Device to park a dummy bar downstream from the extraction and straightener group

Description

[0001] This invention concerns a parking device for a dummy bar according to the preamble of ,Claim 1.

[0002] To be more exact, the invention concerns a structure that swings between two positions, the first position being used to park the dummy bar during its phase of rest, whereas the second position is employed to support and guide the dummy bar during the phase of its initial insertion and also during the phase of starting a continuous billet (hereafter called "billet").

[0003] In the art of continuous casting the molten metal is conveyed in a wheeled ladle or by a crane to an ingot mould having an open bottom and suitable shape and located above the casting line.

[0004] The ingot mould receives the molten metal from the ladle through a pre-heated tundish and discharges the metal downwards through its open bottom in a partly solidified continuous flow of a pre-set section; this flow becomes gradually solidified on the casting line with the help of suitable cooling means located in the first part of the casting line.

[0005] It is necessary to close the open bottom of the ingot mould momentarily before beginning the casting so as to prevent a disorderly flow of the metal.

[0006] The open bottom of the ingot mould is closed by means of a dummy bar, which is inserted by a group of entraining rollers into the open bottom of the ingot mould, and any gap created between the dummy bar and the open bottom is sealed with suitable refractory material.

[0007] The first part of the metal poured into the ingot mould thus closed is left to solidify partially so as to become united to the head of the dummy bar.

[0008] Following on the filling of the ingot mould and its oscillation to hinder the formation of a crust of metal on its inner walls, the entraining rollers are actuated and arranged to pull the dummy bar and withdraw the billet connected to the end of the bar.

[0009] The dummy bar is detached from the billet thereafter and is parked in a suitable position near the extraction group and discharge line, along which the cast metal continues to travel for the rolling processes which follow thereafter.

[0010] The dummy bar, now having a new head, is taken once again from its parking device at the beginning of the next casting and the foregoing procedure to start the billet is followed once more.

[0011] Known dummy bars are substantially of three kinds: rigid bow-shaped dummy bars, semi-rigid bow-shaped dummy bars consisting of a number of articulated segments and flexible chain-type dummy bars.

[0012] The known systems to park rigid dummy bars or semi-rigid dummy bars in segments require a fixed support structure which is shaped like a bow, lies on the vertical plane of the casting line, stretches upwards from the extraction group and ends at a point having a height not less than the height of the ingot mould.

[0013] Patents US 3,930,533 (Rokop), US 3,433,287 (Greenberger) and US 3,344,844 (Reinfeld and others), which describe systems for parking dummy bars of this type, reveal some problems relating to the bulky construction, heavy weight and unsatisfactory layout of such fixed bow-shaped structures.

[0014] Patent US 3,682,233 (Rokop and others) claims a system to park flexible dummy bars which consists of a substantially upright fixed structure with a horizontal tract, the structure being located above the extraction group and casting line, a secondary entraining group being lodged in the horizontal tract so as to move the dummy bar within the bearing structure.

[0015] Notwithstanding the advantages offered by this system by way of a lesser bulk than in the above known systems, yet this system still takes up a great deal of space and is only fit for flexible dummy bars.

[0016] Indeed, the structure proposed in this patent stretches vertically above the ingot mould and takes up much useful space both near the extraction group and near the upper part of the casting plant.

[0017] DE-B2-2.714.338 is also known and discloses a rotatable structure which has two positions of cooperation with the dummy bar and also has means to pull the dummy bar. In this invention the rotatable structure is always located in correspondence with the casting line and is therefore always in a hot zone.

[0018] One problem common to the foregoing known parking systems lies in the fact that the new head of the dummy bar can be fitted only near the extraction group.

[0019] It is the purpose of our invention to embody a device to park dummy bars which swings between a raised position of rest and a lower usage position and which enables a new head to be fitted to the dummy bar during its phase of rest in a raised position far from the extraction group.

[0020] Moreover, the parking device of the invention takes up less space than known parking devices and has a lighter and more economical structure.

[0021] Another advantage is the free space created near the extraction group and discharge line during casting; this space can be employed for other more useful purposes.

