Tokyo show: Mazda R&D focuses on weight, NVH

ALTHOUGH Mazda’s new-generation SkyActiv-Vehicle Architecture is yet to debut in production form, the Japanese car-maker is already looking ahead for ways to further lower weight as well as noise, vibration and harshness (NVH) levels.

Speaking to Australian journalists at the Tokyo motor show last week, Mazda Motor Corporation general manager of vehicle development Hiroyuki Matsumoto said the biggest hurdle to overcome in future product development is heaviness.

“The biggest challenge for me is light weight,” he said.

“Mazda made an announcement that we are going to improve real-world fuel economy by 50 per cent by 2030 and 90 per cent by 2050, so to achieve these goals, light weight is an important element.”

Mr Matsumoto revealed that Mazda is taking a holistic approach to the problem rather than simply substituting components with lighter-weight parts.

“From the lightweight approach, we will substitute materials such as aluminium and CFRP (carbon-fibre reinforced plastic), but materials alone are not enough to achieve light weight,” he said.

“If we assume the current vehicle architecture or structure to remain, if we change materials only, then the effect of light weight is not so much.

“So when we change materials, we will also integrate various parts, so one part will serve various functions, we call this approach ‘multi-function approach’.

“Our approach is multi-material and multi-function, and we’re going to simplify parts with these technologies combined. We think we can achieve a big weight reduction.”

Although expensive to work with, Mr Matsumoto said new production methods were being developed to speed up the process, as well as strengthening the material further.

“We think CFRP is a very efficient material,” he said. “By controlling direction of fibre, we can make it very rigid.

“CFRP is expensive because it takes much longer times to produce it, so together with suppliers we are developing technologies for the manufacturing process so that we can quicken the time of production.

“So until that technology becomes available, we are going to utilise CFRP in the most effective areas in a limited manner.”

A reduction in weight can come at the expense of increased NVH levels – an area in which Mazda vehicles have previously been criticised – but Mr Matsumoto said new manufacturing techniques are being developed to work around the problem.

“To be sure, yes, NVH is strongly related to mass weight,” he said. “There is the principle of mass that means insulation is also proportional to weight or mass.

“So we want to break away from that philosophy of mass, we want to develop technology to break down that.

“One of the approach we are thinking is to control air.

“So sound comes in then out … sound is dampened. The bigger the mass is then sound levels get lower.

“But if we go along this approach, the car gets heavier.

“So we’ll have another layer between the two, air is filled in between the two layers. Then noise can be damped, not transferred.

“So we tried to create these layers so weight is light and it can absorb sound.”

Mr Matsumoto said this technology is being developed for application across the entire passenger chamber and that less mass would not mean less protection in a crash.

“All the best materials should be adapted to the best position, these areas should absorb energy,” he said.

“With the current technologies levels, iron, steel and aluminium are the best materials – and shape is important.”

Mr Matsumoto indicated certain structural elements would be manufactured in a cross shape, for example, instead of the traditional rectangle beam for improved crash-absorption properties while maintaining less weight.

While some of these new technologies will likely skip SkyActiv-Vehicle Architecture for the platform’s offspring close to a decade down the line, Mazda will likely roll out at least some improvements before then.

The SkyActiv-Vehicle Architecture will debut in 2019 with the release of the new-generation Mazda3 before proliferating across the brand’s entire passenger car and SUV line-up.