EP1066125A1

EP1066125A1 - Roller

Info

Publication number: EP1066125A1
Application number: EP98965844A
Authority: EP
Inventors: Karl-Heinz Küsters
Original assignee: Kuesters Beloit GmbH and Co KG
Current assignee: Eduard Kuesters Maschinenfabrik GmbH and Co KG
Priority date: 1998-01-24
Filing date: 1998-12-16
Publication date: 2001-01-10
Also published as: WO1999037416A1; CA2319244A1; DE19802723A1

Abstract

The invention relates to a flexion-controllable roller (100), comprising a plurality of inner support elements (10) that can be individually controlled by valves. The valves comprise actuators (80) with a shaped body (90) that changes its expansion in at least one dimension when an electrical current is applied. Said change serves to control the valves (50).

Description

W a l z e

The invention relates to a roller of the type corresponding to the preamble of claim 1.

A "roller" in the present sense is to be understood as the actual roller together with the associated control and regulating device.

An older embodiment of such a roller is the subject of DE 25 22 657 B2. In the older publications on such roller arrangements there are always relatively few, i.e. In the order of magnitude, around ten support punches are lined up in a deflection-controllable roll along the roll gap. These relatively few supporting stamps were partly combined in small groups that were controlled together, for example groups that were arranged left-center-right, seen in the transverse direction of the web of goods, or, as in DE 25

22 657 B2 in four groups of two support elements each. In the latter case, it was only necessary to have four hydraulic fluid quantities available under individual pressures. However, this alone caused a not inconsiderable effort, as shown in FIG. 7 of DE 25 22 657 B2, whereby it should be noted that the valves and their controls are only shown schematically and the actual design represents an even greater effort. To the extent that roller assemblies of the type in question left the phase of fundamental considerations behind and were put into practice, it became apparent that the number of supporting elements, if the advantages of this type of internal support of hollow rollers were to come into play , had to be enlarged compared to the schematic representations of the first applications from the 1970s. In the newer DE-GM 93 14 568 up to fifty support elements are provided in close succession in a line along the roll gap, all of which should be individually controllable, so that in combination with the use of a particularly flexible roller tube, an optimally sensitive adjustment of the line force profile is ensured to the train becomes possible. With such a roller arrangement, not only three or four, but with a roller length of 6 to 7 m and a length of the approximately 100 mm wide, closely adjacent support elements of approximately 100 mm, for example, 56 quantities of hydraulic fluid under individual pressures are to be provided.

The electrohydraulic pressure systems that have become known for supplying the individual support elements work with the usual actuators for the valves, that is to say either with strong electromagnets with correspondingly expensive electrical amplifiers or with small ones

Magnets and corresponding hydraulic reinforcement, whose susceptibility to dirt is high. Hysteresis phenomena in the pressure control behavior represent a particular problem here. It is readily apparent that the arrangement and control of such printing systems more than fifty times means an effort which may well exceed that for the actual roller.

The invention has for its object a pressure supply system for a generic roller assembly to create, which meets the requirements for accuracy and reliability with less effort. This object is achieved by the invention reproduced in claim 1. The actuator which brings about the displacement of the valve member which determines the pressure and / or the amount of pressure medium for the individual support element is essentially only a shaped body which, when an electrical voltage is applied, increases or decreases or lengthens as a function of this or shortened, at least in one dimension its extent changed. The forces required to actuate the valve member can be applied by relatively small shaped bodies which do not require any significant additional space beyond that of the valve itself. There is no need to implement forms of energy (electrical / hydraulic or pneumatic / hydraulic) which were sources of inaccuracies and unreliability in the previously known actuators. The actuators only require electrical lines to supply the actuating energy, which only require a minimum of cross-section and are easy to bend as required. Different pipe lengths do not have as much influence as is the case with hydraulic pipes.

In the preferred embodiment of the invention, the fluid pressure medium is a pressure fluid, but can also be a gas, in particular air.

