Patent ID: 9127632
Filing Date: 2015-09-08
Classification: F02D,F02M,H02N

Abstract:
1. A method for detecting faulty components of a piezo-injector of a fuel injection system of an internal combustion engine, the piezo-injector having a piezo-electric actuator and configured to drive a nozzle needle, and being configured for operation in a partial-stroke mode and a full-stroke mode, the method comprising: achieving a defined operating point of the internal combustion engine, measuring a first time after which the nozzle needle impacts against a stop during an opening of the nozzle needle, and a second time after which the nozzle needle impacts against a needle seat during a closing of the nozzle needle, comparing the first and second measured times with predetermined time values, calculating one or more parameters of the fuel injection system using multiple different calculation models, and storing the calculated parameters from the multiple calculation models, comparing the calculated parameters from the multiple calculation models with predetermined parameter values, comparing the calculated parameters from the multiple calculation models with one another; and determine if a fault condition is present based on the comparison of the first and second measured times with predetermined values, the comparison of the calculated parameters from the multiple calculation models with predetermined parameter values and the comparison of the calculated parameters from the multiple calculation models with one another.