CN106238497B

CN106238497B - Method for manufacturing metal pipe, method for operating seamless pipe equipment, pipe jacking machine, seamless pipe equipment

Info

Publication number: CN106238497B
Application number: CN201610404850.7A
Authority: CN
Inventors: 皮特·蒂文; 赫尔吉·丹尼尔
Original assignee: SMS Group GmbH
Current assignee: SMS Group GmbH
Priority date: 2015-06-09
Filing date: 2016-06-08
Publication date: 2020-04-10
Anticipated expiration: 2036-06-08
Also published as: RU2016119243A; CN106238497A; ITUA20163628A1; AT517326B1; ES2600455R1; RU2690621C2; ES2600455A2; DE102015109092A1; ES2600455B1; AT517326A3; RU2016119243A3; AT517326A2

Abstract

In order to produce seamless metal pipes with a diameter of more than 7 inches, i.e. 17.78 cm, at low cost, it is provided that the push bench undertakes the work of the set arranged before the push bench in the conventional production link or that the work is delivered to the set arranged after the push bench in the conventional production link.

Description

Method for manufacturing metal pipe, method for operating seamless pipe equipment, pipe jacking machine, seamless pipe equipment

Technical Field

The invention relates to a method for producing metal tubes from a billet, wherein the billet is first perforated, then drawn in a push bench and then finish-rolled into a tube, wherein the push bench preferably comprises at least two push rod assemblies with different push rod diameters. In addition, the invention relates to a method for operating a seamless tube plant with a piercing mill, a push bench arranged after the piercing mill and a finishing mill (in particular a stretch reducing mill) arranged after the push bench, wherein for producing a seamless tube from a billet, the billet is first pierced in the piercing mill, then drawn in the push bench and then finish rolled into a tube in the finishing mill. The invention also relates to a push bench with a push rod and at least two rollers placed in a ring bed. The invention further relates to a seamless tube plant having a piercing mill, a push bench arranged downstream of the piercing mill and a finishing mill (in particular a stretch reducing mill) arranged downstream of the push bench, wherein the mill is designed on the basis of a series of bore diameters and the push bench comprises at least two push rod assemblies with different push rod diameters.

Background

Conventional methods for manufacturing metal pipes or for operating corresponding seamless pipe plants, as well as conventional pipe push mills or conventional seamless pipe plants, have been fully disclosed by the prior art. In particular, in a corresponding seamless tube plant and a method for operating such a seamless tube plant, it is possible to use, as a piercing mill, for example, a cross-rolling piercing mill (for example, a conical cross-rolling mill) and/or a stretch-reducing mill as a finishing mill.

In particular, for example, patent document DE 3742155 a1 describes a method for producing seamless tubes, in which an open-ended hollow shell is first provided at its front end by reducing its inner diameter with a thrust bearing for the end face of a mandrel which is pulled in the longitudinal direction by a drawing frame (in which the pass is formed by three or four loosely running rollers) which is arranged in succession in a frame machine, and is then driven through the drawing frame by means of the pulling of the mandrel and thus reduces its outer diameter and elongates on the mandrel.

Furthermore, patent document EP 1498193 a1 discloses a method and apparatus for producing a metallic seamless pipe, in particular a seamless steel pipe, from a billet rolled or cast in the shape of a rod, wherein the method is characterized in that after a mandrel bar is fed into a thick-walled hollow body perforated by the billet, the bottom of the hollow body is removed, the hollow body is subsequently stretched, and the end of the tube of the stretched hollow body facing the feed-in side of the push bench is collided before stretching on the push bench, thereby avoiding the incomplete upper surface due to errors in the bottom of the thick wall at the time of stretching and stretching, which in turn leads to a significant improvement in the quality of the seamless pipe.

Patent documents DE636741C, DE640955C and DE911365C also disclose push bench machines in which following rollers are arranged between the drawing apertures and driven or drivable friction aperture rollers are arranged between the friction apertures, respectively, in order in this way to alleviate the form fit in the region of the bottom impact and thus to achieve a higher drawing ratio.

Disclosure of Invention

The object of the present invention is to enable the manufacture of seamless metal tubes at low cost, especially for medium and large diameters, and for seamless metal tubes with a diameter exceeding 7 inches (i.e. 17.78 cm).

The above object is basically achieved in that the push bench undertakes the tasks of the set arranged before the push bench in the conventional production link or the tasks are given to the set arranged after the push bench in the conventional production link. Based on this basic idea there are numerous specific solutions which, although they only adjust the actual task in the production phase, surprisingly enable a cost reduction in the production of seamless metal pipes, in particular for medium and large diameter seamless metal pipes.

The production of seamless metal tubes, in particular for medium and large diameters, and for seamless metal tubes with a diameter of more than 7 inches (i.e. 17.78 cm), can be realized at low cost by a method for producing metal tubes from a billet in which the billet is first perforated, then drawn in a push bench and then finish-rolled into a tube, characterized in that the perforated billet is first pushed on the push bench by at least one roll arranged in the drum of the push bench. In this case, the billet which has not yet been perforated can first be pierced in a known manner to form a hollow billet or the perforated billet, wherein the hollow billet then continues to be drawn into a tube blank in a push bench, with the exception that the hollow billet or the associated tube blank is first additionally pushed or moved by a drive element of at least one roller of the push bench towards the push rods or only in the conveying direction or the impact rolling direction of the push bench. Preferably, the drive element comprises a roller of a drum. The forces acting on the billet are exerted by the driving elements of the push bench itself, in particular at the beginning of the impact process, not necessarily only by the push rods, but necessarily also by the interaction between the push rods and the perforated billet. Thus, the expense previously required to achieve such interaction (e.g., collision) may be reduced, which correspondingly reduces costs.

In this connection, the push bench is characterized by a drive device, by means of which the roller or at least one roller of the first roller in the impact direction of the push bench can be actively deflected in rotation, thereby driving the hollow billet or pipe so that such a roller then functions as a roll. Thus, if the push bench is characterized in that at least any one of the rollers in the striking direction of the push bench is provided with at least one driven or drivable roller, seamless metal pipes, especially of medium and large diameter, and of diameters exceeding 7 inches (i.e. 17.78 cm), can be manufactured at low cost by means of a push bench having a push rod and at least two rollers placed in a ring bed. This also results in a corresponding cost reduction by eliminating measures which have to be implemented in particular before (for example collisions), or in a corresponding cost reduction.

In this regard, the pierced billet may first be pushed on the push bench by at least one roll arranged in the barrel of the push bench and this is continued at least until the friction fit between the push rod and the pierced billet or billet is sufficiently high that pushing can be accomplished by the push rod as in conventional push benches. It is obvious that a plurality of rolls and a plurality of cylinders can participate here.

As an accumulation or alternative to the above-described use of drive means in the rollers of a push bench, the manufacture of seamless metal tubes, especially for medium and large diameters, and for seamless metal tubes with a diameter exceeding 7 inches (i.e. 17.78 cm), can be realized at low cost by a method for manufacturing metal tubes from billets in which the billet is first pierced, then drawn in a push bench and then finish rolled into a tube, said manufacturing method being characterized in that at least the rollers of the first roller of the push bench realize a friction fit between the push rod of the push bench and the pierced billet or billet so that the forward thrust of the pierced billet or hollow billet can be supported or only carried out by the forward movement of the push rod. In contrast to known push bench or corresponding known production methods, in which the friction or form fit between the push rod and the perforated billet is achieved by previously implemented measures (for example by means of collisions), or (as shown in patent documents DE636741C, DE640955C and DE 911365C) only rollers in the roller bore act frictionally in a complementary manner, these measures (i.e. the friction fit which is possible only during the impact between the push rod and the perforated billet) being able to be implemented on the push bench itself. By achieving a friction fit between the ejector pin and the pierced billet, the billet can be pushed through the ejector pin itself (as in conventional push bench machines).

