DE3742155A1

DE3742155A1 - Method and apparatus for producing seamless tubes

Info

Publication number: DE3742155A1
Application number: DE19873742155
Authority: DE
Inventors: Alfred Ing Grad Lampe; Michael Dr Ing Graefe; Albrecht Dr Ing Eicken
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1987-12-10
Filing date: 1987-12-10
Publication date: 1989-06-22
Anticipated expiration: 2007-12-11
Also published as: DE3742155C2

Abstract

Published without abstract.

Description

State of the art

Der Stand der Technik betrifft sowohl das Stoßbankverfahren entsprechend DE 30 21 940 C2 als auch in geringerem Maße die verschiedenen Rohrkontiverfahren mit freilaufender oder ge steuerter Dornstangenbewegung.The prior art relates to both the push bench process according to DE 30 21 940 C2 as well as to a lesser extent various pipe continuous processes with free running or ge controlled mandrel rod movement.

Beiden Verfahren ist es gemeinsam, daß Rohrluppen auf langen zylindrischen Dornstangen zu Rohren ausgestreckt werden und die Verformung in hintereinander angeordneten Gerüsten mit ent sprechend kalibrierten Walzen bzw. Rollen durch die Reduktion von Durchmesser und Wanddicke der Rohrluppen erfolgt. Ein Ver gleich der Verfahrensunterschiede, aus denen sich Vor- und Nachteile ableiten lassen, ergibt folgendes Bild:It is common to both methods that long tube blanks cylindrical mandrel bars to be stretched into tubes and the Deformation in scaffolds arranged one behind the other with ent speaking calibrated rolls or rolls through the reduction of the diameter and wall thickness of the tube blanks. A ver equal to the procedural differences that make up the preliminary and Letting down the disadvantages gives the following picture:

A) Pipe length that can be produced

A 1) In the push bench procedure, the stretched out is The entire length of the tube on the mandrel bar; the until her reached max. Pipe length is 22.3 m at 23.0 m Length of mandrel.
A 2) In the continuous tube process, the tip of the tube overtakes when it stops stretch the mandrel rod tip more or less far Depends on the speed of the controlled mandrel pole. The max. Tube length is 36 m with 27 m mandrel length.

B) Drive systems

B 1) In the push bench process, the tube blank, its front End is formed into an abutment by a mandrel rod, the end face of which is supported on the abutment, driven by reducing stands arranged one behind the other ben, where three or four loose rollers Form caliber.
B 2) In the continuous tube process, the deformation takes place in six up to eight consecutively arranged rolling stands with one single drive, in which two rolls each have a caliber the.
The mandrel bar represents the pipe continuous process in Ge Contrary to the push bench procedure a braking, the Mate Rialfluss hinders element because of their speed usually lower than the material speed is.

C) Deformation conditions

C 1) In the push bench process, the combination of antrei results bender mandrel bar and loose running rollers very cheap Deformation conditions.
The mandrel bar speed is always greater than that Material speed. In the forming zones of the calibers the proportion of longitudinal tensile stress is high, the material width correspondingly small.
With high longitudinal tensile stresses, the radial stress decreases and thus the rolling force is considerably higher than that of draft-free Rollers. This gives the possibility of using very small roles high stretchability. It also has a favorable effect the number of three or four rolls that make up a caliber compared to two-roll calibers.
In the push bench process, this results in almost a pa parallel-epipedic deformation with a high shape efficiency.
C 2) In the continuous tube process, the driven rollers are with their drive pins made from one piece. The necessary roll width results from the tube blank diameter. The minimum dimensions of a continuous roller arise from constructive conditions. The calculation the rolling forces and moments to control the shatterproof unit always refers to the one included in the calculation existing roll diameter, d. that is, the necessary magnification At the same time, the diameter of the roller leads again an increase in forces and moments.
Due to the high roll costs, it is necessary to Diameter of new rollers 50 to 100 mm larger than that arithmetic diameter to choose a multiple To allow reworking of the rollers.
If you compare the same assumed deformation quantities the basic caliber diameter of bumper rolls and contours roll, it turns out that this is twice as much for the rolls are large or must be due to the rolling forces.
The unfavorable deformations that cause the high rolling forces The simplified conditions result from the following in comparison with the push bench method nega tive influences:
The mandrel speed is lower than the mate rial speed, it acts as a brake on the Ma material flow and increases the spread.
In the deformation zone of the calibers there are no significant longitudinal tensile stresses resulting from the external longitudinal tensile stress, which could reduce the spreading and the rolling force. The frictional forces occurring on the mandrel rod increase the rolling forces accordingly. The large roller diameters, together with the previously mentioned influencing variables, result in the fact that the resistance to deformation has values between 25-60 kg / mm 2 compared to 8-12 kg / mm 2 in the butt bank method.

D) Drive power

D 1) In modern shock bench systems, the impact force on the Mandrel bar 90-120 tons. With a max. Mandrel bars diameter of 170 mm and a mandrel bar speed speed of 6.6 m / s is an installed drive power of twice 1600 kW required, with two direct current motors drive the mandrel bar via pinion and rack ben.
D 2) With a comparable pipe contour line with controlled Mandrel bar and seven individually driven roll stands is the drive power installed on the scaffolding four times as large.
This is understandable if one describes the under C) different deformation conditions does. In terms of the performance share of Rohrkontistraße ent fall about 25% on the single drive effect, 25-30% are attributed to the braking effect of the mandrel bar, the remaining difference to the shock bench performance results from the different degrees of deformation efficiency. It is remarkable that the for the mandrel control in installed holding device, usually with one Rack and pinion drive equipped with DC motors stands out as the drive for a medium-sized push bench would be enough.
The holding force to be exerted on the mandrel bar is dependent depending on the plant size between 100 and 200 tons.

