The Land Rover Freelander 2 is not, by any definition, an entry-level model. Yet the new Range Rover Evoque, which borrows its layout from the Freelander, has undergone a series of major revisions in terms of its manufacturability in order to achieve the ‘premium’ feel that the management at Jaguar Land Rover (JLR) believes buyers of a Range Rover would expect to encounter.
Graham Miller, Evoque Launch Manger at JLR’s Halewood plant in Liverpool, UK, explains further: “As a plant, we had a good reputation for building the Freelander, but we needed to understand the gap to premium product requirements. We had to ensure that we achieved leadership in perceived quality; touch, feel, hearing, sense, everything about the car that speaks of quality, our customers would likely be coming out of other premium vehicles.”
As new models are launched into production, Miller goes on to explain that some manufacturers record an appreciable increase in warranty issues. Not so, he says, between the withdrawal of the first Freelander (built from 2002 - 2005) and the introduction of Freelander 2 in 2007. Using the company’s Launch Quality Operating System, Miller points out that despite the natural disruption caused by introducing a new model, the company recorded the highest level of early customer satisfaction across all JLR brands, which he planned to continue with the Evoque.
This meant that there were various issues that needed to be addressed in order to achieve a seamless model launch, not least of which was the use of aluminium body panels in the new model.
“In terms of new tech, we recognised that one of the key challenges included the use of lightweight materials,” says Miller. Unlike the Freelander, the Evoque features roof and bonnet parts pressed from aluminium. “The aluminium roof is joined to the steel body using rivets, supplied by Henrob and Tucker. We had to go through quite a long learning curve with regards to riveting, we’re now using self-piercing rivets which go through the aluminium and into the steel.” Having addressed the joining issues, Miller says that he needed a solution that would eliminate any chance of corrosion occurring between the two materials. “You can get water into these joints, but there must not be any electrolytes in the water. Exhaled moisture from within the cabin is fine, but rain water can carry salts into the joint.” Miller says that unlike other carmakers, which generally use manual processes to achieve such joins, the process is mostly automated for production of the Evoque. “In one area, redundancy is built in through each robot making a seal on one side of the car, with a duplicate on the opposite side. Every part has two sealing attempts.” He adds that vision systems are used to confirm the integrity of the sealant bead.
The process effectively adds additional e-coat to these joints, creating a curtain between the two parts. For added protection, a ‘flowable’ sealer is added in the paintshop. “It’s quite old-fashioned technology, we haven’t attempted to do anything too advanced, but this is a reliable process. It’s redundant, and on top of that, the sealer added in the paintshop flows into the cracks and crevices. We get a good, all-round seal and we’ve not had a single leak from those joints over the programme.”
In addition to three CMM machines, Halewood also has ‘e-cubes’ for the three- and five-door versions of the Evoque. Machined from aluminium billet, these solid master gauges are used to test a full range of parts, from outer skins and trim parts through to sub- and full-body assemblies. As Miller points out, the e-cubes even include representations of the clinch flange for the door, which is machined directly into the material: “It’s as perfect as you can get,” he says.
He further explains that while the e-cubes act as benchmarks, the plant operates two levels of part co-ordination, covering whether the parts co-ordinate with each other and whether they co-ordinate with each other when attached to the car. “A good example of this is the door casing. If the door casing is away from nominal, it might fit when you clip it into place on the e-cube, but a steel door might exhibit some deflection in it. As [the e-cube] is solid, it assumes that the part is on nominal. So you might find that over the first stage it does work, but at the second stage, when the panel is attached to the body, you might find that a nominal steel panel has some distortion in it; as it distributes that load it creates a deflection. So we check at the first stage on the e-cube and then, after the part is assembled, [the body] is audited for quality, looking for gaps, wrinkles and blemishes.” Such imperfections would then be fed back to the vendor for corrective action.
Although Miller says that such attention to detail is apparent in such features as panel gapping, he highlights the fact that it would be impossible to achieve acceptable repetition without first perfecting the underbody. “It’s one thing to say we’ve matched all the panels, but it starts with getting the underbody right. That’s your foundation, and in some cases the keystone for other parts.”
Looking back, Miller says that his team spent a lot of time achieving the required dimensional stability in the underbody, particularly with regards to the ‘snowshoe’ and rear longitudinals, as these parts influence the width of the car and the geometry of the chassis. “Get the underbody and part co-ordination right and you are effectively applying the parts in an unspotwelded condition to make sure they match in an unloaded state. You don’t want a spotweld to have to pull something into line, you want it to match in its free state.”
This is of the highest priority when dealing with door closures, as the seal gaps for wind and water, together with the feel and shut effort, are vital to achieving the required level of perceived - and actual - quality. To address this, Martin Wall, Dimensional Assurance Engineer, says that the hinges are first bolted to the body before the doors are applied. “We use a ‘Nummi’ jig that locates to the master on the side, and that is located onto the rear of the B-pillar. We put the hinge to the body and use shoulder bolts to attach the door to the body. This allows us to achieve the same positioning every time.” Graham Miller adds that it is the dimensional accuracy of the underbody that allows this to work, delivering identical reference points on every vehicle, while corrective action loops were used to guarantee the assembly process.
