Integrated All-electric Tube Bender And Cutter Delivers Competitive Advantage To Volume Tubular Part Manufacturers

The machine's all electric, servomotor-controlled architecture gives comprehensive programmability throughout the entire part fabrication cycle. The position and forces of the tube bending dies can be precisely controlled, as can the movement profile and torque applied during the 'nick and shear' cutting cycle - delivering the highest accuracy and quality of shape fabrication and end finish. Servomotor control also ensures that cutting positions are extremely accurate and repeatable from batch to batch - to within +/- 0.1 mm (0.004 inch) - as tubing remains under control of a high-resolution digital motion architecture throughout the operation. These benefits are in addition to the well-known returns of low energy consumption and quiet operation of all-electric motion control architectures, compared with traditional hydraulically actuated machinery.

After a bending operation, moving the tube to the shear tool position and making the cut takes typically 12-15 seconds. This compares with perhaps 60 seconds - plus the need for skilled labour - that would be required for handling, loading, set-up and cut-off when the same task is performed at a separate station. In addition to these fundamental throughput gains, Unison's new integrated machine means that many manufacturers will also be able to produce multiple parts from each length of tubing, providing another major boost to productivity.

Integrated bend-and-shear answers the needs of manufacturers of volume parts such as automobile exhausts and tube and pipe component shapes, says Unison's Alan Pickering. Compared with production processes based on separate bend and cut stages, we believe the time and labour savings will start delivering a payback on an investment after only a very short timescale - down to as little as a few weeks for multi-shift manufacturing companies.

The new machine is called the Breeze-Blade, and is capable of bending and cutting tubing with outside diameters of up to 76 mm (3 inches). It comes with a multistack (multiple on-machine tooling) facility for software-controlled changeover between parts batches, with the nick and shear tooling loaded into one of the tool positions.

Cut-off is performed in two steps. The bent tube shape is positioned automatically by the machine's servomotor-driven carriage, and a circular clamp grips the tube directly adjacent to the cutting position. The first tool strikes the tube to create a nick that penetrates around two thirds of the way through the tubing wall. The shear blade then drives through the tubing - with control over aspects such as acceleration, speed, deceleration and torque to suit the material and the tubing shape. This highly-controlled action ensures a high quality dimple-free cut with minimal burring. The clamp has been specially designed to ensure that cuts can be made close to a bend - to within approximately 6 cm (2.4 inches).