Procedure to Assess the Vibroacoustic Quality of a Diesel Engine in Assembly Workshop 2009-01-2166
Customers demand a higher quality level of the automobile vehicles. These demands include noise, vibration and harshness (NVH) quality as an important item.
The combustion engines are the main source of NVH on the vehicle, particularly in case of diesel engines. Manufacturers have focused their design efforts on reducing the noise and vibration levels transmitted to passengers and car drivers in order to improve the quality and comfort from a customer point of view. However the designer's effort to reduce these emissions of noise and vibration could be lessened because of the engine assembly process variation.
In the present work, a procedure to assess these variations in order to maintain NVH performances within the limits of design and to achieve the quality level expected by the customer is proposed.
To achieve it, the engine vibration level has been measured through three sensors allocated at strategic points. Some objective criteria based on the vibration level at certain frequencies have been established to assessing the engine quality level as a final step of the engine assembly process.