DE102014101151B4 - Process for forging, in particular stretch forging, of metal workpieces - Google Patents

Abstract

The invention relates to a method for forging, in particular stretch forging, metal workpieces, comprising the following method steps: a1) in one forging step each, longitudinal rolling of a workpiece (3) with at least one pair of rolling tools, the two rolling tools of which rotate in opposite directions of rotation (D11 and D21 or D12 and D22) are each rotated around an associated axis of rotation (A1, A2), as a result of which the workpiece (3) is formed between the rolling tools and is moved in a feed direction (VR, -VR) resulting from the direction of rotation,b1) in a first feeding step a first workpiece (3) to a first pair of rolling tools (11 and 21 or 12 and 22) on a first working side (51) by means of a first gripping device (5), c1) carrying out a forging step according to feature a1) with the first workpiece (3) , wherein the direction of rotation (D11, D21) of the two rolling tools (11 and 21 or 12 and 22) is set such that the feed direction (VR) of the workpiece (3) from the first working side (51) to a second working side (52) of the pair of rolling tools (11 and 21 or 12 and 22) which is arranged away from the first working side (51), and wherein the first gripping device (5) during at least a portion of the forging step of the feed movement of the first workpiece (3) in follows the feed direction (VR),d1) in a transfer step during or after the forging step, transferring the first workpiece (3) from the first gripping device (5), which is arranged or working on the first working side (51), to a second gripping device ( 6) which is arranged or works on the second working side (51) and grips the first workpiece (3), the first gripping device (5) holding the first

Description

The invention relates to a method for forging, in particular stretch forging, of metal workpieces and a forge-rolling device for carrying out the method.

The forging of metallic materials such as iron or steel materials or aluminum materials is usually carried out at elevated forming temperatures in order to achieve the formability and flowability of the material required for forming. The temperatures that usually occur during forging are between 550°C and 750°C for warm forging and above 900°C for so-called hot forging.

For forging metal workpieces from an initial shape into a desired intermediate shape (semi-finished product, preforms) or final shape (finished product, finished shapes), rolling processes are known, among many other processes, which are counted among the pressure forming processes. During rolling, the workpiece (rolled stock) is placed in the roll gap between two rotating rolls or tools arranged on them and its shape is changed by exerting a forming pressure through the rotating rolls or tools. In the profile rolling process, tool profiles are arranged on the circumference of the rolls, which enable the corresponding profiles to be produced in the workpiece. During flat rolling, the cylindrical or conical outer surfaces of the rolls act directly on the workpiece. A work area with a pair of rollers or just a pair of tools is also referred to as a pass or caliber.

With regard to the relative movement of the tools or rollers on the one hand and the workpiece on the other hand, rolling processes are divided into longitudinal rolling, cross rolling and cross rolling.

During longitudinal rolling, the workpiece is moved perpendicularly to the axes of rotation of the rolls in a translational movement and usually without rotating through the roll gap during its forming. The two rollers rotate in opposite directions and thus move with their opposite roller edges at the nip tangentially in the same direction, which corresponds to the feed direction of the workpiece. Longitudinal rolling processes include stretch rolling, which is a stretch forging process in which a blank is stretched or stretched in length between rotating stretching tool segments on the rolls, thereby reducing its cross section.

During cross rolling, the workpiece does not translate in relation to the rollers or their axes of rotation, but only rotates around its own axis. The rollers rotate here in the same direction of rotation and thus move with their opposite roller edges at the nip tangentially in the opposite direction, whereby a torque and a rotational movement is transmitted to the workpiece.

A combination of longitudinal rolling and cross rolling is referred to as skew rolling. The rollers are usually at an angle to each other and to the workpiece, which is then moved in a translatory and rotary manner at the same time.

The German patent application DE 10 2013 100 302 A1 The same applicant describes a method for forging metal workpieces, which comprises the following method steps: a) in one forging step, longitudinal rolling of a workpiece between at least one pair of tool segments of two tool segments, one tool segment on a first roll and the other tool segment on a second rollers are provided, with the rollers being rotated in mutually opposite directions of rotation about an associated axis of rotation and the workpiece being thereby moved between the tool segments in a feed direction resulting from the sense of rotation of the rollers, b) in a first feeding step, feeding a first workpiece a first working side of the rolls, c) carrying out a first forging step according to step a) with the first workpiece, d) in a first removal step, removing the first workpiece, preferably on the first working side, e) in a second feeding step, feeding a second workpiece a second working side of the rolls, preferably arranged opposite to the first working side, f) carrying out a second forging step according to step a) with the second workpiece, g) in a second removal step, removing the second workpiece, preferably on the second working side, h ) wherein the directions of rotation of the two rolls are adjusted differently in the two forging steps, so that the feed direction of the first workpiece in the first forging step is opposite to the feed direction of the second workpiece in the second forging step.

The German patent application DE 10 2014 101 150 A1 , also from the same applicant, discloses a method for forging, in particular stretch forging, of metallic workpieces comprising the following method steps: a1) longitudinal rolling of a workpiece in one forging step each with at least one pair of rolling tools, the two rolling tools of which are each rotated in opposite directions of rotation about an associated axis of rotation, as a result of which the workpiece is formed between the rolling tools and is moved in a feed direction resulting from the direction of rotation, b1) in a first feeding step, feeding a first workpiece to a first pair of rolling tools on a first working side of the pair of rolling tools by means of a first gripping device, c1) carrying out a first forging step according to step a1) with the first workpiece, the direction of rotation of the two rolling tools being set in such a way that the feed direction of the workpiece moves from the first working side to one second working side of the first pair of rolling tools, which is arranged facing away from the first working side, and wherein the first gripping device follows the feed movement of the first workpiece in the feed direction during the forging step, d1) in a second feeding step, feeding the first workpiece to a second pair of rolling tools , which is arranged next to the first pair of rolling tools and/or which has a first working side that is common to the first pair of rolling tools and a second working side that is common to the first pair of rolling tools, by means of the first gripping device, with the rolling tools in particular not being moved apart during the second feed step, but the first workpiece and/or the first gripping device is/are moved or handled completely in a nip between the rolls, and e1) performing a second forging step according to step a1) with the first workpiece in the second pair of rolling tools, the first gripping device being used during the forging step following the feeding movement of the first workpiece in the feeding direction, and a forge-rolling apparatus for performing such a method.

The German patent DE 103 19 258 B4 describes a cross wedge rolling machine that can also be used for stretching processes, in that the direction of rotation of the rolls of this rolling machine can be reversed, so that either the roll rotation can be adjusted in the same direction for use as a cross wedge rolling machine or the roll rotation can be set in the opposite direction for use as a stretching rolling machine. It is also possible to reverse the direction of rotation of the rollers in phases during a forming process of a workpiece.

The Japanese patent application JP H02-182 339 A in the associated Patent Abstract of Japan discloses a stretching method in which the rollers can be driven in both directions of rotation in order to process the same workpiece a second time in the same tool, but with the direction of rotation reversed.

The present invention is based on the object of specifying a method for forging, in particular stretch forging, of metal workpieces and a forging-rolling device with which short cycle times can be achieved.

This object is achieved with the features of patent claim 1 with regard to the method and with the features of claim 11 with regard to the forging-rolling device. Advantageous configurations, developments and applications according to the invention result from the patent claims dependent on patent claim 1 or patent claim 11 .

