding machine, a translation movement at a speed V3 in the opposite direction to that of rotation. After choosing the speed V3 of continuous displacement of the table, the speed n0 of rotation of the plate and the vitesee n of rotation of the grinding wheel, as they appear in Table 1, we determined the values of the elements of the microrelief which The other elements of the microrelief and test parameters were similar to those shown in Table 1. The results of the calculations and tests are summarized in Table 9 (the columns). Table 9 verticals are numbered in accordance with the numbering adopted for Table 1).

Table 9

<tb><SEP> Predicted <SEP> Dimensions <SEP> Calculated <SEP> Dimensions
<tb> Type <SEP> of <SEP> microrelief, <SEP> mm <SEP> of <SEP> microrelief, <SEP> mm
<tb> of exchange
<tb> esem- <SEP> tillon <SEP> Profon- <SEP> Lar- <SEP> Not <SEP> Lon- <SEP> Not <SEP> longi
<tb> ple <SEP> deur <SEP> geur <SEP> trans- <SEP> si <SEP> tudinal
<tb><SEP> versal
<tb><SEP> h <SEP> b <SEP> S0 <SEP> S1 <SEP> S
<tb><SEP> 1 <SEP> 2 <SEP> 7 <SEP> 8 <SEP> 10 <SEP> 6 <SEP> 9
<tb><SEP> 85 <SEP> 1 <SEP> 0.020 <SEP> 4 <SEP> 8 <SEP> 4.1 <SEP> 6
<tb><SEP> 86 <SEP> 2 <SEP> 0.025 <SEP> 5 <SEP> 10 <SEP> 5.1 <SEP> 7
<tb><SEP> 87 <SEP> 3 <SEP> 0.030 <SEP> 6 <SEP> 12 <SEP> 6.1 <SEP> 8
<tb><SEP> 88 <SEP> 4 <SEP> 0.040 <SEP> 8 <SEP> 16 <SEP> 8.1 <SEP> 10
<tb><SEP> 89 <SEP> 5 <SEP> 0.050 <SEP> 10 <SEP> 20 <SEP> 10.1 <SEP> 12
<tb><SEP> 90 <SEP> 6 <SEP> 0.060 <SEP> It <SEP> 22 <SEP> 11.2 <SEP> 14
<tb><SEP> 91 <SEP> 7 <SEP> 0.070 <SEP> 13 <SEP> 26 <SEP> 13.3 <SEP> 17
<tb><SEP> 92 <SEP> 8 <SEP> 0.080 <SEP> 16 <SEP> 32 <SEP> 16.4 <SEP> 20
<tb><SEP> 93 <SEP> 9 <SEP> 0.090 <SEP> 19 <SEP> 38 <SEP> 19.5 <SEP> 26
<tb><SEP> 94 <SEP> 10 <SEP> 0.100 <SEP> 22 <SEP> 40 <SEP> 22.5 <SEP> 30
<Tb>
Table 9 (continued)

<tb> N <SEP><SEP> dimensions obtained <SEP> of <SEP> microrelief,
<tb> d1exem- <SEP> mm
<tb> pie
<tb><SEP> S1 <SEP> h <SEP> h <SEP> b <SEP> S
<tb> 1 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 85 <SEP> 4.1 <SEP> 0.020 <SEP> 4.0 <SEP> 6.0 <SEP> 8.0
<tb><SEP> 86 <SEP> 5.2 <SEP> 0.025 <SEP> 5.0 <SEP> 7.0 <SEP> 10.0
<tb><SEP> 87 <SEP> 6.1 <SEP> 0.030 <SEP> 6.0 <SEP> 8.1 <SEP> 12.0
<tb><SEP> 88 <SEP> 8.2 <SEP> 0.040 <SEP> 8.0 <SEP> 10.0 <SEP> 16.0
<tb><SEP> 89 <SEP> 10.1 <SEP> 0.050 <SEP> 10.1 <SEP> 12.0 <SEP> 20.0
<tb><SEP> 90 <SEP> 11.2 <SEP> 0.060 <SEP> 11.0 <SEP> 13.9 <SEP> 22.0
<tb><SEP> 91 <SEP> 13.4 <SEP> 0.070 <SEP> 13.0 <SEP> 17.0 <SEP> 26.1
<tb><SEP> 92 <SEP> 16.4 <SEP> 0.080 <SEP> 16.0 <SEP> 20.2 <SEP> 32.0
<tb><SEP> 93 <SEP> 20.0 <SEP> 0.090 <SEP> 19.0 <SEP> 26.1 <SEP> 38.0
<tb><SEP> 94 <SEP> 22.4 <SEP> 0.100 <SEP> 22.0 <SEP> 30.3 <SEP> 40.4
<Tb>
The difference between the dimensions obtained and those predicted was within the limits of the allowed deviation. No growth or burr was reported on the surface of the sample.

Examples 95-104
Samples of types 11-20 were machined using grinding wheels similar to those of Examples 15-24, which machining was carried out as described in Examples 95-94. Microreliefs were obtained, the dimensions of which for each of the samples are shown in Table 10.

Table 10

<tb> N <SEP> Type <SEP> Resulted <SEP><SEP> dimensions of <SEP> microrelief,
<tb><SEP> of sample <SEP> mm
<tb> exem- <SEP> tillon
<tb> ple <SEP> Evidently <SEP> Not <SEP> Not
<tb><SEP> long- <SEP> trans
<tb><SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP> tudinal <SEP> versal
<tb><SEP><SEP><SEP>
<tb><SEP> S <SEP> h <SEP> b <SEP> S
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 95 <SEP> It <SEP> 4.1 <SEP> 0.020 <SEP> 4.1 <SEP> 6.0 <SEP> 8
<tb><SEP> 95 <SEP> 12 <SEP> 5.1 <SEP> 0.025 <SEP> 5.0 <SEP> 7.0 <SEP> 10.0
<tb><SEP> 97 <SEP> 13 <SEP> 6.1 <SEP> 0.030 <SEP> 6.0 <SEP> 8.1 <SEP> 12.0
<tb><SEP> 98 <SEP> 14 <SEP> 8.2 <SEP> 0.040 <SEP> 7.9 <SEP> 10.1 <SEP> 16.3
<tb><SEP> 99 <SEP> 15 <SEP> 10.1 <SEP> 0.05C <SEP> 10.0 <SEP> 12.0 <SEP> 20.1
<tb> 100 <SEP> 16 <SEP> 11.1 <SEP> 0.060 <SEP> 11.0 <SEP> 14.1 <SEP> 22.0
<tb> 101 <SEP> 17 <SEP> 13.5 <SEP> 0.070 <SEP> 13.0 <SEP> 17.0 <SEP> 26.0
<tb> 102 <SEP> 18 <SEP> 16.5 <SEP> 0.080 <SEP> 16.1 <SEP> 20.1 <SEP> 32.0
<tb> 103 <SEP> 19 <SEP> 20.1 <SEP> 0.090 <SEP> 19.0 <SEP> 26.1 <SEP> 38.0
<tb> 104 <SEP> 20 <SEP> 22.3 <SEP> 0.100 <SEP> 22.0 <SEP> 30.0 <SEP> 40.2
<Tb>
The difference between the dimensions obtained and those which were planned did not exceed + 5 *. The surface between the recesses showed no protuberance or burr.

Examples 105-114
Type 21-30 samples were machined with wheels similar to those of Examples 25-34 and as described in Examples 85-94.

Micro-reliefs were obtained whose dimensions for each of the samples are shown in Table 11.

Table II

<tb><SEP><SEP> SEP <SEP> dimensions obtained from <SEP> microrelief, <SEP>
<tb> N <SEP> Type <SEP> mm
<tb><SEP> of exchange <SEP> Evidence <SEP> Fas <SEP> No
<tb> exem- <SEP> tillon <SEP> long- <SEP> trans
<tb> ple <SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP> tudinal <SEP> versal
<tb><SEP><SEP><SEP>
<tb><SEP> h <SEP> b <SEP> 50 <SEP>
<tb><SEP> 1 <SEP>#<SEP><SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb> 105 <SEP> 21 <SEP> 4.1 <SEP> 0.020 <SEP> 4.0 <SEP> 6.1 <SEP> 8.0
<tb> 106 <SEP> 22 <SEP> 5.1 <SEP> 0.025 <SEP> 5.0 <SEP> 7.1 <SEP> 10.0
<tb> 107 <SEP> 23 <SEP> 6.2 <SEP> 0.030 <SEP> 6.0 <SEP> 8.1 <SEP> 12.0
<tb> 108 <SEP> 24 <SEP> 8.3 <SEP> 0.040 <SEP> 8.6 <SEP> 10.0 <SEP> 16.0
<tb> 109 <SEP> 25 <SEP> 10.2 <SEP> 0.050 <SEP> 10.0 <SEP> 12.1 <SEP> 20.0
<tb> 110 <SEP> 26 <SEP> 11.3 <SEP> 0.060 <SEP> 11.1 <SEP> 14.0 <SEP> 22.0
<tb> 111 <SEP> 27 <SEP> 13.3 <SEP> 0.070 <SEP> 13.0 <SEP> 17.1 <SEP> 26.0
<tb> 112 <SEP> 28 <SEP> 16.3 <SEP> 0.080 <SEP> 16.2 <SEP> 20.1 <SEP> 32.0
<tb> 113 <SEP> 29 <SEP> 20.1 <SEP> 0.090 <SEP> 19.0 <SEP> 26.1 <SEP> 38.0
<tb> 114 <SEP> 30 <SEP> 22.4 <SEP> 0.100 <SEP> 22.0 <SEP> 30.1 <SEP> 40.0
<Tb>
The difference between the dimensions obtained and those that were planned was within the limits of the allowed difference. No protrusions or burrs were reported on the surface of the samples between the recesses.

Examples 115-124
Samples of types 31-40 were machined by grinding wheels similar to those of Examples 35-44, as described in Examples 85-94. Microreliefs were obtained whose dimensions for each of the samples are shown in Table 12.

Table 12

<tb><SEP><SEP> dimensions obtained <SEP> of <SEP> microrelief,
<tb><SEP> Type <SEP> n <SEP>
<tb><SEP> of <SEP> of exchange <SEP> Evidement <SEP> Pas <SEP> Not
<tb><SEP> exem- <SEP> tillon <SEP> @@@@@@@ SEP> @@@
<tb> ple <SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP> dinal <SEP> trans- <SEP>
<tb><SEP> for <SEP> for <SEP> for <SEP> dine <SEP> for
<tb> h <SEP> h <SEP> b <SEP> S
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb> 115 <SEP> 31 <SEP> 4.1 <SEP> 0.020 <SEP> 4.1 <SEP> 6.1 <SEP> 8.0
<tb> 116 <SEP> 32 <SEP> 5.1 <SEP> 0.025 <SEP> 5.0 <SEP> 7s0 <SEP> 10.0
<tb> 117 <SEP> 33 <SEP> 6.1 <SEP> 0.030 <SEP> 6.0 <SEP> 8.0 <SEP> 12.0
<tb> 118 <SEP> 34 <SEP> 8.1 <SEP> 0.040 <SEP> 8.0 <SEP> 10.1 <SEP> 16.0
<tb> 119 <SEP> 35 <SEP> 10.0 <SEP> 0.050 <SEP> 10.0 <SEP> 12.0 <SEP> 20.0
<tb> 120 <SEP> 36 <SEP> 11.1 <SEP> 0.060 <SEP> 10.9 <SEP> 14.0 <SEP> 22.0
<tb> 121 <SEP> 37 <SEP> 13.3 <SEP> 0.070 <SEP> 13.0 <SEP> 17.1 <SEP> 26.0
<tb> 122 <SEP> 38 <SEP> 16.4 <SEP> 0.080 <SEP> 16.0 <SEP> 20.0 <SEP> 32.0
<tb> 123 <SEP> 39 <SEP> 20.1 <SEP> 0.090 <SEP> 19.0 <SEP> 26.0 <SEP> 38.0
<tb> 124 <SEP> 40 <SEP> 22.2 <SEP> 0.100 <SEP> 22.0 <SEP> 30.0 <SEP> 40.1
<Tb>
The difference between the dimensions obtained and those predicted was within the limits of the allowed deviation. No outgrowth or burr was reported on the surface of the samples.

