US 4,237,838 AGranted

Engine air intake control system

AssigneeNippondenso Co., Ltd.

InventorsMasumi Kinugawa, Hideya Fujisawa, Norio Omori, Motoharu Sueishi

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Abstract

A system for controlling the amount of air taken in by an engine comprises an air duct tube bypassing a throttle valve of an intake tube for taking in air supplied to an automobile engine, a plurality of valves for regulating the amount of air passing through the air duct tube, and control device therefor. The amount of air in the bypass is controlled in accordance with the temperature and number of revolutions of the engine and the air intake pressure downstream of the throttle valve. During the idling of the engine, the air intake control system generates a signal representing the standard engine idling revolutions in accordance with the engine temperature, compares the actual engine revolutions with a reference, and regulates the amount of air flowing in the bypass by use of the results of a comparison, thus rendering the actual engine revolutions identical to the reference. During the loaded engine operation, by contrast, the amount of bypass air is so controlled that the air intake pressure downstream of the throttle valve is maintained at predetermined constant value.

Claims14

Dependent claims

In an engine system having throttle means for controlling the amount of air flowing into an engine, an air passage bypassing the throttle means, air control valve means within said bypassing air passage for controlling the flow of air bypassing the throttle means, and fuel supply means for supplying said engine with fuel in accordance with the whole amount of air flowing into said engine through both the throttle means and the bypassing air passage, an apparatus for controlling air flowing into said engine comprising:

temperature detecting means for detecting the temperature of said engine;
speed detecting means for detecting the rotation speed of said engine and generating a rotation speed signal proportional thereto;
reference generating means for generating a reference speed signal representative of a desired idling rotation speed of said engine in response to said temperature detected by said temperature detecting means;
comparing means for comparing said rotation speed signal generated by said speed detecting means with said reference speed signal generated by said reference generating means and providing a comparator signal for controlling said control valve means thereby controlling the amount of air bypassing the throttle means so as to cause the idling rotation speed to be kept at the desired idling rotation speed;
throttle detecting means for detecting the closing and opening of said throttle means;
first control means responsive to said throttle detecting means for allowing and preventing the operation of said air control valve means by said comparing means;
pressure detecting means for detecting the intake pressure present downstream of said throttle means;
and
second control means for causing said air control valve means to increase and decrease the amount of bypass air in response to the output of said pressure detecting means indicative of said intake pressure being below and above a predetermined value, respectively, said second control means providing a control of said air control valve overriding the control provided by said first control means.

6 more elements

An air intake control system for an automobile engine comprising:

an air intake tube for flowing air to said engine;
a throttle valve provided in said air intake tube;
an air passage bypassing said throttle valve;
an air control valve means provided in said bypassing air passage for controlling flow rate of bypass air;
an electromagnetic mechanism for controlling said air control valve means;
an engine speed sensor for detecting the speed of rotation of said engine and generating an engine speed signal related thereto;
a pressure sensor for detecting the pressure of the air intake tube downstream of the throttle valve and generating a pressure signal related thereto;
a function voltage generator circuit for generating a function voltage corresponding to a desired idling speed of rotation;
a closed loop control circuit for regulating the energization of said electromagntic mechanism by comparing the engine speed signal with said function voltage and generating a control circuit signal related to the difference of said signals, said control circuit signal being coupled to said electromagnetic mechanism, thus regulating the idling speed of rotation of said engine at said desired idling speed of rotation;
and
a command circuit impressed with the pressure signal for regulating the energization of said electromagnetic mechanism said regulating overriding the regulation by said closed loop control circuit in a manner such that said pressure in said air intake tube is substantially maintained at a predetermined value during deceleration of the automobile.

8 more elements

A speed control apparatus for an engine having a throttle for controlling the amount of air flowing into the engine and fuel supply means for applying fuel to the engine in accordance with the amount of air flowing thereto, comprising:

an air passage, bypassing the throttle;
a valve disposed within said air passage for controlling the amount of air flow through said air passage, thereby controlling the amount of air bypassing said throttle;
means for sensing the temperature of the engine and generating a temperature signal related thereto;
means for sensing the rotational speed of the engine and generating an actual speed signal related thereto;
means for detecting the open/closed state of said throttle and generating a throttle signal related thereto;
means for generating a desired speed signal representative of a desired speed of said engine;
means for sensing pressure downstream of said throttle and generating a pressure signal related thereto;
means for comparing said actual and desired speed signals and generating a control signal for controlling said valve;
first control means, responsive to said throttle signal for selectively inhibiting the control of said valve by said control signal;
second control means, responsive to said pressure signal for causing said valve to increase or decrease the amount of bypass air flowing therethrough in response to the detected pressure, as represented by said pressure signal, being below or above a predetermined valve, respectively, the control provided by said second control means overriding the control provided by said first control means.

7 more elements

An air intake control system for an automobile engine comprising:

an air intake tube for flowing air to said engine;
a throttle valve provided in said air intake tube;
an air passage bypassing said throttle valve;
a fuel supply means for supplying said engine with fuel in accordance with the whole amount of air flowing into said engine through both the throttle valve and the air passage bypassing the throttle valve;
an air control valve provided in said bypassing air passage for controlling the flow rate of bypass air;
an electromagnetic mechanism for controlling said air control valve;
an engine speed sensor for detecting the speed of rotation of said engine and for generating an engine speed signal related thereto;
a pressure sensor for detecting the pressure at the air intake tube downstream of the throttle valve and for generating a pressure signal related thereto;
a function voltage generator circuit for generating a function voltage corresponding to a desired idling speed of rotation of said engine;
a closed loop control circuit for regulating the energization of said electromagnetic mechanism by comparing the engine speed signal with said function voltage and generating a control circuit signal related to the differences of said signals, said control circuit signal being coupled to said electromagnetic mechanism, thus regulating the idling speed of rotation of said engine at said desired idling speed of rotation;
and
a command circuit impressed with said pressure signal for regulating the energization of said electromagnetic mechanism, said regulating overriding the regulation provided by said closed loop control circuit in a manner such that the pressure in said air intake tube is substantially maintained at a predetermined value during deceleration of the automobile.

9 more elements

Dependencies are inferred from the claim text.