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Body sealing: it’s all done by robots01 September 2008All car body seam sealing, soundproofing and under body sealing operations at Jaguar’s assembly plant in Castle Bromwich are now accomplished by eight robots working across three cells. The installation replaces a traditional semi-automated manual sealing operation that often required downstream remedial interventionJaguar has transformed traditional car body seam sealing, soundproofing and under body sealing operations at its assembly plant in Castle Bromwich, by installing a fully automated six-axis robot-based facility. The investment has helped the car maker move away from an intensive manual labour-based operation to an all-robot-based system incorporating eight ABB industrial robots.
This fully automated facility requires no operator intervention during normal operating conditions. The absence of manual intervention – or ‘no-touch’, to use the jargon – minimises the post-operation, remedial sealing that was often required with the previous traditional automated sealing method. ABB senior project manager, Robert Low takes up the story.
“The automation of seam sealing and associated operations is a major investment for this plant, and a significant and timely step forward in optimising the efficiency of the Jaguar paint sealing process. The investment has helped establish consistently high levels of quality while almost eliminating what was a labour intensive and unpleasant job.”
ABB personnel from the UK and Germany were jointly responsible for this turnkey project, which included the acquisition and installation of the car body conveyor, roller beds, spray booths, robots, track motion, sealant dispensing systems, sealant storage system, guarding and control systems. In addition, the company provides local support, including the provision of service parts, training, start-up assistance and a site-resident engineer.
Body sealing in action
Operation of the facility is split into three separate sealing stations. The facility can process the complete range of Jaguar car bodies, including the XK sports car, the S Type and the XJ saloon, both standard and long wheel base. The skid-mounted car bodies pass through three stations. At the first station, the three seam sealing robots spray a PVC plastisol material at a temperature of 30ºC within the interior and luggage compartment spaces of the body, to seal against water ingress and wind noise.
Three IRB 4400 robots, which have a 45kg payload, have an exceptionally long reach, which allows them to enter each car body to access the body seams. The robots are mounted on linear track systems to further increase their flexibility.
Two of the robots conduct sealing operations from either side of the rear passenger compartment, then track forward to access the forward passenger compartment, while a third robot tracks across the rear of the body, sealing the luggage compartment.
After seam sealing, the car bodies are transferred to the next station, where three IRB 4400 robots spray an epoxy-based, solvent-free material, at a temperature of 60ºC, to reduce noise, vibration and harshness. Being able to spray this sound insulation material is a breakthrough for Jaguar as previous methods involved the manual application of bitumen pads.
After seam sealing and the application of sound insulation materials, the car bodies move on to an under cell, incorporating two IRB 2400L robots with a 10kg payload. As the body moves through the station, the robots carry out a combined seam sealing and under-body coating operation, applying the same PVC plastisol used for internal seam sealing. Once the under-body sealing application and curing is complete, the car bodies move on for the application of primer, base coat and clear coat.
All eight robots are equipped with standard ABB DispensePac dispensing systems that incorporate both material conditioning and flow control. ABB Swivel Pointer Applicator spray guns are used throughout, each of which is equipped with three separate nozzle types that can be individually selected, depending upon the area to be sprayed. For example, a wide ‘fan’ configuration is required for coating areas, while seams need a very narrow, flat stream. The switch from one nozzle to another is co-ordinated by the ABB robot controller.
Positioning accuracy
The positional accuracy of each car body skid is +/-15mm, which was deemed insufficient for quality purposes. In the end, a vision system was incorporated to locate the car body in relation to its ideal datum position, which then transmits data to the robot controller to offset the positioning of the robots by the required margin. Additionally, the under-body robots are equipped with ‘conveyor tracking’ software and encoder input, so that they can determine the exact position of the carrier as it moves through the station. If the carrier moves faster, slower or stops, the robot will offset its program to track the movement accordingly. Contact Details and Archive...Related Articles...Most Viewed Articles... |
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