Diesel EGR control

• US 6,880,524 B2
• Filed: 04/15/2002
• Issued: 04/19/2005
• Est. Priority Date: 04/15/2002
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Gates, Freeman Carter, Bina, Hossein
• Primary Examiner(s): Wolfe, Jr., Willis R.
• Application Number:
  US10/063,350
• Publication Number:
  US 20030192517A1
• Time in Patent Office: 1,100 Days
• Field of Search: 123/568.11, 123/568.12, 123/568.18, 123/568.16, 123/568.21, 123/568.19, 123/361, 123/399, 123/478, 123/480, 701/108, 701/104, 701/105
• US Class Current: 123/399
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02D 11/10 of the electric type
• CPC Class Codes: F02D 13/0219 by shifting the phase, i.e. the opening periods of the valves are constant
• CPC Class Codes: F02D 2041/0017 by simultaneous control of throttle and exhaust gas recirculation
• 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 41/1445 the characteristics being related to the exhaust flow
• CPC Class Codes: F02D 9/02 concerning induction conduits throttle valves, or arrangements thereof in conduits F02D9/08
• CPC Class Codes: F02M 26/23 Layout, e.g. schematics
• CPC Class Codes: F02M 26/47 the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: F02M 26/50 Arrangements or methods for preventing or reducing deposits, corrosion or wear caused by impurities arrangement or layout of EGR passages with means for cleaning or treating the recirculated gases F02M26/35; protection of EGR valves from damage F02M26/74
• CPC Class Codes: F02M 26/53 using electric actuators, e.g. solenoids
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for controlling a diesel engine exhaust gas recirculation system is described. In particular, a simplified diesel engine system is provided where presence of exhaust gas recirculation of flow is controlled via a two-position valve, while a quantity of exhaust gas recirculation is adjusted by varying the throttle valve. In this way, a reduced cost diesel exhaust gas recirculation system is achieved that provides the functionality of having variable amounts of exhaust gas recirculation.

Claims

1. A system comprising:

a diesel fuel engine having an intake manifold and an exhaust manifold;

an exhaust gas recirculation passage coupled between said engine intake manifold and said engine exhaust manifold;

a two-position solenoid valve positioned in said exhaust gas recirculation passage;

a variable area throttle valve coupled to said intake manifold; and

a controller for calculating an actual amount of exhaust gas flowing through said passage and adjusting said throttle valve based on said actual exhaust gas flow so that said actual exhaust gas flow approaches a desired exhaust gas flow.

2. The system recited in claim 1 wherein said two-position solenoid valve is electronically controlled based on engine operating conditions.

3. The system recited in claim 2 wherein said variable area throttle valve adjusts airflow entering the engine.

4. The system recited in claim 1 wherein said controller further adjusts an amount of injected diesel fuel based on a desired engine output.

5. The system recited in claim 1 wherein said actual exhaust gas recirculation flow is estimated based on pressure upstream and downstream of said two-position valve.

6. A system comprising:

a diesel engine having an intake manifold and an exhaust manifold;

an electronically controlled throttle valve coupled to said intake manifold of said diesel engine, where fresh airflow passes by said throttle valve;

an exhaust gas recirculation passage connecting said intake manifold and said exhaust manifold of said diesel engine;

a two-position solenoid valve positioned in said exhaust gas recirculation passage; and

a sensing unit for sensing pressure upstream and downstream of said two-position solenoid valve.

7. The system recited in claim 6 wherein said sensing unit comprises a differential sensor for sensing a differential pressure between pressure upstream and downstream of said two-position solenoid valve.

8. The system recited in claim 6 wherein said sensing unit comprises a first sensor for measuring absolute pressure upstream of said two-position solenoid valve and a second sensor for measuring absolute pressure downstream of said two-position solenoid valve.

9. The system recited in claim 8 wherein said second sensor is coupled to said intake manifold of said diesel engine.

10. The system recited in claim 6 further comprising a diesel fuel injection valve coupled to said diesel engine.

11. A system for an internal combustion engine having a manifold with a first and second inlet, the system comprising:

a throttle coupled to the first inlet;

an exhaust gas recirculation unit coupled to the second inlet, where recirculated exhaust flow travels from an engine exhaust to the manifold, said unit comprising a restriction in said flow; and

a controller for determining an actual exhaust gas recirculation amount based on a first pressure upstream of said restriction and a second pressure downstream of said restriction, adjusting said throttle based on a requested exhaust gas recirculation amount and said determined amount, and adjusting a diesel fuel injection amount in the engine based on an operating condition.

12. The system recited in claim 11 wherein said restriction is a two-position valve.

13. The system recited in claim 11 wherein said restriction is a two-position valve that can be either substantially open or substantially closed.

14. The system recited in claim 11 wherein determining of actual exhaust gas recirculation amount based on said first pressure upstream of said restriction and said second pressure downstream of said restriction includes determining actual exhaust gas recirculation based on a differential pressure between said first and second pressure.

15. A system comprising:

a diesel fuel engine having an intake manifold and an exhaust manifold;

an exhaust gas recirculation passage coupled between said engine intake manifold and said engine exhaust manifold;

a two-position valve positioned in said exhaust gas recirculation passage;

a variable area throttle valve coupled to said intake manifold; and

a controller for, during engine operation, adjusting said throttle valve to adjust an amount of exhaust gas flow through said exhaust gas recirculation passage while adjusting a fuel injection amount to adjust engine output and while maintaining said solenoid valve at a first position.

16. The system recited in claim 15 wherein said two-position solenoid valve is electronically controlled based on engine operating conditions.

17. The system recited in claim 15 wherein said two-position solenoid valve is a two-position solenoid valve.

18. The system recited in claim 16 wherein said variable area throttle valve adjusts airflow entering the engine.