Engine control system for hybrid vehicle

• US 6,352,489 B1
• Filed: 03/07/2000
• Issued: 03/05/2002
• Est. Priority Date: 03/09/1999
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Uchida, Keisuke, Iwata, Yoichi, Nakamoto, Yasuo, Kuroda, Shigetaka, Sawamura, Kazutomo
• Primary Examiner(s): Marmor, Charles A.
• Assistant Examiner(s): Lewis, Tisha D.
• Application Number:
  US09/520,628
• Time in Patent Office: 728 Days
• Field of Search: 477/2, 477/7, 477/8, 477/11, 477/5, 477/14, 475/5, 475/8, 180/65.1, 180/65.5
• US Class Current: 477/5
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 15/20 for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: F02N 11/0822 related to action of the driver
• CPC Class Codes: F02N 11/0833 Vehicle conditions F02N11/0822, F02N11/0825 take precedence
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/914 Actuated, e.g. engaged or disengaged by electrical, hydraulic or mechanical means
• CPC Class Codes: Y10S 903/919 : Stepped shift
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch
• CPC Class Codes: Y10S 903/951 : Assembly or relative location of components

Abstract

The engine control system for a hybrid vehicle, according to the present invention, having an internal combustion engine and an electric motor as driving force sources, comprises: a clutch, provided between the engine and a transmission system, for disabling and enabling driving force transmission between the engine and the transmission system; clutch disengagement detector for detecting engagement/disengagement of the clutch; engine speed detector for detecting an engine speed; and fuel cutter for permitting stopping and restarting of the engine in accordance with at least a result of detection by the clutch disengagement detector among predetermined drive conditions, and cutting fuel supply to the engine when the vehicle decelerates, a fuel-supply restart engine speed at which fuel supply is resumed being set in the fuel cutter. Stopping the engine is accomplished by cutting fuel supply by the fuel cutter, and once the engine stop is initiated, even when the engine speed reaches the fuel-supply restart engine speed, fuel supply cut by the fuel cutter is maintained, and when the engine speed detected by the engine speed detector at a time of disengagement of the clutch is detected by the clutch disengagement detector is equal to or lower than a predetermined engine speed, fuel supply cut by the fuel cutter is maintained whereas when the detected engine speed is higher than the predetermined engine speed, fuel supply is restarted.

Claims

1. An engine control system for a hybrid vehicle, having an internal combustion engine and an electric motor as driving force sources, comprising:

a clutch, operable by an operator of the vehicle, provided between said engine and a manually-operated transmission system, for disabling and enabling driving force transmission between said engine and said transmission system;

a clutch disengagement detector for detecting engagement or disengagement of said clutch;

an engine speed detector for detecting an engine speed; and

a fuel cutter for permitting stopping and restarting of said engine in accordance with at least a result of detection by said clutch disengagement detector among predetermined drive conditions, and cutting fuel supply to said engine when said vehicle decelerates, a fuel-supply restart engine speed at which fuel supply is resumed being set in said fuel cutter,

wherein said stopping engine is accomplished by cutting fuel supply by said fuel cutter, and

wherein once the engine stop control is initiated, even when said engine speed reaches said fuel-supply restart engine speed, fuel supply cut by said fuel cutter is maintained, and when said engine speed detected by said engine speed detector at a time of disengagement of said clutch is detected by said clutch disengagement detector is equal to or less than a predetermined engine speed, fuel supply cut by said fuel cutter is maintained whereas when said detected engine speed is greater than said predetermined engine speed, fuel supply is restarted.

2. The engine control system according to claim 1, wherein fuel supply cut by said fuel cutter is maintained at least when a shift position of said vehicle running at a vehicle speed equal to or less than a predetermined value is other than a reverse position and low position.

3. The engine control system according to claim 1 or 2, wherein a condition for stopping said engine is that a brake pedal is actuated.

4. The engine control system according to claim 1, 2, or 3, wherein said predetermined engine speed is equal to or less than an idling speed.