EP1454684A2 - Method for forming a workpiece and rolling machine - Google Patents

Abstract

A rolling mill with a new process control has work pieces forged between two profiled rollers. The speed and position is controlled on at least one roller with the rolling speed controlled w.r.t. the position of the work piece. The process cycle comprises a positioning phase at a slow speed, a rolling phase at a higher speed and a final phase in which the work piece is returned at a slower speed.

Description

The invention relates to a method for forming a workpiece and a rolling machine that is suitable for performing the method.

For forming workpieces from an initial shape into a desired one Intermediate form (semi-finished, preforming) or final form (finished product, Finished molds) are, among many other processes, also rolling processes known, which are counted among the pressure forming processes. When rolling the workpiece (rolling stock) is placed between two rotating rollers and by applying a forming pressure through the rotating rollers changed in shape. Tool profiles are used in the profile rolling process arranged on the circumference of the rollers, which corresponding to the generation Enable profiles in the workpiece. When rolling flat, the cylindrical ones work or conical outer surfaces of the rollers directly on the workpiece.

With regard to the relative movement of the tools or rollers on the one hand and on the other hand, the workpiece is divided into longitudinal rolls, Cross rolls and cross rolls. The workpiece becomes vertical during longitudinal rolling to the axes of rotation of the rollers in a translatory movement and mostly without rotation through the space between the rollers (roller gap) emotional. The workpiece does not move translationally during cross rolling regarding the rollers or their axes of rotation, but only rotates about its own axis, which is usually a major axis of inertia, in particular the axis of symmetry for a rotationally symmetrical workpiece, is. When combining both types of movement in longitudinal rolling and in Cross rolling is referred to as cross rolling. The rollers are in the Usually at an angle to each other and to the workpiece, which is translational and rotational is moved.

Profile cross rolling machines in which two rolls are arranged on the outer circumference wedge-shaped profile tools around mutually parallel axes of rotation Rotating in the same direction is sometimes referred to as cross wedge rolling. The tools have a wedge-shaped or triangular cross-section Geometry and can be radial along its circumference Increase dimension in one direction and / or at an angle to the axis of rotation of the Rolls run.

These cross wedge rollers or profile cross rollers allow a variety of forming of workpieces with high precision or dimensional accuracy. As a result the pressure force exerted on the workpiece by the wedge-shaped tools the material distribution in the workpiece during the circulation the rollers are changed by a flow process in the workpiece. The wedge-shaped Tools can have circumferential grooves and other tapering in the rotating workpiece. Due to the axial offset in the circumferential direction or the oblique arrangement of the tool wedges relative to The axis of rotation can, for example, change structures axially to the axis of rotation and tapering in the workpiece. By the increase or decrease in the outside diameter of the tool wedges during the course the axis of rotation can be axial in combination with the oblique arrangement running slopes and continuous transitions between two tapers different diameters can be generated in the workpiece. The Wedge shape of the tools allows the production of fine structures through the Wedge outer edges or outer surfaces. Cross wedge rollers are particularly suitable for the production of elongated, rotationally symmetrical workpieces with constrictions or elevations such as cams or ribs.

The forming pressure force and the forming temperature depend on that Material from which the workpiece is made and the requirements the dimensional accuracy and surface quality after forming. In particular in the case of iron or steel materials, the forming is usually carried out carried out during rolling at elevated temperatures in order to form required formability or flowability of the material to reach. These temperatures, particularly those that occur during forging With a so-called cold forming in the range of room temperature, for semi-hot forming between 550 ° C and 750 ° C and at a so-called hot forming are above 900 ° C. The forming or Forging temperature is usually also in a temperature range placed in the recovery and recrystallization processes in the material run and undesirable phase changes are avoided.

Cross wedge rolling machines (or: profile cross rolling machines) are known in which the workpieces at the beginning of the rolling process by means of a positioning device, which includes two positioning supports (so-called guidelines), in a starting position between the two rollers, which is usually the corresponds to the geometric center or the center of the nip. Now the positioning brackets of the positioning device are withdrawn, so that the workpiece rotates freely between the rollers and between the tools are kneaded into the desired shape. After this Rolling or kneading process and the corresponding completion of the workpiece the workpiece is cut out in the rotating rolling tool captured and ejected.

From DE 1 477 088 C a cross wedge rolling machine is known for the transverse rolling of rotary bodies or flat workpieces with two work rolls rotating in the same direction of rotation, on the roll surfaces of which wedge tools are interchangeably arranged. The wedge tools each have wedge-shaped or triangular-shaped, increasing from the roller jacket to a height end position adapted to the workpiece to be manufactured, roughened by knurling or other means, and wedge-shaped smooth shaped surfaces with the same distance from the roller jacket with calibration effect. The wedge tools are designed as deformation segments and only run over a partial circumference of the associated roller surface. The surfaces and tools of the two work rolls facing each other move in opposite or opposite directions on the workpiece.