• a1) in jeweils einem Schmiedeschritt Längswalzen eines Werkstücks mit wenigstens einem Walzwerkzeugpaar, dessen beide Walzwerkzeuge in zueinander entgegengesetztem Drehsinn um jeweils eine zugehörige Drehachse rotiert werden, wodurch das Werkstück zwischen den Walzwerkzeugen umgeformt und in einer sich aus dem Drehsinn ergebenden Vorschubrichtung bewegt wird,
• b1) in einem ersten Zuführschritt Zuführen eines ersten Werkstücks zu einem ersten Walzwerkzeugpaar an einer ersten Arbeitsseite mittels einer ersten Greifeinrichtung,
• c1) Durchführen eines Schmiedeschritts gemäß Merkmal a1) mit dem ersten Werkstück, wobei der Drehsinn der beiden Walzwerkzeuge derart eingestellt wird, dass die Vorschubrichtung des Werkstücks von der ersten Arbeitsseite zu einer zweiten Arbeitsseite des Walzwerkzeugpaares, die von der ersten Arbeitsseite abgewandt angeordnet ist, gerichtet ist, und wobei die erste Greifeinrichtung während zumindest eines Abschnittes des Schmiedeschrittes der Vorschubbewegung des ersten Werkstücks in der Vorschubrichtung folgt,
• d1) in einem Übergabeschritt während oder nach dem Schmiedeschritt Übergeben des ersten Werkstücks von der ersten Greifeinrichtung, die an der ersten Arbeitsseite angeordnet ist oder arbeitet, an eine zweite Greifeinrichtung, die an der zweiten Arbeitsseite angeordnet ist oder arbeitet und das erste Werkstück ergreift, wobei die erste Greifeinrichtung das erste Werkstück zeitgleich mit dem Ergreifen durch die zweite Greifeinrichtung oder zeitverzögert loslässt.

The method for forging, in particular stretch forging, of metallic workpieces according to claim 1 comprises the following method steps:

• a1) in one forging step, longitudinal rolling of a workpiece with at least one pair of rolling tools, the two rolling tools of which are rotated in opposite directions to one another about an associated axis of rotation, as a result of which the workpiece is formed between the rolling tools and moved in a feed direction resulting from the direction of rotation,
• b1) in a first feeding step, feeding a first workpiece to a first pair of rolling tools on a first working side by means of a first gripping device,
• c1) Carrying out a forging step according to feature a1) with the first workpiece, the direction of rotation of the two rolling tools being set in such a way that the feed direction of the workpiece is directed from the first working side to a second working side of the pair of rolling tools, which is arranged away from the first working side and wherein the first gripping device follows the feed movement of the first workpiece in the feed direction during at least a portion of the forging step,
• d1) in a transfer step during or after the forging step, transferring the first workpiece from the first gripping device, which is arranged or works on the first working side, to a second gripping device, which is arranged or works on the second working side and grips the first workpiece, wherein the first gripping device the first workpiece at the same time as the gripping by the releases the second gripping device or with a time delay.

By transferring the workpiece from the first to the second gripping device, the first gripping device is relieved of the further processing of the first workpiece and is free to optionally grip a second workpiece and feed it to the rolling tool. In this way, forging rolling production is not slowed down by the fact that all handling, for example including loading and unloading the workpiece, is carried out by one and the same gripping device during rolling and the rolling tool is temporarily stopped to wait for the next workpiece to be fed in. This means that cycle times can be shortened during rolling, which leads to higher production outputs. Furthermore, the arrangement of the two gripping devices on opposite working sides has the advantage that the workpieces are guided in a continuous line and that the feed and removal paths can be kept short. This also leads to particularly short cycle times.

In the forging step itself, the workpiece is longitudinally rolled by the at least one pair of tools, the two rolling tools of which are each rotated in opposite directions about an associated axis of rotation. The rotary movements of the two rollers are designed in such a way that the workpiece is formed between the rolling tools and is moved in a feed direction resulting from the direction of rotation from a first working side to a second working side of the pair of rolling tools facing away from the first working side. Advantageously, the speeds of rotation are adjusted so that the respective surfaces of the rolling tools of the pair of rolling tools between which the workpiece is moved have the same tangential speeds.

In a first feeding step, the first workpiece is first fed to a first pair of rolling tools on a first working side by means of a first gripping device which is arranged on the first working side or works there. For this purpose, the first gripping device can fetch the first workpiece, for example, from a conveyor or feed device or have already brought it with it from a previous processing step. In particular, the first gripping device picked up the first workpiece from a heating furnace in which the workpiece had been brought to the forging temperature. After the feeding of the first workpiece, the movement proceeds to the forging step, wherein the first gripping device continues to grip the first workpiece and follows the feed movement of the first workpiece in the feed direction during the forging process.

During or after the forging step, the first workpiece is transferred from the first gripping device to the second gripping device located or operating at the second work site, the second gripping device gripping the first workpiece and the first gripping device releasing the first workpiece. The release can take place at the same time as the gripping, but it is also conceivable that the first workpiece, especially if it is an already very thin-rolled part or a long part, is guided by both gripping devices for an overlapping time range and both gripping devices of the feed movement of the first Workpiece follow equally.

An advantageous embodiment of the invention provides that at least one second pair of rolling tools is provided, which is arranged next to the first pair of rolling tools and/or which has a first working side common to the first pair of rolling tools and a second working side common to the first pair of rolling tools. With this arrangement, in a second feeding step, after the first forging step in the first pair of roll tools and the first transfer step, the second gripping device feeds the first work piece to the second pair of roll tools on the second working side, and a second forging step is performed in an analogous manner to the first forging step with the first work piece in the second pair of rolling tools, the direction of rotation of the two rolling tools of the second pair of rolling tools being set in such a way that the feed direction of the workpiece is directed from the second working side to the first working side. In this case, during at least a portion of the second forging step, the second gripping device follows the feed movement of the first workpiece in the feed direction until the first workpiece is transferred again from the second gripping device to the first gripping device, which is carried out during or after the second forging step. This transfer step can also be accompanied by the second gripping device releasing the first workpiece at the same time or with a time delay. Such a change in the direction of rotation of the rollers and the associated reverse feed direction for the first tool from the second to the first working side in this second forging step means that the first workpiece can be further machined without a significant time delay. This effect can be further optimized by a suitable arrangement of the second pair of rolling tools on the roll circumference, for example by already using this in an initial Position is ready when the second gripping device starts feeding the first workpiece. Particularly short transport routes for the first workpiece and avoiding a delay in the start of the second forging step not only lead to particularly high cycle rates, but also to the fact that the workpiece hardly cools down between the forging steps, so that the initial temperature at the beginning of the sequence of forging processes does not need to be set excessively high.

