Change gear control device using acceleration and gear ratio as parameters for automatic transmission in a motor vehicle and the method therefor

• US 5,643,133 A
• Filed: 02/01/1994
• Issued: 07/01/1997
• Est. Priority Date: 02/25/1991
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kimura, Hiroshi, Minowa, Toshimichi, Yoshida, Yoshiyuki, Nishimura, Yutaka, Ohyama, Yoshishige
• Primary Examiner(s): TA, KHOI QUANG
• Application Number:
  US08/189,782
• Time in Patent Office: 1,246 Days
• Field of Search: 477/107, 477/109, 477/97, 477/110, 477/111, 477/102, 123/344
• US Class Current: 477/107
• 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 10/11 Stepped gearings
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 2710/0622 Air-fuel ratio
• CPC Class Codes: B60W 30/18 Propelling the vehicle
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 2400/12 Engine control specially adapted for a transmission comprising a torque converter or for continuously variable transmissions
• CPC Class Codes: F02D 41/0225 in relation with the gear ratio or shift lever position
• CPC Class Codes: F02D 41/023 in relation with the gear ratio shifting conjoint control for improving gear change B60W30/19
• CPC Class Codes: F16H 2061/0018 Transmission control for optimising exhaust emissions
• CPC Class Codes: F16H 2306/42 Changing the input torque to the transmission
• CPC Class Codes: F16H 59/14 Inputs being a function of torque or torque demand
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 59/48 Inputs being a function of acceleration
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: F16H 61/16 Inhibiting or initiating shift during unfavourable conditions, e.g. preventing forward reverse shift at high vehicle speed, preventing engine over speed unintentional control input F16H61/18
• CPC Class Codes: F16H 63/502 for smoothing gear shifts
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A change gear control device is provided for an automatic transmission in a motor vehicle propelled by an internal combustion engine which is operated with an air/fuel mixture having air/fuel ratios ranging from a fuel rich air/fuel ratio to a fuel lean air/fuel ratio depending on driving conditions of the motor vehicle. In this device a first detector detects an engine torque of the internal combustion engine and a second detector detects a vehicle speed of the motor vehicle. A processor processes transmission gear ratios for the automatic transmission. In particular, the processor reads the detected engine torque from the first detector and the detected vehicle speed from the second detector, determines a new transmission gear ratio based upon the engine torque and the vehicle speed, and outputs a signal representing the new transmission gear ratio to the automatic transmission, whereby a gear shifting operation is effected at a timing based on an engine torque variation due to an operating air/fuel ratio change.

Claims

1. A method of controlling an internal combustion engine of a motor vehicle which is operated with air fuel mixture gas having air fuel ratio ranging from a fuel rich air fuel ratio to a fuel lean air fuel ratio depending on driving conditions of the motor vehicle and which is equipped with an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque comprising the steps of:

(A) detecting gear ratio change when a shift-up command is generated while throttle opening degree is unchanged;

maintaining a fuel lean air fuel ratio unchanged; and

retarding ignition timing for the engine during gear change operation in response to the detection of the gear ratio change;

(B) detecting an instant when an engine torque exceeds a predetermined level when the throttle opening degree is increased without causing gear shifting; and

reducing air fuel ratio in response to the detection of engine torque exceeding the predetermined level;

(C) detecting gear ratio change when the throttle opening degree is increased and a shift-down command is generated; and

delaying the timing of air fuel ratio reduction toward the end of gear change operation in response to detection of the gear ratio change;

(D) detecting gear ratio change when the throttle opening degree is decreased and shift-up command is generated; and

delaying the timing of air fuel ratio reduction toward the end of gear change operation in response to the detection of the gear ratio change;

(E) detecting gear ratio change when the throttle opening degree is decreased and a shift-up command is generated;

reducing air fuel ratio in response to the shift-up command; and

retarding ignition timing for the engine during gear change operation in response to the detection of the gear ratio change.

2. A method of controlling an internal combustion engine of a motor vehicle which is operated with air fuel mixture gas having air fuel ratio ranging from a fuel rich air fuel ratio to a fuel lean air fuel ratio depending on driving conditions of the motor vehicle and which is equipped with an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque comprising the steps of:

detecting the shift lever position of the automatic transmission; and

inhibiting engine operation with air fuel mixture gas having air fuel ratio at more than 14.7 when the shift lever position is determined to be other than a position which provides a plurality of reduction gear ratios.

