| A recent development from ArvinMeritor engineering teams – some of the best in the business, according to Bob Marty, the genial American who steers ArvinMeritor’s Light Vehicle Systems (LVS) business group from its headquarters in Sully-sur-Loire in central France – is the Highly Integrated Plastic (HIP) door module, an alternative to the traditional steel door carrier frame.
“OEMs rely on suppliers to make complete systems and we produce carrier modules, trim modules and structural modules,” says Mark Lawrie, window regulators and modules chief engineer. “A move away from steel to plastic carriers started in 1990, and our current version uses plastic for the plates rather than steel. However, for our fourth-generation module, our aim is to reduce both cost and weight by fully integrating a number of electrical and mechanical components into the plastic mould.
“On the traditional unit, the window regulator, latch, radio speaker, motor and electronics are mounted to a large steel carrier plat using bolts and clips. Through plastics moulding technology, we’ve designed components such as rivets, fittings and guide rails directly into the plastic module.
“This gives improved product quality and reduces the complexity of assembly – and we have achieved a 25 per cent saving in weight. We’re about to start demonstrating the concept to car manufacturers and I’d think that in three years from now, when the unit is likely to be adopted, we will be in a position to offer a cost saving in the order of 25 to 30 per cent.
“With the rising cost of steel and pressures on overheads set to increase still further, this is the kind of language the industry likes to hear. We’re predicting this development will be a significant success,” says Lawrie.
Because the plastic composite is more absorbent than steel, the HIP is also expected to make a contribution to noise reduction. Lawrie admits, though, that making the composite sufficiently robust to resist stretching over long-term use is a complex issue, and says crash safety is another factor to be embraced in the final design.
Another development, the Glass Motion Module (GMM) represents further progress in research and development efforts that represent five per cent of the company’s total sales revenue. To be offered to volume manufacturers, the complete frame and glass system for doors has the potential to save €20 per car as well as improving overall quality.
“A manufacturer like Renault has to make a big investment in tooling to accommodate window requirements when it makes a wide range of passenger car models based on a single platform,” says Lawrie. “We will be in a position to help in future by reducing the need for modifications to the frame area and glass. GMM optimises all we know about window motion and door assembly.”
A further example of cost and weight reduction will come with a new power tailgate assembly under development at ArvinMeritor’s advanced engineering and innovation department. “We tested every unit on the market and found the one in the Opel Vectra to be the most rugged and the installation in Honda’s Accord Tourer the most sophisticated.
“Then we set out to offer a competitive alternative system that’s lighter and more compact. By having the motor located in the tailgate rather than in the car bodywork, it is also less complicated, and we can be particularly competitive on cost because we manufacture all the components,” says operation director Dominique Benoit.
Patent protection has already been applied to a ‘smart lever’ system that has reduced the force needed to release the tailgate from 800 Newtons to less than 100 Newtons – a development that allows the use of a standard, less costly window motor.
“This system is more about evolution than revolution, but we believe it will create a significant new business area for us. Power tailgates are prominent in North America and are fast gaining popularity in Europe . We should be able to offer this feature for around €500…it is a good way for us to increase our business,” says Benoit.
Adds Marty: “There is no doubt that component suppliers will have greater influence with OEMs in time. Modules will be a major factor in new manufacturing plants, where they are minimising inventories, minimising costs and minimising defects because systems are tested before they even reach the assembly lines.” |
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