The tube bending industry is seeing a migration from more traditional manual hydraulic process equipment to fully automated "all-electric" machinery. Historically, tube bending operations have been labour intensive, noisy, and slow with sometimes-dangerous factory processes that also often had serious issues with repeatability and quality. This is all changing with the advent of automated equipment, creating opportunities to maximize productivity, product accuracy, and yield, as well as reducing downtime associated with the changeover.
Automated electric processes have the inherent ability to operate around the clock and, through utilisation of sensing and measuring various parameters, maintenance can be planned and unexpected downtime avoided. Additionally, through the use of pre-programmed recipes for common tube sizes and bend patterns, quick and seamless change-over can be achieved, further reducing costly machine downtime.
These factors help make higher volume tube bending requirements a prime candidate for automation in contrast to other manufacturing activities where there may be fewer clear advantages to making the investment or where specific process steps make it difficult. Automation also removes the requirement for skilled or semi-skilled operators due to the availability of simpler control and operation systems that need minimal supervision.
The automation of multi-axis tube bending machines requires high quality, high accuracy linear and rotary motion control technology in order to achieve the necessary degree of accuracy and repeatability. The latest low inertia, low cogging servo motors, rodless linear actuators, high force electric cylinders, and drive controlled pumps can achieve this. They precisely manage aspects of the bending machine operation, such as tube transportation, vertical and horizontal carriage movement, mandrel rotation, and workpiece clamping, with greater accuracy and control than was possible with previous technologies – manual or automated.
The operation and status of the various linear and rotary actuators can be overseen, and rapid changeovers achieved, through the use of high-performance interfaces and dedicated machine and motion control modules. This allows users to achieve maximised first-run yield and part accuracy, as well as higher overall machine throughput than traditional solutions.
Another recent advance has been the way in which bending machines are wired. Clearly the interconnection of the large amount of motion control hardware described can require significant amounts of wiring and complex cable solutions. Traditional multi-cable solutions can be complicated and space consuming to implement and difficult or complicated to maintain.
Single digital cable servo motors can be implemented and integrated with the latest digital servo drives and positioning technology. This can help the speed and simplify this aspect of bending machine design, build, and operation. Single cable servo motors can also reduce associated costs and enhance overall system reliability as well as supporting digital feedback control.
Article contributed by Henry Claussnitzer, market development manager, Industrial Applications, Electromechanical Drives Division Europe, Parker Hannifin Corporation.