METHOD FOR AUTOMATICALLY ZEROIZING A UNIVERSAL EDGER STAND

Description

Technical field

[0001] The present invention generally relates to a method for automatically zeroizing a universal edger stand for rolling H-section products.

Background Art

[0002] A universal edger stand (UE stand) is a rolling stand capable of simultaneously fulfilling the function of a classical universal roughing stand (UR stand), i.e. rough-rolling the flanges and the web of an H-section product, and an edger stand (E stand), i.e. rolling the flange tips of such a product. Such a UE stand is normally used in a tandem arrangement with a classical UR stand, warranting an excellent dimensional accuracy, while simultaneously increasing productivity of the rolling operation.

[0003] Just as the classical UR-stand, the UE-stand comprises a set of four rolls: i.e. an upper horizontal roll, a lower horizontal roll, a left side vertical roll and a right side vertical roll. Each of the horizontal rolls has a cylindrical surface, which are cooperating for rough-rolling the web. Each of the vertical rolls has an upper conical surface cooperating with a conical flank of the upper horizontal roll and a lower conical surface cooperating with a conical flank of the lower horizontal roll for rough-rolling the flanges. In distinct contrast to a classical UR-stand, each of the horizontal rolls additionally has two shoulder surfaces for rolling the flange tips.

[0004] US A 4 702 099 describes a method for automatically adjusting the rolls in a universal type rolling mill stand. This prior art method comprises following steps:

(1) adjusting the lower roll in a vertical direction and corresponding to its rolling diameter and in particular relation to a horizontally extending centre plane of rolling (corresponding to the pass line of the stand);

(2) adjusting the upper roll towards the lower roll at a relatively low speed until rolling pressure is indicated through separate pressure measurement;

(3) retracting slowly the upper roll until rolling pressure has reduced to zero;

(4) releasing the upper roll as far as its axial disposition is concerned;

(5) moving the vertical rolls towards each other, said vertical rolls being in abutment with said upper roll so that upon movement of the vertical rolls the upper roll is shifted to a position such that both said vertical rolls abut the sides of the lower roll;

(6) arresting the axial position of the upper roll;

(7) moving all rolls to attain rolling pressure; and

(8) ascertaining values indicative of respective positions for the rolls after completion of all preceding steps.

[0005] While this prior art method allows a simple, fast, fully automated and precise zeroizing of a universal type rolling mill stand, it can unfortunately not be used on a universal edger stand as described hereinbefore, because in such a UE-stand it is impossible to have simultaneous contact (kissing) of the four rolls of the stand.

Technical problem

[0006] It is an object of the present invention to provide a method for automatically zeroizing a universal edger stand for rolling H-section products.

[0007] This object is achieved by the method as claimed in claim 1.

General Description of the Invention

[0008] To achieve this object, the present invention proposes

Brief Description of the Drawings

[0009] A preferred embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings in which:

Fig. 1 to Fig. 6 illustrated the progressive stages of zeroizing a universal edger stand in accordance with an embodiment of the present invention, wherein the stand is schematically represented by its four rolls; and

Fig. 7 is a detail of Fig. 6 illustrating computation of zero values X₀ for vertical rolls.

[0010] Further details and advantages of the present invention will become apparent from the following detailed description of several embodiments with reference to the attached drawings, wherein:

Description of Preferred Embodiments

[0011] Fig. 1 to 6 schematically show a roll set 10 of an universal edger stand (UE-stand) used for rolling an H-section product having a web and two flanges (as e.g. a H-beam or a H-shaped sheet-pile). This roll set 10 includes a pair of horizontal rolls 12, 12'(shown only by half), each roll 12, 12' having an horizontal axis of rotation 13, 13', and a pair of vertical rolls 14, 14', each roll 14, 14' having a vertical axis of rotation 15, 15'. Each of the horizontal rolls 12, 12' has a cylindrical rolling surface 16, 16' for rolling the web of the H-section, two shoulder rolling surfaces 18, 18' for rolling the flange tips and two conical rolling flanks 20, 20'. Each of the vertical rolls 14, 14' has a lower conical rolling surface 24, 24', cooperating with one of the two conical rolling flanks 20 of the lower horizontal roll 12, and a symmetrical upper conical rolling surface 22, 22' cooperating with one the two conical rolling flanks 20' of the upper horizontal roll 12' for rolling the flanges of the H-section. It is to be understood that the UE stand further includes a roll support frame (not shown) in which the four rolls 12, 12', 14, 14' are mounted. The latter are preferably equipped with double effect hydraulic actuators (capsules) acting with different pressure on piston and rod side. The hydraulic actuators are position and pressure controlled. An automation system calculates the actual roll force applied on the stands due to the rolling process. A computer (not shown) is used to control the positions and movements of the rolls in function of the signals of linear transducers and predefined set values and reference values.

