FORM 2
THE PATENT ACT 1970 (as amended)
[39 OF 1970]
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
[See Section 10 and Rule 13]
TITLE: “A METHOD OF MAINTAINING IDEAL AIR-FUEL MIXTURE
AND A SYSTEM”
NAME AND ADDRESS OF THE APPLICANT: TATA MOTORS LIMITED, an Indian company having its registered office at Bombay house, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001, Maharashtra, INDIA.
Nationality: INDIAN
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.

TECHNICAL FIELD
Embodiments of the present disclosure relate to vehicle combustion system. More particularly, the disclosure relates to a method and a system for maintaining ideal air-fuel mixture for obtaining complete combustion.
BACKGROUND AND PRIOR ARTS
A gasoline engine burns gasoline in the presence of oxygen. For complete combustion of the gasoline and to extract maximum energy from the fuel it should be burnt with the specific amount oxygen (In turn Air) may be termed as Perfect (ideal) Ratio. This ratio is different for different fuels. For example for gasoline, it is 14.7:1. Amount of air required for complete combustion of the fuel depends on the amount of Hydrogen & Carbons present in the fuel. If amount of air is less than the required value the ratio is called as “Rich” mixture. Rich mixture is not acceptable as amount of un-burn gases are more & it creates pollution. On the other hand if amount of air more than the required ratio it creates lean ratio. Lean ratio is also harmful as it produces Nitrogen-Oxides pollution. It results in poor performance & may cause engine damage.
Engines have to work on an ideal (perfect) air to fuel ratio so as to have high fuel efficiency and low emissions. Modern day engines comprises of O2 sensors which monitors the amount of oxygen present in the exhaust gases, and gives feedback to the Engine Management Unit (EMU). The EMU controls the amount of fuel to be injected and works in closed loop system where exhaust gases are continuously monitored & feedback is provided to engine management unit.
To increase the power of the engine it is important to remember that power does not come from oxygen boost; it comes from burning more fuel in the same amount of time. With adequate fuel supply and oxygen boost in some form it is possible to greatly increase output without having to increase the RPM range or displacement of an engine.
Hence, there exist a need to develop a methodology and a system to maintain the ideal air to fuel mixture to achieve high fuel efficiency and low emissions.

OBJECTS OF THE DISCLSOURE
One object of the disclosure is to provide a method of maintaining the ideal air-fuel mixture ratio in the engine for complete combustion.
One object of the disclosure is to provide O2 sensor to ensure that engine gets the correct mixture of fuel and oxygen, regardless of altitude, engine temperature and air flow to make sure it's removing harmful pollutants from exhaust.
One object of the disclosure is to produce more power of the engine and reduce excessive emissions as much as possible.
STATEMENT OF THE DISCLOSURE
Accordingly, the present disclosure provides for a method of maintaining ideal air-fuel mixture in an Engine, said method comprising sensing at least one of oxygen content in atmosphere and mass flow rate of intake air by a sensor; receiving at least one of sensed oxygen content in the atmosphere and mass flow rate of the intake air by Engine Management Unit (EMU) and comparing with pre-set threshold oxygen content and mass flow rate respectively; and activating a control valve to inject oxygen from oxygen storage to reconditioning chamber through an oxygen injector when the EMU sends control signal to the control valve to maintain the ideal air-fuel mixture in the engine, wherein the EMU generates control signals when sensed at least one of oxygen content in the atmosphere and mass flow rate of the intake air is less than pre-set threshold oxygen content and mass flow rate respectively, and depending on opening of engine valve and throttle input, and also provides for a System for maintaining air-fuel mixture in an Engine, said system comprising an Engine Management Unit (EMU), an air intake unit comprising an inlet and an outlet; a reconditioning chamber connected to the outlet of the air intake unit; an intake manifold connected between the reconditioning chamber and the engine; characterized in that, an oxygen sensor connected between the air intake unit and the EMU configured for sensing at least one of oxygen content in atmosphere and mass flow rate of intake air; a control valve communicatively connected to the EMU for receiving control signals for activation; an oxygen storage configured for supplying oxygen to the reconditioning chamber through an oxygen injector upon activation of the control valve for maintaining air-fuel mixture in the engine.