A number of such actuators are known in the art. The achievable strokes of such actuators are not too great. The design of the valves may need to be adjusted accordingly in individual cases. However, the invention does not consist in the actuators as such, but rather in the use of one actuator each on one valve for providing the pressure fluid for an individual support element in a deflection-controllable roller.

The shaped body of the actuator should consist of a single, contiguous piece, in contrast to an electromagnet, which has always been known as an actuator for valves, but consists of separate, mutually movable parts, namely the coil and the armature.

The above-described actuator of a valve for supplying a support element in a roller arrangement of the type described can act directly on the valve member, this being a question of dimensioning the shaped body. In the case of direct actuation, the molded body must be able to apply the required actuating forces (claim 2).

But it is also possible to use such an actuator for pilot control of a valve (claim 3).

In the preferred embodiment of the invention, the valve member is a valve spindle which can be displaced in the direction of its axis (claim 4) and which can be piloted in particular in the manner set out in claim 5.

A first type of actuator in question is one in which the shaped body changes its shape due to an electrochemical effect.

Such actuators are described in EP 670 962 Bl and EP 670 963 Bl.

This type of actuator particularly suits the intended use in terms of its timing behavior. With the deflection-controllable rollers, high positioning speeds are not required for the adjustment of the pressures in the individual support punches. The usual response times are in the order of 10 to 20 seconds. This is precisely the order of magnitude that actuators also show, their effect on an electrochemical

Effect based. Another type of actuator that can be considered are those based on a piezoelectric effect (claim 7).

Such actuators are described in the article by Tönshoff and Laux "Piezo Actuators for the mm Range" in VDI-Z Special Drive Technology, April '94, pages 48 to 52. A specific application of a piezoelectric element as an actuator for an application valve for glue can be found in DE 43 25 143 Cl. Another type of actuator in question is one in which the shaped body changes its shape due to a magnetostrictive effect (claim 8). This has already been described for the control of nozzle needles in injection valves in DE-PS 695 974. The forms discussed above show the common feature that the application of voltage to the molded body immediately causes the shape change. Another group of actuators in question is characterized by an indirect effect of the change in shape, in that it is caused by a temperature change generated thermoelectrically by the applied voltage.

This includes that the shaped body is thermally expanded due to its coefficient of expansion due to the thermoelectric temperature change.

So that a sufficiently large displacement occurs in this way, it can be recommended that the molded body contains a so-called expansion material, which therefore has a particularly large coefficient of expansion. This also includes an element with a temperature-dependent shape change memory, which exhibits behavior as described in US Pat. No. 5,197,720.

1 shows a schematic view of a rolling device with a roller according to the invention; Fig. 2 shows a partial cross section through the roller in a plane perpendicular to the axis through a single support element;

3 shows a longitudinal section through a valve serving to supply such a support element with the associated actuator.

The roller designated 100 as a whole in FIG. 1 comprises an non-rotatable crosshead 1, which extends through a circumferential hollow roller 2 lengthwise with all-round spacing. The ends 1 'of the crosshead 1 protruding from the hollow roll 2 are mounted in a manner not shown in a roll stand or the rocker arms of a calender or in a similar manner.

In the embodiment shown in FIG. 1 at the right end of the hollow roller 2, the hollow roller 2 is mounted on the crosshead 1 via a roller bearing 3. At the left end of the hollow roller 2, an embodiment variant is shown in which the hollow roller 2 is supported by a bearing 4 on a ring 5, which can shift somewhat from top to bottom relative to the crosshead 1, but cannot rotate. A straight guide in the form of two mutually opposite flats 6 of the crosshead 1 is provided on the crosshead 1, on which the guide ring 5 can slide parallel to the plane of the drawing with corresponding guide surfaces (not shown). The camp 3 can

To transmit forces in the direction of action of the roller 100 from the hollow roller 2 to the crosshead 1, the bearing 4 has only management tasks perpendicular to the effective plane, which is to be regarded as the connecting plane of the axis of the hollow roller 2 and the counter roller 15. In the effective plane, because of the displaceability of the guide ring 5, no forces can be passed on from the hollow roller 2 to the crosshead 1. It is understood that in a practical roller, the formation at the two ends of the hollow roller 2 is the same. The illustration in FIG. 1 serves only to explain the

