EP1521663B1 - Method and device for grinding a rotating roller using an elastic steady-rest support - Google Patents

Abstract

The invention relates to a device for grinding rollers (6), also for grinding hollow rollers. As the rollers tend to vibrate transversally as a result of the contact with the grinding disc (13), a cushioned body (15) is applied to the opposite side of the roller from the grinding disc (13), said body being engaged pneumatically against the roller (6) and adapting at least partially to the contours of the roller. The cushioned body consists of an elastic solid material or an elastic external skin that is filled with an elastic pressurised medium. The engagement pressure of the cushion is adjustable. This is achieved by a pneumatic advance cylinder (17) located on a base (16), said cylinder having a piston that can be impinged on both sides (18) and that bears on its piston rod (19) a fixing plate (20) comprising the elastic cushion (15). The advance cylinder (17) is connected to compressed air conduits (21, 22), P indicating the conduit comprising a pressure regulator and L indicating the return conduit in the standard case. The invention thus provides a device (14) for damping vibrations, which suppresses any regenerative chatter and guarantees a grinding pattern that is devoid of chatter marks.

Description

The invention relates to a method and a device according to the preamble of claim 1 or 17. Such a method and such a device is known from DE 16 27 998 A.

In many large-scale and process engineering processes, slender, elongate rolls are required which rotate during operation, are partly driven and often have to be heated or cooled from the inside. Such rolls may for example have a length of about 1000 mm and a diameter of 85 mm. The rollers are also often tubular with a small wall thickness down to 1 mm. High demands are placed on the surface quality of these rolls and on their dimensional accuracy. The grinding of such rolls to the finished size and the required surface finish therefore places high demands on the expert's skill.

A known disadvantageous aspect of external grinding of rollers is that they deflect laterally when the grinding wheel acts on its peripheral surface. This can lead to the finished roll deviating from the cylindrical shape. In addition, the roller gets into self-excited transverse vibrations, the so-called regenerative rattling. The result of this regenerative rattling are chatter marks on the peripheral surface of the roll, which mean a reduced surface quality and render the resulting roll useless for many applications.

In order to prevent bowing of rolls when grinding the outer periphery, it is known to support the roll with one or more buttocks or lunettes on its outer periphery. The pegs or lunettes are made of steel columns, which cause a support of the blank. Above all, however, the circulation of the rotating roller on the setting rods or lunettes made of steel leads to running marks, which also mean a reduced surface quality and not can be accepted. Known operational measures for the removal of regenerative rattling result in a slowing down of the grinding process.

A well-known from practice in the method of the type mentioned is that the roller is first pre-ground in Einstechverfahren with an existing corundum grinding wheel. For this purpose, the roller is processed to a roughing in the way that the grinding wheel is pierced several times side by side until the whole length of the roller is pre-ground to this degree. Subsequently, the same grinding wheel is dressed and then fine or finish ground. The finish grinding is carried out by longitudinal grinding, wherein the rotating grinding wheel and the rotating roller are moved in the longitudinal direction of the roller at its outer periphery relative to each other. With a length of the roller of, for example, 1000 mm, grinding wheels with a width of, for example, 100 mm are used for this purpose. The disadvantage of the known method is that the grinding wheels consisting of corundum often have to be dressed. This may also be required during a single finish grinding operation. Overall, the known grinding process is very tedious.

From DE 16 27 998 A1 a follower buttstock for supporting cylindrical workpieces in a grinding machine is known, which forms a hydrostatic half bearing. The rotating workpiece to be ground thus rests on a liquid film, which must be constantly renewed. For this purpose, a liquid flow is continuously fed to the hydrostatic half bearing. The liquid can be a coolant that is required anyway during grinding. With this known set the goal was pursued to effectively support the workpiece, to protect its surface and to achieve a low-friction storage, so that the setter does not have to be replaced too often. A vibration damping and the avoidance of chatter marks were not sought with the known setter and are therefore not attainable to a greater extent. Since the half bearing is made of metal, the operation of the hydrostatic half bearing must always be carefully monitored, because in the case of Collapse of the liquid film just slides metal to metal, which can damage the workpiece.

The invention is therefore an object of the invention to provide a method of the type mentioned, which allows the use of CBN grinding wheels and significantly reduced processing times, while still leading to rollers of high dimensional accuracy and surface quality.

