Method for rolling a ring-shaped rolling product having an open cylindrical cross section in a ring rolling machine, and ring rolling machine for carrying out the method

Abstract

A method for rolling a ring-shaped rolling product (5) having an open cylindrical cross section in a ring rolling machine (1) with inductive heating of the rolling product (5) during the rolling process uses at least one inductor (12) which is held at a predefined coupling distance relative to the rolling product (5) and is tracked or carried along during the shaping process in accordance with the change in dimensions of the rolling product (5). An alternating magnetic field, preferably with a frequency of between 4 and 10 kHz, is coupled directly into the rolling product (5) using the inductor (12).

Claims

1.-17. (canceled)

18. A method for rolling a ring-shaped rolling product (5) having an open cylindrical cross section in a ring rolling machine (1), comprising: holding an inductor (12) at a predefined coupling distance relative to the rolling product (5); moving the inductor (12) during a rolling process in accordance with a change in dimensions of the rolling product (5); coupling an alternating magnetic field directly into the rolling product (5) using the inductor (12) and thereby inductively heating the rolling product (5) during the rolling process; detecting an actual distance of the inductor (12) to the rolling product (5) by tactile sensing during the rolling process using at least two sensing rollers or at least two spacers (16) that are in engagement with an outer circumference of the rolling product (5); and automatically controlling the coupling distance as a function of the actual distance.

19. The method according to claim 18, wherein the alternating magnetic field has a frequency between 4 and 10 KHz.

20. The method according to claim 18, further comprising: positioning and holding the inductor (12) on an outer circumference of the rolling product (5) during the rolling process.

21. The method according to claim 18, further comprising: moving the inductor (12) in a controlled manner by at least one linear movement and one rotary movement on at least one movement axis.

22. The method according to claim 18, wherein coupling the alternating magnetic field directly into the rolling product (5) takes place in a direction of rotation of the rolling product (5) in front of a main roll (2) or an axial roll arrangement of the ring rolling machine (1).

23. The method according to claim 18, further comprising: coupling a further alternating magnetic field directly into the rolling product (5) using a further inductor.

24. The method according to claim 23, wherein the inductor (12) is arranged in front of a main roll (2) and the further inductor is arranged in front of an axial roll arrangement of the ring rolling machine (1) relative to a direction of rotation of the rolling product (5).

25. The method according to claim 18, further comprising: guiding the inductor (12) on a support arm (11) which has three degrees of freedom.

26. A radial or radial-axial ring rolling machine (1), comprising: a driven main roll (2); a mandrel roll (3); at least two axial rolls (8); means for centering a ring-shaped rolling product (5); and an inductor (12), the inductor (12) having at least two spacers (16), which can be brought into engagement with an outer circumference of the rolling product (5) and thereby specify a defined spacing of an induction coil (15) with respect to the outer circumference of the rolling product (5), wherein a position of the induction coil (15) is adjustable with respect to the spacers (16), wherein the inductor (12) is positioned at a predefined coupling distance to the rolling product (5) on an outer circumference of the rolling product (5) and moves according to a change in dimensions of the rolling product (5), and wherein the inductor (12) induces an alternating magnetic field with a frequency between 4 and 10 kHz in the rolling product (5) during a rolling process.

27. The ring rolling machine according to claim 26, wherein the inductor (12) is fastened to a support arm (11) of a manipulator (9) that is movable in three degrees of freedom.

28. The ring rolling machine according to claim 26, wherein the inductor (12) is fastened to a support arm (11) of an axial stand (10) of the ring rolling machine (1).

29. The ring rolling machine according to claim 26, wherein the inductor (12) is arranged in front of the driven main roll (2) or the at least two axial rolls (8) in a direction of rotation of the rolling product (5).

30. The ring rolling machine according to claim 26, wherein the inductor (12) is arranged in front of the driven main roll (2) and wherein a further inductor is arranged in front of the at least two axial rolls (8) relative to a direction of rotation of the rolling product (5).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a perspective view of a ring rolling machine,

[0032] FIG. 2 is a top view of the ring rolling machine, and

[0033] FIG. 3 is a perspective representation of the inductor.

