EP2516737A1

EP2516737A1 - Assembly for controlling the position of a roll or the gap pressure of a roll gap in a fibrous material web machine

Info

Publication number: EP2516737A1
Application number: EP10763181A
Authority: EP
Inventors: Ville Hopponen; Arto Ikonen
Original assignee: Metso Paper Oy
Current assignee: Valmet Technologies Oy
Priority date: 2009-12-23
Filing date: 2010-10-05
Publication date: 2012-10-31
Anticipated expiration: 2030-10-05
Also published as: JP2013515867A; CN102666981A; JP5719853B2; DE102009055308A1; WO2011076453A1; EP2516737B1; CN102666981B

Abstract

The invention relates to an assembly for controlling the position of a roll or the gap pressure of a roll gap, in particular in a fiber web machine, for example a paper, cardboard or tissue machine. The assembly according to the invention comprises at least one actuator (4, 5) driven by fluid pressure for varying the roll position or the roll gap pressure, at least one digital valve regulator (1) connected to the at least one actuator (4, 5) or to a plurality of actuators (4, 5) that are driven by fluid pressure, and at least one first digital, normally open shut-off valve (15, 16, 17, 18). The at least one shut-off valve (15, 16, 17, 18) is provided between the regulator and the actuator, and the at least one pressure regulator comprises a plurality of digital valves and can control a fluid pressure and/or a fluid flow. The invention further relates to related control methods and diagnostic and maintenance methods.

Description

Arrangement for controlling the position of a roll or the nip pressure of a nip in one

Fibrous web machine "

TECHNICAL AREA

The present invention relates to an arrangement for controlling the position of a roll or the nip pressure of a nip formed between two rolls in a machine for producing or treating a roll

Fiber web, in particular in a paper, board or Tissuemaschine, and in particular to an arrangement in which a digital valve is provided as a switching valve between a fluid pressure driven actuator and a digital valve controller which controls the actuator. Moreover, the present invention relates to

Control methods as well as on diagnostic and

Maintenance method for such an arrangement.

STATE OF THE ART

An existing digital valves regulator, the one

Hydraulic actuator by changing a

Hydraulic fluid pressure or a hydraulic fluid flow controls to a position of a roller of a

Nip forming roller pair and a

Is to adjust roll pressure in the nip is

For example, from DE-A-103 93 693 known.

The term "digital valve" stands for a valve which, between two consecutive states, directly from the first state, for example the fully opened state, into the second state, for example the

completely closed state, and can be moved back. When the digital valve is fully open is, it is flowed through by the total volume flow rate of the fluid flow permitted by this valve. In the fully closed state, however, the valve does not flow through the fluid. Such a digital valve is therefore also referred to as on-off valve or on-off digital valve.

A digital valve module constructed of such on-off digital valves may therefore have N ² flow conditions, where N is the number of

Digital valves in the digital valve module is. One

Digital valve module of a regulator described above, the twelve digital valves, each with different

Volume throughputs, therefore achieves a maximum control resolution of 2 ¹² different

Volume throughputs, so 4096 different

Volume throughputs. This achieves a good approximation to the continuous adjustment of the volume flow rate of known servo or proportional valves. As contained in a single digital valve module

Digital valves have only two states (open or closed), they work very fast compared to known servo or proportional valves. There are also digital valves known that have more than two states

have, for example, a digital valve with three

Positions, wherein the valve in the first position allows the flow in one direction, in the second

Position allows the flow in another direction, and in the third position does not allow flow or prevents flow (off state).

Those used in the regulator of DE-A-103 93 693

Digital valves are in one or more

Digital valve packages or digital valve modules arranged and allow precise control of the with the Piston rod of the hydraulic cylinder roller connected by the hydraulic pressure to the hydraulic chambers of the hydraulic cylinder fluid pressure or fluid flow can be controlled digitally, ie stepwise by opening a desired number of digital valves. The

Digital valves in the controller each have different throughputs through differently sized passage openings of the individual digital valves. As a result of different combinations of the digital valves with the differently sized passage openings, different fluid flow volumes to the hydraulic cylinder with a wide resolution, i. with a large number of

various possible throughput volumes are passed.

The pressure of the hydraulic fluid in the hydraulic cylinder is thus by opening one or more suitable

Digital valves regulated, wherein the passing through the valves fluid flow is usually doubled each time it passes from a digital valve to the next larger digital valve. In other words, the maximum possible volume throughput of a

Digital valve always twice the maximum possible volume throughput of the previous switched

Digital valve. If the nip pressures to be achieved are known, all occurring during operation

Nip pressures by a predetermined number of suitable digital valves in one

Digital valve module can be adjusted accordingly.