This object is solved by the features of claim 1.

By the pad body is made in the circumferential area opposite the grinding wheel to the roller to be ground, the transverse vibrations of the roller as well as resulting from the grinding wheel vibrations are successfully damped. The regenerative rattle does not occur, and thus the dreaded chatter marks are no longer recorded. In contrast to the steel pegs or lunettes, the upholstery body does not lead to any running marks which mean reduced surface quality and can be recognized immediately by the person skilled in the art. The requirement of the circumference area opposite the grinding wheel means that the cushion body, for instance, is to be mounted radially opposite the grinding wheel on the opposite side of the roller. However, this provision is not to be understood in the strict geometric sense, because a successful fight against vibrations is also possible if the point at which the cushion body is employed against the roller, is varied radially and axially in a certain range relative to the grinding wheel. With the method according to the invention a considerable shortening of the grinding process is possible, which can be up to 50% compared to the known method. The employment of the padded body leads to plunge grinding just as successful as the longitudinal grinding.

However, it is preferred to perform the inventive method as longitudinal grinding, wherein the rotating grinding wheel 13 and the rotating roller 6 are moved in the longitudinal direction of the roller 6 at the outer periphery relative to each other. For this purpose, for example, the roller, which is mounted in tips and driven by this or by a driver for rotation, are passed on a grinding table on the rotating grinding wheel. However, the reverse arrangement is conceivable. The continuous longitudinal grinding better corresponds to an automated procedure than the piercing grinding required in paragraphs; moreover, there is no problem of the grinding marks at the crossing points.

With the method according to the invention, the disadvantageous oscillation phenomena are suppressed so successfully that a machining by means of CBN grinding wheels becomes possible. A particularly advantageous embodiment of the method according to the invention is therefore that the roller 6 in one single clamping successively with one ceramic bonded CBN grinding wheel 12, 13 is pre-ground and finished and the employment of the cushion body 6 at least during regrinding.

The following advantageous embodiments of the method according to the invention relate to how the cushion body - hereinafter collectively referred to as a "resilient pad" - hired to the roller and optionally moved towards her.

Thus, it has proved to be advantageous that the pad 15 is employed elastically yielding to the roller 6. In the simplest case, this can be done by a linear guide with a positioning spring whose tension is adjustable. Preferably, however, the employment by a pressure medium, but also an electronically controlled employment by electric motors is conceivable.

Wide application possibilities arise when the contact force with which the resilient pad 15 is made to the roller 6, is adjustable and can also be zero before the start of the grinding process. The employment of the at least one resilient pad is because the roller bends under the influence of the machining forces of the grinding wheel in the direction of the pad.

A control of the adjusting force, which can be controlled particularly well from a technical point of view, results from a pneumatic adjustment of the yielding cushion 15 to the roller 6.

The simplest method of the invention according to another embodiment is carried out in that the employment of the at least one resilient pad during grinding takes place at a constant point in the longitudinal extent of the roller. For example, if the roller is mounted between tips and the grinding wheel is guided past the outer circumference of the roller in the longitudinal direction, it is preferable to arrange the resilient pad substantially in the axial center of the roller, because there the strongest transverse vibrations occur.

An even better adapted vibration damping takes place by the at least one resilient pad 15 and the roller 6 are moved during the grinding process parallel to the longitudinal direction of the roller 6 relative to each other. If the resilient pad 15 of the grinding wheel 13 is moved radially opposite thereto relative to the roller 6, the pad is always opposite the grinding wheel and thus at the point of the vibration excitation. In this way, a particularly effective fight against vibrations can be achieved.

The developments cited below relate to the configuration of the pad and the associated supply of a lubricant and coolant in the region in which the resilient pad is placed against the roller.

Thus, for example, it is advantageous if the resilient pad 15, 23, 26, 34 adapts to the cylindrical contour when it is being set against the roller 6 to be ground. The adaptation can be carried out particularly advantageously in that a pressure medium, in particular a gas, acts on a flexible outer skin of the pad 23, 26, 34 resting against the roller to be ground 6 from the inside. In this way, the pad is inflated like a balloon that adapts softly to an obstacle.

