MXPA96005141A

MXPA96005141A - Procedure and device for continuous separation without chip of individual rings removal tubula

Info

Publication number: MXPA96005141A
Application number: MXPA/A/1996/005141A
Authority: MX
Inventors: Feldmeier Fritz
Original assignee: Feldmeier Fritz Dr 90475 Nuernberg De
Priority date: 1994-04-29
Filing date: 1995-04-27
Publication date: 1998-07-03

Abstract

The present invention relates to a process for the continuous separation without chip removal of identical individual rings from tubular workpieces by means of three cutting rollers with threaded blades which are driven in the same direction and press on the surface of the tubular workpiece and thus winding around, so that the relative positions of rotation of the three cutting rollers are adjusted so that the contact of the blades on the workpiece to be cut takes place in a plane of exact common separation, and the diameter of the cutting rollers increases from start to finish so that a narrow channel is formed, whereby the tubular workpiece is rotated in a direction opposite to that of the cutting rollers and is axially advanced, a process characterized in that after a phase of entry of the centering of the section to be cut from the workpiece tub ular, which when viewed longitudinally is completely surrounded by the longitudinal contour of the cutting rollers, without any interruption of the contact line between the workpiece and the cutting rollers during the entire separation process and with the application of large partially perpendicular forces axial forces on the fornibal surfaces and partially radial forces on the surface area of the box, rings with parallel frontal surfaces are produced that are perpendicular to the axis of the workpiece, and before the separation process, the workpiece The tubular material is heated to a temperature that substantially reduces the resistance to the formation of the material used, which results in a higher temperature on the outer surface than on the inner surface of the tubular workpiece.

Description

PROCEDURE AND DEVICE FOR CONTINUOUS SEPARATION WITHOUT CHIP OF INDIVIDUAL RINGS FROM TUBULAR PARTS DESCRIPTION The invention relates to a process for the continuous separation without shavings of individual rings that are equal to one another of tubular work pieces, according to the main idea of the claim. Annular construction parts are widely known in the art. In the rolling technique they represent a significant amount and even a very essential fraction of the parts; In a known manner, each bearing consists of at least two annular components forming the inner ring and the outer ring. These rings are obtained in a large number of parts, for example, from a tabular partial stretch made of bearing steel the division of the tabular material into rings of the same size, it is especially in the manufacture of bearings a standard manufacturing step, that with the increasing competition in the bearing branch has acquired an outstanding significance, as it is to reach a higher productivity and favorable manufacturing costs, this step of manufacture reaches a very important meaning, where first of all, the separation with shavings of the expensive material increases the high costs. A method of this kind for the chipless separation of individual rings from one another, from tubular workpieces, is published in the German patent document DE-OS 1602950. In this process three cutting rollers are arranged with blades in the form of thread around the piece to be processed, these cutting blades are driven in the same direction and pressed on the surface of the piece. The tabular part rotates in the opposite direction to the cutting rollers and moves axially, the position of rotation between the three cutting rollers is directed in such a way that the cutting contact with the piece to be divided takes place in a Cutting plane exactly common. The diameter of the cutting rollers increases from the beginning to the end and thus forms a channel that narrows. This device is not suitable for manufacturing bearing rings with high accuracy, since the area of the front surface of the separated rings are strongly rounded. In addition, the blades of the cutting rollers wear out rapidly, since the steel of the bearings have a high resistance to forming and no measures can be provided for the reduction of that resistance to deformation. Another method for the division of the tabular material is known from the German patent document DE-PS 1013487. In this process, a retaining head runs around the pipe to be separated, which has a retainer in a transverse plane. of piece arranged in the periphery, and there presents cutting rollers mounted loosely. The cutting rollers are provided with blades on radially essential flanks, which are brought into contact on the front side with the tube to be separated during the separation process. With this method, only discontinuous individual tubular sections can be separated, the device is not suitable for separating the short periods of action equal rings from each other, continuously from the tabular material. It is the task of the present invention to create a process for the continuous separation without presenting chip of individual rings equal to each other, from tubular pieces, whereby it is feasible to preferably manufacture rings from bearing steel with high accuracy, so that disappear either completely a further processing with chips < _ this processing with shavings is negligible, and that hot laminated tube can be used directly if previous thermal treatment. Another objective consists in that in the elaboration 1 bearing steel a high durability of the tool is achieved. That task, it is solved with the patent of the claim, others formed as a device for the redeeming embodiment are indicated in other claims. Unlike the known state of the separation process technician, the tabular part that is to be heated to a very low temperature cor. ration to