EP 1 256 399 A1 discloses a cross-rolling machine with two modules operated in parallel, each with two rollers rotating in the same direction of rotation, which have half-shell-shaped tools with radially projecting tool wedges on their circumferential surface, the reshaping of a workpiece only rotating around half the circumference of a pair of rollers requires. All four rollers are driven by only one drive motor via an intermediate gear unit and drive shaft.

DE 195 26 071 A1 discloses a device for rolling profiles into a workpiece, in particular cross rolls, longitudinal rolls and cross rolls of threads, knurls, toothed roll profiles or the like, with two forming rolls which are rotated about mutually parallel axes of rotation in the same direction of rotation and each are driven by an associated drive with a drive motor, each drive being assigned a braking device.

DE 21 31 300 B discloses a cross rolling machine with two axially parallel, horizontally superimposed profile rollers for shaping and cutting rotationally symmetrical workpieces, in which the profile rollers touch the workpieces diametrically opposite circumferential points and the lower profile roller has a recess for removing the rolled and cut workpieces from the roll gap having.

The invention is based on the object, a new method for Forming workpieces and a new rolling machine with which this Procedure is feasible to specify.

This object is achieved with regard to the method according to the invention with the features of claim 1.

a) Anordnen des Werkstücks zwischen wenigstens zwei rotierenden, mit Werkzeugen versehenen (bestückten) Walzen und

b) Einstellen (Steuern oder Regeln) der Rotationsgeschwindigkeit, insbesondere der Winkelgeschwindigkeit, Drehzahl oder Umfangsgeschwindigkeit, wenigstens einer der Walzen in Abhängigkeit von der Drehposition wenigstens einer der Walzen.

The process for forming a workpiece comprises the following process steps:

a) arranging the workpiece between at least two rotating, tooled (equipped) rollers and

b) adjusting (controlling or regulating) the rotational speed, in particular the angular speed, rotational speed or peripheral speed, of at least one of the rollers as a function of the rotational position of at least one of the rollers.

The term "reshaping" means any transformation of the form of a Understood the workpiece in a different form, as described at the beginning, including preforms and preforms.

The object is achieved with regard to the rolling machine according to the invention with the features of claim 14.

The rolling machine according to claim 14 is for performing a method Suitable and also determined according to one of the preceding claims and comprises at least one permanent magnet motor, in particular one Torque motor for driving the rollers.

Advantageous design and development of the method and Rolling machine result from that of claim 1 and claim 14, respectively dependent claims.

In a first embodiment, the dependence of the rotational speed becomes or is of the rollers depends on the rotational position of the roller (s) selected from the machined workpiece. To do this, one is adapted to the workpiece optimal course of the rotational speed is determined in advance and then set when the workpiece is formed.

The method generally comprises at least three method steps or process phases. In a first process phase, the workpiece is between positioned the rollers. In a second process phase, this will be Workpiece formed between the rotating tools of the rollers. In In a third process phase, the workpiece is removed from the gap removed or ejected between the rollers. Over time Of course, these three process phases also change continuously Angle of rotation or the angular position of the rollers.

The rotational speed can now be used in different process phases and / or can also be varied within a process phase.

In a variant of the method, the rotation speed of the rollers chosen in the first process phase at least on average less than during the second process phase.

In an alternative or additional variant, the rotation speed of the rollers during the second process phase, at least on average chosen larger than during the third process phase. Preferably that is Workpiece during the first process phase using a positioning device automatically positioned between the rollers.

At the beginning of the second process phase, the workpiece is preferably from a recess in the tools of at least one roller and then during the second process phase between the tools of the two Rolled rolls. The speed of rotation will now be advantageous Embodiment after gripping the workpiece through the recess in the tools of the roller (s) increased.

The workpiece preferably continues at the beginning of the third process phase captured by a recess in the tools of at least one roller and ejected from the space between the rollers. Before the Detecting the workpiece through the further recess in the or Roller (s) the rotation speed of the rollers is now preferred reduced.

The rotational speeds when the workpiece is gripped at the beginning the second process phase and at the end of the second process phase are special about the same.

In a preferred embodiment, the rotation speed kept at least partially constant during the second process phase.

The rotation speed of the roller (s) can also in the second Process phase can be changed, especially if multiple tools are on the roller one after the other in different sub-process phases of the second Process the workpiece. For example, the speed of rotation be reduced at the beginning of a sub-process phase.

The speed of rotation can also be during the first process phase and the positioning of the workpiece kept at least partially constant become.

The rotation speed and / or direction of rotation of the rollers are or is at least in angular or time segments, preferably predominantly, set essentially equal to each other, but can also be set differently from one another at least in sections.

