Innovative Approach to Address BS VI Challenges of NVH Refinement and Total Cost of Ownership of Small Commercial Vehicles with Naturally Aspirated Two Cylinder Diesel Engines 2021-26-0284
Small commercial vehicles (SCVs) are the drivers of a major part of India’s indirect economy, providing the most efficient means of transport. With the introduction of BS-VI norms, some major overhauls have been done to the SCV models to meet BS VI norms in challenging timeline for early market entry. This forced to automotive designers towards challenge of cost competitiveness as well as refinement level to survive in this competitive market.
This paper explains the systematic approach used to overcome challenges of higher tactile vibrations, higher in-cab noise because of BS VI requirement in 2 cycle engine required for small commercial vehicle. The solutions were need to be worked out without compromising the other performance attributes like total cost of ownership, fuel economy, ease of servicing and cost effectiveness.
With universal truth that for two cylinder engines with 360 degree phase crankshaft configuration, naturally aspirated common rail diesel engine, there will be more noise and vibration if a Mass Balancer Unit [MBU] is not given. This is because of higher unbalanced forces and torques, resulting in higher tactile vibrations as well as higher in-cab noise. Generic design solutions like mass balancer unit for higher unbalance forces, major design changes were not possible to implement because of cost element and time line.
This challenge was addressed through appropriate balancing strategy of crankshaft assembly with suitable engine mount configuration to decouple power train rigid modes and tuned mass damper at engine mounting arm to take care of contribution of mounting arm resonance in higher in cab noise.
It was observed that with appropriate engine crankshaft balancing, suitable engine mounts with correct mount stiffnesses and locations along linear mas damper at front engine side mounting bracket, driver seat rail (DSR) vibration reduced by more than >75% in vehicle IDLE condition reduction of overall in-cab noise by 3 dB(A). Solutions resulted in superior NVH performance ensuring the leadership position of TML for NVH refinement with simpler cost effective designs
Citation: Yeola, Y., Kalsule, D., Sawangikar, P., Naidu, S. et al., "Innovative Approach to Address BS VI Challenges of NVH Refinement and Total Cost of Ownership of Small Commercial Vehicles with Naturally Aspirated Two Cylinder Diesel Engines," SAE Technical Paper 2021-26-0284, 2021, https://doi.org/10.4271/2021-26-0284. Download Citation