the deformation resistance of the low p df used. The heating temperature can change values around 800 ° and more; The exact temperature is governed by the molding and ignition behavior of the material used, the operation data of the day, the separation time, the material as well as the dwell time that the cutting rollers were looking for. Another property characteristic of the process according to the invention is the manufacture or obtaining of frontal surfaces in the separated rings that are parallel to the plane and perpendicular to the axis of the workpiece. This has great advantage, especially for the manufacture of bearing rings, the more accurate the flat surfaces obtained by the separation, the smaller the expense in the subsequent work required, for example, in the form of a pre-polishing parallel to the plane. The entry phase or central start before the separation process itself, has been presented as an advantageous manufacturing, since, in this way it is possible to produce tubular workpieces with a large tolerance amplitude. With this, it is also possible to produce, for example, directly hot-rolled tubes without taking into account the tolerances before a cold forming, for example, in the cold pilgrim's step or cold drawing. This possibility of using hot-rolled tubes greatly increases the economy of the process. In order to obtain a contour as accurately as possible of the separated rings, the penetration movement of the cutting rollers in the material of the tabular part to be worked is directed, in all points exactly radially towards the axis of the piece. of tabular work. The forces of deformation, are forces of pressure and act during the entire separation process always exactly perpendicular to the surface of the workpiece. The rings that have to be separated, the more they move towards the final mold or shape of the separation process, they are enclosed if seen in a longitudinal cut completely by the longitudinal contour of the cutting rollers, without interruption of the touch line between the work piece and the cutting rollers, during the entire separation process. The tubular sections receive the application of high normal forces, once axial forces on the frontal surfaces and on the other hand radial forces on the surface of the jacket. These normal forces. they are pure pressure forces, and exclusively generate pressure stresses in the contact areas with the cutting rollers which also prevents a lateral leakage in flow of the material due to the lateral mold limitation caused by the flanks of the cutting edges. Thanks to the enclosure on three sides of the rings during the separation, they obtain the rings thanks to the force effect of a single effect, a good and constant contour accuracy. Another characteristic refers to the profile of the temperature in the tabular piece to be divided; According to the present invention, a higher temperature is generated on the outer surface of the workpiece to be separated than on the inner surface, in the cold edge layer, the material will consequently have a higher resistance, this strengthens the resistance to deformation against compression of the tabular part by the radial forces produced by the cutting rollers and the pressure stress in the material increases. This effect acts positively for the process since the pressure stresses mentioned increase more in the material, and this greatly improves the accuracy of shape and measurement. A somewhat harder edge layer of the perforation wall also prevents the formation of burrs, and thereby improves the separation of the rings. Another additional striking device as mentioned in the current state of the art is therefore no longer necessary for the method according to the invention. The established temperature gradient allows, in most cases, to dispense with an internal support of the tabular piece that is to be separated, which simplifies in an essential way all the construction. The heating of the tabular part is mainly carried out inductively, since then the penetration depth of the heating can be regulated by the frequency; depending on the front advance, the wall thickness and the material, it may become necessary to preheat, for example, by means of a muffle furnace or also called a box furnace. The proposed heating of the tabular part, before the separation process, will however lead to a heating of the working space, since the surface temperature of the workpiece will be transmitted to the cutting rollers, and in addition the related separation process. with loss leads to an increase in the temperature of the work piece. In order to keep the temperature of the cutting rollers below a certain pre-set temperature value, which does not damage the resistance properties and the residence time of the material of the cutting rollers, it is therefore proposed to cool the cutting rollers from in. In addition, for the reduction of the friction forces on the outer surface of the cutting rollers, as well as in the workpiece, a combined cooling and lubrication means is applied. Another advantage, in the separation of a previously heated tabular workpiece, is that the hardness of the starting material has no influence and for example with this, a rolled tube can be used directly from the cooling bed after rolling, the The basic red-light required for the steel of the bearings can then be made in the separate individual ring, which puts the ring in a self-tension-free state. Such rings after processing in a soft state, after hardening and tempering have a very low hardening tension, the polishing that follows hardening can then be performed in exactly formed rings on a very small scale. This increases the quality of the final product and shortens the polishing times of the rings. The method according to the invention is applicable for the separation of equal rings from each other, of tubular parts, but also for the simultaneous application of a profile in the ring, for example, it can be