Output speed dependent throttle control system for internal combustion engine

• US 4,671,235 A
• Filed: 02/06/1985
• Issued: 06/09/1987
• Est. Priority Date: 02/07/1984
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Hosaka, Akio
• Primary Examiner(s): Argenbright, Tony M.
• Application Number:
  US06/698,872
• Time in Patent Office: 853 Days
• Field of Search: 123/352, 123/361, 123/399, 123/400, 123/401, 123/478, 123/436, 180/176, 180/179
• US Class Current: 123/352
• CPC Class Codes: B60K 31/107 the memory being digital
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 2011/102 at least one throttle being moved only by an electric actuator
• CPC Class Codes: F16H 2059/084 Economy mode
• CPC Class Codes: F16H 2059/085 Power mode
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A throttle valve control system for an internal combustion engine electrically controls throttle valve angular position in order to control intake air flow rate through an air induction passage of an engine. The system employs an accelerator to produce a signal representative of a required or demanded output speed. Actual output speed is monitored by means of a speed sensor. The actual speed is compared with the output speed demand derived from the accelerator signal to obtain the difference therebetween. Feedback control is performed on the basis of the calculated difference so as to control the throttle valve angular position to increase or decrease the actual output speed toward the speed demand value.

Claims

1. An intake flow rate control system for an internal combustion engine comprising:

a manually operable speed demand input means for producing a speed demand indicative signal having a value varying according to preset variation characteristics in accordance with manual operation;

a manually operable mode selector for selecting one of various distinct variation characteristics of the speed demand, and wherein said speed demand indicative signal value varies dependinq upon the selected mode;

a first sensor, associated with a vehicular power train including said engine, for monitoring the actual output speed of said power train and producing an actual speed indicative signal having a value proportional to the output speed of the power train;

an intake air flow rate adjusting means, associated with an air induction passage of the engine, for controlling air flow therethrough, said intake air flow rate adjusting means being responsive to a control signal to adjust the intake air flow rate in accordance therewith; and

a controller receiving said speed demand indicative signal and said actual speed indicative signal and deriving the difference between the signal values thereof, said controller producing said control signal having a value corresponding to the derived difference and thereby controlling said intake air flow rate adjusting means to adjust the actual output speed of said power train toward the manually input speed demand.

2. The control system as set forth in claim 1, wherein said speed demand input means comprises a manually operable accelerator serving as a movable element of an accelerator position signal generator producing said speed demand indicative signal according to the manually selected position of said accelerator.

3. The control system as set forth in claim 2, wherein said intake air flow rate adjusting means comprises a throttle valve disposed within said air induction passage and an electrically operable servo system associated with said throttle valve for adjusting the open degree of said throttle valve according to said control signal.

4. An air induction rate control system for an internal combustion engine comprising:

a manually operable accelerator for controlling air induction rate through an air induction passage;

a manually operable mode selector switch movable to any of a plurality of switch positions, each corresponding to a preset operational mode;

a throttle valve disposed pivotably within said air induction passage, the angular position of which depends upon the manually selected position of said accelerator;

a first sensor associated with said accelerator for producing a first sensor signal having a value varying according to the position of the accelerator;

wherein speed demand characteristics relative to said first sensor signal value are adjusted in accordance with the selected operational mode;

a second sensor monitoring output of a power train including said engine and producing a second sensor signal having a value indicative of the output speed of said power train;

a third arithmetic means, responsive to said first sensor signal for deriving an output speed demand on the basis of said first sensor signal value, said third arithmetic means is responsive to the switch position of said mode selector switch for selecting one of preset speed demand characteristics corresponding to the selected mode, and derives the speed demand in terms of said first sensor signal value in accordance with the selected characteristics;

a fourth arithmetic means, responsive to said second sensor signal and the output of said first arithmetic means, for deriving the difference between said second sensor signal value and said first arithmetic means output value and deriving a control signal having a value corresponding to the derived difference between the second sensor signal value and said first arithmetic means output value; and

a throttle value servo mechanism responsive to said control signal for adjusting the throttle valve angular position by an amount corresponding to the value of said control signal.

5. The control system as set forth in claim 4, wherein said power train comprises said engine and a power transmission having an output shaft, and said second sensor is associated with said transmission output shaft for monitoring output speed on said output shaft.

6. The control system as set forth in claim 4, wherein said first sensor is an electrical signal generator and part of said accelerator serves as a movable electro-active element of said signal generator.

7. A throttle valve control system for an internal combustion engine comprising:

a manually operable accelerator;

a throttle valve disposed within an air induction passage of the engine for controlling intake air flow rate therethrough;

an electrically operable throttle valve servo mechanism associated with said throttle valve to control the open degree of the latter according to a control signal;

a manually operable mode selector for selecting one of a plurality of preset operation modes of the control system, each of which has unique speed demand variation characteristics relative to a first sensor signal value;

a first sensor associated with said accelerator for monitoring the position of said accelerator and producing said first sensor signal indicative of the position of said accelerator;

a power train including said engine and having an output shaft for driving vehicular driving wheels;

a second sensor associated with said output shaft of said power train for monitoring output speed thereon, said second sensor producing a second sensor signal indicative of the output speed on said output shaft;

a controller receiving said first sensor signal and second signal, deriving an output speed demand on the basis of said first sensor signal value according to preset characteristics of variation of output speed demand depending upon said first sensor signal value, said controller uses one of a plurality of preset characteristics depending upon the mode selected by said manually operable mode selector deriving the difference between the derived output speed demand and said second sensor signal value representative of the actual output speed, and generating a control signal acting on said throttle valve servo mechanism so as to reduce said difference to zero.

8. A process for controlling intake air flow rate through an air induction system of an internal combustion engine by means of a throttle valve, comprising the steps of:

selecting one of a plurality of distinct variation characteristics of desired speed relative to the accelerator position, and wherein the desired speed value is derived in accordance with the selected desired speed variation characteristics;

deriving a desired magnitude of speed to be outputted through a power train including the engine on the basis of the position of a manual accelerator;

monitorig actual output speed on said power train;

calculating the difference between said desired speed and said actual speed;

deriving a control signal having a value acting to reduce the difference between said desired speed and said actual output speed toward zero; and

feedback controlling a throttle valve servo system associated with said throttle valve so as to actuate said throttle value to a degree corresponding to the control signal value.

9. The process as set forth in claim 8, wherein said control signal is an electrical signal for operating said servo system electrically.