Examples 125-134
Specimens 41-50 described in Examples 45-54, which were attached between the tips of a device with a continuous rotation mechanism, were machined. The aforementioned device was installed on the table of a plane grinding machine so that the sample is disposed at a predetermined angle &alpha; relative to the plane of rotation of a tool head 10 (see Figs. 17 and 18) fixed in the spindle of the mentioned grinding machine. Before machining, the tool head 10 has been adjusted to a depth of cut equal to the depth h of the microrelief to obtain.

 The tool head 10 was rotated about the axis M while the sample was driven intermittently with a continuous rotational movement around its own axis at a speed n3 and in opposition to the rotation of the axis. the tool head. After choosing the speed n3 of continuous rotation of the sample, the speed n0 of rotation of the plate and the rotation speed n of the grinding wheel, as shown in Table 5, the values of the elements of the microrelief were determined. , which are function of it, using formulas (16) and (17). The other elements of the microrelief and test parameters were similar to those shown in Table 5. The results of the calculations and tests are shown in Table 13 (the verticals in Table 13 are numbered in accordance with the numbering adopted in the table. 5).

Table 13

<tb><SEP> N <SEP> Type <SEP> Predicted <SEP> Dimensions <SEP> Dimensions <SEP> calcu
<SEP> of <SEP> of <SEP> microrelief <SEP><SEP> of <SEP> microrelief
<tb> exem- <SEP> chan- <SEP> Profon- <SEP> Lar- <SEP> Angle <SEP> of <SEP> Lon- <SEP> No <SEP> cir
<tb> ple <SEP> tillon <SEP>, <SEP> geur <SEP> vation <SEP> of <SEP> the <SEP>, <SEP>,
<tb><SEP> mm <SEP> mm <SEP> line <SEP> helical <SEP> mm <SEP> mm
<tb><SEP> h <SEP> b <SEP> dale, <SEP>&alpha;<SEP><SEP><SEP> S1 <SEP> S
<tb><SEP> 1 <SEP> 2 <SEP> 6 <SEP> 7 <SEP> 8 <SEP>5;<SEP> 9 <SEP>
<tb><SEP> 1 <SEP> 2 <SEP> 3 <SEP> 4 <SEP> 5 <SEP> 6 <SEP> 7
<tb> 125 <SEP> 41 <SEP> 0.02 <SEP> 2 <SEP> 1.00 '<SEP> 2.08 <SEP> 4.00
<tb> 126 <SEP> 42 <SEP> 0.03 <SEP> 3 <SEP> 1.10 '<SEP> 3.06 <SEP> 5.00
<tb> 127 <SEP> 43 <SEP> 0.04 <SEP> 4 <SEP> 10101 <SEP> 4.08 <SEP> 6.25 <SEP>
<tb> 128 <SEP> 44 <SEP> 0.05 <SEP> 5 <SEP> 1 10 '<SEP> 5.13 <SEP><SEP> 8.36
<tb> 129 <SEP> 45 <SEP> 0.06 <SEP> 6 <SEP> 1 10 '<SEP> 6.13 <SEP> 10.43
<tb> 130 <SEP> 46 <SEP> 0.07 <SEP> 7 <SEP> 1 10 '<SEP> 7.16 <SEP> 11.9
<tb> 131 <SEP> 47 <SEP> 0.08 <SEP> 8 <SEP> 1 10 '<SEP> 8.17 <SEP> 13.88
<tb> 132 <SEP> 48 <SEP> 0.09 <SEP> 9 <SEP> 1 10 '<SEP> 9.20 <SEW> 15.58 <SEP>
<tb> 133 <SEP> 49 <SEP> 0.10 <SEP> 10 <SEP> 1 10 '<SEP> 10.13 <SEP> 17.13 <SEP>
<tb> 134 <SEP> 50 <SEP> 0.10 <SEP> 11 <SEP> 100 <SEP> 11.24 <SEP> 20.93
<Tb>
Table 13 (continued)

<tb><SEP> N <SEP> SEP <SEP> dimensions obtained from
<tb><SEP> of <SEP> microrelief
<tb><SEP> exem
<tb><SEP> magpie
<tb> h <SEP> b <SEP>&alpha;<SEP><SEP><SEP> s
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23 <SEP>
<tb><SEP> 8 <SEP> 9 <SEP> 10 <SEP> It <SEP><SEP> 12 <SEP> 13 <SEP><SEP> 14
<tb><SEP> 125 <SEP> 41 <SEP> 2.1 <SEP> 0.02 <SEP> 2.0 <SEP> 1.00 <SEP> 4.0
<tb><SEP> 126 <SEP> 42 <SEP> 3.1 <SEP> 0.03 <SEP> 3.0 <SEP> 1101 <SEP> 5.0
<tb><SEP> 127 <SEP> 43 <SEP> 4.1 <SEP> 0.04 <SEP> 4.0 <SEP> 1.10 '<SEP> 6.3
<tb><SEP> 128 <SEP> 44 <SEP> 5.2 <SEP> 0.05 <SEP> 5.0 <SEP> 1.10 '<SEP> 8.4
<tb><SEP> 129 <SEP> 45 <SEP> 6.2 <SEP> 0.06 <SEP> 6.0 <SEP> 1 10 <SEP> 10.5
<tb><SEP> 130 <SEP> 46 <SEP> 7.2 <SEP> 0.07 <SEP> 7.0 <SEP> 1.10 '<SEP> 12.0
<tb><SEP> 131 <SEP> 47 <SEP> 8.2 <SEP> 0.08 <SEP> 8.0 <SEP> 1-10 '<SEP> 13.9
<tb><SEP> 132 <SEP> 48 <SEP><SEP> 9.2 <SEP> 0.09 <SEP> 9.0 <SEP> 1.10 '<SEW> 15.6
<tb><SEP> 133 <SEP> 49 <SEP> 10.2 <SEP> 0.10 <SEP> 10.0 <SEP> 1.10 '<SEP> 17.2
<tb><SEP> 134 <SEP> 50 <SEP> 11.3 <SEP> 0.10 <SEP> 11.0 <SEP> 1X00 '<SEP> 20.9
<Tb>
The difference between the dimensions obtained and those that had been predicted or calculated was within the allowed range. No growth or burr was reported on the surface of the samples between the recesses.

Examples 135-144
Samples of types 51-60 were machined by grinding wheels similar to those of Examples 55-64 and as described in Examples 125-134.

Microreliefs were obtained whose dimensions for each of the samples are shown in Table 14.

Table 14

N <SEP> Type <SEP> Dimensions <SEP> Obtained <SEP> from <SEP> microrelief
<tb><SEP> of <SEP> of exchange <SEP> Evidence <SEP> Angle <SEP> No
<tb><SEP> exem- <SEP> tillon <SEP> of elevation <SEP> circu
<SEP> ple <SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP><SEP> of <SEP>,
<tb><SEP>,<SEP> line, <SEP> geur, <SEP> the <SEP> line
<tb><SEP> mm <SEP> mm <SEP> mm <SEP> helical <SEP>
<tb><SEP> dale
<tb><SEP> S1 <SEP> h <SEP> b <SEP>&alpha;<SEP><SEP> S
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 135 <SEP> 51 <SEP> 2.0 <SEP> 0.02 <SEP> 2.0 <SEP> 100 <SEP> 4.0
<tb><SEP> 136 <SEP> 52 <SEP> 3.1 <SEP> 0.03 <SEP> 3.0 <SEP> 1 10 '<SEP> 5.1
<tb><SEP> 137 <SEP> 53 <SEP> 4.2 <SEP> 0.04 <SEP> 4.0 <SEP> 1 10 '<SEP> 6.2
<tb><SEP> 138 <SEP> 54 <SEP> 5.1 <SEP> 0.05 <SEP> 5.0 <SEP> 1 10 '<SEP> 8.5
<tb><SEP> 139 <SEP> 55 <SEP> 6.2 <SEP> 0.06 <SEP> 6.0 <SEP> 1 10 <SEP> 10.4
<tb><SEP> 140 <SEP> 56 <SEP> 7.2 <SEP> 0.07 <SEP> 7.0 <SEP> 1 10 '<SEP> 12.1
<tb><SEP> 141 <SEP> 57 <SEP> 8.2 <SEP> 0.08 <SEP> 8.0 <SEP> 1 10 <SEP> 13.9
<tb><SEP> 142 <SEP> 58 <SEP> 9.2 <SEP> 0.09 <SEP> 9.0 <SEP> 1 10 '<SEW> 15.7
<tb> 143 <SEP> 59 <SEP> 10.2 <SEP> 0.10 <SEP> 10.0 <SEP> 1 10 '<SEP> 17.5
<tb><SEP> 144 <SEP> 60 <SEP> 11.4 <SEP> 0.10 <SEP> 11.1 <SEP> 100 <SEP> 21.0
<Tb>
The difference between the dimensions obtained and those which had been planned or calculated was within the limits of the allowed difference. The surface between the recesses showed no protuberance or burr.

Examples 145-154
Samples of types 61-70 were machined by grinding wheels similar to those of Examples 65-74 and as described in Examples 125-134.

Microreliefs were obtained whose dimensions for each of the samples are shown in Table 15.

Table 15

<tb><SEP> dimensions obtained <SEP> of <SEP> microrelief
<tb><SEP> N <SEP> Type
<tb><SEP> of exchange <SEP> Evidence <SEP> Angle <SEP> No
<tb> example <SEP> of <SEP> up <SEP><SEP> Lon- <SEP><SEP> Lar- <SEP><SEP> of <SEP>,
<tb><SEP>,<SEP> line, <SEP> geur, <SEP> the <SEP> line
<tb><SEP> mm <SEP> mm <SEP> mm <SEP> helical <SEP>
<tb><SEP> dale
<tb><SEP> h <SEP> b <SEP>&alpha;<SEP><SEP><SEP> S
<tb><SEP> 1 <SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 145 <SEP> 61 <SEP> 2.2 <SEP> 0.02 <SEP> 2.0 <SEP> 1.00 <SEP> 4.1
<tb><SEP> 146 <SEP> 62 <SEP> 3.2 <SEP> 0.03 <SEP> 3.0 <SEP> 1 10 '<SEP> 5.1
<tb><SEP> 147 <SEP> 63 <SEP> 4.2 <SEP> 0.04 <SEP> 4.1 <SEP> 1X10 '<SEP> 6.2
<tb><SEP> 148 <SEP> 64 <SEP><SEP> 5.2 <SEP> 0.05 <SEP> 5.0 <SEP> 1.10 '<SEP> 8.3
<tb><SEP> 149 <SEP> 65 <SEP> 6.2 <SEP> 0.06 <SEP> 6.0 <SEP> 1 10 <SEP> 10.3
<tb> 150 <SEP> 66 <SEP> 7.2 <SEP> 0.07 <SEP> 7.0 <SEP> 1 10 '<SEP> 12.1
<tb><SEP> 151 <SEP> 67 <SEP> 8.3 <SEP> 0.08 <SEP> 8.0 <SEP> 1.10 '<SEP> 13.9
<tb> 152 <SEP> 68 <SEP> 9.2 <SEP> 0.09 <SEP> 9.1 <SEP> 1 10 '<SEP> 15.7
<tb> 153 <SEP> 69 <SEP> 10.2 <SEP> 0.10 <SEP> 10.0 <SEP> 1 10 '<SEP> 17.2
<tb><SEP> 154 <SEP> 70 <SEP> 11.4 <SEP> 0.10 <SEP> 11.1 <SEP> 100 <SEP> 21.0
<Tb>
The difference between the dimensions obtained and those that were planned or calculated was within the range of the allowed deviation. no growth or burr was reported on the surface of the samples.

