Claims
- 1. A method of controlling an exhaust gas parameter in an internal combustion engine having a piston which reciprocates to provide intake, compression, combustion, and exhaust strokes, said method using an exhaust gas recirculation event and an intake valve event, and comprising the steps of:generating exhaust gas back pressure in the engine; monitoring an exhaust gas parameter level; and carrying out an exhaust gas recirculation event responsive to the level of the parameter, wherein the exhaust gas parameter is controlled by selectively varying an overlap period between the exhaust gas recirculation event and the intake valve event.
- 2. The method of claim 1 wherein the parameter comprises engine manifold pressure.
- 3. The method of claim 1 wherein the parameter comprises engine manifold pressure.
- 4. The method of claim 1 wherein the parameter comprises engine cylinder pressure.
- 5. The method of claim 1 wherein the parameter comprises engine cylinder temperature.
- 6. The method of claim 1 further comprising the step of:selectively controlling the duration of the exhaust gas recirculation event to control the mass charge in the cylinder.
- 7. The method of claim 6 wherein the exhaust gas recirculation event lasts until after the piston has completed a substantial portion of its compression stroke.
- 8. The method of claim 1 wherein the exhaust gas recirculation event lasts until after the piston has completed a substantial portion of its compression stroke.
- 9. The method of claim 1 further comprising the step of:selectively controlling the lift of an exhaust valve opened for the exhaust gas recirculation event to control the mass charge in the cylinder.
- 10. The method of claim 1 wherein an exhaust valve opened for the exhaust gas recirculation event is opened prior to the end of the intake stroke and is closed after the piston has completed a substantial portion of the compression stroke.
- 11. A system for controlling the level of an exhaust gas parameter in an internal combustion engine by varying the overlap between an exhaust gas recirculation event and an intake valve event, comprising:means for monitoring the level of an exhaust gas parameter; and means for selectively opening an exhaust valve to carry out an exhaust gas recirculation event in the engine in response to the exhaust gas parameter attaining a predetermined level, wherein the exhaust valve is opened at such a time as to provide an overlap between the exhaust gas recirculation event and an intake valve event that will prevent the parameter from substantially exceeding the predetermined level.
- 12. The system of claim 11 wherein the parameter comprises a pressure.
- 13. The system of claim 12 wherein the pressure occurs in an exhaust manifold.
- 14. The system of claim 12 wherein the pressure occurs in a cylinder of said engine.
- 15. The system of claim 11 wherein the parameter comprises a temperature.
- 16. The system of claim 15 wherein the temperature occurs in an exhaust manifold of said engine.
- 17. The system of claim 15 wherein the temperature occurs in a cylinder of said engine.
- 18. A method of optimizing engine performance of an internal combustion engine having a piston which reciprocates to provide intake, compression, combustion, and exhaust strokes, and in which overlapping exhaust gas recirculation and intake valve events are carried out, said method comprising the steps of:increasing the overlap of the exhaust gas recirculation and intake valve events when the engine is placed in a positive power producing mode; and decreasing the overlap of the exhaust gas recirculation and intake valve events when the engine is placed in an engine braking mode.
- 19. The method of claim 18 wherein the step of increasing the overlap comprises carrying out the entire exhaust gas recirculation event during some portion of the intake valve event.
- 20. The method of claim 18 further comprising the step of:carrying out the exhaust gas recirculation event until after substantial portion of the compression stroke is completed.
- 21. A method of providing NOx control in an internal combustion engine during positive power comprising the step of selectively turning on and off the EGR event responsive to positive power and non-positive power modes of engine operation.
- 22. The method of claim 21 wherein the EGR event occurs entirely within the main exhaust event.
- 23. The method of claim 21 wherein EGR is regulated by selectively varying the opening and closing points and the magnitude of exhaust valve opening.
Parent Case Info
This application claims benefit for Provisional application Ser. No. 60/060,785 filed Oct. 3, 1997.
US Referenced Citations (9)
Provisional Applications (1)
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Number |
Date |
Country |
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60/060785 |
Oct 1997 |
US |