It is clear that the rolls responsible for the thrust and the rollers that achieve the friction fit can exhibit corresponding advantages both together and individually. For example, on the one hand the rolls responsible for pushing can drive the billet individually through the aperture formed by the rollers of the push bench until the friction between the push rod and the push bench as a whole reaches a sufficiently large degree, so that pushing by the rolls can be dispensed with and can be pushed by the push rod alone as in conventional push benches. On the other hand, it is also conceivable that, in the case of the roller responsible for the pushing being dispensed with, the roller of the first drum is to achieve sufficient interaction between the ram and the perforated billet in order to be able to complete the pushing by means of the ram. Furthermore, it is also possible to combine these measures in such a way that the roller first pushes the help roller (including the roller if necessary) through corresponding measures (for example by reducing the diameter of the first roller) to enhance the friction fit between the push rod and the perforated billet.

Alternatively or in addition to the friction fit between the mandrel and the perforated billet achieved by the rollers of the first roller, the perforated billet or billet may be impacted on a push bench and/or rolled on the mandrel by at least the rollers or rolls of the first roller. The collision on the push bench determines that the measures previously carried out before the push bench in the conventional method of producing seamless or seamless metal tubes from billets can now be carried out on the push bench and therefore consume less time, which entails a reduction in the cost of carrying out the method. In this case, the collision can be carried out by a separate unit, which, however, would therefore incur the expense of a further unit. Likewise, the collision can be done by rollers or rolls of the push bench, in particular of the first roller. The rolling on the ram can also be done by means of rollers or rollers of the push bench, preferably by means of rollers or rollers of the first drum of the push bench. Wherein, a plurality of rollers can also participate.

The production of seamless metal tubes, especially for medium and large diameters, and for seamless metal tubes with a diameter of more than 7 inches (i.e. 17.78 cm), can therefore also be achieved at low cost by a method for producing metal tubes from a billet in which the billet is first perforated, then drawn in a push bench and then finish-rolled into a tube, said production method being characterized in that the perforated billet, which is loosely arranged on the push bench, is collided on the push bench at least by means of rollers of a roller and/or rolled on the push bench before being drawn on the push bench. It is obvious that it is advantageous if these measures can be implemented individually and cumulatively, in particular in combination with the measures that at least the rollers of the first drum of the push bench effect a friction fit between the push rods of the push bench and the perforated billet, and/or that the perforated billet is first pushed on the push bench by at least one roller arranged in the drum of the push bench, in particular to shorten the implementation of the method in a cost-effective manner, i.e. to avoid collisions, for example, before the perforated billet is placed on the push bench. This solution differs in particular from the solution of US2819790, in which the collision is performed on the push bench, but with specially designed dish-shaped female pliers, which makes it possible to dispense with the use of additional guide means for the long push rods, since the first rollers are used directly for guiding.

Cumulatively or alternatively, the production of seamless metal tubes, in particular for medium and large diameters, and for seamless metal tubes with a diameter of more than 7 inches (i.e. 17.78 cm), can also be achieved at low cost by a method for producing metal tubes from a billet in which the billet is first pierced, then drawn in a push bench and then finish-rolled into a tube, said production method being characterized in that the billet has a constant and continuous inner diameter at the time of piercing and is then fed into the push bench without collisions. In other words, this means that it is possible to give up colliding or leaving the bottom or the like in the pierced billet or the pierced shell intact, and give the pierced billet or the pierced shell without the fold or the collision to the push bench. In this connection, for further processing, the pierced billet or shell is fed into the push bench without a corresponding collision, in particular easily collided by the push bench if necessary, which therefore results in a small amount of scrap.

By means of the production method described above, at least one method step can be carried out in a time-saving manner, or a method step can be eliminated, whereby a perforated billet or a related tube blank can be worked relatively quickly, in particular whereby a hotter working can be carried out, in particular by means of which a beneficial effect in terms of deformation results and costs can be achieved.

Obviously, while effective for making a particular metal tube from a billet, other process steps may be added to the manufacturing process, such as separating the tube blank head, expanding, or the like.

It is furthermore advantageous that for the purpose of collision or rolling on the push rods, the pierced billet is collided on the push bench at least by the rollers of the first drum of the push bench and/or rolled on the push rods, because here the good interaction or internal friction fit created between the hollow billets or tube blanks can quickly make it possible to push the tube blanks with the push rods and can be collided again with quite conventional process technology.

It is particularly beneficial if the entrained rollers and/or the surface of the workpiece is lubricated before it passes over the entrained rollers to reduce the impact forces to be applied during manufacture. This advantageous lubrication can be effected, for example, only by partial application of the lubricant, so that it is not necessary to carry out the lubrication over the entire circumference of the pierced billet or tube, which correspondingly reduces the costs. This applies in particular when the driven rolls are arranged in the same drum as the drawn rollers, which can be lubricated correspondingly. With proper lubrication, higher friction can be tolerated in the region of the roll, so that the roll or rolls can perform the thrust function correspondingly well. If the roll should subsequently pass through an area that is not lubricated or is slightly lubricated, lubrication can be performed there, when such lubrication proves to be beneficial.

In this connection, since this can be achieved technically simply, it is possible to intentionally lubricate only the traction rollers of the rollers in which no rollers are driven, and/or the workpiece surface before it passes through such rollers, since a better friction fit can thereby be achieved. In particular, the risk of the friction fit of the driven rolls and the hollow billet or tube blank being reduced by the lubricant can be reduced thereby. It is therefore advantageous that the relevant lubricating operation is preferably carried out only at the cylinders containing the non-driven or non-driven rolls.

If only the rollers of the rollers with only the traction rollers and/or the workpiece surface are lubricated before they pass through such rollers, the relevant lubrication process can be realized in a technically particularly simple manner.

It is clear that the above-mentioned measures for lubricating the rollers can also be used independently of other technical features of the invention, and are advantageous in push bench machines with rollers comprising traction rollers and driven or drivable rollers or rolls.

It is also beneficial that the ram of the push bench is impacted through the loop bed of the push bench at an elevated impact velocity and/or at an impact velocity of no more than 4 meters per second. In particular, the initial friction fit can be established particularly effectively if the ram is struck at an elevated striking speed or at a limited striking speed coordinated with the respective workpiece material. Wherein the impact speed should be coordinated with various materials of the billet or the ram, or set as a coordinated upper speed limit obtained from a table obtained through experiments. It is disclosed in DE3021940 that the push rods are hit by the push bench at an elevated impact speed, but wherein the document is arranged that the already hit perforated billets are hit by the push bench with an elevated impact speed, especially when the impact is dispensed with, or essentially a friction fit, rolling on the push bench or other operation propelling the perforated billets to be hit is arranged in the impact process.

