DE1264100B - Arrangement in strip rolling mills for measuring the distribution of strip tension across the strip width - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

GOIl

German class: 42 k -7/02

Number: 1264100

File number: A 48357IX b / 42 k

Filing date: February 9, 1965

Open date: March 21, 1968

The invention relates to an arrangement for measuring the tensile force with which a strip-shaped material is wound up by the take-up reel when it leaves the work rolls of a rolling mill.

To measure the force mentioned, an arrangement is usually used in which the tape in is bent at a known angle over a pulley, the bearings of which are on force-measuring arrangements, so-called tape tension knives are supported. When the deflection angle of the belt is constant is held, the output signal of the measuring arrangement provides information about the strip tension. the However, the arrangement does not provide any information about the distribution of the strip tension transversely to the rolling direction, but rather measures only the entire size of the train. Because the rolling stock and the rolls are uneven and If the temperature distribution in the strip is uneven, it can happen that the thickness decreases in a pair of work rolls unevenly and therefore also the extension and thus also the thickness of the band varies over the band width. This means that the tape is not level remains when the reel tape tension stops. Because the tape is rolled and rolled onto the reel is exposed to the tape tension, the unevenness of the tape only shows when the reel tape tension stops. So one does not have the possibility during the rolling of the one causing the unevenness Factors to act. If, on the other hand, you had the opportunity to do so while rolling continuously measuring the distribution of the tension in the strip transversely to the rolling direction, one would in in most cases can eliminate the cause of the unevenness. This could e.g. B. by local Cooling the rollers or the belt or done by other measures.

Devices are known with which the strip tension is measured at various points on the strip width will. However, these only allow an averaging of the strip tension. The known devices are intended for measuring the belt tension in paper webs. The one curved over The paper web, which is guided by a rail with holes, is subjected to dynamic pressure. The overall result Dynamic pressure should be proportional to the mean value of the paper pull.

It is also known for strip rolling mills to subject the strip to a constant pressure on one side and to draw conclusions about a non-linear stress distribution from the curvature of the strip or from the different curvature in the middle and on the sides of the strip. Such before arrangement in strip rolling mills for measuring the distribution of the strip tension over the
Bandwidth

Applicant:

Allmänna Svenska Elektriska Aktiebolaget,

Västeras (Sweden)

Representative:

Dipl.-Ing. H. Missling, patent attorney,
6300 Giessen, Bismarckstrasse. 43

Named as inventor:

Dr. Olivio Sivilotti, Kingston, Ontario (Canada)

Claimed priority:

Sweden of February 13, 1964 (1725),

dated September 21, 1964 (11291) - -

directions are complicated, unsafe as a result and can only be used for low belt speeds.

With an arrangement according to the invention one achieves a continuous measurement of the distribution of the Belt tension over the belt width in connection with the fact that the belt is passed over a deflection roller will. The invention is characterized in that the surface of the deflection roller at least one Contains pressure-sensitive zone, which is helical in relation to the longitudinal direction of the deflection roller runs. The pressure-sensitive zone is preferably created with the help of pressure-sensitive organs, d. H. Encoders, which contain at least one measuring part and a number of resilient elements, the hysteresis-free are connected to the measuring part and the sensors in the pressure-sensitive zone hold fixed.

With such an arrangement one obtains a constant scanning of the distribution of the strip tension transversely to the rolling direction. The helical arrangement of the pressure-sensitive zone becomes the point of contact of the tape with the pressure-sensitive zone moved over the tape and the process is repeated with each rotation of the roller. This is in the following in connection with the description

809 519/283

Exercise of the invention explained in more detail. In the drawing shows

Fig. 1 shows a deflection roller with a helical, pressure sensitive zone,

F i g. 2 the arrangement of a transmitter in a groove of the roller,

F i g. 3 another arrangement for forming a pressure-sensitive zone,

F i g. 4 and 5 two circuits for taking signals from the pressure-sensitive zone,

Fig. 6 shows an arrangement for assembling the signal received from the transmitter for the local Strip tension with a signal received from the strip tension meter, which corresponds to the nominal value of the local strip tension,

F i g. 7 shows an example of the signals for the local strip tension received from the transmitter in the deflection roller as well as the parts of the signal which are necessary for special tasks of the arrangement according to FIG. 6 can be taken and

8 shows in detail the measuring elements in the deflecting roller.

