EP2099574B1 - Control method for a rolling stand for rolling a strip - Google Patents

Abstract

A strip has a left and a right side. The strip is rolled in a rolling stand. Stresses occurring in the strip at the feed and exit sides are detected by corresponding measuring sensors positioned on the left and right sides of the strip. The detected stresses are fed to a control unit for the rolling stand. The control unit determines a measurement for the transversal positioning of the strip in relation to the rolling stand using the relationship Z=ZLE*ZLA−ZRE−ZRA, where Z is the measurement. ZLE, ZLA, ZRE and ZRA are the individually detected stresses. The control unit determines a correcting variable for correcting the transversal positioning of the strip using the measurement for the transversal positioning and controls the rolling stand according to the correcting variable.

Description

The present invention relates to a control method for a rolling stand for rolling a belt having left and right belt sides.

Such control methods are well known.

When rolling tapes, it can happen that the rolled strip - relative to the strip running direction - migrates laterally. The emigration of the tape usually has the consequence that the tape is seen unevenly rolled in the transverse direction of the tape. The uneven rolling can lead to difficulties in subsequent processing stages (especially in downstream rolling stands). As a rule, it is therefore attempted to roll the strip in such a way that, viewed in the transverse direction of the strip, the center line of the roll stand and the center line of the strip coincide (middle layer).

From the JP 07 124 620 A It is known to detect by means of suitable transducers on the left and right side of the belt on the inlet and outlet sides of each there prevailing train and on the inlet and outlet side to form the difference of each detected trains. The differences of the trains are fed to a control device which determines a manipulated variable for a displacement of the belt on the basis of the differences. The manipulated variable is output to an actuator, by means of which the transverse positioning is corrected in the direction of the central position.

From the DE 10 2004 043 790 A1 For example, a control method for a rolling stand for rolling a strip is known, wherein the strip has a left and a right side of the strip. In this control method, pressures are detected by means of corresponding transducers, which exerts the tape on the inlet and outlet side in the lateral direction of the tape on the measured value. The Measured values are fed to a control device for the roll stand which relates the measured values to one another and in this way determines a manipulated variable for the roll stand by means of which a saber formation of the strip leaving the roll stand is counteracted.

The procedure of the prior art is functional. However, it is still possible to improve.

The object of the present invention is to provide objects by means of which the transverse positioning of the band can be determined in a simple manner is. The object is procedurally achieved by a control method for a rolling mill with the features of claim 1. Programmtechnisch the problem is solved by a computer program with the features of claim 2. In terms of equipment, the object is achieved by a data carrier having the features of claim 3, a control device having the features of claim 4 and a rolling device having the features of claim 5.

ein Maß für eine Querpositionierung des Bandes relativ zum Walzgerüst. ZLE ist hierbei der an der linken Wandseite einlaufseitig im Band herrschende Zug, ZLA ist der an der linken Bandseite auslaufseitig im Band herrschende Zug, ZRE ist der an der rechten Bandseite einlaufseitig im Band herrschende Zug und ZRA ist der an der rechten Bandseite auslaufseitig im Band herrschende Zug. δZ ist das Maß. Anhand des Maßes für die Querpositionierung des Bandes ermittelt die Steuereinrichtung eine Stellgröße für eine Korrektur der Querpositionierung des Bandes. Sie steuert das Walzgerüst entsprechend der Stellgröße an.According to the invention by means of corresponding transducers on the left and the right side of the band on the inlet and outlet sides prevailing in the band trains detected. The detected trains are fed to a controller for the rolling stand. The controller determines based on the relationship $$\mathrm{Az}\mathrm{=}\mathrm{ZLE}\mathrm{+}\mathrm{ZLA}\mathrm{-}\mathrm{ZRE}\mathrm{-}\mathrm{ZRA}$$

a measure of a transverse positioning of the strip relative to the roll stand. ZLE is here the train prevailing on the left side of the wall in the belt, ZLA is the train running out of the belt on the left side of the belt, ZRE is the train running on the right side of the belt and ZRA is the belt on the right side ruling train. ΔZ is the measure. On the basis of the measure for the transverse positioning of the belt, the control device determines a manipulated variable for a correction of the transverse positioning of the belt. It controls the rolling stand according to the manipulated variable.

