Control system for internal combustion engine

• US 6,505,464 B1
• Filed: 11/09/2000
• Issued: 01/14/2003
• Est. Priority Date: 11/09/1999
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Ando, Hiroyuki, Isobe, Takashi, Tsutsumi, Kojiro, Niki, Manabu
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): NGUYEN, TU MINH
• Application Number:
  US09/708,685
• Time in Patent Office: 796 Days
• Field of Search: 602/74, 602/77, 602/84, 603/00
• US Class Current: 60/277
• CPC Class Codes: F01N 2550/00 Monitoring or diagnosing the deterioration of exhaust systems
• CPC Class Codes: F01N 3/2006 Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2200/0804 Estimation of the temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/0255 to accelerate the warming-up of the exhaust gas treating apparatus at engine start
• CPC Class Codes: F02D 41/064 at cold start F02D41/067 takes precedence
• CPC Class Codes: F02D 41/068 for warming-up
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: F02P 5/1506 with particular means during starting
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A control system is disclosed that accelerates the rise in temperature of a catalyst provided in an exhaust system of an internal combustion engine. The system increases the intake air amount after the engine starts and retards the ignition timing according to a rotational speed of the engine. In this control system, a failure of the catalyst temperature rise acceleration control is diagnosed according to the engine rotational speed and/or a retard amount of the ignition timing during the execution of the catalyst temperature rise acceleration control. The above failure may also be diagnosed according to at least one of the ignition timing and the engine rotational speed when decreasing the intake air amount during the execution of the catalyst temperature rise acceleration control. The above failure may also be diagnosed according to a detected catalyst temperature and an estimated catalyst temperature.

Claims

1. A control system for internal combusting engine having an exhaust system provided with a catalyst, said control system comprising:

intake air amount control means for controlling an intake air amount to said engine;

ignition timing control means for controlling an ignition timing of said engine;

catalyst temperature raising means for increasing the intake air amount after starting of said engine and for retarding the ignition timing according to a rotational speed of said engine; and

failure diagnosing means for diagnosing a failure of said catalyst temperature raising means during the operation of said catalyst temperature raising means, wherein

failure diagnosing means diagnoses said failure of said catalyst temperature raising means according to an amount of change in said ignition timing during the operation of said catalyst temperature raising means.

2. A control system for internal combusting engine having an exhaust system provided with a catalyst, said control system comprising:

intake air amount control means for controlling an intake air amount to said engine;

ignition timing control means for controlling an ignition timing of said engine;

catalyst temperature raising means for increasing the intake air amount after starting of said engine and for retarding the ignition timing according to a rotational speed of said engine;

failure diagnosing means for diagnosing a failure of said catalyst temperature raising means during the operation of said catalyst temperature raising means;

intake air temperature detecting means for detecting an intake air temperature to said engine; and

coolant temperature detecting means for detecting a coolant temperature of said engine, wherein the failure diagnosis by said failure diagnosing means is inhibited when the difference between the detected coolant temperature and the detected intake air temperature is greater than or equal to a predetermined temperature.

3. A control system for internal combusting engine having an exhaust system provided with a catalyst, said control system comprising:

intake air amount control means for controlling an intake air amount to said engine;

ignition timing control means for controlling an ignition timing of said engine;

catalyst temperature raising means for increasing the intake air amount after starting of said engine and for retarding the ignition timing according to a rotational speed of said engine;

failure diagnosing means for diagnosing a failure of said catalyst temperature raising means during the operation of said catalyst temperature raising means; and

load detecting means for detecting a load on said engine, wherein the failure diagnosis by said failure diagnosing means is inhibited when the detected load is less than a predetermined value.

4. A control system for internal combustion engine having an exhaust system provided with a catalyst, said control system comprising:

intake air amount control means for controlling an intake air amount to said engine;

ignition timing control means for controlling an ignition timing of said engine;

catalyst temperature raising means for increasing the intake air amount after starting of said engine and for retarding the ignition timing according to a rotational speed of said engine; and

failure diagnosing means for diagnosing a failure of said catalyst temperature raising means during the operation of said catalyst temperature raising means, wherein the failure diagnosing means determines that the catalyst temperature raising means has failed when a retard amount of the ignition timing after the elapse of a predetermined time period from the time of starting the operation of the catalyst temperature raising means is less than or equal to a predetermined retard amount.

5. A control system according to claim 4, wherein said failure diagnosing means diagnoses said failure of said catalyst temperature raising means according to a crank angle position at which the rotational speed of said engine during the operation of said catalyst temperature raising means becomes maximum.

6. A control system according to claim 4, wherein said catalyst temperature raising means operates when the rotational speed of said engine is greater than or equal to a predetermined lower limit rotational speed and said engine is in an idling condition.

7. A control system according to claim 4, further comprising:

coolant temperature detecting means for detecting a coolant temperature of said engine, wherein an operating time period of said catalyst temperature raising means is set according to the coolant temperature detected when starting said engine.

8. A control system according to claim 4, wherein said catalyst temperature raising means sets the retard amount of the ignition timing so that the rotational speed of said engine coincides with a target rotational speed.

9. A control system for internal combustion engine having an exhaust system provided with a catalyst, said control system comprising:

intake air amount control means for controlling an intake air amount to said engine;

ignition timing control means for controlling an ignition timing of said engine;

catalyst temperature raising means for increasing the intake air amount after starting of said engine and for retarding the ignition timing according to a rotational speed of said engine; and

failure diagnosing means for diagnosing a failure of said catalyst temperature raising means during the operation of said catalyst temperature raising means, wherein the failure diagnosing means determines that the catalyst temperature raising means has failed when a retard amount of the ignition timing after the elapse of a predetermined time period from the time of starting the operation of the catalyst temperature raising means is less than or equal to a predetermined retard amount and the rotational speed of the engine after the elapse of a predetermined time period from the time of starting the operation of the catalyst temperature raising means is less than or equal to a predetermined rotational speed.