[0022] Copending application for a European patent EP 82 830 115.0 in the name of the present applicant has the purpose of providing a parking device which can be raised and thus be moved away from hot zones but which is located upstream from an extraction and straightener group.

[0023] Instead the present invention has the purpose of providing a device of the type described above but located downstream from an extraction and straightener group, the device however permitting space to be saved just the same and also permitting the foregoing method of working with a position of rest outside the hot zone.

[0024] The solution of the problem of the invention is characterized by the characterizing features of Claim 1.

[0025] In a preferred embodiment of the invention the support structure consists of a cradle structure with a substantially bow-shaped profile and with a U-shaped section, whereby the cradle structure comprises a tubular element through which the rotation shaft passes and which is solidly fixed to the upper part of the two vertical sides of such structure, and whereby the cradle structure includes one or more integral levers stretching outwards and radially in relation to the tubular element and cooperating at their end with oscillator means anchored to the fixed structure of the machine on which the cradle structure pivots, and whereby the cradle structure in its turn bears means to pull and clamp the dummy bar which are able to effect any displacements of the dummy bar and the clamping thereof during the phase of rest.

[0026] The pulling of the dummy bar along the casting line and the loading thereof on the supporting cradle structure are carried out advantageously by the group which extracts the continuous billet.

[0027] We shall describe hereinafter a preferred embodiment of this invention as a non-restrictive example and shall refer to the attached figures, in which:

Fig. 1 gives a side view of the continuous casting machine with the cradle structure to park the dummy bar according to the invention;

Fig. 2 gives a view in the direction of the arrow C of Fig. 1 and shows only the cradle structure in its horizontal position where such structure is shown in Fig. 1 with lines of dashes in its position of rest;

Fig. 3 shows the tail of the dummy bar.

[0028] In the figures the same parts or parts having the same functions bear the same reference numbers.

[0029] In Figs. 1 and 2, a device 10 which parks a dummy bar 11 is located downstream from and above a group 12 that extracts and straightens an actual billet or continuous billet 13 in a continuous casting machine consisting of a ladle 14, tundish 15 and an ingot mould 16 having an open bottom and positioned on a casting line 17 equipped with rollers 18 and with a curved guide 118, the line 17 having in its first tract a cooling chamber 19, whereby there could be an oscillator group which acts on the ingot mould 16.

[0030] Downstream from the group 12 that extracts and straightens the billet is positioned a roller discharge table 20 on which the billet runs after the dummy bar 11 has been detached with known unfastening means generically indicated with 112.

[0031] In the example shown the group that unfastens the dummy bar 11 is part of the extraction and straightener group 12 and acts so that the head of the dummy bar anchored to the actual billet 13, when unfastened, is separated from the dummy bar 11, which goes without its head onto the parking device 10 and lets the actual billet run along the roller discharge table 20 for the processing phases thereafter.

[0032] The parking device 10, shown in Figs. 1 and 2 and being the purpose of our invention, consists of a swinging support structure 21 having a cradle-shaped structure 121 with a substantially bow-shaped bottom equipped with a plurality of idler rollers 22 and with two upright sides 221 connected together at their lower end with crosswise elements (not shown here), a crosswise tubular element 321 being envisaged as being anchored at its ends to the upright sides 221 in their upper part. Thus the cradle structure 121 has a substantially U-shaped section.

[0033] The tubular element 321 has at its ends two levers 421 which stretch out radially in relation to the tubular element 321 so as to form a fork together with the tubular element 321.

[0034] The levers 421 are preferably tilted in relation to the upper edge of the upright sides 221.

[0035] The two sides 221, tubular element 321 and two levers 421 form the unitary cradle structure 121. Such cradle structure 121 is arranged rotatably on the bearing structure 22 of the machine at a point above the discharge line 20 and just downstream from the extraction and straightener group 12.

[0036] Such anchorage point consists of a pivot 122 on which the tubular element 321 of the cradle 121 rotates. Figs. 1 and 2 show a preferred but not restrictive embodiment of oscillator means 24 which actuate the rotation of the cradle structure 21 between a horizontal raised position of rest shown with lines of dashes and another sloped working position in which the end B of the cradle structure lies in correspondence with the outlet of the extraction and straightener group 12.