F i g. 1 is a schematic representation of a deflection roll of a rolling mill with a pressure-sensitive

F i g. 2 shows in section how according to the invention the pressure-sensitive zone can be designed. In the outer surface of a shaped like a hollow cylinder Deflection roller 1, a groove 2 is arranged. 5 The groove expediently has a flat bottom surface 3, while its side edges running at right angles to the bottom surface are designed with a shoulder 4 are. A transmitter made of magnetostrictive material consists of a measuring part 5 ίο and four resilient webs 6 attached to the side of the measuring part, which are made in one piece with the measuring part or are connected to the measuring part in some other hysteresis-free manner. At their farthest the ends located from the measuring part, the webs 6 are connected to one another in pairs by end pieces 7. These end pieces have projections 8 which cooperate with said shoulders 4. The measuring part 5 is provided on its lower edge with a projection 9 which rests on the bottom of the groove. The measuring part has a similar projection 10 on its upper edge. The length of the resilient elements 6 is chosen so that the encoder is fixed laterally against the vertical walls of the groove. Likewise is the height of the end pieces 7 chosen so that the spring

union zone according to the invention. The pressure-sensitive webs 6 the encoder in the vertical direction by means of The zone is helical around the roller of the projections 8 against the shoulders 4 and the front the surface of which is arranged and does not include jump 9 hold fixed against the bottom 3 of the groove, quite the circumference of the roller. The tape is attached to the encoder must be so tight that the the deflection roller at an angle of about 10 to centrifugal force not caused by the resilient webs 6 20 ° bent and is due to the pressure-sensitive pretension obtained at the bottom of the groove Zone along a short distance. The length that can.

the contact distance depends on the diameter of the measuring part 6 are four holes 11, 12, 13 and 14

steering roller, arranged by the deflection angle and the width. In the holes 11 and 12 there is a Mader pressure sensitive zone. When the tape magnetization winding 15 is attached and rolls on one around the deflection roller, the contact point 35 magnetization current source 16 is connected. Those of the tape and the pressure-sensitive zone via holes 13 and 14 are provided with a measuring winding 17 the width of the tape periodically along a line which is displaced on a measuring instrument 18 which is angled with the rolling direction. The magnetizing winding generated forms less than 90 °. If the helical line has magnetization fluxes around the constant slope in a known manner, the contact point 40 becomes holes 11 and 12 around it. Moved in the measuring winding along a straight line on the tape. 17 induced voltage is dependent on The helical line must not be the whole of the force acting on the encoder.
Include the circumference of the deflection roller, because otherwise the order to bridge the groove and the roller one

Giving the tape a smooth surface with every turn of the deflection roller is a problem a short time at two points of the pressure- 45 relatively thin cylinder 19 surrounded, the on sensitive zone would be applied at the same time. the upper projection 10 of the measuring part rests. Of the

The pressure-sensitive zone preferably consists of a part of the outer cylinder that is above the groove from one in the surface of the deflection roller to be so weak that it does not itself have any substantial arranged helical groove with constant slope part of the band pressure but absorbs the pressure transmission and with one or more in the groove 50 to the greatest possible extent to the encoder, set donors. If the groove only detects one encoder. 3 shows another way of training

holds, it must be long enough that the tape does not cover the pressure-sensitive zone. From magnetoihre Ends. If multiple donors are in strict material, rings 20 are punched, whose the groove are arranged, they are expedient in inner diameter to the outer diameter of the like Connected in series. The donors are of the type that 55 desie a hollow cylinder 1 shaped deflection roller emit an electrical output signal when she speaks. Near the outer edge of the ring there will be two exposed to the influence of a mechanical force by a narrow web 22 separate elongated holes will. The output signal is preferably punched out 21, which form the measuring zone. The Rings proportional to the mechanical force. Since the tape 20 are so placed on the cylinder 1 that in relation to the pressure-sensitive zone they are in good contact with it and somewhat in relation to it moderately limited area is applied, the total will be shifted to each other in such a way that the holes Output signal proportional to the pressure of the belt 21 form two channels that helically around the against the roller just in this area, d. H. per roller surface run in the specified manner, proportional to the tape tension in the part of the tape that becomes a magnetization winding in the channels attached to the deflection roller in the area mentioned, which encloses the narrow web 22 lies. This gives a continuous, cyclic and with this forms an inductive element, whose Lical scanning of the distribution of the strip tension across the inductance depends on the pressure on the web 22 to the rolling direction. . acts; the web is thus the measuring zone of the encoder.