Types of rollers for which the invention can be considered. Numerous support elements 10 are arranged in the roller 100 over the length of the hollow roller 2 in close succession along the roller 100 on the side of the roll gap 14, which are supported on the crosshead 1 and rest with their support surface 7 against the inner circumference 8 of the hollow roller 2. In the exemplary embodiment shown, the length of the hollow roller 2 is approximately 6.50 m and 56 support elements of approximately 100 mm axial extent are provided axially close to one another, only four of which are shown at the ends. The support elements 10 are supplied via a common feed line 9 and branch lines 11 leading to the individual support elements 10 and additionally via separate feed lines 12 assigned to each individual support element 10, which separate the hydrostatic bearing of the support elements 10

Take over the inner circumference 8 of the hollow roller 2 or press the support elements 10 against the inner circumference 8 of the hollow roller 2, as will be explained in detail in connection with FIG. 2. The fifty-six hydraulic fluid quantities in the feed lines 12 determine the line force profile in the roll gap 14.

In the embodiment shown in Fig. 1, the roll gap 14 is located at the top, i.e. a counter roller 15 abuts the web B made of paper, cardboard, plastic, textile, fleece, sheet metal or the like against the working outer circumference of the roller 2. This results in a line load for the hollow roller 2, which is intercepted by the support elements 10 and forwarded to the crosshead 1, which bends downwards under this line load according to FIG. 1, which is due to the all-round distance (which in FIG 1 is shown exaggerated) is possible, whereby the hollow roller 2 can be kept free from strain-related changes in shape. As indicated in Fig. 2, there is the hollow roller

2 made of plastic, in particular a fiber-reinforced 8th

Synthetic resin, whereby the radial wall thickness 13 does not exceed 20 mm. The hollow roller 2 is thereby particularly flexible compared to a steel roller and can transmit the profile of the forces exerted by the support elements 10 to the web B in a largely similar manner. The interaction of the flexible hollow roll 2 with the numerous support elements results in a particularly sensitive controllability of the line force profile along the roll gap 14.

1 shows the pair of rolls 100, 15, in the roll nip 14 of which the web B is pressure-treated. Above the counter roller 15, another part of the web B following the nip 14 in the running direction of the web B is indicated in a reduced manner, on which a property profile such as moisture distribution, density distribution, thickness distribution transverse to the web is measured by means of measuring devices 21, nine of which are shown in the exemplary embodiment is measured. The measured values of the individual measuring devices 21 are fed to a control and regulating device 30 via lines 22. Instead of the nine measuring devices 21, a single, traversing measuring device could also be used.

The control and regulating device 30 is supplied with pressure fluid by a pump 23 via a line 26 and separately allocates pressure fluid to the individual supporting elements 10 via the lines 12, which pressures are formed from the measured values of the measuring devices 21 by an algorithm stored in the control device 30 become.

The algorithm includes the mechanical properties of the rolling device, i.e. he indicates in which

How the line force distribution in the roll gap 14 changes when the force exerted changes in a certain support element 10 by a certain amount. The control and regulating device 30 comprises a computer 40 which specifies what pressures in the many supply lines 12 are so that, for example, a constant moisture profile in web B is established across the width of web B.

A second pump 24 sends pressure fluid via a pressure regulator 25 into line 9, which supplies all support elements 10 via branch lines 11 with a second regulated pressure that is the same for all support elements. This pressure fluid can be tempered in order to bring about a corresponding tempering of the hollow roller 2.

Below the roller 100, for example, a line force distribution L _κ over the web width W _{B is} indicated, as it results from the values measured by the measuring devices 21 after the calculation of the control device 30. L _κ are the forces that the individual support elements exert. The hollow roller 2 is still a rigid tube, in comparison with a steel tube of the wall thickness customary in deflection-controllable rollers but with bending stresses in a plane passing through the axis, so that the line force profile indicated in the lower part of FIG. 1 is due to the in Fig. 2 indicated mechanism "breaks through", ie largely true to the web B, although somewhat weakened, can be realized.

