What is Machine Tending?
Machine loading and unloading can be an extremely intricate application and can be the most complex in the whole of the materials handling system.
Robots integrated efficiently can be a key business differentiator that provide a means for companies to survive, grow, win orders, increase quality and output, and remain competitive.
Usually, one robot can perform the work of three to five people, reducing the cost of labour in the machine tending area. Among the direct benefits that a company can realise is reduced wastage, increased machine capacity, and reduced OH&S issues.
Among the indirect benefits is the reduction of operator error due to predictable machining processes. With the ability to perform a variety of tasks and achieve a mean-time-between-failure of more than 60,000 hours, robots are also more advanced than traditional automation process systems such as linear gantries.
In Machine Tendering the robot has to provide both the transport and the manipulative capabilities. Robots can be used to take hold of a component from a supply point (e.g., a conveyor belt), transport it to a machine, orient it, and then insert it into the machine holder. This may require that the robot signal the machine tool when the component is in the correct position, so that the part can be secured in the holder. The robot then releases the part and withdraws the arm so that machining can begin its work upon the component. Upon completion of the machining, the robot unloads the component and transfers it to another machine or conveyor. In a robotic cell, a single robot can service several machines. The single robot may be used to perform other operations while the machines are performing their primary functions. This may require that the robot be able to exchange end-effectors.
Examples of machine tending functions include the following:
• Exchanging machine tools, such as lathe and machining centres
• Stamping press loading and unloading
• Tending plastic injection moulding machines
• Holding a part for a spot welding operation
• Loading hot billets into forging presses
• Loading auto parts for grinding
Camera vision also helps simplify part presentation and part recognition. It allows the customer to present a wide range of components to the robot, eliminating huge fixturing costs. Vision offers flexibility for future components to be integrated into an automated system. The robot system must also allow an operator access to make tooling adjustments and manual operation when required.
Multiple machine load/unload, inspection, and secondary operations can also be combined and automated as part of the machine tendering development.
• Conveyor line.
Parts can be brought to an automated System via an existing or new conveyor line allowing you to streamline the process.
• Robot transfer unit - floor or overhead
This allows the robot or robots to move linearly along a track for multi - position to accommodate 2 or more machines or work stations.
• Index Tables / Positioners
Parts can be presented to the robot and manual part loading / unloading without interrupting the robot operation.
End-of-Arm-Tooling (EOAT) design is yet another consideration. It is defined by part size, weight, gripping location, gripping surface quality, throughput, and work holding device interference zones. Many grippers used for machine tending applications are off-the-shelf pneumatic parallel motion types with two or three jaws depending on the part’s shape at the gripping location. For sheet metal fabricators wanting to automate a sheet-handling process, the robot gripper is designed with simple vacuum cups mounted on extruded aluminium frame.
When working with a multi-axis robot, application software has also been simplified to the point that users with little or no experience can program a robot. Today’s programs are provided in plain English and use drop-down menus to select commands or functions.
However guarding and safety are important aspects that should be reviewed and understood by everyone involved in the design, implementation, and production of a robotic system.
Machinery Automation & Robotics
1/101 Derby Street
Silverwater NSW 2128
Phone: (61) 2 9748 7001
http://www.machineryautomation.com.au