SYSTEM AND METHOD FOR DETECTING CYLINDER MISFIRE

• US 20090234562A1
• Filed: 03/11/2008
• Published: 09/17/2009
• Est. Priority Date: 03/11/2008
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Johnson, Thomas M., Wolf, Adam J., Klingaman, Wes
• Granted Patent: US 7,788,020 B2
• Time in Patent Office: Days
• US Class Current: 701/108
• CPC Class Codes: F02D 2200/1015 Engines misfires
• CPC Class Codes: F02D 2400/08 Redundant elements, e.g. two sensors for measuring the same parameter
• CPC Class Codes: F02D 41/0072 Estimating, calculating or determining the EGR rate, amount or flow sensors in EGR systems F02M26/45
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/1498 measuring engine roughness
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/47 the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: G01M 15/11 by detecting misfire
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system for detecting individual cylinder misfire in a multiple cylinder internal combustion (IC) engine having exhaust gas recirculation (EGR). The system includes: a device for predicting EGR flow rate on a cylinder to cylinder basis; a device for sensing actual EGR flow rate on a cylinder to cylinder basis with all cylinders firing; and a device for comparing the predicted EGR flow rate to the actual EGR flow to determine individual cylinder misfire.

Claims

1. A system for detecting individual cylinder misfire in multiple cylinder internal combustion (IC) engine having exhaust gas recirculation (EGR), said system comprising:

a device for predicting EGR flow rate on a cylinder to cylinder basis;

a device for sensing actual EGR flow rate on a cylinder to cylinder basis with all cylinders firing; and

a device for comparing the predicted EGR flow rate to the actual EGR flow to determine individual cylinder misfire.

2. A system as claimed in claim 1, wherein said engine includes a fuel system and an engine electronic control module (ECU) and said system further comprises a combustion management strategy within said ECU to correct misfire.

3. A system as claimed in claim 2, wherein said combustion management strategy is one of at least adjusting fuel rate and quantity and combustion timing.

4. A system as claimed in claim 1, wherein said EGR flow rate is detected by a device sensing differential pressure across an obstruction.

5. A system as claimed in claim 4 wherein said device is one of a venturi, orifice, nozzle, segmental wedge, V-cone and Dall tube.

6. A system as claimed in claim 5 wherein said device is a venturi.

7. A system as claimed in claim 5 wherein said device is an orifice.

8. A system as claimed in claim 2, wherein said engine has a crank angle sensor to correlate the crank angle to activity in individual cylinders.

9. A system as claimed in claim 8, wherein said device for comparing predicted and actual EGR flow stores a history of EGR flow to predict current EGR flow.

10. A system as claimed in claim 9, wherein said corrected action is one of adjusting fueling rate and/or quantity and combustion timing.

11. A method of determining individual cylinder misfiring in a multiple cylinder misfiring in a multiple cylinder internal combustion engine (IC) engine having exhaust gas recirculation (EGR) comprising the steps of:

predicting EGR flow rate on a cylinder to cylinder basis with all cylinders firing;

sensing actual EGR flow rate on a cylinder to cylinder basis; and

comparing the predicted EGR flow rate to the actual EGR flow rate to determine individual cylinder misfiring.

12. A method as claimed in claim 11, wherein said internal combustion engine has a fuel system and electronic control unit (ECU) and wherein said method comprises the further step of correcting misfire determined by said system.

13. A method as claimed in claim 12, wherein said corrected step is one of adjusting fueling rate and/or quantity and combustion timing.

14. A method as claimed in claim 11, wherein said EGR flow rate is detected by a device sensing differential pressure across an obstruction.

15. A method as claimed in claim 14 wherein said device is one of a venturi, orifice, nozzle, segmental wedge, V-cone and Dall tube.

16. A method as claimed in claim 15 wherein said device is a venturi

17. A method as claimed in claim 15 wherein said device is an orifice

18. A method as claimed in claim 11, comprising the further step of correlating the crank angle of the engine to individual cylinder conditions.

19. A method as claimed in claim 18, comprising the further step of storing the history of EGR flow and comparing actual EGR flow to correct predicted EGR flow.