FIG. 2 shows an individual support element 10, which rests with its support surface 7 against the inner circumference 8 of the hollow roller 2. The support element 10 comprises a piston / cylinder unit with an annular piston 31, which is attached to the flattened upper side 1 "of the crosshead 1 facing the roll gap 14. The cup-shaped" cylinder "32, which lifts in relation to the annular piston 31, is placed over the annular piston 31. and can be lowered and is sealed on its inner circumference with respect to the ring piston 31 by means of seals 33. The bottom 34 of the "cylinder" 32 has a tubular, central extension 35 pointing towards the open side, which engages in the ring opening of the ring piston 31 and there by means of Seals 36 is sealed, the annular piston 31 has an axially parallel 10

Bore 37, which opens into the supply line 12 leading to the relevant support element 10. The branch line 11 leads into the interior of the annular piston 31.

The outside of the bottom 34 facing the inner circumference 8 of the hollow roller 2 is covered by a cap-shaped plastic part 39, which consists of a shape-retaining but somewhat flexible material that forms a sliding pairing with the coating 20. On the inner circumference 8 of the hollow roller 2 facing the cap 39 is partially cylindrical, so that it

Inner circumference 8 fits snugly. The cap 39 there forms the support surface 7, in which one or more flat bearing pockets 42 bordered all around are recessed, which can be provided with pressure fluid from the inside of the tubular extension 35 via throttle bores 41. The hydraulic fluid entering the interior of the tubular extension 35 from the branch line 11 thus reaches the bearing pockets 42 via the throttle bores 41 and exerts a hydrostatic pressure there against the inner circumference 8 of the hollow roller 2. The pressure fluid flows continuously over the edges of the bearing pockets 42 and forms a load-bearing liquid film on these edges in the support surface 7, via which the force of the support element 10 is transmitted to the inner circumference 8 of the hollow roller 2. The pressure in the branch lines 11 is about

Pressure regulator 25 regulated, namely to a value that is the same for all support elements 10. The storage pockets 42 of all support elements 10 are supplied via the single line 9, which is common to all support elements. The force of the support element 10 is determined by the pressure of the cylinder chamber 38 formed between the bottom 34 of the "cylinder" 32 and the top of the "piston" 31. The pressure fluid required for this is supplied separately to each support element 10 via its own feed line 12. Since the "cylinder" 32 shifts only a little radially during normal operation, the 11 loading of the cylinder chamber 38 required amounts of liquid also very low. The leads 12 can therefore have a very small diameter, so that the necessary cross-sectional portion inside the hollow roller 2, be it inside the crosshead 1 or on the outside thereof, even with larger numbers of support elements 10 without significant weakening of the crosshead 1 can be made available.

The design of the cap 39 made of plastic should result in a certain resilience of the support surface 7, in order to avoid excessive surface pressures at the transition points in the case of strong pressure differences in the case of successive support elements in the axial direction, as can occur according to the diagram in the lower part of FIG. 1 to let come.

The support elements 10 have a rectangular cross section in the plan view according to FIG. 1 from above and follow one another in the longitudinal direction of the hollow roller 2 directly or with only small distances. The distances must be such that adjacent support elements 10 do not come into contact with one another when the crosshead 1 or the hollow roller 2 bends and hinder each other in their lifting movement. The axial extent of the individual support element 10 should not exceed 20 cm in order to achieve the finest possible support of the hollow roller 2.

The control and regulating device 30 for supplying hydraulic fluid quantities under a large number - in the exemplary embodiment 56 - of different pressures would be very complex with conventional means and not particularly reliable. For this reason, the individual valves 50, of which only eight are indicated schematically in FIG. 1 and each of which is assigned to a specific support element 10, have actuators 80 of a special type which are controlled by the computer 40 via lines 83. The actuators 80 require little space and 12 allow entire valve groups to be combined in banks or blocks, as is also otherwise customary in hydraulic technology.

