Industrial robots in action

More than 150,000 new industrial robots were sold in 2011, according to figures supplied by the International Federation of Robotics and it says that this is the highest number of sold robots ever recorded in one year. CEE reports on a few robot projects.

A pioneering system for machining steering consoles offers a good example of how cost efficient and productive modern automation can be. Time consuming handling processes have been dispensed with in favour of machining directly on the work piece carriers in a solution offered for one customer by systems integrator, Automation Robotic.

This concept, in combination with a fast six-axis MOTOMAN robot, has opened up new possibilities for faster cycle times. The application required four threads to be cut on high quality die-cast aluminum steering consoles, in addition to de-burring and polishing. On one of three possible variants also needs to be drilled. The quality of the machining is to be assured by means of suitable QA measures. “It sounds easy, and would in principle be easy to implement, but it becomes a challenge when stringent customer requirements with regards cycle times, availability, space requirements and ease of maintenance, which make this difficult to achieve using regular solutions,” explains Walter Schaffhauser, managing director of Automation Robotic GmbH. 

The individual stations are linked by a longitudinal transfer system, while the work piece carriers are guided back to the starting position in a space saving manner using two parallel tracks. “A striking feature of the system is the clear, space saving layout of the line with accessible stations, which were customer requirements,” said Schaffhauser. 

The technical challenge for the systems integrator was to clamp the die-cast consoles onto the work piece carrier with such precision that threads could be formed reliably with a specified tolerance of less than 0.1mm. For this purpose, the work piece carriers, together with the parts that are to be machined, are removed from the conveyor and pneumatically clamped. 

Once the threads have been formed, the machined parts continue their journey along the transfer system towards a MOTOMAN HP20D robot, which was chosen for its precision and speed.

The six-axis robot is employed at the last station in the line and performs final machining of the steering consoles. In addition to high precision, high speed was also necessary, as a number of tasks have to be performed within the target cycle time of 12 seconds. In a first step, the robot uses its double gripper to pick up two steering consoles from the conveyor and move them into a QA station where the threads are inspected by means of sensors. Once they have been given the all clear by the quality control system, the six-axis robot takes the two consoles to the polishing and de-burring station. Various operations are carried out here, including de-burring and polishing. Following completion of these tasks and the transfer of the steering consoles to a part cleaning system. 

The system is able to work around the clock in a three-shift operation. The target annual output is 850,000 units. 

“For this cycle time critical application we needed a very fast robot with maximum availability – and we have found this in the MOTOMAN HP20D. What we also like about this machine is its compact, streamlined design. Despite its small size, the six-axis robot has a considerable working envelope so that we can reach all stations with the robot. We were also convinced by the precision of the HP20D,” said Schaffhauser. 

Paint shop success
Automotive manufacturer, Aston Martin has specified ABB IRB 5500 robots for use in its basecoat and clear coat painting booths. 

Benefits of the robot include a large working envelope which made it possible to paint the complete car body, covering both the chassis and the bumpers attached at front and rear. 

Commenting on the application, Robert Low, account manager for ABB’s robotics business, said: “The IRB 5500 is ideal for this application. The robot has the longest reach in its class with excellent path accuracy and is combined with the ABB RB1000 electrostatic bell atomiser to achieve an even distribution of paint over the surface of the car, achieving consistent high finish quality and minimising the amount of paint required.”

ABB’s Integrated Process System (IPS), a closed loop process system, is said to ensure that both the robot motion and paint process control are precisely co-ordinated to provide optimum quality.

For the basecoat application, the robot is used in its cartridge bell system version, providing the necessary isolation of the high voltage that is directly applied to the waterborne paint droplets. The system ensures that each paint cartridge is filled with the required amount of paint, keeping waste to a minimum.