E) Aspect ratios

E 1) For the push bench described under D 1), the max. Ratio of pipe length / pipe section length 16: 1 when used of fifteen reducing stands.
Aspect ratios of this magnitude are necessary maneuverable when the pipe blanks after the conventional impact banking procedures, d. H. by means of a punch press and downstream Elongator are manufactured and thus in their length are limited.
With the conventional method, the max. Pipe lengths can only be produced in the thin wall area. With increasing pipe wall thickness reduces the aspect ratio and there with the producible pipe length. The newer and in the Proven methods according to DE 30 21 940 C2 er it allows to use pipe blankets three to four times longer than the tube blanks in the conventional process are.
This gives rise to the possibilities of stretching reduction in the production of thick-walled pipes by the Compensate for the use of longer tubes or the maxima le aspect ratio is generally considerably lower start and use less stretching frames, or also larger tube with the same impact force and drive power Establish dimensions by decreasing the cross section can be reduced accordingly in the stretching frames.
E 2) With pipe contours, aspect ratios of Max. 6.5: 1 on a road with eight roll stands enough. The aspect ratio is in newer systems nisse with consideration of the mandrel rod load only in the order of 3.5: 1 to 5.0: 1. Similar the aspect ratio is like the push bench procedure smaller in the manufacture of thick-walled pipes.
The aspect ratio possible with the push bench process of 16: 1 also indicates the favorable deformation conditions of the procedure.

F) Design of the caliber series

F 1) In the push bench process, the caliber series is formed different numbers of stretching frames puts. The calculation of the caliber series is based on ei designed a constant inner tube diameter.
This changes the emerging pipe outer diameters with the pipe wall thicknesses produced ( Figure B).
For the production of a specific mandrel bar minimum pipe wall thickness belonging to the knife, the max. Number of stretching frames used. For the production thicker tube walls are at the rear end of the caliber series he stretching frames removed or by appropriate scaffolding replaced for adjustment. The last scaffolding of a caliber rows can be adjusted to influence the wall thickness.
The pipe section remains for a certain one Mandrel bar diameter constant.
The stretching frames, which weigh between 1200 and 1800 kg are relatively easy to handle of a caliber series inserted into a scaffold bed. The The distances between the scaffolding are in a so-called Set plan established.
Usually only two are used in a push bench system different mandrel bar diameters used because of the conversion time from one diameter to another about eight Takes hours.
F 2) In the continuous tube process, the number of roll stands is the bil with a fixed distance from each other that, constant. In the known systems there are scaffolding numbers common between six and eight.
Pipe outside diameter and outside pipe diameter lead ben also constant for a caliber series. Difference Liche pipe wall thicknesses are determined by different mandrels gene diameter generated, including the Rohrluppenwand thicknesses can be adjusted accordingly. All mill stands are equipped with a roller adjustment. This is a requirement Lich, because of the reworking of the rollers Liche roll diameters arise, but also to correct wall changes in the calibres.
The calibration is not the same for the continuous tube process more difficult than with the push bench procedure. The right loading calculation of the roll speeds used in the push bench process omitted, requires great practical experience and a speaking know-how ahead. With the account procedures depending on the dimension program 1 to 3 different calibers rows used.

G) mandrel bar load

G 1) In the push bench process, the rods are attached with a be agreed minimum working temperature, the higher is chosen here, the thinner the tube manufactured measurement is. Because of the relatively low specific Rolling pressures are not particularly demanding on the Mandrel bar material and its surface quality posed.
G 2) In the continuous tube process, especially in cases with ge controlled mandrel bar speed is the mechanical one and thermal stress on the mandrel rods extremely high. The Durability of the mandrel bar surface is high from a briefly occurring, from the friction heat right resulting peak value of the mandrel surface temperature rature dependent.
At low mandrel speed and simultaneously The product is made of relatively large elongation speed, specific pressure and coefficient of friction the mandrel bar an order of magnitude at which the allowable Limit temperatures are exceeded quickly.
It is common practice to specify the coefficient of friction treatment of the mandrel rod surfaces, z. B. ver chrome and a lubrication technology, which the Apply and be the composition of the lubricant to bring it to the lowest possible value.
Contour mandrels are through material and processing cost significantly more than push rod mandrels.
In contrast to the push bench, there is a pipe continuous process process the possibility of mandrel bars with unusable Twist off the surface and use the appropriate surface tariff for the production of thick-walled pipes use. Most of the time with the tube continuous process lying surface damage is a diameter reduction when turning at least 12 mm required Lich.

H) Production quantities of the plants

H 1) Depending on the dimension program and Quantity distribution 150 000-350 000 tons of finished pipes per Year.
Investment costs and production quantities are in a favorable ratio.
H 2) For pipe systems, the corresponding values are between 500,000 and 950,000 tons of finished pipes per year.
The advantage of the high productivity of the cont falls when pipe manufacturing plant by today's standards required with significantly smaller production quantities will.
The investment costs of Rohrkontistraße are only in ge marked by the amount of production.

Der Verfahrensvergleich zeigt deutliche Vorteile für das Stoß bankverfahren, wenn man die Verformungsbedingungen, die zu in stallierende Leistung sowie die einfach zu beherrschende und sichere Verfahrenstechnik betrachtet.The process comparison shows clear advantages for the impact banking procedure, if one considers the deformation conditions that are too in stalling performance as well as the easy to control and considered safe process engineering.

Demgegenüber stehen Vorteile für das Rohrkontiverfahren, die die Herstellung größerer Rohrlängen, die Produktionskapazität, die Arbeitsweise mit konstantem Rohraustrittsdurchmesser und damit auch die Möglichkeit zur Weiterverwendung abgedrehter Dornstangen betreffen. In contrast, there are advantages for the continuous tube process, which the production of longer pipe lengths, the production capacity, the mode of operation with constant pipe outlet diameter and thus also the possibility of reusing wacky Affect mandrels.

Die Qualität der hergestellten Rohre dürfte bei beiden Verfah ren gleich gut sein. Als wesentlicher Nachteil des Stoßbankver fahrens ist die Arbeitsweise mit konstantem Rohrinnendurchmes ser zu nennen. Bei den heute üblichen Unterschieden zwischen den geforderten minimalen und maximalen Rohrwanddicken ergeben sich Rohrdurchmesserunterschiede von 35 bis 40 mm. Mit diesem Nachteil wird das der Stoßbank nachgeschaltete Maßwalzwerk oder Streckreduzierwalzwerk belastet.The quality of the pipes produced is likely to be high in both processes be equally good. As a major disadvantage of the shock bench driving is the way of working with a constant pipe inside diameter to call it. With the usual differences between today result in the required minimum and maximum pipe wall thicknesses pipe diameter differences of 35 to 40 mm. With this Disadvantage will be the sizing mill downstream of the impact bench or Stretch-reducing mill loaded.