Among the on-off digital valves, among others, two different types are well known, namely the normally closed digital valves shown in schematic

Drawings are usually marked with NC (from the English term "normally closed"), and the normally open digital valves, usually with NO (from The normally closed digital valves are valves which, in a non-actuated state, for example in a state in which, for example, no current is supplied to a switching electromagnet, by a spring or the like in a

closed position (off position) are urged.

On the other hand, normally open digital valves are valves which are in an unactuated state, e.g. in a state in which, for example, no power is supplied to a switching electromagnet, are urged by an spring or the like to an open position (on position).

Significant advantages of digital valves compared to conventionally used servo or

Proportional valves are among other things an exceedingly

fast response, the simple construction of the

Digital valves and their low energy consumption, since no continuous flow of hydraulic fluid through the valves is required.

In the field of fiber web manufacturing, particularly paper or board making, the use of digital valves in pressure or flow regulators holds up

Hydraulic devices move in a short time. By replacing conventional continuously adjustable servo or proportional valves in paper, cardboard or

Tissue machines, and in particular when using known digital valves in controllers for

Hydraulic devices in paper, cardboard or

Tissuemaschinen but it comes to new problems.

Among other things, it is a problem of digital valves that specifically when using electrically operated

Digital valves a power failure or a malfunction of the regulator can cause a through digital valves controlled hydraulic device, which in one

Fiber web machine, for example, determines the position of a roller, can not be reset to a starting position. A nip, which is formed inter alia by this roller, so it can not be opened in case of power failure. For example, then a passing through the nip fiber web can not be removed from the nip.

In addition, digital valves must be in one

Digital valve regulators are regularly checked for correct operation by means of maintenance routines. During these maintenance routines, which are usually carried out during operation of the fiber web machine, the hydraulic device to be controlled must therefore be completely separated from the digital valve controller, without affecting the function of the hydraulic device.

Ultimately, it is a general problem that each to be replaced servo or proportional valve in one

Fiber web machine is replaced by a variety of digital valves. The number of valves required therefore increases many times, resulting in the statistical error rate of the hydraulic control in the

Fiber web machine undesirably increased.

The present invention is therefore the task

underlying, an improved arrangement for the regulation of

Position of a roll or the nip pressure of a

Roll nips and control methods as well as diagnostic and maintenance procedures for the improved arrangement

provide, eliminating the previously mentioned

Problems are solved. This object is achieved by an arrangement with the features of claim 1 and a control method having the features of claim 15 or 17 and a diagnostic and maintenance method having the features of claim 22.

SUMMARY OF THE INVENTION

An arrangement according to the invention for controlling the position of a roller or the nip pressure of a roller gap formed between two rollers, in particular for a roller

Fiber machine such as a paper, cardboard or paper

Tissue machine, has at least one

fluid pressure driven actuator for changing the

Roller position or the nip pressure on. The actuator is preferably a hydraulic cylinder, more specifically an oil hydraulic cylinder, which may be connected directly to a roll of paper, board or Tissuemaschine, wherein the force of the hydraulic cylinder and thereby to control the position of the roller or a pressure in a nip is, inter alia, by the roller

is trained. Furthermore, the arrangement according to the invention has at least one digital valve controller connected both to a fluid pump with pressure accumulator and to a fluid collecting container (tank or accumulator). The controller is doing with the at least one

fluid pressure driven actuator or with several

fluid pressure driven actuators connected and has a plurality of digital valves, which serve a fluid pressure acting in the actuator by adjusting the passing through the individual digital valves

To control fluid flow rate.

The regulator preferably comprises at least two

Digital valve modules, each with a variety of

Digital valves, wherein a digital valve module with a rod-side hydraulic chamber acting as an actuator hydraulic cylinder and the other digital valve module with a piston-side hydraulic chamber of the hydraulic cylinder may be connected, so that a translational

Adjusting movement of the hydraulic cylinder by a targeted control of the rod-side hydraulic chamber and / or the piston-side hydraulic chamber takes place. each

Digital valve module preferably has several

Digital valves, more preferably twelve digital valves, wherein the controller as needed, more than two digital valve modules, each with more than twelve

May have digital valves.

In addition, the arrangement according to the invention also has at least one first digital, normally open shut-off valve, which is provided in each case between regulator and actuator. It is also conceivable an arrangement in which a digital shut-off valve between each digital valve module of

Regulator and connected to this digital valve module hydraulic chamber is provided. The at least one first digital shut-off valve can be a hydraulic

be controlled / operated digital valve whose

Hydraulic supply preferably by a control valve

is controlled. Such a control valve may be an electromagnetically actuated, normally closed

Be digital valve. Instead of the electromagnetic

But actuable digital valve can also be used any other type of control valve.

