Wheels: -29%. Differential: -14%. Diesel pump housing: -18%. Nuts: 6 g each. At Hannover Messe, the Lightweight Forging Initiative, a primarily German consortium of forging companies and steel producers, has been trumpeting an impressive list of weight-saving measures for automotive parts which could result in a total reduction of 99 kg (PDF).
Two years ago, the Lightweight Forging Initiative dismantled a passenger car and announced that 42 kg could be saved. This time, it did the same with a van, disassembling it, listing and analyzing all parts and, through workshops with experts, formulating lightweight design ideas.
Lighter Powertrain and Chassis
Given the focus of the consortium members, it was decided to focus on the chassis and powertrain rather than on the vehicle body or the electronics. At 845 kg, these elements constitute 36% of the vehicle’s weight, already a hefty bit to chew on.
And chew they did, as the team of engineers and researchers developed lightweight design proposals for each part, with novel solutions at almost every turn:
- Removal of unnecessary material and use of lighter forged parts for the diesel pump housing and cover;
- for the gearwheel of the output shaft, producing holes on pitch circles and creating a thinner fixed member with a wave profile;
- a new design and use of a bainitic steel for nuts
Even the lead researchers were surprised by the weight savings possible in very small parts, as they explained to DirectIndustry e-magazine during Hannover Messe.
It was surprising to realize how much screws and nuts could be improved. For fasteners, with the right design and an appropriate steel, we could gain approximately 700 g for an entire vehicle.
A New Research Network
Once finalized, this second phase will mark a turning point for the Lightweight Forging Initiative. Phase I demonstrated savings of 42 kg in a passenger car. Phase II now shows that 99 kg can be saved in a commercial vehicle. The next step is sharing these innovating ideas throughout the industry. To this end, a Lightweight Forging Research Network has been established, uniting 64 companies, 4 research associations, 10 research institutes and 2 universities.
Indeed, the automotive industry is expected to react quickly. Weight reduction is one of the most obvious ways to comply with ever more stringent CO2 regulations. In Europe, for example, the 2020 target for light commercial vehicles is a reduction of 147 grams of CO2 per kilometer, 19% less than the 2012 average.