Method for operating a fuel injection system of an internal combustion engine

• US 9,121,360 B2
• Filed: 12/07/2009
• Issued: 09/01/2015
• Est. Priority Date: 12/11/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Richter, Uwe, Wilms, Rainer, Schumacher, Matthias, Kuempel, Joerg, Maess, Matthias
• Primary Examiner(s): Low, Lindsay
• Assistant Examiner(s): BAILEY, JOHN D
• Application Number:
  US13/139,206
• Publication Number:
  US 20110288748A1
• Time in Patent Office: 2,094 Days
• Field of Search: 137/51, 137/55, 137/246.12, 137/246.16, 137/246.17, 123/456, 123/205, 123/357, 123/364, 123/375, 123/379, 123/381, 123/387, 123/390, 123/406.47, 123/445, 123/446, 123/447, 123/457, 123/458, 123/464, 123/482, 123/488
• US Class Current: 1/1
• CPC Class Codes: F02D 2041/2027 Control of the current by pulse width modulation or duty cycle control
• CPC Class Codes: F02D 2041/2037 for preventing bouncing of the valve needle
• CPC Class Codes: F02D 2041/2055 with means for determining actual opening or closing time
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils
• CPC Class Codes: F02D 41/2464 Characteristics of actuators
• CPC Class Codes: F02D 41/345 Controlling injection timing F02D41/365 takes precedence
• CPC Class Codes: F02D 41/3845 by controlling the flow into the common rail, e.g. the amount of fuel pumped
• CPC Class Codes: F02D 41/401 Controlling injection timing F02D41/402 takes precedence

Abstract

In a fuel injection system of an internal combustion engine fuel is delivered into a fuel rail by a high-pressure pump. The quantity of the delivered fuel is influenced by a quantity control valve operated by an electromagnetic operating device. At least one parameter of a braking pulse of the electromagnetic actuating device depends on an efficiency of the electromagnetic actuating device and/or on a supply voltage of a voltage source and/or on a temperature, in particular of a component of the fuel injection system or of the internal combustion engine.

Claims

1. A method for operating a fuel injection system of an internal combustion engine, comprising:

ascertaining a pulse duty factor at which a quantity control valve one of just no longer opens and just barely opens;

delivering fuel by a high-pressure pump into a fuel rail; and

influencing a quantity of the delivered fuel by the quantity control valve operated by an electromagnetic operating device, at least one parameter of a braking pulse of the electromagnetic operating device depending on both an efficiency of the electromagnetic operating device and also at least one of (a) a voltage of a voltage source, (b) a temperature, and (c) a temperature of at least one component of at least one of (i) the fuel injection system and (ii) the internal combustion engine;

wherein at least one level of efficiency of the electromagnetic operating device is characterized as having one of a high level of efficiency and a low level of efficiency according to the ascertained pulse duty factor, and

wherein, responsive to the at least one level of efficiency being characterized as having the high level of efficiency, the braking pulse at least one of (a) occurs later, (b) has a shorter duration, and (c) is weaker, than in a case of an electromagnetic operating device having a lower level of efficiency, and

wherein, responsive to the at least one level of efficiency being characterized as having the low level of efficiency, the braking pulse at least one of (a) occurs earlier, (b) has a longer duration, and (c) is stronger, than in a case of an electromagnetic operating device having a higher level of efficiency.

2. The method according to claim 1, wherein a power supplied to the electromagnetic operating device is altered successively in an adaptation method from a starting value at a start time to a final value at a final time, wherein the final time is when the quantity control valve is one of no longer or just barely detected as being open or closed.

3. The method according to claim 1, wherein the at least one parameter of the braking pulse includes at least one of a start of the braking pulse, a duration of a pulse width modulation phase or a current-controlled phase of the braking pulse, a duration of a pick-up pulse before the first pulse width modulation phase, a pulse duty factor or a current level during a holding phase before the braking pulse, and a pulse duty factor or a current level at the end of a holding phase before the braking pulse.