Because of the friction occurring between the outer skin of the pad and the roller, it is advantageous if the contact point of the resilient pad 23, 26, 34 is supplied to the roller 6, a liquid or gaseous lubricant. The associated method can be particularly easily designed in such a way that the lubricant is formed by the pressure medium of the pad 34 and the contact point is supplied through outlet openings 35, which are in the roller 6 facing outer skin of the pad 34.

Further embodiments relate to how the grinding method according to the invention is controlled in detail.

Thus, a certain longitudinal contour of the roller during grinding can be achieved by setting the compliant cushion across the roller so that the roller deflects during the grinding process and by grinding in the final state a longitudinal contour of the roller with a slight concave or convex curvature comes. The roller here assumes a desired deflection during grinding, without transverse vibrations occurring. If the compliant pad has a certain distance from its outer periphery when the roller is at rest, the roller will deflect under the influence of the wheel until it touches the pad. But also the setting of a bias voltage is possible, in which case the roller is bulged in the direction of the grinding wheel. With proper control of the corresponding grinding processes arise rollers with an axial longitudinal contour, which runs in the desired manner concave or convex.

When the grinding wheel travels in the axial direction relative to the roll to be ground, the resulting transverse vibrations also change, depending on in which axial region of the roll the grinding wheel is currently located. Therefore, it is advantageous for fine tuning of the grinding process when the contact force of the at least one resilient pad is changed during the grinding process and / or is set to different values for a plurality of pads 39, 40, 41. The change in the contact force is carried out in accordance with the respective axial region of the roller, in which the grinding wheel and / or the pad just act on the roller. The required values can be quickly determined by calculations or practical experiments.

The invention also relates to a device for external grinding of rollers, in particular for carrying out the method according to the invention according to the above-cited claims. According to the invention provided according to claim 17 is thus an apparatus for grinding outer rollers 6, in particular for carrying out the method according to claims 1 to 16, with clamping and Antriebsgliedem for clamping the roller 6 at its front ends and for the rotary drive of the roller 6, with at least a grinding wheel 13 driving grinding spindle 11 which is movable in a direction transverse to the longitudinal axis of the roller 6, whereby the grinding wheel 13 against the roller 6 can be adjusted, with drives for mutual longitudinal displacement of roller 6 and grinding wheel 13 and at least one in the periphery of the roller 6 located opposite the grinding wheel 13 device 14 through which a cushion body 15, 23, 26, 34, 39, 40, 41 of a resilient solid material or an elastic, filled with an elastic pressure medium outer skin also transverse to the longitudinal direction of the roller 6 against the circumference is adjustable.

The means for adjusting the cushion body (the compliant pad) may for example be provided on the machine bed or on a grinding table which also carries the roll to be ground. The hiring can be done mechanically, electrically or by a pressure medium.

The following embodiments relate to how the contact force can be constructively advantageous and selectively applied in height. Thus, it is essential for controlling a high-quality grinding process that a control arrangement for adjusting the adjusting force is provided, with which the resilient pad 15 is employed against the circumference of the roller 6 to be ground.

If a plurality of resilient pads 39, 40, 41 arranged along the roller 6 to be ground are present, then it is advantageous that the contact force of each pad 39, 40, 41 can be adjusted individually and independently of the other pads.

Particularly good control possibilities arise when the device for adjusting the resilient pad 15 comprises a double-acting pneumatic push cylinder 17, on the piston rod 19, the pad 15 is attached. If a plurality of flexible pads 39, 40, 41 arranged along the roller 6 to be ground are present, then each pneumatic push cylinder is assigned its own pressure control valve 44, 45, 46. In this way, a perfect pneumatic control is ensured, with which the vibrations are successfully damped at several points of the axial extent of the roller.

Particular attention should be paid to the design of the upholstery. The simplest solution is that the resilient pad 15 is formed by a body of a resilient solid material. A high-quality, with closed cells trained foam plastic, which has an abrasion-resistant surface or is provided with it, can already fulfill this task well. It will already adapt to a certain extent to the outer contour of the roller and thus successfully dampen the vibrations.