A particularly high cycle rate can be set by feeding a second workpiece to at least one pair of rolling tools, preferably the first pair of rolling tools, on the second working side, preferably from the second gripping device, in a further feeding step, preferably after the second transfer step for the first workpiece and a forging step is carried out with the second workpiece, the direction of rotation of the two rolling tools being adjusted in such a way that the feed direction of the second workpiece is directed from the second working side to the first working side. Here, too, the second gripping device follows the feed movement of the second workpiece during at least one section of the forging step, while guiding it. Similar to the above-mentioned embodiment as with the first workpiece, the second workpiece is also transferred from the second gripping device to the first gripping device, which is ready accordingly, in a transfer step during or after the forging step, with the second workpiece also being released with a time delay by the transferring gripping device can be set. With this even further optimized production method, the feeding of the second workpiece and removal of the first workpiece are essentially simultaneous, which also means that the gripping devices are essentially constantly in motion and are also particularly well positioned for hand-in-hand working are matched.

Depending on the required processing of the workpieces, at least a third pair of rolling tools can also be provided on the rollers and at least one further forging process can be provided in the above-mentioned manner, if necessary with another change of direction of rotation with further transfer of the respective workpiece to the respective other gripping device. After its last forging step, the corresponding workpiece is removed from the pair of rolling tools performing this forging step, this removal step advantageously being carried out by the gripping device located or working on the working side towards which the movement of the workpiece is directed due to the feed direction associated with this last forging step .

A particularly high cycle rate can also be beneficial if the rollers are not moved apart to remove the workpiece after the respective forging step. This is also not absolutely necessary due to the above measures with the respective transfers of the workpiece to the respective other gripping device and due to the favorable arrangement of the rolling tools on the rolls. Exactly such a moving apart of the rolls leads to a significant delay in the processing of the workpiece and the method according to the invention consequently also leads to a significant saving in forging time. Instead, the workpieces are moved completely out of the intermediate space or tool gap in the respective feed direction and can then be transported further by the respective gripping device or handled in some way.

Provision can be made for the sequence of method steps described to be carried out multiple times in succession with different successive workpieces. This is then ensured by the corresponding movements and manipulations of the gripping devices.

Particularly short feed and removal paths with correspondingly short forging times can also be achieved by carrying out these handling steps along a workpiece plane that passes through a roller gap or gap between the rollers, perpendicular to a plane running through the two roller axes and/or essentially tangentially to runs along the roll shell surfaces.

The previously mentioned embodiments of the invention are all based on the assumption that the gripping device holding the workpiece during the respective forging process follows the workpiece, ie “pushes” the workpiece into the rolling tool. However, an often cheaper variant provides that the holding gripping device runs ahead of the workpiece in the feed direction, ie the workpiece is “pulled out” of the rolling tool, so to speak. However, "pushing in" or "pulling out" should not be understood to mean that the guiding movement of the gripping device causes tension to be applied to the workpiece in any way; this expression is only intended to illustrate the trailing or forward movement of the gripping device . Rather, the feed movement through the pair of rolling tools and the handling movement of the gripping device are of this type coordinated with each other so that the workpiece remains stress-free.

This case of the preceding gripping device differs from the previously described embodiment in that the transfer step with the transfer of the first workpiece from the first gripping device to the second gripping device already takes place before the first forging step, so that the second gripping device takes over the management of the workpiece during the forging step and consequently runs ahead of the first workpiece. The first gripping device initially only ensures that the first workpiece is made available for collection by the second gripping device. However, if a second forging step follows with the help of a second pair of rolling tools with the rollers rotating in the opposite direction, the first gripping device takes over holding the first workpiece during this second forging step after it has taken over the first workpiece from the second gripping device - again before this forging step has, the second gripping device being responsible in this case for providing the first workpiece to the second pair of rolling tools after removal from the first pair of rolling tools. Otherwise, the forging itself takes place in a manner analogous to holding and guiding during forging by the respective other gripping device. In the case of a time-optimized processing of a second workpiece, the manner of handling by the two gripping devices is also provided in an analogous manner.

A forging rolling device suitable for carrying out at least parts of the above-mentioned method steps comprises at least one pair of rolls with two rolls that can each be rotated about a roll axis and reversed in the direction of rotation and a first gripping device arranged or working on a first working side of the rolls for gripping and moving and/or for removal and/or for providing a first workpiece and a second gripping device arranged or operating on a second working side of the rollers for gripping and moving and/or for removing and/or for providing a second workpiece. Such a forging-rolling device is suitable for setting a lower overall clock rate in the forging process of workpieces by preferably at least partially simultaneous and/or parallel handling of the two workpieces.

Each of the two rolls of the pair of rolls can be fitted with two tool segments, with each tool segment preferably extending around the associated roll axis by a segment angle of less than 180° and/or the two tool segments being on different halves of the roll with respect to a central plane of the roll containing the roll axis roller are arranged.

Preferably, one rolling tool of the first pair of rolling tools is provided on a first roll and the other rolling tool is provided on a second roll. In the same way, one rolling tool of the second pair of rolling tools can also be provided on the first roll and the other rolling tool of the second pair of rolling tools can be provided on the second roll.

• 1 eine Schmiedewalzvorrichtung mit einer Schmiedewalzmaschine mit mehreren Walzwerkzeugen und mit zwei an entgegen gesetzten Arbeitsseiten der Walzwerkzeuge angeordneten und arbeitenden Handhabungsgeräten mit Greifeinrichtungen in einer Draufsicht von oben,
• 2 in einem ersten Zuführschritt das Zuführen eines von der ersten Greifeinrichtung gegriffenen erwärmten ersten Schmiede-Werkstücks von einer ersten Arbeitsseite zu einem gegenläufig rotierenden ersten Walzwerkzeugsegmentpaar eines ersten Walzwerkzeugs der Schmiedewalzmaschine gemäß 1, in einer teilweise geschnittenen seitlichen Ansicht,
• 3 in einem auf den Zuführschritt gemäß 2 folgenden ersten Schmiedeschritt das Walzen des ersten Schmiede-Werkstücks durch das erste Walzwerkzeugsegmentpaar des ersten Walzwerkzeugs der beiden gegenläufig rotierenden Walzen in einem Zwischenstadium des Schmiedeschritts, in dem die erste Greifeinrichtung das erste Schmiede-Werkstück noch greift, die zweite Greifeinrichtung aber noch nicht greift, in einer teilweise geschnittenen seitlichen Ansicht,
• 4 das Walzen des ersten Schmiede-Werkstücks durch das erste Walzwerkzeugsegmentpaar des ersten Walzwerkzeugs in einem gegenüber 3 fortgeschrittenen Stadium des ersten Schmiedeschritts, in dem die erste Greifeinrichtung das erste Schmiede-Werkstück losgelassen hat und die zweite Greifeinrichtung das erste Schmiede-Werkstück greift, in einer teilweise geschnittenen seitlichen Ansicht,
• 5 das Walzen des ersten Schmiede-Werkstücks durch das erste Walzwerkzeugsegmentpaar des ersten Walzwerkzeugs in einem Endstadium des ersten Schmiedeschritts, kurz bevor das Schmiede-Werkstück das Walzwerkzeugsegmentpaar verlässt, wobei die zweite Greifeinrichtung das erste Schmiede-Werkstück weiterhin greift, in einer teilweise geschnittenen seitlichen Ansicht,
• 6 in einem zweiten Zuführschritt das Zuführen eines von der zweiten Greifeinrichtung gegriffenen erwärmten ersten Schmiede-Werkstücks von einer zweiten Arbeitsseite zu einem gegenläufig rotierenden ersten Walzwerkzeugsegmentpaar eines zweiten Walzenwerkzeugs der Schmiedewalzmaschine gemäß 1, in einer teilweise geschnittenen seitlichen Ansicht,
• 7 in einem auf den Zuführschritt gemäß 6 folgenden zweiten Schmiedeschritt das Walzen des ersten Schmiede-Werkstücks durch das erste Walzwerkzeugsegmentpaar des zweiten Walzwerkzeugs der beiden gegenläufig rotierenden Walzen in einem Zwischenstadium des zweiten Schmiedeschritts, in dem die zweite Greifeinrichtung das erste Schmiede-Werkstück noch greift, die erste Greifeinrichtung aber noch nicht greift, in einer teilweise geschnittenen seitlichen Ansicht,
• 8 das Walzen des ersten Schmiede-Werkstücks durch das erste Walzwerkzeugsegmentpaar des zweiten Walzwerkzeugs in einem gegenüber 7 fortgeschrittenen Stadium des zweiten Schmiedeschritts, in dem die erste Greifeinrichtung das erste Schmiede-Werkstück bereits ergriffen hat und die zweite Greifeinrichtung das erste Schmiede-Werkstück noch immer greift, in einer teilweise geschnittenen seitlichen Ansicht,
• 9 das Walzen des ersten Schmiede-Werkstücks durch das erste Walzwerkzeugsegmentpaar des zweiten Walzwerkzeugs in einem Endstadium des zweiten Schmiedeschritts, kurz bevor das Schmiede-Werkstück das zweite Walzwerkzeugsegmentpaar verlässt, in dem die zweite Greifeinrichtung das erste Schmiede-Werkstück losgelassen hat und die erste Greifeinrichtung das erste Schmiede-Werkstück weiterhin greift, in einer teilweise geschnittenen seitlichen Ansicht, und
• 10 eine zweites Ausführungsbeispiel analog 2, jedoch mit abweichender Funktion der Greifeinrichtungen,