formed together for the inner ring of a bearing the carrier slot of the balls. Another example would be the shaping of a conical surface in the collar area of the ring. To this end, the cutting rollers between the blades would be provided with a corresponding negative shape that would grow from zero from passage to step to final shape. The device according to the invention consists in a known manner of three cutting rollers with rope-shaped blades which are driven in the same direction and arranged around the tabular workpiece to be worked. Seen in a longitudinal section, the blades or cuts are provided with flanks that run essentially radially, and the width increases continuously from the entrance to the exit. This increase in width of the cuts, is necessary so that despite the increasing radial stretch of the cuts or blades, a certain proportion between the width and the height is maintained. Otherwise, the danger of breaking the cut would be presented, since too narrow a cut would not have enough cross section to absorb the forces. The contour at the base between the cuts is preferably parallel to the axis of the roller, each cutting roller presents a continuous increase in diameter from the beginning to the end, and forms as already mentioned a channel that narrows. The turning movement of the individual cutting rollers, between them must be very exactly synchronized; they must be driven at least with the same peripheral speed, which is done in the simplest manner when the axes of the three cutting rollers are coupled together by a form closure, and are driven together with a single drive shaft. As already explained above in the procedure, a part forming a funnel has been provided on the input side., this input part can be an integral constituent of the same cutting rollers, for example in the form of an arc phase, but can also be conical extending in several steps. Alternatively, it is also possible to coordinate an annular section having an arc phase before the cutting roller. The advantage of arranging an entry part has to be seen in that way variations in the tolerance of the tubular work pieces that are introduced are better juxtaposed, so that both laminated material and material that is not unidirectional can be worked directly. . Instead of the usual precision tubes, the less expensive starting materials can be influenced without affecting the quality of the final product, so that the economy will clearly increase. The movement of axial displacement of the tabular workpiece is carried out by rolling the radial flanks of the cutting rollers pressed radially on the work piece, this kinematic force is not given, however immediately by the insertion of the piece tabular in the arrangement of the tools, for this reason is provided before the laminator arrangement on the input side, a removable pushing device that acts on the tabular workpiece, this forced thrust that simultaneously puts the tabular part in a rotation in the opposite direction to the cutting rollers, it acts in the axial direction and is determined in its movement exactly by the number of rotations of the cutting rollers and the slope thereof, and also by at least one length of the cutting rollers. With this it is ensured, that after the introduction of an extra axial transport free from upset of the material of the tabular workpiece by that device, those will remain only from the rotation of the cutting rollers and by means of the axial pressure of the cutting edges. The geometry of the cutting step consists of the negative shape of the outer annular profile that will be transmitted to the ring to be separated and the lateral limitation with the flanks of the cuts for the cutting process. The annular profile is formed in the base between the cuts parallel on the axis to the roller of the cutting shaft. The geometry of the blade or cut consists of two sections, the cutting head, is formed in its maximum diameter in a known manner in the form of a point or cut to easily penetrate the material to be separated. This head, remains relatively short in reference to the joint length of the cut; the base or plant of the cut, has approximately parallel radial flanks or flanks that are inclined only varying slightly from 5o, in the form of a roof with respect to the radial plane of the cutting roller. The flanks of the cutting base laterally limit the cutting step contour; If the flanks are almost radial or start minimally from the base, they are inclined outward, that is, if the step is widened outwards, it depends on the diameter of the cutting roller of the diameter of the tabular workpiece. In a proportion equal to or greater than 3, the cutting edges should be slightly inclined outwards, with this it is achieved that the cuts or blades free of effort without wedge effect, can run in the cutting groove. In the sense of a favorable distribution of the forces produced, the proportion of diameter described will preferably be less than 3, so that the leg or base of the blade or cut is supported with almost exact radial flanks, so for a diameter of a 40mm tabular part, cutting rolls with a diameter of 100mm will be used. With this it is ensured that by the relatively steeply directed course of the blade or cut against the cutting groove in the contact area of the cutting rollers, very high axial forces will be produced for material separation, but no radial forces . The fraction of the tangential forces, which together with the axial forces represent the shear forces during the separation process, are very small and do not disrupt the course of the procedure. For the heating of the tabular part, an inductor coil is preferably disposed on the input side, through which the tabular part is driven. Depending on the frequency and the travel time, areas of the material that are closer or further away from the surface will be heated. With a certain frequency adapted to the thickness of the material to be separated and also with a