Claims:
1. A system for controlling the emissions of an internal combustion engine (100), the system comprising:
a fuel injection pump (110) having a throttle position lever (112) integrated with a throttle position sensor (114);
an exhaust gas recirculation (EGR) valve for directing exhaust gases from an exhaust manifold of the internal combustion engine (100) to an intake manifold of the internal combustion engine (100); and
a microcontroller connected with the throttle position sensor (114) and the EGR valve, the microcontroller is configured to compare the real-time speed of the internal combustion engine (100) with respect to the pre-stored engine torque map data and adjust the position of the EGR valve in order to control the emission of the internal combustion engine (100).

2. The system for controlling the emissions of an internal combustion engine (100) as claimed in claim 1, wherein the microcontroller has a memory to store the engine torque map data with respect to the torque of the internal combustion engine (100).

3. The system for controlling the emissions of an internal combustion engine (100) as claimed in claim 1, wherein the Exhaust Gas Recirculation (EGR)includes a direct current (DC) motor to actuate the EGR valve.

4. The system for controlling the emissions of an internal combustion engine (100)as claimed in claim 1, wherein the EGR comprises a feedback sensor to obtain the real-time position of the Exhaust Gas Recirculation (EGR) valve.

5. The system for controlling the emissions of an internal combustion engine (100) as claimed in claim 1, wherein the fuel injection pump includes a lever bracket connected with the throttle lever (112) to adapt the throttle position sensor (114) with the throttle lever (112).

6. The system for controlling the emissions of an internal combustion engine (100) as claimed in claim 6, wherein the throttle position sensor (114) is adapted with the throttle lever (112) via. a fastening mechanism.

7. An Exhaust Gas Recirculation (EGR) method of an internal combustion engine for controlling emissions in exhaust gas, the method comprising:
obtaining a real time speed of the internal combustion engine(100);
comparing, by a microcontroller, the real-time speed of the internal combustion engine (100) with a pre-stored engine torque mapdata; and
adjusting, by the microcontroller, a position of an EGR valve based on the aforesaid comparison, thereby controlling the emission of the internal combustion engine.

8. The method as claimed in claim 7, wherein the step of adjusting the position of the EGR valve is performed by actuating a dc motor connected with the EGR valve.
, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)

&

THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[See section 10, Rule 13]
A SYSTEM AND METHOD FOR CONTROLLING THE EMISSIONS OF AN INTERNAL COMBUSTION ENGINE

MAHINDRA & MAHINDRA LIMITED, A COMPANY REGISTERED UNDER THE INDIAN COMPANIES ACT, 1913, HAVING ADDRESS AT MAHINDRA RESEARCH VALLEY (MRV), MAHINDRA WORLD CITY, PLOT NO: 41/1, ANJUR P.O., CHENGALPATTU – 603004, KANCHEEPURAM DIST., TAMIL NADU, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
FIELD OF THE INVENTION:
The present invention relates to a system and method for controlling the emissions of an internal combustion engine and more particularly to controlling the exhaust gas recirculation of the internal combustion engine.
BACKGROUND OF THE INVENTION
Exhaust gas recirculation is used in internal combustion engine for controlling the generation of undesirable pollutant gases and particulate matter produced during the operation of the combustion in the internal combustion engines. The exhaust gas recirculation (EGR) process primarily involves the recirculation of exhaust gas by-products into the intake air supply of the internal combustion engine whereas the exhaust gas is reintroduced to the engine cylinder to reduce the concentration of oxygen therein, which in turn lowers the maximum combustion temperature within the cylinder and lowers the chemical reaction of the combustion process, reducing the formation of nitrous oxide.

Further, it is known that the oxides of nitrogen are formed in higher volume in the event of combustion temperature approaching adiabatic flame temperature. The EGR system reduces the Nitrogen Oxide emissions by circulating the small amount of exhaust gases into the intake manifold to mix with the incoming air/ fuel mixture.

It is widely known that the amount of EGR flow depends upon the engine operating conditions such as combustion temperature, engine speed, throttle position etc. A higher EGR flow is an essential requirement during cruising and mid-range acceleration wherein the combustion temperatures are typically very high, whereas, a low EGR flow is required during low speed and light-weight load conditions. Furthermore, no EGR flow is required occur during engine warm up, idle and full throttle conditions.

It is known to operate the EGR valve in accordance with the subjected engine conditions, the Electronic control unit of the internal combustion engine is configured to control or actuate the EGR valve for recirculation of the exhaust gas in accordance with the predetermined EGR mapping with respect to the throttle position and engine speed of the vehicle. It has been observed that controlling the EGR valve position by the signal received from the Throttle Position sensor based upon the mapping of EGR is difficult and further it does not result into obtainment of desired reduction of the NOx emissions.