Asked if the Evoque could have been brought to production without the Freelander coming before it, Graham Miller says that it could have been done, but the bodyshop has driven the viability of the project through investment efficiency. “In terms of underbody, there are a lot of unique parts, but [both models] go through the same underbody complex, and the bill of process is common.”
Like the underbody, the suspension of the Evoque could be described as an evolution rather than a revolution. As Miller says, the theme is more similar than different. There are, though, some key differences here as well, such as the aluminium steering knuckles, but the overall suspension architecture layout remains largely unchanged.
What has changed in terms of Evoque is how the overall manufacturability of the vehicle has been improved to reduce the chance of variation between individual vehicles. As an example, Miller highlights the work done on the vehicle’s rear quarter, where the light cluster, bumper and body panels meet. “Originally, the bumper was located to the underbody, and the tail lamp was located to the upper body, but you would see a variable gap. We had a bracket, but we couldn’t find a way to get it to relate to the upper body panels as it comes all the way down from the roofline - it wasn’t feasible to grow the panel. Before final data judgement, the locator started lower and gradually moved higher as we tried to pull the parts together. Now, if you remove the tail lamp, you’ll see the bumper bracket is pinned to the same panel as the lamp, the bodyside, and everything related to it.
“Trying to locate things to the same master datum in Z, in this case, was a real push for manufacturing, as we don’t want to have setting processes; we want to have the master locater define the position. In reality, you want to have as many things as possible come to the same locator.”
The Evoque and the Freelander 2 are both manufactured over the same assembly process at the JLR Halewood plant. In order to accommodate the second model, various automated processes have had to be revisited in order to provide the flexibility to deliver both vehicles in any given production mix.
Graham Miller explains that the first step in adapting a given station is to create a three-dimensional cell simulation. “We worked with the [Evoque] designers in the virtual phase, delivering lessons learned, making sure that the parts assembled on-screen would be manufacturable in the assembly process.” A physical mock up of the cell was then built off-site to prove out what was anticipated in the 3D simulation. “We were taking people to Gaydon (Land Rover headquarters) to go through the build process by process, looking at the build cycles in BIW and trim and final, doing the assembly of the different panels and parts.”
This was the development process behind the new framing station, details of which are shared by John Wilson, Maintenance Superintendent for the Bodyshop. “The underbody is common to both vehicles, so that goes through a common robotic facility. In terms of bodysides, the vehicles are quite different, so we have dedicated bodyside facilities. For framing, this is a combined line. We have a flexframer facility, it’s a new technology brought on board for the Evoque, but it’s still part of the common line.”
Wilson explains that the flexframer was installed by ABB, and the same company also supplied the robotics, but an in-house team has been trained to reprogram the robotics as necessary. “The reason we went for the flexframer is because we’ve now got three- and five-door bodysides, and with this we can frame these in the same station. This also gives us long-term flexibility, where by if other projects come on line, this can handle different bodysides; it expands our capabilities.”
Data carried on an RFID tag alerts the flexframer as to which vehicle and bodytype is entering the cell. Wilson also points out that the same data is also available via the cell’s PLC (programmable logic controller), providing a ‘belt and braces’ approach to built-in redundancy. Instead of tacking the bodysides to the underbody (in which case the join would be completed in the respot area), the flexframer makes a full join between the underbody and bodysides. As such, it is critical that the dimensional integrity of the vehicles is verified; this is done using a laser-based system delivered by Perceptron.
In total, Wilson says that the bodyshop features about 500 robots, a smaller number than used in most plant to produce an equivalent number of vehicles. “It’s an integrated factory, so instead of heaving a dedicated facility for the underbody, we have 100 or so robots there to simply add the capability - it’s a two-for-one. To save time on framing, we have put some additional robots into the station, but we just needed a small addition to build both vehicles, another two-for-one.” He adds that while a higher number of robots could translate to reduced cycle times, the current takt time of 90 seconds is sufficient to deliver the proposed volumes.
The assembly line station where moonroofs and sunroofs are automatically installed also had to be adapted in order to produce the Freelander 2 and Evoque on the same line. Mal Burdett, Senior Manager for Manufacturing Engineering, says that one of the major changes was in the part delivery process. “The cell features a loading station where the operator picks the moonroof and manually loads the correct part. The parts are delivered in sequence, and scanned as the vehicle enters the station to make sure we’ve got the right cassette.”
Once the component is picked up - the system incorporates an ABB robot fitted with a gripping tool delivered by Expert Tooling and Automation - Burdett says that the first job is to apply adhesive. To do this, the component is rotated under a fixed nozzle that delivers a bead of polyurethane glue. “The adhesive bead is delivered in a specific shape, height and width. The cell constantly monitors this bead profile using cameras to measure the bead at 1,000 points around its path. It also has the ability to sense if there’s an air bubble in the adhesive product, it can tell if there’s a flow difference. If it detects a problem, it can present the glass to an operator so he can make sure that it’s OK before it’s decked to the vehicle.”
