Methods and system for improving accuracy of injecting smaller amounts of fuel to an engine

Patent metadata

Field	Value
Publication number	US-10337442-B2
Application number	US-201615131950-A
Country	US
Kind code	B2
Filing date	Apr 18, 2016
Priority date	Jun 11, 2015
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

Methods and systems for simultaneously operating port fuel injectors and direct fuel injectors of an internal combustion engine are described. In one example, a port fuel injection window is shorted to provide time for scheduling a direct fuel injector pulse width so that the direct fuel injector pulse width may be adjusted so that a desired amount of fuel enters a cylinder.

First claim

The invention claimed is:

1. An engine fueling method, comprising:
determining whether a port fuel injection window is short or long based on a desired pulse width for a port fuel injection of a first cylinder cycle, relative to a threshold pulse width, the short port fuel injection window having a port fuel injection abort angle after an intake valve closing of a cylinder cycle immediately preceding the first cylinder cycle and before an intake valve opening for the first cylinder cycle;
operating with the desired pulse width in the short port fuel injection window; and
in response to determining the port fuel injection window is short:
ending the port fuel injection for the first cylinder cycle at an end time corresponding to at or before the port fuel injection abort angle, the end time adjusted during the short port fuel injection window of the first cylinder cycle; and
scheduling a direct fuel injection, including determining a pulse width and a timing of the direct fuel injection, after the port fuel injection abort angle, the pulse width of the direct fuel injection adjusted for the adjusted end time.

2. The method of claim 1 , where the adjusted end time is adjusted, from a first end time that is based on the desired pulse width, for changes in estimated cylinder air amount during the first cylinder cycle.

3. The method of claim 2 , where the adjusted end time is adjusted multiple times during the short port fuel injection window, after determining the port fuel injection window is short and scheduling the port fuel injection of the first cylinder cycle.

4. The method of claim 3 , where at least a portion of the direct fuel injection occurs during the first cylinder cycle.

5. The method of claim 1 , further comprising:
operating with the desired pulse width for the port fuel injection shorter than the threshold pulse width and determining the port fuel injection window is short responsive to the desired pulse width being shorter than the threshold pulse width; and
operating with the desired pulse width for the port fuel injection longer than the threshold pulse width and determining the port fuel injection window is long responsive to the desired pulse width being longer than the threshold pulse width, wherein the long port fuel injection window has a port fuel injection abort angle before an intake valve closing for the first cylinder cycle and after the intake valve opening of the first cylinder cycle, and, in response to determining the port fuel injection window is long:
ending the port fuel injection for the first cylinder cycle at the end time corresponding to at or before the port fuel injection abort angle, the end time based on the desired pulse width and not adjusted during the long port fuel injection window of the first cylinder cycle; and
scheduling the direct fuel injection, including determining the pulse width and the timing of the direct fuel injection, before the port fuel injection abort angle, the pulse width of the direct fuel injection based on the desired pulse width of the port fuel injection.

6. The method of claim 1 , where a start of port fuel injection time during the first cylinder cycle is after the intake valve closing of the cylinder cycle immediately preceding the first cylinder cycle.

7. The method of claim 1 , where the short port fuel injection window is between a first crankshaft angle and a second crankshaft angle for the first cylinder cycle.

Assignees

• Ford Global Tech Llc

Inventors

• Hollar Paul
• Sanborn Ethan D
• Dusa Daniel
• Zhang Xiaoying
• Thomas Joseph Lyle

Classifications

• F02D41/0007 Primary

  for control of turbo-charged or super-charged engines (control of the pumps per se F02B37/12) · CPC title

• F02D41/221

  relating to the failure of actuators or electrically driven elements · CPC title

• F02D41/182

  for the control of a fuel injection device · CPC title

• F02B5/02

  Methods of operating · CPC title

• F02D2200/0402

  the parameter being determined by using a model of the engine intake or its components · CPC title