Euro 3 and Euro4- Role of Doesel Fuel Injection Systems

The Euro 3 emission norms can be achieved by the well-known 1 st generation Common Rail Systems, Unit Injector Systems and electronically controlled distributor pumps (VP37 and VP44). The Euro 4 and beyond emission legislation is a challeging goal for diesel engine manufacturers. Lowest emissions with highest engine performance, namely high specific power output, petrol like noise levels, benchmarking low fuel consumption and attractive costs are the targets for development activities of the future engines. Key for the success will be a sophisticated fuel injection system which supports all the above mentioned targets. Therefore, BOSCH did launch a fundamntal project defining the requirements for future injection systems with regard to mixture preparation, maximum injection systems a comprehensive engine investigation was accomplished to optimise the system configuration to meet the above targets of diesel engines. Applying the criteria of performance, manufactiring robustness, lifetime durability and costs, the variety has been reduced to a piezo actiated common rial injection system for passenger cars and a hydraulically amplified common rial system which works with hydraulically amplifird injectors. These two concepts are describe in detail in this paper.