Further preferably, a normally closed

Digital valve provided between the two digital valve modules of the regulator, which serves as a digital connection valve. Through this connection valve, a connection between the line leading from the one digital valve module to the rod side hydraulic chamber, and the

Lead produced by the other

Digital valve module to the piston-side hydraulic chamber leads. By such a construction, when all digital valves of both digital valve modules are closed and the connecting valve is opened, a direct connection between the piston-side hydraulic chamber and the rod-side hydraulic chamber of the hydraulic cylinder can be established, so that hydraulic pressure of the hydraulic chambers without external hydraulic fluid supply or exhaustion can be made only by reference to FIG the chambers present different hydraulic pressures can be adjusted.

The arrangement according to the invention also has

preferably at least one second digital

Shut-off valve, which is provided in parallel with each first digital shut-off valve. The second digital

Shut-off valve is preferably a normally closed digital valve. By this arrangement, a

Parallel connection of a normally closed digital valve and a normally open digital valve are used between the controller or a digital valve module of the controller and the hydraulic cylinder or each

Hydraulic chamber of the hydraulic cylinder is arranged.

In principle, in the inventive arrangement instead of a hydraulic cylinder, as in the

previously described arrangement by way of example

is provided, two or more parallel hydraulic cylinders to be connected to the controller, to which the system described above is adapted. Thus, for example, a first digital shut-off valve may be provided between each digital valve module of the regulator and each hydraulic chamber, and / or one or more connecting valves previously described may interconnect the conduits to the hydraulic chambers provided by the further hydraulic cylinders. Further preferably, a pressure sensor and / or a flow sensor or the like is respectively arranged between the at least one first shut-off valve and the at least one hydraulic cylinder or a hydraulic chamber of the hydraulic cylinder, whereby a regulation of the hydraulic pressure in the cylinder is made possible.

Furthermore, it is preferable that the controller, i.

at least one of the digital valve modules or even each digital valve module of the controller has at least one normally open digital valve that can serve as a safety valve. With such a safety valve, a possibly necessary discharge of fluid through the regulator is ensured in the event of a power failure, a malfunction of the regulator or the like. As a result, to date used emergency power supplies or

the like superfluous.

With the arrangement according to the invention, as described above, among other things, various control and diagnostic methods of the controller can be

realize. A first invention

Control method for an arrangement according to the invention for controlling the position of a roll or the nip pressure of a nip formed between two rolls, in particular in a paper, board or tissue machine, has the following steps:

- Opening a certain number of digital valves

a digital valve module of the digital valve controller, wherein the number of open digital valves depends on the desired fluid flow;

- opening at least one first digital

Abschaltventils, between the one partially or fully opened digital valve module and a to be controlled by this digital valve module

Hydraulic chamber of a first to be controlled

Hydraulic cylinder is provided, wherein the

is to be controlled hydraulic chamber by opening the desired shut-off valve;

- Supplying hydraulic fluid to the controlled

Hydraulic chamber until a desired hydraulic pressure is reached in the hydraulic chamber to be controlled, whereby the piston rod of the hydraulic cylinder is moved and the translational position of a

associated roller, for example in the course of a

Change in position of the roller is changed; and

Closing the shut - off valve so that one of the

to be controlled hydraulic chamber supplied

Hydraulic pressure and thereby a position of

Piston rod and thus the driven roller is maintained.

With such a control method, it is possible by means of digital valves a fast, targeted

To achieve control of a hydraulic cylinder, wherein a once set pressure in a hydraulic chamber of the hydraulic cylinder by closing the hydraulic chamber upstream shut-off valve can be maintained without further digital valves must be permanently activated. This type of control is therefore energy efficient and inexpensive.

In the first control method according to the invention, a further hydraulic cylinder can preferably be connected to the controller in parallel to the first hydraulic cylinder. In such a parallel arrangement are a

rod-side hydraulic chamber of the first

Hydraulic cylinder and a rod-side hydraulic chamber further hydraulic cylinder with the same

Digital valve module connected to the regulator, and a

The piston-side hydraulic chamber of the first hydraulic cylinder and a piston-side hydraulic chamber further

Hydraulic cylinders are connected to the same digital valve module of the controller. Furthermore, an arrangement in which a rod-side hydraulic chamber of the first

Hydraulic cylinder and a piston-side hydraulic chamber of the further hydraulic cylinder with the same

Digital valve module of the controller are connected, so a cross-arrangement as an alternative also conceivable.

In the first control method according to the invention, the opening step preferably further comprises

at least one first shut-off valve, an opening of a further first digital shut-off valve, which is arranged between the one digital valve module and a parallel-connected hydraulic chamber of the further hydraulic cylinder. This means that at the step of opening

at least one first shut-off valve, the lines between the parallel with the digital valve module

connected hydraulic chambers of the first and further hydraulic cylinder and the corresponding

Digital valve module to be opened.