[0012] To achieve the position shown in Fig. 1, the vertical rolls 14, 14' are first horizontally spaced apart so as not to impede a vertical movement of the horizontal rolls 12, 12'. Then, the lower horizontal roll 12 is vertically moved a computed distance D from a lower reference position, which is determined by a mechanical stop (not shown), into a predefined zero position. This distance D is computed in function of the diameter of the horizontal roll 12 so that in said predefined zero position, the horizontal roll 12 has its upper generatrix in the pass line of the stand, which is identified in the figures by a doted line 28..

[0013] Fig. 2 illustrates a first roll kissing, during which the upper horizontal roll 12' is pressed with rolling pressure against the lower horizontal roll 12. To achieve this first roll kissing starting from the position shown in Fig. 1, the upper roll 12' is vertically lowered in a fast movement until it defines with the lower horizontal roll 12 a gap some millimetres (e.g. 3-6 mm). From this intermediate position, the upper roll 12' approaches the lower roll 12 in a creeping like movement, to be finally pressed against the lower roll 12, until a predetermined pressure, corresponding substantially to a web rolling pressure. In this first roll kissing position, the vertical positions of the lower horizontal roll 12 and the upper horizontal roll 12' are now measured and registered as zero values for the horizontal rolls 12, 12'.

[0014] To achieve the roll positions shown in Fig. 3, the lower horizontal roll 12 and upper horizontal roll 12' are spaced apart symmetrically about the pass line 28, so as to define a gap of a predetermined magnitude Y between them. This predetermined magnitude Y is chosen so that the vertical rolls 14, 14' can contact the conical flanks 20, 20' of the horizontal rolls 12, 12' without being hindered by the shoulder rolling surfaces 18, 18'.

[0015] Fig. 4 and 5 illustrate axial aligning of the horizontal rolls 12, 12'. Fig. 4 shows that the upper horizontal roll 12' is, after release (opening) of its horizontal fixing system, first axially moved a few millimetres towards the roll changing side (see arrow 29). The lower horizontal roll 12 remains however axially fixed against an axial reference end stop 30. Fig. 5 shows that the vertical roll 14 located on the roll changing side is then moved in a creeping like fashion towards the centre of the stand, thereby pushing the upper horizontal roll 12' towards the centre of the stand until this movement is stopped when the vertical roll 14 abuts with its lower conical rolling surface 24 against the conical flank rolling surface 20 of the axially fixed lower horizontal roll 12. The two horizontal rolls 12, 12' are now located vertically exactly one above the other or, in other words, axially aligned.

[0016] Fig. 6 illustrates a second roll kissing, during which the two vertical rolls 14, 14' are pressed with rolling pressure against the two, previously aligned horizontal rolls 12, 12'. To achieve this second roll kissing starting from the position shown in Fig. 5, the vertical roll 14' located on the drive side of the stand (i.e. the opposite side of the aforementioned roll changing side) is moved in a creeping like fashion towards the centre of the stand until it contacts on of the conical rolling flanks 20, 20' of the horizontal rolls 12, 12'. After this initial contact is achieved, both vertical rolls 14, 14' are simultaneously pressed against the vertically spaced horizontal rolls 12, 12', until a predetermined pressure, corresponding substantially to a typical flange rolling pressure, is measured by the pressure measuring gauges associated with the vertical rolls 14, 14'. In this second roll kissing position, the horizontal positions of both vertical rolls 14, 14' are now measured and registered as auxiliary zero values X₀' for the vertical rolls 14, 14'. At the latest at this stage, the axial position of the upper horizontal roll 12' can be fixed by closing its horizontal fixing system (generally a wedge-system) and axial zero positions can be registered for the two horizontal rolls 12, 12'.