SUMMARY OF THE DISCLOSURE
The shortcomings of the prior art are overcome and additional advantages are provided through the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.
In one embodiment, the disclosure provides a method of maintaining ideal air-fuel mixture in an Engine, said method comprising sensing at least one of oxygen content in atmosphere and mass flow rate of intake air by a sensor. Engine Management Unit (EMU) receives at least one of sensed oxygen content in the atmosphere and mass flow rate of the intake air and compares with pre-set threshold oxygen content and mass flow rate respectively; and a control valve is activated to inject oxygen from oxygen storage to reconditioning chamber through an oxygen injector when the EMU sends control signal to the control valve to maintain the ideal air-fuel mixture in the engine, wherein the EMU generates control signals when at least one of sensed oxygen content in the atmosphere and mass flow rate of the intake air is less than preset threshold oxygen content and mass flow rate respectively. In combination with the sensed oxygen content and mass flow rate, opening of engine valve and throttle input are also considered to activate the control valve.
In one embodiment, the method further comprises recirculating exhaust gas to the reconditioning chamber for drying of the intake air.
In one embodiment, the preset value of the oxygen to be injected is dependent on engine swept volume.
A system for maintaining air-fuel mixture in an Engine is disclosed as one aspect of the present disclosure. The system comprises an Engine Management Unit (EMU) and an air intake unit comprising an inlet and an outlet. The system also includes a reconditioning chamber connected to the outlet of the air intake unit; an intake manifold connected between the reconditioning chamber and the engine. The system further includes an oxygen sensor which is connected between the air intake unit and the EMU configured for sensing at least one of oxygen content in atmosphere and mass flow rate of intake air. In addition to above a control valve is provided with the

system which is communicatively connected to the EMU for receiving control signals for activation. An oxygen storage configured for supplying oxygen to the reconditioning chamber through an oxygen injector upon activation of the control valve is also provided for maintaining air-fuel mixture in the engine.
In one embodiment, the EMU generates control signals when at least one of sensed oxygen content in the atmosphere and mass flow rate of the intake air is less than preset threshold oxygen content and mass flow rate respectively, and depending on opening of engine valve and throttle input.
In one embodiment, the system is provided with a solenoid operated needle valve for controlling amount of oxygen injection into the reconditioning chamber.
In one embodiment, the reconditioning chamber is connected with a recirculation means for supplying exhaust gas for drying the intake air.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
FIG. 1 shows a system for maintaining air-fuel mixture in an Engine, and
FIG. 2 shows flow chart illustrating method of maintaining ideal air-fuel mixture in
the Engine.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that

alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
In the following detailed description, reference is made to the accompanying figures, which form a part hereof. In the figures, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, and figures are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.
Referral numerals

Referral numeral Description
1 A system for maintaining ideal air-fuel mixture
2 Engine
3 Air Intake unit
3a Inlet of air intake unit
3b Outlet of air intake unit
4 Reconditioning chamber
5 Oxygen sensor
6 Engine Management Unit
7 Control Valve
8 Oxygen Storage
9 Oxygen Injector
10 Intake manifold
11 Recirculation means
12 Solenoid operated needle valve

