DE102012216708B4 - Method for operating a brush system on a rolling stand and brushing system - Google Patents

Abstract

Method for operating a brush installation (1) on a roll stand (2), wherein the brush installation (1) comprises at least one rotating brush (3) which can be brought into engagement with a work roll (4) of the roll stand (2), wherein the brush (3) is rotationally driven by a hydraulic motor (5), the hydraulic motor (5) being connectable to a pressurized fluid supply source (6), the pressurized fluid supply source (6) comprising a pump (7) and a drive motor (7) driving the pump (7). 8) and wherein a working fluid is maintained at a predetermined base pressure (p0) by the pump (7), characterized in that the method comprises the steps of: a) detecting the force applied to the work roll (4) by the brush (3) Load and / or the power consumed by the brush (3) (PB); b) determining a working pressure (p1) of the working fluid required for application of the load or application of the power (PB) of the brush (3); c) comparing the required working pressure (p1) with the base pressure (p0); d) Reduction of the drive power (PM) of the drive motor (8) of the pressure fluid supply source (6), when the working pressure (p1), taking into account a tolerance, is lower than the base pressure (p0) and increase the drive power (PM) of the drive motor (8) the pressurized fluid supply source (6) when the working pressure (p1), considering a tolerance, is higher than the base pressure (p0).

Description

The invention relates to a method for operating a brush system on a roll stand, wherein the brush system comprises at least one rotating brush which is engageable with a work roll of the rolling stand, wherein the brush is rotatably driven by a hydraulic motor, wherein the hydraulic motor in communication with a pressure fluid supply source can be brought, wherein the pressure fluid supply source comprises a pump and a drive motor driving the pump and wherein a working fluid is held by the pump at a predetermined base pressure. Furthermore, the invention relates to a brush system.

In particular, when rolling aluminum alloys, a periodic cleaning of the roll surfaces of the work rolls is necessary. In the hot rolling area, this applies both to the roughing of the roughing mill and to the scaffolding of the finishing train. For this purpose, generic brush systems are known. These have cylindrical brushes on the rolling stands parallel to each work roll.

The brushes can be pivoted on or off by means of hydraulic cylinders, d. H. the brushes are pivoted when needed to the roller. In order to achieve a sufficient cleaning effect, the brushes designed as rotary brushes are driven by hydraulic motors. The variation in the speed of the brushes results in adjustable relative movement between the work roll surface and the cleaning bristles of the brush.

The interaction of a rotary brush with a work roll is for example from JP 6011 8464 A known.

The US 5,531,090 A discloses a brushing system and method for operating a brushing system on a rolling stand, wherein the brushing device comprises at least one rotating brush engageable with a work roll of the rolling mill, the brush being rotationally driven by a hydraulic motor.

The US 3,379,044 A discloses a brushing system and a method of operating a brushing system on a rolling stand, wherein the brushing device comprises at least one rotating brush which is engageable with a work roll of the rolling mill stand. Further, US 3,379,044 A discloses a control for the hydraulic movement of the brush relative to the work roll.

DE 10 2006 036 710 A1 discloses a brushing system and a method of operating a brushing system on a rolling stand, wherein the brushing device comprises at least one rotating brush engageable with a work roll of the rolling stand. Furthermore, DE 10 2006 036 710 A1 discloses a force control for regulating the contact force of the brush.

The EP 0107514 A2 discloses a brushing system and a method of operating a brushing system on a rolling stand, wherein the brushing device comprises at least one rotating brush engageable with a work roll of the rolling stand. Furthermore, the brush is driven by means of a hydraulic motor and the adjusting force adjusted by means of an air cylinder variable.

The requirements for a sufficient cleaning effect lead to high-performance hydraulic motors with high performance, which causes high system pressures of the working fluid (oil) at high flow rates. The source of pressurized fluid must provide a sufficiently high fluid pressure for this. In order to be able to drive a predetermined speed and torque profile when the brush is driven, in this case by means of the pressure fluid supply source such a large fluid pressure is provided which is sufficient during all operating states of the brush system. This results from the larger engines a significant heat input into the system and in consequence a high power loss, which must be dissipated by correspondingly large-sized radiator. The energy requirement is correspondingly high.