The actuators 80, which are only indicated by crossed small rectangles in FIG. 1, have the feature that they comprise a shaped body which changes its shape in at least one dimension when an electrical voltage is applied, be it by an electrochemical reaction, by the piezoelectric or by the magnetostrictive effect or otherwise.

3 shows an exemplary embodiment in which the valve 50 is accommodated in a block 45 and the actuator 80 is seated on the surface of the block 45. At the location of each valve 50, a blind bore 43 is provided in the block 45, which widens towards the block surface in one step to a threaded bore 44. In the blind bore 43 there is a valve sleeve 51 which, in the region of the blind bore 43, carries four O-rings 52, 53, 54, 55, which are successive in the axial direction and seal the three sections 56, 57, 58 against one another and to the outside in the region of the blind bore 43. The line 26 of the pump 23 opens at the level of the section 56. The valve sleeve 51 here has a radial through bore 27, so that hydraulic fluid can pass from the line 26 into the slide bore 46 of the valve sleeve 51. In the region 57, the line 12 opens to the support element 10 assigned to the valve 50 shown. Pressure fluid can get into the line 12 from the slide bore 46 through radial through bores 28 of the valve sleeve 51 provided in the section 57. In section 58, the valve sleeve 51 has radial through bores 29 which connect the slide bore 46 to a return line 47 to the tank.

In the slide bore 46 of the valve sleeve 51 is a valve member in the form of a valve slide

Valve spindle 60 axially displaceable, the three in axial direction 13 device spaced from each other, sealingly in the slide bore 46 abuts webs 61,62,63, which are interconnected by sections 64,65 of reduced diameter. Section 64 is at the height of section 56, section 62 is at the height of section 57 and section 65 is at the height of section 58.

The valve spindle 60 has a central longitudinal bore 66, which is delimited at the ends by throttles 67, 68 and has a transverse bore 69 in the region of the section 57. At the upper edge of the web 62, in which the transverse bore 69 extends, through which hydraulic fluid can pass into the longitudinal bore 66, the control cartridge 70 is formed, which is decisive for the allocation of the hydraulic fluid into the line 12. The upper end 59 of the valve sleeve 51 engages in the threaded shoulder 71 of the actuator 80, with which the latter is screwed into the threaded bore 44. Between the end of the valve spindle 60 there and the bottom 72 of the bore receiving the upper end 59 of the valve sleeve, a helical compression spring 73 is provided which continuously presses the valve spindle 60 downward.

The threaded shoulder 71 of the actuator 80 has a central through bore 74, which leads to a valve seat 75, and a lateral through bore 76, which leads to a return line 77 into the tank.

The actuator 80 comprises a pot-shaped housing 81, on the bottom of which the threaded shoulder 71 is formed, and a cover 82 through which the electrical leads 83 are led. Inside the pot-shaped housing 81 is an in

Metal bellows 84, which is expandable in the direction of the axis A, is attached to the cover 82 with its upper end and carries an outwardly projecting nozzle needle 85 at its closed lower end, which cooperates with the valve seat 75. 14

Provided in the metal bellows 84 is a shaped body 90, indicated by broken lines, which increases its volume with a certain actuating time when an electrical voltage is applied via the supply lines 83. As a result, the pressure inside the gas-filled bellows 84, which is closed on all sides, increases, and the force on the nozzle needle 85 correspondingly increases.

In operation, a pressure builds up on the line 26 from the pump 23, which reaches the central longitudinal bore 66 via the transverse bore 69 of the valve spindle 60 when the valve spindle 60 is initially in the lower position under the force of the spring 73 and because of the Throttles 67, 68 with a slight delay are also present in the end chambers 87, 88 in front of the end faces of the valve spindle 60. However, the pressure in the upper end chamber also prevails in the central bore 74 and tends to lift the nozzle needle 85 off the valve seat 75. This tendency is counteracted by the force of the prestressed gas located in the metal bellows 84. If this force remains constant, an equilibrium is established in which a lower pressure prevails in the upper end chamber 87 than in the lower end chamber 88. The latter corresponds to the pressure under the nozzle needle corresponding to the force of the metal bellows 84. Under this pressure difference, the valve spindle 60 seeks against the force of the