suitable power of the induction heating, it can be achieved that towards the drill, the temperature is lower and that consequently the material in that area of the colder edge remains highest mechanical resistance. The contour of the cutting rollers is adjusted to the required external contour of the rings. Normally, the base of the contour is a straight line between the steps of the cutting edges with a nearly constant diameter in all the steps. However, it can alternatively also be advantageous if the diameter of the base of the contour increases slightly in the working area itself. This slight increase has the objective of reinforcing the radial pressure. In the exit area, the diameter of the base of the contour will be maintained constant, or even let go back slightly. The purpose of this is for the separated ring to have a diameter corresponding to the light width of the cutting roller arrangement in the exit area. In another case, the ring would jump if there was too strong a radial pressure, so that the range or margin of the variations in diameter would be too large. In the same sense, it is also proposed to connect a calibration section to the last cutting step in the cutting roller. This can be an integral part of the cutting rollers or be shaped as a separate annular section. This calibration section would have the advantage that, independently of the separation process, a circular roundness ring would be produced with only very small diameter alterations. On the inlet side as already mentioned, an inlet or stroke section has been provided which may be constructed, either as a short removable phase or also as a section in which the diameter of the base of the contour grows continuously towards the entrance side. This input part is advantageous to be able to also make material with large variations in the outer diameter without any kind of problem. Mainly the thread of the cutting rollers can be built in one or in several steps, in the embodiment in one step, this will be a preferred embodiment, since in this case the slope of the thread will be minimal and with this the axial thrust force acting between the cutting roller and the material can be transmitted from the most effective way When using three cutting rollers, the radial position of the processed part is always determined, so that other guide elements are left over. The diameter of the cutting roller must on the one hand have a certain proportion with respect to the diameter of the piece to be divided, but on the other hand it must have a large size. The limits are produced because large cutting rollers are not applicable, since they could interfere with each other. The ring manufacturing process according to the present invention is especially suitable in an annular outer diameter of 16 to 80 mm and a wall thickness which is approximately 8 to 15% of the outer diameter. The most favorable ratio of ring width to ring diameter is 0.2 to 0.5. This method is advantageously applicable in the manufacture of rings where the material costs form an essential part of the costs of the rings, since material losses do not occur due to the formation of shavings, and for the following processing steps can be carried out. elaborate cost-saving rings. A preferred application is the pre-processing without chips of a steel tube for bearing heated to about 800 ° turning it into rings. To carry out the process, high temperatures are required on the surface of the workpiece, which are transmitted to the cutting rollers and the work space, which heat it up considerably. By means of cooling channels in the cutting rollers, a medium with high heat absorption capacity which is pumped through a heat exchanger disposed outside the separating device is circulated. The cutting rollers consist of an internal part with the cooling channels therein worked and an outer sleeve, where the cutting profile has been made. The sleeve with the cutting profile consists of material that is insensitive to high temperature resistance, for example sintered materials or a suitable base material, which in the region of contact with the object to be separated is covered with hard material resistant to temperature. The base part and the profiled sleeve are connected in a tight and secure manner against rotation with respect to the cutting roller. By means of the drawing, both the method and the device forming part of the present invention are explained in more detail. Shown in: Figure 1 a joint arrangement of the essential parts of the device according to the invention: Figure 2 a cutting roller with a blade placed on the thread, where the diameter of the cylindrical outer contour of the roller of cutting as well as the diameter of the blade continuously grow: Figure 3 a cutting roll with an outer contour whose diameter remains the same increasing the diameter of the blade: Figure 4 a cross section of the cutting profile: Figure 4a a view of plan of the cutting profile in conjunction with the tube to be separated: Figure 5 a cutting roller with a continuously increasing slope of the separating profile: Figure 6 a longitudinal section through a cutting roller having internal cooling. Figure 1 shows the principle of the joint arrangement of the device according to the invention with its essential parts. The tube 1 to be divided is subjected to a pushing movement, heated in the induction coil 5 and inserted between the three cutting rollers 2. The three cutting rollers 2 are parallel to each other on the axis and parallel to the direction of the forward movement of tube 1 to be divided, wherein the distance of the cutting rollers 2 to the tube to be divided 1 is such that the blades 3 of the rollers 2 penetrate radially in the wall of the tube. The three cutting rollers 2 are arranged around the tube to be divided 1 forming an equilateral triangle. The three cutting rollers 2 are subjected by a drive mechanism which is not shown, to a synchronous and uniform turning movement.

