Internal combustion engine shutdown method and control system

• US 6,425,365 B1
• Filed: 10/20/2000
• Issued: 07/30/2002
• Est. Priority Date: 10/20/2000
• Status: Expired due to Term

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Peters, Mark William, Robichaux, Jerry D., Kotre, Stephen John, Boggs, David Lee
• Primary Examiner(s): Kamen, Noah P.
• Application Number:
  US09/692,918
• Time in Patent Office: 648 Days
• Field of Search: 123/520, 123/568.12, 123/198.DB
• US Class Current: 123/198.0DB
• CPC Class Codes: B60K 6/442 Series-parallel switching type
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: F02D 41/0032 Controlling the purging of the canister as a function of the engine operating conditions
• CPC Class Codes: F02D 41/0055 Special engine operating conditions, e.g. for regeneration of exhaust gas treatment apparatus
• CPC Class Codes: F02D 41/042 for stopping the engine
• CPC Class Codes: F02M 25/08 adding fuel vapours drawn from engine fuel reservoir electrical control of purge system F02D41/003
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

Periodic shutdown of the internal combustion engine (12) during operation of a hybrid electric vehicle (HEV) is achieved by shutdown of a vapor management valve (VMV) of the engine evaporative emission control system and an EGR valve (150) of the tailpipe emission control system at the time an engine shutdown command is provided to a controlled engine shutdown routine that, after closing of the VMV and EGR valves, then commands disabling of the engine fuel injectors (160) in a manner to stop engine operation.

Claims

1. A method of controlling an internal combustion engine having a plurality of fuel injectors, an evaporative emission control system including a vapor management valve between a fuel tank and an engine intake manifold, and an EGR valve between an engine exhaust manifold and the intake manifold, comprising closing said vapor management valve and said EGR valve prior to disabling of said fuel injectors as part of an engine shutdown routine in response to an engine shutdown command and, after said closing, said routine commanding disabling of said fuel injectors in a manner to stop engine operation, thereby eliminating contributions of fuel to said intake manifold from said vapor management valve and said EGR valve prior to stopping of said engine.

2. In a method of operating a hybrid electric vehicle where an internal combustion engine is stopped and restarted in response to commands from a vehicle system controller, the improvement comprising stopping the internal combustion engine according to claim 1.

3. A method of controlling an internal combustion engine having a plurality of fuel injectors, an evaporative emission control system including a vapor management valve between a fuel tank and an engine intake manifold, and an EGR valve between an engine exhaust manifold and the intake manifold, comprising closing said vapor management valve and said EGR valve as part of an engine shutdown routine in response to an engine shutdown command and, after said closing, said routine commanding disabling of said fuel injectors in a sequence over a predetermined time period to stop engine operation.

4. The method of claim 3 including rotating a crankshaft of the internal combustion engine for a second predetermined time after said predetermined time period using an electric motor of a hybrid electric vehicle.

5. The method of claim 4 wherein said routine further commands an ignition spark during the predetermined time periods until engine speed drops below a predetermined value.

6. For use with an internal combustion engine having a plurality of fuel injectors, an evaporative emission control system including a vapor management valve between a fuel tank and an engine intake manifold, and an EGR valve between an engine exhaust manifold and the intake manifold, an engine control system that commands closure of said vapor management valve and said EGR valve at a time when an engine shutdown command is received and that, after said closure, commands disabling of the fuel injectors in sequence over a predetermined time period to stop engine operation.

7. The system of claim 6 that commands rotation of a crankshaft of the internal combustion engine for a second predetermined time after said predetermined time period.

8. The system of claim 7 that enables the ignition system to fire the spark plugs during the predetermined time periods until engine speed drops below a predetermined value.

9. For use with an internal combustion engine having a plurality of fuel injectors, an evaporative emission control system including a vapor management valve between a fuel tank and an engine intake manifold, and an EGR valve between an engine exhaust manifold and the intake manifold, an engine control system that commands closure of said vapor management valve and said EGR valve prior to disabling of said fuel injectors when an engine shutdown command is received and that, after said closure, commands disabling of the fuel injectors in a manner to stop engine operation, thereby eliminating contributions of fuel to said intake manifold from said vapor management valve and said EGR valve prior to stopping of said engine.

10. A hybrid electric vehicle having an electric motor and an internal combustion engine controlled by the system of claim 9.

11. A hybrid electric vehicle having an electric motor, an internal combustion engine having a plurality of fuel injectors, an evaporative emission control system including a fuel vapor storage canister with a purge valve between a fuel tank and an engine intake manifold, and an EGR valve between an engine exhaust manifold and the intake manifold, and an engine control system for controlling said internal combustion engine and having an engine shutdown routine that commands closure of said purge valve and said EGR valve prior to disabling of said fuel injectors when an engine shutdown command is received and that, after said closure, commands disabling of said fuel injectors in a manner to stop engine operation, thereby eliminating contributions of fuel to said intake manifold from said purge valve and said EGR valve prior to stopping of said engine.

12. An electronic memory containing a computer program to be executed by an engine controller which controls fuel injectors supplying fuel to the engine, a canister purge valve between a fuel tank and an engine intake manifold, and an EGR valve between an engine exhaust manifold and the intake manifold, comprising an engine shutdown code means that commands closure of said purge valve and said EGR valve prior to disabling of said fuel injectors when an engine shutdown command is received and that, after said closure, commands disabling of said fuel injectors in a manner to stop engine operation, thereby eliminating contributions of fuel to said intake manifold from said purge valve and said EGR valve prior to stopping of said engine.