The current rotational position of the roller (s) can be from the starting position or Reference position of the roller (s) and the course of the rotational speed can be determined by calculation. However, the rotational position is preferred the roller (s) is determined by means of at least one position detection device. The position detection device preferably comprises at least an angular position incremental encoder or an absolute encoder and / or an optical, magnetic, inductive or ultrasonic angular position transmitter.

In a particularly advantageous embodiment, the rolling machine is one Profile cross rolling machine or cross wedge rolling machine. Because of the speed controllable and reversible drive is the rolling machine or cross wedge rolling machine can also be used as a stretch rolling machine or short stretch roll.

The permanent magnet motor preferably accelerates to the nominal speed to operate the rollers within a maximum rotation angle of 3 °, 2.2 °, 1 ° or 0.5 °. Furthermore, the permanent magnet motor preferably has a nominal torque between about 5,000 Nm and about 80,000 Nm, in particular between about 35,000 Nm and about 60,000 Nm, on and / or one Nominal speed between about 20 rpm and 800 rpm, in particular about 30 rpm or 500 rpm.

In a development of the rolling machine, the drive includes in addition to the at least one permanent magnet motor at least one transmission for transmission the torque or the rotational movement of the permanent magnet motor on the at least two rollers. The transmission includes in particular at least one coupled to the output shaft of the permanent magnet motor central drive gear and two with the drive gear in Engaging or bringable and coupled to one of the rollers Rolling gears. The gear ratio of the drive motor on each of the rollers is then generally the same and preferred in a range between 1: 1 and 1: 1.5. Such a The drive is in particular mechanically synchronized via the transmission

In addition to drives with PM motors, hydraulic drives also come as roller drives Drives and / or electric drives with other motors, in particular with synchronous or asynchronous motors and / or induction motors, in question. Independent drives for the rollers are used the rollers are electronically synchronized or controlled, especially via Inverters that, for example, have a mains voltage of 400 V and 50 Hz an alternating voltage or alternating current of suitable amplitude and Convert frequency. It is particularly advantageous here that with cross wedge rollers the load on both motors due to the symmetrical structure of the Tools / rollers and / or the symmetrical forming process comparatively is low and thus favors the synchronization of the drives is.

The rolling machine preferably further comprises one for each of the rolls associated drive, the drives being independent of each other. It can also be a common drive with at least one gear for both rollers can be provided.

FIG 1

eine Walzmaschine mit zwei Walzen und einem gemeinsamen Antrieb in einer teilweise geschnittenen Längsansicht,

FIG 2

die Walzmaschine gemäß FIG 1 in einer teilweise geschnittenen Draufsicht von oben,

FIG 3

die Walzmaschine gemäß FIG 1 und FIG 2 in einer Seitenansicht,

FIG 4

die beiden Arbeitswalzen einer Walzmaschine im Querschnitt vor Einbringen des Werkstückes,

FIG 5

die beiden Arbeitswalzen der Walzmaschine beim Einbringen des Werkstückes,

FIG 6

die Arbeitswalzen mit dem bearbeiteten Werkstück im Querschnitt,

FIG 7

die beiden Arbeitswalzen beim Auswerfen des Werkstückes und

FIG 8

eine mögliche Abhängigkeit der Winkelgeschwindigkeit einer Arbeitswalze vom Drehwinkel in einem Diagramm

FIG 9

eine weitere mögliche Abhängigkeit der Winkelgeschwindigkeit einer Arbeitswalze vom Drehwinkel in einem Diagramm

FIG 10

eine Ausführungsform einer Walzmaschine mit zwei Walzen und unabhängigen Antrieben für die Walzen in einer teilweise geschnitten Längsansicht und

FIG 11

die Walzmaschine gemäß FIG 10 in einer Seitenansicht.

jeweils schematisch dargestellt sind. Einander entsprechende Teile und Größen sind in den FIG 1 bis 11 mit denselben Bezugszeichen versehen.The invention is explained in more detail below on the basis of exemplary embodiments. Reference is made to the drawings in which

FIG. 1

a rolling machine with two rollers and a common drive in a partially sectioned longitudinal view,

FIG 2

1 in a partially sectioned top view from above,

FIG 3

the rolling machine according to FIG 1 and FIG 2 in a side view,

FIG 4

the two work rolls of a rolling machine in cross section before inserting the workpiece,

FIG 5

the two working rolls of the rolling machine when inserting the workpiece,

FIG 6

the work rolls with the machined workpiece in cross section,

FIG 7

the two work rolls when ejecting the workpiece and

FIG 8

a possible dependence of the angular speed of a work roll on the angle of rotation in a diagram

FIG. 9

another possible dependency of the angular speed of a work roll on the angle of rotation in a diagram

FIG 10

an embodiment of a rolling machine with two rollers and independent drives for the rollers in a partially sectioned longitudinal view and

FIG 11

the rolling machine of FIG 10 in a side view.

are each shown schematically. Corresponding parts and sizes are given the same reference numerals in FIGS. 1 to 11.

