Method and system for ignition energy control

Patent metadata

Field	Value
Publication number	US-9458773-B2
Application number	US-201414279025-A
Country	US
Kind code	B2
Filing date	May 15, 2014
Priority date	May 15, 2014
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

Methods and systems are provided for improving spark robustness. Spark ignition dwell commands are adjusted based on the fuel fraction delivered via direct injection relative to port injection. The approach allows ignition output to better match the ignition requirement of the given fuel combination.

First claim

The invention claimed is:

1. A method for an engine, comprising:
adjusting an ignition coil dwell time for a cylinder spark event based on fuel received in the cylinder via port injection relative to direct injection.

2. The method of claim 1 , wherein the adjusting includes adjusting based on a proportion of a total amount of fuel that is received in the cylinder via the port injection relative to the proportion of the total amount of fuel that is received in the cylinder via the direct injection.

3. The method of claim 2 , wherein the adjusting further includes adjusting based on a first fuel received in the cylinder via the port injection relative to a second fuel received direct injection.

4. The method of claim 3 , wherein the engine includes a single coil ignition system and wherein the adjusting includes, in response to a higher proportion of the total amount of fuel being delivered via direct injection at lower engine speeds and loads, increasing the ignition coil dwell time, and in response to a higher proportion of the total amount of fuel being delivered via port injection at higher engine speeds and loads, increasing the ignition coil dwell time.

5. The method of claim 4 , wherein the adjusting further includes, as the alcohol content of the second fuel delivered via direct injection increases, increasing the ignition coil dwell time.

6. The method of claim 3 , wherein the engine includes a dual coil ignition system having a first ignition coil and a second ignition coil coupled to a common cylinder spark plug, and wherein the adjusting includes, in response to a higher proportion of the total amount of fuel being delivered via direct injection, increasing the dwell time of at least the first ignition coil.

7. The method of claim 6 , wherein the first ignition coil is charged and discharged earlier than the second ignition coil, and wherein the adjusting further includes increasing a time between discharging of the first coil and discharging of the second coil as the proportion of the total amount of fuel delivered via the direct injection increases.

8. The method of claim 1 , wherein the adjusting includes adjusting from an initial dwell time estimate based on engine operating conditions including engine speed and load to a final dwell time estimate based on fuel received in the cylinder via port injection relative to direct injection.

9. A method for an engine, comprising:
during a cylinder spark event,

adjusting a dwell time of each of a first ignition coil and a second ignition coil coupled to a cylinder spark plug based on cylinder fueling via a direct injector and via a port injector.

10. The method of claim 9 , further comprising, adjusting a time elapsed between discharging of the first ignition coil and discharging of the second ignition coil based on the cylinder fueling.

11. The method of claim 10 , wherein the cylinder fueling includes a first fuel received in the cylinder via the port injector and a second fuel received in the cylinder via the direct injector.

12. The method of claim 11 , wherein the dwell time of the first ignition coil is increased and the dwell time of the second ignition coil is increased as a difference in alcohol content between the first fuel and the second fuel increases.

13. The method of claim 12 , wherein the time elapsed between discharging of the first ignition coil and discharging of the second ignition coil is increased as the difference in alcohol content between the first fuel and the second fuel increases.

14. The method of claim 13 , wherein the cylinder fueling further includes a relative proportion of the cylinder fueling received via the direct injector as compared to the port injector.

15. The method of claim 14 , wherein the dwell time of the first ignition coil is increased and the dwell time of the second ignition coil is increased as the relative proportion of cylinder fueling delivered via the direct injector increases.

16. The method of claim 15 , wherein the time elapsed between discharging of the first ignition coil and discharging of the second ignition coil is increased as the relative proportion of cylinder fueling delivered via the direct injector increases.

17. An engine system, comprising:
an engine cylinder including a single spark plug;
an ignition system including a first ignition coil and a second ignition electrically coupled to the single spark plug;
a port injector for port injecting a first fuel to the cylinder;
a direct injector for direct injecting a second fuel to the cylinder; and
a controller including instructions stored in non-transitory memory to:
supply different charging current times via a single conductor to the first and the second ignition coils, the different charging current times based on the first and second fuels, and further based on a proportion of cylinder fueling via the direct injector relative to the port injector; and
discharge each of the first and second ignition coil to the single spark plug.

18. The system of claim 17 , wherein the controller includes further instructions for adjusting a delay between discharging the first ignition coil and discharging the second ignition coil to the single spark plug based on the cylinder fueling.

19. The system of claim 18 , wherein the different charging current times include a first charging current provided to the first ignition coil and a second charging current provided to the second ignition coil, and wherein the first charging current is increased by a smaller amount and the second charging current is increased by a larger amount as the proportion of cylinder fueling received via the direct injector increases relative to the port injector.

20. The system of claim 19 , wherein each of the first charging current, second charging current, and delay is further adjusted based on ignitability of a first fuel delivered via the direct injector relative to the ignitability of a second fuel delivered via the port injector, the delay decreased as a difference in ignitability between the first fuel and the second fuel increases.

Assignees

• Ford Global Tech Llc

Inventors

• Glugla Chris Paul
• Huberts Garlan J

Classifications

• Y02T10/36

  Cross-Sectional Technologies · mapped topic

• F02P3/045

  for control of the dwell or anti dwell time · CPC title

• F02P9/002

  Control of spark intensity, intensifying, lengthening, suppression (by means of current control in the storage devices F02P3/05, F02P3/09, during starting F02P15/12) · CPC title

• Y02T10/46

  Cross-Sectional Technologies · mapped topic

• F02D19/0689

  for in-cylinder direct injection · CPC title