4. The method according to claim 1, wherein an opening or closing of the quantity control valve is detected by monitoring a deviation of an actual pressure in the fuel rail from a setpoint pressure.

5. The method according to claim 1, wherein a shape of the braking pulse is defined by at least one of sequences of a plurality of pulse width modulation phases, pick-up pulse phases without pulse width modulation, current controlled phases, defined stage quenches, and Zener quenches.

6. The method according to claim 1, wherein an energized holding phase of the electromagnetic operating device begins during a delivery stroke and wherein the energized holding phase of the electromagnetic operating device is terminated after the end of the delivery stroke.

7. The method according to claim 1, wherein a holding phase is terminated at a defined pulse width modulation flank during triggering with pulse width modulation.

10. The method according to claim 7, wherein the defined pulse width modulation flank is a falling PWM flank.

11. The method of claim 1, wherein at least one of the voltage of the voltage source and the temperature of the at least one component of at least one of the fuel injection system and (b) the internal combustion engine affects the braking pulse according to an engine characteristics map.

12. The method of claim 2, wherein the final value or a variable based on the final value is used to characterize the efficiency of the electromagnetic operating device.

8. A non-transitory computer-readable storage medium, for at least one of (a) a control device and (b) a regulating device of a fuel injection system, with an executable program stored thereon, wherein the program is executed by a microprocessor to perform the following steps:

ascertaining a pulse duty factor at which a quantity control valve one of just no longer opens and just barely opens;

delivering fuel by a high-pressure pump into a fuel rail; and

influencing a quantity of the delivered fuel by the quantity control valve operated by an electromagnetic operating device, at least one parameter of a braking pulse of the electromagnetic operating device depending on both an efficiency of the electromagnetic operating device and also at least one of (a) a voltage of a voltage source, (b) a temperature, and (c) a temperature of at least one component of at least one of (i) the fuel injection system and (ii) the internal combustion engine;

wherein at least one level of efficiency of the electromagnetic operating device is characterized as having one of a high level of efficiency and a low level of efficiency according to the ascertained pulse duty factor, and

wherein, responsive to the at least one level of efficiency being characterized as having the high level of efficiency, the braking pulse at least one of (a) occurs later, (b) has a shorter duration, and (c) is weaker, than in a case of an electromagnetic operating device having a lower level of efficiency, and

wherein, responsive to the at least one level of efficiency being characterized as having the low level of efficiency, the braking pulse at least one of (a) occurs earlier, (b) has a longer duration, and (c) is stronger, than in a case of an electromagnetic operating device having a higher level of efficiency.

9. A device for at least one of controlling and regulating a fuel injection system, the device to perform, upon execution by a microprocessor, the following steps:

ascertaining a pulse duty factor at which a quantity control valve one of just no longer opens and just barely opens;

delivering fuel by a high-pressure pump into a fuel rail; and

influencing a quantity of the delivered fuel by the quantity control valve operated by an electromagnetic operating device, at least one parameter of a braking pulse of the electromagnetic operating device depending on both an efficiency of the electromagnetic operating device and also at least one of (a) a voltage of a voltage source, (b) a temperature, and (c) a temperature of at least one component of at least one of (i) the fuel injection system and (ii) the internal combustion engine;

wherein at least one level of efficiency of the electromagnetic operating device is characterized according to the ascertained pulse duty factor, and

wherein, responsive to the at least one level of efficiency being characterized as having the high level of efficiency, the braking pulse at least one of (a) occurs later, (b) has a shorter duration, and (c) is weaker, than in a case of an electromagnetic operating device having a lower level of efficiency, and

wherein, responsive to the at least one level of efficiency being characterized as having the low level of efficiency, the braking pulse at least one of (a) occurs earlier, (b) has a longer duration, and (c) is stronger, than in a case of an electromagnetic operating device having a higher level of efficiency.