Examples 155-164
Samples of types 71-80 were machined with wheels analogous to those of Examples 75-84 and as described in Examples 125-134.

This resulted in microreliefs whose dimensions for each of the samples are shown in Table 16 below.
Table 16

<tb><SEP> N <SEP><SEP> Sizes <SEP> obtained from <SEP> microrelief
<tb><SEP> of <SEP> Type
<tb><SEP> exem- <SEP> of exchange <SEP> Evidence <SEP> Angle <SEP> No
<tb><SEP> ple <SEP> tillon <SEP> of elevation <SEP> circu
<tb><SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP><SEP> of <SEP>,
<tb><SEP>,<SEP> line, <SEP> geur, <SEP> the <SEP> line
<tb><SEP> mm <SEP> mm <SEP> mm <SEP> helical <SEP>
<tb><SEP> dale
<tb> h <SEP> b <SEP>&alpha;<SEP><SEP><SEP> S
<tb><SEP> 2 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23
<tb><SEP> 155 <SEP> 71 <SEP> 2.1 <SEP> 0.02 <SEP> 2.0 <SEP> 100 <SEP> 4.1
<tb><SEP> 156 <SEP> 72 <SEP> 3.0 <SEP> 0.03 <SEP> 3.0 <SEP> 1.10 '<SEP> 5.1
<tb><SEP> 157 <SEP> 73 <SEP> 4.2 <SEP> 0.04 <SEP> 4.0 <SEP> 1 10 '<SEP> 6.3
<tb><SEP> 158 <SEP> 74 <SEP> 5.3 <SEP> 0.05 <SEP> 5.0 <SEP> 1.10 '<SEP> 8.5
<tb><SEP> 159 <SEP> 75 <SEP> 6.2 <SEP> 0.06 <SEP> 6.0 <SEP> 1.10 '<SEP> 10.6
<tb><SEP> 160 <SEP> 76 <SEP> 7.3 <SEP> 0.07 <SEP> 7.0 <SEP> 1 10 '<SEP> 12.1
<tb><SEP> 161 <SEP> 77 <SEP> 8.1 <SEP> 0.08 <SEP> 8.0 <SEP> 1.10 '<SEW> 14.0
<tb><SEP> 162 <SEP> 78 <SEP> 9.2 <SEP> 0.09 <SEP> 9.0 <SEP> 1.10 '<SEW> 15.6
<tb><SEP> 163 <SEP> 79 <SEP> 10.3 <SEP> 0.10 <SEP> 10.0 <SEP> 1.10 '<SEP> 17.2
<tb><SEP> 164 <SEP> 80 <SEP> 11.4 <SEP> 0.10 <SEP> 11.0 <SEP> 1.00 <SEP> 21.0
<Tb>
The difference between the dimensions obtained and those which had been planned or calculated was within the limits of the allowed difference. No outgrowth or burr was reported on the surface of the samples.

 Another embodiment of the method according to the invention consists in that the periodic action on the surface to be machined of the part 3 is operated, the axis F of rotation of the grinding wheel 1 being mobile, by the cutting surface. 24 of said grinding wheel, which surface is constituted by separate portions 25 arranged at a determined pitch along the periphery of the wheel 1 mentioned.

 Before machining, the grinding wheel 1 is adjusted for a predetermined depth of cut equal to the depth of the microrelief to be obtained. The relative movement along the arrow A is then communicated to the piece 3, parallel to the surface 2 to be machined. In this embodiment, the advancement of the part 3 in the direction indicated by the arrow A has a continuous character.

In the case of a part 3 in the form of a body of revolution (FIG. 22), the continuous movement of the part operates in two directions and is then due to the rotation of the part 3 around its own axis and to its axial displacement obtained with the help of the table of the grinding machine.

The axis F of the grinding wheel 1 is, in this case, parallel to the axis of rotation of the workpiece 3, or is arranged at a small angle with respect to the latter, from which a microrelief resulting from a helicoidal line with an inclination angle o (see Figure 10).

 When operating with a grinding wheel 1 whose cutting surface 24 is constituted by portions 25 arranged at a determined pitch, the recess 5 of the microrelief (FIGS. 21 and 22) has a slightly different shape from that of a segment and consists of three portions: two extreme portions of length k and kt figures 21 and 22, respectively), whose form is close to that of a half-segment, and a median portion of length g ( Figures 21 and 22), wherein the wall of the recess has the shape of a surface equidistant from the surface 2 to be machined.

le terme

étant la longueur de la corde d'un segment obtenu dans la pièce 3 immobile lors de la rotation de la meule 1, et le terme V3tf étant l'accroissement de la longueur de cette corde dû au déplacement de la pièce à la vitesse V3
La longueur s de la portion médiane est le chemin que la pièce parcourt pendant le corps tl de rotation de la meule 1 d'un angle correspondant à la longueur l1 de ltarc embrassant la portion 25 de la surface de coupe de ladite meule
g 3 V3 . t1. (20)
Le temps t + faisant partie de l'expression (19) et celui tl apparaissant dans l'expression (20) peuvent être déterminés chacun comme le quotient du chain parcouru respectif par la vitesse de rotation de la meule 1, la longueur de l'arc correspondant à l'angle # pouveat être remplacée, sans trop l'ire à la précision des calculs, par la longueur de la corde 2#Dh . En introduisant les valeurs mentionnées dans la formule (18), on ebtient

The length of the recess 4 can thus be represented as the sum of the lengths of said portions, which, in the case of a flat surface part 2, is expressed as follows:
S1 = 2k + g (18)
The first term of the sum above is the path traveled by a point of the grinding wheel 1 in the piece 3 during the time t P of rotation of said grinding wheel of an angle

the term

being the length of the chord of a segment obtained in the immovable part 3 during the rotation of the grinding wheel 1, and the term V3tf being the increase in the length of this chord due to the displacement of the part at the speed V3
The length s of the middle portion is the path that the part travels during the body tl of rotation of the grinding wheel 1 by an angle corresponding to the length l1 of ltarc embracing the portion 25 of the cutting surface of said grinding wheel
g 3 V3. t1. (20)
The time t + forming part of the expression (19) and that tl appearing in the expression (20) can each be determined as the quotient of the respective chain traveled by the speed of rotation of the wheel 1, the length of the arc corresponding to the angle # can be replaced, without too much anger to the precision of calculations, by the length of the rope 2 # Dh. By introducing the values mentioned in formula (18), one obtains

où V3 est la vitesse du mouvement de translation de la
pièce 3 dans la direction indiquée par la flèche A;
T est le temps de rotation de la meule 1 autour de
son axe;;
Z est le nombre de portions 25 de la surface de
coupe 24, considérées dans le plan sectionnant la
meule 1 perpendiculairement à son axe de rotation;
n est la vitesse de rotation de la meule 1.It is obvious that the pitch S of the microrelief can be determined as the path traveled by the part during the time t1 of rotation of the grinding wheel 7 by an angle corresponding to the arc 1 which, in turn, corresponds to the interval between two portions 25 adjacent to the cutting surface 24

where V3 is the speed of the translational motion of the
Exhibit 3 in the direction indicated by the arrow A;
T is the rotation time of the grinding wheel 1 around
its axis;
Z is the number of portions 25 of the surface of
section 24, considered in the plan sectioning the
grinding wheel 1 perpendicular to its axis of rotation;
n is the speed of rotation of the wheel 1.

The length of the recess 4 of the microrelief obtained on a rotating surface (FIG. 22) by means of a grinding wheel 1 whose portions 25 forming the cutting surface 24 are arranged in a certain pitch can also be determined as the sum of the lengths of three portions
SQ 2k 'g (23)
As in the case of a flat part, the first of the two terms is the path traveled by a point of the grinding wheel 1 in the part 3 during the time t of rotation of said grinding wheel by a corresponding angle, and can be determined , without unduly detracting from the precision of the calculations, as the sum of the length of the cord of two circumferences, one of which is of diameter D and the other of diameter d (which corresponds to the length of the recess 4 in the case of a motionless part), and the increase in the length of this rope due to the rotation of the part at speed n3

The second term can be expressed with sufficient accuracy for practical purposes, by the length of an arc circumference diameter d, corresponding to the rotation angle of the part 3 during the rotation time of the wheel 1 to the value 11 of the portion 25 of the cutting surface 24

Thus, the length Sn of the recess, estimated according to the bend of the circumference considered in section of the part, can be determined using the expression

The angular pitch g between the recesses of the microrelief is determined by starting from the equality between the rotation time of the piece 3 at this step and the rotation time of the grinding wheel 1 about its axis of the angle corresponding to a not alone

 To obtain a microrelief composed of separate recesses, the number Z of portions 25 forming the cutting surface 24 of the grinding wheel 1 and considered in the plane sectioning said grinding wheel perpendicular to its axis of rotation, must not exceed 4 Otherwise, as shown in practice, the cutting edge of each portion 25 completely intersects the portions of the surface 2 of the workpiece, between recesses, unaffected by the previous portion.

 The length 11 of the respective portion, considered in the similar plane when Z P 1, shall not exceed 11/12 of the length of the circumference corresponding to the greatest radius of the cutting surface 24.

The above-mentioned limit corresponds to the minimum value (FIG. 21) of the interval separating the terminal and initial edges of the portion 25 (which interval is normally in the form of a cavity), when it is still possible to obtain a step S of the recesses greater than the length S1 of each of said recesses.

The length 12 of said cavity being smaller, it is not possible to obtain separate recesses 4 which, because they are too long, then form a continuous groove whose width corresponds to the width of the grinding wheel 1.

 It should be noted here that the limit length 11 of the portion 25 that is chosen in each particular case, starting from the depth h of the microrelief to be obtained and the diameter of the grinding wheel, can in principle be of different values determined by the expectation or calculations. The value 11/12 s D is the limit value 11 above which it is not possible to obtain separate recesses, whatever the machining conditions.

 The minimum length 11 of each portion 25 is determined by the desired holding of the grinding wheel, on which this length influences. The strength mentioned also depends on the speed V 3 of displacement of the part and the speed n of rotation of the grinding wheel 1. It has been determined always by experimentation that the length i 1 of the circumference arc corresponding to the largest radius of the cutting surface of a grinding wheel 1, 50 mm in diameter should not be less than 13 pila, Only then can it be obtained, the depth of the recesses to obtain being 0.004-0.005 na, a holding of the wheel 1 equal to 5 minutes.

In the case of flat surfaces 2, the length 11 of the portion 25 of the cutting surface of the grinding wheel 1 can be easily determined by solving the system of equations (21) and (22) and starting from values S and S predetermined

An operation is analogous in the case of the surfaces 2 of the body of revolution. Then the length 11 of the portion 25 is determined starting from the values
S1 and d according to equations (26) and (27)

The interval 1 of the portions 25 along the circumference arc corresponding to the largest radius of the surface of the grinding wheel 1 also varies in a large glove, which, however, has limits and is generally a function of the pitch S of microrelief to obtain.Basing on the obvious equality = ## (30) and following the expression (22) one obtains, the elementary trangioruations being made

 It has been experimentally determined that the micro-relief in question can only be obtained if step 1 of the portions 25 is not less than 245 and greater than 6005. Any non-observation of this condition will require, in the first case, a decrease unacceptable speed of rotation of the wheel, which may result in poor stability of the cutting process, an increase in the load on the abrasive grains and, ultimately, destruction of the grinding wheel.In the second case, step 1 being greater than 6005, it would be an inadmissible increase in the speed of rotation of the wheel, which could lead to its bursting. The limits mentioned are valid for the machining of all kinds of surfaces provided that the pitch S of the microrelief is measured along this surface (for the surfaces of revolution, following an arc of circumference).