To make the encoder as sensitive as possible, the encoder's measuring zone is made as narrow as possible. The tongues 24 located above the holes 21 form the elements that support the encoder, the but also serve here as a return path for the magnetic flux through the measuring zone. The one formed by the rings 20 outer surface of the cylinder can be sanded and used as a work surface for the deflection rollers to serve. The tape will lie directly against the elements 24. To wear the elements To avoid, however, it can be advantageous to have a cylindrical cylinder formed by the rings 20 To attach sleeve 25 made of wear-resistant material.

When the tape passes the measuring zone 22 during rotation of the deflection roller, the inductance of the inductive Element changed, and with the help of known measuring circuits, the pressure of the tape to be determined. It is also possible to use a reference inductance which is not influenced by the pressure of the tape 26, for example in the deflection roller, to be arranged and the two inductances in a known manner Way to a known measuring circuit 27 with a measuring instrument 28 according to FIG. 4 to be connected. This avoids errors that are based on temperature changes, because both Inductances are essentially the same temperature.

According to a further proposal of the invention, two further holes 29 are punched out in the ring 20, which are diametrically opposite to the two holes 21 described above. A magnetizing winding 30 is placed in the channels formed by the holes 29. If each of the Magnetizing windings 23 and 30 is divided into two separate windings and the four partial windings in a bridge according to FIG. 5 are interconnected, one gains the advantage that the unavoidable contact resistance between brushes and slip rings only the feed and measuring branches influence. The disadvantage of this embodiment, however, is that the pressure-sensitive zone is less than half the circumference of the deflecting roller, because there are two zones here that do not overlap may overlap, reducing the accuracy of the measurement of the strip tension distribution across the width of the Band is reduced to half at the same angle of deflection of the band.

Another modification of the invention is that the in F i g. 2 encoder shown by a Sector of the in F i g. 3 ring shown is replaced. This sector should then have the two holes 21 and so on have large parts on both sides of the holes that sufficient mechanical strength of the Segments and also get a sufficient magnetic return path for flux through the measurement zone will. If necessary, the donor can do this according to the type of FIG. 2 can be installed.

The donor according to FIG. 2 is expediently made up of a number of elements consisting of magnetostrictive Material, e.g. B. transformer sheet, are punched. When inserted into the groove 2, the individual sheet metal elements placed in the groove that the lower projection 9 is directed forward, they are then erected in the vertical position and pressed against the previously inserted elements. the Sheet metal elements can be coated with a hardenable resin before insertion Pressing the individual elements together is hardened. This gives you a very homogeneous one Measuring body that is well clamped in the groove.

To the sheet metal rings according to F i g in a simple manner. 3 so that holes 21 and 29 Form helical channels, each ring receives a lip 31, which in a corresponding helical groove on the outside of the hollow cylinder 1 must be fitted.

ίο F i g. 6 shows an arrangement for assembling the signals received from the encoder for the local strip tension with a signal that corresponds to the setpoint of the tape tension and is obtained from a tape tension knife assigned to the deflection roller is and is influenced by it. Certain circles belonging to this arrangement are of signals controlled, which are derived from an angular position encoder coupled to the deflection roller. That signal received from the arrangement is sent to an in-

zo instrument supplied, for example a cathode ray oscillograph, which shows how the belt tension varies along the belt width. The arrangement is on the Established fact that a certain relationship between the thickness and the tensile stress of the different, in the longitudinal direction extending fibers of the tape prevails. This means that one - when you determine the size of the tape tension in the various longitudinal fibers of the tape can - so that the strip thickness is also displayed at various points across the strip. A fiber is here defined as a strip of tape, the width of which is the length of the length of the roll axis may correspond to that of a single cooling mouthpiece or a group of individually controlled Cooling mouthpieces are served, so that the tension and thus the length of each fiber through Regulation of the cooling flow of the corresponding mouthpiece or the corresponding group of mouthpieces can be controlled individually.

In Fig. 6 and 7 denotes 31 in FIG. 1 shown deflection roller with a helically arranged Giver. The deflecting roller is combined with a band tension knife 32 known per se, which indicates the total belt tension acting on the belt.

Furthermore, an angular position encoder 33 is assigned to the deflection roller, which in turn controls an arrangement 38, which emits a signal dependent on the position of the deflection roller, i.e. periodically once per revolution the deflection roller is repeated. The deflection roller 1 is provided with signal transmission elements 34 provided, which can consist of slip rings and brushes or a wireless transmission or a may be other suitable devices. In an arrangement 35 a signal is obtained which is proportional to the local strip tension acting on the encoder.