jeweils schematisch dargestellt. Einander entsprechende Teile und Größen sind in den 1 bis 10 mit denselben Bezugszeichen versehen.The invention is explained in more detail below using exemplary embodiments. Reference is also made to the drawings, which show:

• 1 a forging-rolling device with a forging-rolling machine with several rolling tools and with two handling devices with gripping devices arranged and working on opposite working sides of the rolling tools in a plan view from above,
• 2 in a first feeding step, feeding a heated first forging workpiece gripped by the first gripping device from a first working side to a counter-rotating first rolling die segment pair of a first rolling die of the forging rolling machine according to 1 , in a partially sectioned side view,
• 3 in accordance with the feeding step 2 following first forging step, the rolling of the first forged workpiece by the first rolling tool segment pair of the first rolling tool of the two counter-rotating rolls in an intermediate stage of the forging step, in which the first gripping device still grips the first forged workpiece, but the second gripping device does not yet grip, in a partially sectioned side view,
• 4 rolling the first forging by the first pair of rolling die segments of the first rolling die in a face-to-face relationship 3 advanced stage of the first forging step, in which the first gripping device has released the first forging workpiece and the second gripping device is gripping the first forging workpiece, in a partially sectioned side view,
• 5 rolling the first forging by the first pair of rolling die segments of the first rolling die in a final stage of the first forging step just before the forging leaves the rolling mill leaving the pair of tool segments, with the second gripping device continuing to grip the first forged workpiece, in a partially sectioned side view,
• 6 in a second feeding step, feeding a heated first forging workpiece gripped by the second gripping device from a second working side to a counter-rotating first rolling die segment pair of a second rolling die according to the forging rolling machine 1 , in a partially sectioned side view,
• 7 in accordance with the feeding step 6 following second forging step, the rolling of the first forged workpiece by the first rolling tool segment pair of the second rolling tool of the two counter-rotating rolls in an intermediate stage of the second forging step, in which the second gripping device still grips the first forged workpiece, but the first gripping device does not yet grip, in a partially sectioned side view,
• 8th rolling the first forging by the first pair of rolling die segments of the second rolling die in an opposite manner 7 advanced stage of the second forging step, in which the first gripping device has already gripped the first forging workpiece and the second gripping device is still gripping the first forging workpiece, in a partially sectioned side view,
• 9 rolling the first forging workpiece by the first pair of rolling die segments of the second rolling die in a final stage of the second forging step just before the forging workpiece leaves the second pair of rolling die segments, in which the second gripping device has released the first forging workpiece and the first gripping device has released the first Forging workpiece continues to grips, in a partially sectioned side view, and
• 10 a second embodiment analogous 2 , but with a different function of the gripping devices,

each shown schematically. Corresponding parts and sizes are in the 1 until 10 provided with the same reference numbers.

In the 1 until 10 a forging rolling machine 50 is shown at least in parts, which has at least one first roll 1 with a central axis of rotation A1 and at least one second roll 2 with a central axis of rotation A2.

In the top view of 1 the lower roller 2 is covered by the upper roller 1. According to 1 two bearing devices 41 and 42 for the rollers 1 and 2 as well as a rotary drive device 40 are provided, which can be designed in a manner known per se. However, according to the invention, the rotary drive device 40 is reversible in the direction of rotation in order to reverse the direction of rotation of the roller, as will be explained in more detail below.

The two rolls 1 and 2 are according to 2 until 10 along a vertical plane VE running in the direction of gravity, which extends with a horizontal, i.e. perpendicular to gravity, plane H1 of the upper roller 1 in the axis of rotation A1 and with a second horizontal plane H2 of the lower roller 2 in its axis of rotation A2 cuts. A third horizontal plane H3 is arranged between the planes H1 and H2 and the rolls 1 and 2 and forms a plane which passes through the nip 53 between the rolls 1 and 2 and along which the workpiece 3 is moved during rolling therefore also referred to here as workpiece level H3. The horizontal planes H1, H2 and H3 and the axes of rotation A1 and A2 are directed parallel to one another. The rollers are thus arranged horizontally and one above the other in the exemplary embodiments shown, with the first roller 1 being the upper roller and the second roller 2 being the lower roller.

However, the arrangement of the rollers can also be selected differently in space or with respect to gravity, for example rotated by 90° in such a way that the planes VE and H1 to H3 and the axes of rotation A1 and A2 are all vertical, i.e. parallel to gravity, the rollers are therefore vertical, or, alternatively, also in such a way that the plane VE and the axes of rotation A1 and A2 are horizontal and the planes H1 to H3 are vertical, ie the rollers are arranged next to one another and horizontally. Other e.g. oblique roller arrangements are also possible. The workpiece feed then changes accordingly.

In the 2 until 5 is the first direction of rotation D11 of the upper roller 1 counterclockwise and the first direction of rotation D21 of the lower roller 2 is directed clockwise, while in the 6 until 9 conversely, the second sense of rotation D12 of the upper roller 1 is clockwise and the second sense of rotation D22 of the lower roller 2 is counterclockwise, the rollers 1 and 2 thus being opposite to the state according to FIG 2 until 5 rotate. Due to the counter-rotation of the rollers 1 and 2 both in accordance with the operation 2 until 5 as well as in operation 6 until 9 run in the work provided for the workpiece 3 and its movement piece plane H3, the two rollers 1 and 2 on their outer sides in the same direction, ie their tangential web speeds are the same amount there and parallel to each other. As a result, the workpiece 3 is also in this tangential direction in a feed direction VR in 2 until 5 or in the opposite feed direction -VR in 6 until 9 moved by the rolls 1 and 2, as is generally provided for longitudinal rolling.

