Electronic future
Page 19
If you've noticed an error in this article please click here to report it so we can fix it.
MAN's vehicles of the Nineties will have computer-controlled mechanical gearboxes coupled to diesel engines of similar design to those of today, but equipped with electronic control in various forms.
"There will be no stopping the use of electronics in commercials," forecast MAN technical director, Dr Klaus Schubert last week.
Dr Schubert told engineers in Solihull that "there is no substitute for the diesel engine as the most economical power unit.
"In the last 10 years, the diesel has reached a high degree of development. Further fuel economy improving steps will be small ones," he added.
Dr Schubert said MAN is looking for fuel economy improvements from its diesel engines by reducing power losses from auxiliaries. He gave two examples of current development work along these lines.
"By optimising cooling fan design, with a typical viscous fan engaged 45 per cent of the time, a fuel consumption saving of 0.5 lit/100km is possible," he said.
The "optimisation" would involve increasing the distance between the fan and the engine, a special fan blade con struction and a special fan cowl, all designed to improve the air flow around the engine.
This would reduce the power absorbed by the fan from 5.14 to 3.45kW (6.9 to 4.6hp) and give a bonus of lower noise levels. "Our future trucks will have these fans," he said.
His second example of MAN's current development work on reducing auxiliary power losses concerned several means of disconnecting compressors. "An electro-magnetic clutch is one way," said Dr Schubert. "This is expensive at the moment but it will come in time."
At present MAN's powersteering pump is driven through the compressor, so the positions of these two components will have to be transposed before the compressor can be disconnected.
On the subject of efficiency of transmissions and axles, Dr Schubert said that he thought the possibilities for improvements were now "almost ex hausted."