US 5,816,217 A · Diesel engine air/fuel ratio controller for black smoke reduction

Abstract

A controller for mechanically setting a diesel engine's air/fuel ratio at a stoichiometric value to reduce black smoke emissions by regulating the quantity of fuel injected into a diesel engine's combustion chamber in response to the quantity of air flow to the engine's cylinder consists of an air flow sensor device and a modulator. The air flow sensor device has a venturi tube located along the engine's air intake conduit, and the modulator is in air communication with the venturi tube via a hollow hose. The modulator is located between a fuel control device, such as an automobile's accelerator pedal, and the engine's fuel injection pump. The modulator consists of an outer shell, internal diaphragm, return spring, push-pull rod and air valve system. The diaphragm divides the modulator's interior cavity into a front chamber and a rear chamber which communicates with the venturi tube. The return spring is located in the rear chamber and urges the diaphragm forwardly so as to expand or enlarge the rear chamber and to contract or diminish the size of the front chamber. One end of the push-pull rod, which is generally axially aligned with the return spring, passes through the front of the modulator's outer shell and connects to the diaphragm; and, the other end of the push-pull rod is operatively connected to control levers for the fuel injector and the accelerator pedal. The air valve system is located between the rear chamber and the outer shell of the front chamber, and is operatively connected to the control levers. The air valve system includes a front valve seat, rear valve seat and an air duct which provides air communication between the ambient and the front and rear chambers.

Claims15

Dependent claims

A controller for adjusting the air/fuel ratio to an engine having a fuel injector and an accelerator operatively connected thereto, said controller comprising:

a device for intercepting at least some air flow entering said engine and for creating a negative pressure proportional to the quantity of said air flow in a pipe means communicating with said intercepting device;
and
a modulator operatively connected to said fuel injector and in air communication with said intercepting device through said pipe means, wherein said modulator mechanically translates said negative pressure communicated through said pipe means into displacements of said fuel injector for adjusting the quantity of fuel being supplied to said engine to substantially maintain an optimum fuel ratio with said air flow for reducing black smoke emissions from said engine, said modulator comprising:
an outer shell forming an interior cavity;
a flexible diaphragm for dividing said interior cavity into a front chamber and a rear chamber, wherein said rear chamber communicates with said pipe means from said
a first biaser disposed within said interior cavity for urging said diaphragm toward said front chamber to expand the rear chamber and contract the front chamber;
and,
an elongate push-pull rod having a rear portion connected to said diaphragm and extending through said front chamber and outer shell, and an opposed front portion located outside said outer shell and operatively connected to a lever for said accelerator and a lever for said fuel injector, said push-pull rod having a hollow interior for accommodating an air valve system which provides for selective air communication between said rear chamber, front chamber and the ambient;
wherein air pressure differentials between said front and rear chambers displace said diaphragm which displacement slides said push-pull rod relative to said outer shell and moves said fuel injector lever to adjust fuel flow to the engine.

6 more elements

A control assembly for adjusting the air/fuel ratio to a diesel engine having a fuel injector and a user controlled accelerator therefor, said control assembly comprising:

an air flow sensor apparatus having a venturi device for intercepting at least some air flow entering said diesel engine and a pipe element communicating with said venturi device, said venturi device creating a negative pressure in said pipe element proportional to the quantity of said air flow;
and
a modulator operatively connected to said fuel injector and in air communication with said air flow sensor apparatus through said pipe element, said modulator mechanically translating said negative pressure communicated through said pipe element into displacements of said fuel injector to adjust the quantity of fuel being supplied to said diesel engine for substantially maintaining an optimum fuel ratio with said air flow to reduce black smoke emissions from said diesel engine.

An improved method of controlling the air/fuel ratio to a diesel engine in which the improvement comprises adjusting the fuel flow to said diesel engine in accordance with the quantity of air flow into said engine with the aid of a control assembly comprising:

a device for intercepting at least some air flow entering said diesel engine and for creating a negative pressure proportional to the quantity of said air flow in a pipe means communicating with said intercepting device;
and
a modulator operatively connected to a fuel injector for said diesel engine and in air communication with said intercepting device through said pipe means, wherein said modulator mechanically translates said negative pressure communicated through said pipe means into displacements of said fuel injector for adjusting the quantity of fuel being supplied to said engine to substantially maintain an optimum fuel ratio with said air flow for reducing black smoke emissions from said diesel engine, said modulator comprising:
an outer shell forming an interior cavity;
a flexible diaphragm for dividing said interior cavity into a front chamber and a rear chamber, wherein said rear chamber communicates with said pipe means from said p2 a first biaser disposed within said interior cavity for urging said diaphragm toward said front chamber to expand the rear chamber and contract the front chamber;
and,
an elongate push-pull rod having a rear portion connected to said diaphragm and extending through said front chamber and outer shell, and an opposed front portion located outside said outer shell and operatively connected to a lever for said accelerator and a lever for said fuel injector, said push-pull rod having a hollow interior for accommodating an air valve system which provides for selective air communication between said rear chamber, front chamber and the ambient;
wherein air pressure differentials between said front and rear chambers displace said diaphragm, which displacement slides said push-pull rod relative to said outer shell and moves said fuel injector lever to adjust fuel flow to the engine.

5 more elements

Dependencies are inferred from the claim text.

Diesel engine air/fuel ratio controller for black smoke reduction

Life of this patent

Diesel engine air/fuel ratio controller for black smoke reduction

Life of this patent

Abstract

Claims15