Furthermore, in the first invention

Control method the step of dispensing

Hydraulic fluid to the hydraulic chamber to be controlled preferably a parallel supply of hydraulic fluid to the hydraulic chamber connected in parallel, so that at the same time to the parallel hydraulic chambers, a hydraulic fluid through the connected to the digital valve regulator pressure accumulator, for example. The pump is supplied. In this case, the step of

Closing the shut-off valve preferably closing all in the arrangement existing shut-off valves, so that a hydraulic chambers to be controlled all supplied

Hydraulic pressure can be maintained without accepting pressure losses. This makes it possible to have several

To control hydraulic cylinder by one and the same digital valve module and to generate a desired hydraulic pressure in the controlled hydraulic chambers of the hydraulic cylinder, by closing the shut-off valves

is maintained without requiring further fluid flow through the valves. That means one

Control of the hydraulic cylinder on the basis of how

previously described arranged digital valves can be achieved by an energy-saving and therefore cost-effective method.

A further control method according to the invention for an arrangement according to the invention for controlling the position of a roll or the nip pressure of a nip formed between two rolls, in particular in a paper, board or tissue machine, comprises the following steps:

- closing all digital valves of a digital valve regulator comprising two digital valve modules;

- Opening a digital connection valve, which is a line connected to a digital valve module of the

Digital valve controller leads to a hydraulic chamber of a first hydraulic cylinder, connected to a line that from the other digital valve module of the controller to the other hydraulic chamber of the

Hydraulic cylinder leads; and

- opening at least one first digital

Shut-off valve, wherein in each case a shut-off valve between the one digital valve module and the one hydraulic chamber and between the other Digital valve module and the other hydraulic chamber is provided.

In the further control method according to the invention, a hydraulic pressure is applied directly by the step of opening the at least one first digital shut-off valve

transferred between the hydraulic chambers of the hydraulic cylinder or exchanged, without an external

Pressure accumulator relied to provide the required fluid pressure. This can be an even faster

Control of a hydraulic chamber based on an existing hydraulic pressure of the other hydraulic chamber can be achieved without the controller accordingly

must be controlled. In addition, through this

Control method a pressure based on a single

Digital valve compared to a variety of

Digital valves are controlled in the controller, whereby an energy-saving pressure control is realized.

In the case of the further control method according to the invention, a further hydraulic cylinder is preferably connected to the regulator parallel to the first hydraulic cylinder, similar to that already in the case of the first invention

Control method is described.

Furthermore, the step of opening at least one first digital shut-off valve preferably comprises opening at least one further first digital shut-off valve, which is respectively provided between the one digital valve module and the one hydraulic chamber of the further hydraulic cylinder and between the other digital valve module and the other hydraulic chamber, so that hydraulic pressure between the hydraulic chambers of the hydraulic cylinders

can be exchanged or transmitted with each other. In the previously described first and second inventive control method is further

Preferably, a second digital shut-off valve is arranged parallel to the first digital shut-off valve, and the step of opening at least one digital

Shut-off valve preferably includes an opening of the first digital shut-off valve and the second digital

Shutdown valve, so that a hydraulic pressure can be passed through the parallel cut-off valves simultaneously. The first digital shut-off valve may be a normally open digital valve, and the second digital shut-off valve may be a normally closed shut-off valve, so that the first digital shut-off

Shutdown valve as a safety valve for one

Power failure, malfunction or the like can serve to allow a possibly desired discharge of fluid from the cylinder.

Furthermore, it is possible with the inventive arrangement, an inventive diagnostic and

Perform maintenance procedures. This method for an arrangement according to the invention for controlling the position of a roll or the nip pressure of a nip formed between two rolls, in particular in a paper, board or tissue machine, has the following steps:

Closing at least one digital shut-off valve, which between at least one of a digital valve module and a hydraulic chamber to be controlled

Hydraulic cylinder is provided;

- Opening all digital valves at least one

Digital valve module of the digital valve controller according to a certain switching sequence and supplying the regulator with fluid, wherein a diagnostic circuit sequence the digital valves a known driving to

Capability checking of the digital valves; and

- Determining a faulty digital valve on the basis of the exiting the regulator fluid flow, wherein by the step of closing the digital

Shut-off valve between digital valve module and

Hydraulic chamber hydraulic pressure during the diagnosis and maintenance process can be maintained without pressure loss.

The described diagnosis and maintenance method can thus be carried out during operation of the hydraulic cylinder without adversely affecting its functionality

or temporarily disable the hydraulic cylinders. A smooth operation of the

Fiber web machine can be guaranteed.