FIG. 1 illustrates a system (1) for maintaining ideal air-fuel mixture in an Engine (2). The system (1) comprises air intake unit (3), a reconditioning chamber (4) connected to the air intake unit (3), an intake manifold (10) connected between the reconditioning chamber (4). The system (1) is configured with an oxygen sensor (5) connected between the air intake unit (3) and an Engine Management Unit [EMU] (6). A control valve (7) is connected with oxygen storage (8), an oxygen injector (9) and the EMU (6). An oxygen injector (9) is connected between a control valve (7) and the reconditioning chamber (4). The size of control valve (7) is dependent on the size of the engine, wherein the size should be at least 1.3 times engine capacity for natural aspirated engines and 1.1 times for turbocharged engines. The reconditioning chamber
(4) always has positive pressure and should be free from pressure fluctuation. Also,
the reconditioning chamber is used to maintain the intake air temperature within
predetermined value. Further, a solenoid operated needle valve (12) is provided
between the control valve (7) and the oxygen injector (9) to control the quantity of
oxygen injection into the reconditioning chamber (4). The oxygen sensor (5) senses
oxygen content in the atmospheric air and mass flow of air intake to provide signals to
the EMU (6), and the EMU (6) is configured to activate the control valve (7) to
supply the oxygen to the Engine (2). The ideal air-fuel mixture for gasoline is 14.7:1.
The reconditioning chamber (4) in the system (1) is connected with a recirculation
means for supplying exhaust gas for drying the intake air.
FIG. 2 illustrates a method of maintaining ideal air-fuel mixture in an Engine. At step 201, the oxygen content present in the atmosphere is sensed using an oxygen sensor
(5) of the system and also mass flow rate of air intake is also sensed. At step 202, the
sensed oxygen content and mass flow rate is received by the Engine Management
Unit (EMU). At step 203, the sensed oxygen content and mass flow rate is compared
with the preset threshold oxygen content and mass flow rate. The preset threshold
oxygen content and mass flow rate value is a value which is required to maintain the
ideal air-fuel mixture. If anyone of the value goes less than the preset value, ideal air-
fuel mixture cannot be achieved. Hence, EMU compares the sensed oxygen content
and mass flow rate and compares with the prerecorded value. At step 204, if the
compared oxygen content and mass flow rate is less than the preset threshold values,
then at step 205, the activation of control valve (7) is carried out. Further activation of

control valve (7) is also dependent on opening of engine valve and throttle input. Upon activation of the control valve, the required oxygen from oxygen storage (8) is supplied to the reconditioning chamber (4). Thus at step 206, the air-fuel mixture ratio is maintained as ideal fuel mixture for complete combustion. The additional supply of air to the engine having lean mixture enriches intake air by 3-4% more oxygen depending upon the altitude and oxygen content present in the intake air.
If the air-fuel mixture is more than the ratio of ideal air-fuel ratio, i.e. rich mixture, as described in the step 206, the signals from EMU sends signal to increase the throttle opening to supply more fuel to make the mixture ideal/perfect for complete combustion of fuel.
If the sensed oxygen and mass flow rate of intake air at step 204, is more than the preset threshold oxygen content and mass flow rate, then at step 207, the intake oxygen is supplied to engine for combustion.
Further certain quantity of the exhaust gas is passed into the reconditioning chamber (4) so as to make the intake air dry by 5 %. The dried air is further supplied to the Intake manifold (10) to the Engine (2). Thus, the air entering into the engine is made dry in order to ensure that the combustion of the injected fuel occurs completely due to dry air. The drying of air can be controlled by controlling the exhaust air to the recirculating chamber.
Ideally an engine takes in Air (Oxygen and Nitrogen) and fuel (hydrocarbons) and produces CO2, H2O, and the N2 just passes straight through. The related chemical equation is as follows.
C8H18 + 125 O2 + 3.76N2 = 8 CO2 + 9H2O + 12.5 (3.76 N2)
The chemical equation assumes complete combustion Stoichiometric ratio of air and for the gasoline the ideal air-fuel ratio (perfect ratio) is 14.7:1.
Further, the technology of the instant application is further elaborated with the help of following example. However, the example should not be construed to limit the scope of the invention.