A first rolling tool with two ring-segment-like tools or tool segments 11 and 12 and a second rolling tool with two ring-segment-like tools or tool segments 11' and 12' are arranged on the circumference of the upper roll 1, the first and second rolling tools being in an axially offset arrangement and being the tool segment 11 around the axis of rotation A1 by an extension angle (or segment angle) γ1, the tool segment 11' by an extension angle γ1', the tool segment 12 by an extension angle γ2 and the tool segment 12' by an extension angle γ2'. Between the first tool segment 11 and the second tool segment 12 of the first rolling tool, an intermediate space 13 and diametrically opposite a further intermediate space 14 are arranged in each case at their circumferential ends. Likewise, in the case of the second rolling tool between the first tool segment 11' and the second tool segment 12' an intermediate space 13' is arranged at their circumferential ends and another intermediate space 14' is arranged diametrically opposite. A radial intermediate space plane ZE1 running centrally through the intermediate spaces 13 and 14 and 13' and 14' also runs through the axis of rotation A1 and the two tool segments 11 and 12 or 11' and 12' of the two rolling tools lie on opposite sides of this intermediate space plane ZE1 .

Similarly, in the case of the lower roller ZE2, two tool segments 21 and 22 or 21' and 22' are arranged on the circumference for each roller tool with the extension angles (segment angles) δ1 and δ2 or δ1' and δ2', which are separated by gaps 23 and 24 or 23 'and 24' are separated from each other and are on different sides by a radial central space plane ZE2 of the spaces 23 and 24 or 23' and 24'.

Tool segments 11 and 21 and 11' and 21' each work together as a first pair of rolling tool segments for rolling a workpiece, and tool segments 12 and 22 and 12' and 22' each work together as a second pair of rolling tool segments for rolling a workpiece. In principle, however, tool segment 12 could also be combined with tool segment 21 as a rolling tool segment pair and tool segment 11 with tool segment 22 (or correspondingly tool segment 12' with tool segment 21' and tool segment 11' with tool segment 22'), provided that the design the tool contours or profiles allow this.

The tool shape of the tool segments, in particular their profiles and contours, are adapted to the desired shape of the workpiece to be rolled. In the illustrated embodiment, according to a first rolling step 2 until 5 the cross section of the workpiece 3 tapers for better material distribution in a stretching step and in a second rolling step according to FIG 6 until 9 a partial further taper on the workpiece 3 introduced. However, a wide range of design options are possible and the specific shape and shaping by the tool segments 11 and 12 or 11' and 12' and 21 and 22 or 21' and 22' is in no way restricted according to the invention.

The extension angles γ1, γ1', γ2 and γ2' of the tool segments 11, 11', 12 and 12' are the same in the illustrated embodiment (γ1 = γ1' = γ2 = γ2') and the tool segments 11 and 12 or 11' and 12 'are also arranged essentially symmetrically to the intermediate space plane ZE1. The same applies to the tool segments 21, 21', 22 and 22' and their extension angle δ1=δ1'=δ2=δ2' and symmetrical arrangement with respect to the intermediate space plane ZE2. It also follows from this that all extension angles γ1, γ1′, γ2 and γ2′ as well as δ1, δ1′, δ2 and δ2′ are each smaller than 180°. However, this does not have to be the case, the extension angles γ1 and γ2, γ1' and γ2', δ1 and δ2 as well as δ1' and δ2' can also differ in pairs and it can even be one of the two extension angle pairs γ1 and γ2, γ1' and γ2' , δ1 and δ2 as well as δ1' and δ2' must be greater than 180°. In addition, the arrangement of the tool segments does not necessarily have to be symmetrical to a plane of symmetry.

The angles of rotation α11 to α24 and α11 'to α24' of the rollers 1 and 2 are in the 2 until 10 measured or defined between the intermediate space plane ZE1 or ZE2 and the horizontal plane H1 or H2 of the respective roll 1 or 2. Of course, each angle of rotation can also be related to other reference planes or axes. This is just a matter of definition.

There are also in 1 until 10 a gripping device 5 and a gripping device 6 are provided for gripping workpieces, which in particular form gripping tongs and/or which are attached to an associated handling device 15, 16, preferably one Robots, such as an industrial robot or a manipulator, are attached and are moved by this handling device 15, 16, in particular along the workpiece plane H3, which lies between the tool segments 11 and 21 and 12 and 22 in 2 until 5 or. 11' and 21' as well as 12' and 22' in 6 until 19 lies.

In the following, the process sequence when forging a metallic workpiece 3 by longitudinal rolling using the rollers 1 and 2 and their tool segments 11 and 21 is now based on the 2 until 5 described. Before rolling, the workpiece 3 is preheated to a forging temperature sufficient for forming or flowing its metallic material.

In 2 On a first working side 51 of the arrangement of rollers 1 and 2, here the working side on the left, a workpiece 3.1 designed as a blank, which is held or gripped by the gripping device 5, is moved along the workpiece plane H3 in the spaces between the gaps 23 and 13 Area introduced at the nip 53. The workpiece blank 3.1 is designed in particular as a short, cylindrical, solid or block-shaped, metallic, preheated forged part.

The angle of rotation α11 of the first roller 1 and α21 of the second roller 2 is in a range between 0 and 90°, in particular 20° and 70°, here in 2 about 50° to 60°. As a result, the gaps 13 and 23 open somewhat to the left towards the workpiece 3, so that this can easily be fed into the area between the gaps 13 and 23. This feeding of the workpiece 3 can take place when the rollers 1 and 2 are stationary or also when the rollers 1, 2 are rotating slowly or even at high to full speed. Only the feeding through the gripping device 5 then has to be carried out with the rotation of the rollers 1 and 2 synchronized or adjusted.

During the longitudinal rolling, the gripping device 5 moves along the workpiece plane H3 in the feed direction VR after or with it in order to follow the workpiece 3 being carried along by the rollers 1 and 2 . The feed direction VR is due to the selected directions of rotation D11 and D21 of the rollers 1 and 2 from the first working side 51 to the opposite second working side 52 of the roller arrangement in the 2 until 9 is arranged on the right, is directed, ie runs from left to right here, as indicated by the arrow.

According to 3 the two rollers 1 and 2 have rotated further, namely the first roller 1 to the new angle of rotation α12 and the second roller 2 to the angle of rotation α22, both of which are almost 90°. The first tool segment 11 of the first roller 1 and the first tool segment 21 of the second roller 2 now engage in the workpiece 3 as a pair of tool segments. Workpiece 3, which is now being formed, is in 3 referred to as workpiece 3.2 in the initial stage of the rolling process.