In the diagnostic and maintenance method according to the invention, the shut-off valve can be a hydraulically controlled

Digital valve whose hydraulic supply is preferably controlled by a control valve. The control valve may further preferably be an electromagnetic

be actuated, normally closed digital valve, which includes the step of closing the at least one

Shut-off valve controls. It is through this structure

possible, multiple hydraulic shut-off valves simultaneously using only one electromagnetically controlled

Close digital valve or open. As a result, a power-saving, cost-effective and yet rapid diagnosis and maintenance procedure can be implemented.

Other objects, advantages and aspects emerge from the dependent claims, the description of

Embodiments and the drawings. The invention is described below with reference to

Embodiments described in more detail with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic drawing of a

inventive digital valve controller, with two

Hydraulic cylinders is connected; and

Fig. 2 is a schematic view of another

Digital valve controller connected to two parallel hydraulic cylinders.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In Fig. 1 is an arrangement with a digital valve controller

1 with four digital valve modules 11, 12, 13, 14, their respective common input line to a pump

2 and their respective common output line are connected to a fluid collecting container 3. each

Digital valve module 11, 12, 13, 14 consists of a total of twelve digital valves, with the common

Input line connected input side of each

Digital valve module 11, 12, 13, 14 with six normal

closed (NC) input digital valves is connected. The six normally closed (NC) input digital valves open into a common supply line 111, 121, 131, 141, which in turn is provided with five normally closed (NC) output digital valves and a normally open (NO) output digital valve 112, 122, 132 , 142, wherein the output digital valves via the output side of each digital valve module 11, 12, 13, 14 in the common Lead out output line. The normally open (NO) output digital valve 112, 122, 132, 142 of each

Digital valve module 11, 12, 13, 14 serves as

Safety valve 112, 122, 132, 142, the at a

Power failure, malfunction or the like

Draining the fluid to be controlled allows.

The supply lines 111, 121, 131, 141 are each a normally open (NO) digital valve 15, 16, 17, 18 with a hydraulic chamber 41, 42, 51, 52 of a

Hydraulic cylinder 4, 5 connected. More specifically, the supply line 111 of the digital valve module 11 via the acting as a shut-off valve digital valve 15 with the

The supply line 121 of the digital valve module 12 is connected via the digital valve 16 acting as a shut-off valve with the piston-side hydraulic chamber 41 of the

Hydraulic cylinder 4 connected to the supply line 131 of the digital valve module 13 via the digital valve acting as a shut-off valve 17 connected to the rod-side hydraulic chamber 52 of the hydraulic cylinder 5, and the supply line 141 of the digital valve module 14 is also acting as a shut-off valve digital valve 18 with the

piston-side hydraulic chamber 51 of the hydraulic cylinder 5 is connected.

In operation, the hydraulic cylinders 4, 5, in a

Fiber-web machine, in particular a paper, board or tissue machine ^¬ usually for positioning a roller (not shown) are used, either the piston-side, depending on the movement of the roll to be positioned

Hydraulic chamber 42, 52 of the cylinder 4, 5 for

Forward movement of the roller or the rod side

Hydraulic chamber 41, 51 of the cylinder 4, 5 for

Backward movement of the roll with hydraulic fluid pressure applied. The desired hydraulic fluid pressure supplied by the pump 2 is via an on-off combination of the digital valves of each

Digital valve module 11, 12, 13, 14 precisely adjusted, as described earlier. A

Regulation of the position of each hydraulic cylinder 4, 5 is in each case by the feedback of a linear sensor

(not shown), by the positioning of a piston rod 43, 53 of each cylinder 4, 5 by one of the digital valve controller 1 to be adjusted

Hydraulic pressure can be controlled exactly.

The shut-off valves 15, 16, 17, 18 shown in FIG. 1 are hydraulic digital valves which are actuated by a digital control valve 19 operated by an electromagnet 191. A hydraulic fluid pressure, the

Control of the shut-off valves 15, 16, 17, 18 is also supplied by the pump 2 via the input line of the digital valve module 11. The common connection of the control valve 19 with each of the shut-off valves 15, 16, 17, 18 enables all shut-off valves 15, 16, 17, 18 to be simultaneously and thereby power-saving controlled to be either open or closed. With such a control arrangement, it is also conceivable to control more than four shut-off valves simultaneously and energy-saving.

The normally closed (NC) digital valves of the

Digital valve controller 1 have the same structure as the control valve 19, which is urged in the unactuated, ie in the de-energized state by a spring element 192 in a closed position. After a desired

Applying hydraulic pressure to the hydraulic cylinders 4, 5, a position of the piston rods 43, 53 achieved thereby in each hydraulic cylinder 4, 5 can be maintained. by the shut-off valves 15, 16, 17, 18 are closed. During a closed state of

Shut-off valves 15, 16, 17, 18 may also perform various diagnostic and maintenance procedures of the digital valve modules 11, 12, 13, 14 to verify that all of the digital valves of the digital valve controller 1 are functioning properly. Such a diagnostic and

Maintenance procedure is already in former place

described.