The embodiment shown in Figures 1 to 3 as a cross wedge roller or cross wedge rolling machine 1 comprises a first Work roll 2, which is rotatable or rotating about an axis of rotation A. and a second work roll 3 which is rotatable or about an axis of rotation B. is rotating. The direction of rotation of both work rolls 2 and 3 is with those shown Arrows illustrated and the same. The rotation axes A and B are arranged essentially parallel to one another, in the example in FIG. 1 to 3 seen one above the other in the direction of gravity, so that the Work rolls 2 and 3 are arranged one above the other. The work rolls have a substantially cylindrical outer surface. The distance between the cylindrical outer surfaces of the two work rolls 2 and 3 is marked with W.

On the outer surface or outer surface of the work rolls 2 and 3 are each cross-sectionally wedge-shaped tools 20 and 21 or 30 and 31 fastened, especially tense. In the illustrated embodiment the tools 20 and 21 of the first work roll 2 and the tools 30 and 31 of the second work roll 3 each at an angle and at an angle the respective axis of rotation A and B arranged, the tools 20 and 21 of the work roll 2 with respect to that between the two rolls parallel to the axis of rotation running, defining the geometric center M axially arranged in substantially the same positions are. The tools 20 and 21 and 30 and 31 take in the circumferential direction seen in their cross section, with the increase in cross section for tools 20 and 21 in the same direction of rotation or orientation and the tools 30 and 31 of the second work roll 3 opposite or opposite to that of the tools 20 and 21 of the first work roll 2.

Each work roll 2 and 3 is in a holding device consisting of two parts releasably held and can be unlocked from the holding device in its Condition can be taken out to replace the tools 20 and 21 or 30 and 31 or the entire work rolls 2 and 3 with the Tools 20 and 21 or 30 and 31. The holding device for the work roll 2 is designated 12 and the holding device for the work roll 3 with 13. A first part 12A of the holding device arranged on the left in FIGS. 1 and 2 12 includes a conical receptacle 14 for receiving a extending axially to the axis of rotation A outward from the work roll 2 truncated cone-shaped extension 24 (stub shaft). The second part 12B accordingly comprises a receptacle 15 for receiving a corresponding one tapered away from the work roll 2 and axially to Rotation axis A extending extension 25 of the work roll 2. Under the resulting Wedge and clamping effect, the work roll 2 is fixed in the recordings 14 and 15 of the holding device 12 clamped, the axial force towards the receptacle 15 in the direction of the axis of rotation A towards the work roll 2 for holding the work roll 2 by a spring 16 or another an axial force exerting element is generated. The recordings 14 and 15 are rotationally symmetrical to the axis of rotation A and are not shown in FIG designated pivot bearings.

The receptacle 14 continues as a hollow shaft axially to the axis of rotation A and has a gear in its end region facing away from the work roll 2 18 on, as well as a corresponding gear 19, that of the second work roll 3 is assigned, with a control gear (pinion, drive gear) 5 is engaged. The gear 18 that drives the first work roll 2 serves via the holding device 12, engages from above in the Control gear 5 and gear 19 connected to the second work roll 3 Coupled via the holding device 13, engages in the control gear from below 5th

The control gear 5 is now via an output shaft 45 with a drive motor 4 coupled. The control gear 5, the output shaft 45 and the - Not shown - the rotor of the drive motor 4 are a common Rotation axis R rotatable or rotating. The one from the drive motor 4, the output shaft 45 and the control gear 5 built drive for the Gears (roller gears) 18 and 19 and thus the synchronous with the Gear wheels 18 and 19 rotating work rolls 2 and 3 is thus a direct drive.

The mechanical power provided by the drive motor 4 corresponds to that Product of torque and angular velocity or angular frequency ω, where the angular frequency ω is equal to the product of 2π and the speed n is. The drive motor 4 is preferably a torque motor and has one high torque even with a comparatively low speed n of the drive motor 4 to generate the required drive power for the Drive rollers 2 and 3.

The transmission ratio from the control gear 5 to the gears 18 and 19 can thus be selected in the range around 1, in particular between about 1: 1 and about 1: 2. Turn at a transmission ratio of 2 the drive rollers 2 and 3 are twice as fast as the control gear 5 and the drive motor 4, with a transmission ratio of 1: 1 exactly so quickly. Typical speeds of work rolls 2 and 3 are between about 10 revolutions per minute (rpm) and about 40 rpm, typically at 15 rpm.

With such a low-speed or low-speed drive motor 4 can now be a very dynamic adjustment or control or regulation of the speed of the work rolls 2 and 3 can be realized.

