Robotic tube bending cell designed for high-volume applications

Unison has developed Uni-vercell, an automated tube bending cell suitable for high-volume applications such as automotive. Available in North America through Horn Machine Tools, the cell is designed to provide a complete loading, end forming, bending, and vision inspection process in the footprint typically required for a stand-alone tube bending machine, according to the manufacturer. It incorporates all-electric machine architecture centered on an articulated robot arm.

The machine fabricates tubular parts with diameters up to 3/4 in., sitting in a 48-sq.-ft. footprint. It includes a tube loader, a six-axis robotic arm with a 13.23-lb. payload, a two-stage end former, a multistack tube bender with no mandrels, and an integrated vision system that allows the cell to operate unattended with 100 percent inspection of bend angles and end-form shapes. The system's programmability simplifies integration of functions such as product labeling, which can be fitted into the free vertical space.

The articulated robotic arm replaces the carriage of other tube bending machines. Adapting the arm with a collet for gripping and rotating the tubular part, the arm holds and manipulates the part continuously through all stages—pickup, end forming, bending, inspection, and final release—to eliminate the carriage and the space required for the carriage bed, as well as intervening reference points, jigs, and handling equipment.

The machine also incorporates an all-electric end former to provide software-controlled, two-stage end forming; the stages are flaring and compressing. According to the company, the end former is designed to eliminate the pump and tubing, as well as the associated heat, noise, energy consumption, and environmental issues.p

The system can fabricate parts to an overall accuracy of 0.004 in. and accommodates complicated shapes, reports the company. Although the cell is designed for repetitive-volume applications, operators can configure the robot arm for batch production as well. A closed-loop electronic control helps ensure accuracy and repeatability. Drift-free performance allows operators to set up the machine by loading a program instead of making trial parts.

The cell is designed for continuous use, and its typical energy consumption is about 1.5 kW, the company reports. It incorporates the company's front-end software, Unibend, and teaching software supplied with the robot. After the operator programs bends and end forms by inputting data such as position, angle, rotation, and torque, the machine sets up automatically. All required intervening movements can then be programmed by positioning the arm manually and capturing the data.