Further advantages can be achieved if the resilient pad 23 is formed by a hollow body of an elastic outer skin in which a pressure medium is located. This pressure medium may be a gas, preferably compressed air. A pressurized hollow body is adapted to the outer contour of the roller particularly well suited, the effect can still be controlled by the fact that the internal pressure is optimally adjusted depending on the grinding process to be performed.

Just because such pads adapt well to the outer contour of the roller, a considerable friction between the resilient pad and the roller will occur. To reduce this, it is necessary that the lubrication and cooling agent is supplied to the contact point. For this purpose, supply lines are provided according to an advantageous embodiment, which open in the region of the contact point of the resilient pad on the roller and through which the contact point, a lubricant is supplied. Suitable lubricants are the grinding emulsions, synthetic coolants and grinding oils customary in grinding technology. But also compressed air can be considered. If the supply lines leading the lubricant are guided through the resilient pad directly to the contact point of the pad on the roller, then the lubricant is located directly where it can act most strongly. In the case of a liquid lubricant, a film forms between the roller and the compliant pad, which corresponds to the hydroplaning of the automobile tire and is particularly effective. If lubricated with compressed air, so an air cushion can be formed, as it is known from hovercraft. It must be emphasized that the lubricant film or air cushion effectively reduces the friction losses during grinding without thereby reducing the effect of vibration damping.

A structurally particularly effective solution consists in that the supply lines leading through the flexible cushion 26 are designed as hoses 30 which are made in one piece with the elastic outer skin of the pad 26, the lubricant and the pressure medium being separated from one another.

However, if the pressure medium of the pad itself as a coolant in question, it is structurally particularly simple that the elastic outer skin of the resilient pad 34 at its facing the roller to be grounded 6 contact surface with a variety is provided by outlet openings through which passes the pressure medium to form the cooling and lubricating film to the contact point. In this training must thus constantly pressure medium from the resilient pad to the contact point to pass outwards. It is a constant supply of the pressure medium required, which, however, is easy to control by pressure control valves. The solution can be perfected even further by the fact that the pneumatic control of the push cylinder, on whose piston rod the yielding cushion is located, is also included in the process.

To carry out the mentioned in the process claim 3 two-stage grinding process with hiring the resilient pad 6 to the roller at least during regrinding is constructively advantageously provided with respect to the device that a wheel spindle 8 with two grinding spindles 10, 11 is provided, which can be brought selectively into operative position and of which the first 10 carries a ceramically bonded CBN grinding wheel 12 for rough grinding and the second a ceramically bonded CBN grinding wheel 13 for finish grinding, wherein an automatic coupling is provided by which the at least one means for adjusting the resilient pad 15 to the To be ground roller 6 is activated when the second grinding spindle 11 is brought into operative position. The device according to the invention is prepared in this way for automation, which is often desired in modern mass production on production lines.

• Figur 1 zeigt eine Vorrichtung durch Durchführung des erfindungsgemäßen Verfahrens, wobei die Phase des Vorschleifens dargestellt ist.
• Figur 2 stellt die Vorrichtung gemäß Figur 1 in der Phase des Fertigschleifens dar.
• Figur 3 ist eine vergrößerte Ansicht entsprechend der Blickrichtung A-A gemäß Figur 2 und zeigt Einzelheiten des nachgiebigen Polsters im Zusammenwirken mit der zu schleifenden Walze.
• Figur 4 hat eine andere Ausführung des nachgiebigen Polsters zum Gegenstand.
• Figur 5 zeigt die Zufuhr eines Schmiermittels im Bereich des nachgiebigen Polsters.
• Figur 6 veranschaulicht ein nachgiebiges Polster, dessen Druckmedium zugleich als Schmiermittel dient.
• Figur 7 enthält ein Schema, das die Steuerung mehrerer Einrichtungen zum Anstellen elastischer Polster an unterschiedlichen axial beabstandeten Stellen der Walze verdeutlicht.

The invention will be explained in more detail with reference to embodiments which are illustrated in the figures. In the figures, the following is shown:

• FIG. 1 shows a device by carrying out the method according to the invention, wherein the pre-grinding phase is shown.
• FIG. 2 shows the device according to FIG. 1 in the phase of finish grinding.
• Figure 3 is an enlarged view corresponding to the viewing direction AA of Figure 2 and showing details of the resilient pad in cooperation with the roller to be ground.
• Figure 4 has another embodiment of the resilient pad for the subject.
• Figure 5 shows the supply of a lubricant in the region of the resilient pad.
• Figure 6 illustrates a resilient pad, the pressure medium also serves as a lubricant.
• Figure 7 contains a diagram illustrating the control of a plurality of means for adjusting elastic pads at different axially spaced locations of the roller.