A preferred embodiment of the drive motor 4 is a permanent magnet motor, where, usually on the rotor, permanent magnets (Permanent magnets) are arranged, one in the electromagnet or windings generated induction field of the stator rotating magnetic Generate flux, by interaction of the magnetic flux the permanent magnets and the induction field the rotation of the rotor on the basis of the induction principle or electromotive principle arises. In general, a torque motor is a synchronous motor, that is the rotor rotates synchronously with the rotating magnetic flux. The Induction windings of the stator are usually with the phases of one Three-phase connection connected and arranged offset by 120 ° to each other. Permanent magnets with the highest possible Energy product used, for example rare earth cobalt magnets. The For this purpose, the stator generally has an iron core with the three-phase winding package while the rotor has a cylindrical iron core with the Has permanent magnets. Such a torque motor can produce torque of up to 80,000 Nm. The high torque also works a very fast spin. In particular, the permanent magnet motor or torque motor the rollers within an angle of rotation from only 1 °, preferably even only 0.5 °, to the nominal speed, for example Accelerate 30 rpm. This high dynamic or spin of the torque motor allows a very dynamic control of the speed.

The control or regulation of the speed n of each other and synchronously rotating work rolls 2 and 3 is now according to the invention with a special control procedures or control procedures adapted to the rolling process. For this purpose the speed n or angular speed ω of the work rolls 2 and 3 to the respective rotary position or angular position ϕ of the work rolls 2 and 3 adapted and depending on this rotational position ϕ controlled. Depending on the respective process, the respective Rolling machine and especially depending on the workpiece to be machined Forming by the work rolls 2 and 3 by controlling the speed n or the angular velocity ω = dϕ / dt can be optimized.

4 to 7 now show a possible sequence of a rolling process such a rotational position-dependent speed control or regulation a workpiece 10. A positioning device for the workpiece 10 is designated 60 and comprises two relatively movable positioning parts (Guidelines) 61 and 62.

4 shows a position of the work rolls 2 and 3 before the introduction of the Workpiece. The same directions of rotation of the two rollers 2 and 3 around the respective axes of rotation A and B are marked with corresponding arrows. In the tool 20, which is segment-like around the outer surface of the work roll 2 and around the axis of rotation A is a recess 23 intended. In the second work roll 3 is also segment-like Tool 30 provided a further recess 33.

The workpiece 10 is now one not shown by means of two rulers Positioning device in a position between the work rolls 2 and 3 taught in which it from the recess 23 in the tool 20th the first work roll 2 is detected. This process phase with introduced 5 shows tool 10 in the starting position. On workpiece 10 the facing surfaces of the work rolls 2 move and 3 in opposite or opposite directions.

With the further rotation of the work rolls 2 and 3 to each other is now the workpiece 10 placed between the tools 20 and 30 and under the pressure of the tools 20 and 30, which are closer together w have than the original diameter of the workpiece 10 in spent a smaller diameter. The one created after the forming reduced diameter (puncture) of the workpiece 10 on the in Cross-section shown largely corresponds to the minimum distance w between the tools 20 and 30 of the work rolls 2 and 3. A Position of the work rolls 2 and 3 with the kneaded in between Workpiece 10 during the actual rolling process is shown in FIG. 6.

7 shows the position of the work rolls 2 and 3, in which the workpiece 10 in the recess 33 of the tool 30 falls in second work roll 3 and, with further rotation of the work roll 3, ejected from the space between work rolls 2 and 3 becomes.

You can basically distinguish three process phases in the rolling process, namely a first process phase to prepare the rolling process and positioning of the workpiece in the starting position, that is a process phase, which is shown in FIGS. 4 and 5, and a second Process phase during which the actual rolling process takes place and that Workpiece is formed between the tools of the two work rolls, 6, and finally a third process phase during which the workpiece is removed from the tools accordingly FIG 7.

8 shows a diagram in which the speed n of the work rolls 2 and 3 as a direct measure of the speed of rotation in the unit of measure Hertz (Hz) = 1 / s or specified in revolutions per second (or also: Revolutions per minute) above the rotational position or the rotational angle ϕ the work roll 2 is applied. There are nine consecutive angular positions ϕ1 to ϕ9 are drawn on the ϕ axis and between the Angular positions ϕ1 and ϕ9 the speed n as a function n (ϕ) of the angle of rotation ϕ applied. The curve resulting from this is denoted by K. This curve K is in turn divided into seven sub-curves K1 to K7, the first sub-curve K1 between the angular positions ϕ1 and ϕ2, the second sub-curve K2 between the angular positions ϕ2 and ϕ3, the third Sub-curve K3 between the angular positions ϕ3 and ϕ4, the fourth sub-curve K4 between the angular positions ϕ4 and ϕ5, the fifth sub-curve K5 between the angular positions ϕ5 and ϕ6, the sixth sub-curve K6 between the angular positions ϕ6 and ϕ7 and the seventh sub-curve K7 between the angular positions ϕ7 and ϕ8. The first sub-curve K1 and the second sub-curve K2 show a possible time course of the speed n of the work rolls 2 and 3 in the between the angular positions ϕ1 and ϕ3 lying first process phase for the preparation and positioning of the Workpiece 10. Between the angular positions ϕ1 and ϕ2 is in one quite steep rise according to the sub-curve K1 the speed from 0 to one first speed n1> 0 increased and then between the angular positions ϕ2 and ϕ3 kept essentially constant, according to the sub-curve K2.