In the production method according to the invention, an approximately self-sufficient impact process can be realized in a structurally simple manner. I.e. when the pierced billet, at least until it reaches the first roller of the push bench and comes into contact with the rollers and/or rolls of this roller, is placed on the ejector pin by means of a separate positioning device and/or is conveyed in the direction towards this roller by means of a separate push-in aid. In particular, a pushing aid (e.g. an additional plunger or a separate gripper) or a positioning aid (e.g. a corresponding, later releasable shoulder on the ram foot) pushes the pierced billet until a possible collision process occurs, until there is a friction fit between the ram and the pierced billet, or until there is a sufficient, growing effective connection between the ram and the pierced billet. In this way, during the proper method execution, the perforated billet can be positioned correctly on the mandrel, in particular until such time as a sufficiently specific connection between the mandrel and the perforated billet is formed, for example by collision or by friction fit. It is contemplated that the separate positioning device and the separate push assist device exert sufficient force to actively impact the perforated billet through the push bench at least during the initial stage of the impact process, at least until there is a sufficient force or friction fit. In particular, higher control costs result because the stretching of the workpiece material at impact must be taken into account. Advantageously, the separate positioning means and the separate insertion aid, if they are present, have an influence on the position of the pierced billet until a collision occurs or until a friction fit is formed, so that the pierced billet can be collided or friction fit at a predetermined position purposefully, for example by activating rollers or rollers. The positioning device or push-in aid then releases the pierced billet, which is in force, friction or form fit with the push rod in the latter manner, and the pierced billet is driven through the push bench by the push rod and, if necessary, the rollers only.

The production of seamless metal tubes, in particular for medium and large diameters, and for seamless metal tubes with a diameter of more than 7 inches (i.e. 17.78 cm), can therefore be realized at low cost by a push bench with a push rod and at least two rollers placed in a ring bed, which push bench is characterized in that it comprises positioning means for placing the perforated billet on the push rod and/or pushing means for conveying the perforated billet located on the push rod in the direction towards the rollers, since the forces exerted on the perforated billet before loading the billet on the push bench can thereby be reduced with the corresponding advantages described above.

Positioning means which position the perforated billet on the push rod and in this way ensure that the perforated billet passes through the bore of the push bench with the impact of the push rod via a form and/or friction fit which is facilitated by the positioning means between the push rod and the perforated billet, may be designed to release the form and/or friction fit when a sufficient direct friction fit is provided between the perforated billet or hollow shell and the push rod. For example, snap-in shoulders or a retractable fastening element or the like can be used as positioning means.

As mentioned above, it is advantageous that the billet has a constant and continuous inner diameter at the time of piercing and then is sent into the push bench without collision. Thus, the production of seamless metal tubes, especially for medium and large diameters, and for seamless metal tubes with a diameter of more than 7 inches (i.e. 17.78 cm), can be achieved at low cost by a method of producing a metal tube from a billet in which the billet is first pierced, then drawn in a push bench comprising at least two ram assemblies with different ram diameters, and then finish-rolled into a tube, characterized in that the billet is pierced with an inner diameter adapted to the respective ram diameter.

If the billet is pierced with an inner diameter adapted to the diameter of the respective ram, the hollow billet or tube blank can be better adapted to the diameter of the ram, so that the collision of the hollow billet or tube blank can be achieved more simply. In particular, this collision can be avoided if necessary, if a sufficiently good friction fit can be produced more simply between the ram and the hollow billet or tube.

It is clear that, in addition to the piercing of the billet into a hollow billet and the subsequent drawing into a tube, further method steps can also be carried out, for example, head separation, expansion or the like. In particular, the method steps can also be carried out with the aid of a separator if necessary. It is obviously advantageous that the perforation with matching inner diameters can be combined in particular with the remaining technical features described above.

In addition or as an alternative to the above, the production of seamless metal tubes, in particular for medium and large diameters, and for seamless metal tubes with a diameter of more than 7 inches (i.e. 17.78 cm), can be realized at low cost by a push bench with a push rod having a shaft shoulder at its top which is thicker than the other working rods, and at least two rollers which are placed in a ring bed. Such a shoulder may make the friction fit between the carrier rod and the perforated billet easier or it may already be possible to separately ensure the friction fit between the carrier rod and the perforated billet. In this way, especially when a collision is performed on a push bench, the collision can be completed, for example, at a lower cost. Likewise, a roller which should provide a friction fit if necessary can provide a friction fit against the shoulder and thus against the ram at the expense of less deformation. If the difference between the inner diameter of the pierced billet and the outer diameter of the shoulder is small, it may also be sufficient to drive the shoulder only into the pierced billet to provide the necessary friction fit so that the ram ensures that the pierced billet or tube can be pushed in the conventional manner. Depending on the specific processing method or design of the push bench, the shoulder can be used as a positioning device for positioning the hollow billet on the push rod by means of a form fit or friction fit, at least at the beginning of the impact.

If necessary, the shoulder can be driven out of the tube blank during the impact, wherein if necessary only a small tube blank space can remain on the shoulder, which serves as a waste tolerance or whose inner diameter can be adapted again to the inner diameter of the remaining tube blank in a subsequent process.

Furthermore, the shoulder can be arranged on the ram in a detachable manner, so that it can be quickly replaced and used even as a wear part if necessary.

It is clear that the above-mentioned shoulders can advantageously be used cumulatively accordingly, in particular in conjunction with the driving rolls (in particular at the first roll or at any of the first rolls), or with other driving elements with or as positioning means, or with the thrust means, or with the rollers which effect a friction fit, or with a collision-free fit.

In particular, the production method described here can be advantageously carried out with the aid of the above-described push bench, wherein the production process can be shortened in time when the processing method is adapted, so that the billet to be worked can be subjected to the subsequent method steps to completion considerably hot.

In the present case, there is a distinction between rollers, which as a generic concept are in contact with the workpiece in a rolling and usually deforming manner, and rollers, which are rollers which interact with the workpiece in a driving manner or with one another. Usually, the rollers are traction or non-driven, which can be achieved more simply in terms of control technology, wherein in certain operating conditions, for example when all the propulsion in the pipe push bench can be ensured by the push rods, it is also possible to only pull the rollers.

Furthermore, it is also possible to provide a plurality of rollers with at least one driven roller, wherein preferably one initial roller is visible in the conveying direction (impact rolling direction) or a plurality of initial rollers are visible in the conveying direction.

It should again be pointed out here that the driven rollers can then be moved together as rollers or dragged together when a friction fit is formed at other locations between the ram and the workpiece.

Furthermore, if the push bench has a push device for conveying the pierced billet on the push rod in the direction towards the drum, no friction fit or additional positioning device is required for the push rod, since the existing push device is capable of producing a pushing action. For example, the pushing means may comprise rollers, but said rollers preferably function in such a way that no or only a small negligible deformation occurs. If necessary, the pushing device can also comprise a cart or a separate slide or the like. Such a drive-in device obviously means that more expenditure is involved in terms of construction, but it can also be compensated for, depending on the case, by eliminating the otherwise necessary crash device and by carrying out the process in a strict manner. Preferably, the pushing device can then release the pierced billet when a sufficient force, friction or form fit is ensured between the ejector pin and the pierced billet, so that the pushing aid is only used to accurately position the pierced billet relative to the ejector pin until such positioning is ensured by other means.

In particular, when the perforated billet lying on the ram is conveyed by the pushing device in the direction of the drum, the impact process can be optimized until otherwise a sufficient friction fit between ram and billet is ensured and the billet is pushed in sufficiently by the ram, which means that the known method is returned. It is clear that, in particular in addition to the friction fit, it is also possible to use some supplementary measures, such as the other measures described above.

If necessary, the inner diameter of the workpiece can be adjusted again in the separating or finishing mill if deviations from the nominal value, for example from a constant inner diameter, occur as a result of the shoulder at the top of the ram.

Furthermore, the stretching action and/or the friction fit can be positively increased when at least one of the rollers is provided with four rollers or rolls forming the circular pass of the roller. This also improves the transmission of the impact force of the ram.