[0017] Referring now to Fig. 7, which shows the vertical roll 14' "kissing" the two horizontal rolls 12, 12', computation of real zero values X₀ for the vertical rolls 14, 14' is now described. In Fig. 7, the Greek letter α identifies the angle between a generatrix of the cylindrical rolling surface 16, 16' and a generatrix of the conical rolling flanks 20, 20' of the horizontal rolls 20, 20'. During the roll kissing illustrated in Fig. 7, each of the horizontal rolls 12, 12' is spaced a distance Y/2 from the pass line 28. Dotted line 30 identifies the imaginary kissing position of the vertical roll 14 that would be achieved if the two horizontal rolls 12, 12' were in "kissing contact" too. This imaginary kissing position defines, on the pass line 28, the real zero value X₀ for the vertical roll 14. This real zero value X₀ can be computed in function of the auxiliary vertical zero values X₀', registered during said second roll kissing, the predetermined magnitude Y of the gap during said second roll kissing and said angle α with e.g. following formula:

[0018] It will be appreciated that a method in accordance of the present invention warrants a simple, fast, fully automated and precise zeroizing of a universal edger type rolling mill stand.

Claims

1. A method for automatically zeroizing a universal edger stand for rolling an H-section product having a web and two flanges, said universal edger stand including:

an upper horizontal roll (12') and a lower horizontal roll (12), each of said horizontal rolls (12, 12') having a cylindrical rolling surface (16, 16') for rolling the web, two shoulder rolling

surfaces (18, 18') for rolling the edges and two conical rolling flanks (20, 20'), wherein a is the angle between a generatrix of said cylindrical rolling surface and a generatrix of said conical rolling flanks; and

a first vertical roll (14) and a second vertical roll (14'), each of said vertical rolls having an upper conical rolling surface (22, 22') cooperating with one of said conical rolling flanks (20') of said upper horizontal roll (12') and a lower conical rolling surface (24, 24') cooperating with

one of said conical rolling flanks (20) of said lower horizontal roll (12) for rolling the flanges; said method comprising following steps:

spacing apart said vertical rolls (14, 14') horizontally so as not to impede a vertical movement of said horizontal rolls (12, 12');

vertically adjusting said lower horizontal roll (12') in a predefined zero position; achieving a first roll kissing by bringing said upper horizontal roll (12') in contact with said lower horizontal roll (12) and pressing it with rolling pressure against the latter; registering the positions of said lower horizontal roll (12) and said upper horizontal roll (12') during said first roll kissing as zero values for said horizontal rolls;

spacing apart said lower horizontal roll (12) and said upper horizontal roll (12') symmetrically about the pass line of said stand so as to define a gap of a predetermined magnitude Y between said two horizontal rolls, wherein said predetermined magnitude Y is chosen so that said vertical rolls (14, 14') can contact said conical flanks (20, 20') of said horizontal rolls (12, 12');

achieving a second roll kissing by pressing said vertical rolls (14, 14') with rolling pressure against said conical flanks (20, 20') of said horizontal rolls (12, 12');

registering the positions of said vertical rolls (14, 14') during said second roll kissing as auxiliary zero values X0' for said vertical rolls; and

computing real zero values X0 for said vertical rolls (14, 14') in function of said auxiliary vertical zero values X0', said predetermined magnitude Y and said angle α.

2. The method as claimed in claim 1, further comprising the step of:

axially aligning said horizontal rolls (12, 12') prior to achieving said second roll kissing.

3. The method as claimed in claim 2, wherein said step of axially aligning said horizontal rolls (12, 12') comprises the sub-steps of:

releasing an axial fastening system of said upper horizontal roll (12'), so that the latter can be axially moved towards a roll changing side;

axially moving said upper horizontal roll (12') a few millimetres towards said roll changing side; and

moving the vertical roll (14, 14'), located on said roll changing side towards the centre of said stand and pushing thereby said upper horizontal roll (12') towards the centre of said stand until said movement is stopped by either one of said horizontal rolls.