Für einen Dornstangendurchmesser von z. B. 130 mm und Rohrwand dicken von 3.75 bis 18.0 mm ergeben sich Rohraußendurchmesser von 139.5 bis 168.0 mm. Mit einem Streckreduzierwalzwerk könn ten aus den Grenzabmessungen z. B. die Fertigrohrabmessungen 114.3 × 4.0 und 114.3 × 20.0 hergestellt werden, wobei im er sten Fall die Durchmesserreduktion 17%, im zweiten Fall 31% beträgt. Das Streckreduzierwalzwerk ist damit auf einen maxima len Anstichdurchmesser von 168 mm auszulegen, bei Herstellung der minimalen Wanddicke kommen die ersten sechs Gerüste nicht zum Eingriff.For a mandrel diameter of z. B. 130 mm and tube wall thicknesses of 3.75 to 18.0 mm result in an outer tube diameter from 139.5 to 168.0 mm. With a stretch-reducing mill ten from the limit dimensions z. B. the finished pipe dimensions 114.3 × 4.0 and 114.3 × 20.0 are produced, in which he in the first case the diameter reduction 17%, in the second case 31% is. The stretch-reducing mill is therefore at a maximum len piercing diameter of 168 mm to design during manufacture the first six scaffolds do not come to the minimum wall thickness for intervention.

Die Verfahrensweise, mit konstanten Dornstangendurchmessern zu arbeiten, ist bei dem konventionellen Stoßbankverfahren - wie bereits gesagt - eine Notwendigkeit, da die Umbauzeiten beim Wechsel auf einen anderen Dornstangendurchmesser ca. acht Arbeitsstunden betragen. Dies hat folgende Ursachen:The procedure, with constant mandrel bar diameters too is working with the conventional push bench method - how already said - a necessity because the conversion times at Change to a different mandrel bar diameter approx. Eight Hours worked. This has the following causes:

Bei der Übertragung der Stoßkraft steht das aus Schaftstange und Dornstange bestehende Stangensystem unter Längsdruck und muß gegen Ausknicken gesichert werden. Das Stangensystem er reicht bei modernen Anlagen eine Länge von ca. 50 m. When the impact force is transmitted, it is made of a shaft rod and mandrel bar existing bar system under longitudinal pressure and must be secured against buckling. The rod system he a length of approx. 50 m is sufficient for modern systems.

Die Schaftstange, die in einem auf der Antriebszahnstange be festigten Reiter eingeschraubt ist, und die Dornstange vor sich her und durch die Streckgerüste schiebt, hat den gleichen Durchmesser wie die Dornstange.The shaft rod, which is in a be on the drive rack fixed rider is screwed in, and the mandrel in front of it and pushes through the stretching frames has the same Diameter like the mandrel bar.

Beim Dimensionswechsel sind alle Führungselemente und die Schaftstange mit dem Zahnstangenreiter zu wechseln.When changing dimensions, all the guide elements and the To change the shaft rod with the rack rider.

Bisher wurde offenbar noch keine Möglichkeit gefunden, das Stangenführungssystem unter erträglichem konstruktiven Aufwand für beliebige Dornstangendurchmesser anstellbar zu machen. So far, apparently, no way has been found that Bar guidance system with tolerable design effort to make it adjustable for any mandrel bar diameter.

Description of the invention and process criteria

Die nachfolgend beschriebene Erfindung stellt sich die Aufgabe, ein Rohrherstellungsverfahren mit den entsprechenden Vorrich tungen zu schaffen, das durch die folgenden gleichzeitig vor handenen Eigenschaften wesentliche Vorteile gegenüber anderen bekannten Verfahren aufweist.The object of the invention described below is to a pipe manufacturing process with the appropriate Vorrich to achieve this by the following at the same time existing properties have significant advantages over others known method.

1. Favorable deformation conditions with a correspondingly low one Power consumption;
2. simple process engineering;
3. Safe manufacture of thin-walled pipes with tolerances that meet today's high demands;
4. Processing of difficult to form steels;
5. low tool costs due to reworking of the tools;
6. high flexibility due to quick dimension changes;
7. low investment costs;
8. small space requirement.

Bei dieser Aufgabenstellung sind die unter Punkt 1-4 genann ten Bedingungen prinzipiell bei der Anwendung des Stoßbankver fahrens entsprechend DE 30 21 940 C2 realisierbar. Das vorge schlagene neue Verfahren benutzt das obige Verfahren insoweit, daß die Umformung einer Rohrluppe zum Rohr mittels einer ange triebenen Dornstange erfolgt, die die Rohrluppe durch Streckge rüste mit lose laufenden Rollen treibt, wobei die Streckgerüste in einem Gerüstbett gelagert sind. These tasks are listed under points 1-4 conditions in principle when using the push bench system driving according to DE 30 21 940 C2 realizable. The featured proposed new method uses the above method in so far that the forming of a tube blank to the tube by means of a driven mandrel rod, which the tube blank by Stregege set up with loose rollers, the stretching frames are stored in a scaffold bed.

Im Gegensatz zum bekannten Verfahren wird die Dornstange nicht durch Stoßen, sondern durch Ziehen angetrieben.In contrast to the known method, the mandrel bar is not driven by pushing but by pulling.

Damit entfallen alle bisherigen Einrichtungen zur Dorn- und Schaftstangenführung, die den Zweck hatten, das bis zu 50 m lange und unter Längsdruck stehende Stangensystem am Ausknicken zu hindern.This eliminates all previous facilities for mandrel and Shaft rod guide, which had the purpose that up to 50 m long and under longitudinal pressure bar system at the buckling to prevent.

Es wird somit möglich, ohne den zeitraubenden Umbau eines Stan genführungssystems, beliebige Dornstangendurchmesser einzu setzen.This makes it possible without the time-consuming modification of a Stan guide system to insert any mandrel bar diameter put.

Die bisher beim Stoßbankverfahren notwendige Arbeitsweise, Roh re mit konstantem Innendurchmesser und einem Wanddicken-abhän gigen Außendurchmesser herzustellen, ist naturgemäß weiterhin möglich (Bild B).The method of working previously required for the push bench process, producing tubes with a constant inside diameter and an outside diameter depending on the wall thickness, is of course still possible ( Figure B).