This synchronous turning movement is kinematically coupled in such a way that with the axial turning movement of the tube to be divided 1, in such a way that the blades 3 placed on the cutting rollers 2 always penetrate exactly to a common plane in the tube to be divided 1. The turning movement in the same direction of the three cutting rollers 2 as well as the turning movement in the opposite direction and the forward or pushing movement of the tube 1 are indicated by arrows. As already mentioned above, the pipe is made to divide 1 additionally a turn around the own axis, which is caused by the rolling movement of the cutting rollers 2 on the pipe to be divided 1, and this leads to that in fact all the zones on the periphery of the tube to be divided 1 come into contact with the cutting rollers 2. The blades 3 do not have any constant elevation but are on the side from which the tube to be divided is introduced. 1 first completely flat, so that in this region and just penetrate into the tube to be divided 1, towards the opposite end win the blades 3 always more height, so that they always penetrate more deeply into the wall of the tube that has to divide. In the course of the movement stroke thus forced, the tube to be divided 1 will finally be divided at the other axial end of the cutting rollers 2 into separate separate rings 4. The behavior of the latter-mentioned matter is explained in more detail by means of the Figure 2 this Figure shows the common work between the tube to be divided 1 with a single cut 2. The other cutting rollers 2 that are not shown here are arranged forming a triangle around the tube i to be divided. The blade 3 is at the end of the roller 2 from where it is introduced into the tube 1 to be cut, but is only indicated very weakly. At this point, it is first of all a question that the tube 1 to be divided is securely gripped, thus supporting the rotational movement of the tube 1 and ensuring its kinematic axial movement free of problems. The blade 3 is constructed in such a way that both the diameter and the width thus increase the opposite end continuously. In certain cases, it may also be advantageous if, in the actual work area, the diameter of the contour base 6 increases slightly, but in the exit area it remains constant, as far as possible until something recoils. In this way, an elastic springing of the ring after leaving the cutting rollers 2 will be avoided. For the tube 1 to be able to cover safely due to large variations in the outer diameter, the cutting roller 2 will have an inlet part 7. In this section the diameter of the contour base 6 is greatly reduced, so that a funnel-shaped zone is produced. The contour base 6 remains in the region which is the disappearance of the cutting roller 2 resting without play on the outer wall of the tube 1 and the blade 3 always penetrates more into the tube 1 to be divided, which is finally separated into individual rings 4, which in turn have equal size with each other. The blade 3 is constructed in such a way that it both penetrates into the material and also leaves the front surfaces of the ring to be divided as flat as possible. For this reason it presents the blade 3, as shown in Figure 4. advantageously 2 section. The cutting head 8 is tipped so that it penetrates the material. On the contrary, the adjacent cutting leg or base is constructed in such a way that the flanks are widely directed perpendicularly to the axis of rotation of the cutting roller 2, so that the front surface which is thus formed of the separated rings 4 be sufficiently flat. At the end to be divided 1 is inserted into the device consists of the blade 3 exclusively of the head of cutting head 8 in the form of a tip that slowly increases slowly, where on the other hand at the opposite end of the device the blade 3 consists of the cutting leg 9. The tube to be divided is surrounded in the representation of FIG. 2 before entering the device for separating a device. retainer in the form of a tension clamp consisting of an internal part 11 and an external part 12 which can be compressed by means of an axial driving force in the likeness to a tension device being attached to the tube 1 to be divided by means of a tightening of joint forces, put in this state not only takes place the axial movement but also the turning movement of the tube to be divided 1 must the turning movement be uncoupled by means of an axial assembly here consisting of bearing movement 13 and a second axial bearing ring 14. The axial bearing ring 14 is forced by a coupling corresponding to the rotating movement of the rod. Cutting speed 2 at a kinematically correct axial displacement speed. This auxiliary position is necessary in any case when introducing a new tube 1 in the device. As the separation process proceeds, the internal part 11 and the outer part 12 of the tensioning device in the form of a tension