Advanced fuel metering gasoline - requirements and Bosch system solutions

This paper presents Bosch's advanced fuel control strategies to satisfy future requirements of improved fuel economy and reduced emissions without compromising drivability and comfort. A system solution that integrates the hardware improvements with dedicated control algorithms can further exploit the benefits of Port-Fuel Injection (PFI) and Direction Injection (DI) technologies. In addition to the increased fuel system pressure, innovative manufacturing techniques can allow flexible design for injector holes, which leads to improved spray targeting and formation. In order to ensure accurate and reliable fuel delivery in small quantity, Controlled Valve Operation (CVO) is proposed to enable closed-loop control of the injector needle motion. The CVO technology has demonstrated its potentials to not only enable multiple injection strategy during start, but also ensure consistent behaviors of an injector over its entire use life.