US 7,000,596 B2Granted

Method and apparatus for controlling an internal combustion engine using combustion chamber pressure sensing

AssigneeCummins Westport Inc.

InventorsAxel Zurloye, Dave Ruthmansdorfer, Tim Frazier, Jennifer Rumsey

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Abstract

The present method and apparatus employ a signal indicative of cylinder pressure within the combustion chamber of an internal combustion engine to control combustion phasing or start of combustion (SOC) in subsequent cycles of the engine where the engine is driven by combustion of both a fuel/air premixed charge and a directly injected quantity of fuel. A ratio of signals indicative of pre-combustion pressure and post-combustion pressure within a cycle are employed to estimate SOC and then, based on a predetermined target SOC, an ignition lever is employed to adjust subsequent SOC. A preferred ignition lever is, in a pilot fuel ignited engine, pilot fuel quantity.

Claims58

Dependent claims

A method of controlling combustion of a fuel within a combustion chamber of an internal combustion engine, said method comprising:

(a) during a cycle of said internal combustion engine:
(1) introducing an intake charge into said combustion chamber during an intake event of said cycle, said combustion chamber partially defined by a piston,
(2) introducing a first quantity of said fuel into said combustion chamber during said intake event or a compression event of said cycle, wherein said first quantity of said fuel and said intake charge are compressed and premixed at or near completion of said compression event,
(3) directly injecting a second quantity of said fuel into said combustion chamber when said piston is near top dead center,
(4) burning said fuel in said combustion chamber during a power event of said cycle,
(5) to a controller, delivering a pre-combustion sensor signal (P(A)) determined prior to combustion of said first quantity of said fuel and a first post-ignition sensor signal (P(B)) determined during combustion of said fuel, said sensor signals being indicative of a pressure within said combustion chamber,
(b) calculating an estimated SOC of said first quantity of said fuel within said combustion chamber from said pre-combustion sensor signal and said first post-ignition sensor signal,
(c) during a subsequent cycle of said engine, varying an ignition lever if said estimated SOC of said first quantity of said fuel is different than a predetermined target SOC of said first quantity of said fuel.

5 more elements

A method of controlling combustion of a main fuel within a combustion chamber of an internal combustion engine, said method comprising:

(a) during a cycle of said internal combustion engine:
(1) introducing an intake charge into said combustion chamber during an intake event of said cycle,
(2) introducing a first quantity of said main fuel into said combustion chamber during said intake event or a compression event of said cycle,
(3) introducing a first quantity of a pilot fuel into said combustion chamber at a pilot timing during said intake event or said compression event of said engine, wherein said first quantity of said main fuel, said first quantity of said pilot fuel and said intake charge are compressed and premixed into an auto-ignitable fuel/air charge at or near completion of said compression event said pilot fuel is more auto-ignitable than said main fuel,
(4) directly injecting a second quantity of said main fuel into said combustion chamber when a piston partially defining said combustion chamber is near top dead center,
(5) to a controller, delivering a pre-combustion sensor signal (P(A)) determined prior to combustion of said auto-ignitable fuel/air charge and at least one post-ignition sensor signal determined during combustion of said main fuel, said sensor signals being indicative of a pressure within said combustion chamber,
(b) calculating at least one ratio (Pratio) from said pre-combustion sensor signal and said at least one post-ignition sensor signal, said at least one ratio being indicative of an estimated SOC of said auto-ignitable fuel/air charge within said combustion chamber,
(c) during a subsequent cycle of said engine, varying at least one of said first quantity of said pilot fuel, said pilot timing, said first quantity of said main fuel, if said estimated SOC of said auto-ignitable fuel/air charge is different than a predetermined target SOC of said auto-ignitable fuel/air charge.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/679,026Filed 3 Oct 2003
Published: US 2005/0072402 A17 Apr 2005
Granted: 21 Feb 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

F02D 35/028
On interior conditions: by determining the combustion timing or phasing
F02B 1/12
Engines characterised by fuel-air mixture compression: with compression ignition
F02D 41/3047
With means for triggering compression ignition, e.g. spark plug: said means being a secondary injection of fuel
F02B 2275/14
Other engines, components or details, not provided for in other groups of this subclass: direct injection into combustion chamber