3. A method of controlling an internal combustion engine of a motor vehicle which is operated with an air fuel mixture gas having air fuel ratios ranging from a fuel rich air fuel ratio to a fuel lean air fuel ratio depending on driving conditions of the motor vehicle and which is equipped with an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque comprising the steps of:

detecting gear ratio change when a shift-up command is generated while a throttle opening degree is unchanged;

maintaining a fuel lean air fuel ratio unchanged; and

retarding an ignition timing for the engine during a gear change operation in response to the detection of the gear ratio change.

4. A method of controlling an internal combustion engine of a motor vehicle which is operated with an air fuel mixture gas having air fuel ratios ranging from a fuel rich air fuel ratio to a fuel lean air fuel ratio depending on driving conditions of the motor vehicle and which is equipped with an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque comprising the steps of:

detecting an instant when an engine torque exceeds a predetermined level when a throttle opening degree is increased without causing gear shifting; and

reducing an air fuel ratio in response to the detection of an engine torque exceeding over the predetermined level.

5. A method of controlling an internal combustion engine of a motor vehicle which is operated with an air fuel mixture gas having air fuel ratios ranging from a fuel rich air fuel ratio to a fuel lean air fuel ratio depending on driving conditions of the motor vehicle and which is equipped with an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque comprising the steps of:

detecting gear ratio change when a throttle opening degree is increased and a shift-down command is generated; and

delaying a timing of an air fuel ratio reduction toward the end of a gear change operation in response to the detection of the gear ratio change.

6. A method of controlling an internal combustion engine of a motor vehicle which is operated with an air fuel mixture gas having air fuel ratios ranging from a fuel rich air fuel ratio to a fuel lean air fuel ratio depending on driving conditions of the motor vehicle and which is equipped with an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque comprising the steps of:

detecting gear ratio change when a throttle opening degree is decreased and a shift-up command is generated; and

delaying a timing of an air fuel ratio reduction toward the end of a gear change operation in response to the detection of the gear ratio change.

7. A method of controlling an internal combustion engine of a motor vehicle which is operated with an air fuel mixture gas having air fuel ratios ranging from a fuel rich air fuel ratio to a fuel lean air fuel ratio depending on driving conditions of the motor vehicle and which is equipped with an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque comprising the steps of:

detecting gear ratio change when a throttle opening degree is decreased and a shift-up command is generated;

reducing an air fuel ratio in response to the shift-up command; and

retarding an ignition timing for the engine during a gear change operation in response to the detection of the gear ratio change.

8. A device for controlling an internal combustion engine of a motor vehicle which is operated with an air fuel mixture gas having air fuel ratios ranging from a fuel rich air fuel ratio to a fuel lean air fuel ratio comprising:

means for changing-over an air fuel ratio of the air fuel mixture gas depending on driving conditions of the motor vehicle;

an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque; and

means for offsetting a timing of an air fuel ratio change-over toward the end of a gear change operation, whereby an engine torque fluctuation during the gear change operation is suppressed.

9. A device for controlling an internal combustion engine of a motor vehicle which is operated with an air fuel mixture gas having air fuel ratios ranging from a fuel rich air fuel ratio to a fuel lean air fuel ratio comprising:

means for changing-over an air fuel ratio of the air fuel mixture gas depending on driving conditions of the motor vehicle;

an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque; and

means for retarding an ignition timing during a change gear operation, whereby an engine torque fluctuation during the gear change operation is suppressed.

10. A device for controlling an internal combustion engine of a motor vehicle which is operated with an air fuel mixture having an air fuel ratio ranging from fuel rich air fuel ratio to a fuel lean air fuel ratio comprising:

means for changing-over an air fuel ratio of the air fuel mixture gas depending on driving conditions of the motor vehicle;

an automatic transmission of which gear change is determined based on a vehicle speed and an engine torque; and

means for retarding an ignition timing during a change gear operation spanning from generation of a shift command to completion of shifting operation, whereby an engine torque fluctuation during the gear change operation is suppressed.