FR2588201A1 - METHOD, INSTALLATION AND ROLLING TRAIN FOR MANUFACTURE OF SOLDER FREE TUBES - Google Patents

Abstract

A.PROCEDE, INSTALLATION AND LAMINATION TRAIN FOR THE MANUFACTURING OF WELDLESS TUBES. B. PROCESS CHARACTERIZED IN THAT THE STRETCHING OF THE HOLLOW BLOCK IS CARRIED OUT ONLY BY MEANS OF A TRANSVERSAL LAMINATION OPERATION 14, DIVIDED IN SEVERAL STEPS, IN A PERMANENT OPERATING REGIME AND SIMULTANEOUSLY ON THE SAME HOLLOW BLOCK, CONSTITUTED OF MULTIPLE INTERCHANGEABLE 22 TRANSVERSAL ROLLER CAGES CONTAINING SEVERAL OBLIQUE 21 CYLINDERS, THIS TRANSVERSE ROLLING TRAIN FEATURES A CHUCK ROD RETAINED IN AXIAL DIRECTION AND PENETTS INTO THE GAUGE OPENINGS OF THE CAGES 20 OF THE ROLLING TRAIN 14. METHOD, A PLANT AND A LAMINATION TRAIN FOR THE MANUFACTURING OF SEAMLESS TUBES.

Description

Process, installation and rolling line for the manufacture of tubes

seamless "

To make tubes without

  lasts, different manufacturing processes are used

  both the starting material available, the dimensions

  final quantities, the quantities to be manufactured by

  unit of time, quality requirements and other cri-

  analogous these processes are profoundly differentiated

  from each other. The various processes have, however,

  in common three main operating phases, namely; first, the perforation and thus the manufacture of a hollow block, second, the drawing of this hollow block, to form a tube blank, and third, the finishing rolling of the blank of tube to form the completed tube, which did

  more need while being divided into desired lengths.

  For the manufacture of the hollow block, it is used, besides the punching process with the press,

  particularly often the oblique rolling process.

  The finishing rolling of the tube blank to form the finished tube is almost always carried out by means of stretch-reduction or rolling mills,

  therefore by a process operating continuously. In con-

  sequence, the various processes for making tubes

  seamlessly differentiate themselves first and foremost and

  clearly by their second operational phase, that is,

  ie by stretching the hollow block to form

  the tube blank. This is why the differences

  Some processes are named after the second phase of operation.

In the case of laminate treatment

  mandrel, the hollow block is, after perforation, stretched most of the time in a second

  oblique cylinders because in the mandrel mill

  However, it is possible to achieve only a limited cross-sectional reduction. After the oblique roller mill and chuck mill processing, the wall thickness tolerance is reduced in two smoothing mills mounted one after the other at

  the point of allowing the tube blank to be

black finishing.

  In this process, it is therefore necessary for the stretching operation, after the perforation, of an oblique-roll mill, a mandrel mill and two smoothing mills, which is related to high costs of production. investment and at a large footprint. In

  because of the relative cross-sectional reduction

  Due to the high thermal load of the mandrel, the final lengths obtainable with the mandrel rolling method are relatively short, resulting in the production of a large number of unusable end pieces.

  and as a result a high proportion of waste.

  With the rolling method using the pusher bench, after the perforation - which is often done by means of a drilling press - is used most of the time for the drawing of the hollow block

  a rolling mill with oblique cylinders, it implements

  following the pusher bench itself, and following a

  mill to disengage the tube from the mandrel, as well as a disc

  positive extraction, in order to remove from the draft of the

  tube, the mandrel rod used with the pusher bench.

Also in this process, we have

  need in all four groups of relative devices

  expensive, and because of the long length of the pushchair, a lot of room. The proportion of waste here is also relatively high, since after the operation with the pusher bed, the bottom of the tube blank must be separated and discarded. The lengths of tube blanks remain - because of the limited lengths of mandrel rods - generally less than 20 meters, so that lengths of completed tubes that can not be

  only up to about 200 meters.

  In the case of the continuous tube rolling process for tubes, the perforation of the block is carried out in a piercing mill and the drawing on a mandrel rod is pushed inside the hollow block, in milling cages mounted on the following each other, with calibrated openings having a closed contour to a large extent. The closed form of

  openings of calibers and the contact on a large sur-

  the material to be laminated with the mandrel rod

  cold results in considerable heat loss.

  rable for the material subjected to rolling and a strong heating of the mandrel rod. In order to limit these two phenomena thanks to a short duration of contact,

  laminated with a high speed of passage.

