METHOD AND APPARATUS TO DETERMINE MAGNITUDE OF COMBUSTION CHAMBER DEPOSITS

• US 20080156081A1
• Filed: 03/14/2008
• Published: 07/03/2008
• Est. Priority Date: 11/16/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: University of Michigan
• Inventors: Filipi, Zoran S., Assanis, Dionissios N., Rask, Rodney B., Najt, Paul M., Kuo, Tang-Wei, Hoffman, Mark A., Guralp, Orgun A., Eng, James A.
• Granted Patent: US 7,637,251 B2
• Time in Patent Office: Days
• US Class Current: 73/114.02
• CPC Class Codes: F02B 23/0672 Omega-piston bowl, i.e. the combustion space having a central projection pointing towards the cylinder head and the surrounding wall being inclined towards the cylinder center axis the surrounding wall being exactly vertical F02B23/0696
• CPC Class Codes: F02D 13/0234 changing the valve timing only
• CPC Class Codes: F02D 35/02 on interior conditions
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 35/025 by determining temperatures inside the cylinder, e.g. combustion temperatures
• CPC Class Codes: F02D 35/028 by determining the combustion timing or phasing
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method to dynamically determine a parametric value for combustion chamber deposits (CCD), e.g. in a controlled auto-ignition engine, including in-situ evaluation of thickness of CCD, based on a sensor which monitors combustion in a homogeneous charge compression ignition engine. It includes a temperature sensor operative to monitor the combustion chamber, and a CCD parameter that is based upon a peak combustion temperature measured at a crank angle. A CCD parameter can also be determined utilizing an in-cylinder pressure monitor, wherein a combustion chamber deposit parameter is based upon crank angle location of a peak in-cylinder pressure parameter.

Claims

1. Method for determining a parameter for combustion chamber deposits of an internal combustion engine adapted to be operative in a controlled auto-ignition combustion mode, said engine comprising a spark-ignition, direct-injection, four-stroke, internal combustion engine including a variable volume combustion chamber defined by a piston reciprocating within a cylinder between top-dead-center and bottom-dead-center points and a cylinder head, said piston operably connected to a rotating crankshaft, the method comprising:

monitoring a combustion parameter; and

determining a combustion chamber deposit parameter based upon the combustion parameter.

2. The method of claim 1, wherein monitoring the combustion parameter comprises monitoring a combustion chamber surface temperature and a related engine crank angle.

3. The method of claim 2, wherein determining a combustion chamber deposit parameter based upon the combustion parameter comprises:

determining magnitude of combustion chamber deposits based upon an engine crank angle at which a peak combustion chamber surface temperature occurs during an engine cycle.

4. The method of claim 1, wherein monitoring the combustion parameter further comprises:

monitoring a related engine crank angle;

determining an in-cylinder combustion pressure parameter during each engine cycle; and

determining the combustion pressure parameter based upon a peak in-cylinder pressure and the crank angle location of the peak in-cylinder pressure.

5. The method of claim 4, wherein determining the in-cylinder combustion pressure parameter comprises monitoring output of an in-cylinder pressure sensing device.

6. The method of claim 4, wherein determining the in-cylinder combustion pressure parameter comprises monitoring an in-cylinder spark ionization signal.

7. A method for operating a multi-cylinder direct-injection, four-stroke internal combustion engine capable of operating with a controlled auto-ignition process, comprising:

determining a parametric measure of combustion chamber deposits; and

,

controlling engine operation based upon the combustion chamber deposit parameter.

8. The method of claim 7, wherein determining a parametric measure of combustion chamber deposits comprises:

monitoring a combustion parameter; and

determining a parametric measure of combustion chamber deposits based upon combustion parameter.

9. The method of claim 8, wherein determining a parametric measure of combustion chamber deposits based upon combustion parameter comprises:

determining magnitude of combustion chamber deposits based upon an engine crank angle at which a peak combustion chamber surface temperature occurs during an engine cycle.

10. The method of claim 8, wherein monitoring the combustion parameter further comprises:

monitoring a related engine crank angle;

determining an in-cylinder combustion pressure parameter during each engine cycle; and

determining the combustion pressure parameter based upon a peak in-cylinder pressure and the crank angle location of the peak in-cylinder pressure.

11. The method of claim 10, wherein determining the in-cylinder combustion pressure parameter comprises monitoring output of an in-cylinder pressure sensing device.

12. The method of claim 10, wherein determining the in-cylinder combustion pressure parameter comprises monitoring an in-cylinder spark ionization signal.