[0037] In this example the oscillator means 24 consist of a hydraulic or pneumatic jack 124 anchored at one end to the bearing structure 22 of the machine by a suitable support 222, while the stem 224 of the jack 124 is pivoted at 322 on a crosswise shaft 425 solidly fixed at its ends to the free end of each of the levers 421, so that the stem 224 can actuate the rotation of the cradle structure 121 around the pivot 122.

[0038] According to the invention the cradle structure 121 also comprises means 25 suitable for pulling and clamping the dummy bar 11 on the cradle structure 121.

[0039] Such pulling and clamping means 25 only start working when the dummy bar 11 is out of the reach of the extraction and straightener group 12, and serve to pull the dummy bar 11 and hinder the return thereof, after its head 111 has been detached, to the extraction and straightener group 12.

[0040] In this example the pulling and clamping means 25 comprise a jack 125 pivoted at one end at 225 on the cradle structure 121; this jack 125 cooperates with an arm 325 swinging at 326 on a shaft 426 anchored at its ends to two supports 525 which are an integral part of the cradle structure 121.

[0041] Such cooperation between the swinging arm 325 and jack 125 takes place through the articulation of the stem 251 at a point 252 located between a free end 327 of the arm 325 and the point of rotation 326 of the arm 325.

[0042] The free end 327 of the arm 325 is a hook- wise end and can lodge itself in an upright notch 211 located lengthwise in the tail 411 of the dummy bar 11 and can cooperate with a pin 311 located crosswise within the notch 211, as shown in Fig. 3.

[0043] The pulling means 25 are required to provide a thrust only in an upward direction and are inactive when the dummy bar 11 has to be inserted in the extraction and straightener group 12, to which the dummy bar 11 descends, taking with it the free end 327 of the swinging arm 325, from which it is detached automatically when the arm 325 reaches the stop at the lower end of its run.

[0044] It is best to emphasise that the clamping action of the means 25 is only necessary when the cradle structure 121 is in its inclined position since in the position of rest the dummy bar 11 stays still within such structure, where the application of its head 111 is prepared in a raised working station near which the end B of the cradle structure 121 halts.

[0045] When the dummy bar 11 is to be inserted during the readying of the machine at the beginning of casting, the cradle structure 121, taking with it'the dummy bar 11 complete with a removable head 111, is driven by the oscillator means 24 so as to take up its working position.

[0046] The dummy bar 11 stays attached to the cradle structure 121 owing to the clamping action of the means 25.

[0047] When the working position is reached, the jack 125 is disactivated and enables the arm 325 to rotate clockwise under the action of the weight of the dummy bar 11, which inserts itself in the extraction and straightener group 12 and enters upon its field of work.

[0048] The group 19 pulls the dummy bar 11 along the casting line 17 until its head 111 is inserted into the bottom of the ingot mould 16.

[0049] When the first casting phase ends, the dummy bar 11, of which the tail has stayed during such phase between the entraining rollers 212 of the extraction and straightener group 12, is withdrawn and thrust along the cradle-wise parking structure 121, which is lying in its working position.

[0050] When the head 111 of the dummy bar 11 reaches the extraction rollers 212, a pin 311 provided in the tail 411 of the dummy bar 11 lies near the bottom dead centre of the hook- wise end 327 of the swinging arm 325, the end 327 being now in a raised and retracted position.

[0051] The jack 125 now starts working, rotates the arm 325 anticlockwise and forces the arm 325 to hook itself onto the pin 311 of the dummy bar 11 and to pull the dummy bar 11 upwards while its head 111 is still anchored to the billet 13.

[0052] When the head 111 reaches the means 112 that unfasten the head, the dummy bar 11 is freed in a known way and continues its path along the cradle structure 121 until the swinging arm 325 reaches its top dead centre, where the arm 325 is clamped by the jack 125 and at the same time hinders the return of the dummy bar 11 downwards.

