Automatic tool changers have come a long way
The introduction of industrial robot technology as a production tool revolutionised many manufacturing processes by improving productivity, consistency, and quality, in addition to relieving human operators of some of the most repetitive, difficult, and even dangerous tasks.
As the benefits of robotics became widely accepted, users strived to take advantage of the flexibility that robots offered by seeking to configure robotic cells to handle multiple products and perform several different operations. The limiting factor in many cases was the need to manually change end effectors to accomplish these different tasks. The time taken however to re-configure the robot for the new task, often resulted in lengthy periods of downtime for the robot. As a result, many robots remained dedicated to their single original application.
The advent of the automatic tool changer opened up new possibilities and provided robots with a significant increase in flexibility. Also, the time taken to change end effectors was reduced from the many minutes needed for a manual tool change to just seconds, allowing the robot to maximise productive time. Although fully functional, early robot tool-changers were somewhat basic, with limited connectivity capability for services, in many cases, just pneumatics and signal power. These first-generation systems proved the concept, even if the areas where they could be beneficial were limited.
Fast forward to today, and just as industrial robots have evolved significantly, along with the introduction of collaborative robots, tool-changers themselves have now reached far higher levels of sophistication.
Whether it’s for a high payload robot in the automotive sector changing spot welding guns, or smaller robot systems performing multiple handling or assembly operations, today’s tool-changing technology now makes it possible to achieve the original aim of maximising the flexibility offered by the robot.
One firm working on new developments in this field is Stäubli. The company’s MPS robotic tool changers, reportedly increase the productivity for robots in all payload categories from all major manufacturers.
Compared to the limited functionality of early day tool-changers, Stäubli’s latest generation systems offer numerous different modules for the transmission of pneumatics, vacuum, signals, data transmission up to 10Gbit/S, shielding, earthing, RFID tool coding and data storage. The ability to combine these different technologies and modules makes it possible to configure a solution for a wide range of applications. The location of the transmission modules is also highly flexible, allowing users to position them as required to suit the individual robot’s cable package. The robot mounted component of the MPS Tool Changer incorporates all the services required to provide functionality for the various tools which may be used by the robot in production. On the tool change element, the only transmission modules required are those relating to the operation of specific tools. This makes it possible to use multiple, individually configured tool elements with one robot mounted element.
Cross-shaped guide surfaces combined with a spring-loaded ball locking system are used to achieve interconnection between the robot and tool sides of the MPS tool changer system. This makes it possible to maintain precision throughout its product lifecycle. The tools always return to their original insertion position with a repeat accuracy of +/-1.5 µm.
Stäubli tool changing systems are available for robot payloads up to 1530kg and attach directly to the ISO standard flange of every robot produced worldwide, without the need for an adapter. This drilling pattern is also the same on the tool side for ease of installation.
Stäubli’s range of Tool Changer technology comes in three options. MPS COMPLETE offers preconfigured robotic tool changers for immediate use. MPS MODULAR allows the user to determine the configuration, while MPS CUSTOMIZED allows the construction of special, application-specific systems.