The system pressure required for the operation of the brush drive hydraulic motors is therefore provided at a constant level by the pressure fluid supply source. A disadvantage of this solution that - caused by the pressure difference between inlet and outlet side of the drive - large losses in the idling of the brushes. As the system pressure increases, these losses increase considerably.

The invention has for its object to provide a method of the type mentioned above and a corresponding brush system, so that even large hydraulic motors for the brush drive are sufficiently supplied with working fluid that, however, reduced in comparison with the previously known solution, the heat input into the system and the rest also the energy requirement can be reduced.

• a) Erfassen der von der Bürste auf die Arbeitswalze aufgebrachte Last und/oder der von der Bürste aufgewendeten Leistung;
• b) Bestimmung eines für die Aufbringung der Last oder Aufwendung der Leistung der Bürste erforderlichen Arbeitsdrucks des Arbeitsfluids;
• c) Vergleichen des erforderlichen Arbeitsdrucks mit dem Basisdruck;
• d) Reduzierung der Antriebsleistung des Antriebsmotors der Druckfluidversorgungsquelle, wenn der Arbeitsdruck, unter Berücksichtigung einer Toleranz, geringer ist als der Basisdruck und Erhöhung der Antriebsleistung des Antriebsmotors der Druckfluidversorgungsquelle, wenn der Arbeitsdruck, unter Berücksichtigung einer Toleranz, höher ist als der Basisdruck.

The solution of this object by the invention is according to the method characterized in that the method comprises the steps:

• a) detecting the load applied by the brush to the work roll and / or the power consumed by the brush;
• b) determining a working pressure of the working fluid required to apply the load or to apply the power of the brush;
• c) comparing the required working pressure with the base pressure;
• d) Reduction of the drive power of the drive motor of the pressure fluid supply source, when the working pressure, taking into account a tolerance, is lower than the base pressure and increase the driving power of the drive motor of the pressure fluid supply source when the working pressure, taking into account a tolerance, is higher than the base pressure.

The said steps a) to d) are carried out continuously in the sense of a regulation in order to keep the base pressure at the desired level. Accordingly, steps a) to d) are repeated after step d) is reached. If the base pressure is at the level of the working pressure, d. H. If the comparison according to step c) results in a difference of zero, no corresponding effect is made on the working power of the drive motor.

According to training, a minimum pressure can be specified, which is maintained in any case behind the pump.

In the above step a), a pressing force of the brush against the work roll can be detected. It is also possible that in this step, the drive power is detected, with which the brush is driven. Furthermore, here also the torque can be detected, with which the brush is driven by the hydraulic motor.

The method is preferably used in roll rolling of aluminum or aluminum alloys.

According to the invention, the proposed generic brush arrangement provides means by which the load applied by the brush to the work roll and / or the power consumed by the brush can be measured, as well as a control device with which the base pressure is measured as a function of the measured load and / or Performance can be regulated.

The means may be designed to measure a pressing force of the brush against the work roll. They can also be designed to measure the drive power of the brush.

According to the invention, it is thus provided that the hydraulic brush drives are supplied with a system pressure (base pressure) provided by the pressure fluid supply source, which is adapted to the load pressure (working pressure) of the hydraulic motor. This adaptation takes place in a closed loop. For this purpose, a measurement of the load ("load sensing"), under which the hydraulic motor is.

In the relatively long periods in which the brushes are not active, the system pressure (base pressure) in the pressure fluid supply source is thus purposefully reduced according to the invention. The losses of the hydraulic motors are thus reduced by the pressure level (the base pressure) in the time in which the brushes are passive, is lowered. This is controlled by measuring the load applied to the brush.

The separate system pressure for the brush drives offers the possibility of compensating for a possible reduction in dynamics - due to the temporary reduction in pressure - by integrating an additional valve. This load-sensing valve is incorporated into the existing pressurized fluid supply. This valve is preferably mounted over a magnet and therefore can be easily positioned.

The control of the valve is linked to the engine speed control and the cleaning demand control for optimum results.

The hydraulic power density of the system can thus be increased flexibly, while maintaining the small size of the drives and ancillaries.

Another positive effect is that a roll change can be simplified due to the retained small space.

So far, a constant high pressure level was always maintained in the pressure fluid supply source, although the high system pressure usually only for relatively short times - namely for the cleaning of the roller - must be present.

Advantageously, this considerably less energy for the brush system is required. Furthermore, the heat loss is significantly reduced. This makes it possible to use smaller heat exchangers (radiators).

