Method for driving solenoid-actuated fuel injectors of internal combustion engines
AssigneeGM Global Technology Operations LLC
InventorPaolo Casasso
Life of this patent
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Abstract
An accurate control of a solenoid-operated fuel injector in a Diesel or gasoline engine specifies that a pull-in voltage (Vpull-in) higher than the generally available battery voltage (Vbatt) is applied to the injector, and that the injection is ended as quickly as possible, in order that the fuel injection closely follows the solenoid current profile. When the initial pull-in voltage is lower than the expected nominal value, a deviation of the injected fuel quantity appears with respect to the nominal quantity. This inconvenience is overcome by monitoring the actual value of a selected parameter, such as the actual value of the initial pull-in voltage (Vpull-in), and the injection start time (te) and the solenoid energizing time (ET) are correspondingly modified.
Claims19
A method for driving a solenoid actuated fuel injector of an internal combustion engine for causing a fuel injection to occur, a nominal start time (te) for an injection and a nominal energizing time (ET) for an injector are predetermined as a function of prefixed parameters, and a voltage (V) having an initial predetermined nominal value (Vpull-in) is applied to said solenoid actuated fuel injector at the nominal start time (te) to cause in the solenoid actuated fuel injector a flow of an energizing current (I) which increases from zero to a predetermined peak value (Ipull-in), the method comprising the steps of:
- monitoring an actual value of at least one selected parameter that is related to a time period needed for a solenoid current (I) to pass from zero to a peak value (Ipull-in);
- and
- when the actual value is lower than a corresponding nominal value for the selected parameter, anticipating an injection start time with respect to the nominal start time (te) by an amount of time that is determined based on functional relationships between the selected parameter and the injection start time, which functional relationships are obtained and mapped in memory beforehand, so as to at least partially compensate deviations of the actual value of said at least one selected parameter with respect to a predetermined nominal value.
A method for driving a solenoid actuated fuel injector of an internal combustion engine for causing a fuel injection to occur, a nominal start time (te) for an injection and a nominal energizing time (ET) for an injector are predetermined as a function of prefixed parameters, and a voltage (V) having an initial predetermined nominal value (Vpull-in) is applied to said solenoid actuated fuel injector at the nominal start time (te) to cause in the solenoid actuated fuel injector a flow of an energizing current (I) which increases from zero to a predetermined peak value (Ipull-in), the method comprising the steps of:
- monitoring an actual value of at least one selected parameter that is related to a time period needed for a solenoid current (I) to pass from zero to a peak value (Ipull-in), wherein said at least one selected parameter is an actual duration of the time period needed for the solenoid current (I) to pass from zero to said predetermined peak value (Ipull-in);
- and
- modifying the nominal start time (te) and the nominal energizing time (ET) as a function of the actual value of said at least one selected parameter, so as to at least partially compensate deviations of the actual value of said at least one selected parameter with respect to a predetermined nominal value.
A method for driving a solenoid actuated fuel injector of an internal combustion engine for causing a fuel injection to occur, a nominal start time (te) for an injection and a nominal energizing time (ET) for an injector are predetermined as a function of prefixed parameters, and a voltage (V) having an initial predetermined nominal value (Vpull-in) is applied to said solenoid actuated fuel injector at the nominal start time (te) to cause in the solenoid actuated fuel injector a flow of an energizing current (I) which increases from zero to a predetermined peak value (Ipull-in), the method comprising the steps of:
- monitoring an actual value of at least one selected parameter that is related to a time period needed for a solenoid current (I) to pass from zero to a peak value (Ipull-in);
- modifying the nominal start time (te) and the nominal energizing time (ET) as a function of the actual value of said at least one selected parameter, so as to at least partially compensate deviations of the actual value of said at least one selected parameter with respect to a predetermined nominal value;
- monitoring a time distance between two successive fuel injections by the same injector;
- and
- merging said two successive fuel injections in one single injection when said time distance becomes smaller than a predetermined minimum threshold value.
A method for driving a solenoid actuated fuel injector of an internal combustion engine for causing a fuel injection to occur, the method comprising the steps of:
- applying a pull-in voltage that is higher than a battery voltage to the solenoid actuated fuel injector;
- determining an actual value of the pull-in voltage applied to the solenoid actuated fuel injector;
- comparing the actual value with an initial predetermined nominal value (Vpull-in);
- when the actual value is lower than the initial predetermined nominal value,
- determining a reduction in the actual value with respect to the initial predetermined value, wherein the reduction is functionally related to a difference between the actual value and the initial predetermined nominal value, and
- determining, based on the reduction, one or more amounts by which one or more parameters relating to the fuel injection are to be modified from one or more nominal values, wherein the one or more parameters are selected from a group consisting of an injection start time, a crank angle, and an energizing time, and wherein the one or more nominal values are selected from a group consisting of a nominal start time, a nominal crank angle, and a nominal energizing time;
- and
- driving an injection solenoid of the solenoid activated fuel injector in accordance with the one or more amounts by which the one ore more parameters are to be modified.
A method for driving a solenoid actuated fuel injector of an internal combustion engine for causing a fuel injection to occur, the method comprising the steps of:
- determining a nominal start time (te) and a nominal energizing time (ET) for driving the solenoid actuated fuel injector;
- applying a voltage (V) having a predetermined nominal value (Vpull-in) to the solenoid actuated fuel injector at the nominal start time (te) to cause a flow of an energizing current (I) in the solenoid actuated fuel injector, wherein the energizing current increases from zero toward a predetermined peak value (Ipull-in);
- monitoring an actual value of at least one selected parameter that is related to a time period needed for the energizing current to increase from zero to the peak value;
- and
- modifying driving of the solenoid actuated fuel injector, based on functional relationships between the at least one selected parameter and the injection start time that are mapped in a memory, by performing one or more modifications selected from a group consisting of anticipating the nominal start time (te) and increasing the nominal energizing time (ET) as a function of the actual value of the at least one selected parameter, so as to at least partially compensate deviations of the actual value of the at least one selected parameter with respect to a predetermined nominal value.
Dependencies are inferred from the claim text.