Die Erfindung schlägt vor, die beim Rohrkontiverfahren übliche Arbeitsweise, wobei Rohre mit konstantem Außendurchmesser und einem Wanddicken-abhängigen Innendurchmesser hergestellt wer den, zu verwenden oder die beiden Arbeitsweisen sinnvoll zu kombinieren.The invention proposes the usual in the continuous tube process Working method, whereby tubes with constant outer diameter and a wall thickness-dependent inner diameter who manufactured to use the or the two ways of working combine.

Beim Rohrkontiverfahren wird eine Kaliberreihe nach einem Nenn durchmesser benannt, der dem Rohraustrittsdurchmesser ent spricht. Weiterhin ist diese Kaliberreihe durch einen zugehöri gen konstanten Rohrluppendurchmesser und die Anzahl der Walzge rüste definiert. In the continuous tube process, a caliber series is named named diameter that corresponds to the pipe outlet diameter speaks. Furthermore, this caliber series is associated with one constant tube diameter and the number of rolls set up.

Die Anzahl der zugehörigen Dornstangendurchmesser entspricht der Anzahl der herzustellenden Wanddicken, soweit nicht benach barte Wanddicken durch Walzenanstellung mit dem gleichen Dorn stangendurchmesser gefertigt werden können.The number of associated mandrel bar diameters corresponds the number of wall thicknesses to be produced, unless adjacent beard wall thicknesses by roller adjustment with the same mandrel rod diameter can be manufactured.

Beim konventionellen Stoßbankverfahren entspricht der Nenn durchmesser dem Dornstangendurchmesser. Die Anzahl der Kaliber reihen wird bei den Rohrkontiverfahren durch die hohen Kosten für entsprechende Gerüst- oder auch Walzensätze auf normaler weise zwei Reihen begrenzt, deren Nenndurchmesserabstand rela tiv groß ist.In the conventional push bench method, the nominal corresponds diameter of the mandrel bar diameter. The number of calibers In the tube continuous process is ranked by the high costs for corresponding stand or roller sets on normal wise limited two rows, the nominal diameter distance rela tiv is large.

Beim Rohrkontiverfahren können Dornstangen, deren Oberflächen Beschädigungen, z. B. Härterisse aufweisen, auf einen kleineren Durchmesser abgedreht und nach entsprechender Vergütung und Oberflächenbehandlung zur Herstellung dickerer Rohrwände wei terverwendet werden. Hierbei ergibt sich ein Wanddickensprung von mindestens sechs Millimeter.In the continuous tube process, mandrel bars, their surfaces Damage, e.g. B. hardness cracks, to a smaller one Diameter turned and after appropriate remuneration and Surface treatment for the production of thicker pipe walls white be used. This results in a change in wall thickness of at least six millimeters.

Eine Weiterverwendung der Dornstangen in einer kleineren Kali berreihe erfordert ein beträchtliches Abdrehmaß.A further use of the mandrel bars in a smaller potash Series requires a considerable degree of calibration.

Bei der Anwendung der Arbeitsweise mit konstantem Rohraußen durchmesser im Rahmen des beschriebenen Verfahrens ergeben sich wesentlich günstigere Bedingungen als im Rahmen des Rohrkonti verfahrens.When using the working method with constant pipe outer diameter in the context of the described method result much more favorable conditions than in the context of the Rohrkonti procedure.

So können Kaliberreihen mit unterschiedlichen Anzahlen von Streckgerüsten gebildet werden. Aufgrund der geringen Gerüst gewichte ist die Anzahl der Nennkaliber keine wesentliche Ko stenfrage. So caliber series with different numbers of Stretching frames are formed. Because of the small scaffold weights, the number of nominal calibers is not a significant factor most question.

Die in die Streckgerüste eingebauten Rollen, die auf bestimmte Kalibermaße bearbeitet sind, erreichen eine hohe Lebensdauer, indem ein nicht mehr maßhaltiges Kaliber auf das nächstgrößere Kalibermaß nachbearbeitet wird. Die Rollen können dabei im ein gebauten Zustand auf einer speziellen Kaliberbearbeitungsma schine nachgeschnitten werden. Die Gerüste wandern bei dieser Nachbearbeitung innerhalb einer Kaliberreihe vom letzten auf den ersten Platz.The rollers built into the stretching frames, which are specific Caliber dimensions are processed, achieve a long service life, by a caliber that is no longer true to size to the next largest Caliber dimension is reworked. The roles can be in one built state on a special caliber machining be cut again. The scaffolding hikes with this Post-processing within a caliber series from the last one up the first place.

Das beschriebene neue Verfahren ermöglicht eine Anzahl von sinnvollen Variationen bei einer entsprechenden Kombination von Kaliberreihen und Dornstangendurchmessern.The new method described enables a number of reasonable variations with a corresponding combination of Caliber series and mandrel bar diameters.

Zum Beispiel (Bild A):For example ( picture A):

a) A caliber series with a certain nominal diameter (168) is formed by 13 plug-in calibers and has one constant inlet diameter.
By reducing the number of scaffolds to 11, 10 and 8 Ge equip with appropriate adjustment of the final caliber three additional, e.g. B. each by 6 mm larger tread diameter.
If one assigns these four outlet diameters to three accordingly stepped mandrel diameter, so twelve different wall thicknesses exactly without roll adjustment be put. The input wall thicknesses are the depending adapted mandrel bar diameters. The distances the additional outlet diameter should expediently the reduction in diameter of a dimension or stretch reduction scaffold.
With a second corresponding caliber series with small Rem nominal diameter (162) creates the possibility unusable mandrel bars of the first caliber series use. The difference in diameter of the two nominal potashes About can be chosen so that a favorable calibration measure results.
In this way of working, certain stretching frames are in two rows in correspondingly different positions can be used.
b) Instead of a caliber series with four outlet diameters it is also conceivable to use several caliber series, whose nominal diameters correspond to those previously assumed. These caliber series then each correspond to one the inlet diameter and reach a larger one Extension than in case a).
The appropriate combination results from the product program of the user and also in coordination with the downstream finishing mill.