4. The method as claimed in any one of claims 1 to 3, wherein said real vertical zero values X₀ are computed as follows:

Ansprüche

1. Verfahren zur automatischen Nullpunkteinstellung eines Universalstauchgerüsts zum Walzen eines H-Profil-Produkts mit einem Steg und zwei Flanschen, wobei das Universalstauchgerüst Folgendes umfasst

eine obere Horizontalwalze (12') und eine untere Horizontalwalze (12), wobei jede der Horizontalwalzen (12, 12') eine zylindrische Walzfläche (16, 16') zum Walzen des Stegs, zwei abgesetzte Walzflächen (18, 18') zum Walzen der Kanten und zwei kegelförmige Walzflanken (20, 20') aufweist,
wobei α der Winkel zwischen einer Mantellinie der zylindrischen Walzfläche und einer Mantellinie der kegelförmigen Walzflanken ist; und
eine erste Vertikalwalze (14) und eine zweite Vertikalwalze (14'), wobei jede der Vertikalwalzen eine obere kegelförmige Walzfläche (22, 22'), die mit einer der kegelförmigen Walzflanken (20') der oberen Horizontalwalze (12') zusammenwirkt, und eine untere kegelförmige Walzfläche (24, 24'), die mit einer der kegelförmigen Walzflanken (20) der unteren Horizontalwalze (12) zusammenwirkt, aufweist, um die Flansche zu walzen;
wobei das Verfahren folgende Schritte umfasst:

horizontales Beabstanden der Vertikalwalzen (14, 14'), um so eine Vertikalbewegung der Horizontalwalzen (12, 12') nicht zu behindern; vertikales Anstellen der unteren Horizontalwalze (12) in eine vordefinierte Nullposition;

Erzielen einer ersten gegenseitigen Walzenberührung, indem die obere Horizontalwalze (12') mit der unteren Horizontalwalze (12) in Kontakt gebracht und mit Walzdruck gegen letztere gedrückt wird;

Registrieren der Positionen der unteren Horizontalwalze (12) und der oberen Horizontalwalze (12') während der ersten gegenseitigen Walzenberührung als Nullwerte für die Horizontalwalzen;

symmetrisches Beabstanden der unteren Horizontalwalze (12) und der oberen Horizontalwalze (12') rings um die Durchführungslinie des Gerüsts, um so einen Spalt mit einer vorbestimmten Größe Y zwischen den zwei Horizontalwalzen zu definieren, wobei die vorbestimmte Größe Y so gewählt wird, dass die Vertikalwalzen (14, 14') die kegelförmigen Flanken (20, 20') der Horizontalwalzen (12, 12') berühren können;

Erzielen einer zweiten gegenseitigen Walzenberührung, indem die Vertikalwalzen (14, 14') mit Walzdruck gegen die kegelförmigen Flanken (20, 20') der Horizontalwalzen (12, 12') gedrückt werden;

Registrieren der Positionen der Vertikalwalzen (14, 14') während der zweiten gegenseitigen Walzenberührung als Hilfsnullwerte x0' für die Vertikalwalzen; und

Berechnen der realen Nullwerte X0 für die Vertikalwalzen (14, 14') in Abhängigkeit von den vertikalen Hilfsnullwerten X0', der vorbestimmten Größe Y und dem Winkel α.

2. Verfahren nach Anspruch 1, ferner umfassend folgenden Schritt:
axiales Ausrichten der Horizontalwalzen (12, 12') vor dem Erzielen der zweiten gegenseitigen Walzenberührung

3. Verfahren nach Anspruch 2, wobei der Schritt des axialen Ausrichtens der Horizontalwalzen (12, 12') folgende Unterschritte umfasst

Lösen eines axialen Befestigungssystems der oberen Horizontalwalze (12'), so dass letztere axial zu einer Walzenwechselseite hin bewegt werden kann;

axiales Bewegen der oberen Horizontalwalze (12') um einige Millimeter zur Walzenwechselseite hin; und

Bewegen der Vertikalwalze (14, 14'), die an der Walzenwechselseite angeordnet ist, zur Mitte des Gerüsts hin und dadurch Drücken der oberen Horizontalwalze (12') zur Mitte des Gerüsts hin, bis die Bewegung durch eine der Horizontalwalzen angehalten wird

4. . Verfahren nach irgendeinem der Ansprüche 1 bis 3, wobei die realen vertikalen Nullwerte X₀ wie folgt berechnet werden:

