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Up-To-Date Noise Reduction, E.G., on the New Db 190d
Sector:
Language:
German
Abstract
In Autumn 1983, Daimler-Benz launched the world's first
fully-noise-encapsulated Diesel car, in the form of the 190D.
During its development, priority was given not only to compliance
with the stricter legal noise limits which are to be implemented ~
the 190D would manage that even without any special features ~ but
also to the desire to make the car noticeably quieter than any of
its rivals, both inside and out, and at any engine speed.
The result is a car with body-mounted engine-compartment
encapsulation which completely seals off the engine/gearbox
assembly from outside, apart from a few air intake and outlet
apertures. This cuts down noise emission by about 4-5 dB(A):
following the procedures laid down in EEC Directive 81/334, noise
levels of 75/73/71 dB(A) were recorded, depending on the type of
gearbox fitted. Noise emission at tickover is under 50 dB(A) in all
cases. The typical knocking noise of a diesel is now scarcely
discernible. Particular attention was also paid to the increased
weight, higher engine-compartment temperatures, and the cost. The
resultant compromise can be seen ~ or rather, heard ~ to be a
thoroughly respectable one