ABB has developed an innovation called ‘Force Control for machining applications’ which it has incorporated into a new Flex Finishing Cell.
The result is an easy to use technology for flexible and efficient production that challenges the traditional way a user programs a robot.
ABB sales manager Olivier Coquerel says the introduction of three Force Control (FC) functions, FC Graphical Programming Interface, FC Press and FC Speed Change adds a new dimension to the use of robots in machining operations.
“The Flex Finishing Cell will be of particular benefit to casting companies, particularly those doing small production runs, as Force Control features reduce the robot programming time by approximately 90 percent.”
The conventional way in which a user programs a robot, is to define the path and the speed. These will be constant, independent of the process forces.
If the path does not coincide with the surface and dimensions of the part, you will instantly have quality problems and potential damage to the tooling.
This is a known fact in the robotised finishing process, with users having to spend a lot of time trying to correct these deficiencies with additional flexible toolings and servo axes often needed. Force Control for machining applications changes this:
* FC Graphical Programming Interface enables the operator to move the robot by hand to the correct positions defining the path and save these. The correct positions on the work piece (part) will only need to be accurate within a few millimetres. The manually taught paths will now be used as the basis for Automatic Path Learning. The robot will run FC Pressure functionality and follow the surface/edge and at the same time record the accurate path.
* FC Pressure makes sure the robot always follow the surface as the tool travels along the programmed path. The path can be linear or circular. The robot position perpendicular to the path direction will be changed continuously in order to maintain the force (contact pressure to the surface).
o FC SpeedChange keeps the process forces constant by changing the robot speed when the burr along a part line changes. This keeps the material removal rate below a maximum value when the depth of cut is increasing.
The new cell developed by ABB takes advantage of these new dimensions, and the benefits that Flex Finishing offers are:
* Ease of use – fast integration due to the shorter programming, tuning, and cycle times.
* Quality improvement in production with a reduced risk of damage to work pieces, tools and robot.
* Improved working conditions with minimised injury and health risks for personnel.
* Lower costs due to the predictable tool wear and extended tool lifetime.
* Higher productivity with the ability to handle variations in location of burrs and flashes.
* Better process results due to the ability to control the process force, not the positions.
Flex Finishing Cell is a complete package which represents a standardised, verified robot solution in the form of a robotised cell, which can be programmed for different tools and adapted to different components and work objects.
The ABB Flex Finishing Cell package includes:
* An IRB 140 industrial robot.
* Function Package Force Control Machining.
* A manual 2 station turntable.
* A 2-metre high, 2-metre wide base plate including cell housing.
* The spindle.
* Tool buffer for use up to 5 tools.
* Graphical User Interface (GUI).
* Human Machine Interface (HMI).
Force Control feature is available also for ABB robot models IRB2400, IRB4400, IRB6600 and IRB7600, available throughout Australia from ABB Certified Robot Partners.