Spring 73 to shift up and will find a certain equilibrium position, which depends on the pressure in the upper end chamber 87, ie on the bias on the nozzle needle 85. If this preload is increased, the pressure of the upper end chamber 87 increases and the valve spindle 60 is displaced downward. The control edge 70 of the web 62 reaches the edge 86 of the extension 89 on the inner circumference of the valve sleeve 51 in the region of the section 57. The pressure fluid from the line 26 finds one on the control edge 70 15 throttled path in line 12 to the associated support element 10.

The degree of throttling at the control edge 70 and thus the degree of pressure reduction compared to the inlet pressure in the line 26 depend on the elongation of the molded body 90, which is controlled by the computer 40. The inlet pressure in line 26 can be, for example, in the range from 170 to 180 bar, the outlet pressure in line 12 must have at least a value of about 3 to 5 for proper operation of the support element 10

Have bar. The pressure difference at throttle 67 is independent of the inlet pressure in line 26, assuming steady-state conditions. This is important because the response of the valve 50 does not depend on the pressure of the pump 23.

In the exemplary embodiment in FIG. 3, it is a pilot-operated valve that manages with low actuating forces of the shaped body 90. The molded body 90 is not directly connected to the valve spindle 60, but controls the nozzle needle 85 in order to in this way

To bring about power transmission for the control of the valve spindle 60. If the shaped body 90, which changes its shape in at least one dimension, is adequately dimensioned, it would also be possible to direct it with the displacing boundary surface with the valve spindle

60 to connect.

Claims

16P claims

1. roller (100) for the pressure treatment of a web (B) made of paper, textile, nonwoven, plastic film, sheet metal or the like, with a circumferential hollow roller (2) forming the working roller circumference, with a hollow roller (2) lengthways penetrating, all around radial distance to the inner circumference (8) of the hollow roller (2) to be left, at the ends (l ', l') non-rotatably supported on external supports with a crosshead (1) arranged on the crosshead (1) by means of a fluid Pressure medium against the inner circumference (8) of the hollow roller (1) compressible support elements (10), with a pressure medium source (23) and with a control and regulating device (30) for each individual support element (10) or every small one

Group of support elements (10) comprises a valve (50), which is connected to the pressure medium source (23) and can be controlled by means of an actuator which can be continuously displaced by means of an actuator, by means of which each support element (10) or each small group of support elements (10) pressurized medium under one Individual pressure can be supplied, characterized in that the actuator (80) comprises a molded body (90) which is clearly in the presence of an electrical voltage 17

Depending on this changes its extent in at least one dimension.

2. Roller according to claim 1, characterized in that the shaped body is connected directly to the valve member.

3. Roller according to claim 1, characterized in that the shaped body (90) is connected to an auxiliary valve member (85) by means of which the actual valve member (60) is precontrolled.

4. Roller according to one of claims 1 to 3, characterized in that the valve member is a displaceable in the direction of its axis (A) valve spindle (60).

5. Roller according to one of claims 1 to 4, characterized in that the shaped body (90) is connected to a seat valve (75, 85), which the equilibrium position of the valve member (60) under the action of the pressure medium against the force of a spring ( 73) changed.

6. Roller according to one of claims 1 to 5, characterized in that the shape of the shaped body (90) can be changed by an electrochemical effect.

7. Roller according to one of claims 1 to 5, characterized in that the shape of the shaped body can be changed by a piezoelectric effect.

8. Roller according to one of claims 1 to 5, characterized in that the shape of the shaped body can be changed by a magnetostrictive effect.

9. Roller according to one of claims 1 to 5, characterized in that the shape of the shaped body by a 18 can be changed thermoelectrically caused by the applied voltage.

10. Roller according to claim 9, characterized in that the shaped body contains an expansion material.

11. Roller according to one of claims 1 to 5, characterized in that the shape of the shaped body can be changed by a thermoelectrically induced temperature change by means of a temperature-dependent shape memory.