JP5270140B2 - calendar - Google Patents

Abstract

The calendar (1) has a printing device (21) applied against an effective direction of a force unit of a charging pressure. The printing device is connectable and disconnectable in dependence of a load-conditional adjustable line force in a nip (3) that is limited by a bending-controlled roller (4) i.e. end roller. A fluid supply unit e.g. supply lines (17, 18, 22) and delivery line (23), is provided, where the fluid supply unit supplies a hydraulic and/or lubricating medium to bearings (15) and the printing device. The printing device is formed by an annular space.

Description

  The present invention relates to a calendar for processing a product web.

  This type of calendar is known from Patent Document 1 or Patent Document 2, for example. According to it, both or at least one of the two end rolls of the roll stack are configured as deflection control rolls. Deflection control rolls are used to eliminate roll short and long wave shape errors that may result from roll configuration and / or product web to be processed. All shaping is done exclusively hydraulically and can be done with force elements in hydraulic bearing arrangements that are driven in groups or individually. In addition to the correction width and the positioning accuracy, the local linear force correction, that is, the magnitude of the correction potential, has an extremely large influence during the lateral shaping.

  In order to optimize the correction potential, it is known to construct a deflection control roll having at least two successive fully filled force element sequences. In this case, the force elements facing the nip can be driven individually. For this purpose, at least a second row of force elements directed backwards generates a uniform prestress pressure over the entire length of the roll. This uniform prestress pressure from at least the second row of force elements has the effect that the element pressure of the force element opposite the nip is artificially increased. In this way, higher pressure and force reversals can be used for local shape correction. Providing at least a second row of force elements is structurally complex. In addition, deflection control rolls having at least a second row of force elements require a greater driving force, thereby increasing calendar operating costs.

To optimize the correction potential, it can be driven individually and, as a result, known as the annular chamber pressure, in addition to the row of hydraulic force elements facing the nip producing a selectable element pressure The action of an annular space having a prescribed oil pressure between the roll carrier and the roll shell is also known from US Pat. As a result of this interaction of element pressure and annular chamber pressure, two different local force effects can be obtained. If the element pressure is higher than the surrounding annular chamber pressure, the action of the force directed at the nip is brought about by the maximum pressure, or if the element pressure is lower than the surrounding annular chamber pressure, the low pressure area causes the nip to The effect of the separating force is brought about. Thus, the force element can act as both a positive pressure element and a negative pressure element. The disadvantage in this case is that a deflection control roll with an oil-filled annular chamber requires a greater driving force due to vortex loss of oil in the annular chamber.
German Patent No. 32 01 635 C2 German Patent No. 196 50 576 C2 German Patent No. 38 20 974 C3

  Accordingly, it is an object of the present invention to provide a calendar that is inexpensive to operate and requires little maintenance.

In order to achieve the object of the present invention, a calendar according to claim 1 of the present invention is a calendar for processing a product web, and includes at least two rolls for forming a nip capable of loading a linear force. Having at least one roll stack and a deflection control roll as at least one end roll, wherein the deflection control roll is constructed and supported to have a rotatable roll shell penetrated by a fixed support. Is a hydraulic bearing configuration arranged between the part and the roll shell, formed by individual mounting parts arranged adjacent to each other in the axial direction along the roll length, and controlled to the inner peripheral surface of the roll shell, respectively. A hydraulic bearing arrangement having a radially movable force element for applying a possible force element pressure and prestressed against the direction of action of said force element Scan pressure possess at least one pressurizing device may be added, the pressure device from configurable line force 10 in the nip bounded by the deflection control roll to the load of less than 200 N / mm In a calendar that applies or blocks the prestress pressure as a function of the level of required linear force, the deflection control roll constructed with the pressurizing device is repaired adjacent to the inner periphery of the roll shell. A collection chamber having at least one wiper capable of being displaced in position, the wiper being provided with a guide surface and an outlet for receiving the wiped liquid, said outlet being connected to a drain line, The discharge line can be opened or closed by an activation element, and when the prestress pressure is applied by the pressurization device, the activation element It is closed, and characterized in that the activation element is released if the prestressing pressure by the pressure device is cut off.

According to a second aspect of the present invention, the calendar according to the first aspect is characterized in that the wiper can be retracted from a repair position by connecting the pressure device .
The calendar according to a third aspect of the present invention is the calendar according to the first or second aspect, wherein at least one liquid supply section for supplying pressurized and / or lubricating liquid to the mounting section and the pressurizing device is provided. It is characterized by that.
A calendar according to a fourth aspect of the present invention is the calendar according to any one of the first to third aspects, wherein the pressurizing device is formed in an annular space, and an optional hydraulic pressure is applied to the annular space. It can be added between the roll shell and the fixed support portion.