Zur weiteren Lösung der gestellten Aufgaben benutzt die Erfin dung das Verfahren nach DE 30 21 940 C2, bei dem die Rohrluppe keinen Boden, sondern nach dem Kümpelvorgang ein offenes und nur geringfügig im Durchmesser reduziertes Ende aufweist. Die vorhandene Öffnung gestattet es, die Dornstangenspitze so aus zubilden, daß sich der Dornstangendurchmesser in bewährter Wei se an dem reduzierten Ende der Rohrluppe abstützt, während ein Zapfen mit entsprechend kleinerem Durchmesser aus der Öffnung der Rohrluppe herausragt. The Erfin uses it to further solve the tasks the method according to DE 30 21 940 C2, in which the tube blank no soil, but an open and has only a slightly reduced diameter end. The Existing opening allows the mandrel rod tip to look like this to form that the mandrel diameter in proven Wei supports at the reduced end of the tube blank while a Pin with a correspondingly smaller diameter from the opening protrudes from the tube.

Der Zapfen ist mit einem Kuppelkopf versehen, der in das Kupp lungsgegenstück einer Zugstange eingelegt wird (Fig. 1). Mit tels der Zugstange werden Dornstange und Rohrluppe durch die Rollenkaliber gezogen.The pin is provided with a dome head, which is inserted into the coupling counterpart of a pull rod ( Fig. 1). With the help of the pull rod, the mandrel rod and tube blank are pulled through the roller calibers.

Zur Ausbildung des Dornstangenzapfens kann die Dornstange ent sprechend abgedreht oder stirnseitig mit einer Gewindebohrung versehen werden, in die der Zapfen eingeschraubt wird.The mandrel rod can be used to form the mandrel rod pin turned off or on the front with a threaded hole be provided, into which the pin is screwed.

Für das Verfahren ist es ohne Bedeutung, ob die Dornstange in eine Rohrluppe eingefahren wird, deren vorderes Ende durch axi ales Kümpeln angeformt wurde (Fig. 1) oder ob erst nach dem Einfahren radial, z. B. durch Kümpelzangen, eine Anformung er folgt (Fig. 1a), bei der praktisch auf den Zapfen gekümpelt wird.For the method it is irrelevant whether the mandrel rod is inserted into a tube blank, the front end of which was formed by axi ales Küummeln ( Fig. 1) or whether only radially, z. B. by Kümpelzangen, a molding he follows ( Fig. 1a), is practically trimmed on the pin.

Der Durchmesser der Zugstange, die bei größeren Abmessungen ein Rohr mit eingeschraubten Kupplungsteilen sein kann, ist mit Rücksicht auf das Durchgangsmaß des kleinsten eingesetzten Rol lenkalibers zu bestimmen.The diameter of the drawbar that is used for larger dimensions Tube with screwed coupling parts can be with Consideration of the passage size of the smallest Rol used to determine steering caliber.

Zum Antrieb der Zugstange kann sowohl die bisher verwendete Zahnstange mit den zugehörigen Elementen als auch eine An triebskette verwendet werden.Both can be used to drive the pull rod Rack with the associated elements as well as an on drive chain can be used.

Die Erfindung geht vorzugsweise von einer umlaufenden Zwei- Strangkette aus, deren beide Stränge durch verschiedenartig ausgebildete Traversen miteinander verbunden sind. The invention is preferably based on a rotating two Strand chain, the two strands of different trained trusses are interconnected.

Der Arbeitshub erfolgt in zwei Stufen, indem zwei zwischen den Kettensträngen angeordnete Ziehtraversen nacheinander zum Ein satz kommen.The working stroke takes place in two stages, with two between the Chain strands arranged one after the other for pulling in sentence come.

Bei dieser Arbeitsweise, bei der die Kettenlänge und der Ket tenradabstand gegenüber der einstufigen Arbeitsweise praktisch halbiert werden, ergeben sich die Bedingungen, daß die Übernah me der Zugkraft von der ersten auf die zweite Traverse weitge hend stoßfrei erfolgt und daß das Ausschwenken der ersten Tra verse im Umlenkpunkt des antreibenden Kettenrades kraftfrei er folgt, um Kantenpressungen zwischen den beim Ausschwenken auf einander gleitenden, kraftübertragenden Flächen zu vermeiden. Die zweite Bedingung kann nur erfüllt werden, wenn die Kraft übernahme durch die zweite Traverse erfolgt, bevor die erste Traverse aus ihrer geradlinigen Bewegung umgelenkt wird und wenn gleichzeitig die kraftübertragenden Flächen der ersten Traverse durch eine zusätzliche Vorwärtsbewegung der Zugstange, relativ zu Kettenbewegung, voneinander getrennt werden.In this way of working, in which the chain length and the ket Ten wheel spacing practical compared to the one-step mode of operation halved, the conditions arise that the takeover the tractive effort from the first to the second crossbar hend bumpless and that the pivoting of the first Tra verse at the point of deflection of the driving sprocket follows to edge pressures between when swinging out to avoid sliding, force-transmitting surfaces. The second condition can only be met if the force takeover by the second traverse takes place before the first Traverse is deflected out of its rectilinear movement and if at the same time the force-transmitting surfaces of the first Traverse through an additional forward movement of the drawbar, relative to chain movement.

Erfindungsgemäß werden die vorgegebenen Bedingungen durch die folgenden Maßnahmen erreicht:According to the predetermined conditions by achieved the following measures:

a) The pull rod holds at its front and near its rear end diameter reductions, which are designed so that abutments are formed, on which fork-shaped drivers, which are built into the traverse members, can be supported ( Fig. 2, 3, 4).
b) The fork-shaped driver, which must be changeable depending on the dimension, in a front given position.
The fork-shaped driver is in the second traverse attached to a slider that in the traverse between stops in the longitudinal direction slidably and the stroke of which is approx. 50 mm.
c) The crossbar distances are chosen so that the second crossbar swings into the horizontal trajectory while the first crossbar is still at a certain distance from its deflection point ( Fig. 4b).
The driving fork of the second crossbar is there when in their rear position without contact with the ent speaking abutment surface of the tie rod.
At this position, the distance between the forked Mit in the two trusses is approx. 20 mm larger than the Distance of the corresponding abutment surfaces of the tie rod.
d) During the further chain movement, a toggle lever system is effective, which moves the sliding piece mounted in the second crossbar by max. 50 mm shifts ( Fig. 4d, 5). Here, the play between the driver surfaces in the second crossmember is first reduced ( Fig. 4c) and subsequently the pull rod is rela tively shifted by approximately 30 mm to the first crossmember while the force is being transferred. The additional movement of the pull rod is canceled by appropriate control of the toggle lever system after the first traverse has been pivoted out. Here, the slide of the second traverse returns to its original position and is supported on corresponding stops on the traverse.
e) The toggle lever system is - as can be seen from Fig. 5 - with its free ends on the one hand articulated in the slider, on the other hand on the extended chain pin, while the knee joint is provided with a roller.
The track for the roller is on a cross track verse adjustable.