In 4 the rollers 1, 2 have been rotated further to an angle of rotation α13 or α23 which is greater than 180°, for example 190° to 200°. The workpiece 3.3 has now already been stretched or formed by a considerable length between the tool segments 11 and 21 and is therefore in an intermediate stage of the rolling process. In this stage of the rolling process, the workpiece 3.3 has also been transferred from the first gripping device 5 to the second gripping device 6, as is not explicitly shown. At about half the workpiece length, the second gripping device 6, which is arranged and working on the second working side 52, grips the workpiece 3 at its front end that has already passed through the rolling process, and at the same time or with a slight time delay, the first gripping device 5 releases the rear end of the workpiece 3 that has not yet been rolled. From this point on, the second gripping device 6 is responsible for holding, guiding and further handling of the workpiece 3 .

In 5 the rolling process is in the final stage and the workpiece 3 has been completely forged. The gripping device 6 is now the workpiece 3, which in 5 denoted by 3.4 in its final stage, and continues to hold it at its leading end in the completed rolling process. The two reels 1 and 2 are in 5 rotated further to an angle of rotation α14 or α24 of slightly less than 360°, with the pair of tool segments 12 and 22 facing each other at the tool gap 53 at this angle of rotation. In this stage, no rolling takes place, since the workpiece 3 has already been finish-forged with the pair of tool segments 11 and 21 and is held by the second gripping device 6 on the second working side 52 outside the forging area. The further rotating rollers 1, 2 are located in 5 kind of idle.

The forge-rolling of the workpiece 3 in the sequence according to FIG 2 until 5 is now complete and the workpiece 3 can be deposited by the gripping device 6 depending on the process requirements or, as in 6 until 9 shown, subjected to a further rolling step or forging step by a further pair of tool segments 11 ', 21' of the forging rolling machine 50.

The further forging step on workpiece 3 is now according to FIG 6 until 9 again between the same rollers 1 and 2 but with reversed direction of rotation and with the aid of the second pair of tool segments 11', 21'. In this case, the rolls 1 and 2 and their tool segments 11' and 12' or 21' and 22' are opposed to the rolling process according to FIG 2 until 5 rotates, which is caused by the opposite directions of rotation D12 (here clockwise) and D22 (here counterclockwise) in 6 until 9 compared to the senses of rotation D11 and D21 in the 2 until 5 is clarified. The workpiece 3 still has a sufficient forging temperature, ie it was heated before the entire forging process to a forging temperature which is sufficient for a two-stage forging. In order to be able to feed the workpiece 3 to the second pair of tool segments 11', 21', which is arranged axially offset on the rollers 1, 2 in relation to the first pair of tool segments 11, 21, the second gripping device 6 (as not explicitly shown) transports the workpiece 3 , preferably in a movement parallel to the roller axes of rotation A1, A2, from the removal area of the first pair of tool segments 11, 21 to the feeding area of the second pair of tool segments 11', 21'. Any other, non-parallel movement path is conceivable as long as it is expedient for the transport, but parallel transport is generally the most favorable in terms of time requirement.

As in 6 shown, the workpiece 3, in this initial stage of the second forging step because of its relative to the final stage after the first forging step according to 5 unchanged shape still referred to as workpiece 3.4, by means of the second gripping device 6, which is arranged on the second working side 52 of the rollers 1 and 2, from this second working side 52 to the tool segment pair 11', 21'. The workpiece 3.4 is fed in again by a feed movement along the workpiece plane H3 in the area between the gaps 23' and 13' at the roller gap 53, but because of the reverse direction of rotation of the rollers 1, 2 in an opposite feed direction -VR, which is the case with the is expressed by the minus sign compared to the feed direction VR in the first forging step of the workpiece 3.4.

The workpiece 3 is now in the 6 until 9 in various stages of the second forging process analogous to that in FIGS 2 until 5 shown forging process between the tool segments 11 'and 21' formed, depending on the stage shown in the 6 until 9 is denoted by 3.4 to 3.7.

The rotation angle α11' of the first roll 1 and α21' of the second roll 2 in the initial stage of the second forging step according to FIG 6 is again analogous to the initial state of the first forging step 2 each in a range between 0 and 90°, in particular 20° and 70°, here in 6 about 50° to 60°. When specifying the angles, however, it should be noted that all angles of rotation of the 6 until 9 compared to the angles specified in 2 until 5 because of the reverse direction of rotation of the rollers 1, 2 would have to carry a negative sign, but for the sake of simplicity all angles of rotation are given with their amount.

At this angle of rotation of about 50° to 60°, the gaps 13' and 23' open slightly to the right towards the workpiece 3, so that this can easily be fed into the area between the gaps 13' and 23'. In the second forging step, too, the workpiece 3 can be fed in while the rollers 1 and 2 are stationary or rotating at any speed, provided that appropriate synchronization with the feeding gripping device 6 has to be ensured.

During the second forging step, the gripping device 6 moves along the workpiece plane H3 in the feed direction -VR during the longitudinal rolling, in order to follow the entrainment of the workpiece 3 by the rolls 1 and 2.

According to 7 the two rollers 1 and 2 have rotated further, namely the first roller 1 to the new angle of rotation α12' and the second roller 2 to the angle of rotation α22', both of which are almost 90°. The first pair of tool segments 11', 21' of the second rolling tool now engage in the workpiece 3, which in accordance with this forming stage 7 is referred to as workpiece 3.5.

In 8th the rollers 1, 2 have been rotated further to an angle of rotation α13' or α23' which is greater than 180°, for example 190° to 200°. The workpiece 3.6 has now been further formed between the tool segments 11' and 21'. At this stage of the second rolling process, as in 8th shown, the transfer of the workpiece 3.6 from the second gripping device 6 back to the first gripping device 5. At about half the workpiece length, the first gripping device 5 arranged and working on the first working side 51 grips the workpiece 3 at its front end, which has already passed through the second forging step, and at the same time or with a slight time delay, the second gripping device 6 releases the end of the workpiece 3 that has not yet been rolled. From this point in time onwards, the first gripping device 5 is again responsible for holding, guiding and further handling of the workpiece 3 .

In 9 the second forging step is in the final stage and the workpiece 3 has been completely forged. The first gripping device 5 is now the workpiece 3, which in 9 denoted by 3.7 in its final stage, and continues to hold it at its leading end in the completed rolling process. The two reels 1 and 2 are in 9 rotated further to an angle of rotation α14' or α24' of somewhat less than 360°, with the pair of tool segments 12' and 22' facing each other at the tool gap 53 at this angle of rotation. The rolling is complete at this stage, the further rotating rollers 1, 2 are in 9 analogous to 5 kind of idle.

After the second forging step has been completed, another machining step can follow, or the workpiece 3 has been finished and can be transported away. In any case, however, the transport process is carried out by the first gripping device 5 .

The embodiment according to 2 until 9 is just one particular practical example of the embodiment of the present invention. Other different variants are conceivable and could also be shown. In particular, in the embodiment described above, the transfer of the workpiece 3 takes place during the forging step, such as when the workpiece 3 has already been forged halfway. The workpiece 3 can be transferred from one gripping device to the other, for example, only after the forging step has been completed. A handover of the workpiece 3 before the forging step is also possible and in some cases advantageous, since with special configurations of the workpiece 3 it can be better guided if the responsible gripping device 5, 6 runs in front of the workpiece 3 and pulls it behind it, so to speak. The latter variant is based on the 10 briefly indicated.