In the case of a grinding wheel whose portions 25 are arranged in a certain pitch, its minimum strength can be obtained if the diameter D is equal, at least, to 50 mm. When seeking a microrelief should the depth is greater than 0.005 mm, the diameter, admitted at least from the point of view of the holding of the grinding wheel, can be determined, depending on the depth h, according to the empirical formula
D = 100 [1 + (h - 0.01). 100] mm (32)
The grinding wheel 1 provided for carrying out the described embodiment of the method according to the invention comprises working elements 26 carrying the mentioned portions 25 of the cutting surface 24 and arranged at a certain pitch along the periphery of the grinding wheel. .

These work items can occur in many ways.

 For example, in the case of one-piece wheels, they are alternating radial projections with cavities and forming an intermittent cutting surface (see FIG. 21). In composite wheels, the elements 26 are abrasive insertion pieces in the form of annular sectors or segments mounted on a plate.

Then the insertion parts can be arranged on the periphery of the plate, in several rows (a row comprises the insertion parts seen in the same plane perpendicular to the axis of rotation of the wheel). In order to obtain dynamic conditions favorable to the operation of a grinding wheel whose insertion pieces form several rows, it is rational to move the insertion pieces forming a row with respect to those forming the neighboring row, as for grinding wheels 1 of the tool head 10 (FIGS. 19 and 20).

The optimal version consists of arranging them in chessboard.

 When viewed in cross-section, each of the working elements of the cutting surface has lateral roundings of radius r8 equal to 1-3 n, for the same reasons as those for which the edges of the cutting surface are rounded. grinding wheels forming part of the tool head 10.

 One of the embodiments of the grinding wheel 1 provided with an intermittent cutting surface provides the possibility of adjusting the arrangement of the work elements 26 radially (see FIGS. 23, 24 and 25).

 A grinding wheel 1 of this type comprises a composite plate 27 (FIGS. 24 and 25) in the annular notch 28 of which, provided with lateral walls parallel to the faces of said plate, are housed slides 29 arranged for sliding and supporting elements of 26 which are in the form of annular sectors cut laterally and made of abrasive material. Each of the slides 29 is provided with a clamping member 30 having movable and fixed jaws, and a shank 31 installed in the notch 28 of the plate 27 and immobilized in said notch by means of screws 32 passing through parallel housings 33 formed in the tail and oriented along the shelf radius 27.

 Mounted on the hub 34 of the plate 27, between the walls of its notch 28, is a ring 35, rotatable and provided with a blade 36 (Figure 25). The ring 35 is connected to each of the sliders 29 (FIG. 23) via a hinge element 37.

When it is necessary to move the work elements 26 to compensate for their wear, the screws 32 are loosened and the ring 35 is turned by hand until the division of the blade 36 which corresponds to "zero" coincides with "zero". to the value of wear. During this operation, the hinge elements 37 rotate relative to the joints by which they are connected to the tails 31 of the sliders 29, and thus push said sliders 2
These move radially along the screws 32. The ring 35 is rotated by the desired angle, the sliders 29 are again fixed in the notches 28 with the screws 32. The radial adjustment of the arrangement of the Work elements 26 allows, during a long period of operation of the grinding wheel, to maintain with a perfect precision the desired dimensions of the microrelief.

As the operations of replacing grinding wheels become less frequent, time is obtained to increase the efficiency of machining. Such a wheel also makes it possible to save the abrasive material which, in the non-settable tools of the work elements, is only partially used. The advantages which have just been mentioned make this embodiment of the grinding wheel preferable to the tools. with intermittent cutting surface
In another embodiment, advantageous from the point of view of the dynamic operating conditions of the tool, the working elements 26 (see FIGS. 26 to 30), which in this case are abrasive inserts in the form of sectors. annular, are fixed in the plate 27 in a fixed manner, the plate itself being, in contrast, made of an elastic abrasive material whose particle size is smaller than that of the insertion parts. The plate 27 has radial housings 38 adapted, from the torso and depth point of view, for receiving the working elements 26. In the variant shown in FIGS. 26 and 27, the grinding wheel is provided with housings 38 in the form of notches made throughout, and in the variant shown in Figures 28, 29 and 30, these dwellings are limited to four quarters.

The working elements 26 are fixed in the housings 38 with the aid of an agglomerate which is melted by heat treatment and which is similar to that which is part of the material of the tray, or else with the aid of tacky materials. .

The peripheral surface of the plate 27 and the portions 25 of the outer surface of the working elements 26 form a continuous cutting surface 24 of the grinding wheel 1, the properties of which alternate discretely.

 The properties of the abrasive insertion pieces which, as in a grinding wheel with an intermittent cutting surface, are arranged at a certain pitch along the periphery of the grinding wheel in question, make it possible to obtain microreliefs of predetermined profile and dimensions.

 The elastic properties of the tray substantially improve the operating conditions of the abrasive inserts by softening dynamic shocks which occur during the penetration of the cutting edges into the material to be machined and thereby reduce the wear of said parts, prevent overheating, etc. Because the material of the plate itself has abrasive properties, it is also possible to carry out two different operations in one pass of the grinding wheel, in particular that of formation of the microrelief and that of grinding of the surface between the recesses.

 The rigidity of the plate 27 is chosen so that, the iron plug being set in accordance with the depth of the microrelief to obtain equal to 0.004-0.1 n, the cutting surface is subjected to a pressure of 9.80 to 784. , 80 kPa.

 The particle size of the tray material is similar to that of the abrasive materials that Sploto not for grinding, but always smaller than the particle size of the abrasive insert material. The optimum ratio between the particle size of the tray and the material of the parts mentioned is 1/2.

 As the agglomerant, in the material of the plate 27, volcanic material is used or other similar materials such as: rubber, polynethanes, fluorinated plastics and the like.

 From a design point of view, the resilient tray wheels may be in different shapes.

 Represented in Figures 26 and 27, the grinding wheel comprises a disk-shaped plate whose width is equal to that of the working elements 26 engaged in its radial housing 38. The grinding wheel being designed described story, it can not rectify that the portions of the surface which separate the recesses in the longitudinal direction (in the machining direction).

 As shown in FIG. 28, the grinding wheel comprises a plate 27 of composite type which comprises, in addition to a disc 39 similar to that of FIGS. 26 and 27, discs 40 with a continuous peripheral surface whose width corresponds to the distance provided between the rows of recesses of the microrelief. This grinding wheel allows the grinding of the portions of the surface to be machined separating the recesses in the longitudinal direction as well as in the transverse direction.

 Figures 29 and 30 show a grinding wheel 1 whose work elements 26 are several rows.

As in the intermittent cutting surface grinding wheel, which grinding wheel has been described above, the working elements 26 forming a row are moved relative to the working elements 26 of the adjacent row. This grinding wheel allows the machining of the entire surface or a considerable portion of it in a single pass.

 During the machining of the surface 2 of the part 3 in order to obtain a regular microrelief (see FIG. 28), the working elements 26 cut the metal of the surface layer by forming recesses, as in the case a grinding wheel whose portions of the cutting surface are arranged at a certain pitch, while the portions of the peripheral surface of the plate 27, deforming on the surface during machining, remove only the vertices of the microsaillings appeared on the portions of the surface to be machined separating the recesses 4 (for more details, see Figure 31 which gives the microprofil of the surface 2 before it is subjected to machining, and Figure 32 representing the surface 2 after machining).

Each working element 26 supported elastically by the plate 27 penetrates gently, without impact, into the material being machined. The favorable dynamic conditions under which a wheel of this type operates contribute to raising its service strength.

 Removing the tops of the microsailiies which are on the friction surfaces makes it possible to completely avoid the running-in process of the parts forming part of the support assemblies or to reduce them to a minimum and, consequently, to to raise the precision and the service life of the machine tools of which said support assemblies form an integral part.

 Below are described concrete but non-limiting embodiments of the method according to the invention using grinding wheels whose portions of the cutting surface are arranged in a certain pitch.

Exeffples 165-176
200 x 90 x 20 mm plate-shaped samples made of unhardened carbon steel with a carbon content of 0.3-0.4% were rolled. To obtain a uniform microreliof on the surface of said samples, flat grinding wheels were used whose work elements were arranged in a single row and were in the form of white artificial corundum inserts (96-99s; Au203), having a particle size of 160-200Fm, dispersed in a ceramic binder. In the tests shown in Examples 172-175, grinding wheels 1 with working elements 26 of the adjustable radial type were used (see FIGS. 23-25). .

qui découle de la condition d'usinage caractérisée par le caractère continu du déplacement de la pièce, suivant la fonction empirique (32) et tout en prenant en considdratron que le diamètre D ne devait pas être inférieur à 50 n.Starting from predetermined values of the depth h and the length S1 of the recess of the microrelief, the diameter D of the grinding wheel was chosen according to the obvious inequality

which results from the machining condition characterized by the continuous character of the displacement of the workpiece, according to the empirical function (32) and taking into account that the diameter D should not be less than 50 n.

 Starting from the number Z of insertion pieces, the length 11 thereof was determined (Fig. 21) according to formula (28).

 The V3 moving speed of the table of the flat rectiiieuse has been established in accordance with the desired machining efficiency and technological capabilities of the grinding machine itself. The speed n of rotation of the only one was determined according to formula (22).

 Before machining, the grinding wheel was adjusted to a depth of cut equal to the depth h of the microrelief to be obtained.

 Each time, after obtaining a row of microrelief along the entire length of the sample plate, it was moved transversely by a step S0 and the operation was repeated.

 The results of the tests are shown in Table 17.

 As can be seen from Table 17, the microrelief obtained was as expected, with sufficient accuracy for practical purposes. no growth on the surface of the samples between the recesses has been reported.

Table 17

<SEP><SEP> Predicted <SEP> Dimensions of <SEP> Qutil
<tb><SEP> microrelief, <SEP> mm
<tb><SEP> Of course
<tb><SEP> S1 <SEP> h <SEP> b <SEP> S <SEP> S0 <SEP> D <SEP> Z <SEP> rs <SEP> l1 <SEP> l / @ <SEP> l1 / # <SEP> D
<tb><SEP> 1 <SEP> 2 <SEP> 3 <SEP> 3 <SEP> 3 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 10 <SEP> 11 <SEP> 12
<tb><SEP> 165 <SEP> 1.6 <SEP> 0.005 <SEP> 2 <SEP> 2.2 <SEP> 4 <SEP> 50 <SEP> 3 <SEP> 1.0 <SEP> 13 <SEP> 24 <SEP> 1/12
<tb><SEP> 166 <SEP> 1.6 <SEP> 0.005 <SEP> 2 <SEP> 3.3 <SEP> 4 <SEP> 50 <SEP> 2 <SEP> 1.0 <SEP> 13 <SEP> 24 <SEP> 1/12
<tb><SEP> 167 <SEP> 1.6 <SEP> 0.005 <SEP> 2 <SEP> 6.5 <SEP> 4 <SEP> 50 <SEP> 1 <SEP> 1.0 <SEP> 13 <SEP> 24 <SEP> 1/12
<tb><SEP> 168 <SEP> 5.5 <SEP> 0.005 <SEP> 5 <SEP> 6.5 <SEP> 10 <SEP> 1200 <SEP> 1 <SEP> 2.0 <SEP> 314 <SEP> 600 <SEP> 1/12
<tb><SEP> 169 <SEP> 8.0 <SEP> 0.010 <SEP> 8 <SEP> 9.5 <SEP> 16 <SEP> 600 <SEP> 2 <SEP> 2.0 <SEP> 314 <SEP> 101 <SEP> 1/6
<tb><SEP> 170 <SEP> 14.5 <SEP> 0.025 <SEP> 15 <SEP> 19.5 <SEP> 30 <SEP> 600 <SEP> 4 <SEP> 2.0 <SEP> 157 <SEP> 24 <SEP> 1/12
<tb><SEP> 171 <SEP> 7.0 <SEP> 0.030 <SEP> 7 <SEP> 11.5 <SEP> 14 <SEP> 300 <SEP> 1 <SEP> 1.5 <SE> 78, 3 <SEP> 83 <SEP> 1/12
<tb><SEP> 172 <SEP> 10.0 <SEP> 0.040 <SEP> 10 <SEP> 12.0 <SEP> 20 <SEP> 400 <SEP> 2 <SEP> 2.0 <SEP> 105 <SEP> 52.3 <SEP> 1/12
<tb><SEP> 173 <SEP> 12.5 <SEP> 0.040 <SEP> 12 <SEP> 17.0 <SEP> 24 <SEP> 400 <SEP> 3 <SEP> 2.0 <SEP> 105 <SEP> 24 <SEP> 1/12
<tb><SEP> 174 <SEP> 13.0 <SEP> 0.050 <SEP> 13 <SEP> 16.5 <SEP> 26 <SEP> 600 <SEP> 3 <SEP> 2.0 <SEP> 157 <SEP> 38.5 <SEP> 1/12
<tb><SEP> 175 <SEP> 18.5 <SEP> 0.060 <SEP> 20 <SEP> 24.5 <SEP> 40 <SEP> 600 <SEP> 1 <SEP> 2.0 <SEP> 471 <SEP> 75.5 <SEP> 1/4
<tb><SEP> 176 <SEP> 36.0 <SEP> 0.004 <SEP> 4 <SEP> 37.0 <SEP> 8 <SEP> 800 <SEP> 1 <SEP> 1.0 <SEP> 1115 <SEP> 34 <SEP> 11/12
<tb> Table 17 (continued)

