Power train control system for internal combustion engine of motor vehicle

• US 5,366,424 A
• Filed: 04/22/1993
• Issued: 11/22/1994
• Est. Priority Date: 04/28/1992
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Wataya, Seiji
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): LARSON, JAMES
• Application Number:
  US08/050,822
• Time in Patent Office: 579 Days
• Field of Search: 123/336, 123/396, 123/399, 74/865, 74/866, 74/867, 477/107, 477/906, 477/907
• US Class Current: 477/107
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02D 11/107 Safety-related aspects
• CPC Class Codes: F16H 59/18 dependent on the position of the accelerator pedal
• CPC Class Codes: F16H 59/24 dependent on the throttle opening
• CPC Class Codes: F16H 61/0213 characterised by the method for generating shift signals
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: Y10S 477/906 Means detecting or ameliorating the effects of malfunction or potential malfunction
• CPC Class Codes: Y10S 477/907 Redundant

Abstract

A power train control system for an internal combustion engine of a motor vehicle. Opening of a throttle valve is electrically controlled in response to an accelerator pedal depression signal generated by an accelerator pedal position sensor and indicating depression depth of an accelerator pedal. A backup operation control of the engine is performed by controlling an auxiliary air flow which bypasses the throttle valve in dependence on the accelerator pedal depression signal upon occurrence of abnormality in a throttle valve control system. During the backup operation, a speed range shift pattern of an automatic transmission is changed over to a backup operation oriented pattern from a normal operation oriented pattern. The power train control system allows the motor vehicle to run even when a failure occurs in the throttle valve or a throttle control system in the fully closed state of the throttle valve.

Claims

1. A power train control system for an internal combustion engine system of a motor vehicle, comprising:

throttle valve control means for electrically controlling an opening degree of a throttle valve in response to an accelerator actuation signal indicative of an actuation level of an accelerator means;

backup control means for controlling an auxiliary air flow which bypasses said throttle valve upon an occurrence of abnormality in said throttle valve control means in accordance with said accelerator actuation signal; and

transmission control means for shifting a speed change pattern of an automatic transmission to a lower gear ratio during a backup operation under the control of said backup control means when compared with that of normal operation.

2. A control system for an internal combustion engine of a motor vehicle, comprising:

a throttle valve disposed within an air intake pipe of said engine for regulating an air flow fed to said engine;

electrical throttle actuator means for operating said throttle valve;

a controller for controlling said electrical throttle actuator means to thereby control an opening of said throttle valve in dependence on an actuation level of an accelerator pedal of said motor vehicle;

an auxiliary air flow passage bypassing said air intake pipe at a location where said throttle valve is disposed;

auxiliary air-flow regulating valve means for controlling an air flow through said auxiliary air flow passage; and

throttle position sensor means for generating a signal indicating the position of said throttle valve;

wherein said controller includes;

decision means for making a decision as to an occurrence of an abnormality in one of said throttle valve, said throttle actuator means, and a control system therefor in a fully closed position of said throttle valve on the basis of the signal supplied from said throttle position sensor; and

control means responsive to an abnormality signal issued by said decision means for activating and controlling said auxiliary air flow regulating means in dependence on the actuation level of said accelerator pedal to thereby allow intake air flow to be supplied to said engine through said auxiliary air flow passage under the control of said auxiliary air-flow regulating valve means;

wherein said motor vehicle is equipped with an automatic transmission, and further comprising;

transmission control means responsive to said abnormality signal to change a speed range shift pattern of said automatic transmission from a normal operation oriented speed range shift pattern to a backup operation oriented speed range shift pattern upon activation of said auxiliary air-flow regulating valve means.

3. A control system for an internal combustion engine of a motor vehicle according to claim 2, wherein gear ratio of said automatic transmission for said backup operation oriented speed range shift pattern is set lower than that for said normal operation oriented speed range shift pattern.

4. A control system according to claim 2, wherein said auxiliary air flow passage is constituted by a bypass air flow passage which is used for idling operation of said engine for warming-up thereof.