It is sufficient for the present application, an initially low base pressure, which is raised only when a load on the brush.

Preferably, the method and the brush system described are used in the rolling of aluminum alloys.

In the drawings, an embodiment of the invention is shown. Show it:

1 schematically a brush system with which the work roll of a roll stand can be cleaned according to an embodiment of the invention, and

2 a schematic representation of the control concept of a control device according to the invention.

In 1 is a brush attachment 1 seen at a rolling mill 2 is arranged. The brush system 1 has at least one brush 3 on, which is designed as a rotary brush and by a hydraulic motor 5 is driven. If necessary, the brush will 3 to a work roll 4 of the rolling stand 2 moved up or pivoted up.

The hydraulic motor 5 for the rotary drive of the brush 3 is from a pressurized fluid supply source 6 supplied with pressurized fluid with a defined base pressure p0. This is provided by the pressurized fluid supply source 6 via a drive motor 8th that a pump 7 drives, so as to provide the required base pressure p0 at a required flow rate available. Usual or typically required further elements (fluid) are not shown or indicated only schematically.

In order to be able to work in an energy-efficient manner and with low energy input into the system, the following procedure is provided:
The on the stripper 4 applied load or that of the brush 3 spent power PB is first detected, including measuring means 12 available. The power detection can be done in a simple way by product formation of the between hydraulic motor 5 and brush 3 acting torque and the angular velocity of the brush (ie, ultimately the speed of the brush) done.

A determination is made of one for applying the load or applying the power PB of the brush 3 required working pressure p1 of the working fluid by means of the measuring means 15 and the base pressure p0 by means of the measuring means 16 , The measured pressures p1 and p0 are sent to the controller 14 transmitted.

The torque M of the brushes is in this case a function of the pressures p1 and p0, ultimately of their difference Δp, whereas the rotational speed n is a function of the power PB. The power PB is in the illustrated device by means of the measuring means 12 certainly.

The hydraulic power is the product of pressure and volume flow of the working fluid. Thus, for example, the volume flow of the hydraulic oil through the hydraulic motor 5 detected with a flow meter, the working pressure p1 can be easily determined when the drive power of the brush (see above).

At the output of the pressure supply source 6 is a pressure transmitter 13 present, with which the base pressure p0 of the pressure supply source 6 is determined.

Both the specific value of the working pressure p1 and the measured base pressure p0 become a subtractor 11 fed, ie it is a comparison of the required working pressure p1 with the base pressure p0.

The determined difference is from the subtractor 11 a control device 9 fed to the drive motor 8th so that the said difference is minimal. Accordingly, the base pressure p0 is made equal to the actually required working pressure p1.

Thus, there is a reduction in the drive power PM of the drive motor 8th the pressure fluid supply source 6 when the working pressure p1 is less than the base pressure p0; However, there is an increase in the drive power PM of the drive motor 8th the pressure fluid supply source 6 when the working pressure p1 is higher than the base pressure p0.

With this control, a tolerance can be taken into account, which is given according to the regulation. Accordingly, an influencing of the drive motor takes place only then 8th if the amount of the specific difference of the subtractor 11 exceeds a predetermined value.

Accordingly, the drive power PM of the drive motor 8th adjusted to a lower level, which reduces energy consumption and reduces the energy input into the system. Accordingly, it is possible to work with smaller cooling systems.

The inventively provided way to reduce the losses during idling of the hydraulic motor, is to lower the pressure level of the pressure oil supply, ie the base pressure at idle the brush. As a result, the system pressure is variably adjusted for the first time at the usual variable working pressure and no longer maintained at a high level. Provided is the thermal losses of the hydraulic motors 5 by reducing the pressure of the pressure oil supply (base pressure) p0 dynamically to the current load pressure (working pressure) p1.

For several consumers (hydraulic motors 5 ) connected to the pressurized fluid supply source 6 are connected, the highest load pressure p1 is dominant for setting the current system pressure (base pressure) p0. This is acted upon by an offset value Δp and is the manipulated variable for the pressure regulator of the pump 7 , To a beating between the speed controller of the hydraulic motor 5 and the pressure regulator of the pump 7 To avoid this, a hysteresis must be taken into account when calculating the switchover point.

