Method and device for controlling the fuel quantity injected into an internal combustion engine, in particular a diesel engine equipped with a common rail injection system

A control device (3) for controlling the fuel quantity injected into an internal combustion engine comprising a number of injectors (4), each for injecting a given fuel quantity into a respective cylinder (5);

• said control device (3) being characterized by comprising:
• energization means (14) for determining a nominal energization time (EN) of said injector (4) as a function of injection pressure (PRAIL) and the nominal fuel quantity (Qi) required by the user;
• correcting means (15, 19) for determining a correction energization time (ET) as a function of injection pressure (PRAIL) and the cylinder (5) involved in said injection;
• control means (16) for determining, in the event the required nominal fuel quantity (Qi) is below a predetermined threshold (SQ), a corrected energization time (EC) by correcting said nominal energization time (EN) as a function of said correction energization time (ET);
• and
• drive means (16) for exciting said injector (4) for a time equal to said corrected energization time (EC);
• said correcting means (15, 19) comprising:
• control means (140) for performing, in the presence of a predetermined series of operating conditions (100) of said engine (1), a succession of energizations of an injector (4) with gradually increasing energization times (ET);
• detecting means (150) for determining a quantity (Acc) related to the output torque of said engine (1) in response to said succession of energizations;
• and
• processing means (170, 180) for calculating said correction energization time (ET) as a function of said quantity (Acc) related to the output torque.