10 shows one opposite 2 Changed starting position at the beginning of the first forging step. while in 2 the first gripping device 5 feeds the workpiece 3 to the tool segment pair 11, 21 and also grips it during the first phase of the forging step, the first gripping device 5 takes over in the embodiment according to FIG 10 the workpiece 3 requires the workpiece 3 to be made available on the first working side 51. During the entire forging step, however, the second gripping device 6 arranged or working on the second working side 52 is responsible for holding and guiding the workpiece 3. For this purpose, the transfer step for the workpiece 3 from the first gripping device 5 to the second gripping device 6 takes place before the start of the forging step, ie before the tool segment pair 11, 21 begins machining. As in 10 shown, the second gripping device 6 grips the workpiece 3 at its front end in the feed direction VR and immediately after the gripping by the second gripping device 6 the first gripping device 5 (not shown) releases the workpiece 3 . In the meantime, the rollers 1, 2 have continued to rotate in such a way that the pair of tool segments 11, 21 begins to forge. The second gripping device 6 runs ahead of the workpiece 3 during the entire forging step at the speed which the rollers 1, 2 specify as feed.

The forging process itself is carried out in a manner analogous to that in 2 until 5 shown. After the end of the forging step, the second gripping device 6 can either transport away the forged workpiece 3 or analogously to a second forging step 6 until 9 supply, where “supply” means “provide” as for the previous first forging step. The first gripping device 5 is responsible for gripping and holding the workpiece 3 during the second forging step 10 takes over.

In 10 are the same reference numerals as in 2 used and these also have the same meaning. However, it should be noted that the second gripping device 6 must move completely into the tool gap 53 before the forging step in order to pick up the workpiece and requires appropriate space. For this purpose, the gap 13 between the first tool segment 11 and the second tool segment 12 on the roll 1 and the gap 23 between the first tool segment 12 and the second tool segment 22 on the roll 2 are compared to the embodiment according to FIG 2 greater. This also means that the angles of rotation α11 and α21 of the rolls 1, 2 are opposite at the beginning of the forging step 2 are also larger, in 10 about 100° to 110°.

Reference List

1

first roll

2

second roll

3

workpiece

3.1 to 3.4

Workpiece in different stages

5

first gripping device

6

second gripping device

9, 9'

conveyor

11

first tool segment of the first rolling tool on roll 1

11'

first tool segment of the second rolling tool on roll 1

12

second tool segment of the first rolling tool on roll 1

12'

second tool segment of the second rolling tool on roll 1

13, 14; 13', 14'

space

15

first handling device

16

second handling device

21

first tool segment of the first rolling tool on roll 2

21'

first tool segment of the second rolling tool on roll 2

22

second tool segment of the first rolling tool on roll 2

22'

second tool segment of the second rolling tool on roll 2

23, 24; 23', 24'

space

35

first gripper arm

36

second gripper arm

40

rotary drive device

41, 42

storage facilities

50

forge rolling machine

51

first working page

52

second work page

53

nip

A1

Axis of rotation of roller 1

A2

Axis of rotation of the roller 2

D11

first direction of rotation of roller 1

D12

second direction of rotation of roller 1

D21

first direction of rotation of the roller 2

D22

second direction of rotation of the roller 2

H1

Horizontal plane of the roller 1

H2

Horizontal plane of the roller 2

H3

workpiece level

PU

vertical plane

VR, -VR

feed direction

ZE1

Clearance level of roller 1

ZE2

Clearance level of roller 2

α11

first angle of rotation of the first roller 1

α12

second rotation angle of the first roller 1

α13

third angle of rotation of the first roller 1

α14

fourth angle of rotation of the first roller 1

α21

first angle of rotation of the second roller 2

α22

second angle of rotation of the second roller 2

α23

third angle of rotation of the second roller 2

α24

fourth angle of rotation of the second roller 2

γ1

Extension angle of the first tool segment 11

γ1'

Extension angle of the first tool segment 11'

γ2

Extension angle of the second tool segment 12

γ2'

Extension angle of the second tool segment 12'

δ1

Extension angle of the first tool segment 21

δ1'

Extension angle of the first tool segment 21'

δ2

Extension angle of the second tool segment 22

δ2'

Extension angle of the second tool segment 22'

Claims (13)

