GB1576022A

GB1576022A - Combination strip contacting device for use in a rolling mill

Info

Publication number: GB1576022A
Application number: GB8578/77A
Authority: GB
Original assignee: Wean United Inc
Current assignee: Wean United Inc
Priority date: 1976-02-19
Filing date: 1977-03-01
Publication date: 1980-10-01

Description

(54) COMBINATION STRiP CONTACTING DEVICE FOR USE IN A ROLLING MILL (71) We, WEAN UNITED, INC., a corporation organized under the laws of the State of Ohio, United States of America, of 347 North Park Avenue, City of Warren, Trumball County, State of Ohio 44481, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us,' and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a strip contacting device suitable for use between adjacent stands of a tandem rolling mill for performing selectively two functions on the strip.

At the present time, loopers, tensiometers and shapemeters, each taking the form of an arm with a roller -which contacts the strip as the strip travels from one stand to the other, are employed between adjacent mill stands of a tandem rolling mill. A looper, which is a constant strip tension exerting device is usually employed in a tandem mill arrangement to maintain the strip taut as the preceding stand delivers the product at a faster rate than that at which the succeeding stand is removing the strip.

Tensiometers are employed for measuring the strip tension. They are used to either indicator or to regulate tension between stands of tandem strip mills. In the case of regulating the tension, accurate controlled tension is mandatory since excessive tension tends to break the strip and insufficient tension may cause undesirable strip looping between the stands. Variation in strip tension also causes strip gauge variation.

Since it is desirable to produce, in a cold mill, a "good shaped" strp,,i.e. a flat strip, shapemeters are used to measure the contour of 'a strip by suitable sensors which transform these contour differences into 'e'-lec'trical signals. These signals enàble the operator or the automatic controls 'to make new'pessary adjustments to the roll'bending means, the screw down means, and/or the speed control means of the stands to cold pensate for the particular objectionable shape occurringin the strip. For, instance, if the edges of the strip are wavy, an adjustment may be made to .the roll . bending means to apply a force.in a direction to correct for this non-flatness in the strip.

Even though the above-mentioned, 'strip contacting devices were originally .con- structed to be limited to one particular mode of operation, in the past ten years or so, apparatuses have evolved which co,m- bine more than one mode of operation.

U.S. ' Patent No. 3,169,420 uses the same strip contacting device for one of three separate functions at three different times: (1) as a looper; (2) as a tensiometer; and (3) as a variable tension exerting means for gauge. control. In U.S. Patent No.

3,788,534, a strip engaging device permits both a looper function and a tensiometer function by utilizing a looper roller and.a tension measuring roller which are':moun- ted on separate arms of the same frame,., Due to the serious, and continuous, prob- lem of not'knowing strip shape and, strip tension distribution between stands when cold rolling some materials, such as silicon steel, performing at least two -of the identified functions is becoming more desirable.

Silicon steel is brittle and notch sensitive, and if subjected to uneven and improper tension patterns, strip breakage or cobbles result. Therefore, rolling of this material requires both a shapemeter and a looper having a long-stroke to follow the strip.

When carbon steels are rolled by. the same mill, a shapemeter and a tensiometer are desirable.

It is therefore, an object of this inven- tion to provide a .strip contacting.dévice capable of effecting two combination functions in an easy, economical, and highly efficient manner. According to the present invention, a device for contacting metal strip passing between adjacent stands of a.tandem.roll- ing mill comprises a roller assembly connected to an actuator for displacement thereby in a manner for said assembly to contact the underside of the metal strip across substantially the entire width thereof to assume a force transmitting relationship therewith, said assembly including shapemeter means sensitive to the shape of the strip and for producing a representation of the shape of the strip.

means for causing said roller assembly to move through a relatively large working range which corresponds to a combined shapemeter and looper function and for positioning the roller assembly in a substantially fixed location relative to a datum position of the strip and which corresponds to a combined shapemeter and tensiometer function and means for selecting a desired one of the two functions to be performed by the roller assembly.

In order that the invention may be more readily understood it will now be described, by way of example only, with reference to the accompanying drawings, in which: - Figure 1 is an elevational view of a preferred embodiment of the present invention located between two housing posts of a stand of a rolling mill; Figure 2 is a plan view of the roller and apron shown in Figure 1; Figure 3 is a sectional view of the strip contacting device taken along lines 3-3 of Figure 1; Figure 4 is a partial, sectional view of the device taken along lines 4-4 of Figure l, and Figure 5 is a schematic diagram of an electrical control system for selecting various modes of operation or sets of functions.

Referring first to Figure 1, there is illustrated a strip contacting device 1 situated between two housing posts 3-5 of a mill stand, which housing posts support two back-up rolls and two work rolls (not shown) for reducing steel strip. The construction and operation of the mill stand follows well-known practice, as does the strip contacting device per se. For purposes. of illustration, the device has been incorporated in a tandem cold rolling mill.

In' this Figure 1, several of the more important elements of the invention, such as an actuator in the form of a piston-cylinder assembly 7, frame 9, arm assembly 11, and shapemeter roller assembly 13 are illustrated. Roller assembly 13 may comprise one of several available shapemeter devices, which in the form shown comprises a roller- 15 almost entirely enclosed by a casing 17, except at the upper portion, and rotatably mounted by a shaft 19 in the casing by bearings 21. A more detailed explanation of the intended illustrated type of shapemeter and operation is set out in U.S.

Patent No. 3,499,306. To the left of the assembly 13 in Figure 1, is an electrical conduit 23, an air supply line 25, and a summing control box 27. As shown, the shapemeter roller 15 has several segmented sensor bearings 29, which relay differential pneumatic signals to be converted in the control box into differential electrical signals representing the contour of the strip as the under surface of the strip contacts roller 15. Nuts and bolts 33 enable roller assembly 13 to be secured to or removed from arm assembly 11 as a unit. Locating pin 35, mounted on the arm assembly, properly locates roller casing 17, thereby properly aligning the bolt holes.

Figure 2 illustrates the positioning of the roller assembly 13 relative to apron 37 of arm assembly 11, which apron 37 receives the leading end of the strip as it passes between the stands during the threading operation. Shaft 39, shown in Figure 2, but better shown in Figures 3 and 4, pivotally mounts arm 11 in bearings 41 secured to frame 9.

Referring now to Figure 3, one is able to better appreciate how roller assembly 13 is secured to a shelf 43 of arm assembly 11 and how roller 15, when raised, deflects the strip above the passline of the mill, the strip and passline being indicated in Figure 3. Arm assembly 11, with roller assembly 13, is raised by piston-cylinder assembly 7 whose piston rod 45 has a clevis 47 for pivotally connecting to bracket portion 49 of arm assembly 11. Associated with cylinder assembly 7 is a pressure transducer 51 and a variable pump 53 whose detailed inter-relationships and operation appear in U.S. Patent No. 3,169,420, and more about which will be said later in explaining the operation of the invention.

The piston-cylinder assembly 7 is trunnion mounted in frame 9 (see best in Figure 1).

It will be appreciated that cylinder assembly 7, arm assembly 11, shaft 39, and clevis 47 for a self-compensating linkage system according to the description set forth in the aforesaid U.S. Patent No. 3,169,420.

By virtue of this, a constant tension can be maintained on the strip for a wide range of movement of the roller while maintaining constant cylinder pressure.

Still referring to Figure 3, a selsyn 55 for indicating the arcuate positioning of arm assembly 11 when raised and lowered by piston-cylinder assembly 7 is supported on top of frame 9. 'Rotatably mounted at one end of selsyn 55 is gear 57, which meshes with the teeth of a segmental section 59 of arm assembly 11 as the assembly moves in its arcuate path. As one views Figure 4, it is apparent that an extreme positioning of roller 15 is achieved by adjustable stops 61 contacting wearplates 63 of arm assembly 11. Each adjustable stop 61 is mounted in frame 9.

Turning now to the electrical control in Figure 5, there is shown a mode selector 65, having a dial 67 for selecting one of the five indicated positions associated with the illustrated electrical circuit. The electrical circuit comprises power lines L1 and L2.

The first line L3 located between lines L1 and L2, has a switch 69, a contact 71, and a control relay CRl. Similarly, line L4 has switch 73, contact 75, and control relay CR2, and lines L5 and L6, have switches identified as 77 and 79, contacts as 81 and 83, and the control relays as CR3 and CR4, respectively. As shown, control relay CR1 has contacts in line L7, which connects a shapemeter control 85 of the main control 87 between lines L1 and L3; control relay CR2, has contacts in a line identified as line Lilo, connecting a looper control 89 between lines L1 and L3. Control relay CR3 has contacts in two lines Ls and L,1, which are connecting shapemeter control 85 and looper control 89 respectively between lines L, and IL. Finally, control relay CR4 also has electrical contacts in lines L9 and Ll3 which connect shapemeter control 85 and tensiometer control 91, respectively between lines L1 and L2.

With the foregoing in mind, a brief explanation of the operation of the strip contacting device 1 will now be given. It is to be noted that single functions can be achieved, which functions will be explained first. If a shapemeter function is desired, the operator of the mill turns dial 67 to mode No. 1, which only energises control relay CR1. Control relay CR1 closes contact CR1 which energises shapemeter control 85. This, in turn, actuates the differential pressure transducers (not shown) in roller assembly 13, and supplies air to the sensor bearings 29. In this particular operation, roller 15 of assembly 13 is to be held approximately one inch above the passline by piston rod 45. Prior to this, the operator has set stops 61 to position roller assembly 13 in the required opera- ting position and causes pump motor assembly 53 to deliver to the piston-cylinder assembly 7 hydraulic fluid pressure sufficient to hold arm assembly 11 against stops 61. The strip, under tension, is advanced over the segmented sensor bearings 29 of shapemeter roller assembly 13. The tension profile across the strip width results in a corresponding differential pressure profile across the segmented sensor bearings.

The differential pressures, in turn, are converted into corresponding electrical profile.

If a looper function is desired, the operator turns dial 67 of the mode selector 65 to mode No. 2, which only energises control relay CR2, which then closes contact CR2. By this, looper control 89 is activated. The operator, prior to turning the dial 67 to mode No. 2, adjusts stops 61 to allow the relatively wide range of travel of the roller assembly 13. The motor pump 53 exerts, in this case, constant desired pressure on the cylinder assembly 7.

The selected pressure will be chosen to give a desired strip tension. As described in U.S. Patent No. 3,169,420, the linkage system conipensates for the change of' ge'o- metry for the strips that for a constant cylinder pressure, a constant strip tension will be obtained even though the roller 15 travels over a relatively wide arc. During the pivotal movement of arm 11, the teeth of segmental section 59 rotates gear 57 to effect operation of selsyn 55, whereby, in accordance with well-known rolling mill control practice, the position of the roller assembly 13 is monitored.

A combined shapemeter and looper function is achieved quite easily by moving dial 67 of the selector 65 to mode No. 3, which brings into effect through the various electrical components both the shapemeter and looper controls 85 and 89, respectively.

The operation of the cylinder assembly 7 and the adjustable stops 61 is the same as in mode No. 2. During this selected mode, roller assembly 13 allows an application of constant tension over a wide range of strip travel, and a concurrent and continuous determination of the strip shape characteristics; that is, the flatness characteristics of the strip. Because of the extended travel of the looper, there will be a varying resultant force profile on the segmented sensor bearings 29 depending upon the vertical location of the roller. This is so because the sensor bearings measure the vertical force components, which components vary with the angles between the strip and the sensor bearings. For this reason, in Mode 4 in order to sum the outputs of the sensor bearings to obtain a total tension value, the roller assembly 13 must be maintained in a fixed position. Consequently, the vertical force profile, while changin'g in' magnitude will remain representative of the tension profile across the strip width.