FIG. 1 is a schematic representation of a conventional cylindrical grinding machine for external grinding of cylindrical parts. In a view from above, a machine bed 1 can be seen, on which a workpiece headstock 2 and a tailstock 3 are located. Workpiece headstock 2 and tailstock 3 are mutually adjustable in the axial direction, so that by means of the tips 4 and 5 located on them, the roller 6 to be ground can be clamped and driven for rotation. However, the roller can also be driven by drivers, which are customary and therefore not shown separately here. The workpiece headstock 2 and the tailstock 3 are located on a grinding table 7, which can be moved as a whole in the Z direction.

On the machine bed 1 is still a wheel spindle 8, which is adjustable about a vertical pivot axis 9. The grinding headstock carries a first grinding spindle 10 and a second grinding spindle 11. Of these, the first grinding spindle 10 carries a first grinding wheel 12, which serves for roughing or roughing, while the second grinding spindle 11 carries a second grinding wheel 13 intended for finish grinding or finishing.

By pivoting about the vertical pivot axis 9, the wheelhead 8 moves in the direction of arrow B, so that either the grinding wheel 12 (Figure 1) or the second grinding wheel 13 (Figure 2) can be brought into operative position. In addition, the entire wheelhead 8 can be moved numerically controlled in the X direction, whereby the grinding wheel, which is in the active position in each case, comes into contact with the roller 6 to be grounded in a controlled manner.

As can be seen, the axial length of the roller 6 to be ground is a multiple of the grinding wheel width, so that for grinding during so-called longitudinal grinding, the grinding wheel and the roller to be grounded must be moved past each other in the axial direction. For this purpose, the roller 6 located on the grinding carriage can be moved past the grinding wheel. However, it is also the reverse arrangement possible that the roller to be ground is fixed in the axial direction, while the wheel head is moved past her.

With a vibration damping device 14 is designated, by means of which a resilient pad 15 can be controlled to the roller employed. Figure 1 shows the device 14 in its ineffective position; In this case, the resilient pad 14 is at a distance from the surface of the roller to be ground. On the other hand, in the illustration according to FIG. 2, the yielding cushion 15 is set against the roller. It is located in the radial direction opposite the grinding wheel 13. When the grinding wheel acts on the roller 6, this will bend laterally and thereby tend to transverse vibrations, especially when the length / diameter ratio is greater than shown in the drawing. Also, tubular rolls with low material thickness are particularly susceptible to such vibrations. By now placing the compliant cushion 15 against the roller at a moderate, adjustable pressure, the transverse vibrations are damped and suppressed, so that the "regenerative rattle" feared by those skilled in the art does not occur. This also eliminates the bad surface quality of the ground roller betraying chatter marks.

Although in the illustration according to Figures 1 and 2, the device 14 is exactly opposite the grinding wheels 12 and 13. However, when the roller 6 to be ground by means of the grinding table 7 in the axial direction of the grinding wheel is moved past, also changes the position of the Device 14 in relation to the grinding wheel. It is therefore advantageous if, over the axial extension of the roller 6 to be ground, a plurality of devices with various resilient cushions are provided, as illustrated in FIG. 7, which will be explained in more detail later.

However, it is also conceivable to arrange the device 14 on the machine bed so that it always remains exactly opposite the grinding wheel in operative position. Finally, a solution is conceivable in which, although only one device 14 is provided, but this is moved axially together with the grinding spindle relative to the roller to be ground, so that the mutual association of grinding wheel and device 14 is maintained in any case.

Figures 1 and 2 illustrate at the same time a particularly preferred method according to the invention, in which the pre-grinding is carried out by means of a ceramic bonded CBN grinding wheel while the device 14 for damping the vibrations still remains out of operation. However, if the grinding wheel 13 is brought into operative position for finish grinding, the device 14 is automatically coupled with it, as is shown in FIG. In finish grinding or finishing transverse vibrations are thus effectively suppressed, so that optimum surface qualities are achieved despite a short processing time.