<SEP> Dimensions <SEP> obtained <SEP> from
<tb><SEP> microrelief, <SEP> mm
<tb><SEP> n <SEP> V3 <SEP> 2k <SEP> S1 <SEP> h <SEP> b <SEP> S <SEP> S0
<tb><SEP> 1 <SEP> 13 <SEP> 14 <SEP> 15 <SEP> 16 <SEP> 17 <SEP> 18 <SEP> 19 <SEP> 20 <SEP> 21
<tb><SEP> 165 <SEP> 7743 <SEP> 50 <SEP> 1 <SEP> 25 <SEP> 1.7 <SEP> 0.005 <SEP> 2.0 <SEP> 2.2 <SEP> 4, 0
<tb><SEP> 166 <SEP> 7743 <SEP> 50 <SEP> 1 <SEP> 25 <SEP> 1.7 <SEP> 0.005 <SEP> 2.0 <SEP> 3.3 <SEP> 4, 0
<tb><SEP> 167 <SEP> 7743 <SEP> 50 <SEP> 1 <SEP> 25 <SEP> 1.6 <SEP> 0.005 <SEP> 2.0 <SEP> 6.6 <SEP> 4, 0
<tb><SEP> 168 <SEP> 796 <SEP> 5 <SEP> 4.89 <SEP> 21 <SEP> 5.4 <SEP> 0.005 <SEP> 5.0 <SEP> 6.2 <SEP> 10.0
<tb><SEP> 169 <SEP> 1115 <SEP> 21 <SEP> 4.9 <SEP> 9 <SEP> 8.0 <SEP> 0.010 <SEP> 8.0 <SEP> 9.3 <SEP> 16.0
<tb><SEP> 170 <SEP> 637 <SEP> 50 <SEP> 7.7 <SEP> 7 <SEP> 14.3 <SEP> 0.025 <SEP> 15.0 <SE> 19.6 <SEP> 30.0
<tb><SEP> 171 <SEP> 2230 <SEP> 25.2 <SEP> 6.0 <SEP> 9 <SEP> 7.0 <SEP> 0.030 <SEP> 7.0 <SEQ> 11.3 <SEP> 14.0
<tb><SEP> 172 <SEQ> 1671 <SEP> 40 <SEP> 8.0 <SEP> 10 <SEP> 10.1 <SEP> 0.040 <SEW> 10.0 <SEP> 12.1 <SEP> 20.0
<tb><SEP> 173 <SEP> 955 <SEP> 50 <SEP> 8.0 <SEP> 13 <SEP> 12.7 <SEP> 0.040 <SEP> 12.0 <SEP> 17.1 <SEP> 24.0
<tb><SEP> 174 <SEP> 796 <SEP> 45 <SEP> 11.0 <SEP> 7 <SEP> 13.1 <SEP> 0.050 <SE> 13.0 <SE> 16.5 <SEP> 26.0
<tb><SEP> 175 <SEP> 1115 <SEP> 27.5 <SEP> 12.0 <SEP> 4 <SEP> 18.3 <SEP> 0.060 <SEP> 20.0 <SE> 24.4 <SEP> 40.0
<tb><SEP> 176 <SEP> 1350 <SEP> 50 <SEP> 2.52 <SEP> 15 <SEP> 36.1 <SEP> 0.004 <SEP> 4.0 <SEP> 36.8 <SEP> 8.0
<Tb>
Exenyles 177-188
Tests were made of 0.12% carbon chromium steel samples with a surface hardness of 60 HRC, which samples were similar in shape and size to those of Examples 165-176. Machining was performed as described in the same examples and with similar equipment and tooling.

 The desired dimensions of the microrelief, the dimensions of the tools and the machining rates were similar to those of Examples 165-176.

 Microreliefs were obtained, the dimensions of which, for each of the samples, are shown in Table 18 and appear in the same order of succession as in Table 17.

Table 18

<tb><SEP><SEP><SEP><SEP> Dimensions obtained from <SEP> microrelief, <SEP> n <SEP>
<tb><SEP> N
<tb><SEP> of exem- <SEP> Evidement <SEP> Not <SEP> Not
<tb><SEP> ple <SEP> long- <SEP> trans
<tb><SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP> tudi- <SEP> versal
<tb><SEP><SEP><SEP><SEP>
<tb> S1 <SEP> h <SEP> h <SEP><SEP> b <SEP> S
<tb><SEP> 1 <SEP> 17 <SEP> 18 <SEP> 19 <SEP> 20 <SEP> 21
<tb><SEP> 177 <SEP> 1.7 <SEP> 0.005 <SEP> 2.0 <SEP> 2.3 <SEP> 4.0
<tb><SEP> 178 <SEP> 1.8 <SEP> 0.005 <SEP> 2.0 <SEP> 3.4 <SEP> 4.0
<tb><SEP> 179 <SEP> 1.7 <SEP> 0.005 <SEP> 2.0 <SEP> 6.6 <SEP> 4.0
<tb><SEP> 180 <SEP> 5.4 <SEP> 0.005 <SEP> 5.0 <SEP> 6.3 <SEP> 10.0
<tb><SEP> 181 <SEP> 8.1 <SEP> 0.010 <SEP> 8.0 <SEP> 9.3 <SEP> 16.0
<tb><SEP> 182 <SEP> 14.4 <SEP> 0.025 <SEP> 15.0 <SEP> 19.6 <SEP> 30.0
<tb><SEP> 183 <SEP> 7.1 <SEP> 0.030 <SEP> 7.0 <SEP> 11.4 <SEP> 14.0
<tb><SEP> 184 <SEP> 10.1 <SEP> 0.040 <SEP> 10.0 <SEP> 12.2 <SEP> 20.0
<tb><SEP> 185 <SEP> 12.6 <SEP> 0.040 <SEP> 12.0 <SEP> 17.2 <SEP> 24.0
<tb><SEP> 186 <SEP> 13.1 <SEP> 0.050 <SEP> 13.0 <SEP> 16.6 <SEP> 26.0
<tb><SEP> 187 <SEP> 18.4 <SEP> 0.060 <SEP> 20.0 <SEP> 24.5 <SEP> 40.0
<tb><SEP> 188 <SEP> 36.2 <SEP> 0.004 <SEP> 4.0 <SEP> 37.0 <SEP> 8.0
<Tb>
The difference between the dimensions obtained and those which had been planned was within the limits of the allowed difference. The surface of the samples showed no protuberance or burr between the recesses.

Examples 189-194
Samples analogous to those of Examples 180-185 were machined, as described in the same examples, but using elastic plateau wheels (see Figure 28). Tool dimensions and machining rates were similar to those given in Table 17 for Examples 168-173.

The abrasive insertions were made of white artificial corundum dispersed in a volcanic-based agglomerator. The material of the tray contained, as agglomerant, rubber. The granuiometry of the material of the abrasive insertions was 160-200 μm, and that of the material of the plate, 50-63 μm. The iron setting effort was 294.3 kPa. The initial roughness of all samples was 2.5 m.

 Microreliefs were obtained, the dimensions of which, within the limits of the allowed deviation, corresponded to those shown in Table 18 (Examples 180-185).

The roughness of the surface between the recesses constituted, after machining, 1-1.25m. It has been found that the resistance of the elastic-bed wheels has on average increased by 1.5 times compared with those of Examples 180-185.

Examples 195-206
The machining of tin-fluorine bronze samples was subjected whose shape and dimensions were similar to those of Examples 165-176. For this purpose we used the grinding wheels described in the same examples. The abrasive inserts were black silicon carbide (greater than 95% SiC) with a particle size of 160 to 200 μm dispersed in a ceramic binder. In Examples 202-205, grinding wheels 1 with radially adjustable working elements 26 were used (see FIGS. 23-25).

 The expected dimensions of the microrelief, the dimensions of the tools and the machining rates were as in Examples 165-176.

 Microreliefs were obtained, the dimensions of which, for each of the samples, are collated in Table 19 in the same order of succession as the similar data in Table 17.

Table 19

<tb><SEP><SEP> dimensions obtained <SEP> of <SEP> microrelief, <SEP> mm
<tb><SEP> N
<tb><SEP> d
<tb> exem- <SEP> Evidently <SEP> Not <SEP> Not
<tb> ple <SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP> longitu- <SEP> trans
<tb><SEP><SEP><SEP><SEP> final <SEP>
<tb><SEP> S1 <SEP> h <SEP> b <SEP> S <SEP> S0
<tb><SEP> 1 <SEP> 18 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22
<tb><SEP> 195 <SEP> 1.7 <SEP> 0.005 <SEP> 2.0 <SEP> 2.3 <SEP> 4.0
<tb><SEP> 196 <SEP> 1.9 <SEP> 0.005 <SEP> 2.0 <SEP> 3.4 <SEP> 4.0
<tb><SEP> 197 <SEP> 1.8 <SEP> 0.005 <SEP> 2.0 <SEP> 6.6 <SEP> 4.0
<tb><SEP> 198 <SEP> 5.5 <SEP> 0.005 <SEP> 5.0 <SEP> 6.3 <SEP> 10.0
<tb><SEP> 199 <SEP> 8.2 <SEP> 0.010 <SEP> 8.0 <SEP> 9.4 <SEP> 16.0
<tb><SEP> 200 <SEP> 14.4 <SEP> 0.025 <SEP> 15.0 <SEP> 19.6 <SEP> 30.0
<tb><SEP> 201 <SEP> 7.2 <SEP> 0.030 <SEP> 7.0 <SEP> 11.2 <SEP> 14.0
<tb><SEP> 202 <SEP> 10.2 <SEP> 0.040 <SEP> 10.0 <SEP> 12.1 <SEP> 20.0
<tb><SEP> 203 <SEP> 12.7 <SEP> 0.040 <SEP> 12.0 <SEP> 17.2 <SEP> 24.0
<tb><SEP> 204 <SEP> 13.1 <SEP> 0.050 <SEP> 13.0 <SEP> 16.4 <SEP> 26.0
<tb><SEP> 205 <SEP> 18.5 <SEP> 0.060 <SEP> 20.0 <SEP> 24.5 <SEP> 40.0
<tb><SEP> 206 <SEP> 36.3 <SEP> 0.004 <SEP> 4.0 <SEP> 37.1 <SEP> 8.0
<Tb>
The difference between the dimensions obtained and those which had been planned was within the limits of the allowed difference. no excrescence was reported on the surface of the samples between the recesses.