tongs are separated from one another when the driving force is removed, they return to their starting point and are put back into place. movement when a new tube is introduced. The arresting device is shown in Figure 2 with tension clamp and an axial bearing. In fact other constructional embodiments are also possible, in Figure 3 the pushing device is represented as a rotating centered tip 15 which is centered in the tabular bore and has drive cuts of a known type. In contrast to FIG. 2, the cutting roller 20 in FIG. 3 shows a contour base 6, the diameter of which is constant over the entire length of the cutting roller. But the diameter of the blade 3 increases from one end to the other end in a known manner in a continuous manner. For the insertion of the tube 1 to be divided and for the centering the cutting roller 20 has a sliding phase 10. For example, a running notch 17 in the separate ring 16 has the base of contour 6 a negative shape corresponding 18. This negative form 18 increases towards the entry side starting with 0 continuously, until it reaches the desired final form. In difference to the pure or simple separation process, the width of the contour base 6 is continuously increased continuously to the final shape. Since a material displacement takes place due to negative form 18. The NC controlled machines make it possible to manufacture such cutting rollers 2.20 with a cutting course and a thread profile that varies continuously. Figure 4a shows a plan view of the cutting profile in connection with the tube to be separated or of the separated rings 4, this representation should clarify the continuous contact of the annular section with the cutting roller 2 for the central ring 4 said contact is indicated as contact line 19. Figure 5 essentially shows the cutting roller 2 with the continuously increasing thread slope of the blade 3. In the case of pure separation with small material displacement the width is kept constant of the contour base 6, where this width corresponds to the desired width to be separated. Since, as already mentioned for reasons of stability and mechanical strength, the blade 3 must increase in width as the radial extension grows, which is needed to fulfill the condition of a constant width of the contour base 6 that the slope of the thread grows to such an extent that the increasing width of the cut 3 is compensated exactly. In the case of an additional profiling of the separated rings with large material displacement, let the width of the contour base 6 grow continuously with the exception of the exit area, in which the degree of material displacement tends to 0 and the ring should only be calibrated. The dashed lines in Figure 5 should indicate that regardless of the selection of the width of the contour 6 the radial extension of the blade 3 continuously increases from the entrance to the exit thereby in joint action with the other two cutting rollers 2 that in that drawing is not represented a narrow channel will be formed. Figure 6 shows a cutting roller consisting of an internal part of the shaft 21 and the cutting tool 30 with blades 3. The shaft 21 has at both ends cylindrical projections 22, 23 in the form of a spigot which receive in their outer diameters the cutting roller supports in rolling positions. On the outlet side of the ring 23 is fixed the coupling part 24 which produces the rigid connection for the synchronous driving of the cutting rollers and on the input side of the cutting roller is fixed a rotatable coupling 25 on the shaft pin 22, which guarantees by means of suitable channels and perforations the circulation of the cooling agent in the rotating cutting rollers, the cooling agent circuit 26 is connected to a high-pressure pump which is not shown here as pumping the cooling agent to through the central perforation 27 in the shaft 21 through one or several radial holes 28 for the cooling channel 29 worked undulating in the outer diameter of the shaft 21. The cooling medium runs in the cooling channel, which is closed outward by the cutting tool 30, against the direction of displacement of the piece that is going to work and towards the radial exits 31 that can be one or several. These outlet perforations 31 are connected by means of one or more holes 32 through the shaft pin 22 with the outlet 33. From here the already hot cooling medium is returned to the cooling agent pump after passing by a heat exchanger. The cutting tool 30 is joined by means of contractions on the shaft 21 in a tight and secure manner for rotation therewith. In the cutting tool 30 an annular section 34 of annular shape is connected in an axial extension which once again calibrates the separated rings. The ring-shaped section 35 connecting on the input side with the cutting tool is provided with a chamfer to facilitate the center of the new tabular part that is inserted into the separating device.