When the rollers are provided with two driven rollers and two drawn rollers, the hollow billet or billet can be pushed better in the transport direction in the area of the push bench. In particular, this design can be implemented relatively simply on the machine construction.

Furthermore, it can be advantageous to improve the manual handling of the hollow billet, in particular to improve the positioning or feeding of the billet, when the positioning device and/or the push-in aid comprises a handle which is movable parallel to the push rod and can be released from the hollow billet and/or a device which is movable parallel to the push rod and can be released. In this case, the handle or the device can be provided with its own drive, for example, on the plunger, for the latter, in this case the handle and/or the device on the ram for the insertion aid and can be driven by the ram in such a way that they place the billet on the ram and thus act as a positioning device.

Another advantageous solution is that the handle and/or the device can be coupled to the push rod so that the handle becomes a positioning device which positions the hollow billet relative to the push rod and synchronizes the movement of the billet with the movement of the push rod until it should be released, which can be done by opening the handle or by decoupling, whereby the transfer action can be improved again.

Also, as an addition or alternative to the above, the manufacture of seamless metal tubes, especially for medium and large diameters, and for seamless metal tubes with a diameter exceeding 7 inches (i.e. 17.78 cm), can be realized at low cost by a push bench having a push rod and at least two rollers housed in a loop bed, in which on the one hand the length of the loop bed of the push bench is shorter than or equal to 2 times the workpiece length of the longest through-push bench workpiece of all series of apertures for which the push bench is designed; and/or on the other hand in which the rollers can be laterally incorporated into the loop bed.

For the first alternative, a small stretching ratio may be mandatory in view of the length of the loop bed. In addition, the push bench can be constructed more compactly. This therefore reduces the costs, wherein all the missing drawn lengths can also be achieved, if necessary, in part by the preceding or following machines of the respective seamless tube plant.

As a second alternative, the rollers can be installed in the loop bed at technically low expenditure (e.g. without lifting devices or the like), since they can be installed laterally into the loop bed. In particular, this makes it possible to build the push bench more compactly and thus at a lower cost.

A related alternative is that the length of the loop bed of the push bench is shorter than or equal to 1.5 times the workpiece length of the longest workpiece through the push bench of all aperture series for which the push bench is designed, so that the above-mentioned effect is achieved more clearly.

Other alternatives are equally applicable where the length of the loop bed of the push bench is shorter than or equal to 1.3 times the workpiece length of the longest workpiece through the push bench of all aperture series for which the push bench is designed.

Advantageously, when the loop bed has at least two laterally open drum receptacles, the entire structure can be further developed in terms of construction, as a result of which the advantages of the second alternative can be correspondingly better achieved.

It is also advantageous to provide a transverse transport device between each roller receptacle and each change position arranged on the side of the loop bed corresponding to the respective roller receptacle. The transfer of the rollers can thereby be further simplified, in particular very fast. This therefore ultimately contributes to cost reduction due to speed advantages. In particular, by means of the transverse transport device, the respective drum can be removed quickly from the loop bed and fed in again, in particular, if necessary simultaneously, in the respective drum, which, unlike for example a crane, has to be operated in the respective sequence.

In this case, it is advantageous if the push bench has a roller carriage which is arranged laterally to the loop bed and can be moved parallel to the impact direction of the push bench, wherein the roller carriage has at least two roller bearing arrangements which are arranged indirectly on the roller carriage in the relevant exchange position. By this design, the pipe push bench and surrounding units can be replaced very quickly. In this way, all the cylinders to be exchanged can be prepared on the roller changer, the cylinders to be exchanged can be transferred to the roller changer by means of the transverse transport device during the exchange, and the position of the roller changer can then be rearranged in such a way that the cylinders to be exchanged are located in the exchange position in order to be transferred into the cylinder receptacle by means of the transverse transport device.

In particular, when the roller changer has at least two sets of two roller bearing arrangements, it is possible to provide roller assemblies arranged in a compact manner relative to one another very quickly, wherein the two roller bearing arrangements belonging to the first bearing arrangement are arranged at intervals on the roller changer in accordance with the respective change position, and the two roller bearing arrangements belonging to the second bearing arrangement are arranged at intervals on the roller changer in accordance with the respective change position, wherein the two bearing arrangements are arranged on the roller changer offset parallel to the impact direction of the push bench by an offset. Any of the two replacement positions of the support device can then be realized simultaneously by the offset.

If the offset is smaller than the length of the ring bed, preferably smaller than the distance between the first and the last support means of any one of the support assemblies in the impact direction of the push bench, in particular smaller than the distance between two adjacent support means of any one of the support assemblies, the path of the roller change carriage during the change can be reduced or at least significantly reduced and thus the change process can be accelerated.

It should also be mentioned here that the distance of any two adjacent supporting means does not have to be the distance of the supporting means next to each other if the rollers are not arranged equidistantly.

In particular, the safety of the push bench can be increased if at least one roller receptacle has an overload protection which can be opened upward and/or a locking device which acts parallel to the transverse conveyor, by means of which the roller located in the roller receptacle can be moved upward when the push bench is overloaded, and the locking device prevents the roller from being moved out in the direction of the transverse conveyor. It is clear that the upwardly openable overload protection can be configured in many ways, as long as it is possible here to prevent the drum from being unintentionally moved out sideways. In particular, it works well at the side of the push bench, since removal does not take place sideways as in replacement. In particular, this can improve the safety of operation. The locking means acting parallel to the transverse conveyor may be realized, for example, by means of a protective wall, a latch in a guide rail or the like. In this way lateral dislodgement and the associated potential hazards to humans and machinery can be minimized when overload occurs during an impact.

According to another aspect of the invention, the manufacture of seamless metal tubes, especially for medium and large diameters, and for seamless metal tubes having a diameter exceeding 7 inches (i.e., 17.78 cm), can be accomplished at low cost by a push bench having a push rod and at least two rollers housed in a loop bed, wherein the push rod guide includes at least one guide mechanism having an adjustable guide bore. If the guide bore is matched to each ram at the time of ram replacement, rams with different diameters can be used without problems and therefore without additional expenditure. The mandrel guide proposed here makes it possible to prevent the hollow billet or tube blank from bending in a structurally reliable manner, in particular to prevent or minimize damage to the rollers.

It is also advantageous if the guide mechanism has a preferably openable guide support, on which at least two guide elements are arranged, which can be adjusted by means of an adjusting tool and each have a guide surface for contacting the ejector pin. This makes it possible to fit different push rods in a structurally simple manner.

The adjusting means may be of different kinds, e.g. hydraulic, electric and/or mechanical.

According to another aspect of the invention, the manufacture of seamless metal tubes, especially for medium and large diameters, and for seamless metal tubes with a diameter exceeding 7 inches (i.e. 17.78 cm), can also be achieved at low cost by a push bench having a push rod and at least two rollers placed in a loop bed, wherein the rollers or rolls of the rollers are arranged in the rollers according to a bore direction which is inclined at an angle greater than zero degrees and less than 180 degrees with respect to the mounting direction of the rollers. Thereby, various applications of the drum can be well realized, thereby reducing costs.

In the determination of the angle, the aperture direction on the symmetry line of the roller device is set to a minimum angle, so that the angle can be determined efficiently and meaningfully. For example, a roller with three rollers may have its aperture direction inclined at an angle between 0 and 120 degrees with respect to the mounting direction if a larger or smaller angle makes it impossible to have a new roller for symmetry reasons. Likewise, for the case of two rollers on the drum, the angular range may be between 0 and 180 degrees.