  This requires strong driving powers. The large engines, so required, 'make it difficult to precisely adjust the speed of

  rotation, so that there are losses of

  ciency. With this process one needs, in addition, to the

  following the continuous train for tubes, additional devices

  to remove the mandrel rods from

  tubes. In addition, a continuous train, with its six to eight rolling mill stands - of heavy construction in 4. because of the great rolling pressures - powerful sound

  training, and an additional mill for the former

  traction with rotation of the mandrel rod,

  a particularly expensive and non-profitable installation

  for relatively low production quantities

and averages.

  In the case of the matrix shear rolling process in which the drawing of the hollow block takes place in an oblique-roll mill with rotating guide discs, the maximum cross-sectional reduction achievable is relatively small and wall thickness at the relatively small initial pass, so that it can

  be necessary to climb forward of the shear mill

  a second rolling mill with oblique cylinders.

  Because of the low stretching, it is also possible to obtain a relatively short tube preform length, with the drawbacks already described above.

rolling mill chuck.

  In addition, the mandrel rod must have its accelerated displacement, more than the material to be rolled, by the rolls at the beginning of rolling. Consequently, it must not exceed given dimensions, which also limits the lengths of the tube blanks. First of all, however, in the process

  matrix shear rolling, the outer surface

  of the material to be laminated is in great demand

  rotational guide discs, which can not be

  not all materials without damage. In addition, the guide discs are the cause of a need for increased power, and thus increased operating costs, which

  are further increased by the wear of the guide discs.

  The rolling mill process

  planetary oblique-cylinders to allow

  the greatest possible reduction in trans-

  versale in one pass. This results in strong

  rolling pressures, forms of heavy construction

  and large masses in rotation. To maintain

  controllable centrifugal forces, rotational speed

  must remain low, and at the same time imperatively the speed of operation, especially in the case of small diameters of tube blanks, it results

  very low flow rate of the rolled material. In addition,

  sound of the strong form transformation, it results in problems when producing thin walls

  of tube blanks. On the other hand, there are

  gripping problems when introducing the hollow block into the gauge aperture. In addition, it is difficult to obtain a determined outside diameter of the tube blank. Finally, there are difficulties resulting from the significant reduction in cross section in one place only, since the temperature of the rolled material rises strongly there, which can be

  very detrimental to the material used.

  With the exception of the planetary mill rolling mill process with oblique cylinders, the other manufacturing processes require, after drawing and before finishing rolling, for example in a

  rolling mill-reducer, an intermediate warming

  re and consequently an additional reheating furnace, which entails considerable investment and operating costs. Also a direct entry into the following rolling mill-finisher is not possible in the other processes. However, all the manufacturing processes have in common that they produce drafts of

  tubes with wall thickness tolerances -

  measured at different points around the tube blank - which are not satisfactory. Such irregularities are troublesome during finishing rolling

  and may still be observed on the completed tube.

  The invention also relates to a method for producing seamless tubes, according to

  which a hollow block, heated to the temperature of

  end-to-end perforation in the longitudinal direction, a mandrel rod inserted therein, is stretched without rotation

  in a tube blank, and this is

  laminated suite without intermediate warming so

to form a finished tube.

  Such a principle process is

  nude from German Offenlegungsschrift 2657823, where the hollow block is drawn by means of an oblique roller planetary mill to form the tube blank. In this process we do

  certainly the economy of the oven - always necessary other-

  - for intermediate heating and it is possible to have a direct inlet of the tube blank in the finishing rolling mill, but this rolling mill process with eylindres planetary mill

  obliques is affected by the drawbacks listed below.

  extra. The object of the invention is to provide a method, a rolling mill installation and a rolling mill, for the manufacture of seamless tubes,

  to improve the second main operational phase

  cipal, that is to say the stretching of the hollow block to form the tube blank; and that as well from the point of view of the quality of the blanks of tube as with regard to

the profitability.

This goal is achieved

  to the invention, by pre-empting that the stretching of the block

  only by means of a laminating operation.

  transversal swim, carried out by being divided into several

  stages, in continuous operation, simultaneously

on the same hollow block.

  According to the process according to the invention

  tion, the cross section reduction is not realized in one step and in one place

  of the material to be laminated, as in all

  Nine rolling mills, with oblique roll mills, but on the contrary in several stages with relatively small section reductions. The particularity of this division is that the various steps are performed simultaneously on the same hollow block, even though it is in different places thereof. It can not

  be completely different than for the system of

  permanently, that is, when the beginning of the

  the rolling mill is already finished and that the

  end of the material has not yet been shaped.

  In addition, the division of the drawing operation into relatively small steps and the simultaneous execution of these steps on the same hollow block must be carried out both in operation according to a transverse rolling method. Thus the process according to the invention resides in a combination of three characteristics,

  which together achieve the desired goal.