Process for forging, in particular stretch forging, of metal workpieces comprising the following process steps: a1) longitudinal rolling of a workpiece (3) in a forging step in each case with at least one pair of rolling tools, the two rolling tools of which are rotated in opposite directions of rotation (D11 and D21 or D12 and D22) about an associated axis of rotation (A1, A2), whereby the workpiece ( 3) formed between the rolling tools and moved in a feed direction (VR, -VR) resulting from the direction of rotation, b1) in a first feeding step, feeding a first workpiece (3) to a first pair of rolling tools (11 and 21 or 12 and 22) on a first working side (51) by means of a first gripping device (5), c1) Carrying out a forging step according to feature a1) with the first workpiece (3), the direction of rotation (D11, D21) of the two rolling tools (11 and 21 or 12 and 22) being set in such a way that the feed direction (VR) of the workpiece ( 3) is directed from the first working side (51) to a second working side (52) of the pair of rolling tools (11 and 21 or 12 and 22), which is arranged away from the first working side (51), and wherein the first gripping device (5 ) follows the feed movement of the first workpiece (3) in the feed direction (VR) during at least a portion of the forging step, d1) in a transfer step during or after the forging step, transferring the first workpiece (3) from the first gripping device (5), which is arranged or works on the first working side (51), to a second gripping device (6), which is on the second working side (51) is arranged or works and grips the first workpiece (3), the first gripping device (5) releasing the first workpiece (3) at the same time as it is being gripped by the second gripping device (6) or with a time delay. procedure after claim 1 , a2) in which at least one second pair of rolling tools (11' and 21' or 12' and 22') is provided, which is arranged next to the first pair of rolling tools (11 and 21 or 12 and 22) and/or the one with the first pair of rolling tools (11 and 21 or 12 and 22) has a common first working side (51) and a second working side (52) common to the first pair of rolling tools (11 and 21 or 12 and 22), b2) in which the second gripping device (6) in a second feeding step the first workpiece (3) after the first forging step in the first pair of rolling dies (11 and 21 or 12 and 22) and the first transfer step to the second pair of rolling dies (11' and 21' or 12' and 22') on the second working side ( 52), c2) in which a second forging step according to feature a1) is carried out with the first workpiece (3) in the second pair of rolling tools (11' and 21' or 12' and 22'), the direction of rotation (D11, D21) of the two rolling tools (11', 21') of the second pair of rolling tools (11' and 21' or 12' and 22') is set in such a way that the feed direction (-VR) of the workpiece (3) is from the second working side (52) to the first working side (51), and wherein the second gripping device (6) follows the feed movement of the first workpiece (3) in the feed direction (-VR) during at least a portion of the second forging step, d2) and in which in a second transfer step during or after the second forging step, the first workpiece (3) is transferred again from the second gripping device (6) to the first gripping device (5), the first gripping device (5) gripping the first workpiece (3) and the second gripping device (6) releases the first workpiece (3) at the same time as it is being gripped by the first gripping device (5) or with a time delay. procedure after claim 1 or 2 , a3) in which, in a further feeding step, preferably after the second transfer step for the first workpiece (3), at least one pair of rolling tools, preferably the first pair of rolling tools (11 and 21 or 12 and 22), a second workpiece is placed on the second working side (52 ), preferably by the second gripping device (6), and b3) a forging step according to feature a1) is carried out with the second workpiece, the direction of rotation (D12, D22) of the two rolling tools being set in such a way that the feed direction (-VR ) of the second workpiece from the second working side (52) is directed towards the first working side (51), and wherein the second gripping device (6) follows the feed movement of the second workpiece in the feed direction (-VR) during at least a portion of the forging step, c3) and in which in a transfer step during or after the forging step, the second workpiece is transferred from the second gripping device (6) to the first gripping device (5), the first gripping device (5) gripping the second workpiece and the second gripping device (6) gripping the second workpiece at the same time as it is gripped releases the first gripping device (5) or with a time delay. Process for forging, in particular stretch forging, of metal workpieces comprising the following process steps: a4) longitudinal rolling of a workpiece in a forging step in each case with at least one pair of rolling tools, the two rolling tools of which are rotated in opposite directions (D11 and D21 or D12 and D22) about an associated axis of rotation (A1, A2), as a result of which the workpiece is formed between the rolling tools and is moved in a feed direction (VR, -VR) resulting from the direction of rotation, b4) in a first feeding step, feeding a first workpiece (3) to a first pair of rolling tools (11 and 21 or 12 and 22) on a first working side (51) by means of a second gripping device (6), c4) carrying out a forging step according to feature a4) with the first workpiece (3), the direction of rotation (D11, D21) of the two rolling tools (11 and 21 or 12 and 22) being set in such a way that the feed direction (VR) of the workpiece ( 3) is directed from the first working side (51) to a second working side (52) of the pair of rolling tools (11 and 21 or 12 and 22), which is arranged away from the first working side (51), and wherein the second gripping device (6 ) follows the feed movement of the first workpiece (3) in the feed direction (VR) during at least a portion of the forging step, d4) in a transfer step before the forging step, transferring the first workpiece (3) from a first gripping device (5) arranged or working on the first working side (51) to the second gripping device (6) working on the second working side ( 52) is arranged or is working and grips the first workpiece (3), the first gripping device (5) releasing the first workpiece (3) at the same time as it is being gripped by the second gripping device (6) or with a time delay. procedure after claim 4 , a5) in which at least one second pair of rolling tools (11' and 21' or 12' and 22') is provided, which is arranged next to the first pair of rolling tools (11 and 21 or 12 and 22) and/or the one with the first pair of rolling tools (11 and 21 or 12 and 22) has a common first working side (51) and a second working side (52) common to the first pair of rolling tools (11 and 21 or 12 and 22), b5) in which the first gripping device (6) in one second feeding step feeding the first workpiece (3) after the first forging step in the first pair of rolling tools (11 and 21 or 12 and 22) to the second pair of rolling tools (11' and 21' or 12' and 22') on the second working side (52), c5) in which a second forging step according to feature a4) is carried out with the first workpiece (3) in the second pair of rolling tools (11' and 21' or 12' and 22'), the direction of rotation (D11, D21) of the two rolling tools ( 11', 21') of the second pair of rolling tools (11' and 21' or 12' and 22') is set in such a way that the feed direction (-VR) of the workpiece (3) is from the second working side (52) to the first working side (51 ) is directed, and wherein the first gripping device (5) follows the feed movement of the first workpiece (3) in the feed direction (-VR) during at least a portion of the second forging step, d5) and wherein in a second transfer step before the second forging step the first workpiece (3) is transferred back to the first gripping device (5) by the second gripping device (6), the first gripping device (5) gripping the first workpiece (3) and the second gripping device (6) gripping the first workpiece (3) releases at the same time as being gripped by the first gripping device (5) or with a time delay. procedure after claim 4 or 5 , a6) in which, in a further feeding step, preferably after the second transfer step for the first workpiece (3), at least one pair of rolling tools, preferably the first pair of rolling tools (11 and 21 or 12 and 22), a second workpiece is placed on the second working side (52 ), preferably by the first gripping device (5), and b6) a forging step according to feature a4) is carried out with the second workpiece, with the direction of rotation (D12, D22) of the two rolling tools being set in such a way that the feed direction (-VR ) of the second workpiece is directed from the second working side (52) to the first working side (51), and wherein the first gripping device (5) follows the feed movement of the second workpiece in the feed direction (-VR) during at least a portion of the forging step, c6) and wherein in a transferring step before the forging step, the second workpiece is transferred from the second gripping device (6) to the first gripping device (5), the first gripping device (5) gripping the second workpiece and the second gripping device (6) releases the second workpiece at the same time as it is being gripped by the first gripping device (5) or with a time delay. Method according to one of the preceding claims, in which in a first removal step the first workpiece (3) is removed on the first or second working side (51 or 52) and/or in a second removal step the second workpiece is removed on the first or second working side (51 or 52) is discharged. Method according to one of the preceding claims, in which the rolling tools are not moved apart between the reversal of their direction of rotation, but the workpiece (3) is moved completely out of the gap (13, 13', 14, 14') in the respective feed direction (VR, -VR) , 23, 23', 24, 24') or nip (53) between the rollers (1, 2) or in the gap (13, 13', 14, 14', 23, 23', 24, 24') or Roller gap (53) to the other gripping device (5 or 6) and then transported or handled by the respective gripping device (5 or 6). Method according to one of the preceding claims, in which the sequence of method steps is carried out several times in succession with different successive workpieces. Method according to one of the preceding claims, in which the workpieces are fed in and/or removed along a workpiece plane (H3) which passes through a roller gap (53) or intermediate space (13, 13', 14, 14', 23, 23', 24, 24') between the rolls (1, 2) and/or which runs perpendicular to a plane (VE) running through the two roll axes (A1, A2) and/or which runs essentially tangentially to the roll shell surfaces. Comprising forging-rolling apparatus for carrying out a method according to any one of the preceding claims - at least one pair of rollers (1 and 2) with two rollers (1, 2) each rotatable about a roller axis (A1, A2) and reversible in the direction of rotation (D12, D22), - a first gripping device (5) arranged or operating on the first working side (51) of the rollers (1, 2) for gripping and moving and/or for removing and/or for providing a first workpiece (3) and one on the second working side (52) of the rollers (1, 2) arranged or operating second gripping device (6) for gripping and moving and/or for removing and/or for preparing a second workpiece. Forge rolling device according to claim 11 , each of the two rollers (1, 2) of the pair of rollers (1 and 2) being fitted with two tool segments (11, 11', 12, 12'), with each tool segment (11, 11', 12, 12') preferably extends by a respective segment angle of less than 180° around the associated roll axis (A1, A2) and/or the two tool segments (11, 11', 12, 12') in relation to a central plane (ZE1 , ZE2) of the roller (1, 2) are arranged on different halves of the roller (1, 2). Forge rolling device according to claim 11 or 12 , in which one rolling tool (11, 12) of the first pair of rolling tools (11 and 21 or 12 and 22) is provided on a first roll (1) and the other rolling tool (21, 22) on a second roll (2) and/or in which one rolling tool (11', 12') of the second pair of rolling tools (11' and 21' or 12' and 22') on the first roll (1) and the other rolling tool (21', 22') of the second pair of rolling tools (11 ' and 21' or 12' and 22') are provided on the second roller (2).

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