In particular, it is advantageous in this case that one of the drums is provided with four rollers or rolls forming a circular pass of the drum, and that the direction of the bore is inclined at an angle of 22.5 ° with respect to the mounting direction of the drum, whereby, on the one hand, the stretching action and/or frictional engagement and, for the latter, the impact force transmitted by the ram to the billet can be kept at a good level, and, on the other hand, a multiplicity of applications of the respective drum type can be realized, and the costs involved can be reduced as a result. Alternatively, these advantages can also be achieved when at least one of the rollers is provided with three rollers or rolls forming the circular pass of the roller, and the bore direction is inclined at an angle of 30 ° with respect to the mounting direction of the roller. Likewise, the advantages described above can also be achieved for a drum with two rollers or rolls forming the circular pass of the drum, when the aperture direction is inclined at an angle of 45 ° with respect to the mounting direction of the drum.

It has thus been determined that, according to another aspect of the invention, the manufacture of seamless metal tubes, especially for medium and large diameters, and for seamless metal tubes with a diameter exceeding 7 inches (i.e. 17.78 cm), can be realized at low cost by a push bench having a push rod and at least two rollers housed in a ring bed, wherein the rollers or rolls are arranged in the rollers according to a bore direction inclined by an angle of 90 degrees divided by the number N of rollers or rolls per roller, i.e. by 90 °/N, with respect to the mounting direction of the rollers. This makes it possible to achieve a large number of applications of the drum, and thus to reduce costs, since the drums need to be mounted in different mounting directions, in order to arrange the rollers or rolls of each drum in a staggered manner.

Cumulatively or alternatively, the production of seamless metal tubes, in particular for medium and large diameters, and for seamless metal tubes with a diameter of more than 7 inches (i.e. 17.78 cm), can be achieved at low cost by a method for producing metal tubes from a billet in which the billet is first perforated, then drawn in a pipe push bench and then finish-rolled into a tube, wherein the method is characterized in that the perforated billet is drawn on the pipe push bench with a draw ratio of not more than 7, preferably not more than 6. This non-systematic, relatively small draw ratio determines that the load on the pierced billet during drawing is small enough to allow a low cost construction of the push bench.

It is particularly advantageous for the billet to be drawn at a draw ratio of at least 1.2, preferably at least 1.5, during the perforation, which correspondingly increases the draw ratio as a whole.

In particular, the production of seamless metal pipes, in particular for medium and large diameters, and for seamless metal pipes with a diameter of more than 7 inches (i.e. 17.78 cm), can be achieved at low cost by a method for producing a metal pipe from a billet in which the billet is first perforated, then drawn in a push bench and then finish rolled into a pipe, wherein the method is characterized in that the billet is drawn at a draw ratio of at least 1.2, preferably at least 1.5, at the time of perforation and at a draw ratio of not more than 7, preferably not more than 6, on the push bench.

If the relevant stretch ratio lies in such a range, a high degree of flexibility can be achieved in particular during the execution of the method. Furthermore, because of the small stretching performed in the push bench, the rollers can be arranged particularly densely, which results in a compact loop bed and thus in a corresponding cost saving, wherein a part of the stretching process has been transferred from the push bench to the piercer beforehand.

According to a further aspect of the invention, the production of seamless metal pipes, in particular for medium and large diameters, and for seamless metal pipes with a diameter of more than 7 inches (i.e. 17.78 cm), can be realized at low cost by a method for operating a seamless pipe plant with a piercing machine, in particular with a skew rolling mill (e.g. a conical skew rolling mill), a pipe push bench arranged after the piercing machine, and a finishing mill (in particular a stretch reducing mill) arranged after the pipe push bench, wherein for producing the metal pipe from a billet, the billet is first pierced in the piercing machine, then stretched in the pipe push bench and then finish rolled into a pipe in the finishing mill, wherein the method is characterized in that only single lengths are processed and produced.

By processing and manufacturing only a single length, a pipe pusher for seamless pipe equipment can be provided with a short loop bed. It is furthermore advantageous if the latter can be used in particular in conjunction with the abovementioned elongation.

In this case, the production of seamless metal pipes, in particular for medium and large diameters, and for seamless metal pipes with a diameter of more than 7 inches (i.e. 17.78 cm), can be achieved at low cost by a seamless pipe plant with a piercer, in particular with a skew rolling mill (e.g. a conical skew rolling mill), a push bench arranged after the piercer and a finishing mill (in particular a stretch reducing mill) arranged after the push bench, wherein the mills are preferably designed on the basis of a series of bore diameters, and the push bench comprises at least two push rod assemblies with different push rod diameters, wherein at least one set of the seamless pipe plant, in particular the piercer, the push bench and the finishing mill, and all other sets of the seamless pipe plant, is designed for producing seamless metal pipes with a diameter of more than 7 inches (i.e. 17.78 cm) to a length for use, thereby enabling a shorter annular bed on a seamless tube plant.

By processing and producing only a single length, it is possible here to provide a very short loop bed for a push bench for seamless pipe installations, which is correspondingly cost-effective.

It is clear that the above-described seamless tube plant can also be used, if necessary, for producing tubes of smaller diameter, wherein even smaller diameters can easily be achieved in multiples. At diameters exceeding 7 inches (i.e., 17.78 centimeters), the limitation of the apparatus and method of implementation to single lengths has the great disadvantage of being much reduced in weight due to inevitable cutting losses and loss of the end of each string. On the other hand, this possibility makes it possible to operate the device in a smaller diameter, if necessary, in multiple lengths and only in single lengths when the diameter exceeds 7 inches (i.e. 17.78 cm), so that the device can be operated economically in a wider range. Typically, for single lengths, the pipe lengths are between 10.67 and 16.76 meters, depending on the use of the pipe, it is possible to make and provide, for example, drill pipe lengths of between 11.55 and 13.68 meters, casing and tubing lengths of between 10.36 and 14.63 meters, and pipe-pipe lengths of between 10.67 and 13.72 meters or between 13.35 and 16.76 meters.

Obviously, in the production of metal pipes with a diameter exceeding 7 inches (i.e. 17.78 cm), it is sufficient that only one train of seamless pipe plants is limited to a single length, while the other trains retain a correspondingly large capacity. This has correspondingly greater freedom for smaller diameter pipes, when they should be manufactured in multiple lengths. Preferably, at least the piercer, the push bench and the finishing block are dimensioned in such a way that they can only process the work pieces required when manufacturing metal pipes with a diameter exceeding 7 inches (i.e. 17.78 cm) to single lengths. In particular, this means that, for example, for machining workpieces for producing metal pipes with a diameter of more than 7 inches (i.e. 17.78 cm), the rolling mill and the drive capacity, based on the respective weight and force and deformation or elongation, can be designed to be small. Preferably, all the units, such as lifting tools and the like, are designed accordingly, which thus contributes to cost savings.

Furthermore, the production of seamless metal pipes, in particular for medium and large diameters, and for seamless metal pipes with a diameter of more than 7 inches (i.e. 17.78 cm), can be realized at low cost by a seamless pipe plant with a piercing mill, in particular with a cross-rolling mill (e.g. a conical cross-rolling mill), a push bench arranged after the piercing mill and a finishing mill, in particular a stretch-reducing mill, arranged after the push bench, wherein the rolling mill is designed on the basis of a sequence of hole diameters and the push bench comprises at least three push rod assemblies with different push rod diameters, wherein the piercing mill has at least three hole cores with different hole core diameters, and each push rod with a first push rod diameter and each hole core with a first hole diameter correspond to at least one common hole diameter of the hole series.