Revendications

1. Procédé de remise à zéro automatique d'une cage refouleuse universelle pour laminer un profilé en H présentant une âme et deux ailes, ladite cage refouleuse universelle comprenant :

un cylindre horizontal supérieur (12') et un cylindre horizontal inférieur (12), chacun desdits cylindres horizontaux (12, 12') comportant une surface de laminage cylindrique (16, 16') pour laminer l'âme, deux surfaces de laminage épaulées (18, 18') pour laminer les ailes et deux flancs de laminage coniques (20, 20'), où α correspond à l'angle entre une génératrice de ladite surface de laminage cylindrique et une génératrice desdits flancs de laminage coniques ; et

un premier cylindre vertical (14) et un deuxième cylindre vertical (14'), chacun desdits cylindres verticaux comportant une surface de laminage conique supérieure (22, 22') coopérant avec l'un desdits flancs de laminage coniques (20') dudit cylindre horizontal supérieur (12') et une surface de laminage conique inférieure (24, 24') coopérant avec l'un desdits flancs de laminage coniques (20) dudit cylindre horizontal inférieur (12) pour laminer les ailes ; ledit procédé comprenant les étapes suivantes :

espacer l'un de l'autre lesdits cylindres verticaux (14, 14') horizontalement de manière à ne pas faire obstacle à un mouvement vertical desdits cylindres horizontaux (12, 12');

ajuster verticalement ledit cylindre horizontal inférieur (12') dans une position zéro prédéfinie ;

obtenir un premier kissing de cylindres en amenant ledit cylindre horizontal supérieur (12') en contact avec ledit cylindre horizontal inférieur (12) et en le pressant au moyen d'une pression de laminage contre ce dernier ;

enregistrer les positions dudit cylindre horizontal inférieur (12) et dudit cylindre horizontal supérieur (12') durant ledit premier kissing de cylindres en tant que des indices zéro pour lesdits cylindres horizontaux ;

espacer l'un de l'autre ledit cylindre horizontal inférieur (12) et ledit cylindre horizontal supérieur (12') de manière symétrique autour de la ligne de passage de ladite cage de façon à définir un écart d'une magnitude Y prédéterminée entre lesdits deux cylindres horizontaux, dans lequel ladite magnitude Y prédéterminée est choisie de telle sorte que lesdits cylindres verticaux (14, 14') peuvent toucher lesdits flancs coniques (20, 20') desdits cylindres horizontaux (12, 12');

obtenir un deuxième kissing de cylindres en pressant lesdits cylindres verticaux (14, 14') au moyen d'une pression de laminage contre lesdits flancs coniques (20, 20') desdits cylindres horizontaux (12, 12') ;

enregistrer les positions desdits cylindres verticaux (14, 14') durant ledit deuxième kissing de cylindres en tant que des indices zéro auxiliaires X0' pour lesdits cylindres verticaux ; et

calculer des indices zéro réels X0 pour lesdits cylindres verticaux (14, 14') en fonction desdits indices zéro verticaux auxiliaires X0', de ladite magnitude Y prédéterminée et dudit angle α

2. Procédé selon la revendication 1, comprenant en outre l'étape consistant à :

aligner de manière axiale lesdits cylindres horizontaux (12, 12') préalablement à une obtention dudit deuxième kissing de cylindres

3. Procédé selon la revendication 2, dans lequel ladite étape consistant à aligner de manière axiale lesdits cylindres horizontaux (12, 12') comprend les sous-étapes consistant à

déverrouiller un système de fixation axiale dudit cylindre horizontal supérieur (12'), de telle sorte que ce dernier peut être déplacé de manière axiale en direction d'un côté de changement de cylindre ;

déplacer de manière axiale ledit cylindre horizontal supérieur (12') de quelques millimètres en direction dudit côté de changement de cylindre ; et

déplacer le cylindre vertical (14, 14') situé dudit côté de changement de cylindre en direction du centre de ladite cage et pousser de ce fait ledit cylindre horizontal supérieur (12') en direction du centre de ladite cage jusqu'à ce que ledit mouvement soit arrêté par l'un ou l'autre desdits cylindres horizontaux.

4. Procédé selon l'une quelconque des revendications 1 à 3, dans lequel lesdits indices zéro verticaux réels X₀ sont calculés comme suit :

Drawing