DETAILED DESCRIPTION

[0034] The ring rolling machine 1 shown in the figures comprises a driven main roll 2 along with a roll table 4. The rolling product designated 5 is designed as a closed ring or as a cylinder that is open on both sides, as the case may be. The rolling product 5 has a rectangular cross sectional profile and rests on the roll table 4. The rolling product 5 is rolled between the main roll 2 and the mandrel roll 3 in a clockwise direction, reducing the wall thickness radially and at the same time reducing the height axially. In this case, the rolling product 5 is centered in the ring rolling machine 1 by means of centering rollers 7 fastened to swivel arms 6. Axially, the rolling product 5 is rolled by means of two axial rolls 8. The axial rolls 8 are designed as conical rolls and are mounted in an axial stand 10. The axial stand 10 can be displaced or adjusted, as the case may be, with respect to the center point of the rolling product 5, which shifts during the rolling process as a result of the increase in the radius, namely radially with respect to the rolling product 5.

[0035] In the exemplary embodiment described, a support arm 11 is fastened to the axial stand 10, and an inductor 12 is arranged at its distal end, which is directed radially inwards with respect to the rolling product 5. As mentioned above, the inductor 12 can alternatively be fastened to an articulated arm of an industrial robot, which is positioned around the circumference of the ring rolling machine 1.

[0036] The inductor 12 comprises a transformer unit 14 arranged on a base plate 13 and an induction coil 15, as can be seen in FIG. 3. The transformer unit 14 is connected to a capacitor cabinet, which is not shown, via air-cooled and/or water-cooled cables and provides the electrical matching of the induction voltage to the output voltage of a frequency converter. The frequency converter operates in a frequency range between 4 and 10 kHz. Furthermore, two spacers 16 are arranged on the base plate 13, between which the induction coil 15 is located. The spacers 16 are designed as sensing rollers extending parallel to the axis of rotation of the rolling product 5, the roller heads 17 of which are held in engagement with the rolling product 5 during the rolling process. The spacers 16 are water-cooled. Coolant ports 18 are provided for the aforementioned spacers 16, through which coolant flows

[0037] The induction coil, the transformer unit and the spacers 16 are arranged on the base plate, so that they can be adjusted both linearly and rotatably. Since, as described above, the radius of the rolling product 5 increases during the rolling process and, as a result, the distance between the induction coil 15 and the rolling product 5 would increase, a further linear adjustment is provided between the spacers 16 and the induction coil 15. Adjustability ensures that the distance between the induction coil 15 and the rolling product can be kept constant.

[0038] In order to be able to guide and hold the inductor 12 at a constant close coupling distance to the outer circumference of the rolling product 5 during the entire rolling process, the support arm 11 is furthermore radially displaceable with the axial stand 10 with respect to the rolling product. During the rolling process, the height of the rolling product 5 will decrease on the one hand, and on the other hand the diameter of the rolling product 5 will increase, such that the support arm 11 must be adjusted radially at least with respect to the rolling product 5.

[0039] The induction coil 15 shown in FIG. 3 has an approximately L-shaped cross sectional profile that extends under a part of the underside of the ring-shaped rolling product 5. The induction coil can also have a different geometry. It is not necessary that the induction coil 15 extends under the underside of the ring-shaped rolling product 5.

LIST OF REFERENCE SIGNS

[0040] 1 Ring rolling machine [0041] 2 Main roll [0042] 3 Mandrel roll [0043] 4 Roll table [0044] 5 Rolling product [0045] 6 Swivel arms [0046] 7 Centering rollers [0047] 8 Axial rolls [0048] 9 Manipulator [0049] 10 Axial stand [0050] 11 Support frame [0051] 12 Inductor [0052] 13 Base plate [0053] 14 Transformer unit [0054] 15 Induction coil [0055] 16 Spacer [0056] 17 Roller heads [0057] 18 Coolant ports