Mode No. 4 represents a combined shapemeter and tensiometer function.

When dial 67 is turned to this mode, the related electrical component controls 85 and 91 are energised. The operation of the cylinder assembly and positioning of the strip corresponds to mode No. 1. During this selected mode, the roller assembly 13 allows both an accurate measurement of total strip tension and a concurrent and continuous measurement of the shape of the strip. Total tension may be read either by totalling the individual readouts of tlic affected segmented bearings of roller 15 by summing control box 27 or by pressure transducer 51 associated with the pistoncylinder assembly.

WHAT WE CLAIM IS: - 1. A device for contacting metal strip passing between adjacent stands of a tandem rolling mill, said device comprising a roller assembly connected to an actuator for displacement thereby in a manner for said assembly to contact the underside of the metal strip across substantially the entire width thereof to assume a force transmitting relationship therewith, said assembly including shapemeter means sensitive to the shape of the strip and for producing a representation of the shape of the strip, means for causing said roller assembly to move through a relatively large working range which corresponds to a combined shapemeter and looper function and for positioning the roller assembly in a substantially fixed location relative to a datum position of the strip and which corresponds to a combined shapemeter and tensiometer function and means for selecting a desired one of the two functions to be performed by the roller assembly.

2. A device as claimed in claim 1, where the selecting means have shapemeter-looper activating circuits for activating the shapemeter-looper function and shapemeter-tensiometer activating circuits for activating the shapemeter-tensiometer function.

3. A device as claimed in claim 1 or 2, wherein the roller moving means comprise means for causing said actuator to exert a desired force on said strip during said working range, and an adjustable stop means engageable with said roller assembly for positioning said roller in said fixed location.

4. A device as claimed in claim 1, wherein said roller assembly comprises an arm assembly pivotally connected to a frame, and where during said relatively large working range a substantial change takes place in the geometry of said strip relative to the passline of the mill, said arm assembly being characterised by a linkage system adapted to vary the force exerted by said actuator in a manner that for a constant actuator force a constant tension is obtained throughout said working range.

5. A device as claimed in any preceding claim, wherein said actuator comprises a piston-cylinder assembly, and means associated with said piston-cylinder assembly for measuring the pressure applied thereto to determine the total tension exerted by said strip during the shapemeter-tensiometer function.

6. A device as claimed in claim 4, wherein said roller means further comprises a plurality of means for measuring the transverse tension profile of said strip, and means for totalising the results of said measuring means to produce a representation of the total tension between said strip and said roller means during said shapemeter-tensiometer function.

7. A device for contacting metal strip passing between adjacent stands of a rolling mill to perform various functions on the strip, said device being substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. by totalling the individual readouts of tlic affected segmented bearings of roller 15 by summing control box 27 or by pressure transducer 51 associated with the pistoncylinder assembly. WHAT WE CLAIM IS: -

1. A device for contacting metal strip passing between adjacent stands of a tandem rolling mill, said device comprising a roller assembly connected to an actuator for displacement thereby in a manner for said assembly to contact the underside of the metal strip across substantially the entire width thereof to assume a force transmitting relationship therewith, said assembly including shapemeter means sensitive to the shape of the strip and for producing a representation of the shape of the strip, means for causing said roller assembly to move through a relatively large working range which corresponds to a combined shapemeter and looper function and for positioning the roller assembly in a substantially fixed location relative to a datum position of the strip and which corresponds to a combined shapemeter and tensiometer function and means for selecting a desired one of the two functions to be performed by the roller assembly.