Characteristics of Control Piston Motion and Pressure Inside of a Common Rail Diesel Injector

[EN] In this paper the experimental setup of a commercial third generation common rail solenoid injector with advanced measurement is discussed. The motion of the control piston is measured while performing injection rate investigations using a purpose-built injection rate analyzer of the Bosch type. At the same time fuel pressure in the feed line of the nozzle is gauged and contrasted to fuel pressure before the inlet connector. In contrast to the steady rise observed in a similar study, the motion of the control piston in this case is characterized by a changing gradient in the upward movement. The magnitude of the negative displacement of the upper part of the control piston due to the fuel pressure in the control volume corresponds to simulation results of the elastic deformation. Pressure before the inlet connector and pressure in the feed line exhibit a similar course with a difference in magnitude that is rising with higher rail pressures. Precisely with the end of injection the pressure in the feed line surpasses the pressure before the inlet connector for a short moment. The measurement results of control piston motion and pressure inside the injector are of particular interest because these parameters are to serve as indicators for changes in the injection rate caused by phenomena like wear and coking amongst others.The authors thank the German Research Foundation DFG for the funding of the project (reference number WA 2468/4-1) in which the here presented results originated. Furthermore, the authors thank Martin Niedermeier for the development the injector and Mario Meinhardt for the development of the data acquisition.Schuckert, S.; Wachtmeister, G. (2017). Characteristics of Control Piston Motion and Pressure Inside of a Common Rail Diesel Injector. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 569-577. https://doi.org/10.4995/ILASS2017.2017.6454OCS56957