Exeurpies 207-218
Samples of hardened nickel-chrone cast iron with a surface hardness of 675 BB were tested. The shape and dimensions of the samples were as those of Examples 165-176, machining was carried out as described in the same examples using similar tools. The abrasive inserts were made of green silicon carbide (greater than 97% SiC) with a particle size of 160-200 μm, dispersed in a ceramic bond.

 In Examples 214-217, grinders with radially adjustable work elements were used (see Figures 23-25).

 The expected dimensions of the microrelief were as in Examples 165-176. the same was true for tool dimensions and machining rates.

 Microreliefs were obtained, the dimensions of which for each of the samples are shown in Table 20 and appear in the same order of succession as in Table 17.

Table 20

<tb> N <SEP><SEP> dimensions obtained <SEP> of <SEP> microrelief, <SEP> mm
<tb> of exem- <SEP> Evidement <SEP> Not <SEP> Not
<tb><SEP> ple <SEP> longitu- <SEP> trans
<tb><SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP> dinal <SEP> versal
<tb><SEP><SEP><SEP>
<tb><SEP> S1 <SEP> h <SEP> b <SEP> S <SEP> S0
<tb><SEP> 1 <SEP> 18 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22
<tb> 207 <SEP> 1.7 <SEP> 0.005 <SEP> 2.0 <SEP> 2.3 <SEP> 4.0
<tb> 208 <SEP> 1.7 <SEP> 0.005 <SEP> 2.0 <SEP> 3.3 <SEP> 4.0
<tb> 209 <SEP> 1.7 <SEP> 0.005 <SEP> 2.0 <SEP> 6.6 <SEP> 4.0
<tb> 210 <SEP> 5.5 <SEP> 0.005 <SEP> 5.0 <SEP> 6.2 <SEP> 10.0
<tb> 211 <SEP> 8.1 <SEP> 0.010 <SEP> 8.0 <SEP> 9.4 <SEP> 16.0
<tb> 212 <SEP> 14.3 <SEP> 0.025 <SEP> 15.0 <SEP> 19.5 <SEP> 30.0
<tb> 213 <SEP> 7.1 <SEP> 0.030 <SEP> 7.0 <SEP> 11.3 <SEP> 14.0
<tb> 214 <SEP> 10.1 <SEP> 0.040 <SEP> 10.0 <SEP> 12.1 <SEP> 20.0
<tb> 215 <SEP> 12.7 <SEP> 0.050 <SEP> 12.0 <SEP> 17.1 <SEP> 24.0
<Tb>
Table 20 (continued)

<tb><SEP> 1 <SEP> 18 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22
<tb> 216 <SEP> 13.1 <SEP> 0.050 <SEP> 13.0 <SEP> 16.4 <SEP> 26.0
<tb> 217 <SEP> 18.4 <SEP> 0.060 <SEP> 20.0 <SEP> 24.4 <SEP> 40.0
<tb> 218 <SEP> 36.2 <SEP> 0.004 <SEP> 4.0 <SEP> 36.9 <SEP> 8.0
<Tb>
The difference between the dimensions obtained and those which had been planned was within the limits of the allowed difference. no excrescence was reported on the surface of the samples between the recesses.

Exemptions 219-231
In order to obtain regular sicrorelleis on the rotating surfaces, cylindrical samples made of unhardened carbon steel with a carbon content of 0.3-0.4% were machined. For this purpose grinding wheels were used whose working elements were in the form of abrasive inserts made of artificial corundum (96-99% of Al 2 O 3) with a particle size of 160-20%, dispersed in a ceramic binder, arranged in only one row. In Examples 225-230, the grinding wheels 1 had radially adjustable working members 26 (see Figs. 23-25).

 Starting from the predetermined values of the depth h and the length S1 and on the basis of the same considerations as in Examples 165-176, the diameter D of the grinding wheels was chosen.

 For all the samples, an angular pitch 6 equal to 6 was admitted. Starting from the number Z of insertion pieces, the length of each of them was determined, according to the cutting surface of the wheel, using of the formula (29).

 The speed n3 of rotation of the sample was determined according to the formula (27) starting from the predetermined speed n of rotation of the grinding wheel.

 In calculating the machining rates and grinding wheel parameters, the chosen values were arbitrarily corrected by substituting them for the formula (26) and resulting in a methodical comparison of the respective starting values.

 The samples were installed between the tips of a cylindrical grinding machine at an angle oS predetermined with respect to the plane of rotation of the grinding wheel.

 Before machining, the grinding wheel was adjusted to the desired depth of cut, equal to the depth h of the microrelief.

 During machining, the samples were fed continuously in the axial direction by means of the grinding machine table, which table moved at a speed corresponding to the expected elevation angle of the helical disposition line. recesses (the speed in question corresponded to the axial pitch SO determined according to formula (7).

 The results of the tests are shown in Table 21.

 The difference between the dimensions obtained and those which had been planned was within the limits of the allowed difference. no growth was reported between the recesses.

Table 21

<SEP> Dimensions <SEP> SEP <SEP> Planned Dimensions <SEP> Tool
<tb><SEP> of <SEP> the sample <SEP> microrelief
<tb><SEP> tillon, <SEP> mm
<tb><SEP> Of course
<tb><SEP> d <SEP> L <SEP> S1 <SEP> h <SEP> b <SEP> S <SEP>&alpha;<SEP> D <SEP> rs <SEP> Z <SEP> l1 <SEP> l / s
<tb><SEP> 1 <SEP> 2 <SEP> 3 <SEP> 4 <SEP> 5 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 10 <SEP> 11 <SEP> 12 <SEP> 13 <SEP> 14
<tb><SEP> 219 <SEP> 81 <SEP> 30 <SEP> 50 <SEP> 1.2 <SEP> 0.005 <SEP> 2 <SEP> 6.5 <SEP> 2 26 '<SEP> 50 <SEP> 1.0 <SEP> 1 <SEP> 13 <SEP> 24
<tb><SEP> 220 <SEP> 81 <SEP> 30 <SEP> 50 <SEP> 1.4 <SEP> 0.005 <SEP> 2 <SEP> 1.5 <SEP> 2 26 '<SEP> 50 <SEP> 1.0 <SEP> 1 <SEP> 78.5 <SE> 105
<tb><SEP> 221 <SEP> 81 <SEP> 30 <SEP> 50 <SEP> 2.3 <SEP> 0.005 <SEP> 2 <SEP> 3.3 <SEP> 2 26 <SEP> 50 <SEP> 1.0 <SEP> 2 <SEP> 39.5 <SEP> 24
<tb><SEP> 222 <SEP> 82 <SEP> 50 <SEP> 100 <SEP> 3.6 <SEP> 0.005 <SEP> 5 <SEP> 6.3 <SEP> 3 39 '<SEP> 1200 <SEP> 2.5 <SEP> 1 <SEP> 1568 <SEP> 600
<tb><SEP> 223 <SEP> 82 <SEP> 50 <SEP> 100 <SEP> 5.5 <SEP> 0.030 <SEP> 6 <SEP> 5.8 <SEP> 4 21 <SEP> 300 <SEP> 1.5 <SEP> 1 <SEP> 471 <SEP> 162
<tb><SEP> 224 <SEP> 82 <SEP> 50 <SEP> 100 <SEP> 5.6 <SEP> 0.030 <SEP> 6 <SEP> 9.7 <SEP> 4 21 <SEP> 300 <SEP> 1.5 <SEP> 4 <SEP> 78.5 <SEP> 24.2
<tb><SEP> 225 <SEP> 82 <SEP> 50 <SEP> 100 <SEP> 37.4 <SEP> 0.030 <SEP> 20 <SEP> 38.3 <SEP> 4 21 <SEP> 300 <SEP> 1.5 <SEP> 1 <SEP> 868.5 <SEP> 24
<tb><SEP> 226 <SEP> 83 <SEP> 200 <SEP> 300 <SEP> 12.2 <SEP> 0.050 <SEP> 20 <SEP> 19.5 <SEP> 3 39 '<SE> 600 <SEP> 2.0 <SEP> 4 <SEP> 157 <SEP> 24
<tb><SEP> 227 <SEP> 83 <SEP> 200 <SEP> 300 <SEP> 12.4 <SEP> 0.050 <SEP> 20 <SEP> 13.4 <SEP> 3 39 '<SE> 600 <SEP> 2.0 <SEP> 1 <SEP> 942 <SEP> 140
<tb><SEP> 228 <SEP> 83 <SEP> 200 <SEP> 300 <SEP> 77.5 <SEP> 0.050 <SEP> 20 <SEP> 78.3 <SEP> 3 39 <SEP> 600 <SEP> 2.0 <SEP> 1 <SEP> 1727 <SEP> 24
<tb><SEP> 229 <SEP> 84 <SEP> 800 <SEP> 1000 <SEP> 15.6 <SEP> 0.100 <SEP> 30 <SEP> 21.7 <SEP> 1 22 '<SEP> 1200 <SEP> 2.5 <SEP> 1 <SEP> 314 <SEP> 173
<tb><SEP> 230 <SEP> 84 <SEP> 800 <SEP> 1000 <SEP> 39.8 <SEP> 0.100 <SEP> 30 <SEP> 52 <SEP> 1 22 '<SEP> 1200 <SEP> 2.5 <SEP> 1 <SEP> 942 <SEP> 72.8
<tb><SEP> 231 <SEP> 84 <SEP> 800 <SEP> 1000 <SEP> 157 <SEP> 0.100 <SEP> 30 <SEP> 157 <SEP> 1 22 '<SEP> 1200 <SEP> 2, 5 <SEP> 1 <SEP> 3454 <SEP> 24
<tb> Table 21 (continued)

<SEP> Dimensions <SEP> obtained <SEP> from <SEP> microrelief
<tb><SEP> 1 / <SEP> D <SEP> h1 <SEP> n3 <SEP> S0 <SEP> S '<SEP> h <SEP> b <SEP> S <SEP>&alpha;;
<tb><SEP> 1 <SEP> 15 <SEP> 16 <SEP> 17 <SEP> 18 <SEP> 19 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23 <SEP> 24
<tb><SEP> 219 <SEP> 1/12 <SEP> 7643 <SEP> 318 <SEP> 4 <SEP> 10 <SEP> 1.2 <SEP> 0.005 <SEP> 2.0 <SEP> 6, 5 <SEP> 2.5
<tb><SEP> 220 <SEP> 1/2 <SEP> 7643 <SEP> 76.4 <SEP> 4 <SEP> 10 <SEP> 1.4 <SEP> 0.005 <SEP> 2.0 <SEP> 1.6 <SEP> 2.5
<tb><SEP> 221 <SEP> 1/2 <SEP> 7643 <SEP> 318 <SEP> 4 <SEP> 10 <SEP> 2.2 <SEP> 0.005 <SEP> 2.0 <SEP> 3, 3 <SEP> 2.5
<tb><SEP> 222 <SEP> 5/12 <SEP> 769 <SEP> 31.8 <SEP> 10 <SEP> 5 <SEP> 3.6 <SEP> 0.005 <SEP> 5.0 <SEP> 6.2 <SEP> 3.5
<tb><SEP> 223 <SEP> 1/2 <SEP> 2230 <SEP> 14 <SEP> 12 <SEP> 12 <SEP> 5.3 <SEW> 0.030 <SEW> 6.0 <SEP> 5, 7 <SEP> 4,5
<tb><SEP> 224 <SEP> 1/12 <SEP> 1273 <SEP> 53 <SEP> 12 <SEP> 12 <SEP> 5.6 <SEP> 0.030 <SEP> 6.0 <SEP> 9, 8 <SEP> 4,5
<tb><SEP> 225 <SEP> 11/12 <SEP> 1273 <SE> 53 <SEP> 12 <SEP> 10 <SEP> 37.3 <SEP> 0.030 <SE> 20.0 <SE> 38, 2 <SEP> 4,5
<tb><SEP> 226 <SEP> 1/12 <SEP> 637 <SEP> 26.5 <SEP> 40 <SEP> 20 <SEP> 12.2 <SEP> 0.050 <SEP> 20.0 <SEP> 19.5 <SEP> 3.5
<tb><SEP> 227 <SEP> 1/2 <SEP> 1115 <SEP> 7.0 <SEP> 40 <SEP> 20 <SEP> 12.4 <SEP> 0.050 <SEW> 20.0 <SEP> 13.3 <SEP> 3.5
<tb><SEP> 228 <SEP> 11/12 <SEP> 637 <SEP> 26.5 <SEP> 40 <SEP> 20 <SEP> 77.4 <SEP> 0.050 <SEP> 20.0 <SEP> 78.2 <SEP> 3.5
<tb><SEP> 229 <SEP> 1/12 <SEP> 557 <SEP> 3.2 <SEP> 60 <SEP> 35 <SEP> 15.6 <SEP> 0.100 <SEP> 30.0 <SEP> 21.6 <SEP> 1.5
<tb><SEP> 230 <SEP> 1/2 <SEP> 478 <SEP> 13.2 <SEP> 60 <SEP> 35 <SEP> 39.8 <SEP> 0.100 <SEP> 30.0 <SEP> 52.0 <SEP> 1.5
<tb><SEP> 231 <SEP> 11/12 <SEP> 318.4 <SEP> 13.2 <SEP> 60 <SEP> 60 <SEP> - <SEP> Corrugated <SEP> Groove
<tb><SEP> 0.100 <SEP> 30.0 <SEP> 137 <SEP> 1.5
<Tb>
Examples 232-244
Chromium-nickel steel samples with a carbon content of approximately 0.12% and a surface hardness of 60 HRC were machined. As the shape and dimensions of the samples were similar to those shown in Examples 219-231, machining was performed as described in the same examples using the same tools and equipment.

 The predetermined dimensions of the microrelief, the dimensions of the tools and the machining rates were as in Examples 219-231.

 Microreliefs were obtained, the dimensions of which, for each of the samples, are collated in Table 22 and appear in the same order of succession as in Table 21.

Table 22

<tb><SEP> Dimensions <SEP> obtained <SEP> from
<tb> N <SEP> Type <SEP> microrelief
<tb> Sample <SEP> Sample <SEP> No <SEP> Angle
<tb><SEP> ple <SEP> tillon <SEP> Of course, <SEP> mm <SEP> sircu- <SEP> of elevated
<tb><SEP> Lon- <SEP> Profon- <SEP> Lar- <SEP> laire, <SEP> tion <SEP> of
<tb><SEP><SEP> seur <SEP> geur <SEP> n <SEP><SEP> The <SEP> line
<tb><SEP> helicol- <SEP>
<tb><SEP> h <SEP> b <SEP> S <SEP> @@@@ &alpha;<SEP><SEP>%
<tb><SEP> 1 <SEP> 2 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23 <SEP> 24
<tb> 232 <SEP> 85 <SEP> 1.2 <SEP> 0.005 <SEP> 2.0 <SEP> 6.6 <SE> 2.5
<tb> 233 <SEP> 8S <SEP> 1.4 <SEP> 0.005 <SEP> 2.0 <SEP> 1.6 <SEP> 2.5
<tb> 234 <SEP> 85 <SEP> 2,3 <SEP> 0.005 <SEP> 2.0 <SEP> 3.3 <SEP> 3.5
<tb> 235 <SEP> 86 <SEP> 3.6 <SEP> 0.030 <SEP> 5.0 <SEP> 6.3 <SEP> 4.5
<tb> 236 <SEP> 86 <SEP> 5.4 <SEP> 0.030 <SEP> 6.0 <SEP> 5.8 <SEP> 4.5
<tb> 237 <SEP> 86 <SEP> 5.7 <SEP> 0.030 <SEP> 6.0 <SEP> 9.9 <SEP> 4.5
<tb> 238 <SEP> 86 <SEP> 37.5 <SEP> 0.050 <SEP> 20.0 <SEP> 38.4 <SEP> 3.5
<tb> 239 <SEP> 87 <SEP> 12.2 <SEP> 0.050 <SEP> 20.0 <SEP> 19.6 <SEP> 3.5
<tb> 240 <SEP> 87 <SEP> 12.4 <SEP> 0.050 <SEP> 20.0 <SEP> 13.4 <SEP> 3.5
<tb> 241 <SEP> 87 <SEP> 77.5 <SEP> 0.050 <SEP> 78.3 <SEP> 78.3 <SEP> 1.5
<Tb>
Table 22 (continued)

<tb><SEP> 1 <SEP> | <SEP> 2 <SEP> 2 <SEP> j <SEP> 20 <SEP> j <SEP> 21 <SEP> 1 <SEP> 22 <SEP>#<SEP> 23 <SEP> 23 <SEP>#<SEP><SEP> 24
<tb> 242 <SEP> 88 <SEP> 15.6 <SEP> 0.100 <SEP> 30.0 <SEP> 21.7 <SEP> 1.5
<tb> 243 <SEP> 88 <SEP> 39.8 <SEP> 0.100 <SEP> 30.0 <SEP> 52.1 <SEP> 1.5
<tb> 244 <SEP> 88 <SEP> wavy <SEP> groove
<tb><SEP> 0.100 <SEP> 30.0 <SEP> 157 <SEP> 1.5
<Tb>
The difference between the dimensions obtained and those which had been planned was within the limits of the allowed difference. The surface between the recesses did not differ from the original surface.

EXAMPLES 245-257
Tin-fluorine bronze specimens were machined, the dimensions and shape of which were similar to those given in Examples 219-231.

For this purpose we used grinding wheels whose construction did not differ from that given in the same examples. The material of the inserts was the black silicon carbide (more than 95 SiC) granuloetie 160-200 / m, dispersed in a ceramic binder.

 In Examples 250-255, work was performed using grinders with radially adjustable working elements 26 (FIGS. 23-25).

 The predetermined dimensions of the microrelief, the dimensions of the tools and the machining rates were as in Examples 219-231.

 Microreliefs were obtained, the dimensions of which for each of the samples are shown in Table 23 and appear in the same order of succession as the similar data in Table 21.

Table 23

<tb><SEP><SEP> Sizes <SEP> of the <SEP> microrelief <SEP>
<tb><SEP> N <SEP> Type
<tb><SEP> of exem- <SEP> of exchange <SEP> Evidence <SEP> Pas <SEP> Angle
<tb><SEP> ple <SEP> tillon <SEP> circu <SEP> of elevated
<tb><SEP> Lon- <SEP>#<SEP><SEP> Profon- <SEP> Lar- <SEP> laire, <SEP> tion
<tb><SEP> deur, <SEP> deur, <SEP><SEP> geur, <SEP> of <SEP> la
<tb> mm <SEP> mm <SEP> mm <SEP> mm <SEP> line
<tb><SEP> Helicopter
<tb><SEP> dale
<tb><SEP> S1 <SEP> h <SEP> b <SEP> S <SEP>&alpha;<SEP>
<tb> I <SEP> 1 <SEP> 2 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23 <SEP> 24
<tb><SEP> 245 <SEP> 89 <SEP> 1.3 <SEP> 0.005 <SEP> 2.0 <SEP> 6.5 <SE> 2.5
<tb><SEP> 246 <SEP> 89 <SEP> 1.5 <SEP> 0.005 <SEP> 2.0 <SEP> 1.5 <SEP> 2.5
<tb><SEP> 247 <SEP> 89 <SEP> 2.4 <SEP> 0.005 <SEP> 2.0 <SEP> 3.4 <SEP> 3.5
<tb><SEP> 248 <SEP> 90 <SEP> 3.7 <SEP> 0.030 <SEP> 5.0 <SEP> 6.3 <SEP> 4.5
<tb><SEP> 249 <SEP> 90 <SEP> 5.4 <SEP> 0.030 <SEP> 6.0 <SEP> 5.8 <SEP> 4.5
<tb><SEP> 250 <SEP> 90 <SEP> 5.7 <SEP> 0.030 <SEP> 6.0 <SEP> 9.8 <SEP> 4.5
<tb><SEP> 251 <SEP> 90 <SEP> 37.5 <SEP> 0.050 <SEP> 20.0 <SEP> 38.1 <SEP> 3.5
<tb><SEP> 252 <SEP> 91 <SEP> 12.3 <SEP> 0.050 <SEP> 20.0 <SEP> 19.4 <SEP> 3.5
<tb><SEP> 253 <SEP> 91 <SEP> 12.5 <SEP> 0.050 <SEP> 20.0 <SE> 13.4 <SEP> 3.5
<tb><SEP> 254 <SEP> 91 <SEP> 77.6 <SEP> 0.050 <SEP> 20.0 <SE> 78.3 <SE> 1.5
<tb><SEP> 255 <SEP> 92 <SEP> 15.7 <SEP> 0.100 <SEP> 30.0 <SEP> 21.8 <SEP> 1.5
<tb><SEP> 256 <SEP> 92 <SEP> 39.9 <SEP> 0.100 <SEP> 30.0 <SEP> 52.0 <SEP> 1.5
<tb><SEP> 257 <SEP> 92 <SEP> Corrugated <SEP> groove
<tb><SEP> 0.100 <SEP> 30.0 <SEP> 157.0 <SEP> 1.5
<Tb>
The difference between the dimensions obtained and those which had been planned was within the limits of the allowed difference. The surface between the recesses did not differ from the original one.

Examples 258-270
Nickel-chromium cast iron samples with a surface hardness of 675 HB were machined, the shape and dimensions of which were the same as in Examples 219-231. The machining was performed using grinding wheels whose construction was similar to that described in the same examples. The material of the insertion parts was green silicon carbide (more than 97% SiC), with a particle size of 160-200 m, dispersed in a ceramic binder.

 In Examples 264-269, machining was performed using grinders with radially adjustable work elements 26 (see Figs. 23-25).

 The predetermined dimensions of the microrelief, the dimensions of the tools and the machining rates repeated those given in Examples 219-231.

 Microreliefs were obtained, the dimensions of which, for each of the samples, are collated in Table 24 and appear in the same order of succession as the similar data in Table 21.

Table 24

<tb><SEP><SEP> Sizes <SEP> of the <SEP> microrelief <SEP>
<tb> Type
<tb><SEP> of exem- <SEP> of exchange <SEP> Evidence, <SEP> mm <SEP> Pas <SEP> Angle
<tb> ple <SEP> tillon <SEP> circu <SEP> of elevated
<SEP> Lon- <SEP> Profon- <SEP> lar- <SEP> laire <SEP> tion <SEP> of
<tb><SEP> for <SEP><SEP><SEP><SEP> line
<tb><SEP> Helicopter
<tb><SEP> S1 <SEP> h <SEP> b <SEP> S <SEP> dale
<tb><SEP> 1 <SEP> 2 <SEP> 20 <SEP> 21 <SEP> 22 <SEP> 23 <SEP> 24
<tb><SEP> 258 <SEP> 93 <SEP> 1.2 <SEP> 0.005 <SEP> 2.0 <SEP> 6.4 <SEP> 2.5
<tb><SEP> 259 <SEP> 93 <SEP> 1.4 <SEP> 0.005 <SEP> 2.0 <SEP> 1.6 <SEP> 2.5
<tb><SEP> 260 <SEP> 93 <SEP> 2,3 <SEP> 0.005 <SEP> 2.0 <SEP> 3.2 <SEP> 3.5
<tb><SEP> 261 <SEP> 94 <SEP> 3.6 <SEP> 0.030 <SEP> 5.0 <SEP> 6.2 <SEP> 4.5
<tb><SEP> 262 <SEP> 94 <SEP> 5.2 <SEP> 0.030 <SEP> 6.0 <SEP> 5.8 <SEP> 4.5
<tb><SEP> 263 <SEP> 94 <SEP> 5.7 <SEP> 0.030 <SEP> 6.0 <SEP> 9.7 <SEP> 4.5
<tb><SEP> 264 <SEP> 94 <SEP> 37.5 <SEP> 0, Q50 <SEP> 20, C <SEP> 38.3 <SEP> 3.5
<tb><SEP> 265 <SEP> 95 <SEP> 12.3 <SEP> 0.050 <SEP> 20.0 <SEP> 19.6 <SEP> 3.5
<tb><SEP> 266 <SEP> 95 <SEP> 12.5 <SEP> 0.050 <SEP> 20.0 <SEP> 13.4 <SEP> 3.5
<tb><SEP> 267 <SEP> 95 <SEP> 77.6 <SEP> 0.050 <SEP> 20.0 <SEP> 78.3 <SEP> 1.5
<tb><SEP> 268 <SEP> 96 <SEP> 15.6 <SEP> 0.100 <SEP> 30.0 <SEP> 21.7 <SEP> 1.5
<tb><SEP> 269 <SEP> 96 <SEP> 39.8 <SEP> 0.100 <SEP> 30.0 <SEP> 52.0 <SEP> 1.5
<tb><SEP> wavy <SEP> groove
<tb><SEP> 270 <SEP> 96 <SEP> 0.100 <SEP> 30.0 <SEP> 157.0 <SEP> 1.5
<Tb>
The difference between the dimensions obtained and those which had been predicted was within the limits of the allowed gap. The area between the recesses did not differ from the original one.