  Thanks to the division of the operation

  stretching process - and consequently relatively

  These steps result in a relatively small reduction in cross-sectional area, and thus step-by-step formation of the material.

  subjected to rolling. In addition, several steps take place

  still allow a large reduction in cross-sectional area; we can thus implement

  blocks of significant weight, from which can -

  to make extremely long tubes.

  Due to the risk of inflection of the mandrel rod and due to the thermal load

  chuck, it is actually not possible, when

  perforation with a piercing mill, making a hollow block of more than 12 meters long. Relatively large block weights

  therefore can only be achieved through thick

  relatively large wall of the hollow block.

  However, such a wall thickness presupposes that, during the drawing of the hollow block to form the tube blank, it is possible to achieve a reduction in cross section that is all the more important

  in correspondence, which can not - for the reasons

  the most different sounds - be obtained with the known methods, even by the successive assembly of several rolling mills. Section reductions and at the same time stretches of the material to be rolled into tube blanks of about 20 meters in the case of the rolling mill process, and about 42 meters in the case of the continuous rolling mill process, form the

upper limit.

  On the other hand, with the process according to the invention, it is possible to obtain much greater total section reductions and thus a total elongation of the rolling material corresponding to twelve times, and more, the initial length; which gives the possibility of obtaining lengths of blanks of tubes of 120 meters and more. From such a tube blank, it is possible, with the known finishing rolling processes, to obtain tube lengths of 1200 meters.

and more.

  Due to the division, in accordance with the invention, of the reduction of section in several stages, and the strong total reduction obtained as a result

  by stretching, there is no need, when perforating

  block in the piercing mill, to look for a

  particularly thin wall, and it is difficult to

  which are linked to a thin wall. Since the large section reduction during drawing is also carried out simultaneously on the same hollow block, so in a single rolling train, the machining time remains short and above all the loss of heat remains very low. In most known processes, the reduction of section takes place instead, not simultaneously, but in several different rolling mills mounted one after the other; then there is a lot of heat lost through transportation, chuck rod change and other operations. Since according to the process according to the invention, it is in

  the field of stretching a trans-

  versal, this also allows a very significant improvement

  the tolerance of wall thickness, particularly around the rim of the tube blank, which can not be

  obtained in the case of longitudinal rolling.

  It is advantageous to realize the opera-

  transverse rolling alternately in the two possible directions of rotation, preferably from step to step. The torsional force exerted on the material subjected to rolling is thus largely suppressed. The forming is then done with more care of the material. In addition, a line of cross lamination of the various sections of the material is produced.

  subjected to rolling, which allows close tolerances.

  Preferably, in the process

  According to the invention, stretching of the hollow block is carried out in greater stages on the inlet side than on the output side. This results in narrower rolling tolerances and avoids the difficulties that arise for a large reduction in section on thin walls of tube blanks. Due to the fact that the cross-sectional reduction is always smaller and goes to the exit side, the transverse rolling operation is progressively continued in a smoothing operation with barely noticeable section reduction. This results in a largely uniform distribution of the total drive power on all mill stands, and also the pairs of

  rotation are of approximately identical values.

  The invention also relates to a rolling installation for implementing the method according to the invention. This system is characterized in that a transverse rolling mill is arranged, forming a block assembly, directly following an obliquely rolling mill roll stand known per se, for the purpose of perforation, and directly to the machine. before a finishing mill, also known. As a result of one of the oblique cylinder mill stands for perforation, only one installation is required for drawing, and not

  several rolling mills and devices as in most

  part of known installations. We can do without

  auxiliary devices, such as, for example,

  rotation devices of the mandrel shank, lami-

  black to clear the mandrel rods and others.

  In addition, an oven is saved for heating after the stretching operation. In addition, the tube blank thus manufactured can enter

  directly in the finishing rolling train,

  calibrated by a calibrating or reducing-reducing mill, which can be mounted directly afterwards and at a

  very short distance from the transverse rolling train.

  Independent exit of rolled products after labeling

rabies is not necessary.

  These experiences were certainly already

  obtained with an installation equipped with a flat rolling mill

  oblique cylinders, but in which

  come the disadvantages indicated above, including problems during the production of thin walls

of tube blanks.

The installation according to the invention

  In particular, its transverse rolling mill is able to provide, during drawing, a large reduction in cross section with close tolerances; This makes it possible to laminate, thanks to heat, large blocks of weight to form very long and thin-walled tubes. It is recommended then to equip the three groups of the installation of three-cylinder caliber cages, although it is also possible to design

other achievements.

  A particular constitutive part

  An essential feature of the present invention is the transverse rolling mill which draws the material to be rolled. This transverse rolling mill is characterized by a mounting in the form of a rolling block of several interchangeable transverse mill stands, which each comprise at least one motor-driven bearing cage, rotating around the rolling axis, and in which are rotatably mounted several - preferably three - oblique cylinders forming a gauge, arranged inclined relative to the rolling axis, the transverse rolling mill being

  characterized by a mandrel shank, preferably

  internally cooled filter, which is retained in the axial direction of the inlet side and from there enters the caliber openings of the

transverse rolling train.

