TPT September 2018

T E CHNOLOG Y

Development of welded, thick wall, small diameter tubing for the automotive industry

KUSAKABE Electric & Machinery Co Ltd was founded in 1916. Since the early 1960s Kusakabe has been an innovator and adopted of new technologies in the development of machines for the manufacture of welded tubes and pipes. The company’s continuous investment in research and the automotive market’s constant demand to reduce the weight of automobiles have helped Kusakabe to become a leading company in providing tube mills that enable the replacement of solid bar with tubular products and the replacement of seamless manufactured tubing with welded tubing. Kusakabe has worked to master ad- vanced forming and welding techniques in order to manufacture extremely thick wall, small diameter tubing to become a leader in this technology for the automo- tive industry. A Kusakabe designed and manu- factured tube mill owned by a German customer is currently producing tubing from 25.4mm to 76.2mm diameter and wall thickness from 1.5 to 8mm. As an example, this tube mill produces 76.2mm diameter by 8mm thick tube from steel with a yield strength of 800Mpa, running at a maximum of 60mpm and producing cut lengths from 6 to 12m. This tube mill consists of a double- sided uncoiler with coil opener, a strip leveller, a shear and a weld station that also punches a hole in the strip to identify it and enable the automatic tracking of the cross welds. There is also an automatic weld bead removal station. The cross weld is annealed before being fed into a vertical strip looper (accumulator). One of the advantages of the vertical looper is that the strip edges are protected from wear and damage, preserving the slit edge condition for consistent weld quality. The forming mill consists of the conventional Kusakabe

The Kusakabe-designed machine

The tube then enters the modular sizing mill, which has an extremely strong frame and contains three rolls, with each covering 120° of the tube profile. A double cut flying shear is used to cut the tube to length without leaving cutting debris inside the tube – a critical requirement for the drawn tube operation that follows. The tube is end faced with OD and ID chamfers using a high-speed, servo motor-controlled end facing machine that can process 20 tubes per minute. Kusakabe has a long history of providing machinery to the tube and pipe industry. The company’s aim is continued investment in research while working in partnership with its customers. Kusakabe Electric & Machinery Co, Ltd – Japan Fax: +81 78 992 9139

heavy-duty stands mounted on quick- change sub bases. Each shaft on each stand is independently driven by its own motor. The seam guide is mounted on a sliding base, which is used to fine tune the vee angle as the strip approaches the squeeze stand for welding. The squeeze stand has a two-roll configuration with back-up rolls for extra rigidity. Included are load cells that provide constant feedback and monitoring. Internal weld-bead removal is achieved using electromagnetic technology for adjustment and support. There is no bottom support wheel that would otherwise roll welding debris into the internal surface of the tube. External weld bead removal is achieved using tandem cutting tools with the weld bead being wound onto a spool. After welding the tube is air cooled and then water cooled to control the mechanical properties of the weld seam.

Email: sales@kusakabe.com Website: www.kusakabe.com

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SEPTEMBER 2018