Example 1:
Engines having specific swept volume for e.g. 800 cc, will use 800 cc air in one cycle. Oxygen content is measured at the intake with the help of EMU [is also referred as Engine Control Unit (ECU)] and calculates the quantity of oxygen to be injected into the conditioning chamber. The Ideal air-fuel ratio is dependent on the fuel that is being used in the vehicle engine. For various fuels, the ideal or perfect air-fuel ratios are, for natural gas, 17.2:1, for Gasoline: 14.7:1, for propane: 15.5:1, for ethanol 9:1, for methanol 6.4:1, for hydrogen 34:1, and for diesel 14.6:1.
Advantages:
Due to full combustion of the air fuel mixture, more power is produced by low volume engine.
Emission level will be reduced as there will be more oxygen available to perform complete combustion.
Less pollution as the exhaust gases mixing in the atmosphere through exhaust system is less.
The amount of oxygen the engine can absorb/supplied depends on factors such as the altitude and the temperature of the air and engine. The system is useful for higher altitude as atmospheric air is coarse. Also, low volume engine can be operated at high power and higher speeds.
The O2 sensor ensure that engine gets the correct mixture of fuel and oxygen, regardless of altitude, engine temperature and air flow to make sure it's removing harmful pollutants from exhaust. The goal of the sensor is to help in produce more power of the engine and reduce excessive emissions as much as possible.
The system disclosed in the present disclosure works independent of altitude whenever there is less oxygen content in the atmosphere.
Industrial applicability:
The disclosed method and system finds its potential application in IC Engines, such as
automobiles and generators.

Equivalents
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should typically be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a

convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

We claim:
1. A method of maintaining ideal air-fuel mixture in an Engine (2), said method
comprising:
sensing at least one of oxygen content in atmosphere and mass flow rate of intake air by a sensor (5);
receiving at least one of sensed oxygen content in the atmosphere and mass flow rate of the intake air by Engine Management Unit (EMU) (6) and comparing with preset threshold oxygen content and mass flow rate respectively; and
activating a control valve (7) to inject oxygen from oxygen storage (8) to reconditioning chamber (4) through an oxygen injector (9) when the EMU (6) sends control signal to the control valve (7) to maintain the ideal air-fuel mixture in the engine,
wherein the EMU (6) generates control signals when at least one of sensed oxygen content in the atmosphere and mass flow rate of the intake air is less than pre-set threshold oxygen content and mass flow rate respectively, and depending on opening of engine valve and throttle input.
2. The method as claimed in claim 1, wherein the method further comprises recirculating exhaust gas to the reconditioning chamber (4) for drying of the intake air.
3. The method as claimed in claim 1, wherein the preset value of the oxygen to be injected is dependent on engine swept volume.
4. The method as claimed in claim 1, wherein when the air-fuel mixture is more than the ratio of ideal air-fuel ratio EMU (6) generates signals to increase the throttle opening to supply more fuel to make the mixture ideal for complete combustion of the fuel.
5. A System (1) for maintaining air-fuel mixture in an Engine (2), said system comprising:
an Engine Management Unit (EMU) (6);
an air intake unit (3) comprising an inlet (3a) and an outlet (3b);

a reconditioning chamber (4) connected to the outlet (3b) of the air intake unit (3);
an intake manifold (10) connected between the reconditioning chamber (4) and the engine (2); characterized in that,
an oxygen sensor (5) connected between the air intake unit (3) and the EMU
(6) configured for sensing at least one of oxygen content in atmosphere and mass
flow rate of intake air;
a control valve (7) communicatively connected to the EMU (6) for receiving control signals for activation;
an oxygen storage (8) configured for supplying oxygen to the reconditioning chamber (4) through an oxygen injector (9) upon activation of the control valve
(7) for maintaining air-fuel mixture in the engine (2).
6. The system as claimed in claim 5, wherein the EMU (6) generates control signals when at least one of sensed oxygen content in the atmosphere and mass flow rate of the intake air is less than pre-set threshold oxygen content and mass flow rate respectively, and depending on opening of engine valve and throttle input.
7. The system as claimed in claim 5, wherein the reconditioning chamber (4) is connected with a recirculation means (11) for supplying exhaust gas for drying the intake air.
8. The system as claimed in claim 5 is provided with a solenoid needle valve (12) for controlling amount of oxygen injection into the reconditioning chamber (4).
9. A method of maintaining ideal air-fuel mixture in an Engine and a system for maintaining air-fuel mixture in an Engine, are substantially as herein above described and as illustrated in accompanying drawings.