  The assembly in the form of a rolling block of several transverse rolling mill stands allows the drawing in stages, but nevertheless simultaneous,

  of a hollow block according to the process according to the invention.

  Section reductions in these various cages indi-

  viduals remain very low because of the distribution

  multi-stage reduction of the total section, so that one can also be satisfied with very

  low rolling pressures. The series of devices advancing

  It consists of small cylinders, light rolling mill stands, very low drive power and particularly good forming efficiency. The rotational masses are very small, so that the

  centrifugal forces that intervene may be

sorted without problem.

  In spite of the relatively large number of rolling stands, the result is a considerably reduced bulk compared with the known types of construction, since

  transverse rolling mills according to the invention do not

  only very small dimensions and can be

  placed very close to each other. In addition, the assembly in the form of a rolling block of several interchangeable transverse mill stands makes it possible, in a simple manner, to vary the wall thickness of the tube blank, by using more or fewer of these stands. Due to the relatively large number of

  these are thus obtained a staggering of the thick-

  tube blanks, which is generally quite sufficient, so that one can give up

  in most cases a progressive radial displacement

sif cylinders.

  The finely tuned division that is desired for the finished tubes can be obtained with the subsequent finishing rolling mill. As for modifying the wall thickness of the tube blanks using a mandrel rod presenting another

  outer diameter, this is also possible with the invention

  and even with little expense, since only one mandrel rod is used and only this one needs to be changed. In addition, the assembly in the form of a rolling block of interchangeable transverse rolling mill stands makes it possible to change the rolls and to develop the entire transverse rolling mill in a workshop designed for this purpose, while other transverse rolling mill stands. are put

implemented.

  The installation thus allows a particularly long uninterrupted rolling time, which results in a considerable improvement in the power thanks to an operation in the best

  conditions of the installation. The profitability of the plant

  In addition, the high production makes it possible, since the possibility of using large block weights makes it possible to obtain long tube blanks and long tube lengths.

  resulting in only a few unusually

  and the proportion of waste is very small. Moreover, apart from low operating costs - notably thanks to the economy of the reheating furnace - investment costs are also lower than for

  known installations with their numerous groups of

  still large and heavy, as well as their

  auxiliary and supplementary

  It is advantageous if the mandrel rod is mounted so as to be slidable axially and rotatable about its longitudinal axis. By sliding the mandrel rod, the length portions which are deteriorated by wear in the region of the oblique cylinders can be quickly and economically replaced by other unused lengths of the mandrel rod. grace

  the fact that it is mounted in such a way as to be able to

  it is possible to influence the value of the widening of the material subjected to rolling; we think there as well

  to a motor drive only braking.

  It is recommended to provide that the rotational directions of the bearing cages of transverse mill stands are opposed. On the other hand, however, it is also possible to provide that the directions of rotation of all the bearing cages of

  all transverse rolling mill stands are the same.

  In addition, there is the possibility that the transverse rolling mill stands each have two bearing housings disposed one after the other in the direction of rolling and the directions of rotation of which are opposite.

In all these forms of

  tion, it is possible to obtain a formation of the material

  milled material that cleans this material, particularly

  multiply a rolling line from each location of the material; so that the undesirable formation of bead is safely removed, and that one obtains

  very narrow wall thickness tolerances.

  Advance, cylinder width and cylinder spacing may be matched to each other such that a considered location of the material being laminated is superlaminated multiple times at locations that are always different from the working surfaces of the cylinders. and not always for example by the sections

on board.

  According to a preferred embodiment

  d of the invention, when a motor drive oblique cylinders is lacking, having or between neighboring transverse mill stands, it is

  provided at least one drive shaft provided with several -

  preferably three - driven rollers driven into the

  direction of rolling, the axes of which extend

  towards the rolling axis, the device

  and the constitution of these motor rollers being provided so as to leave free an annular interspace between the product subjected to rolling

and the mandrel rod.

By giving up a workout

  by motor oblique cylinders, it is easy to

  the constructive constitution of transverse rolling mill stands. Thanks to the motor drive then used for the bearing cage, the oblique cylinders, when the material to be rolled is inserted, still roll on its outer surface, which ensures

forming of the material.

The motor cages are however

  necessary in this embodiment of the invention.

  tion, to ensure the advancement of the material to be rolled when the drive of the rolls is lacking. It is then recommended to provide alternating succession of transverse rolling mill cages and drive shafts,

  although other modes of success may be conceived

  if we. One or two drive cages at the front of the first transverse rolling stand allow very

  sure of the hollow block in the transverse rolling train.

