Following the successful installation of a turnkey system to position, insert and bond the panoramic glass roof to the aluminium body of the stunning new Jaguar XJ, Expert Tooling proposed a similar system to install sunroofs for the exciting new Range Rover Evoque and the Land Rover Freelander 2 at the JaguarLandRover (JLR) plant in Halewood.
Working with its materials conveying partner Exmac Automation, the Expert engineering team liaised with the same JLR engineering team they had worked with at the Jaguar Castle Bromwich facility.
The original concept for the system came from the Jaguar Advanced Manufacturing & Engineering (AME) department and, because the Evoque was to have a new roof rather than a carry-over from the Freelander, the Halewood roof installation cell needed to be replaced with a new, fully automated cell that would accommodate three car variants – three door and five door Evoque models and the current Freelander 2. Based on the AME brief, five companies were invited to quote for the new facility and, from a shortlist of three the Expert-Exmac partnership was awarded the contract based on a combination of value and experience and their technological solution, which best met the needs of the existing production facility and was designed to avoid disruption to ongoing or future assembly line operations.
The partners – Expert specialising in robotics, precision tooling and gluing systems and Exmac in conveying, transfer systems, automation and control – worked closely with the Jaguar team to prepare a detailed simultaneous engineering project for the Freelander 2 and Evoque sunroof insertion system.
The Exmac conveyor system accommodates six vehicle platens and features three powered roller beds (PRBs) and an accumulator conveyor. In addition, the middle roller bed of the power roller conveyor also incorporates a clamping, lifting and centralising mechanism designed to fix the car in the optimum position for the vision system used to locate the roof fixing holes for the robot controlled roof insertion system designed by Expert.
Reinforcing the sense of déjà vu, the new roof system also involved cutting into an existing assembly line to enable the installation of the new body transfer system and the roof insertion cell, but there the similarity ends. The Jaguar roof ‘floats’ into position on the XJ’s body, whereas Evoque and Freelander 2 sunroofs are located using pins. And while the flowing lines of the XJ prevented the use of a vision system to position the glass roof, the Halewood installation proved to be an ideal candidate for a camera-based system, enabling a sunroof to be fitted every 85 seconds.
Freelander 2 and Evoque roofs are unloaded from stillages onto the sequence build schedule using a specially designed assistor, which rotates the roofs through 90 degrees to enable an operator to fit the correct antenna. The roof is then rotated back to its original position and loaded onto the Exmac accumulating conveyor, which returns it to the sequence build schedule. A vehicle body enters the cell from the pre-trim twin strand conveyor onto one of the PRBs at process speed and is verified against the sequence build schedule using a TAG reader verification system and body identification sensors.
A ‘Roof-on’ unload station within the cell is also verified using a barcode reader; and when both roof and body are confirmed the body is carried on the Exmac fast-transfer PRB to the cell PRB where the body transport skid is centralised, lifted off the rollers and clamped. The robot’s gripper adjusts to suit the correct roof model and collects the roof from the accumulating conveyor platen where it is held in place with vacuum pads. The platen then returns to a lower level, allowing the next roof to enter the cell. Before entering the cell, the moon roof is pre-heated in order to prolong the life of the glue (by approximately one minute) to assist in the location process. The robot then moves the roof under the PU application nozzle and a specially formulated adhesive is applied.
The adhesive bead is measured during the application process and, when the process is completed the robot moves the body into position to enable the cell’s camera system to confirm the positions of the holes used to locate the roof. If a ‘Not OK’ signal is received when the bead is measured the roof is moved to a standby position for manual inspection. If the application is subsequently accepted manually, the process continues.
However, if it is manually rejected, the roof is loaded onto a reject trolley located within the cell, which has the capacity for a maximum of three roofs.
As mentioned, unlike the Castle Bromwich system where the XJ’s glass roof is positioned and inserted using mechanical centralising methods and robotic techniques, the Halewood plant uses a camera vision system. Expert’s Terry Davidson explains: "The absence of sharp body features on the flowing lines of the XJ made it difficult for a vision system to operate effectively. However, for the Land Rover bodies the vision system is the preferred option as the roof is located using pins, which fit into location holes in the roof. The vision system is designed to measure the roof aperture, locate the holes and adjust the programming of the robot to enable it to fit the roof based on the measurements."
The offset positions identified by the vision system are fed to the robot, enabling it to move to the correct ‘roof-fit’ position. The robot then lowers the roof pins into the body location holes and releases the roof. Load units designed specifically for either the Evoque or Freelander 2, apply a five-second ‘squeeze load’ to the pre-set sunroof location points. The load units then retract and the robot returns to a ‘Pounce’ position above the roof platen to await the next roof.
With the roof installation completed the skid-mounted body is released and lowered onto the Exmac conveying system for fast-transfer out of the cell and onto a pre-trim conveyor, also at process speed.
Commenting for Exmac, managing director Gary Sweeney says: "We are delighted to be involved in a successful partnership with Expert to help create a second exciting new vehicle for JaguarLandRover."
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