In the period between ϕ2 and ϕ3, according to the sub-curve K2, the workpiece 10 positioned between the work rolls 2 and 3 and finally about the angular position ϕ3 from the recess 23 of the tool 20 of the first work roll 2 detected.

The angular position ϕ3 is now the angular position of the first rotating roller 2, in which the workpiece 10 is fixed in the recess 23 and the rolling process can start. It should be noted that the angular position or Rotary position of the second work roll 3 directly with the angular position of the Work roll 2 is correlated and synchronous, but in opposite directions with the Angular position of the first work roll changes, the rotation of the work rolls 2 and 3 in the same direction to each other. That is why it is sufficient that To consider the rotational position of the first work roll 2. It could, of course just like the angular position of the second work roll 3 as a variable or Parameters are taken on which the speed n is made dependent becomes. In any case, it is sufficient to use one of the two work rolls 2 or 3 Position detection device to be provided for determining the angle of rotation ϕ relative to a reference or zero position ϕ0, which in FIGS. 4 to 7 is chosen and drawn down.

When the angular position ϕ3 is reached and the workpiece 10 engages In the recess 23 the speed n is now between the angular position ϕ3 and a subsequent angular position ϕ4 quickly increased in the curve section K3 with a correspondingly high rotational acceleration or gradient of the characteristic curve K. The angular position ϕ4 is then a higher speed n2 reached at which the speed n during the sub-curve K4 up to one new angular position ϕ6 is held. This sub-curve K4 between the Angular positions ϕ4 and ϕ6 mark the actual rolling process. The FIG 6 shows a snapshot of this rolled section to the angular position ϕ5 of the work roll 2.

Shortly before the recess 33 of the tool 30 of the second work roll 3 reaches the workpiece 10, becomes one in front of the associated angular position ϕ7 of the first work roll 2 lying angle ϕ6 of the first work roll 2 the speed n is reduced again during the sub-curve K5, preferably again with a high braking acceleration and then with a lower braking acceleration, corresponding to a flatter slope in the sub-curve K6 between the angular positions ϕ7 and ϕ8 further decreased. So it will be ejecting the workpiece at a lower one RPM n and a lower spin performed to the Eject the workpiece gently. The workpiece is ejected on End of the sub-curve K6 at the angular position ϕ8 of the first work roll 2 ends and the speed n is now at the end of the machining process this workpiece 10 between the angles of rotation ϕ8 and ϕ9 accordingly the sub-curve K7 is reduced to speed n = 0 Hz. A work cycle or a forming process is thus ended.

Of course, other angle-dependent profiles of the Speed n are driven. So it is also possible to use the two work rolls 2 and 3 during sub-phases of the process with different from each other Rotate speeds or even different direction of rotation. Further can depend on the number and arrangement of tools on the work rolls the profile n (ϕ) can be controlled.

9 shows a dependency n (ϕ) at which during the forming process a more complicated profile is driven. First, starting from the Angular position ϕ0 and a speed n = n2 braked to one speed n1 with an angular position ϕ1. This speed n1 is up to an angular position Maintain beibehalten2 and then switch back to speed n2 at Angular position ϕ3 accelerates and this speed n2 up to the angular position ϕ4 maintained. This reduction in speed n is when threading or gripping the workpiece 10 is advantageous. For a first forming phase with a first tool, the angle positions ϕ4 and ϕ5 accelerates from a speed n2 to a higher speed n8 and maintain this speed n8 up to an angular position ϕ6. thereupon is decelerated again from the speed n8 to a speed n5 between the angular positions ϕ6 and ϕ7. The speed n5 is between the angular positions ϕ7 and ϕ8 are maintained and then between ϕ8 and ϕ9 accelerated again to a speed n7, which again during a plateau phase is maintained between ϕ9 and ϕ10. This plateau phase between ϕ9 and ϕ10 with the speed n7 corresponds to a further forming phase with another tool. Finally it is slowed down again by the speed n7 to a speed n4 between the angular positions ϕ10 and ϕ11, maintain the speed n4 up to the angular position ϕ12 and then accelerated again to a speed n6 in the interval between ϕ12 and ϕ13. The speed n6 is kept constant up to the angular position ϕ14. Then again to a maximum speed n9 between the angular positions ϕ14 and ϕ16 accelerate and the speed n9 during one Maintain the last forming phase between ϕ16 and ϕ17. Eventually at the end of the forming process between ϕ17 and ϕ18 braked to the original speed n2. We have 0 <n1 <n2 <n3 <n4 <n5 <n6 <n7 < n8 <n9.