The computer program includes a sequence of
Machine commands, wherein the sequence of machine commands is executable by the controller. The execution of the sequence of machine commands by the controller causes the controller to control the mill according to the method described above when the controller is operatively connected to the mill stand. On the disk and in the control device such a computer program is stored in each case.

• FIG 1 schematisch eine Walzeinrichtung und ein Band von oben,
• FIG 2 schematisch die Walzeinrichtung und das Band von FIG 1 von der Seite,
• FIG 3 schematisch die Walzeinrichtung und das Band von FIG 1 von vorne und
• FIG 4 schematisch eine mögliche Art der Ermittlung einer Stellgröße.

Further advantages and details emerge from the following description of an embodiment in conjunction with the drawings. In a schematic representation:

• FIG. 1 schematically a rolling device and a belt from above,
• FIG. 2 schematically the rolling device and the belt of FIG. 1 of the page,
• FIG. 3 schematically the rolling device and the belt of FIG. 1 from the front and
• FIG. 4 schematically a possible way of determining a manipulated variable.

According to the 1 to 3 For example, a rolling device has a rolling stand 1 and a control device 2 for the rolling stand 1. By means of the roll stand 1, a strip 3 is rolled in operation, which has a left hinge side 3 'and a right hinge side 3 ".

The rolling mill 1 has at least two work rolls 4. As a rule, the roll stand 1 has further rolls, for example when formed as a quill screed support rolls or when forming a sexto scaffolding support and intermediate rolls. Other configurations, for example as a so-called Zwanzig roll rolling stand, are possible. The other rollers are not shown in the FIG.

The control device 2 controls the entire operation of the rolling mill 1. For example, it controls the peripheral speed of the work rolls 4, the setting of the rolling stand 1, the rolling force, etc. On the control of the Roll stand 1 by the control device 2 will be discussed below only to the extent necessary for the understanding of the present invention.

The control device 2 is generally designed as a programmable control device, for example as a programmable logic controller (PLC). The operation of the control device 2 is therefore determined by a computer program 5, with which the control device 2 is programmed.

For programming the control device 2, the computer program 5 is created. It comprises a sequence of machine commands 6. The sequence of machine commands 6 can be executed by the control device 2. The execution of the sequence of machine commands 6 by the control device 2 causes the control device 2 to control the rolling stand 1 in accordance with a control method which will be explained in more detail below. Of course, the control device 2 must be in operative connection with the roll stand 1 for this purpose.

The computer program 5 is stored on a data carrier 7, for example an EEPROM. The data carrier 7 is - at least temporarily - connected to the control device 2 data technically. Thus, for example, it is possible that the control device 2, when executing its control method, always executes the computer program 5 stored on the data carrier 7. In this case, the data carrier 7 must be connected to the control device 2 during the execution of the control method. Alternatively, it is possible for the control device 2 to have its own internal memory (= internal data carrier), not shown in the FIG, in which it stores the computer program 5 after being read from the memory device in FIG FIG. 1 stored disk 7 stores. In this case, the data carrier 7 must be connected to the control device 2 only temporarily. Again alternatively, it is possible for the computer program 5 of the control device 2 via a not shown Supply network connection. In this case, only the internal volume of the controller 2 is required.

As part of the processing of the computer program 5, the control device 2 controls transducers 8, which are assigned to the rolling stand 1. By means of the transducers 8, trains ZLE, ZLA, ZRE, ZRA are detected, which prevail on the left and right side of the belt 3 ', 3 "on the infeed and outfeed sides in the belt 3. ZLE hereby designates the one on the left side of the belt 3' in the belt ZLA designates the tension prevailing on the left side of the belt 3 'in the belt 3. ZRE denotes the tension prevailing in the belt 3 on the belt side 3 "on the right side of the belt 3. ZRA designates the tension prevailing on the right side of the belt 3 "in the belt 3.

The specific configuration of the transducers 8 can be selected as needed. For example, the transducers 8 can be summarized on the inlet side on the one hand and on the outlet side on the other hand to a segmented traction measuring roller. Such tension measuring rollers are well known. However, other embodiments are conceivable and possible as an alternative.