  In general, one does not need a last drive cage of the

  next to the end of the train, when there is no direct entry into a finishing

  shortly after the transverse rolling train.

  In addition, the use of two drive cages one after the other is advantageous in many cases because the drive rollers can not be pressed radially.

  only in a limited way against the material subjected to

  and therefore produce only a force of advance

  limited investment, so that it may be rational to

  several motor cages following one of the

* very. In the case of several motor cages - for example

  at least two - we can also use a sequence of

  different openings of calibres. A first ouxer-

  O-caliper avoids clinging of the rolling stock in the roll intervals, and a second round-round opening gives the product in the second drive shaft its round cross-section shape, penetration into the roll intervals

then being prevented too.

  Due to the limited radial pressure force, there remains between the inner surface of the product to be rolled and the outer surface of the mandrel shaft a free gap, which prevents any friction between the

  mandrel rod and the product to be rolled. Such a money

  This occurs only in the area of the oblique cylinders, after which the material subjected to rolling, however, as with the known oblique-roll mills, detaches in a radial direction from the

chuck rod.

On this subject the rolling train

  cross-section according to the invention is also differentiated

  of the known continuous train, in the case of which the product

  rolling is pressed very strongly against the over-

  outer face of the mandrel rod, which is one of the causes of high rolling pressures and a large

need power.

  In the case of a transverse rolling machine according to the invention, on the other hand, the rolling pressures and the driving powers * 25 are kept low, which makes it possible to have small and light transverse rolling mill stands and their arrangement in the form of a rolling block. In addition, the gap between the material to be rolled and the

  chuck rod, as a rule cooled inside-

  has an isolating action, so that the loss of

  The heat of the product subjected to rolling remains very low.

  Also then the heating of the mandrel rod remains relatively very low, so that it can always be re-used, and that we save the high expense of a cyclical circulation of rods. mandrels requiring a large number of stems

expensive chucks.

  According to another embodiment

  of the invention, the oblique cylinders can be

  dragged by their bearing trees. There is no need for drive cages, so that a particularly short transverse rolling mill results. In this embodiment, the oblique cylinders can be driven by means of toothed wheels which are integrally rotatably mounted on the shafts.

  bearing of these oblique cylinders and roll on a cou-

  toothed ring mounted in the casing of the transverse rolling mill cage, driven under the effect of the rotation of the

bearing cage of the cylinders.

  According to one embodiment of the invention, it can be provided that the angle of advance of the oblique cylinders is adjustable. This is necessary for example when changing the outer diameter of

  the tube blank, or when changing the location

  the cage. Advancement can thus be adjusted sepa-

  optimally on each cage location.

  Also the oblique cylinders may be constituted so as to be adjustable in radial position relative to the rolling axis. We can

  realize this adjustment possibility in particular

  It is simple in that it provides selected fillings of appropriate thickness. In this way, the size of the calibrated openings can be adapted to the different

  desired outside diameters of the tube blank.

It is also possible to

  kill the oblique cylinders so as to allow them to be adjusted in axial position relative to their axes of rotation. This last adjustment possibility has the advantage that when the working surfaces of the oblique cylinders are worn and retouched, it is possible to

  restore the initial size of the gauge opening.

It is advantageous to equip the last

  outlet side, transverse rolling mill cage,

  smoothing cylinders instead of oblique cylinders.

  As for the oblique cylinders of the transverse rolling mill stands, they are cylinders in the form of barrels, as they are common according to the known rolling mill roll stands, although with the dimensions

  significantly smaller. The smoothing cylinders

  However, the above-mentioned forms have a cylindrical shape, which is optionally also hyperbolic, as used for example in straightening machines.

with rollers.

  These smoothing cylinders are, like barrel-shaped oblique cylinders, inclined, in order to ensure an advancement of the material subjected to rolling. Their angle of advancement would also be

  be adjustable and it is good to mount them so as to allow

  set them in radial and axial position relative to the rolling axis, as the oblique cylinders also. Such a transverse rolling mill cage equipped

  of straightening cylinders is mainly used to improve

  to improve tolerances of wall thickness very low anyway; the transverse rolling operation there

lends itself particularly well.

  It is advantageous to provide the transverse rolling mill stands, on both sides of their lateral surface, with a drive shaft with trunnion or drive coupling. Each transverse rolling mill cage can then be put into place in

  each housing slot of the trans-

  versal and be operated following each direction of rota-

  bearing body. Transverse rolling mill cages are required to be suspended in the crane only to rotate them about their vertical central axis when they are to be driven in following

  the other direction of rotation of the bearing body.