In 2 is schematically the control concept of the control device 9 outlined. Far left is the subtractor 11 in which the difference between the working pressure p1 (pIN) and the base pressure p0 (pOUT) is determined. In the control device 9 the difference is added an offset value Δp (pOFS) (s. 2 ). Accordingly, the switching on or off of the drive motor 8th (SON / SOFF) to finally reach the desired base pressure p0 (pSOLL).

Overall, such a reduction of the thermal losses of more than 30%, preferably more than 50%, more preferably more than 60%, can be achieved.

LIST OF REFERENCE NUMBERS

1

brush equipment

2

rolling mill

3

brush

4

Stripper

5

hydraulic motor

6

Pressure fluid supply source

7

pump

8th

drive motor

9

control device

10

converter

11

differentiator

12

measuring Equipment

13

thruster

14

control

15

Measuring equipment (p1)

16

Measuring equipment (p0)

p0

base pressure

p1

working pressure

PB

power

PM

Drive power of the drive motor

Claims (10)

Method for operating a brush system ( 1 ) on a rolling stand ( 2 ), whereby the brush system ( 1 ) at least one rotating brush ( 3 ) provided with a work roll ( 4 ) of the roll stand ( 2 ) is engageable, wherein the brush ( 3 ) of a hydraulic motor ( 5 ) is rotationally driven, wherein the hydraulic motor ( 5 ) with a pressurized fluid supply source ( 6 ), the pressure fluid supply source ( 6 ) a pump ( 7 ) and one the pump ( 7 ) driving drive motor ( 8th ) and wherein a working fluid through the pump ( 7 ) (At a predetermined base pressure p0) is held, characterized in that the method comprises the steps of: a) detecting (of the brush 3 ) on the work roll ( 4 ) applied load and / or the brush ( 3 ) spent power (PB); b) Determining one for the application of the load or application of the power (PB) of the brush ( 3 ) required working pressure (p1) of the working fluid; c) comparing the required working pressure (p1) with the base pressure (p0); d) Reduction of the drive power (PM) of the drive motor ( 8th ) of the pressurized fluid supply source ( 6 ), when the working pressure (p1), taking into account a tolerance, is lower than the base pressure (p0) and increasing the drive power (PM) of the drive motor ( 8th ) of the pressurized fluid supply source ( 6 ) when the working pressure (p1), taking into account a tolerance, is higher than the base pressure (p0). A method according to claim 1, characterized in that a minimum pressure is predetermined, which in any case behind the pump ( 7 ) is maintained. A method according to claim 1 or 2, characterized in that in step a) of claim 1, a pressing force of the brush ( 3 ) against the work roll ( 4 ) is detected. A method according to claim 1 or 2, characterized in that in step a) of claim 1, the drive power (PB) is detected, with which the brush ( 3 ) is driven. A method according to claim 1 or 2, characterized in that in step a) of claim 1, the torque is detected, with which the brush ( 3 ) from the hydraulic motor ( 5 ) is driven. Method according to one of claims 1 to 5, characterized in that it is used during hot rolling of aluminum or aluminum alloys. Brushing plant ( 1 ) on a rolling stand ( 2 ), whereby the brush system ( 1 ) at least one rotating brush ( 3 ) provided with a work roll ( 4 ) of the roll stand ( 2 ) is engageable, wherein the brush ( 3 ) of a hydraulic motor ( 5 ) is rotationally driven, wherein the hydraulic motor ( 5 ) with a pressurized fluid supply source ( 6 ), the pressure fluid supply source ( 6 ) a pump ( 7 ) and one the pump ( 7 ) driving drive motor ( 8th ), wherein the pump ( 7 ) can hold a pressure fluid at a predetermined base pressure (p0), in particular for carrying out the method according to one of claims 1 to 6, characterized in that means ( 12 ) are present, with which of the brush ( 3 ) on the work roll ( 4 ) applied load and / or the brush ( 3 ) (PB) and a control device ( 9 ), with which the base pressure (p0) can be regulated as a function of the measured load and / or power (PB). Brushing installation according to claim 7, characterized in that the means ( 12 ) for measuring a pressing force of the brush ( 3 ) against the work roll ( 4 ) are formed. Brushing installation according to claim 7, characterized in that the means ( 12 ) are designed for measuring the drive power (PB) of the brush. Brushing installation according to one of claims 7 to 9, characterized in that it is part of an aluminum hot rolling mill.

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