As the profiles according to FIGS. 8 and 9 show, the angle-dependent allows Speed control according to the invention a variety of adapted roll rotation movements for different processes, tools and workpieces.

1 and 3 also show a worm wheel 9, which with the gear 18 for the work roll 2 is coupled and an adjustment or adjustment of the relative angular position of the work roll 2 relative to the work roll 3. It can adapt to different tools or also to correct the angular positions of the work rolls 2 and 3 relative can be adjusted to each other.

For setting or correcting the backlash or meshing between the roller gears 18 and 19 and the central control gear 5, an adjustment drive (not shown) can also be provided, which drives the Rotary drive with the permanent magnet motor 4 and the gear with the output shaft 45 and the control gear 5 relative to the two Roller gears 18 and 19 can move. This can create an asymmetrical Intervention or backlash can be corrected. Furthermore, it is possible separate drives for adjusting the rollers 2 and 3 with their Roll gears 18 and 19 are provided so that the meshing of the roller gears 18 and 19 to the central control gear 5 each independently can be adjusted from each other.

The holding devices 12 and 13 of the two work rolls 2 and 3 are carried by a carrier device 6 and stored or anchored therein.

The carrier device 6 comprises four column-like carrier elements 6A to 6D, which are arranged in a rectangular arrangement and on a common one Base plate 6E, which is supported on the floor 50, or attached. There is an associated tie rod in each of the carrier elements 6A to 6D 7A to 7B vertically in the longitudinal direction of the respective support member arranged, which is attached to the bottom of the carrier plate 6E and above by means of an associated lock nut, preferably a hydraulically operated one Lock nut (9B, 9C in FIG 3), is biased. Thereby, under the hydraulic nut a slotted backing ring segment placed when the hydraulic nut is in the released state and then by applying the hydraulic Pressure the nut pressed onto the washer segment. This can the carrier device, which forms the frame of the rolling machine, under one certain tension is set. This leads to a stiffening of the Rolling stand.

10 and 11 show a further embodiment of a cross wedge rolling machine 1, in which, in contrast to the embodiment according to FIGS. 1 to 3 a first drive 42 for the first work roll 2 and a second one from the first Drive 42 independent drive 43 for the second work roll 3. Everyone Drive 42 and 43 includes an associated permanent magnet motor 44 and 45 and a - not shown - gear, for example one, in particular three-stage, gear transmission, for transmitting the torque of the motor on the associated work roll 2 or 3. The reduction ratio each transmission can be 1:35, for example. In the illustrated 10 and 11 are the axis of rotation C of the Output shaft of the permanent magnet motor 44 of the first drive 42 and the axis of rotation D of the output shaft of the permanent magnet motor 45 of second drive 43 orthogonal to the axes of rotation A and B of the respective Work rolls 2 and 3 directed and the motors on the side accordingly Roll stand arranged.

Each of the permanent magnet motors 44 and 45 becomes electronic, in particular controlled by a converter. This allows the work rolls 2 and 3 either driven electronically synchronously or asynchronously become.

LIST OF REFERENCE NUMBERS

1

rolling machine

2.3

Stripper

4

drive motor

5

timing gear

6

support means

6A to 6D

support element

6E

baseplate

7A to 7D

tie rods

8A to 8D

guide

9

worm

9B, 9C

locknut

10

workpiece

12

holder

12A, 12B

part

13

holder

13A, 13B

part

14, 15

admission

16

feather

18, 19

gear

20, 21

Tool

23

recess

24, 25

extension

30, 31

Tool

33

recess

42, 43

rotary drive

45

output shaft

46, 47

Rotary drive gear

50

ground

60

positioning

61, 62

positioning parts

A, B

axis of rotation

C, D

drive axle

G

gravitational force

M

central axis

P

positioning

R

axis of rotation

w

tool clearance

W

Platen Gap

Claims (23)

