Shibata, H., Mizobuchi, T., Iwamuro, M., Koda, A. et al., "New Spray Concept Development for Dual Injection System," SAE Technical Paper 2017-01-0835, 2017, doi:10.4271/2017-01-0835.
Gasoline direct injection (GDI) systems are a main development focus for global environment issues and energy security. At the same time, it is also important to challenge further development of Multi point injection (MPI) systems for a simple and robust combustion system responding to global fuels ,required for the growing automotive markets in emerging countries, especially in the A, B vehicle segments. This paper focuses on reducing wall wetting in cold conditions and maximizing mixture cooling by fuel vaporization (preventing knocking) in high load conditions as key development points of MPI systems. We propose a dual MPI system enhancing direct flow of spray into the combustion chamber to gain part of the benefit of GDI in addition to the homogeneity advantage of an MPI system. This dual MPI system requires finer atomization with at the same time robustness against intake airflow. Our unique atomization technology and spray pattern optimization improve both atomization and robustness against intake airflow realizing an open valve injection benefits.