African Fusion March 2015

Robotic automation

Robot welding, catalytic converters and PE SA’s benchmark city for robotic automation

African Fusion visits the Port Elizabeth robotics fa- cilities of Yaskawa Southern Africa, takes a tour of a local state-of-the art catalytic convertermanufac- turing facility, and talks to Dale Palmer of Yaskawa PE about the city’s vibrant automotive component manufacturing sector and its increasing use of robot-based automation.

A ccording to the MD of a PE-based catalytic converter manufactur- ing facility, South Africans are “na ï ve” about its capability. “We are much more advanced than people perceive,” he says, adding: “Within the global group, this company is viewed as a benchmark, not only for our capa- bilities, we are also the go-to company when there are problems in other parts of the world. We export our talent, abili- ties and locally developed solutions.” In particular, this MD cites develop- ments from its PE-based automation and system integration partner, a com- pany that, in association with Yaskawa and the local catalytic converter indus- try, is pioneering modularisation solu- tions. “As far as robotic automation is concerned, South Africa is up there with the best of the world and this is clearly evident from the export success of our local automation partner, which is ex-

porting 12 modular integrated handling andwelding cells from PE inSouthAfrica toEurope,” he tells African Fusion .

Dale Palmer of Yaskawa PE.

Also, while volumes are relatively high, the mark-up allowed by catalytic con- verter (CAT) manufacturers is next to nothing. And as contracts are extended, the prices per CAT paid to the manufac- turer actually reduce,” reveals Palmer. “The only way to meet these conflicting requirements is to use expensive jigs to hold the part duringmanufacture and to do the welding using robots,” he adds. “While the capital up-front costs might be higher, once the system is running, the unit costs drop quickly because you can push volume through the system without sacrificing quality.” Describing how simple CATs for vehicles aremanufactured, Palmer says that catalytic converters have a ‘can’ as the central component that contains the expensive catalysing materials in a honeycomb-structured element. “Typi- cally, a cone is welded onto one side of the can, then the part is turned around for the opposite cone to be attached. Then stud pipes with their flanges are added. From an automation point of view, there are several pieces being joined, access is poor and assembly has to be done progressively,” he explains. At the heart of a typical welding cell is a set of progressive jigsmounted onto a Motoman RM2 rotating manipulator. While welding is taking place inside the cell, a completed part is removed from the jig on the far right and each partly assembled part is shifted one jig to the right. New component pieces are added and the empty jig on the left is filled. On completion of each welding cycle, the manipulator rotates, advancing the process for each part by one step.” Six distinct steps are performed by two

The design and manufacturing complexity of catalytic converters “has increased exponentially”, according to Yaskawa’s Dale Palmer. The welds and welding angles, weld penetration profiles, fusion techniques and materi- als are all more complex, which places increasing pressure on manufacturers to deliver a quality product without jeopardising costs or productivity. To ac- commodate this complexity, the robots used in the catalytic converter industry for handling and canning are now often integrated into the welding cell. “Vehicle manufacturers have very stringent quality requirements: consis- tent penetration; low levels of spatter; smooth weld profiles; and very low distortion and dimensional accuracy.

At the heart of a typical welding cell is a set of progressive jigs mounted onto a Motoman RM2 rotating manipulator.

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March 2015

AFRICAN FUSION