  On the other hand, there is interest

  drag the transverse rolling mill cages and / or the drive shafts through a group control. The transverse rolling mill stands and the drive shafts can then also be provided with separate group controls. Group orders of this kind are known by stretch-reduction rolling trains

  put into service as finishing rolling trains

  wise, and have excellently proved them.

  As to the external construction form of the transverse rolling mill according to the invention, which means especially the

  rolling mill stands and training,

  These correspond to a large extent to

  roll stands and to drive the rolling mill

  known stretch-reducer swim. It is therefore

  It is also desirable to assemble the rolling mill cages.

  Versaux and / or drive cages on replacement carriages, as already described and represented

in German Patent No. 15 27 659.

The invention will be better understood at

  using the following description and accompanying drawings

  representing some examples of the realization of the invention

  in which: - Figure 1 is a general view

  plan of a rolling mill in accordance with the

  vention; - Figure 2 is a plan view of a transverse rolling train according to the invention - Figure 3 shows a forming section of the transverse rolling train, partially in longitudinal section; - Figures 4 and 5 are sectional and side views of a transverse rolling mill cage without driving the cylinders; - Figure 6 is a sectional view of a transverse rolling mill cage, without driving the rolls, with two bearing cages; - Figure 7 is a sectional view of a transverse rolling mill cage with the drive of the cylinders; FIG. 8 is a view from above of a transverse rolling train without drive cages; FIG. 9 shows another embodiment of a transverse rolling stand without the driving of the rolls - FIG. 10 is a front view

  of a transverse rolling train with a trolley

  ge. In Figure 1, there is shown a rotary kiln 1 which, via a loading device 2, is loaded with blocks, not shown, for example 1000 kg mass and about 5 meters in length. These blocks, heated to the rolling temperature, leave the rotary kiln 1 via a train of rollers 3, pass through an installation of

  descaling 4 and arrive via a trans-

  transverse carrier 5 in a loading channel 6 of an oblique-roll mill stand 7, where each block is perforated - according to the known method of drilling

  with oblique cylinders - to form a hollow block.

The hollow block thus obtained arrives,

  after removal of the mandrel rod, through

  of a further transverse conveyor 8, on a receiving table 10. A pair of drive rollers 11, first immobile, is radially brought against the block and holds it securely, while a mandrel shank 12, optionally internally cooled, is introduced into the block with the aid of a second pair of drive rollers 13. This introduction takes place far enough for the advancing end of the mandrel rod 12 to penetrate into the last gauge, side output, of a transverse rolling train 14. With the aid of the first mentioned pair of driving rolls 11, which is now started, the hollow block is pushed, while retaining, on the input side, the rod of

  mandrel 12, in the transverse rolling train 14.

  It is also possible to introduce at the same time, into the transverse rolling train, the mandrel rod.

  12 and the hollow block that is advanced.

  There the hollow block, long, for example, about 9 meters, is rolled into a rough tube, long, for example, about 108 meters; this

  tube blank being then equalized by the rod of man-

  Drin 12, held on the other side of the entry side. Again during rolling in the transverse rolling train 14, the tube blank thus obtained passes through its anterior end section into a finishing rolling mill - mounted directly afterwards and disposed behind at a short distance - which is constituted for example in the form of stretch-reducing rolling train. With the aid of a separating device 16, the completed tube - of a length of well over 1000 meters, depending on the final diameter can be divided into desired lengths, before arriving, via a train of rollers 17,

on a cooling bed 18.

In FIG. 2, the laminate

  Transverse swimming 14 is shown on a larger scale.

  Ordered by a group order 19 - analogous to

  that which is also used for

  known stretch-reducer - these are two different types of

  of rolling mill stands that are driven. In pre-

  first, it is transverse rolling mill stands 20

  provided with oblique cylinders 21, mounted so as to

  see turning in a bearing housing 22, which rotates about the rolling axis designated 23, being driven for this purpose via a conical wheel control 24 (see following figures). The transverse rolling stand 20, which is the last on the outlet side, has, in place of the oblique rollers 21, smoothing rollers 25, having a shape

slightly hyperbolic.

  At the front of each transverse rolling mill stand 20 and following the last stand 20, there is mounted a drive cage 26 provided with drive rollers 27 (FIG. 3), which are also driven from the control unit in groups 19. that we have always shown in Figure 2 that two oblique cylinders

  21 and two drive rolls 27 per cage, so as to

  to better represent their shape and the caliber aperture each caliber is constituted, however, in all, by three cylinders or rolls respectively, distributed on the periphery, which is valid elsewhere

  also for the finishing mill 15.

