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Three-cylinder Engine without balancer shaft is a recent trend towards development of lightweight and fuel-efficient powertrain for passenger car. In addition, customer's expectation of superior NVH inside vehicle cabin is increasing day by day. Engine mounts address majority of the NVH issues related to transfer of vibration from engine to passenger cabin. Idle vibration isolation for a three-cylinder engine is a challenging task due to possibility of overlapping of Powertrain's rigid body modes with engine's firing frequency. This Overlapping of rigid body can be avoided either by modifying mount characteristic or by changing the position of mounts based on multi-body-dynamics (MBD) simulation. This paper explains about two types of engine mounting system for a front-wheel drive transversely mounted three-cylinder engine. The base vehicle was having three-point mounting system i.e. all three engine mounts were pre-loaded.

Structure borne noise is the major source of noise inside the vehicle compartment. Recently the quietness of the occupant cabin has become an important dimension to the quality of product. OEMs are finding it challenging to meet the customer expectations for “Powerful yet quiet” attribute. Several focused studies have been made to reduce the under hood component noise in automobiles. This paper summarizes the optimization of vibro-accoustic sensitivity (VAS) of the engine mounts in passenger car engine. The contribution of each engine mount on the structure-borne noise transfer inside the cabin is studied by conventional FRF and normal mode analysis using Nastran, along with physical testing validation. This paper emphasizes to reduce the structure borne noise with the focus on weight reduction of the body side engine mount.

Hydromount plays an important role in isolating vibration during idling. To meet ideal NVH criteria, a properly tuned Hydromount is required otherwise there will be abnormal noise due to cavitation effect. Cavitation noise is such a noise which is very difficult to identify in initial vehicle development stage. The effects of cavitation in the Hydromount become increasingly important for noise and performance goals. Cavitation is the formation and collapse of vapor bubbles in a working fluid when local static pressure falls below the vapor pressure of the working fluid. Technique to detect cavitation in Hydromount is presented in this paper. The countermeasure technique concentrates on increasing the fluid flow rate betweens fluid chambers. The results for different design countermeasure performance have been measured and the performance is compared in the vehicle. The results of vehicle level tests show the same trends as bench test results.