In this case, a hydraulic fluid supply to the

Abschaltventilen 15, 16, 17, 18 interrupted, resulting in that the shut-off valves 15, 16, 17, 18 acting hydraulic fluid through a drain (not shown) can be discharged and the shut-off valves 15, 16, 17, 18 by a each provided spring element 151, 161, 171, 181 are urged into an open position. In this way, a hydraulic pressure acting on the hydraulic cylinders 4, 5 can be reduced via the open shut-off valves 15, 16, 17, 18 and the safety valve 112, 122, 132, 142 provided in each digital valve module 12, 13, 14, 15. This prevents that the hydraulic cylinders 4, 5 are detected or locked in a fixed position. The positioned by the hydraulic cylinders 4, 5 rollers can therefore by hand or by a

Security system (not shown) are moved to a starting position, for example, to free a running over the rollers paper, board or tissue web in a paper, board or tissue machine.

In Fig. 2, another arrangement according to the invention is shown, in which a digital valve controller 1 two

Digital valve modules 11, 12, whose structure with those of the digital valve modules 11, 12 of FIG. 1 matches. Each digital valve module 11, 12 is thus as in the in Fig. 1 shown arrangement of twelve digital valves, wherein the common input line of each

Digital valve module 11, 12 is connected to six normally closed (NC) input digital valves. The six normally closed (NC) input digital valves open into a common supply line 111, 121, which in turn is connected to five normally closed (NC) output digital valves and a normally open (NO) output digital valve 112, 122, the output -Digital valves in the common output line of each digital valve module

II, 12 lead. The normally open (NO) output digital valve 112, 122 of each digital valve module 11, 12 serves as a safety valve 112, 122 in the event of a power failure, malfunction or the like

Draining the fluid to be controlled allows.

The supply lines 111, 121 are each over a

Control unit 7 with a hydraulic chamber 41, 42, 51, 52 of a hydraulic cylinder 4, 5, wherein the

Control unit 7 consists of a normally open (NO) digital valve 71 and a normally closed (NC) digital valve 72. Between both digital valve modules 11, 12 a normally closed (NC) digital valve 6 is provided, which serves as a connecting valve 6 and the supply lines

III, 121 can optionally connect to each other.

In a closed state of the connecting valve 6, the supply line 111 of the digital valve module 11 via the corresponding control unit 7 with the rod side

Hydraulic chamber 42 of the hydraulic cylinder 4 and / or the rod-side hydraulic chamber 52 of the hydraulic cylinder 5 is connected, and the supply line 121 of

Digital valve module 12 is above the corresponding

Control unit 7 with the piston-side hydraulic chamber 41st the hydraulic cylinder 4 and / or the piston side

Hydraulic chamber 51 of the hydraulic cylinder 5 is connected.

In an open state of the communication valve 6 and a closed state of all the digital valves of the regulator 1, the supply line 111 is short-circuited to the supply line 121, so that the rod-side hydraulic chamber 41 of the hydraulic cylinder 4 and / or the rod-side hydraulic chamber 51 of the hydraulic cylinder 5 directly to the piston-side hydraulic chamber 42 of the hydraulic cylinder 4 and / or the piston-side hydraulic chamber 52 of the

Hydraulic cylinder 5 is connected, whereby a direct hydraulic pressure exchange between the chambers 41, 42, 51, 52 can be caused. The normally open (NO)

Digital valve 72 of each control unit 7 serves as a safety valve similar to the safety valve 112, 122 in each digital valve module 11, 12, to a

Allow venting in case of power failure, malfunction or the like. As required, both digital valves 71, 72 of each control unit 7 can be open

be switched, whereby a larger fluid flow to the corresponding hydraulic chamber 41, 42, 51, 52nd

is possible. As a result, a fast control of a hydraulic chamber 41, 42, 51, 52 can be achieved.

Between each control unit 7 and each hydraulic chamber 41, 42, 51, 52 and between the pump 2 and the

Fluid reservoir 3 and the digital valve controller 1, a pressure sensor or a flow sensor 8 is provided in each case to measure a hydraulic pressure or a hydraulic fluid flow and to enable a hydraulic pressure control.