Für die Durchführung des Verfahrens sind Vorrichtungen erfor derlich, die die schnelle Umstellung der Anlage auf verschiede ne Dorn- und Zugstangendurchmesser und das Entkuppeln von Dorn- und Zugstange sowie das Auswerfen der Dornstange mit dem auf diesem ausgestreckten Rohr aus dem Kettenbereich betreffen.Devices are required to carry out the method the quick changeover of the system to different ones ne mandrel and tie rod diameter and the uncoupling of mandrel and pull rod as well as ejecting the mandrel rod with the this extended tube from the chain area.

Erfindungsgemäß werden Dorn- und Zugstange zwischen den beiden Kettensträngen auf der von den Streckgerüsten vorgegebenen Walzmitte geführt. Das Abtragen der Stangen erfolgt auf lose laufenden prismatischen Rollen, die in Traversen gelagert sind, wobei diese pendelnd zwischen den Kettensträngen an entspre chend verlängerten Kettenbolzen aufgehängt sind (Fig. 6).According to the invention, the mandrel and tie rod are guided between the two chain strands on the rolling center specified by the stretching stands. The rods are removed on loosely running prismatic rollers, which are mounted in trusses, which are suspended from the chain strings on appropriately extended chain bolts ( Fig. 6).

Zur Anpassung an verschiedene Stangendurchmesser wird die Pen delbewegung der Traversen benutzt, wobei ein entsprechender Pendelausschlag fixiert wird (Fig. 6, Schnitt B-B), während sich die Rollentraversen auf der oberen Kettenführungsbahn be wegen. Hierzu sind die Traversenwangen an der einen Seite als Stützrollenhebel ausgebildet, während die Wangen auf der ande ren Seite so ausgebildet sind, daß die Pendelbewegung gegenüber den Kettenlaschen auf das erforderliche Maß begrenzt werden kann (Fig. 6, Schnitt C-C). Die Rollen der Stützrollenhebel stützen sich auf einer höhenverstellbaren Führungsbahn ab (Fig. 6, Schnitt A-A). To adapt to different rod diameters, the pen movement of the crossbars is used, with a corresponding pendulum deflection being fixed ( FIG. 6, section BB) , while the roller crossbars are on the upper chain guide track. For this purpose, the truss cheeks are designed on one side as a support roller lever, while the cheeks on the other side are designed so that the pendulum movement relative to the link plates can be limited to the required extent ( Fig. 6, section CC) . The rollers of the support roller levers are supported on a height-adjustable guide track ( Fig. 6, section AA) .

Zum Ende des Arbeitshubes, bei dem die Kettengeschwindigkeit auf Null gebremst ist, befindet sich die zweite Zugtraverse vor dem Umlenkpunkt des angetriebenen Kettenrades (Fig. 4e). Beim Bremsvorgang bewegt sich das Stangensystem relativ zur Kette weiter, bis das hintere Widerlager der Eindrehung an dem gabel förmigen Mitnehmer der zweiten Zugtraverse zur Anlage kommt und durch diesen ebenfalls abgebremst wird (Fig. 4f). Die an die Zugstange gekuppelte Dornstange mit dem auf ihr ausgestreckten Rohr liegt auf den Rollentraversen zwischen den beiden Ketten strängen.At the end of the working stroke, when the chain speed is braked to zero, the second traverse is in front of the deflection point of the driven chain wheel ( Fig. 4e). During the braking process, the rod system continues to move relative to the chain until the rear abutment of the recess on the fork-shaped driver of the second traverse comes to rest and is also braked by it ( Fig. 4f). The mandrel rod coupled to the drawbar with the tube stretched out on it is stranded on the crossbeams between the two chains.

Zum Entkuppeln muß die Dornstange senkrecht angehoben und nach folgend seitlich über einen Kettenstrang auf einen Ablaufrost befördert werden.To uncouple the mandrel bar must be lifted vertically and afterwards following laterally over a chain strand onto a drain grate to get promoted.

Für diese Aufgabenstellung wird ein Zugstangen-betätigtes He belsystem vorgeschlagen, dessen schwenkbare Hebelarme mit lose laufenden prismatischen Rollen und einem Querblech mit Ablauf schräge versehen sind (Fig. 7). In der Ruhestellung befinden sich die Hebel in waagerechter Lage und können von den Zug- und Rollentraversen überfahren werden. Nach dem Stoppen der Ketten bewegung können die Hebelarme zwischen den Kettentraversen hochgeschwenkt werden. Nach einer Schwenkbewegung von ca. 45° beginnen die Rollen der Hebelarme das Rohr anzuheben. Mit die ser Hubbewegung wird der Dornstangenkupplungszapfen aus dem noch oben offenen Kupplungsteil gehoben.For this task, a tie rod-actuated He lever system is proposed, the pivotable lever arms are provided with loosely running prismatic rollers and a transverse plate with an inclined drain ( Fig. 7). In the rest position, the levers are in a horizontal position and can be run over by the traverse and roller crossbars. After stopping the chain movement, the lever arms can be swung up between the chain crossbars. After a swivel movement of approx. 45 °, the rollers of the lever arms begin to lift the pipe. With this lifting movement, the mandrel rod coupling pin is lifted out of the coupling part, which is still open at the top.

Gegen Ende der Schwenkbewegung greift das Querblech an der Rohrunterseite an. Towards the end of the swivel movement, the cross plate grips the Tube underside.

Die gegen die Waagerechte geneigte obere Kante des Querbleches bewirkt, daß neben der Hubbewegung auch eine Seitwärtsbewegung des Rohres stattfindet.The upper edge of the cross plate inclined towards the horizontal causes a sideways movement in addition to the lifting movement of the pipe takes place.

Bei senkrechter Hebelstellung bildet die Querblechkante eine Ablaufschräge von ca. 5° Neigung gegen die Waagerechte, über die das Rohr mit der innenliegenden Dornstange abläuft (Fig. 7, Schnitt A-A).When the lever is in a vertical position, the transverse sheet edge forms a slope of approx. 5 ° to the horizontal, over which the pipe with the internal mandrel rod runs ( Fig. 7, section AA) .