Claims

CLAIMS 1.- Procedure for the continuous separation without chip detachment of individual rings equal to each other from tubular work pieces by means of three cutting rollers driven in the same direction and pressing on the surface of the tabular workpiece and there roll with threaded blades, where the position of rotation of the three cutting rollers is directed so that the cutting contact takes place towards the piece to be divided into a plane of exactly common cutting and diameter of the cutting rollers grows from the beginning to the end and in this way a narrowing channel is formed, where the tabular workpiece rotates in the opposite direction to the cutting rollers and is pushed axially, procedure characterized in that after a phase of centering entry of the section to be separated, the tabular workpiece, seeing in a longitudinal cut is completely enclosed by the contour or longitudinal of the cutting rollers without interruption of the line of contact between the workpiece and the cutting rollers, during the entire separation process and receives normal or high perpendicular forces, once axial forces on the front surface and again radial forces on the jacket surface, and front surfaces of the flat rings are generated, parallel and perpendicular to the workpiece axis, and before the separation process the tabular workpiece is subjected to a heating at an essentially lower temperature to that of resistance to the deformation of the material used, where on the outer surface a higher temperature is present than on the internal surface of the tabular workpiece.
2. - Method according to claim 1, characterized in that by supporting the introduction of the tabular workpiece in the arrangement of the cutting rollers, the arrangement is pushed with a force acting in the same direction by coupling kinematically with the rotation movement of The cutting tool is effective at least a certain length of the cutting roll.
3. Method according to claim 1 and 2, characterized in that the heating in the essential is done inductively.
4. Method according to one of claims 1 to 3, characterized in that the rings during the separation are profiled simultaneously.
5. Method according to one of claims 4, characterized in that during the separation and profiling, the tool is cooled inside and the tool as well as the workpiece to be divided receive from outside a combined cooling liquid and lubrication.
6. Device for carrying out the method according to claim 1, with three cutting rollers driven in the same direction and arranged around the tabular part to be worked with threaded blades which are seen in a longitudinal cut are provided with flanks that run essentially radial and whose width increases continuously of the entrance and exit and the base of contour between the blades of the cutting rollers is essentially parallel to the axis of rolling and each cutting rollers presents the principle finally a continuous growth of the diameter characterized in that the axes of the three cutting rollers arranged around the workpiece that is already to be divided are coupled to each other in a form-fitting in an equilateral triangle and the blades have a cutting head and a base or leg of cut with flanks directed essentially perpendicular to each axis of rolling and in the entrance part is provided a pa rte forming a funnel and the base of contour between the blades on the surface of shirt of the tabular workpiece comes to rest essentially on the same distance with respect to the axis of the workpiece and there is a heating device with temperature regulation on the inlet side and before the adjustment of the cutting rollers.
7.- Device according to the claim 6, characterized in that the flanks of the leg in a proportion of the diameter of the cutting roller to the tabular workpiece less than 3 are approximately perpendicular to the corresponding rolling axis and are inclined in a proportion equal to or greater than 3, and in a maximum of up to or less than 5o outward with respect to the radial plane of the cutting rollers.
8. Device according to claim 6, characterized in that the cutting roller has an input part.
9. Device according to claim 6, characterized in that an annular section having a sliding chamfer is pre-connected to the cutting apparatus.
10. Device according to the claim 6, characterized in that the cutting apparatus is subsequently connected to a calibration section.
11. Device according to claim 6, characterized in that in the region of entry of the cutting rollers a removable pushing device is provided, which is kinematically coupled with the rotating movement of the cutting rollers.
12.- Device according to the claim 6, characterized in that the cutting rollers consist of a central part 21, with cooling channels therein worked and a sleeve arranged around with the cutting profile and the two parts are connected to each other in a hermetic and fixed manner for rotation.
13. Device according to claim 12, characterized in that the sleeve consists of a hard material resistant to temperature. Device according to one of claims 6 to 13, characterized in that the cutting rollers for profiling the rings in the base between the blades have a negative shape of the desired profile that grows starting from 0 in step by step continuous way to its final form. SUMMARY OF THE INVENTION The invention relates to a method for the continuous and non-detachment separation of individual rings (4) equal to each other from a tabular workpiece (1) by means of cutting rollers. In order to manufacture preferably rings (4) made of steel for bearings with high accuracy it is proposed according to the present invention that the section to be separated from the tabular workpiece (1) is completely enclosed by the longitudinal contour of the rolls cutting (2) and frontal surfaces of the rings (4) flat parallel to each other and perpendicular to the axis of the workpiece. It is essential that before the separating process the tabular workpiece (1) is heated to a temperature essentially lower than the deformation resistance of the material used.