The tape draw knife 32 is with an arrangement 36 for manual adjustment of the current width and Thickness of the tape combined so that a signal is obtained via an arrangement 37 known per se, which corresponds to the average value of the tension and thus the average thickness of the strip. This The value is called the setpoint of the local strip tension. The tape draw knife is also available with arrangements provided for the compensation of the variability of the encoder and the variation of the deflection angle, which occurs when the amount of rolling stock on the reel varies. Such arrangements are known

so that they do not need to be described in detail here. If the correct value of the bandwidth and Belt thickness is set and the belt tension is evenly distributed, d. H. the tape is evenly thick the measured local strip tension corresponds to the nominal value of the local strip tension.

The signals from the arrangement 38 are fed to a grid circle 39. The grid circle has three outputs 91, 92 and 93. Output 91 is during interval A in FIG. 7 open, ie during the part of a revolution of the deflection roller in which the tape is not in contact with the encoder and the signal emanating from there should be zero. The exit 92 is open during the interval B , which comprises a relatively large portion of that portion of one revolution of the idler roller in which the tape abuts the encoder. The output 93, on the other hand, is open during interval C, which comprises a relatively small part of interval B. The interval C expediently comprises that part of a revolution in which the central part of the belt is in contact with the encoder. Control signals for controlling arrangements, which are explained below, are taken from the three outputs.

The signal emanating from the arrangement 35 is fed to a summing arrangement 40, the output 41 of which is provided with a zero adjustment arrangement 42. This can consist of a DC powered potentiometer or any known electronic device. The zero adjustment arrangement is connected to the summing arrangement 40 and is controlled by the output 91 of the grid circuit 39. When the output 91 opens, the zero adjustment arrangement 42 starts and adjusts itself so that the output signal from the summing arrangement 10 is zero. This adjustment takes place in interval A in FIG. 7 instead of when the signal from the arrangement 35 is to be zero, this compensates for any variability of the encoder of the deflecting roller. The summation arrangement 40 is connected to a sensitivity adjustment arrangement 43 which is controlled by the output 91 of the grating 30 and is therefore only effective during the interval A. The signal coming from the summing arrangement 40 passes the sensitivity adjustment arrangement and is fed to both a second summing arrangement 41 and a third summing arrangement 45. The third summing arrangement 37 is also supplied with the signal generated in the arrangement 37, which corresponds to the nominal value of the local strip tension, and the difference between the two signals is supplied to an integrator 46. The integrator is put into operation by pulses from the output 92 of the grid 39 during the interval B and thus integrates the difference between the two signals during the interval mentioned and feeds the result to the sensitivity adjustment arrangement 43 in which the supplied integral is stored. The sensitivity of the arrangement 43 is only adjusted in the interval A, when the output 91 of the grid 39 is opened. During this interval the measurement signal is zero and the arrangement 43 can be adjusted without disturbing the measured value. The sensitivity must be adjusted because normally only a small part of the measuring range of the transmitter is used and a variability of the transmitter could cause abnormally large or small signals that would make reading on the oscilloscope screen difficult. The sensitivity adjustment corrects the sensitivity with each revolution of the deflection roller, which helps to stabilize the signals fed to the oscilloscope.

In the summation arrangement 41, the difference between the signals for the local strip tension and the nominal value of this strip tension, which comes from the arrangement 37, is formed. The signal difference passes through a filter 47 and is then fed to a fourth summing arrangement 48, to which an arrangement for bringing about automatic image centering 40 is connected. This arrangement works during a short interval C, which is expediently laid in that part of the revolution of the deflection roller in which the center of the belt rests on the encoder in the deflection roller and causes the center of the image on the oscilloscope screen, along the X-axis calculated, always lies on the same axis. This has the advantage that you always have the largest possible space for the image in the direction of the axis. After the image has been centered in the arrangement 48, the signal is fed to the vertical axis of the oscilloscope 50. The horizontal axis of the oscilloscope is supplied with a signal from the arrangement 38 which is proportional to the axial position of the part of the transducer of the deflection roller which is in contact with the belt.

