The authors reclaime to be the first to report about a micromachined mass flow sensor directly integrated in a Common Rail (CR) injection nozzle between the double guidance and the needle seat. This enables to study time-resolved and in detail important processes as pressure waves occurring during and after the injection at a place, where the injection rate is strongly influenced. Therefore, ,on-board' mass flow sensors, enabling a closed-loop control of every magnetic or piezoelectric driven valve, could help to soften the tolerances of the mechanical parts in the injection system and hence, could substantially lower the production costs of the latter. The thermal measurement principle is chosen, because it enables a very precise and fast detection of gaseous and liquid mass flows. Additionally, the velocity field in the nozzle is only slightly influenced by the integration of the sensor in the nozzle body due to the negligible height of the sensitive layer. Also the outer geometry of the nozzle is not affected by the integration of the sensor, to guarantee that the cylinder head of the combustion chamber can keep its original design as far as possible. For hot film anemometers, a high temperature as well as a high pressure stable glass-ceramic substrate can be used, fabricated in a low cost batch process. The technology, to fabricate the sensor as well as its electrical characterisation up to 300 Cel on the ceramic substrate is presented. Finally, the first flow measurements at 600 bar, carried out at a high pressure hydraulic test bench, are discussed.
A mass flow sensor for fuel injection quantity measurements in DI-systems
Ein Kraftstoffmengenmeßgerät zur Erfassung der Einspritzmenge von Direkteinspritzern
2001
17 Seiten, 11 Bilder, 25 Quellen
Conference paper
English
A Mass Flow Sensor for Fuel Injection Quantity Measurements in DI-Systems
British Library Conference Proceedings | 2001
|Study of a Sensor for Fuel Injection Quantity
SAE Technical Papers | 1997
|Study of a sensor for fuel injection quantity
Automotive engineering | 1997
|On board injection rate measurements at DI-Systems with a micromachined mass flow sensor
Automotive engineering | 2001
|On Board Injection Rate Measurements at DI-Systems With a Micromachined Mass Flow Sensor
SAE Technical Papers | 2001
|