With a seamless tube plant of this construction, despite the very high variability to be achieved, the push rods can be fitted better in the hollow billet, so that collisions can be achieved more simply, or even avoided, which has a corresponding cost advantage.

Among them, various combinations of the carrier rod and the hole core can be considered, and especially, different rollers can be used according to the hole pattern.

In summary, the invention can be advantageously applied to seamless pipe plants, in particular for the manufacture of seamless pipes greater than 7 inches, with small to medium production capacities.

In addition, the hitherto high space requirements of the (known) push bench can be significantly reduced in suitable applications.

Collisions can also be completely cancelled as required in suitable application variants by means of the above-mentioned technical features or combinations of technical features.

Furthermore, material loss can be greatly reduced by the undercuts otherwise required on perforated billets or tubes.

Preferably, the existing collisions are integrated during the rolling process, so that the existing manufacturing method can be simplified.

In particular, the hitherto long retrofitting times can be significantly shortened cumulatively or alternatively for products with large variations in wall thickness or for seamless pipes.

In addition, the tool change time can be greatly shortened compared to conventional push bench.

Furthermore, compared to the conventional Konti-tube manufacturing method, the MPM-tube manufacturing method and the PQF-tube manufacturing method can reduce the tool requirements and increase the tool life.

In addition, a simplified drive, in particular for hollow billets, and a simplified maintenance method and rolling mill installation are also provided.

It is particularly advantageous that in particular thin-walled or alloyed pipes can be rolled better than in cross-rolling drawing.

At present, it is preferable to perform single-length processing or rolling in rolling. However, the multiple lengths also belong substantially to the field of application of the invention.

Thus, the push bench of the present invention is preferably limited to moderate stretch, thereby reducing the length and size of the push rod. Alternatively, a conical skew rolling mill can be used, with a correspondingly high drawing capacity during the piercing, to ease the work of the push bench.

In order to keep the ring bed as compact as possible, the length of the tube billet can be limited to about 14 to 15 meters.

In addition, four roll stands may be used in the push bench of the present invention to facilitate increased stretching effect.

Cumulatively or alternatively, it is advantageous to use one or more driven starting stands for roll-piercing billets or hollow billets on a mandrel in a push bench, as explained in detail above.

The invention can be realized in a structurally simple manner when the support used with the push bench of the invention is designed as a four-roll support with two driven rolls and two pulling rolls or the like.

Furthermore, it is advantageous, where appropriate, to use a roll bar, on which the hollow billet is rolled, together with the preceding solution. This achieves an increase in the impact force transmitted by the roll bar to the hollow billet, as explained in detail above.

In particular, the rollers in the undriven rollers and/or the outer surface of the hollow billet may be lubricated in order to reduce the impact force.

In addition, the invention also has the following advantages:

by simplifying the drive, prolonging the service life of the tool, simplifying the requirements on the tool and by reducing the control requirements, the method of the invention is more cost-effective for lower production capacities than the PQF method and the MPM method.

In addition, simpler low-alloy tool steels can be used if necessary.

Furthermore, if necessary, chromium-plated core rods, which can cause environmental pollution, can be eliminated.

A simpler machine, such as a peeler, can preferably be used to adjust the mandrel.

Overall, the service life of the bars and rolls is extended, since the rolling mill can be implemented more simply and at lower cost.

It is to be understood that the above-mentioned features and the features of the claims can also be combined, if necessary, in order to achieve corresponding advantages cumulatively.

Drawings

The advantages, objects, and features of the invention are explained in detail below with reference to embodiments illustrated in the accompanying schematic drawings. In the drawings:

figure 1 schematically shows a seamless pipe plant;

FIG. 2 shows a push bench of the seamless pipe plant shown in FIG. 1;

FIG. 3 shows a guide mechanism for the push bench of FIG. 2;

FIG. 4 shows a top view of a roller receiving device with a corresponding transverse conveyor; and

fig. 5 shows a further drum receiving device in a plan view.

Detailed Description

The seamless pipe apparatus 2 shown in fig. 1 includes a piercing mill 64 designed as a tapered skew rolling mill in the present embodiment, a pipe jacking mill 1, and a finishing mill 65 provided as a stretch reducing mill in the present embodiment, wherein a billet 15 is pierced in the piercing mill 64, a pierced billet 16 is hit by the pipe jacking mill 1, and then rolling is completed as a hollow shell 63 in the finishing mill 65.

Here, push bench 1 comprises at least three push rod assemblies (schematically shown in fig. 1) of push rods 3 with different push rod diameters 4, wherein the push rod assemblies may correspond to a sequence of hole diameters 67 (see fig. 1), which in turn correspond to respective piercing mandrels 66 of the piercing mill, and wherein in the schematic illustration of fig. 2 a first push rod 3 with a first push rod diameter 4 of one of the three push rod assemblies is placed on the impinging rolling line 5 of push bench 1. The ram 3 shown is moved along the impact rolling line 5 in an axial impact rolling direction 6 by means of a ram drive, not shown and conventional. In this connection, the ram 3 strikes forward on the strike line 5 with its tip 7 facing forward in the axial strike-rolling direction 6.

On the mandrel 3, a workpiece 14 has been arranged which is obtained by piercing a billet 15 and from which a metal tube (not shown) is to be produced, so that the billet 15 becomes a pierced billet 16 or a pierced hollow billet (not specifically designated), wherein the billet 15 has previously been pierced in a piercing machine (not further shown here) of the seamless tube plant 2 with an inner diameter 17 which is adapted to the mandrel diameter 4.

In addition, to form such a hollow tube core 63, push bench 1 also comprises a ring bed 26 (at least in the present embodiment, a total of four rollers 21, 22, 23, 24 of a first roller assembly 25 arranged in succession on the crash pass line 5, which have been arranged in the ring bed 26 of push bench 1 according to the drawing, here rollers 21, 22, 23, 24 are each arranged in a roller receiver 55 fixed sufficiently firmly in ring bed 26 along the crash pass line, so that rollers 21, 22, 23, 24 located in the roller receiver are able to resist the force exerted by push rods 3.

Each roller 21 to 24 of the first roller assembly 25 has here a roller 27 and/or a roller 28 (only schematically indicated), which can be arranged in the respective roller 21 to 24 in a driven or non-driven or drawn manner, depending on the requirements and application.

In the present exemplary embodiment, at least one roller 28 of the first drum 21 (starting drum) is driven by a drive, not shown in detail here, so that the perforated billet 16 can be pushed by the driven roller 28 in the axial impact rolling direction 6 when it reaches the first drum 21.

These rollers 27 or rolls 28 can be designed with a circular pass (not shown) in each of the cylinders 21 to 24, wherein preferably four rollers 27 or rolls 28 forming a circular pass are provided. As long as at least one of the rollers 21 to 24 is provided with four rollers 27 or rolls 28 forming such a circular pass. In this regard, this particular one of the rollers 21 to 24 may have two drive rollers 28 and two traction rollers 27, while the remaining rollers 22 to 24 comprise only the traction rollers 27.

The length 30 of loop bed 26 is less than 1.3 times the longest workpiece length 31 of workpiece 14 passing through push bench 1 of all the aperture sequences for which push bench 1 is set.

Furthermore, as is shown in particular in fig. 4 and 5, the drums 21 to 24 can be inserted laterally (i.e. from the side 32) into the ring bed 26. The flank 32 is arranged radially next to the impinging rolling line 5, based on the axial impinging rolling direction 6.