[0053] The actual billet 13, instead, goes on moving along the roller discharge table 20.

[0054] The oscillator means 24 now start working and, by the actuation of the two-way jack 124, rotate the cradle structure 121 and therewith the dummy bar 11 into the raised parking position or position of rest, where a new head 111 is fitted and made ready for the next casting.

[0055] We have described herein a preferred embodiment of the invention, but further variants are possible within the scope of the claims.

[0056] The shape and constructional features of the swinging cradle structure 121 can be varied, and other kinds of actuation means can be envisaged for performing the action of the oscillator means 24 and pulling and clamping means 25, such other kinds of actuation means being able to cooperate with flexible dummy bars of the types having articulated segments or chains, the whole being possible for a person skilled in this field without departing thereby from the scope of the inventive idea of this invention as contained in the claims.

Claims

1. Device to park a dummy bar (11) in continuous casting machines with a casting line (17) which employs rollers (18), stretches between the ingot mould (16) and the substantially horizontal outlet and comprises:

- an extraction and straightener group (12) located at said outlet;

- a swinging support structure (21) for parking the dummy bar (11), the structure (21) being rotatably sustained at its upper side downstream from the extraction and straightener group (12) and having a raised position and a lowered position;

oscillator means (24) which carry out rotation of the support structure (21) between its raised position and lowered position;

- means (25) which pull and clamp the dummy bar (11) on the support structure (21) and are anchored to the same structure (21 );

- means for controlling and coordinating the actuation of the oscillator means (24) and of the means (25) which pull and clamp the dummy bar (11), the device being characterized by the fact that the swinging support structure (21) is located downstream from the extraction and straightener group (12), the raised position of the structure (21) being a position of rest whereas its lowered position is a working position, the structure (21) being shaped cradle-wise (121) with two upright sides (221) connected in their upper part by a tubular element (321) and in their lower part by a bottom element (22) equipped with rollers, the tubular element (321) being able to rotate about a pivot (122) sustained crosswise by the bearing structure (22) of the machine, such cradle-wise structure (121) comprising one or more actuation levers (421) which stretch out far from the axis of rotation of the cradle structure (121) and are anchored at their end to the outer surface of the tubular element (321).

2. Device as claimed in Claim 1, characterized by the fact that the swinging support structure (21) consists of a cradle structure (121) which has a substantially bow-shaped profile and U-shaped section and is pivoted at its upper side on the fixed bearing structure (22) of the casting machine.

3. Device as claimed in Claim 1 or 2, characterized by the fact that the actuation levers (421) are tilted in relation to the upper edges of the upright sides (221) of the cradle structure (121).

4. Device as claimed in Claim 1 and in one or another of the claims thereafter, characterized by the fact that the oscillator means (24) consist of a jack (124) pivoted at one end on the bearing structure (22) of the machine and having the free end of its stem (224) pivoting at (322) on a crosswise shaft (425) anchored at its ends to the free ends of the actuation levers (421).

5. Device as claimed in Claim 1 and in one or another of the claims thereafter, characterized by the fact that the pulling and clamping means (25) comprise a jack (125) pivoted at one end at (225) on the cradle structure (121), and by the fact that the stem (251) of the jack (125) is pivoted at an intermediate point on a swinging arm (325) pivoted at one end (326) on a crosswise shaft (426) anchored at its ends to two upright supports (525) solidly fixed to the cradle structure (121), the free end (327) of the swinging arm (325) following an arc tangential to the lengthwise axis of the cradle structure (121).

6. Device as claimed in Claims 1 and 5, characterized by the fact that the free end (327) of the swinging arm (325) comprises, in its edge opposite to the outer end (A) of the cradle structure (121), a hook-like profile which cooperates momentarily with a pin (311) positioned crosswise within a lengthwise groove (211) machined in the tail (411) of the dummy bar (11).

