Tuesday, 9 September 2014

Jaguar XE: “as strong and light as possible”

Jaguar’s XE sports saloon is the lightest, stiffest and most aerodynamic saloon car the company has ever built, the company claims.

It is also the first Jaguar to be equipped with electric power steering, tuned to provide “exceptional responsiveness and feel” but with “lower energy consumption than hydraulic systems”.

The XE boasts the lowest cost of ownership of any Jaguar and is also the most environmentally sustainable.

The aluminium-intensive Jaguar XE is manufactured at JaguarLandRover’s Solihull plant in the West Midlands in an all-new purpose-built facility. Part of a £1.5 billion investment, this highly flexible, state-of-the-art manufacturing site will create 1,700 UK jobs.

The XE now completes the Jaguar saloon car range sitting below the XF and XJ models.

The Jaguar XE was developed in parallel with the new modular architecture. The architecture “unlocks design possibilities” that did not exist before because the core dimensions were determined by design and engineering working together from the outset, under a philosophy of “anything we can imagine, we can create”.

This strategy, according to Jaguar, makes it possible to realise “perfect proportions”: short front overhang, longer rear overhang and dynamic, cab-rearward stance. The architecture also enables the XE to feature both a low, sporty driving position and a sleek, coupe-like profile.

Jaguar claims to be “more experienced in the use of aluminium construction than any other vehicle manufacturer”. The unrivalled expertise in working with this lightweight material has culminated in the revolutionary body structure of the new XE.

It is the first model designed around Jaguar’s all-new modular architecture and is the only car in the class to use an aluminium-intensive monocoque.

Much of the aluminium for body-in-white (BIW) is high-strength, 6000-series alloy. The one-piece bodysides are complex pressings. Previously, Jaguar might have used 1.5mm gauge sheet; this has been reduced to 1.1mm – with no loss of stiffness, according to Jaguar.

This has had important implications for metal joining. Jaguar uses Henrob’s self-piercing rivet technology, a technology that has evolved over the years.

The new XE has been engineered to meet the most stringent legislative and consumer crash test requirements worldwide, including US and Euro NCAP. The deployable aluminium bonnet ensures high levels of pedestrian impact protection.

Sustainability is a major aspect of Jaguar’s aluminium strategy. Recycling this highly valuable material delivers impressive savings in overall CO2 emissions and the new XE is the first car in the world to use RC 5754 – an aluminium alloy made predominantly from recycled material.

Future models will also use RC 5754 and this breakthrough will push Jaguar towards its goal of using 75 per cent recycled material by 2020.

“The XE is as strong and light as it could possibly be thanks to exhaustive analysis and by bringing the latest engineering techniques to bear on its design. It has been challenging to accomplish but the XE’s structure is absolutely at the cutting edge of what is achievable today,” noted Dr. Mark White, Jaguar's Chief Technical Specialist; Body Complete.

Dr. White has witnessed at first hand the evolution of aluminium BIW structures since the appearance of XJ, the first of Jaguar’s production cars to use Henrob’s self-piercing rivets. White has also seen the growth of in-house aluminium stampings as the company increasingly has installed press lines to accommodate this material which requires clean working conditions.

The new XE has the most sophisticated chassis of any vehicle in its class and Jaguar claims it will set the benchmarks for ride and handling: it is a true driver’s car.

Where most competitors use MacPherson strut front suspension, Jaguar’s vehicle dynamics team insisted on the superior double wishbone configuration. The aluminium front knuckles are forged from cast blanks using a patented production process.

Conventional multilink rear suspension could not deliver Jaguar’s dynamics targets, it is claimed. The solution was integral link: a system usually found only in larger, more expensive vehicles and which delivers lateral and longitudinal stiffness values needed for the XE’s precise handling and supple ride. Aluminium has been used extensively, minimising weight.

Electric power steering (EPAS) offers tuning potential and greater energy efficiency than traditional hydraulic systems but Jaguar’s engineers have not considered the technology sufficiently mature – until now.

Prototype development using larger vehicles convinced the dynamics team that the best EPAS technology could now deliver the advantages of fuel consumption reduction without any loss of feedback through the steering wheel.

The XE is the first Jaguar to use EPAS. As well as reducing CO2 emissions by up to three per cent, the system offers the performance that Jaguar’s engineers demanded.

No comments: