Cold pilger rolling mill and method for producing a pipe
AssigneeSandvik Materials Technology Deutschland GmbH
InventorsChristofer Hedvall, Udo Rauffmann, Thomas Froböse
Life of this patent
Estimating the term…
Abstract
A cold pilger rolling mill including a front mandrel thrust block that has a distance of at least 30 m from a feed chuck, measured with the feed clamping carriage at the rear reversal point thereof. The distance is measured between the rear (in the feed direction of the hollow) end of the chuck of the front mandrel thrust block and the front (in the feed direction of the hollow) end of the feed chuck of the feed clamping carriage at the rear reversal point thereof.
Claims16
A cold pilger rolling mill for cold working a hollow into a tube comprising:
- a roll stand comprising a plurality of rollers rotatably mounted on the roll stand, wherein the roll stand is driven by a motor and is movable back and forth in a direction parallel to a longitudinal axis of the hollow between a roll stand front reversal point and a roll stand rear reversal point, the roll stand front reversal point being in front of the roll stand rear reversal point in a feed direction of the hollow, and wherein, during a reciprocating motion of the hollow, the rollers perform a rotational motion, and wherein, in an operation of the cold pilger rolling mill, the rollers roll the hollow into the tube,
- a mandrel, wherein the mandrel is supported by a mandrel bar located, in the feed direction of the hollow, at a rear end of the mandrel bar so that during the operation of the cold pilger rolling mill the hollow is rolled by the rollers over the mandrel,
- a first feed clamping carriage with a feed chuck mounted thereon to receive the hollow, wherein the first feed clamping carriage is movable back and forth in a direction parallel to the longitudinal axis of the hollow between a first feed clamping carriage front reversal point and a first feed clamping carriage rear reversal point, the first feed clamping carriage front reversal point being in front of the first feed clamping carriage rear reversal point in the feed direction of the hollow, wherein, in the operation of the cold pilger rolling mill, the hollow experiences a stepwise feed in a direction towards the mandrel, and wherein the feed chuck of the first feed clamping carriage is openable and closeable in a radial direction to release or clamp the hollow, and
- at least one mandrel thrust block with a chuck mounted thereon to hold the mandrel bar, wherein the at least one mandrel thrust block includes a front mandrel thrust block with a front chuck, the front mandrel thrust block being positioned in front of the first feed clamping carriage in the feed direction of the hollow, wherein, in the operation of the cold pilger rolling mill, the mandrel bar is holdable by the front chuck of the front mandrel thrust block, and wherein the front chuck of the front mandrel thrust block is openable in a radial direction so that the hollow is feedable between the front chuck and the mandrel bar,
- wherein the front mandrel thrust block is at a distance of at least 30 m from the feed chuck of the first feed clamping carriage, measured with the first feed clamping carriage at the first feed clamping carriage rear reversal point.
A method for manufacturing a tube in a cold pilger rolling mill with a roll stand having rollers rotatably mounted thereon, a mandrel supported by a mandrel bar, at least a front mandrel thrust block holding the mandrel bar, and at least a first feed clamping carriage with a feed chuck, the method comprising the steps of:
- a) opening a chuck of the front mandrel thrust block in a radial direction and feeding a first hollow through the front mandrel thrust block,
- b) after completely feeding the first hollow through the front mandrel thrust block, closing the chuck of the front mandrel thrust block in the radial direction such that the front mandrel thrust block holds the mandrel bar supporting the mandrel,
- c) feeding the first hollow to the first feed clamping carriage and receiving the first hollow by opening the feed chuck in the radial direction and clamping the first hollow by closing the feed chuck in the radial direction, wherein the feed clamping carriage is at a first feed clamping carriage front reversal point,
- d) rolling the first hollow by the rollers over the mandrel into the tube by a first hollow rolling process that includes stepwise feeding of the first hollow by means of the first feed clamping carriage, and an oscillating motion of the roll stand with the rollers, wherein the oscillating motion of the roll stand with the rollers moves the roll stand back and forth between a roll stand front reversal point and a roll stand rear reversal point,
- wherein the front mandrel thrust block is at a distance of at least 30 m from the feed chuck of the first feed clamping carriage, measured with the first feed clamping carriage at a first feed clamping carriage rear reversal point, and
- wherein the first hollow has a length of 30 m or more.
Dependencies are inferred from the claim text.