3 shows the view AA according to Figure 2 in an enlarged view. It explains a device for vibration damping, which is pneumatically operated. For this purpose, a base 16 is provided, which may be attached directly to the machine bed 1 or to the grinding table 7. The base 16 carries a pneumatic double-acting thrust cylinder 17, in which a piston 18 can be acted upon from two sides. The piston 18 carries a piston rod 19, to which a mounting plate 20 is located. On the mounting plate 20 is the yielding Pad 15 glued or vulcanized. The pad may be made of a rubber-like material or a plastic with closed hollow cells, which is thus particularly flexible and adaptable. It is crucial that the outer surface of the resilient pad 15, although elastic, but yet resistant and resistant to abrasion. 21 and 22 are compressed air lines through which the thrust cylinder is controlled. He can thus press the resilient pad 15 with precisely adjustable contact force against the roller 6. As can be seen, the roller 6, which in this case is a hollow roller, is acted on both sides between the grinding wheel 13 and the resilient pad 15. The roller will thus dodge slightly under the contact force of the grinding wheel 13, but occurring transverse vibrations are suppressed by the damping effect of the resilient pad 15.

The basic position of it yielding pad 15 before the start of the grinding process is adjustable. For example, at the beginning of the contact force zero, so that only under the action of the grinding wheel 13, a depression of the roller 6 takes place in the resilient pad 15.

In Figure 4, a device 14 for vibration damping is shown, in which the resilient pad 23 is formed as a hollow body with an elastic outer skin, comparable to the pneumatic tire of vehicles. For example, compressed air may be introduced into the interior of the resilient pad 23 with a supply conduit 24, whereby different elasticity characteristics may be achieved. But it is also conceivable to fill the resilient pad with a liquid, if an elastic retraction of the liquid is ensured. Also, filling with a gel comes into consideration.

The rest of the construction of the device 14 corresponds to that of Figure 4, in particular, the hiring of the resilient pad 23 must be made to the roller 6 with a special device such as a push cylinder here.

FIG. 5 also explains a compliant pad 26 filled with a pressure medium, which is also located on a mounting plate 25 and connected thereto. The mounting plate 25 is connected to a supply line 27 for the pressure medium, for the compressed air comes into question in the first place. Via an internal, located in the mounting plate 25 channel 28, the pressure medium is introduced into the cavity of the resilient pad 26. By the resilient pad 26 tubes 30 are passed, which consist of the outer skin of the pad 26 in one piece, but have no connection to the interior of the pad 26. The hoses 30 are connected to a channel system 29, which is located in the mounting plate 25 and by a cooling and lubricating medium by means of the hoses 30 is applied directly to the contact surface of the resilient pad 26 on the roller 6. For this purpose, the hoses 30 end in outlet openings 31, which are directed directly to the roller 6. As can be seen, the outlet openings 31 open on the surface of the roller 6, so that the coolant and lubricant reaches exactly where it is most needed.

Designated with P11 and P12 pressure regulators, which are used to set the optimum operating pressure of the media.

If the pressure medium located in the hollow compliant padding can simultaneously serve as coolant and lubricant, separate supply lines for the pressure medium of the pad on the one hand and the cooling and lubricating medium on the other hand are no longer required. The constructive implementation which is advantageous in this case is shown in FIG. 6.

Thereafter, a compliant pad 34 is glued or vulcanized onto a mounting plate 32 again, wherein a supply line 33 via a pressure regulator P21 leads into the interior of the resilient pad 34. In this case, the resilient pad is provided at its the roller 6 facing end side with a number of outlet openings 35. Thus, the pressure medium of the pad passes continuously through the outlet openings 35 in the direction of the surface of the roller 6. In this case, the resilient pad 34 must be continuously updated pressure medium so that the required contact pressure is maintained.

FIGS. 4 to 6 show how well the inflatable pads conform to the contour of the roller. In the case of Figures 5 and 6 is achieved in a particularly secure manner that the cooling and lubricating medium between the resilient pad and the roller forms a film, comparable to the water film in the so-called aquaplaning or air cushion in vehicles of the type Hoovercraft vehicles. The embodiment according to FIG. 6 is particularly advantageous when working with an air cushion.

