Renault Mégane

High-quality components and equipment features developed
The Mégane is Renault’s flagship in the compact class and is therefore a strategic model series for the French car maker. With a share of more than one third on the European car market, this market segment is still the one with the largest production volume. As a development partner for interior and exterior components and features, Bertrandt has set innovative accents for its customer Renault with this project, which offers considerable potential for the future.

The Mégane forms the core series in Renault’s model range and is available in different versions: 4-door and 5-door saloon, coupé, estate, coupé-cabriolet and two compact MPV versions, the Scénic and Grand Scénic. From 2006 to the end of 2008, Bertrandt was responsible for developing and controlling the geometrical stability and dimensional accuracy of interior and exterior equipment features and components as a project partner. The Bertrandt teams were employed at Renault’s “Technocentre” location in the metropolitan area of Paris and worked closely with Renault and its suppliers to develop the optimum solution that fulfilled both design and construction requirements – and to deliver the results on schedule. These requirements were reliably implemented: the Mégane saloon and the coupé were launched in January 2009, while the Scénic and Grand Scénic compact MPV versions came onto the market in the spring of 2009.

Cockpit – successfully setting milestones
The Bertrandt teams were involved in the development, quality strategy and technical validation of the cockpit. This is produced in two main versions – one for the saloons and the coupé and one for the MPVs. Furthermore, electric locking for the glove compartment is provided for the estate and coupé-cabriolet versions. For the cockpit, the focus was on innovation. Instead of a plastic base material, the cockpit is made of a 12 mm compound material finished using SLUSH technology, which produces soft surfaces that are pleasant to the touch. A further specification by Renault to the design department required a new design language for the air vents, the implementation of which at the interface to the cockpit proved to be a demanding task. For the two Scénic models, Renault had also specified that all information instruments for the driver had to be arranged in the centre of the cockpit. This requirement was fulfilled by the use of a very elongated instrument cover that offers protection against reflection and therefore guarantees good visibility. A further technical speciality of the project was that the steering wheel should not only offer vertical adjustment but also be adjustable for reach. As a result, the shell below the steering wheel must conceal all technical components in all possible steering wheel positions.

A further highlight: Renault took the opportunity to use this development to introduce a new sound system generation that sets new standards. The milestones and schedules were reliably adhered to. A particularly positive aspect for Bertrandt was that, when the project was completed, Renault expressed its full satisfaction with the service provider’s performance. The first cooperation between Bertrandt and Renault in the area of the instrument panel is already being continued in the form of on-going cooperation with the car maker’s cockpit department.

Exterior development with experimental approaches
Bertrandt was also given responsibility for the pre-development and development of the front apron and exterior add-on parts, as well as the wash/wipe function and the lights. The body design required completely different technical performance features. This demanded an overall new development, in some cases with experimental approaches, in order to comply with the new standards, corrosion protection requirements and assembly specifications. The development of the front apron in particular was strongly influenced by new standards for pedestrian protection. The aim of the work was to optimise the front apron in order to comply with crash requirements in the lower leg/thigh and thigh/hip areas. Energy absorption tests with 500 joules for impacts at the height of the leg and 700 joules at hip height confirmed the soundness of the calculations carried out by the Bertrandt team. This standard also had influences on the development of the cowling grille and the windscreen wiper mechanics. Connecting these two elements on the passenger side required a special innovation: in order to guaran-tee a perfect leak-proof seal between the grille and the wipers, the team designed an element that is mounted on the wiper arm and provides a seal with the cowling grille by means of a compound moulded rubber sealing component. As a result, the element remains fixed in relation to the grille but at the same time allows the wiper arm to move inside. Special attention also had to be paid to a side connection component developed under the project name OLGA (OLGA = obturateur latéral de grille d’auvent/side cowling grille seal). This forms a connection between the cowling grille, the windscreen and the pillar. Normally, the body design department is responsible for these components. In the Mégane series however, OLGA production also includes a plastic component, which is why the team had to achieve a viable compromise between the requirements of different departments when designing the parts. The result is a reliable and effective component with an appealing design and flawless execution.

Controlling geometrical stability and dimensional accuracy – focus on the process
From December 2007 to January 2009, one Bertrandt team was given responsibility for controlling the geometrical stability and dimensional accuracy of the two Scénic models. Its task was to guarantee product feasibility on the basis of continuous processes. In the development phase, the technical validation of the design proposed by Renault was performed with the aid of dimensional chains. Subsequently, the development of special control instruments enabled each individual component to be quality tested. During the prototype phase, the Engineering department was also given responsibility for supplier management for the various intermediate stages. The first components, including body components, were then assembled in practice. During this phase, the geometrical joinability was confirmed to ensure that no problems occur during assembly. Wherever required, action plans were determined with the suppliers involved in order to directly rectify any component defects. The parts quality is tested using a special tool developed by Renault. As soon as the specified quality level has been achieved, the vehicle is handed over to the responsibility of the production department.