A calendar according to a fifth aspect of the present invention is the calendar according to any one of the first to third aspects, wherein the pressurizing device faces the hydraulic bearing configuration along the deflection control roll. Characterized in that it has a hydrostatic support ram or a hydraulic sealing element directed to the surface.
The calendar according to a sixth aspect of the present invention is the calendar according to the fifth aspect, wherein the static pressure support ram or the hydraulic seal element is constructed so as to be retractable by a mechanical or hydraulic retractor.
A calendar according to a seventh aspect of the present invention is the calendar according to the sixth aspect, wherein the mechanical retracting device provided is a tension spring.

A calendar according to an eighth aspect of the present invention is the calendar according to any one of the first to seventh aspects, wherein the force element is constructed as a static pressure support ram .
A calendar according to a ninth aspect of the present invention is the calendar according to any one of the first to eighth aspects, wherein the force element is constructed as a hydraulic seal element .

A calendar according to a tenth aspect of the present invention is the calendar according to any one of the first to ninth aspects, wherein the activation element is a valve .

The object of the invention is achieved by the features of claim 1.
According to the calendar according to the invention, the shape error as a function of the level of the line force required for the load that can be set in the nip bounded by the deflection control roll by connecting and disconnecting the pressure device. A calendar is created that increases the correction potential of. Roll geometric errors and shape errors caused by the product web can be corrected, specifically thickness differences, mass differences per unit area, and lateral moisture differences of the roll.

  Also, according to the present invention, as will be appreciated, the level of pre-stress pressure or annular chamber pressure is incidental to the driving force consumed. The oil in the annular chamber will certainly increase the driving force and cause a large vortex loss. The pressurizing device serves to pass additional oil through the annular chamber of the deflection control roll. If the second row of at least one force element is preferably constructed, friction loss occurs and additional oil enters the annular space of the roll. If an oil-filled annular chamber or oil-filled annular space is preferably formed, a particularly large amount of oil is present in the roll. According to the present invention, the annular space is thus passed through a pressure device that generates a force directed away from the nip and additionally reaches the annular space of the deflection control roll only in a specific mode of operation of the calendar. Oil that falls within is provided.

In order to reduce the driving force, at least one deflection control roll is constructed to have two modes of operation, specifically with a pressurizing device that can be connected or disconnected. The appropriate operating mode is activated by the line force currently provided in the calendar. This minimizes the energy required for calendar operation. As a result, the driving force can be reduced to 30% at a high web speed of about 2000 m / min.
It is preferred that the pressurization device be connected only to provide a correction potential sufficient for line force correction with a small line force. By means of the element pressure of the force element, a so-called low pressure region can be generated against prestress by the pressurizing device.

In the region of higher linear forces, the correction potential of the deflection control roll itself can be based on the element pressure of the force element. In that case, the element pressure is sufficiently high, and the hydraulic pressure of the force element can be reduced for negative shape correction. In accordance with the present invention, therefore, an additional pressurization device is provided that generates a correction potential to be interrupted. Depending on the paper, a higher linear force is considered in the range of values 10 to 200 N / mm.
More preferably, when the pressurizer is shut off by the connection and disconnection of the pressurizer, it turns into a repair position adjacent to the inner periphery of the roll shell, and when the pressurizer is connected, it leaves the repair position. An adjustable wiper that can swivel is controlled. Particularly preferably, the positioning of the wiper is performed in a self-controllable manner by the ability to connect and disconnect the pressure device.

More preferably, the pressurization device is formed by a hydrostatic support ram oriented backwards relative to the hydraulic bearing arrangement and / or by an annular space between the roll shell and the support, as desired thereto Hydraulic pressure can be applied. A pressurizing device with a support ram allows for a uniform or locally non-uniform prestress pressure setting, but increases the cost of construction. The oil pressure that can be set in the oil-filled annular space requires a uniform prestress pressure. However, a large correction potential is set by a simple structure.
The force element and the pressurizing device are preferably operated hydraulically, for which purpose at least one liquid or oil supply is provided. In this case, the force element can be constructed as a static pressure support element or a sealing element.

The invention will be described in more detail below using the exemplary embodiments shown in the accompanying figures.
FIG. 1 shows a calendar 1 for processing a product web, in particular a paper or paperboard web, or a tissue web, having at least one roll stack 2.
The roll stack 2 has at least two rolls, and a nip 3 is formed between the two rolls so that a linear force can be applied each time. Although not shown, the product web passes through one or more nips 3 at a specific web speed and is subjected to pressure treatment and, where appropriate, temperature treatment. For the purpose of product web duplex processing, the at least one roll stack 2 can have a selectable number of rolls with a reversing roll nip, or at least two roll stacks arranged one behind the other or side by side. Preferably, so that changes on the product web side occur between at least two roll stacks. The load surface can be designed to have an optional tilt angle with respect to vertical, horizontal or vertical.

  At least one end roll of the roll stack 2, in this figure the bottom roll of the roll stack 2, is constructed as a deflection control roll 4. A conventional hard or soft roll 9 is placed adjacent to the deflection control roll 4 to form a hard or soft nip 3 with the deflection control roll 4. The deflection control roll 4 can likewise be constructed as a hard or soft roll. The number of nips 3 of the roll stack 2 can be selected and depends on the type of product web, specifically the paper grade and supercalendering parameters. Furthermore, it is possible to provide two roll stacks each having two deflection control rolls 4 forming a nip 3. The roll may be hard and / or soft.

  The deflection control roll 4 has a rotatable roll shell 5, and the outer periphery 6 of the roll shell 5 forms the circumference of the working roll. The roll shell 5 is constructed as a roll tube or roll shell. A fixed support portion 7, which is a fixed main girder arranged at a distance from the inner periphery 8 of the roll shell 5, passes along the length of the roll shell 5. The roll shell 5 surrounds the annular space 12, and the support portion 7 is disposed in the annular space 12. The support 7 is mounted so that its ends 10 are not rotatable in the bearing 13 each time, and can be turned when appropriate.

The bearing 13 of the deflection control roll 4 and the journal 11 of the conventional roll 9 can be guided in a roll stand (not shown) and pressed against each other by a load device (not shown). As a result, the line force required for the load can be set. As an alternative or in addition, the load can also be set by the displacement of the roll shell 5 relative to the support 7.
The roll shell 5 can be rotated with respect to the support part 7, and for that purpose, the roll shell 5 is supported at both ends of the edge bearing unit 14 each time.

  Between the support part 7 and the roll shell 5, a hydraulic bearing arrangement 15 for supporting the roll shell 5 along at least one active range is arranged. The hydraulic bearing arrangement 15 is formed by individual mountings arranged axially adjacent to each other along the length of the roll, each applying a controllable element pressure to the shell inner peripheral surface 8 of the roll shell 5. A force element 16 which is movable in the radial direction. A pressure adjustable from the pressure medium is applied to the force element 16 each time, so that the force element 16 can be moved in a hydraulic direction radially in the blind hole 19 of the cylinder and on the inner circumference 8 of the roll shell 5. A suitably shaped end face 20 can be formed as a bearing piston element. A force element 16 is provided for applying pressure between the roll shell 5 and the support 7. In particular, depending on the configuration of the force element 16, a pressure medium is used for contact pressure or static pressure, for example as a static pressure support element or seal element having a common or separate liquid supply via supply lines 17, 18. Can do. The force element 16 faces the nip 3.

  The deflection control roll 4 further comprises at least one pressure device 21, whereby a prestress pressure can be applied against the direction of action of the force element 16. The prestress pressure is directed backwards in the reverse direction with respect to the pressing direction of the force element 16. The pressure device 21 can be connected or disconnected as a function of the linear force level required for the load that can be designed in the nip 3 bounded by the deflection control roll 4. It is preferable that the pressurizing device 21 can be connected with a linear force of 10 to 200 N / mm, specifically 20 to less than 100 N / mm required for the load.

  According to the first embodiment, the pressure device 21 is formed by the annular space 12, and an optional hydraulic pressure can be applied between the roll shell 5 and the support portion 7. Although not shown, the annular space 12 is sealed by shaft seals at both ends, and can be filled with pressurized liquid from the storage container 24 via the supply line 22. The pressurized liquid in the storage container 24 can be returned via the conduit 23. A pressure limiting valve 25 is present in the conduit 23 so that a predefinable pressure known as the annular space pressure can be set and maintained in the annular space 12. The pressurized liquid is removed from the storage container 24 and conveyed and is pressurized to preferably 40 to 60 bar by a pump 26 connected to the supply line 22. Due to the annular space pressure, a prestress is generated in which the deflection control roll 4 draws its correction potential. Because of the interaction between the element pressure and the annular space pressure, two different local force effects, i.e. the pressure zone directed to the nip 3 if the element pressure is higher than the surrounding annular space pressure, or the element pressure is ambient This is because when the pressure is lower than the annular space pressure, a low pressure region can be generated. In a region where the linear force required for the load is high, specifically in a region where the linear force exceeds 20 to 100 N / mm, the correction potential of the deflection control roll 4 can be extracted only from the element pressure. In that case, the element pressure is sufficiently high, and the hydraulic pressure of the force element 16 can be reduced due to a negative shape error. In that case, the generation of the low pressure region by the pressurizing device 21 is unnecessary. Therefore, the pump 26 can be switched on and off to activate the pressurizing device 21.