Furthermore, push bench 1 comprises at least one further roller assembly 40, which at least in this first embodiment consists of at least four

further rollers

41, 42, 43, 44.

In this case, both the first roller assembly 25 and the further roller assembly 40 can be arranged next to the ring bed 26 of the impact pass line 5, so that the individual rollers 21 to 24 or 41 to 44 can be transferred from the side onto the impact pass line 5 or removed therefrom for replacement without difficulty.

In a particularly simple manner, the two roller assemblies 25 and 40 can be provided in a manner parallel to the striking pass line 5 laterally next to the ring bed 26 by means of a roller changer 50 which can carry the two roller assemblies 25 and 40, so that they can be brought without difficulty into their respective changing positions 51 (indicated here only by way of example) in which the respective roller 21 to 24 or 41 to 44 can be changed.

For this purpose, the roller changer 50 has a first bearing assembly 52 and a second bearing assembly 53, wherein the first bearing assembly 52 and the further bearing assembly 53 are each formed by four roller bearing devices 54 (only exemplarily indicated here).

As long as each of the rollers 21 to 24 and 41 to 44 has its own changing position 51 assigned to it on the roller changer 50.

This means, in turn, that the respective associated change position 51 on the roll changer 50 is arranged laterally next to the loop bed 26 and next to the associated drum receptacle 55 of the loop bed 26.

In order to transfer the individual rollers 21 to 24 or 41 to 44 between the change position 51 on the roller carriage 50 and the roller receptacles 55 on the loop bed 26, a transverse conveyor 74 which is designed accordingly and is not shown in fig. 2 but only in fig. 4 is provided at the push bench 1.

In order to realize the change position 51, the roll changer 50 is equipped with corresponding roll bearing devices 54, which can be of various designs, as long as it is ensured that the associated roll 21 to 24 or 41 to 44 can be reliably held or supported on the roll changer 50.

Push bench 1 of the present embodiment comprises two support assemblies 52 and 53, which are arranged on roller changer 50 parallel to the direction of impact rolling 6 of push bench 1 offset by an offset 60. Therefore, in order to place the bearing assembly 52 or 53, respectively, at the change position 51, the roller changer only has to move the offset 60. Therefore, it is possible to initially place free bearing assemblies 52 for the rollers 21 to 24 in the change position 51 in order to move the rollers 21 to 24 onto the roller changer 50 by means of the transverse conveyor 24. Subsequently, the roller changer 50 is moved by the offset 60 so that the other roller assembly 40 with its rollers 41 to 44 is located in the change position 51 and its rollers 41 to 44 can be introduced into the roller receptacles by the transverse conveyor 74. This makes it possible to carry out the replacement of the individual cylinders 21 to 24 and 41 to 44 very quickly.

Here, the offset 60 is less than the length 30 of the ring bed 26. In particular, offset 60 is smaller than distance 61 between the first 54A and the last 54D roller bearing of either bearing assembly 52 or 53 in the direction of impact rolling 6 of push bench 1, and more particularly smaller than the shorter of distances 62 of two immediately adjacent roller bearings 54 of bearing assemblies 52 and 53. This means that the roll changer 50 can be moved with minimal effort, which is therefore advantageous in terms of time and construction.

Furthermore, the rollers 21 to 24 or 41 to 44 can be prevented well from jumping out in the direction 62 of the transverse conveyor 74 by a locking device 76 (see fig. 5) which acts parallel to the transverse conveyor 74.

In order to allow the rollers 21 to 24 or 41 to 44 located in the roller receptacles 55 to be removed in the event of an overload of the push bench 1, the push bench 1 has or the roller receptacles 55 have an overload protection device 75 which can be opened upwards (i.e. out of the plane of the paper as shown in fig. 2) (see fig. 4 and 5). In this case, overload protection device 75, as shown in fig. 4, has only one roller receptacle 55 which opens upward, so that in the event of an overload of push bench 1, the

respective roller

21, 22, 23, 24, 41, 42, 43 or 44 can be moved upward. In contrast, the overload protection 75 shown in fig. 5 comprises an overload bar 77 which, in normal operation, defines a holding of the

respective roller

21, 22, 23, 24, 41, 42, 43 or 44 and which only opens upwards as soon as a predefined overload has occurred.

In addition, push bench 1 includes a push rod guide 71 that includes at least one guide mechanism 68 having an adjustable guide hole pattern. As shown in particular in fig. 3, the guide device 68 has a guide support 70, in which two guide elements 71 designed as rollers are arranged, which can be adjusted by means of an adjusting tool 72 to match different ram diameters 4 or, if appropriate, to allow the passage of the pierced billet 16. The guide bracket 70 can be opened for maintenance purposes and for installation purposes by means of an opening tool 73.

In particular, a method of producing a metal pipe from billet 15 can be carried out very efficiently with such a seamless pipe plant 2 comprising pipe push bench 1, wherein billet 15 is first pierced in piercer 64 located before pipe push bench 1, wherein pierced billet 16 is then drawn into hollow shell 63 in pipe push bench 1, and then rolled into a metal pipe in finishing mill 65 located after pipe push bench 1.

Here, perforated billet 16 on push bench 1 is first pushed by rollers 28 arranged in first drum 21 or 41 of push bench 1, wherein a friction fit is created between push rod 3 of push bench 1 and perforated billet 16 by the rollers of first drum 21 or 41 of push bench 1.

The perforated billet 16 is preferably rolled on the mandrel 3.

It is particularly advantageous that billet 15 is pierced during piercing into a pierced billet 16 having a constant and continuous inner diameter 17, which is then fed into push bench 1 or ring bed 26 without collision.

Alternatively, the perforated billet 16 on the push bench 1 can be hit by rollers 27 and, if necessary, also by rollers 28.

Preferably, the outer surface 18 of the billet 15 or the perforated billet 16 is lubricated after the first roller 21, since no further rolling is provided for pushing. In an alternative embodiment, the lubrication can also be carried out before the first cylinder 21, if the position of the contact rolls 28 is left free in the circumferential direction. These positions can also be lubricated as soon as the rolls 28 no longer need to be driven.

Obviously, the above embodiments only relate to the technical solution of the push bench or seamless pipe equipment of the present invention. However, the technical solution of the present invention is not limited to these examples.

The mandrel and bore assemblies of piercer 64 and push bench 1 and the corresponding series of bores 67 are in this case coordinated with one another in such a way that the elongation at piercing is between 1.8 and 2.2 and the elongation at impact is between 4.5 and 5.5. Similarly, only a single length may be made in the seamless pipe manufacturing facility 2.

