F2010A164
Development toward "Diesel Revolution" using Ultra High pressure CRS with closed-loop control system for Heavy Duty Engine
Fuel-efficient and high-power diesel engines have been widely used in various kinds of vehicles from passenger cars to off-road vehicles to contribute helping to reduce global warming. However, emissions and fuel consumption regulations are increasingly being tightened. Among such harsh regulatory environments, it becomes increasingly difficult to meet the future emission regulations and CO2 emission regulations at reasonable costs without reducing its quality such as output characteristics and drivability. In particular, off-highway heavy-duty vehicles require diesel engines without failure and are eager to look for a new technology to overcome these issues. As means to reduce emissions from diesel engines, various kinds of technologies, such as air-path improvement by high pressure turbo-charging and high EGR rate, aftertreatment systems including DPF and SCR are actively being developed. These technologies, however, still have many problems of fuel economy and cost. Accordingly, injection systems must be highly responsible for keeping a good balance between the new technology development and cost, and improving performance simultaneously. One of the performance improvement approaches by injection system is an ultra-high injection pressure. The increasingly stringent regulations accelerated the increase in injection pressure, 1200 barą1800 bar ą 2000 bar. In order to achieve emission performance equivalent to small cars in heavy duty engines to meet future Euro6 and Final Tier4, further improvement will be essential. DENSO is currently developing CRS capable of injecting 3000 bar. The system with 3000 bar contributes to a drastic improvement of spray, leading to a significant improvement in combustion efficiency. On the other hand, in order to make full use of CRS potential realized by ultra-high pressure, an increase in injection accuracy performance is essential, in particular, multiple injection accuracy. DENSO developed an injector having a built-in pressure sensor and established the technology of i-ART (intelligent accuracy refinement technology) system that autonomously compensates injection quantity and timing. The system offered the prospect of mass production of the world's first complete closed-loop control of diesel injection system. As heavy duty vehicles are subject to long service distance and period and severe environment of use, it is a big issue to assure performance throughout the vehicle lifetime. Using i-ART allows multiple injection quantity and timing to be assured accurately throughout the lifetime to achieve a substantial improvement in emissions and fuel consumption performance. In addition, i-ART　 is a revolutionary solution from the viewpoints of calibration man-hour reduction and OBD2 conformity. Accelerating diesel engine performance improvements by these advanced CRSs, we aim to contribute to Diesel Revolution where diesel engines gain excellent competitiveness among various powertrain units.
This abstract is supplemented by a PDF, which can be viewed here.
Session: IC Engines, Goals and Development