In the nip pressure setting operation, the desired pressures in each hydraulic chamber 41, 42, 51, 52 are adjusted, and the digital valves 71, 72 of FIG Control units 7 closed, which corresponds to a pressure fluid saving mode. When the pressure measuring sensors 8 provided between the control units 7 and the hydraulic chambers 41, 42, 51, 52 indicate a pressure loss, one or both of the digital valves 71, 72 of the corresponding ones will be detected

Control unit 7 is opened to make a pressure correction to the setpoint. It can be based on the

Connecting valve 6, the two digital valve modules 11, 12 are connected to each other, so that the digital valve regulator 1, depending on the requirement, may be able to pressurize the corresponding one of the hydraulic pressure chambers 41, 42, 51, 52 with the desired hydraulic pressure. By an arrangement, as shown in Fig. 2, it is in

Compared to the arrangement in Fig. 1 possible, two

Hydraulic cylinder with only two digital valve modules and thus with a total of thirty three digital valves

instead of two digital valve modules per

Hydraulic cylinder (ie a total of four digital valve modules) to provide.

A normally open safety valve

Digital valve is also conceivable in other applications. For example, such a safety valve is in a squeegee device for coating a fibrous web, such as e.g. a paper, board or tissue web in the

digital printing system for adjusting the pressure of the

Doctor blade on the fiber web conceivable to allow removal of the doctor bar from the fiber web in case of power failure or malfunction of the doctor device. It is also possible to provide such a safety valve in a digital lubrication circuit system, so that a residual lubrication is ensured in a fault.

Apart from their use in a fiber web machine are other other uses for the previously described arrangements conceivable. For example, such regulator assemblies can be used in any pressure and / or flow control of a

fluid pressure driven system or actuator can be used.

Claims

PATENTA'S TEST

1. An arrangement for controlling the position of a roller or the nip pressure of a formed between two rollers

Roll nips, in particular in a paper, board or tissue machine, with:

at least one fluid pressure driven actuator (4, 5) for changing the roller position or the

Wal censpalt,

at least one associated with the at least one actuator (4, 5) or with a plurality of fluid pressure actuated actuators (4, 5) digital valve controller (1) having a plurality of digital valves and which is capable of Aktuatorfluiddruck and / or Aktuatorfluiddurchfluss to control, and

at least one first digital, normally open shut-off valve (15, 16, 17, 18, 71) provided between the regulator (1) and the actuator (4, 5), respectively.

2. Arrangement according to claim 1, wherein

the actuator (4, 5) is a hydraulic cylinder (4, 5); the controller (1) has at least two digital valve modules (11, 12); and

a digital valve module (11) having a rod-side hydraulic chamber (41, 51) and the other digital valve module (12) with a piston-side hydraulic chamber (42, 52) is connected to control a translational displacement movement of the hydraulic cylinder (4, 5).

An arrangement according to claim 2, wherein the first digital normally-open shut-off valve (15, 16, 17, 18, 71) is provided between each digital valve module (11, 12) and the associated hydraulic chamber (41, 41, 51, 52) ,

4. Arrangement according to one of claims 2 and 3, wherein the arrangement further comprises at least a second digital shut-off valve (72), each parallel to the first digital shut-off valve (71) between the controller

(1) and the at least one fluid pressure driven actuator

(4, 5) is provided.

5. Arrangement according to claim 4, wherein in each case a first digital shut-off valve (71) and a second digital shut-off valve (72) form a control unit (7), each between a digital valve module (11, 12) and a hydraulic chamber (41, 42, 51 , 52) as the

at least one actuator acting hydraulic cylinder (4, 5) is provided.

6. Arrangement according to claim 4 or 5, wherein the second digital shut-off valve (72) is a normally closed

Digital valve (72) is.

7. Arrangement according to one of claims 2 to 6, wherein a normally closed, digital connection valve (6) between the two digital valve modules (11, 12) of the

Regulator (1) is provided.

8. Arrangement according to one of the preceding claims, wherein the at least one first digital shut-off valve (15, 16, 17, 18) is a hydraulically controlled digital valve (15, 16, 17, 18).

9. Arrangement according to claim 8, wherein the hydraulic supply of the at least one first digital shut-off valve (15, 16, 17, 18) by a control valve (19) is controlled.

10. Arrangement according to claim 9, wherein the control valve (19) is an electromagnetically actuated, normally closed digital valve (19).

11. Arrangement according to one of the preceding claims, wherein a pressure sensor (8) and / or a flow sensor (8) in each case between the at least one first shut-off valve (71) and the at least one actuator (4, 5) is arranged.

12. Arrangement according to one of the preceding claims, wherein the controller (1) has at least one normally open digital valve (112, 122, 132, 142).

13. Arrangement according to one of claims 2 to 12, wherein each digital valve module (11, 12, 13, 14) at least one normally open digital valve (112, 122, 132, 142).

14. Arrangement according to one of claims 2 to 13, wherein a digital valve module (11, 12, 13, 14) of a plurality

Digital valves exists.