 The dimensions of the microreliefs shown in Tables 1-24 are each the arithmetic mean of the measurements made on ten samples of the same type.

 Among the embodiments described above, of the method according to the invention the preferred embodiments are those which provide for the rotation of the axis of the wheel around an immobile axis parallel to this denier, and whose implementation requires the use of a tool head, and those providing the use of a grinding wheel whose cutting surface has a plurality of separate portions arranged at a certain pitch along the periphery of the grinding wheel. As can be seen from the descriptions of the embodiments in question, these do not require significant expense because they can be implemented with the help of a low-cost material. The flat and cylindrical grinding machines of the known type are perfectly suitable for this purpose.

 The comparison of the data in Tables 1-8 with those presented in Tables 9-16, the two groups of tables being for samples of the same type, shows that the effect of the continuous displacement of the sample length of the recesses obtained during machining is relatively small (it can be considered analytically), hence the possibility, whenever the need arises, of to obtain a regular microrelief by animating the piece with a continuous translation movement.

It is obvious that this form of movement is easier to obtain, and therefore more advantageous, because it can be achieved using the table of a machine tool without resorting to a special device provided with a mechanism of movement step by step.

 By comparing the data in Tables 1-4, 5-8, 9-12, 13-16, 17-20 and 21-24 illustrating the results of machining sample pieces whose dimensions and machining were similar, we see that a good choice of the material of the grinding wheel makes it possible to overcome all-i-iait effectively the effect of the material of the parts on the dimensions of the microrelief to obtain. In the variant of machining envisaging the use of a grinding wheel whose portions of the cutting surface are arranged at a certain pitch, this effect is hardly felt and is explained, in the case of hard parts, by the high load acting on the abrasive grains hence faster wear of the grinding wheel and, inevitably, a change in the dimensions of the microrelief.

 The given embodiments of the method of the invention highlight the fact that the areas of application of grinding wheels whose portions of the cutting surface are arranged in a certain pitch and tool heads are only partly identical. . Normally> when it comes to small parts that must be provided with a shallow microrelief, it is preferable to use grinding wheels whose portions of the cutting surface are arranged in a certain step, while the tool heads are reserved for larger pieces and in case the microrelief to be obtained must be deeper.

 Another distinction in the fields of application of the described embodiments of the invention stems from the shape of the recesses to be obtained.

 When machining workpieces using tool heads, recesses in the form of circular segments of a very large radius (larger than the radius of the tool head itself) are obtained. Thus, the profile of the recesses obtained in this way is characterized by low elevation angles (in all the drawings where the profile of the recesses is indicated, this angle is designated by the symbol g). This kind of microrelief is of particular interest in this type of friction assembly, which must be the seat of a maximum hydrodynamic effect, when the consequences of this effect (rise of one of the friction surfaces above the other) do not interfere with the operation of the assembly in question Normally, these characteristics are very much sought after in fluid bearings used in the spindles of machine tools and in friction assemblies with a sliding speed greater than 1 m / s.

 When machining the surfaces using grinding wheels whose portions of the cutting surface are arranged at a certain pitch, rounded recesses are obtained at a smaller radius. By choosing grinding wheels with a larger length 11 of the portion. of the cutting surface, relatively long recesses can be obtained (for more details, compare the vertical columns 15 and 2 of Table 17) and, consequently, oil pockets with a larger capacity than the pockets of the same depth but obtained by machining using tool heads. This is precisely why the wheels in question are preferred when seeking to obtain oil pockets on a friction surface whose hydrodynamic effect is considered limited, but whose power of oil stoppage should be maximum. These characteristics are especially sought after when it comes to the flat slideways of machine tools, where raising the carriage under the hydrodynamic effect is detrimental to the precision of the machining.

 it should be noted that the method described above allows to obtain recesses t elevation angle provided in the machining direction as well as in the transverse direction. It is sufficient for this purpose to cut the grinding wheel so that its cutting surface has in cross section the desired curvilinear profile (see Figure 33).

 The method in question makes it possible to obtain a regular microrelief practically on any surface of the metal parts without taking into account their dimensions and the properties of the metal of which they are made. The roughness of the surface, at the places between the recesses, remains the same as that of the starting surfaces or, in the case of wheels with elastic plates, decreases.

 Among the advantages of the process according to the invention, an important place is its economic nature and its high efficiency.

 In addition to the process applications mentioned above, others may be mentioned, such as, for example, machining surfaces of cold rolled parts to increase their rigidity and strength; machining the working surfaces of the measuring gauges to increase their strength and stopping power; machining other parts in cases where the presence of a regular microrelief on their surface improves their wear resistance and other required characteristics.

 The process according to the invention also makes it possible to obtain a microrelief on the surface of non-metallic parts made of materials such as, for example, glass, marble, plastics and others. The microrelief obtained on these surfaces normally plays a decorative role.

 Of course, the invention is in no way limited to the embodiments described and shown which have been given by way of example only. In particular, it includes all the means constituting technical equivalents of the means described and their combinations, if they are executed according to its spirit and implemented in the context of protection as claimed.

Claims (22)

 1. A method of forming on the surface of a workpiece, a regular microrelief composed of separate recesses, of the type consisting in moving the tool and the workpiece relatively to one another, parallel to the surface to be machining, characterized in that the regular microrelief is obtained by grinding by means of a grinding wheel (1) in rotation which periodically acts, by its peripheral cutting surface, on the surface to be machined (2) of the piece (3 ), said grinding wheel being arranged so that its plane of rotation is oriented substantially in the direction of the mentioned relative displacement.  2. A process according to claim 1, characterized in that, during the formation of a microrelief on the surface of a workpiece in the form of a body of revolution, said workpiece is rotated and advanced axially, which ensures the relative movement of the grinding wheel and the workpiece parallel to the surface to be machined in two directions, said grinding wheel being arranged so that its rotational plane coricates substantially with the plane of rotation of the workpiece.  3.- Method according to one of claims 1 and 2, characterized in that the periodic action of the cutting surface of the grinding wheel on the surface to be machined is obtained by relative oscillation of the workpiece and the grinding wheel in the plane of rotation thereof and in a direction substantially perpendicular to the surface of the workpiece at the machining location.  4. A method according to claim 3, characterized in that the periodic action of the cutting surface of the grinding wheel on the surface to be machined is exerted during pauses or interruptions relative movement of the grinding wheel and the piece parallel to the surface to be machined, said relative displacement having an intermittent character.  5. A process according to claim 3, characterized in that said oscillatory movement is carried out simultaneously with the relative movement of the part and the grinding wheel parallel to the surface to be machined, said displacement having a continuous character.  6. A process according to one of claims 7 and 2, characterized in that the periodic action of the cutting surface of the grinding wheel on the surface to be machined is obtained by rotating the axis of the grinding wheel around a fixed axis parallel to it.  7. A method according to claim 6, characterized in that the relative displacement parallel to the surface to be machined is obtained by corresponding intermittent movement of the workpiece at a speed related to the speed of rotation of the axis of the wheel, so that it acts on the part during the stops of the latter.  8. A process according to claim 6, characterized in that the relative displacement parallel to the surface to be machined is obtained by continuous movement of the workpiece.  9.- Method according to one of claims 1 and 2, characterized in that the periodic action on the surface to be machined de -the part is exerted, the axis of rotation of the grinding wheel being fixed by the cutting surface of the latter composed of individual portions arranged at a certain pitch along the periphery of the grinding wheel.  10. A tool head for the formation of a regular microrelief according to the method according to claim 6, of the type intended to be mounted on a machine tool for machining metals by cutting, characterized in that it comprises a plate adapted to be fixed in the spindle of the machine tool, wheels movable in rotation arranged regularly around the periphery of said plate and having a peripheral cutting surface, rigid planet wheels rigidly connected to the wheels and a coaxial central gear said plate gear and meshing with the planet gears, said central gear being adapted to be fixed on the stationary part of the machine tool.  11. A tool head according to claim 10, characterized in that the distance between the wheels of the axis of rotation of the plate is such that the diameter of the circumference described around said grinding wheels and passing through the points of their surfaces of cut farthest from their own axes of rotation shall not be less than 200 s.  12. A tool head according to one of claims 10 and 11, characterized in that the number of grinding wheels does not exceed four.  13. - Tool head according to one of claims 10 and 12, characterized in that the edges of the cutting surface of each of the wheels are rounded in WL radius of 1 to 3 mm.  14.- Grinding wheel for the formation of a regular microrelief on the surface of a workpiece according to the process according to claim 9, characterized in that it comprises working elements comprising portions of the cutting surface of the grinding wheel. , which portions are arranged at a certain pitch along the periphery of the latter, the plane sectioning said grinding wheel perpendicular to its axis of rotation comprising said portions of 1 to 4, the length of which is not greater. at 11/12 of the length of the periphery of the cutting surface, and the pitch of said portions following said circumference depend on the prescribed pitch S of the microrelief along the surface to be machined, said pitch being in the range of 245 to 6005 .  15. Wheel according to claim 14, characterized in that the diameter D of the circumference passing through the points furthest from its axis of rotation is not less than 50 mm.  16. Wheel according to claim 15, characterized in that to obtain a depth of the microrelief greater than 0.005 mm, the diameter D has a value not less than that resulting from the formula  D = 100 [1 + (h - 0.01) 700 m where h is the predetermined depth of the microrelief to be obtained.  17.- Grinding wheel according to one of claims 14 to 16, characterized in that the cutting surface of each of its working elements has in cross section of the lateral roundings with a radius of 1 to 3 mm.  18.- Grinding wheel according to one of claims 14 to 17, characterized in that its work elements are abrasive insertion parts mounted on a tray.  19. Wheel according to claim 18, characterized in that in the case of insertion pieces arranged in several rows along the periphery of the plate, the insertion parts forming an annular row in a plane perpendicular to the axis of rotation of the grinding wheel, are displaced circumferentially with respect to the insertion parts of the adjacent row.  20.- Grinding wheel according to one of claims 18 to 19, characterized in that it comprises sliders mounted in the tray and on which are fixed the working elements, the arrangement of said sliders can be set radially, a ring limb mounted rotatably in the center of the plate, coaxially with the cutting surface, and hinge elements each of which is connected by one of its ends to said ring, and by their other end, to one sliders.  21.- Grinding wheel according to one of claims 18 and 19, characterized in that the plate is made of an elastic abrasive material whose grains are smaller than those of the abrasive insertion parts, and in that it has radial housings receiving said insertion pieces and corresponding thereto in shape and depth, so that said insertion pieces and the plate together form a continuous peripheral cutting surface.  22.- Parts, products or articles characterized in that they are treated in accordance with the method forming the subject of one of claims 1 to 9.