The detected trains ZLE, ZLA, ZRE, ZRA are fed to the control device 2. The control device 2 determines based on the detected features ZLE, ZLA, ZRE, ZRA a measure δZ for a transverse positioning p of the belt 3 relative to the rolling stand 1. In particular - see FIG. 4 - The controller 2 determines the measure δZ based on the relationship $$\mathrm{Az}\mathrm{=}\mathrm{ZLE}\mathrm{+}\mathrm{ZLA}\mathrm{-}\mathrm{ZRE}\mathrm{-}\mathrm{ZRA}\mathrm{,}$$

On the basis of the measure δZ optionally in conjunction with a nominal dimension δZ * - the control device 2 determines a manipulated variable S. The manipulated variable S is output to the rolling stand 1. The rolling stand 1 is thus controlled according to the manipulated variable S.

The manipulated variable S causes a correction of the transverse positioning p of the belt 3. It can, for example - see schematically the arrows A in FIG. 3 - Be a wedge adjustment of the work rolls 4.

It is possible that the manipulated variable S depends continuously on the dimension ΔZ (or the difference of the dimension ΔZ from the nominal dimension ΔZ *). However, the manipulated variable S can also - like a two-position controller - have a hysteresis.

The above description is only for explanation of the present invention. The scope of the present invention, however, is intended to be determined solely by the appended claims.

Claims (5)

1. Control method for a rolling stand (1) for rolling a strip (3), which has a left side and a right side (3', 3"), characterized in that:

   - tensions (ZLE, ZLA, ZRE, ZRA) prevailing on the left and right sides (3', 3") of the strip (3) on the feed and exit sides are detected by means of appropriate measured-value transducers (8),

   - wherein the detected tensions (ZLE, ZLA, ZRE, ZRA) are fed to a control device (2) for the rolling stand (1),

   - the control device (2) determines on the basis of the relationship δZ = ZLE + ZLA - ZRE - ZRA a measure (δZ) of a transverse positioning (p) of the strip (3) in relation to the rolling stand (1),

   - δZ is the measure, ZLE is the tension prevailing on the left side (3') of the strip (3) on the feed side, ZLA is the tension prevailing on the left side (2') of the strip (3) on the exit side, ZRE is the tension prevailing on the right side (3") of the strip (3) on the feed side and ZRA is the tension prevailing on the right side (3'') of the strip (3) on the exit side,

   - the control device (2) determines on the basis of the measure (δZ) for the transverse positioning (p) of the strip (3) a correcting variable (S) for a correction of the transverse positioning (p) of the strip (3) and activates the rolling stand (1) in accordance with the correcting variable (S).
2. Computer program, which comprises a sequence of machine commands (6), wherein the sequence of machine commands (6) can be executed by a control device (2) for a rolling stand (1), wherein the execution of the sequence of machine commands (6) by the control device (2) has the effect that the control device (2) controls the rolling stand (1) in accordance with a method according to Claim 1 when the control device (2) is in operative connection with the rolling stand (1).
3. Data carrier with a computer program (5) according to Claim 2 stored on the data carrier.
4. Control device for a rolling stand (1), wherein the control device has a data carrier (7) according to Claim 3 and the computer program (5) stored on the data carrier (7) can be executed by the control device.
5. Rolling device with a rolling stand (1) controlled by a control device (2),

   - wherein a strip (3), which has a left side and a right side (3', 3"), can be rolled by means of the rolling stand (1), characterized in that:

   - the rolling stand (1) is assigned measured-value transducers (8), by means of which tensions (ZLE, ZLA, ZRE, ZRA) prevailing on the left and right sides (2', 3") of the strip (3) on the feed and exit sides can be detected,

   - wherein the detected tensions (ZLE, ZLA, ZRE, ZRA) can be fed to the control device (2),

   - a measure (δZ of a transverse positioning (p) of the strip (3) in relation to the rolling stand (1) can be determined by the control device (2) on the basis of the relationship δZ = ZLE + ZLA - ZRE - ZRA,

   - δZ is the measure, ZLE is the tension prevailing on the left side (3') of the strip (3) on the feed side, ZLA is the tension prevailing on the left side (3') of the strip (3) on the exit side, ZRE is the tension prevailing on the right side (3") of the strip (3) on the feed side and ZRA is the tension prevailing on the right side (3'') of the strip (3) on the exit side,

   - a correcting variable (S) for a correction of the transverse positioning (p) of the strip (3) can be determined by the control device (2) on the basis of the measure (δZ) for the transverse positioning (p) of the strip (3) and the rolling stand (1) can be activated by said control device in accordance with the correcting variable (S).

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