15. Control method for an arrangement for controlling the position of a roll or the nip pressure of a nip formed between two rolls, in particular in a paper, board or tissue machine, with the

following steps:

Opening a certain number of digital valves of a digital valve module (11, 12) of a digital valve controller (1),

Opening at least one first digital

Shut-off valve (15, 16, 71), which between the one

Digital valve module (11, 12) and one to be controlled

Hydraulic chamber (41, 42) of a first hydraulic cylinder (4) is provided; Supplying hydraulic fluid to the hydraulic chamber (41, 42) to be controlled until a desired one

Hydraulic pressure in the hydraulic chamber (41, 42) is reached; and

Closing the shut-off valve (15, 16, 71).

16. The method of claim 15, wherein

another hydraulic cylinder (5) is connected in parallel with the first hydraulic cylinder (4) to the controller (1);

the step of opening at least a first one

Shut-off valve (15, 16; 71) comprises opening of a further first digital shut-off valve (15, 16, 71) which is connected between the one digital valve module (11, 12) and a parallel-connected hydraulic chamber (51, 52) of the further hydraulic cylinder (5). is arranged;

the step of supplying hydraulic fluid to the hydraulic chamber (41, 42) to be controlled supplies hydraulic fluid to the parallel connected one

Hydraulic chamber (51, 52) comprises; and

the step of closing the shut-off valve comprises closing all shut-off valves (15, 16, 71, 72).

17. Control method for an arrangement for controlling the position of a roll or the nip pressure of a nip formed between two rolls, in particular in a paper, board or tissue machine, with the

following steps:

Close all digital valves of two

Digital valve modules (11, 12) of a digital valve controller (1),

Opening a digital connection valve (6), the one line between a digital valve module (11) of the two digital valve modules (11, 12) and a

Hydraulic chamber (41) of a first hydraulic cylinder (4) communicating with a line between the other digital valve module (12) of the two digital valve modules (11, 12) and the other hydraulic chamber (42) of the hydraulic cylinder (4); and

Opening at least one first digital

Shut-off valve (71), each between the one

Digital valve module (11) and the one hydraulic chamber (41) and between the other digital valve module (12) and the other hydraulic chamber (42) is provided to selectively transfer a hydraulic fluid between the hydraulic chambers (41, 42) of the hydraulic cylinder (4).

18. The method of claim 17, wherein

another hydraulic cylinder (5) is connected in parallel with the first hydraulic cylinder (4) to the controller (1); and

the step of opening at least one first digital cutoff valve (71) comprises opening at least one further first digital cutoff valve (71) between each of the one digital valve module (11) and the one hydraulic chamber (51) of the further hydraulic cylinder (5) and between the one another digital valve module (12) and the other hydraulic chamber (52) is provided for selectively transferring a hydraulic fluid between the hydraulic chambers (41, 42, 51, 52) of the hydraulic cylinders (4, 5).

19. The method of claim 15, wherein a second digital shut-off valve is arranged in parallel with the first digital shut-off valve, and wherein the step of opening at least one digital shut-off valve is opening the first digital shut-off valve

Shut-off valve (71) and the second digital

Shut-off valve (72).

A method according to any of claims 15 to 19, wherein the first digital shut-off valve (15, 16, 17, 18, 71) is a normally open digital valve.

21. The method according to any one of claims 15 to 20, wherein the second digital shut-off valve (72) normal

closed shut-off valve is.

22. A diagnostic and maintenance method for an arrangement for controlling the position of a roll or the nip pressure of a nip formed between two rolls, in particular in a paper, board or tissue machine, comprising the following steps:

Closing at least one digital shut-off valve (15, 16, 17, 18) which is connected between a digital valve module (11, 12, 13, 14) of a digital valve regulator (1) and a hydraulic chamber (41, 42, 51, 52) to be triggered Hydraulic cylinder (4, 5) is provided;

Open all digital valves at least one

Digital valve module (11, 12, 13, 14) of the digital valve controller (1) according to a specific switching sequence and

Supplying the regulator (1) with hydraulic fluid; and

Determining a faulty digital valve based on the hydraulic fluid flow rate exiting the regulator (1) and / or the hydraulic fluid pressure.

23. The method of claim 22, wherein the shut-off valve (15, 16, 17, 18) is a hydraulically controlled digital valve (15, 16, 17, 18).

24. The method of claim 23, wherein the hydraulic supply of the shut-off valve (15, 16, 17, 18) is controlled by a control valve (19).

25. The method of claim 24, wherein the control valve (19) is an electromagnetically actuated, normally closed digital valve (19).

26. The method of claim 22, wherein the step of closing the at least one shut-off valve is controlled by the control valve.