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

A ring rolling machine (1) for rolling a ring-shaped rolling product (5), the ring rolling machine (1) comprising:

• a driven main roll (2);
• a mandrel roll (3) disposed opposite the driven main roll (2),
• wherein the ring-shaped rolling product (5) is receivable and rollable between the driven main roll (2) and the mandrel roll (3);
• at least two axial rolls (8) arranged on opposite sides of the ring-shaped rolling product (5) and configured to engage the ring-shaped rolling product (5) in an axial direction to reduce a height thereof,
• wherein the axial rolls (8) are conical rolls mounted in an axial stand (10);
• centering rollers (7) fastened to swivel arms (6) and configured to engage an outer circumference of the ring-shaped rolling product (5) to center the ring-shaped rolling product (5),
• wherein at least two centering rollers (7) are arranged on opposite lateral sides of the driven main roll (2) and bear against the outer circumference of the ring-shaped rolling product (5) during rolling;
• and
• an inductor (12), the inductor (12) comprising
• an induction coil (15) configured to inductively couple an alternating magnetic field with a frequency between 4 and 10 kHz into the ring-shaped rolling product (5) to heat the ring-shaped rolling product (5) during rolling,
• two sensing rollers (16) configured to remain in engagement with the outer circumference of the ring-shaped rolling product (5), and to detect an actual distance between the ring-shaped rolling product (5) and the induction coil (15), the two sensing rollers (16) being
• disposed on opposite lateral sides of the induction coil (15),
• wherein a position of the induction coil (15) is adjustable with respect to the two sensing rollers (16),
• wherein the induction coil (15) is positioned at a predefined coupling distance from the ring-shaped rolling product (5) and moves according to a change in dimensions of the ring-shaped rolling product (5).