  In FIG. 3, it can be seen that the oblique cylinders 21 operate in a manner similar to that known from the known oblique roll rolling method. The rolling product 28 which moves from left to right on the

  Figure 3 is reduced in cross section - in particular

  to bind with respect to its wall thickness - by the oblique cylinders 21, where it follows that the rolled product 28 is detached from the mandrel rod 12. In the region of the drive rollers 27 mounted upstream and in alN,

  the product to be rolled 28 is compressed, certainly,

  radial contact, but only until there remains a gap 29 between the product 28 and the mandrel rod 12. Direct contact between the rolled product 28 and the mandrel rod 12 is in the form of a line, so

  only in the area of the reducing part of the cylinders

  obliques 21; which facilitates the advance of the product subjected to rolling, reduces the wear of the mandrel rod

  and keeps his warm up low, or the loss of heat

  28. Figures 4 and 5 show how the bearing cages 22 are mounted in a casing 30 of the transverse rolling mill cage 20 and the oblique cylinders 21 in the bearing cage 22. The conical wheel drive 24 of FIG. this one is also clearly recognizable. Via a coupling 32,

  a drive shaft 31 transmits the rotational torque

  of the group drive 19. Stroke lines on the opposite side of the side surface of the housing 30 are shown in FIG.

  second drive shaft 31 with one half of

  32, in order to show that we can

  the transverse rolling mill stand 20 about its central axis

  vertical tral; so that the oblique cylinders 21 can also be mounted on the right side - on the

  FIG. 4 - of the transverse rolling mill stand 20, and

  then rotate in a reverse direction of rotation. FIG. 5 further shows that the oblique cylinders 21 are mounted inclined in two ways with respect to the axis

rolling 23.

  Figure 6 corresponds for the essential

  in Figure 4, but shows, however, that it is pos-

  sible to provide the arrangement of two bearing cages 22 and two sets of oblique cylinders 21 in a single casing 30, the two bearing cages 22 then rotating

in opposite directions of rotation.

Figure 7 also corresponds

  essentially in Figure 4, but shows a possibility

  how the oblique cylinders 21 can be driven. These oblique cylinders 21 are fixed integrally in rotation on their bearing shafts 33, which, at their end situated opposite the oblique cylinders 21, also rotate a gear 34. These toothed wheels 34 are engaged in a ring gear. toothed 35 stationary, secured to the housing; so that during a rotational movement of the bearing housing 22, each gear wheel 34 rolls on the ring gear 35, and the oblique cylinders 21 are thus driven through the bearing shafts

33.

  FIG. 8 shows a transverse rolling train 14 which is equipped only with

  transverse rolling mills 20, of the type of construction

  form in FIG. 7. Thanks to the drive of the oblique cylinders 21 and also the smoothing cylinders 25,

  no need for motor cages as in the form of

according to Figure 2.

  Figure 9 shows two motor cages

  these 26 and a transverse rolling mill stand 20 with

  Laterally mounted trainer, which allows small diameters

  conical wheels and low peripheral speeds

  c. The oblique cylinders 21 are no longer door-to-door

  false but supported on both sides, and further the angle of advance of these oblique cylinders 21 can be adjusted with great sensitivity with the aid of several toothed annular discs 36 engaged with each other. For this purpose, the bearing body, designated 37, is rotated in the direction of the arrow.

  oblique 21. Thanks to appropriate adjustment elements -

  cushion packing, not shown or toothed annular discs 36 of other thickness, the position can be adjusted

  oblique cylinders 21 in the radial direction with respect to

bearing to the material to be rolled 28.

Figure 10 shows how

  transverse rolling mill stands 20 are maintained,

  the functioning of the installation, which is

  The same applies also to motor cages.

  26, not shown in FIG. 10. The transverse rolling mill stands 20 are brought there by a spare carriage 38, which can be circulated to the left in FIG. 10, which has been indicated by FIGS. lines in dot-dots. During operation, each cage is maintained both radially and

  axial direction, by means of a clamping device 39.

  In this respect, the transverse rolling mill according to the invention corresponds to the known type of construction and

  standard for reduction gearing rolling trains 15.

  As there the mechanism of the control group 19 is housed in the frame 40 of the transverse rolling train 14, where it is driven by motors 41, via

of trees 42.

  Outside the realization of the

  trainement by order in groups 19, it is perfect-

  it is possible to drive the roll cages separately

  transverse blacks 20 and the drive cages 26. In order primarily to protect the oblique cylinders 21, but also the drive rolls 27, it may be rational to have guides, between the transverse rolling mill cages or drive cages 26 respectively, which are even to guide the mandrel rod 12 radially, when its anterior end portion, at the beginning of the rolling operation without hollow block, is introduced into the gauge openings. During the operation of the rolling mill, such guides are not necessary, and are not necessary even when the end

  of the mandrel rod is introduced, joint-

  with the supplied hollow block, in the calibration apertures

cages 20 and 26.

