Engine control apparatus

• US 6,335,573 B1
• Filed: 07/31/2000
• Issued: 01/01/2002
• Est. Priority Date: 08/02/1999
• 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: Eguchi, Takahiro, Izumiura, Atsushi
• Primary Examiner(s): Waks, Joseph
• Application Number:
  US09/629,981
• Time in Patent Office: 519 Days
• Field of Search: 290/40.C, 290/40.R, 290/40.A, 290/17, 180/65.2, 180/65.4, 477/107, 477/112, 477/181, 123/179.3, 123/179.4
• US Class Current: 290/40.00C
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60K 6/543 the transmission being a continuously variable transmission
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/101 Infinitely variable gearings
• 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 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 30/18018 Start-stop drive, e.g. in a traffic jam
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: F16H 2061/023 Drive-off gear selection, i.e. optimising gear ratio for drive off of a vehicle
• CPC Class Codes: F16H 59/78 Temperature
• CPC Class Codes: F16H 61/66 specially adapted for continuously variable gearings control of exclusively fluid gearing F16H61/38
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/918 : Continuously variable
• CPC Class Codes: Y10S 903/945 : Characterized by control of gearing, e.g. control of transmission ratio

Abstract

An engine control apparatus is provided for a hybrid vehicle that installs an engine and a motor as driving power sources for driving wheels as well as an automatic transmission such as CVT. The engine control apparatus basically operates to enable automatic stop and restart of the engine in response to drive conditions of the vehicle. In addition, the engine control apparatus cuts off fuel supply to the engine at a deceleration mode of the vehicle. At a deceleration mode of the vehicle under execution of fuel cut, the engine control apparatus maintains idle rotation of the engine by operating the motor to rotate in response to engine speed until the automatic transmission is returned to a restart-enable reduction ratio (e.g., 2.2 to 2.45). That is, the engine control apparatus allows execution of an engine stop after securing a restart-enable state of the automatic transmission. Incidentally, the motor produces motor torque, which is increased in response to decrease of the engine speed in a range between 700 and 1000 rpm, then, which is maintained at a prescribed value (e.g., 8.5 kgf-m), for example.

Claims

1. An engine control apparatus for a vehicle in which wheels are driven by driving power being produced by an engine and transmitted by way of an automatic transmission, said engine control apparatus comprising:

an engine stop/restart device that stops or restarts the engine in response to prescribed drive conditions of the vehicle;

a fuel cut device that cuts off fuel supply to the engine at a deceleration mode of the vehicle; and

a detection device that detects that the automatic transmission returns a reduction ratio thereof to a restart-enable reduction ratio, so that the engine stop/restart device allows execution of an engine stop.

2. An engine control apparatus for a hybrid vehicle which uses an engine and a motor as driving power sources for driving wheels, comprising:

an engine stop/restart device that stops or restarts the engine in response to prescribed drive conditions of the hybrid vehicle;

a fuel cut device that cuts off fuel supply to the engine at a deceleration mode of the hybrid vehicle;

an engine speed detection device that detects engine speed of the engine;

a reduction ratio detection device that detects a reduction ratio of an automatic transmission; and

a motor control device that maintains an idle rotation speed of the engine by operating the motor to rotate in response to the engine speed under execution of fuel cut at the deceleration mode until the automatic transmission returns the reduction ratio thereof to a restart-enable reduction ratio.

3. An engine control apparatus according to claim 2 wherein the motor control device controls the motor to increase motor torque in response to decrease of the engine speed.

4. An engine control method for a vehicle in which wheels are driven by driving power being produced by an engine and transmitted by way of an automatic transmission, said engine control method comprising the steps of:

automatically stopping or restarting the engine in response to prescribed drive conditions of the vehicle;

cutting off fuel supply to the engine at a deceleration mode of the vehicle; and

detecting that the automatic transmission returns a reduction ratio thereof to a restart-enable reduction ratio, thus allowing execution of an engine stop.

5. An engine control method for a hybrid vehicle which uses an engine and a motor as driving power sources for driving wheels, comprising the steps of:

automatically stopping or restarting the engine in response to prescribed drive conditions of the hybrid vehicle;

cutting off fuel supply to the engine at a deceleration mode of the hybrid vehicle;

detecting engine speed of the engine;

detecting a reduction ratio of an automatic transmission; and

maintaining an idle rotation speed of the engine by operating the motor to rotate in response to the engine speed under execution of fuel cut at the deceleration mode until the automatic transmission returns the reduction ratio thereof to a restart-enable reduction ratio.