Method for forming a workpiece, in which a) the workpiece is arranged between at least two rotating rollers equipped with tools and b) the rotational speed of at least one of the rollers is controlled or regulated as a function of the rotational position of at least one of the rollers. The method of claim 1, wherein the dependence of the speed of rotation on the rotational position of the roller (s) depending on the machined Workpiece is selected. The method of claim 1 or claim 2, wherein the workpiece a) is positioned between the rollers during a first process phase, preferably by means of a positioning device, b) is formed between the tools of the rolls during a second process phase and c) is removed or ejected again from the space between the rollers during a third process phase. The method of claim 3, wherein the rotational speed is in the first process phase is at least less on average than during the second process phase and / or the rotational speed of the rollers during the second process phase at least in Medium is greater than during the third process phase. The method of claim 3 or claim 4, wherein the workpiece at the beginning of the second process phase of the tool (s) at least one roller is detected and during the second process phase formed between the tools of the two rolls and at the beginning of the third process phase from the gap is ejected between the rollers. The method of claim 5, wherein the rotational speed after gripping the workpiece by the tools of the roller (s) in the second process phase is increased and / or in which the rotational speed before ejecting the workpiece in the third Process phase is lowered and / or at which the rotational speed when grasping the workpiece at the beginning of the second Process phase and at the end of the second process phase is approximately the same. Method according to one or more of claims 3 to 6, in which the speed of rotation of at least one of the rollers during the second process phase is kept at least partially constant or at which the rotational speed of at least one of the rollers during the second process phase, in particular according to a predetermined course or a predetermined dependency changed becomes. Method according to one of claims 3 to 7, wherein the second process phase includes individual sub-process phases, during which preferably the workpiece of various tools on the rollers is reshaped, before or after a sub-process phase and / or between the sub-process phases and / or during the Sub-process phases the rotation speed is changed and / or wherein the rotational speed before at least one or before each, sub-process phase is reduced. Method according to one or more of the preceding claims, at which the rotational speed and / or direction of rotation of the Rolls at least in phases essentially the same to each other can be set and / or at which the rotational speed and / or direction of rotation of the rollers at least in phases be set differently to each other. Method according to one or more of the preceding claims, where the current rotational position of the roller (s) from a starting position or reference position of the roller (s) and the course of the rotational speed is determined or at which the rotational position of the Roller (s) determined by means of at least one position detection device becomes. Method according to one or more of the preceding claims, at which the rotational speed at at least one rotational position is reduced to overstress the workpiece avoid this rotational position, and / or at which the rotational speed controlled or regulated in at least one rotational position is that the torque exerted on the associated roller assumes a predetermined value at this rotational position or not exceeds. Method according to one or more of the preceding claims, where the current position of the tools on the rollers is determined and a reference rotational position of the rollers depending on the determined current position of the tools is set. Method according to one or more of the preceding claims, in which the workpiece is cold formed or hot formed or is hot formed and / or in which the workpiece is made of an iron-containing one Material or from a non-ferrous metallic Material exists. Rolling machine, in particular for performing a method according to one of the preceding claims, with a) at least two rotatable or rotating rollers that can be equipped or equipped with tools for forming a workpiece that can be arranged or arranged between the rollers, b) at least one drive for driving the rollers,
in which c) the at least one drive comprises at least one permanent magnet motor, in particular a torque motor. Rolling machine according to claim 14, wherein each permanent magnet motor to the nominal speed for operating the roller (s) within a maximum rotation angle interval of at most 3 ° or accelerated at most 2.2 ° or at most 1 ° or even at most 0.5 ° or delayed. Rolling machine according to claim 14 or claim 15, wherein at least one or each permanent magnet motor has a nominal torque between about 5,000 Nm and about 80,000 Nm or between about Has 35,000 Nm and about 60,000 Nm and / or at least one or each permanent magnet motor has a nominal speed between about 20 rpm and 800 rpm or between about 30 rpm and has 500 rpm. Rolling machine according to one or more of claims 14 to 16, in which a common drive is provided for at least two of the rollers is, in addition to the at least one permanent magnet motor comprises at least one gear for transmitting the torque or the rotational movement of the permanent magnet motor to at least two rollers, preferably the gear at least one with the Central shaft output shaft of the coupled permanent magnet motor Drive gear and two meshing with the drive gear or bringable and coupled to one of the rollers Includes roller gears and / or preferably the gear ratio the gear from the drive motor to each of the rollers is the same or is in a range between 1: 1 and 1: 1.5. Rolling machine according to claim 17, wherein the backlash or the meshing of the roller gears to the drive gear is adjustable or can be corrected, preferably means for moving the drive gear, preferably together with the permanent magnet motor, are provided relative to the roller gears, in particular at least one adjustment drive. Rolling machine according to one or more of claims 14 to 18 with Means for adjusting the relative angular position of the two rollers to each other, preferably one coupled to one of the rollers Include worm gear. Rolling machine according to one or more of claims 14 to 19 and / or for carrying out a method according to one of claims 1 to 13 with a) at least two rotatable or rotating rollers that can be equipped or equipped with tools for forming a workpiece that can be arranged or arranged between the rollers, b) wherein each roller is assigned at least one drive for independently driving the rollers. Rolling machine according to one or more of claims 14 to 20, in which at least one drive has a converter for supplying the Has motor with electrical energy. Rolling machine according to one or more of claims 14 to 21, comprising at least one position detection device for detection or determining the rotational position of at least one of the rollers. Rolling machine according to one or more of claims 14 to 22, designed as a profile cross rolling machine or cross wedge rolling machine and / or in which the rollers are wedge-shaped in cross section or have triangular profile tools that run along the circumference increase in their radial dimension in one direction and / or run obliquely to the axis of rotation of the associated roller.

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