FIG. 4 is a diagram schematically showing a vortex generated in the annular space 12 during oil filling and related to absorption of driving force. FIG. 7 shows the driving force as a function of speed. The broken line shown in the figure is the driving force in a state where the pressure device is connected. The continuous line indicates the driving force in a state where the pressurizing device is shut off. Below a web speed of 500 m / min, the absorption of the driving force is approximately equal in both cases. When the web speed is about 2000 m / min, the driving force is reduced by about 30% when the rate of force absorption caused by the pressurizer, specifically the vortex loss and / or friction loss, is omitted.
Finally, the pressure medium can be supplied to the blind holes 19 of each cylinder of the force element 16 individually or in zones via the supply lines 17, 18, and the supply is effected via the control device 35. Is called. The pressure medium can be removed from the storage container 24 and pressurized with the pump 36.

  According to the second exemplary embodiment shown in FIGS. 5 and 6, the pressure device 40 has a hydrostatic support ram 37 oriented rearward with respect to the force element 16, the support ram 37 being Produces a uniform prestress and is therefore arranged in rows adjacent to each other. Alternatively, the support ram 37 can be constructed as a hydraulic seal element. The static pressure support ram 37 is preferably connected to a common supply line 22 and discharge line 23. The support ram 37 can be connected or disconnected. Isolation is effected by pulling the support ram 37 back, thereby causing mechanical and hydraulic friction losses that can absorb the driving force of the roll 4 as well as during support on the inner circumference 8 of the roll shell 5. Occurrence of oil overflow is avoided. FIG. 6 shows the retracted position of the support ram 37 in the annular space 12 so that there is no contact with the inner periphery 8 of the roll shell 5.

  The hydrostatic support ram 37 can generate a force along the length of the roll that is directed away from the nip, similar to the oil-filled annular space 12 where the hydraulic pressure is increased. Although the oil-filled annular space 12 has the advantage of maintaining a substantially circular shape regardless of the force set in the direction in which the roll shell 5 leaves the nip, the hydrostatic support ram 37 allows the roll shell 5 to Is set in a direction away from the nip, it is deformed from a circular shape. The static pressure support ram 37 can be constructed in a known manner. To retract the support ram 37, a mechanical or hydraulic retractor can be provided. According to FIG. 6, the mechanical retracting device can be formed, for example, by a tension spring 41.

  As previously described in connection with the exemplary embodiment of FIGS. 1-4, it is preferred that the wiper 27 can be retracted or retracted from the repair position by connection of the pressure device 40. If it is not desirable for the wiper 27 to be permanently placed in the repair position, when the mechanical or hydraulic retractor 41 is activated, i.e. when the support ram or hydraulic seal element is deactivated, The wiper 27 is set to the repair position. This can be done in a self-controlling manner or by combining the activation of the wiper with the activation of the retracting device.

  The deflection control roll 4 constructed with the pressure devices 21, 40 has at least one wiper 27 that can be displaced into a repair position adjacent to the inner circumference 8 of the roll shell 5. The wiper 27 is disposed in the annular space 12. The present invention provides a wiper 27 that is configured such that when the pressurizing devices 21 and 40 are connected, the wiper 27 is retracted from the repair position, and specifically turned back. It is particularly preferred that the ability to be retracted from the repair position is provided in a self-controlling manner. For this purpose, the wiper 27 preferably has an actuating device 28 responsive to the activation of the pressurizing devices 21, 40. According to the exemplary embodiment shown in FIGS. 1 to 6, the wiper 27 is constructed as a two-armed lever. In this figure, a lever arm that can be aligned in a repair position adjacent to the inner circumference 8 of the roll shell 5 is attached to a tension spring 29. Actuator 28, such as an inflatable hose, operates against the attractive force of tension spring 29 and is connected to an air supply line 30 having a pump 31. When the annular space 12 is filled with oil, as shown in FIG. 3, in this case, the actuator 28 is deactivated by compressing the hose, and the wiper 27 is repaired by the attractive force of the tension spring 29 (see FIG. 3). 2). The wiper 27 can be constructed to be displaceable in addition to being constructed so as to be able to turn.

