| 摘要 |
A method is disclosed to determine the opening degree of injectors in cylinders in a combustion engine with at least three cylinders, wherein the injectors are connected to a fuel accumulator in a common rail fuel injection system, the fuel supply to the fuel accumulator is interrupted, and subsequently a test injection of fuel is carried out into at least two and at most all except one cylinder at a time, in different combinations, at such a time that the injection does not cause any combustion in the cylinders. The pressure decreases caused in connection with the different test injections are measured, and the pressure decrease which is attributable to at least one specific injector is calculated based thereupon, which is used in the determination of the injector's opening degree. |
| 主权项 |
1. Method to determine the opening degree of injectors in cylinders in a combustion engine with at least three cylinders, wherein said injectors are connected to a fuel accumulator in a common rail fuel injection system and wherein the method starts when the fuel accumulator is pressurized, wherein the method comprises:
a) interrupting the fuel supply to the fuel accumulator; b) controlling at least two, and at most all except one of the injectors, to simultaneously open at a specified time and to carry out a test injection of fuel into the associated cylinders, wherein the test injection is carried out at such point in time that the injection does not cause any combustion in such cylinders; c) measuring the pressure decrease in the fuel in the fuel accumulator resulting from the test injection; d) repeating operations b) and c) for a number of divergent combinations of injectors participating in the test injection, so that a subsequent operation e) may be carried out; e) calculating, based on measured pressure decreases during the test injections, the pressure decrease which is attributable to at least one specific injector; and f) comparing the pressure decrease calculated for said at least one injector with a pressure decrease expected, at a certain opening degree of the injector for the given fuel pressure in the fuel accumulator and a certain opening time of the injector, and based on this comparison to determine an injector's opening degree. |