Ansprüche

1. Vorrichtung zum Parken eines Anfahrstückes (11) in Stranggießmaschinen mit einem Rollen (18) verwendenden Strang (17), der sich zwischen der Blockkokille (16) und dem wesentlich waagerechten Anzug erstreckt und der folgende Teile enthält:

- ein an dem genannten Anzug angeordnetes Abheb- und Richtaggregat (12);

-eine schwingende Halterungsstruktur (21) zum Parken des Anfahrstückes (11), wobei die Struktur (21) oben unterhalb des Abheb-und Richtaggregats (12) drehbar gestützt ist und eine gehobene Stellung und eine gesenkte Stellung aufweist;

-schwingende Mittel (24), die die Rotation der Halterungsstruktur (21) zwischen der gehobenen Stellung und der gesenkten Stellung durchführen;

- Mittel (25), die das Anfahrstück (11) auf der Halterungsstruktur (21) mitnehmen und blockieren und an der selben Struktur (21) befestigt sind;

-Mittel zur Kontrolle und Koordination der Betätigung der schwingenden Mittel (24) und der Mittel (25), die das Anfahrstück (11) mitnehmen und blockieren, wobei die Vorrichtung dadurch gekennzeichnet ist, daß die schwingende Halterungsstruktur unterhalb des Abheb- und Richtaggregats (12) angeordnet ist, wobei die gehobene Stellung der Struktur (21) eine Ruhestellung, während ihre gesenkte Stellung eine Arbeitsstellung ist und wobei die Struktur (21) als Wiege (121) mit zwei senkrechten Seiten (221) gebildet ist, die im oberen Teil einem röhrenförmigen Element (321) und im unteren Teil einem mit Rollen ausgerüsteten Grundelement (22) gemein sind, wobei das röhrenförmige Element (321) dazu fähig ist, sich um einen Zapfen (122) zu drehen, der von dem Tragwerk (22) der Maschine quer gestützt ist, wobei diese wiegenförmige Struktur (121) einen oder mehrere Betätigungshebel (421) enthält, die sich von der Rotationsachse der wiegenförmigne Struktur (121) vorbeugen und am Ende der äußeren Fläche des röhrenförmigen Elements (321) befestigt sind.

2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die schwingende Halterungsstruktur (21) aus einer wiegenförmigen Struktur (121) besteht, die ein wesentlich gebogenes Profil und einen U-förmigen Durchschnitt hat, und oben am festen Tragwerk (22) der Gießmaschine verzapft ist.

3. Vorrichtung nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Betätigungshebel (421) gegenüber den oberen Rändern der senkrechten Seiten (221) der wiegenförmigen Struktur (121) geneigt sind.

4. Vorrichtung nach Anspruch 1 und dem einen oder dem anderen der folgenden, dadurch gekennzeichnet, daß die schwingenden Mittel (24) aus einer Winde (124) bestehen, die an einem Ende auf dem Tragwerk (22) der Maschine verzapft ist und mit dem freien Ende des Schaftes (224) in (322) auf einer queren Welle (425) angezapft ist, die endend an den freien Enden der Betätigungshebel (421) befestigt ist.

5. Vorrichtung nach Anspruch 1 und dem einen oder dem anderen der folgenden, dadurch gekennzeichnet, daß die Mittel zum Mitnehmen und zum Blockieren (25) eine Winde (125) umfassen, die an einem Ende in (225) auf der wiegenförmigen Struktur (121) ihren Drehpunkt hat und daß der Schaft (251) der Winde (125) in einem Zwischenpunkt auf einem schwingenden Arm (325) angezapft ist, der an einem Ende (326) auf einer queren Welle (426) angezapft ist, die an ihrem Ende an zwei senkrechten Trägern (525) befestigt ist, die an der wiegenförmigen Struktur (121) fest befestigt ist, wobei das freie Ende (327) des schwingenden Armes (325) einem zur Längsachse der wiegenförmigen Struktur (121) tangentialen Bogen folgt.

6. Vorrichtung nach Anspruch 1 bis 5, dadurch gekennzeichnet, daß das freie Ende (327) des schwingenden Armes (325) an seinem dem äußeren Ende (A) der wiegenförmigen Struktur (121) gegenüberliegenden Ende ein Hakenprofil umfaßt, das zeitlich mit einem Zapfen (311) mitwirkt, der quer in einer Längsnut (211) angeordnet ist, die im Endteil (411) des Anfahrstückes (11) gezogen wird.