  The wiper 27 is provided with a collection chamber 33 having a guide surface 34 and an outlet 32 for receiving the wiped liquid. The outlet 32 is preferably connected to a drain line 38, which can be opened or closed as desired by the activation element 39. When the pressure devices 21, 40 are connected, the activation element 39 is closed. When the pressurization devices 21 and 40 are shut off, the activation element 39 is opened. The actuating element 39 used can in particular be a valve.

FIG. 3 is a schematic diagram showing a small region of a calendar having a deflection control roll partially shown in longitudinal section as an end roll, according to a first exemplary embodiment. FIG. 2 is a schematic cross-sectional view taken along line A-A in FIG. 1 in a state where the wiper is turned to a repair position. FIG. 2 is a schematic cross-sectional view taken along line A-A in FIG. 1 with the wiper being pivoted away from the repair position. FIG. 2 is a schematic cross-sectional view taken along line A-A in FIG. 1 with the wiper pivoted away from the repair position in a self-controllable manner. FIG. 6 is a schematic diagram showing a small area of a calendar having a deflection control roll partially shown in longitudinal section as an end roll, according to a second exemplary embodiment. FIG. 6 is a schematic cross-sectional view of FIG. 5 in a state where the wiper is turned to a repair position. 6 is a graph showing the driving force as a function of the speed of a deflection control roll connected and shut off by a pressure device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Calendar 2 Roll stack 3 Nip 4 Deflection control roll 5 Roll shell 6 Outer periphery 7 Support part 8 Inner periphery 9 Conventional roll 10 End part 11 Journal 12 Annular space 13 Bearing 14 Edge bearing unit 15 Hydraulic bearing structure 16 Force element 17, 18 Supply line 19 Cylinder blind hole 20 End face 21, 40 Pressurization device 22, 23, 38 Discharge line 24 Storage container 25 Pressure control valve 26, 31, 36 Pump 27 Wiper 28 Actuator 29 Tension spring 30 Air supply line 32 outlet 33 collection chamber 34 guide surface 35 control device 37 hydraulic sealing element 39 activation element 41 retracting device

Claims (10)

A calendar for processing a product web having at least one roll stack having at least two rolls forming a nip capable of loading a linear force and a deflection control roll as at least one end roll. The deflection control roll is constructed to have a rotatable roll shell that is penetrated by a fixed support portion, and is a hydraulic bearing configuration disposed between the support portion and the roll shell, along the length of the roll. A hydraulic bearing structure formed by individual mounting portions arranged adjacent to each other in the axial direction and having a radially movable force element for applying a controllable force element pressure to the inner circumferential surface of the roll shell. If, possess at least one pressurizing device may be added prestressing pressure counter to the direction of action of the force element, the Pressure device shuts off or add the prestressing pressure as a function of the deflection controlled roll by a configurable line force 10 in the nip bounded 200 N / below mm line force required to load level In the calendar, the deflection control roll constructed to have the pressure device has at least one wiper that can be displaced into a repair position adjacent to the inner periphery of the roll shell and guides it to the wiper. A collection chamber is provided having a surface and an outlet for containing the wiped liquid, said outlet being connected to a discharge line, which can be opened or closed by an actuating element, The activation element is closed when the prestress pressure is applied, and the prestress pressure is blocked by the pressurizing device Calendar, characterized in that said activation element is open. The calendar according to claim 1 , wherein the wiper can be retracted from a repair position by connecting the pressure device .   3. The calendar according to claim 1, further comprising at least one liquid supply unit configured to supply pressurized and / or lubricating liquid to the attachment unit and the pressurizing device.   The pressurizing device is formed in an annular space, and an optional hydraulic pressure can be applied to the annular space between the roll shell and the fixed support portion. Calendar described in the section.   4. The pressurizing device comprises a hydrostatic support ram or a hydraulic seal element oriented rearwardly with respect to the hydraulic bearing arrangement along the deflection control roll. The calendar according to one item.   6. A calendar according to claim 5, wherein the hydrostatic support ram or hydraulic sealing element is constructed to be retractable by a mechanical or hydraulic retractor.   The calendar according to claim 6, wherein the mechanical drawing device provided is a tension spring. The calendar according to claim 1, wherein the force element is constructed as a static pressure support ram . 9. A calendar according to any one of the preceding claims, wherein the force element is constructed as a hydraulic seal element . The calendar according to claim 1, wherein the activation element is a valve .

Images