Zur Ausgestaltung der Erfindung sind weitere Einrichtungen er forderlich, die sich aus der Beschreibung zur Anlage (Bild 8) ergeben.To design the invention, other facilities are required, which result from the description of the system ( Figure 8).

Description and procedure

Ein durchgelochter Hohlblock wird durch einen Rollgang 1 zum Quertransport 2 transportiert und über den Quertransport zum Ankümpeln vor die Kümpeleinrichtung 3 gebracht. Von dem Lager rost 4 wird eine Dornstange in den Rollgang 5 übergeben und in den angekümpelten Hohlblock eingefädelt. Über den Quertrans port 6, der z. B. aus Schwedenhebeln gebildet sein kann, werden Dornstange und Hohlblock in den Rollgang 7 übergeben, wobei gleichzeitig der Kuppelkopf der Dornstange in das Kupplungs gegenstück der entsprechend positionierten Zugstange eingelegt wird. Falls mit einer Kümpelzange oder ähnlichem statt mit einer Kümpelpresse gearbeitet wird, kann dieser Vorgang auch entsprechend abgeändert werden. Die Zugstange ist in dem Streckbankbett 8 auf höhenanstellbaren prismatischen Rollen gelagert, wobei ihr hinteres Ende mit dem Kupplungsteil in den Rollgang 7 hineinragt, während ihr vorderes Ende in der ersten Zugtraverse der Antriebskette 9 gelagert ist. A perforated hollow block is transported through a roller table 1 to the transverse transport 2 and brought to the trowel device 3 via the transverse transport for trimming. A mandrel bar is transferred from the bearing grate 4 into the roller table 5 and threaded into the hollow block. Via the Quertrans port 6 , the z. B. can be formed from Sweden levers, mandrel rod and hollow block are passed into the roller table 7 , at the same time the coupling head of the mandrel rod is inserted into the coupling counterpart of the correspondingly positioned tie rod. If you are using a plier or similar instead of a dome press, this process can also be modified accordingly. The pull rod is mounted in the stretching bench bed 8 on height-adjustable prismatic rollers, its rear end with the coupling part protruding into the roller table 7 , while its front end is mounted in the first pull crossbar of the drive chain 9 .

Bei dieser Starkposition wird die Kette durch die Antriebe 10 in Bewegung gesetzt, wobei die Dornstange von der Zugstange durch die in das Streckbankbett 8 eingebauten Streckkaliber ge zogen wird und dabei der Hohlblock auf der Dornstange zum Rohr ausgestreckt wird. Am Ende des Ausstreckvorganges befindet sich die zweite Zugtraverse am Umlenkpunkt des antreibenden Ketten rades, das freie vordere Ende der Zugstange liegt auf dem Roll gang 11, während das hintere Ende der Zugstange noch in der zweiten Zugtraverse gelagert ist.In this strong position, the chain is set in motion by the drives 10 , the mandrel rod being pulled from the tie rod by the stretching calibers installed in the stretching bench bed 8 and the hollow block on the mandrel rod being stretched out to the tube. At the end of the stretching process, the second traverse is at the deflection point of the driving chain wheel, the free front end of the tie rod is on the roller gang 11 , while the rear end of the tie rod is still stored in the second traverse.

Die Dornstange mit dem ausgestreckten Rohr liegt auf den Rol lentraversen zwischen den Kettensträngen. Durch eine entspre chende Vorrichtung wird die Dornstange angehoben und damit ent kuppelt und nachfolgend quer über die Ablaufschrägen 12 zum Rollgang 13 transportiert. Das Trennen von Dornstange und Rohr erfolgt nachfolgend - wie von Stoßbankverfahren bekannt - durch ein Lösewalzwerk 14 und eine Ausziehvorrichtung 18, wonach das Rohr dem Nachwärmofen 20 und die Dornstange dem Lagerrost 4 zu geführt wird.The mandrel bar with the extended tube lies on the roll bars between the chain strands. By a corre sponding device, the mandrel rod is raised and thus ent coupled and subsequently transported across the run-off slopes 12 to the roller table 13 . The mandrel rod and tube are subsequently separated, as is known from the push bench method, by a release roller 14 and a pull-out device 18 , after which the tube is guided to the reheating furnace 20 and the mandrel rod to the storage grate 4 .

Für den Betrieb der Anlage sind mindestens zwei Zugstangen er forderlich.At least two tie rods are required to operate the system conducive.

Der Zugstangenumlauf erfolgt vom Rollgang 11 über einen Quer transport 21 über den Rollgang 22 auf den Quertransport 23. In den Rollgang 7 wird eine Zugstange übergeben, sobald das hinte re Ende der Dornstange den Rollgang freigibt. Die Zugstange wird mit Hilfe von höhenanstellbaren, angetriebenen Rollen, die zwischen den Streckkalibern an beliebigen freien Stellen in das Streckbankbett eingesetzt werden können, durch die Streckkali ber gegen einen Anschlag gefahren, während das Rohr mit Dorn stange aus dem Bereich der Kette ausgeworfen wird. The tie rod circulation takes place from the roller table 11 via a transverse transport 21 via the roller table 22 to the transverse transport 23 . In the roller table 7 , a pull rod is handed over as soon as the rear end of the mandrel rod releases the roller table. The pull rod is driven by means of height-adjustable, driven rollers, which can be inserted between the stretching calibers at any free positions in the stretching bench bed, through the stretching pot against a stop, while the tube with the mandrel rod is ejected from the area of the chain.

Durch eine nachfolgende Kettenbewegung wird die erste Zugtra verse in Startposition gebracht; hierbei greift der gabelförmi ge Mitnehmer hinter den Kuppelkopf der Zugstange. Durch die Kettenbewegung wird gleichzeitig die vorher benutzte Zugstange von der zweiten Kettentraverse freigegeben und kann über den Rollgang 11 in den Umlauf gebracht werden.A subsequent chain movement brings the first traverse to the start position; the fork-shaped driver engages behind the coupling head of the drawbar. Due to the chain movement, the previously used pull rod is released from the second chain cross member and can be brought into circulation via the roller table 11 .

Bevor der gabelförmige Mitnehmer der ersten Zugtraverse in die Zugstangenausnehmung einschwenkt, wird die Zugstange mittels einer Vorrichtung so gedreht, daß das Einlegen des Kuppelkopfes der Dornstange in das entsprechende Kupplungsteil der Zugstan ge gewährleistet ist.Before the fork-shaped driver of the first traverse into the Swiveling the pull rod recess, the pull rod is by means of a device rotated so that the insertion of the dome head the mandrel rod into the corresponding coupling part of the tension rod is guaranteed.