FIG. 7 shows diagrammatically how the actuation of the devices for vibration damping is to take place when several of these devices are provided along the axial extent of the roller 6 to be ground. In the case shown, three means 36, 37, 38 are provided, each of which a resilient pad 39, 40, 41 hires to be ground roller 6. The hiring takes place pneumatically, to which each of the devices 36, 37, 38 may have a push cylinder according to the figure 3. As can be seen, the oscillation amplitudes in the middle of the roller 6 clamped between the tips 4 and 5 will be greater than in the region of their outer ends, which are closer to the clamping points. Therefore, it is expedient to choose the adjusting force of the device 37 higher than that of the devices 36 and 38. Accordingly, in the compressed air supply line P for each of the devices 36, 37, 38, a separate pressure control valve 44, 45, 46 is provided, so that the thrust cylinder of each device can obtain the optimum for the vibration damping pneumatic pressure. Moreover, the compressed air supply lines P and return line L are formed together for all facilities.

References list

1

machine bed

2

Workhead

3

tailstock

4

top

5

top

6

roller

7

grinding table

8th

Wheelhead

9

swivel axis

10

first grinding spindle

11

second grinding spindle

12

first grinding wheel

13

second grinding wheel

14

Device for vibration damping

15

soft upholstery

16

base

17

push cylinder

18

piston

19

piston rod

20

mounting plate

21

Compressed air line

22

Compressed air line

23

soft upholstery

24

supply line

25

mounting plate

26

soft upholstery

27

supply line

28

internal channel

29

channel system

30

tube

31

outlet openings

32

mounting plate

33

supply line

34

soft upholstery

35

outlet openings

36, 37, 38,

Device for vibration damping

39, 40, 41

soft upholstery

42, 43

control line

44,45,46

Pressure control valve

Claims (28)

