ALPHR and Omron Utilise Innovative SCARA RobotNovember 28, 2012
A leading automotive parts manufacturer recently asked the experts here at ALPHR Technology to automate the assembly of a moulded plastic spigot. Their requirements were simple – they wanted a solution which would be cost-effective, compact, reliable and easy to access. However, the necessary processes to reach this solution were not simple and, after careful consideration and thorough analysis, the professionals at ALPHR concluded an Omron SCARA robot, used in conjunction with a vision system and other Omron automation products, would definitely be the best way to meet their requirements.
As experts in the automotive industry, the client largely specialises in designing and producing precision injection-moulded parts and they have been supplying injection-moulded spigots to a leading automobile manufacturer for an impressive amount of time. In the past, assembly of the spigots had been a largely manual process, but when an increase in demand for the spigots meant the need for an additional production line, the company decided to investigate the possibility of automated assembly.
In essence, the assembly process involves fitting four compression limiters of two different sizes to the spigot. The limiters have to be accurately positioned and pressed into place to a precisely defined depth. Once fitted, they have to be retained with a specified force. The final stage of the process is to carry out a leak test on the completed spigot assembly to verify not only that the limiters have been fitted correctly, but also to check the integrity of the part itself.
Following detailed discussions, the experts here at ALPHR proposed a machine with a PLC-controlled rotary assembly station, which would produce one completed part every 20 seconds. It would only require one operator, who would need to load the parts into the machine, and everything else would be conducted automatically, including inspection, testing and the delivery of the finished part to either the pass or fail bins.
ALPHR Technology gave further consideration to the meticulous details of the machine, and finally concluded that a machine using conventional multi-axis pick-and-place technology would be complicated to design and build, inflexible, and ultimately difficult to maintain. A solution based on an Omron SCARA robot would, however, solve all of these problems as well as addressing a requirement for the machine to have the smallest possible footprint.
Also, after taking the cost of the machine into consideration, including the price of all equipment and materials as well as the entire design and construction, the Omron robotic solution proved to be a much more cost-effective, financially attractive option. These factors made the Omron robotic solution very exciting but, even though the client had a wealth of experience using large, multi-axis robots, it had no previous involvement with SCARA robots. Therefore, before making a significant investment in the new machine, the company needed assurance that it would perform as predicted.
Application engineers from Omron provided this assurance by using sophisticated software to imitate the operation of the proposed assembly machine. This not only confirmed that the principle of operation of the machine was sound, but also that the required cycle times and efficiencies could be easily achieved. The highly successful demonstration answered any questions or queries the client had and also managed to dispel any of their concerns, meaning they now gave complete authorisation for the project to progress.
The impressive and incredibly innovative spigot assembly machine was built and worked by producing a part that was first loaded manually into one of the ‘nests’ in the machine’s rotary assembly table by the operator. A pneumatic cylinder then pushes the part fully home where the table indexes. Next, the robot takes the four compression limiters, one at a time, from vibratory feeders and places them into the part.
Two Omron FQ vision sensors confirm that the limiters are all present and correctly positioned, and then the table indexes again, moving the part to a station where the limiters are inserted with Pneumatic cylinders and then a force push out test is carried out by applying a precisely controlled force.
The table indexes once more to bring the part to the final station where it is pressurised and tested for leakage. Depending on the results of the test, the part is transferred either to the pass bin or the fail bin, the latter being kept behind a locked door within the machine to ensure that defective parts can never be accidentally mixed with good products. Passed and failed parts are automatically counted, and the machine notifies the operator when the bins are ready to be emptied.
Paul Bridgwater, sales manager at ALPHR Technology, said:
“Understandably, as this was the company’s first machine with a SCARA robot, they kept a close eye on this project, so I’m delighted to say that it went very smoothly. Programming the robot was straight-forward and it worked ‘straight out of the box’, as did the vision system and all the other key automation components supplied by Omron.”
The new spigot assembly machine has now been working on site for several months, and is fully living up to expectations. While, as planned, the rate of production of the new machine is not substantially different from that of the manual assembly line, the percentage of reject parts is greatly reduced, as the dependable robotic placement of the compression limiters and the 100% inspection by the vision sensor’s make it virtually impossible for incorrectly assembled parts to go forward to the final testing stage.
The specialists at ALPHR are incredibly pleased with the results the Omron SCARA robot has provided and, as they are completely dedicated to constant development and innovation, will work hard to ensure these results only ever get better. So for more information on any of the services we provide, including our advanced robotic automation solutions, get in touch with the friendly and highly experienced team at ALPHR Technology today!This entry was posted in News. Bookmark the permalink. ← ALPHR go to Stuttgart for the Motek International Trade Fair An ALPHR Christmas! →