On the screen you get a picture that shows how the strip tension is transverse to the rolling direction varies, with the center of the image in the center of the screen. The signal corresponding to the picture can of course be used in a manner known per se to control arrangements in the rolling mill be e.g. B. the aforementioned cooling mouthpieces, so that the tape thickness is even and the tape tension is evenly distributed over the tape.

Claims (18)

Patent claims: 1. Arrangement in strip rolling mills to measure the distribution of the strip tension along the Band width in connection with the guidance of the rolling stock over a deflection roller, thereby characterized in that the surface of the roller (1) has at least one pressure-sensitive Zone (2) which runs helically in relation to the longitudinal direction of the pulley. 2. Arrangement according to claim 1, characterized in that the pressure-sensitive zone (2) is obtained with the aid of an encoder which contains at least one measuring part (5) and a number resilient webs (6), which are hysteresis-free with the measuring part (5) and the encoder in the Keep the pressure-sensitive area fixed. 3. Arrangement according to claim 1, characterized in that the pressure-sensitive zone is arranged in a cylinder which is punched out of rings (20) made of magnetostrictive material Holes (21) is constructed, which together helically extending channels with an intervening pressure-sensitive ■ Form web (22). 4. Arrangement according to claim 3, characterized in that that the holes (21) punched out in the rings (20) are elongated, that their ίο Longitudinal direction is mainly parallel to the cylinder surface and that it is through a narrow, radially directed web (22) are separated, which forms the measuring zone of the elements. 5. Arrangement according to claim 4, characterized in that the number of punched out Holes (21) is two and that they are at the same radial distance from the cylinder axis. 6. Arrangement according to claim 4, characterized in that the number of punched out Holes (21, 29) is four and that they are arranged in two diametrically located groups. 7. Arrangement according to claim 3, characterized in that the one formed by the rings (20) Cylinder is surrounded by a cylindrical shell (25) made of wear-resistant material. 8. The arrangement of claim 1, wherein the pressure-sensitive zone consists of at least one in the deflection roller arranged helically extending groove and one arranged in the groove Encoder consists, characterized in that such an encoder consists of a measuring part (5) and consists of a number of resilient webs (6) extending from this part, which hold the encoder in the groove fix. 9. Arrangement according to claim 8, characterized in that the encoder with four resilient Web (6) is provided, the ends of which are furthest from the measuring part (5) with surfaces to rest are carried out on substantially radially extending sides of the groove. 10. Arrangement according to claim 8, characterized in that the groove (2) with substantially parallel to the surface of the deflection roller shoulders (4) through which the encoder is held in the groove and biased at the bottom of the groove. 11. The arrangement according to claim 8, characterized in that the deflection roller (1) of is surrounded by a thin metal cylinder (19) which covers the groove and rests against the encoder. 12. The arrangement according to claim 3, characterized in that a magnetizing winding (23) is arranged in the channels and encloses the intermediate web. 13. Arrangement according to claim 5, characterized in that that in the holes of the S. Rings (20) formed channels a magnetization winding is arranged, which has a measuring inductance forms that the reference inductance is arranged in the cylinder and both inductances are connected to a known measuring bridge. 14. Arrangement according to claim 6, characterized in that a magnetization winding is arranged in the two channels (21) of each group, which is divided into two preferably equal parts, and that these four parts are switched on in a measuring bridge known per se. 15. Arrangement according to claim 1, characterized in that the pressure-sensitive zone contains a number of transmitters whose output signals are proportional to the pressure with which the Tape rests against the encoder and is therefore proportional to the local one acting on the deflection roller (31) Tape tension that the deflection roller is assigned a tape tension knife (32), the output signal of which is corrected so that it is proportional to the nominal value of the local tape tension and that the Arrangement includes a summing arrangement (44). 16. The arrangement according to claim 15, characterized by an arrangement for automatic Zero adjustment (42) of the signals for the measured local tape tension during the time in which the tape is not in contact with the pressure-sensitive zone of the deflection roller. 17. Arrangement according to claim 15, characterized by an arrangement (46) for the integration of said difference signals during any part of the time that the tape rests against the pressure-sensitive zone. 18. Arrangement according to claim 17, characterized by a sensitivity adjustment arrangement (43), the said integrating difference signal as well as the signal for the local tape tension and its output signal for the variability of the encoder is compensated. Considered publications:
German Patent No. 877 834;
"Siemens-Zeitschrift", issue 10/1963,
to 735. For this purpose 2 sheets of drawings 809 519/283 3.68 ® Bundesdruckerei Berlin