1. A method for peripheral grinding the exterior of a rotating roller (6) supported at its ends, by means of a rotating grinding wheel (13), with the length of said roller (6) being a multiple of the width of said grinding wheel, characterized in that during grinding, at least one padding body (15, 23, 26, 34, 39, 40, 41) made of a solid elastic material, or an elastic outer skin filled with an elastic pressure medium, is brought into contact with the roller (6) to be ground in the peripheral area opposite said grinding wheel (13).
2. The method of claim 1 characterized in that it is performed as a longitudinal grinding operation, in which said rotating grinding wheel (13) and said rotating roller (6) are moved relative to each other on the outer periphery of said roller (6) in a longitudinal direction of the latter.
3. The method of claim 2 characterized in that said roller (6) is successively rough-ground and finish-ground in a single clamping, each time using a ceramically bonded CBN grinding wheel (12, 13), and that said padding body (6) is brought into contact with the roller at least for regrinding.
4. The method of one of the preceding claims characterized in that said padding body (15) is brought into contact with said roller (6) in an elastically flexible manner.
5. The method of one of the preceding claims characterized in that the force with which said padding body (15) is brought into contact with said roller (6) is adjustable and may also be at zero before the beginning of the grinding operation.
6. The method of one of the preceding claims characterized in that said padding body (15) is brought into contact with said roller (6) pneumatically.
7. The method of one of the preceding claims characterized in that said at least one padding body will be brought into contact with said roller at a constant position in the longitudinal extension of said roller during grinding.
8. The method of one of the preceding claims characterized in that during the grinding operation, said at least one padding body (15) and said roller (6) will be moved relative to each other and in parallel to the longitudinal direction of said roller (6).
9. The method of claim 8 characterized in that in doing so, said padding body (15), in a radial position substantially opposite said grinding wheel (13), will be moved relative to said roller (6) together with said grinding wheel (13).
10. The method of one of the preceding claims characterized in that when said flexible padding body (15, 23, 26, 34) is brought into contact with the roller (6) to be ground, the former will adapt to the cylindrical contour of said roller (6).
11. The method of claim 10 characterized in that such an adaptation will be obtained by a pressure medium, in particular a gas, acting from the inside on an elastic outer skin of said padding body (23, 26, 34) which lies against said roller (6) to be ground.
12. The method of one of the preceding claims characterized in that a liquid or gaseous lubricant will be supplied to the place where said flexible padding body (26, 34) contacts said roller (6).
13. The method of claim 12 which refers back to claim 11 characterized in that said lubricant is formed by the pressure medium of said padding body (34) and will be supplied to the contact site via exit apertures (35) provided in the outer skin of said padding body (34) facing said roller (6).
14. The method of one of the preceding claims characterized in that said padding body will be set transversely to said roller so as to cause said roller to bend out during grinding, and that grinding in the final state will produce a longitudinal contour of said roller which exhibits a slightly concave or convex curvature.
15. The method of one of the preceding claims characterized in that the force with which said at least one padding body is brought into contact with said roller will be varied during grinding and/or will be set at a different value for each of a plurality of padding bodies (39, 40, 41).
16. The method of claim 15 characterized in that the force with which the padding body is brought into contact with said roller will be varied according to the respective axial area of said roller where either said grinding wheel and/or said padding body will act on said roller.
17. A device for externally grinding rollers (6), in particular for performing the method of claims 1 to 16, with clamping and driving elements for clamping said roller (6) at its frontal ends, and for rotationally driving said roller (6), including at least one grinding spindle (11) driving at least one grinding wheel (13), said spindle (11) being capable of travelling in a direction transverse to the longitudinal axis of said roller (6) so as to bring said grinding wheel (13) into contact with said roller (6), including drives for the mutual longitudinal displacement of said roller (6) and said grinding wheel (13), and including at least one means (14) located in the peripheral area of said roller (6) opposite said grinding wheel (13) characterized in that said means (14) enables a padding body (15, 23, 26, 34, 39, 40, 41) of a solid elastic material, or an elastic outer skin filled with an elastic pressure medium, to be brought into contact with the periphery of said roller (6) likewise transversely to a longitudinal direction thereof.
18. The device of claim 17 characterized by control means for adjusting the force with which said padding body (15) is brought into contact with the periphery of said roller (6) to be ground.
19. The device of claim 18 including several flexible padding bodies (39, 40, 41) arranged along said roller (6) to be ground characterized in that the force with which each padding body (39, 40, 41) is brought into contact with said roller can be adjusted individually and independent of the other padding bodies.
20. The device of claim 18 or 19 characterized in that the means for bringing said flexible padding body (15) into contact with said roller comprises a double-action pneumatic pushing actuator (17) which has said padding body (15) mounted on its connecting rod (19).
21. The device of claim 20 including several padding bodies (39, 40, 41) arranged along said roller (6) to be ground characterized in that a respective pressure control valve (44, 45, 46) is provided for each pneumatic pushing actuator.
22. The device of one of claims 17 to 21 characterized in that said elastic pressure medium is pressurized air.
23. The device of one of claims 17 to 22 characterized in that supply lines are provided which terminate at the roller in the area of the contact point of said padding body and through which a lubricant is supplied to said contact point.
24. The device of claim 23 characterized in that grinding emulsions, synthetic cooling lubricants, grinding oils or a gas, in particular pressurized air, are intended for use as lubricants.
25. The device of claims 23 or 24 characterized in that the supply lines for supplying said lubricant extend through said padding body directly to the contact point of said padding body on the roller.
26. The device of claim 25 including a padding body (26) consisting of an elastic outer skin filled with an elastic pressure medium characterized in that the supply lines which extend through said padding body (26) and supply said lubricant are in the form of tubes (30) which are integrally formed with the elastic outer skin of said padding body (26), with said lubricant and said pressure medium being separated from each other.
27. The device of claim 26 characterized in that the elastic outer skin of the elastic padding body (34) has a plurality of exit apertures in its contact surface facing said roller (6) to be ground, through which said pressure medium passes on to said contact point in order to form a cooling and lubricating film thereon.
28. The device of one of claims 17 to 27 characterized in that a grinding spindle stock (8) including two grinding spindles (10, 11) is provided which can be selectively moved into their active positions, with the first (10) of said spindles carrying a ceramically bonded CBN grinding wheel (12) for rough grinding and the second of said spindles carrying a ceramically bonded grinding wheel (13) for finish grinding, and that an automatic coupling is provided which is used for activating said at least one means for bringing said elastic padding body (15) into contact with said roller (6) to be ground when said second grinding spindle (11) is moved into its active position.

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