TPT July 2011

T echnology U pdate

H1, H2 and H3 tube piercing

H1 and H2 tube piercing are applications in which the holes being punched are dimpled only. Unlike the punching method, piercing does not use an internal mandrel and die sections to keep the tube from dimpling, but instead it uses external guides to encapsulate the tube. This keeps the OD of the tube consistent while the punch pierces into the hollow tube drawing material around it and forming a dimple. H1 refers to a dimpled hole on one side, while H2 refers to a dimpled hole on both sides, or what is commonly referred to as a double dimple. Multicyl provides a standard system for both H1 and H2 applications for tubes up to 1.5" diameter, and custom systems for larger tubes. An H1 system is easily converted to an H2 system by adding a punch assembly to the bottom guide in the standard tool set. H3 tube piercing refers to applications in which the tube is pierced straight through 12" and 16" five roll welding stands THE new large size mill welding stand from Oto Mills is designed to integrate rigidity, simplicity, quick roll changeover and easiness of roll setting. The configuration is a typical five roll weld stand: Nr 2 squeeze rolls, Nr 2 top inclined rolls and Nr 1 bottom support roll. For small tubes the welding stand can be fitted with only four rolls (two squeeze and two top), while the bottom roll is cylindrical and used as vertical support for the squeeze rolls. Special features include slide guide of squeeze rolls located on the back of squeeze rolls to avoid contamination/accumulation of weld spume and projected particles; quick changeover cassettes – top and squeeze rolls are assembled in cassettes for quick changeover; and simplified roll changeover with top tilting frame. The top frame tilts back by hydraulic cylinders to leave space for replacing the squeeze rolls with an overhead crane. The

with one punch. Although classed as a piercing application, it is actually a hybrid between piercing and punching, as the top side is pierced as described above in the H1 and H2 section, but the bottom hole is actually punched from the inside out as the punch travels through to the bottom of the tube and punches the bottom hole against an external die. Multicyl straight through tube pierce stations produce a through hole that is dimpled on the top and clean on the bottom. Maintenance may be higher with this application, as the punch tip is significantly longer and the bottom hole is actually punched with the slug from the top hole. hydraulic locking cylinders guarantee a strong and rigid configuration. The design has been optimised with special consideration of the welding induction process, in order to maximise the efficiency of energy transfer from coil to the edges to be welded. The back of frame is designed to allow easy access to the inside scarfing unit, for insert replacement. The main features for adjustments are: adjustment of squeeze rolls with AC gear motors and absolute encoder/transducer; vertical adjustment of bottom roll with AC gear motors and absolute encoder/transducer; separate vertical adjustment of top rolls with AC gear motors and absolute encoder/ transducer; simultaneous self centring transversal adjustment (to suit width of weld bead) with AC gear motors; simultaneous transversal adjustment for alignment of top rolls across mill centreline with AC gear motors; top frame of squeeze box is tiltable downstream for squeeze roll replacement; tilting cylinder and hydraulic locks in working position fitted to the bottom squeeze box frame; rolls shall be supplied completely assembled with shafts, bearings and seals; and top roll forks with quick changeover system. A similar design is used on the smaller 12" size with hydraulic motors and absolute encoder as option. Multicyl Inc – Canada Fax: +1 905 951 0672 Email: sales@multicyl.com Website: www.multicyl.com

AGENTS REQUIRED

Oto Mills SpA – Italy Fax: +39 0522 964188 Website: www.otomills.com

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J uly 2011

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