Claims

1.Procedure for the production of seamless tubes, in which an open tube blank is first provided at its front end by reducing its inside diameter with an abutment for the end face of a longitudinally driven mandrel bar, then by means of forward movement of the mandrel bar through stretching frames mounted one behind the other in a scaffold bed which three or four loosely running rollers form a caliber, driven through and thus reduced in their outer diameter and extended over the mandrel bar, characterized in that:

a) a certain, from calibrated Streckgerü most formed caliber series by a, as caliber nominal diameter pipe outlet diameter, an associated pipe blank inlet diameter and a certain number of stretching frames is defined, with different pipe wall thicknesses being generated by corresponding mandrel rod diameters and the pipe block wall thickness corresponding Mandrel bar diameters are adapted;
b) two or more calibers formed in the manner described have nominal caliber diameters, the difference in diameter depending on the caliber dimension is 4-8 mm, the difference on the diameter reduction expediently z. B. 3% of the downstream finishing mill is tuned;
c) correspondingly graduated mandrel rod diameter combined with the various nominal caliber diameters who who that different tube wall thicknesses arise, for. B. with three mandrel bar diameters and three caliber diameters, nine correspondingly stepped wall thicknesses, the minimum wall thicknesses being produced in the small caliber;
d) certain stretching frames in different caliber series according to b) can be used, since their caliber dimensions are identical and only the location number within the caliber series is changed;
e) a caliber series formed according to a) in addition to the caliber nominal diameter may have one or more additional, larger tread diameters by the number of stretching frames being reduced from case to case and diameter gradations corresponding to b) arise with the difference that the tube group input diameter for al le outlet diameter remains the same and the elongation is reduced compared to case b) with the larger outlet diameters ( Figure A);
f) the caliber series according to e) is assigned a similar series with a smaller caliber nominal diameter, the difference in diameter corresponding to a favorable calibration dimension for reworking the mandrel rod set used in the larger caliber ( Fig. A);
g) the calibers are cut to the next largest caliber after wear and move over time in the caliber series from the last to the first place.

2. The method according to claim 1, characterized in that

a) the deformation process causing the longitudinal movement of the mandrel bar by pulling, by releasably coupling the mandrel bar to a pull bar and pulling it through the stretching frames used in a scaffold bed and forming a row of calibers;
b) a coupling head, which is inserted in a correspondingly designed Ge counterpart at the rear end of the pull rod, is screwed into the end face of the mandrel rod ( FIG. 1) or the end face of a bolt turned on the mandrel rod ( FIG. 1a) and the diameter the coupling head is smaller than the inside diameter of the tube blank at its end which is reduced to form an abutment;
c) the working stroke and the tensile force required for the deformation are brought about by a rotating two-strand chain driven by DC motors, the two strands of which are connected to one another by means of crossbeams and two traverse members, the tensile members acting one after the other on the tie rod and the chain wheel spacing therewith corresponds to approximately half the working stroke;
d) fork-shaped drivers are installed in the traverse members, which engage in corresponding turns of the tie rod which are designed as abutments ( FIGS. 1-4);
e) the driving fork of the second traverse is attached to a slidably mounted in the crossbar between stops and the power take-over from the first to the second crossbar by an additional sliding piece movement relative to the chain movement, at the same time the pull rod relative to the first Zugtraver se so far is that the driving fork of the most traverse he at the deflection point of the driven chain wheel can swing out without edge pressure from the abutment of the tie rod ( Fig. 4);
f) the additional movement of the slider within the second traverse is effected by a toggle lever system ( Fig. 5), the knee joint provided with a roller is pulled by the chain movement on an ascending path, while the two free lever ends on the one hand on chains, on the other hand on the Slider are articulated;
g) the sliding piece displacement relative to the crossbar is approx. 50 mm, with approx. 20 mm being used to compensate for play and to be withdrawn after the first crossbar has been swung out by the toggle lever roller then having exceeded the highest point of the ascending path and over egg ne sloping railway returns to its original position.

3. Devices for carrying out the method according to claims 1 and 2, comprising a rack consisting of a scaffold bed and the stretching frames that can be used therein, with a rod system consisting of a mandrel bar and a pull rod, and a rotating two-strand drive chain, the strands of which are pulled by two - And a corresponding number of crossbeams are connected to each other and the required transport roller tables and transfer devices, characterized in that:

a) mandrel and tie rod are detachably coupled to each other ( Fig. 1), the tie rod is machined in two places in each case at its front and near its rear end so that abutments arise against which fork-shaped driver the between the Can support chain strands stored traverse and at the same time the rotation of the tie rod is prevented ( Fig. 3);
b) for removal and diameter-appropriate support of the pull rod or the stretched tube with the mandrel inside gela verse between the two chain strands traverses with loose rollers are swinging ( Fig. 6, section BB) , with a certain pendulum swing the altitude the support rollers determined and a required pendulum deflection is achieved in that a truss cheek is designed as a lever arm with a roller and the roller is supported on a height-adjustable guideway ( Fig. 6, section AA) , while the other truss cheek is designed so that the Pendulum movement of the traverse remains limited to the necessary size during the chain circulation ( Fig. 6, section CC) ;
c) Apparatus according to claim 3 for uncoupling the pull rod and mandrel rod and then ejecting the tube stretched on the mandrel rod, which after the end of the stretching process is mounted between the chain strands on the roll lentraversen, consisting of a lever system to be actuated via a pull rod ( Fig. 7), wherein the free lever arms of the levers mounted between the guideways of the chain supports are pivoted between the roller crossbeams in the direction of the pipe to be ejected, characterized in that the free lever arms are equipped with both loosely running prismatic rollers and with transverse plates and with a pivoting movement of the lever initiated by the pull rod, the tube is first lifted vertically by the rollers without substantial longitudinal forces, the pull rod and mandrel rod being uncoupled, with a progressive pivoting movement the transverse plates with an edge that is inclined with respect to the horizontal, the further A. Take over the pipe and, when the lever is in the vertical position, form a run-off slope with an inclination of approx. 5 ° to the horizontal, roll it over the pipe and mandrel bar.