RE VE N DI C A T I 0 N S

  1) Method, installation and rolling train for making seamless tubes, according to

  which a hollow block, heated to the temperature of

  swimming, perforated end to end in the longitudinal direction,

  a mandrel rod inserted therein is stretched without rotation.

  in a tube blank, and this is

  laminated without intermediate heating to form a finished tube, characterized in that the drawing of the hollow block is carried out only by means of a

  transverse rolling operation (14), divided into several

  if they are in continuous operation, simul-

temporarily on the same hollow block.

  2) Process according to claim 1, characterized in that the transverse rolling operation

  is performed alternately in both directions of rota-

  possible, preferably from step to step.

  3) Process according to any one

  Claims 1 and 2, characterized in that stretching

  of the hollow block is carried out according to larger steps

  on the side of the entrance than on the side of the exit.

  Be) Rolling instaltation for carrying out the process according to any one of

  claims 1 to 3, characterized in that a train of

  transverse rolling (14) is arranged, forming a

  block stage, directly following a roll stand (7) with oblique cylinders, known per se, for the purpose of

  perforation, and directly to the front of a laminate

  finisher swim (15) also known.

  5) transverse rolling mill according to claim 4, characterized by a mounting in the form of a rolling block, several interchangeable transverse mill stands (20), each comprising at least one bearing housing (22) driven by motor rotating around the rolling axis (23), and

  in which are mounted so as to be able to rotate more

  sieurs - preferably three - oblique cylinders (21) forming a gauge, arranged inclined relative to the rolling axis (23), this transverse rolling train being also characterized by a mandrel rod (12), preferably cooled internally , which is retained in the axial direction on the inlet side and from there enters the caliber openings of the cages (20, 26)

  said transverse rolling train (14).

  6) Rolling train according to claim 5, characterized in that the mandrel rod (12) is slidably mounted in the direction of

  axial and rotatable about its longitudinal axis.

7th) Rolling train according to one

  either of claims 5 and 6, characterized in that

  the rotational directions of the bearing cages (22) of adjacent transverse rolling mill cages (20) are opposite. 8) Rolling train according to one

  either of claims 5 and 6, characterized in that

  the direction of rotation of all bearing cages (22) of all transverse rolling mill stands (20)

are the same.

9) Rolling train according to one

  either of claims 5 and 6 characterized in that

  the transverse rolling mill cages (20) each comprise two bearing cages (22) arranged one after the other in the rolling direction, and

  whose directions of rotation are opposite.

10) Rolling train according to one

  any of claims 5 to 9, characterized in that

  only when a motor drive of the oblique cylinders (21) is missing, in front or between adjacent transverse rolling mill stands (20), is there at least one drive shaft (26) provided with several - preferably three - rollers motors (27) driven in

  the direction of rolling, the axes of which extend

  in the direction of the rolling axis (23), the arrangement and the constitution of these drive rollers being provided so as to leave free an annular space (29) of annular shape between the product (28)

  subjected to rolling and the mandrel rod (12).

11) Rolling train according to

  claim 5 or any one of claims 6

  to 9, characterized in that the oblique cylinders (21) are driven through their shafts.

bearing (33).

  12) rolling train according to claim 11il, characterized in that the oblique cylinders (21) are driven by means of toothed wheels (34), which are integrally rotatably mounted on the bearing shafts (33) of these cylinders oblique (21) and roll on a ring gear (35)

  mounted in the casing (30) of the trans-

  versal (20), driven by the rotation of the

  bearing cage (22) of these cylinders.

) Rolling train according to

  claim 5 or any one of the claims

  6 to 12, characterized in that the angle of anchorage of

  oblique cylinders (21) is adjustable.

14) Rolling train according to

  claim 5 or any one of the claims

  6 to 13, characterized in that the oblique cylinders (21) can be adjusted in radial position with respect to

the rolling axis (23).

 ) Rolling train according to

  claim 5 or any one of the claims

  6 to 14, characterized in that the oblique cylinders (21) can be adjusted in axial position with respect to their

axes of rotation.

16) Rolling train according to

  claim 5 or any one of the claims

  6 to 15, characterized in that the last one, on the left side,

  transverse rolling mill cage (20) is equipped with cylinders

  straighteners (25) in place of oblique cylinders (21). 17) Rolling train according to

  claim 5 or any one of claims 6

  16, characterized in that the rolling mill stands

  versaux (20) are provided on both sides of their lateral surface with a drive shaft (31) with

  trunnion or coupling (32) provided for the drive.

18) Rolling train according to the

  claim 5 or any one of claims 6

  17, characterized in that the rolling mill stands

  (20) and / or the drive cages (26) are driven

  through a group command.

18) Rolling train according to

  claim 5 or any one of the claims

  6 to 18, characterized in that the rolling mill stands

  (20) and / or the motor cages (26) are

  on replacement carriages (38).