Descriptive report on invention patent : "TELESCOPICITY CORRECTOR DEVICE FOR HOT STRIP MILL"

The current invention refers to teiescopicity corrector device for hot strip mill , more accurately , a system installed on the subsequent stage to the steel strip coiling in the hot rolling process where the formed coil is positioned in its horizontal or vertical axle and pressured by two disks which are centered in the coil axle , thus correcting the teiescopicity of the product .

The presence of teiescopicity causes some problems for the subsequent handling of the mentioned coils , and their relevance is straight related to the characteristics of transport, movement of coils and also to further processing to which the metal is destined to .

Teiescopicity is a physical phenomenon that occurs in the steel strip coiling phase resulting on the rolling process ; this factor can occur through a series of variables on the output process , such as ; deviation of the line in the center of the strip , wearing of puller rolls, mandrel ( chuck , reamer ) unevenness on the side guards opening of the coiler entry , among others .

Though in some situations it is possible to minimize teiescopicity through parameters adjustments in rolling , such as leveling of work rolls in roughing mill and finished train , homogeneity of temperature across the cross section of the plate, frequency gaging ( calibration ) of side guards and puller rolls .cautious changes of wearing plates among others .

There is a pratic limit for these adjustments that are cautious. For a corrective adjustment reprocessing of coils on subsequent lines are used for a corrective adjustment , and this adds cost production , storage , transport , new process beyond a possible commitment on the delivery term of the product to the client . Another existing corrective form is through press-type system , however for coils with axle in vertical causing in some cases kneading ( mashing ) of teiescopicity threads , just correcting one of the sides . Taking into consideration that the phenomenon teiescopicity is aleatory , coils present teiescopicity with high or low grade and from the commercial point of view this changeability ( variability ) is undesirable since each rolling mill has its own adjustment .In view of that , there is a lack of technique in resources in the state that allows reduction of teiescopicity in coils without running over to changes moreover on efficient stages that can add costs to global process . In order to supply this lack teiescopicity corrector device for hot strip mill was created; a device through which coil has its teiescopicity corrected in a controlled way without causing shape and surface defect ( flaw ) providing quality control on the finished product so that it does not alter the other efficient stages The current

invention enables reduction or elimination of coils .It is described based on the attached figures , where : "

Figure 1 presents a view in perspective of the set of towers where telescopicity of the coils will be reduced or eliminated . Figure 2 presents a detailed system and shows the beginning of working ( running ) .As it can be observed in the figures , telescopicity corrector device ( 1 ) of coils in hot strip rolling mill consists of split tower (4) fixed in a vertical position. This tower has a hydraulic vertical cylinder centralized in its upper part (5) whose function is to measure the outside diameter of the coil (2) to inform the system the right position of an axle and that it has an inner tear ( groove ) (6) where hydraulic cylinders that have horizontal and vertical displacement (shift) are inserted (7) and that it has in its end correction disk (3) that will be pressured on the side faces of the coil(2) reducing or eliminating telescopicity (1) of the same with the purpose of fitting the final value to the client's specification . When the coil leaves the rolling mill (2) it is arranged on a transport equipment (8) and led till the corrector device .

Once placed on the station hydraulic system (7) is vertically powered (driven ) until line the correction disk up(3) with the coil sector (2) where telescopicity was identified . Horizontal hydraulic set is powered , once alignment had been finished (7) till telescopicity (1) has been totally eliminated or reduced to maximum possible limit .It is important to notice that there is a established rate between the degree of telescopicity (1) to be corrected and mechanical stress to be applied in order to correct coil telescopicity (2) . For practical reasons the upper limit of this rate is restricted (limited) to mechanical resistance value of material and upper stress on established limit may cause damage to telescopicity threads (1) such as kneading or scratch, instead of correcting telescopicity only (I)undertaking the aims of the current invention . In order to avoid shape damages to the coil (2) and after surface strip , telescopicity correction process ( 1) is carried out through controls such as :

A. velocity approach : adoption of differentiated approximation velocity of horizontal cylinders (7) from a shaped distance that depends upon the width of the coil (2) based on known values using position transducers ( device that informs the hydraulic cylinder real position (7) to control system . B. rapid detection of the first contact : the first contact position is defined as the moment when correction disks (3) touch the coil threads (2) and this point is determined through the measurement of pressure by the transducer installed on

horizontal hydraulic cylinders (7) after identifying a high rate of pressure variation or extent of a limit pressure value shaped in control system .

C. limit power ( strength) / correction velocity : according to the characteristics of material maximum power and speed values needed for correcting telescopicity are established in control system .

D. estimation of the initial and final telescopicity value : (1) the initial and final telescopicity value can be estimated respectively using the value of the medium strip width informed by the system by calculating the difference on the relative position of horizontal hydraulic cylinders . Telescopicity corrector device for hot strip mill provides immediate solution to the phenomenon telescopicity (1) and it is indispensable in order to avoid any change and/or adjustments on previous and subsequent stages to hot strip rolling , simplifying greatly its insertion together with the consumer market providing a coil (2) with acceptable levels of telescopicity . Telescopicity corrector device for hot strip mill will be incorporated to hot strip rolling mill enabling cost reduction of products concerning products rework where telescopicity is frequently observed , and it can also be used in other situations where there is coiling of materials and appearance of telescopicity .