All cars, whether they are scheduled to receive a roof component or not, enter the cell, although Burdett says that the percentage of vehicles receiving the feature is very high. Carried on a skid, the car bodies are located to a known position, after which the system makes final adjustments that are measured in fractions of a millimetre. The system lines up the roof with the body using a camerabased measurement system, in a look, measure, scan sequence. Although the system is capable of decking a roof in less than 50 seconds, the current 70-second takt is sufficient to keep up with production.
As the glass is applied, Burdett explains that too much pressure could damage the adhesive bead, compromising the join and possibly allowing water ingress. To avoid this, the Expert gripping tool further features a series of pneumatic pressure valves located around its periphery. “If we were to apply too much pressure, the roof might recover (spring back) and rupture the bead, so we’ve worked out exactly what load we need to use to apply the roof.”
Burdett adds that beyond sealing characteristics, the adhesive also has structural qualities. “As we bond the roof into the vehicle, it adds torsional stiffness. It’s not just a piece of glass. It’s as strong, if not stronger, than a metal roof.”
While a similar cell is used to install glass roof assemblies for the Jaguar XJ, Burdett says that differences in the components and vehicles meant that JLR and the system integrators had to approach the cell as a completely new project. “There was a lot of fine tuning to get the cell functioning,” he says. “As more prototypes became available, we put more product through the cell, looking first for repeatability and then for reproducibility.” Overall, Burdett says that the positioning capability of the robots is “phenomenal”, while changing the adhesive application process has also been beneficial. “In the past, we had fixed glass and moving adhesive heads, but moving the hoses around - they’re fairly heavy - was never good practise.”
Interestingly, while the moonroof installation process is almost totally automated, standard glazing for both the Freelander and Evoque is completed by hand, as Graham Miller explains: “I don’t know what the breakeven point is, but at the moment we’ve gone down the low-investment route. There is an element here where the payback of an automated system can only be achieved at higher volumes and we’ll review that, based on numbers.”
As a production area, trim and final is not known for its depth of automation. Even in the most modern plants, only 15% of all operations in final assembly will be completed without human intervention. Yet one such assembly process that has been automated at JLR is the addition of door seals, as Mal Burdett explains: “When we were using stick-on, self-adhesive seals, we used a hard-tooled, pneumatic cell to install them. The seal was loaded by the operator into the pneumatic plates and pneumatic cylinders would squeeze them onto the door to complete the process. This new robotic technology is far more flexible.”
He further explains that similar to the moonroof installation system, the seal is delivered from a fixed point as the picked door is moved around the application point used to feed the seal. To complete the seal application process the joint, which is always positioned at the bottom of the door, is scanned by a laser and then cropped to size. The adhesive tape backing paper is removed by vacuum during the application process.
Pointing out that custom seamless seals are now available on the market, Graham Miller states that he would be open to looking into the technology, although he says it would be hard to beat the flexibility and control offered by the installation currently in place.
From its inception, the Range Rover Evoque has been designed as a vehicle that could be equipped to the customer’s exact specification. While this translates to a complex network of lineside part deliveries that must be made just in sequence, it also impacts on the paintshop, as the Evoque is also offered with a choice of contrasting roof colours.
To handle this option, Chris Arner, Paintshop Engineer, says that a completely new system has been installed next to the existing primer line, which is dedicated to applying the roof paint and related clearcoat layers. “The cars that are having a different colour added are picked off the line once the full paint process has been bought off and they’re taped up using special masking material.” The paint is applied in a booth delivered by Eisenmann, that uses robotics from Dürr that feature the EcoBell application system.
According to Arner, a single coat is sufficient to complete the contrasting roof application, unless the chosen colour is white, which means two passes must be made. After the paint is applied, the bodies are flashed and cooled before being clearcoated. Cars that will have the roof colour added are identified by data loaded on an RFID tag, while the masking is completed in a fully manual process.
Where as painting the roof is a fully-automated process, Arner points out that the full line still features some manual application processes. “The line was installed about 15 years ago, we still have manual processes for door shuts and other areas where the robot can’t access.” Despite this, he says that the paintshop is still fully capable of keeping up with current production numbers, which translates to approximately 50 jobs per hour. This will be aided by upgrading the PLCs running the paint equipment; where there were five, only one will be needed to do the job.
As for full paint customisation, Arner says that it’s not currently available, but it’s something that could be introduced at a later date. “The main line is not very suitable for that at the moment. If the demand was there for more colour choices, we could alter the facility to do this fairly easily.”
Graham Miller has been working at the Halewood plant since the last years of Ford Escort production, and was a part of the transition to Jaguar production in 2000. Since then, the plant has switched to production of Land Rover products, which has helped to secure the plant’s long-term future. “This is a plant reborn, based on three key elements.
One is lean production, the second is culture change and the third is quality.”
Has badging the Evoque as a Ranger Rover product made the build more difficult, in that customers expect more from a Range Rover than a Land Rover? “We’re driven to a level of perceived quality that is intended to be a leadership level. It’s down to capability, better design. It’s not something you can sprit in at the later stages, so it’s been embedded right from the start.”
