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
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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.
Claims15
A cold pilger rolling mill for cold working a hollow into a strain-hardened tube comprising:
- a roll stand comprising 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 front reversal point in a feed direction of the hollow and a rear reversal point in the feed direction of the hollow, and wherein the rollers during a reciprocating motion of the hollow perform a rotational motion, such that the rollers in an operation of the cold pilger rolling mill roll the hollow into a tube, a mandrel, wherein the mandrel is supported by a mandrel bar at a rear end of the mandrel bar in the feed direction of the hollow in such a way that during operation of the cold pilger rolling mill the hollow is rolled by the rollers over the mandrel, at least one feed clamping carriage with a feed chuck mounted thereon to receive the hollo, wherein the feed clamping carriage in a direction parallel to the longitudinal axis of the hollow is movable back and forth between a front reversal point in the feed direction of the hollow and a rear reversal point in the feed direction of the hollow such that the hollow in an operation of the cold pilger rolling mill experiences a stepwise feed in a direction towards the mandrel, and wherein the feed chuck can is openable and closeable in a radial direction in such a way that it releases or clamps the hollow, and
- at least one mandrel thrust block with a chuck mounted thereon to hold the mandrel bar, wherein a front mandrel thrust block is positioned in front of the feed clamping carriage in the feed direction of the hollow such that the mandrel bar in an operation of the cold pilger rolling mill is holdable by the chuck of the front mandrel thrust block, and wherein the chuck of the front mandrel thrust block is openable in a radial direction, so that a hollow is feedable between the chuck and the mandrel bar,
- wherein the front mandrel thrust block has a distance of at least 30 m from the feed chuck, measured with the feed clamping carriage at its rear reversal point.
A method for manufacturing a tube by cold working a hollow in a cold pilger rolling mill with a roll stand having rollers rotatably mounted thereon, a mandrel supported by a mandrel bar, at least one mandrel thrust block holding the mandrel bar and at least one feed clamping carriage with a feed chuck to receive the hollow comprising the steps of:
- a) opening a chuck of a front mandrel thrust block in the feed direction the hollow 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 a 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 at a front reversal point of the feed clamping carriage in the feed direction of the hollow,
- d) rolling of the first hollow by the rollers over the mandrel into a strain-hardened tube by stepwise feeding of the first hollow by means of the feed clamping carriage and an oscillating motion of the roll stand with the rollers back and forth between a front reversal point and a rear reversal point, wherein the first hollow has a length of 30 m or more.
Dependencies are inferred from the claim text.