Revendications

1. Dispositif pour stocker un mannequin (11) dans des machines de coulée continue, munies d'une ligne de coulée (17), qui utilise des rouleaux (18), s'étend entre la lingotière (16) et la sortie pratiquement horitale et comprend:

- un groupe d'extraction et de dressage (12) situé à ladite sortie,

- une structure de support oscillante (21 ) poue le stockage du mannequin (1 1 la structure (21) étant soutenue de manière à pouvoir tourner à son côté supérieur, en aval du groupe d'extraction et de dressage (12) et ayant une position levée et une position abaissée,

- des moyens oscillateurs (24) qui effectuent la rotation de la structure de support (21) entre sa position levée et sa position abaissée,

- des moyens (25) qui tirent et enserrent le mannequin (11) sur la structure de support (21) et sont ancrés à cette même structure (21

- des moyens de commande et de coordination de l'actionnement des moyens oscillateurs (24) et des moyens (25), qui tirent et enserrent le mannequin (11), le dispositif étant caractérisé par le fait que la structure de support oscillante (21) est située en aval du groupe d'extraction (12), la position levée de la structure (21) étant une position de repos, tandis que sa positionabaissée est une position de travail, la structure (21) étant en forme de berceau (121) muni de deux côtés verticaux (221), reliés à leur partie supérieure par un élément tubulaire (321) et, à leur partie supérieure, par un élément de fond (22) équipé de rouleaux, l'élément tubulaire (321) étant capable de tourner autour d'un pivot (122) soutenu transversalement par la structure porteuse (22) de la machine, la structure en berceau (121) comprenant un ou plusieurs leviers d'actionnement (421) qui s'étendent loin de l'axe de rotation de la structure de berceau (121) et sont ancrés par leur extrémité à la surface extérieure de l'élément tubulaire (321

2. Dispositif selon la revendication 1, caractérisé par le fait que la structure de support oscillante (21) est formée d'une structure de berceau (121) qui a pratiquement un profil arqué et une section en U et a son pivot à son côté supérieur sur la structure porteuse fixe (22) de la machine de coulée.

3. Dispositif selon l'une des revendications 1 et 2, caractérisé par le fait que les leviers d'actionnement (421) sont inclinés relativement aux bords supérieurs des côtés supérieurs (221) de la structure de berceau (121).

4. Dispositif selon la revendication 1, et l'une ou l'autre des revendications suivantes, caractérisé par le fait que les moyens oscillateurs (24) sont formés d'un vérin (124) ayant son pivot à une extrémité sur la structure porteuse (22) de la machine et dont l'extrémité libre de la tige (224) pivote en (322) sur un arbre transversal (425) ancré par ses extrémités aux extrémités libres des leviers d'actionnement (421).

5. Dispositif selon la revendication 1, et l'une ou l'autre des revendications suivantes, caractérisé par le fait que les moyens de traction et d'enserrement (25) comprennent un vérin (125) ayant un pivot à une extrémité, en (225), sur la structure de berceau (121), et par le fait que la tige (251) du vérin (125) a son pivot en un point intermédiaire sur un bras oscillant (325) ayant son pivot à une extrémité (326) sur un arbre transversal (426) ancré par ses extrémités à deux supports verticaux (525) fixés solidement à la structure de berceau (121), l'extrémité libre (327) du bras oscillant (325) suivant un arc tangentiel à l'axe longitudinal de la structure de berceau (121).

6. Dispositif selon les revendications 1 et 5, caractérisé par le fait que l'extrémité libre (327) du bras oscillant (325) comprend, dans son bord opposé à l'extrémité extérieure (A) de la structure du berceau (121), un profil crochu qui coopère momentanément avec une goupille (311) placée transversalement à l'intérieur d'une gorge longitudinale (211) usinée dans la queue (411) du mannequin (11).

Drawing