Search Results

Common rail direct injection technologies have enabled the development of very high power and torque for a given capacity of the engine. These high performance engines have very high brake mean effective pressures and peak firing pressures. These high pressures increase the blow-by gas flow in cylinder crankcase. Vehicle brake assist systems as well as some actuators on engine need the vacuum. The vacuum is generated by the vacuum pump driven by the engine cam shaft or separately as accessory drive. The air pulled for creating the vacuum gets mixed with the lubricating oil. This air mixture with the lubrication oil gets circulated in the blow by circuit. Collectively, blow-by gases and the vacuum pump oil with air carry substantial engine oil particles. These oil particles need to be separated before connecting to the air intake circuit to reduce oil consumption and to reduce exhaust emissions. Generally cyclone type oil mist separation systems are used on the automobile engines.

The modern trend of engine downsizing for CO₂ reduction coupled with stringent emission norms compel the engine air inlet system to outperform the conventional designs. Modern turbo diesel engine air inlet system handles higher & higher air flow, boost pressure and temperature. Air inlet system ducting designs have become complex due to oil particles (received through PCV system), engine movement and isolation for NVH. Air inlet ducting failures; like oil mist leakage through joints and seepage through hose wall cause high engine oil consumption and most predominantly environment damage. Also to some extent boost leakage in certain operating conditions. These failures reduce the reliability and performance of engine in certain conditions. This paper discusses design and development of cost-effective non-permeable and leak-proof hose-piping system for turbocharged diesel engine where PCV system was connected to air inlet system.