List of reference numerals:

1 push bench

2 seamless pipe installation

3 ejector pin

4 diameter of ejector pin

5-impact rolling line

6 axial direction of impact or rolling

7 top part

14 workpiece

15 billet

16-perforated billet

17 inner diameter

18 outer surface

21 first roller of first roller assembly

22 second roller of the first roller assembly

23 third roller of the first roller assembly

24 fourth roller of first roller assembly

25 first roller assembly

26-ring bed

27 roller

28 roll

30 length

31 length of workpiece

32 side surface

40 first roller of another roller assembly

41 second roller of another roller assembly

42 third roller of another roller assembly

43 third roller of another roller assembly

44 fourth roller of another roller assembly

50 roll changing vehicle

51 exchange position

52 first support assembly

53 alternative support Assembly

54 roller supporting device

54A first roller supporting device

54D last roller support device

55 roller accommodating device

Offset of 60

Distance 61

62 shorter distance

63 hollow shell

64 perforating machine

65 finishing mill

66-hole core

67 pore size sequence

68 guide mechanism

69 guide surface (exemplary label)

70 guide bracket

71 guide device

72 adjustment tool

73 opening tool

74 transverse conveying device

75 overload protection device

76 locking device

77 overload beam

Claims

1. Method for producing a metal tube from a billet (15), wherein the billet (15) is first pierced, then drawn in a push bench (1), and then finish rolled into a tube, characterized in that the billet (15) has a constant and continuous inner diameter (17) at the time of piercing and is subsequently fed into the push bench (1) free of collisions; and is

(i) The pierced billet (16) is first pushed on the pipe push bench (1) by at least one roll (28) arranged in the rollers (21, 22, 23, 24, 41, 42, 43, 44) of the pipe push bench (1);

(ii) at least the rollers (27) of the first rollers (21, 22, 23, 24, 41, 42, 43, 44) of the push bench (1) effect a friction fit between the push rod (3) of the push bench (1) and the pierced billet (16);

(iii) the perforated billet (16) loosely arranged on the push rod (3) is collided on the push rod (1) and/or rolled on the push rod (3) at least by rollers (27) of rollers (21, 22, 23, 24, 41, 42, 43, 44) of the push rod (1) before being stretched on the push rod (1).

2. Method according to claim 1, characterized in that the pierced billet (16) is collided on the push bench (1) at least by rollers (27) of the first rollers (21, 41) of the push bench (1) and/or rolled on the push rod (3).

3. A method according to claim 1, characterized in that the outer surface (18) of the drawn roller (27) and/or the perforated billet (16) is lubricated before it passes the drawn roller (27).

4. A method according to claim 3, characterized in that only the entrained rollers (27) of the rollers (21, 22, 23, 24, 41, 42, 43, 44) in which no rollers (28) are driven, and/or the outer surface (18) of the perforated billet (16), are lubricated before it passes through such rollers (21, 22, 23, 24, 41, 42, 43, 44).

5. A method according to claim 4, characterized in that only the rollers (27) of the rollers (21, 22, 23, 24, 41, 42, 43, 44) having only the entrained rollers (27), and/or the outer surface (18) of the perforated billet (16) are lubricated before it passes through such rollers (21, 22, 23, 24, 41, 42, 43, 44).

6. Method according to any of claims 1 to 5, characterized in that the ram (3) of the push bench (1) is hit through the loop bed of the push bench (1) at an ascending impact speed and/or at an impact speed of not more than 4 m/s.

7. A method according to any one of claims 1 to 5, characterized in that the perforated billet (16), at least until it reaches the first roller (21, 41) of the push bench (1) and comes into contact with the rollers (27) and/or the rolling rollers (28) of said rollers (21, 41), is placed on said ejector pin (3) by means of a separate positioning device and/or is conveyed in the direction (6) towards said rollers (21, 41) by a separate push-in aid.

8. A method according to claim 1, characterized in that the perforated billet (16) is drawn on the push bench (1) at a draw ratio not exceeding 7.

9. A method according to claim 1, characterized in that the perforated billet (16) is drawn on the push bench (1) at a draw ratio not exceeding 6.

10. Method according to claim 1, characterized in that not only the push bench (1) but also all the units connected before and after the push bench (1) are set for single lengths only.

11. Method according to claim 1, using a piercing mill, a push bench (1) arranged after the piercing mill and a finishing mill arranged after the push bench (1), wherein for producing metal pipes with a diameter of more than 17.78 cm from the billet (15), the billet (15) is first pierced in the piercing mill, then drawn in the push bench (1) and then finish rolled into a pipe in the finishing mill.

12. Method according to any of claims 8 to 11, characterized in that the billet (15) is drawn at a draw ratio of at least 1.2 when it is perforated before being processed on the push bench (1).

13. Method according to any of claims 8 to 11, characterized in that the billet (15) is drawn at a draw ratio of at least 1.5 when it is perforated before being processed on the push bench (1).

14. Method according to claim 11, characterized in that the piercer is a cross-rolling piercer and/or the finishing mill is a stretch-reducing mill.

15. The method according to claim 11, characterized in that the piercer is a conical skew rolling mill and/or the finishing mill is a stretch reducing mill.

16. Push bench (1) with a push rod (3) and at least two rollers (21, 22, 23, 24) placed in a loop bed (26), characterized in that,

(i) at least a first roller (21, 41) in the striking direction (6) of the ram (3) is provided with at least one drivable roller (28); and

(ii) the first roller (21, 41) is provided with at least a roller (27) for friction fit between the ejector pin (3) and the pierced billet (16); and/or

(iii) The push bench (1) comprises positioning means for placing the perforated billet (16) on the push rod (3) and/or pushing means for conveying the perforated billet (16) on the push rod (3) in a direction (6) towards the rollers (21, 22, 23, 24).

17. Push bench (1) according to claim 16, characterized in that at least one roller (21, 22, 23, 24, 41, 42, 43, 44) is provided with four rollers (27) or rolls (28) forming a circular pass of the roller (21, 22, 23, 24, 41, 42, 43, 44).

18. Push bench (1) according to claim 17, characterized in that the rollers (21, 22, 23, 24, 41, 42, 43, 44) are provided with two driven rollers (28) and two traction rollers (27) or four traction rollers (27).

19. Push bench (1) according to claim 16, characterized in that the rollers (21, 22, 23, 24, 41, 42, 43, 44) can be loaded laterally into the loop bed (26).

20. Push bench (1) according to claim 19, characterized in that the loop bed (26) has at least two laterally open roller receiving devices (55).

21. Push bench (1) according to claim 20, characterised in that a transverse conveyor (74) is provided between the roller receiving devices (55) and the change position (51) on the side of the loop bed (26) depending on the roller receiving devices (55).

22. Push bench (1) according to claim 21, characterised by a roller change carriage (50) which is arranged at the side of the loop bed (26) and which is movable parallel to the impact direction (6) of the push bench (1), wherein the roller change carriage (50) is provided with at least two roller support means (54) which are arranged at intervals on the roller change carriage (50) according to the relevant change position (51).

23. Push bench (1) according to claim 22, characterised in that the roller change carriage (50) is provided with at least two sets of two roller bearing arrangements (54), of which two roller bearing arrangements (55) belonging to the first bearing assembly (52) are arranged at intervals on the roller change carriage (50) according to the associated change position (51), and two roller bearing arrangements (54) belonging to the second bearing assembly (53) are arranged at intervals on the roller change carriage (50) according to the associated change position (51), wherein the two bearing assemblies (52, 53) are arranged on the roller change carriage (50) offset by an offset (60) parallel to the impact direction (6) of the push bench (1).

24. Push bench (1) according to claim 23, characterized in that the offset (60) is smaller than the length (30) of the loop bed (26).

25. Push bench (1) according to claim 23, characterized in that the offset (60) is smaller than the distance between the first support means (54A) and the last support means (54D) of any one support assembly (52, 53) in the impact direction (6) of the push bench (1).

26. Push bench (1) according to claim 23, characterized in that the offset (60) is smaller than the distance (62) of two adjacent support means (54) of any one support assembly (52, 53).

27. Push bench (1) according to one of claims 19 to 26, characterised in that at least one roller receptacle (55) has an upwardly openable overload protection (75), by means of which the rollers (21, 22, 23, 24, 41, 42, 43, 44) located in the roller receptacle (55) can be moved out upwardly in the event of an overload of the push bench (1), and/or a locking device (76) acting parallel to the transverse conveyor (74), which prevents the rollers (21, 22, 23, 24, 41, 42, 43, 44) from moving out in the direction of the transverse conveyor (74).