Method of operating a compression ignition engine and compression ignition engine

摘要

Method for operating a compression ignition engine (2), which has at least one cylinder (5) and for each cylinder a fuel injection nozzle (7) designed to inject fuel into the cylinder, the method comprising the steps of: a) determining a desired position ( SOC) a start of the combustion of injected fuel by a main injection of fuel into the cylinder (5) in one work cycle thereof in relation to the position of a piston in the cylinder based on existing operating parameters of the engine, b) determining a position (SOI), in which is to request a start of a main injection of fuel into the cylinder with respect to the position of the piston in the cylinder (5), based on existing engine operating parameters and the desired position determined for the start of combustion. c) determining a position (EOI ) in which the main injection of fuel into the cylinder (5) is related the position of the piston in the cylinder is to be terminated based on existing operating parameters of the engine, d) determining whether there is a need to inject fuel in the form of a pre-injection at a time before the main injection for a combustion of the fuel injected before the combustion of the main injection fuel pre-injected into the cylinder to reduce noise generated at the start of combustion of the fuel injected in accordance with the main injection, and e) controlling the fuel injection nozzle for the cylinder for injecting fuel in accordance with a pre-injection if it was determined in step d) that the need exists , characterized in that step d) by using the results obtained by steps a) to c) to calculate a value of the difference in the positions of the start of the combustion and the start of the injection divided by the difference of the end of the Injection and start of injection for the main injection and taking this value into account as a measure of the need for a pre-injection, comparing the value with a predetermined value of this quotient ((SOC-SOI) / (EOI-SOI)) for the existing operating parameters of the engine and Determine that the need exists when the value is greater than the specified value to be executed.