Furthermore, it has also been observed that the TPS signal from actuation of FIP throttle lever was narrow and the direct control of EGR map from this input is challengeable or ineffective in terms of providing a fine control of EGR position consequently affecting the efficiency of the internal combustion engine.
Therefore, the object of the present invention is to solve one or more of the aforesaid issue.
SUMMARY OF THE INVENTION
The present invention provides an exhaust gas recirculation system for controlling the emissions of an internal combustion engine, the system comprising: a fuel injection pump having a throttle lever integrated with a throttle position sensor. The system comprises an Exhaust Gas Recirculation (EGR) valve for directing exhaust gases from an exhaust manifold of the internal combustion engine to an intake manifold of the internal combustion engine and a microcontroller connected with the throttle position sensor and the Exhaust Gas Recirculation (EGR) valve. The microcontroller is configured to compare the real-time speed of the internal combustion engine with respect to the pre-stored engine torque map data and adjust the position of the EGR valve in order to reduce the emissions.

In accordance with the present invention, the micro-controller has a memory to store the data with respect to the torque of the internal combustion engine. The Exhaust Gas Recirculation (EGR) comprises a direct current (DC) motor to actuate the EGR valve. The system comprises an Exhaust Gas Recirculation (EGR) valve position sensor to obtain the real-time position of the Exhaust Gas Recirculation (EGR) valve.

In accordance with the present invention, the throttle position lever comprises a lever bracket fixed to adapt the throttle position sensor along with the throttle lever of the fuel injection pump via. a fastening mechanism. The EGR system controls NOx emissions by controlling the amounts of exhaust gases into the intake manifold.

In accordance with the present invention, an Exhaust Gas Recirculation (EGR) method of an internal combustion engine for controlling emissions in exhaust gas is provided. The method comprising the steps of: obtaining a real time speed of the internal combustion engine; comparing, by a microcontroller, a real-time speed of the internal combustion engine with a pre-stored torque map data; and adjusting, by the microcontroller, a position of an EGR valve based on the aforesaid comparison, thereby controlling the emissions of internal combustion engine.

BRIEF DESCRIPTION OF THE DRAWINGS
Reference will be made to embodiments of the invention which may be illustrated in the accompanying figure(s). These figure(s) are intended to be illustrative and not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.

FIGURE 1 illustrates the block diagram of the exhaust gas recirculation system for controlling the emissions of an internal combustion engine in accordance with an embodiment of the present invention.

FIGURE 2 illustrates the integrated assembly of the Throttle Position Lever of the Fuel Injection Pump and the Throttle Position sensor.

FIGURE 3 shows the method steps for controlling the emissions of an internal combustion engine in accordance with an embodiment of the present invention.

FIGURE 4 shows a comparison graph and the test results for the emissions test conducted between the conventional system and the system of the present invention transmissions in accordance with a working experiment.

DETAILED DESCRIPTION OF THE INVENTION
The subject matter is now described with reference to the drawings. In the following description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of the claimed subject matter. It may be evident; however, that such matter can be practiced with these specific details. In other instances, well-known structures as shown in diagram form in order to facilitate describing the invention.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

The present invention provides a technical solution to the problems related with the conventional TPS based Exhaust Gas Recirculation(EGR) system. The present system provides a torque based Exhaust Gas Recirculation system provides an integrated Throttle position lever with Throttle position sensor (TPS). Throttle position sensor (TPS) is connected with a microcontroller which is configured to compare the real-time speed of the engine with respect to a predetermined engine torque map data. After mapping the torque, the microcontroller operates the EGR valve to re-circulate the exhaust gas into the intake manifold of the internal combustion engine to reduce the NOx emissions.

Referring to the FIGURE 1 of the drawings, a system for controlling the emissions of an internal combustion diesel engine is provided in accordance with an embodiment of the present invention. The system comprises a fuel injection pump (110) having a throttle lever (112)which is integrated with a throttle position sensor (114). The throttle lever (112) controls the Fuel Injection pump in accordance with depressed acceleration lever by a user driver. The system comprises an EGR valve for directing exhaust gases from an exhaust manifold of the internal combustion engine to an intake manifold of the internal combustion engine. The system includes a microcontroller connected with the throttle position sensor (114) and the EGR valve. The microcontroller is configured to compare the real-time speed of the internal combustion engine with respect to a pre-stored engine torque map data. The EGR comprises a feedback position sensor to obtain the real-time position of the EGR valve.

In accordance with the present invention, the microcontroller is configured to control or actuate the EGR valve for recirculation of the exhaust gas whereas the engine torque mapping is conducted in accordance with the torque of the internal combustion engine. The predetermined engine torque mapping with respect to the real time speed of the engine enables the microcontroller to adjust the position of the EGR valve precisely and effectively in order to reduce the emissions effectively in comparison to the TPS based EGR mapping of the conventional EGR system.

In accordance with an embodiment of the present invention, the EGR comprises a direct current (DC) motor to actuate the EGR valve. The microcontroller is configured to provide torque based EGR map control. After EGR mapping the input signal is feed to actuate the EGR valve such that the demanded position of the throttle lever by the driver is met by EGR valve wherein the EGR system reduces NOx emissions by controlling the amounts of exhaust gases into the intake manifold.

Referring to FIGURE 3, in accordance with an embodiment of the present invention, a method for operating an Exhaust Gas Recirculation of an internal combustion to control the emissions in the exhaust gas is provided. The method comprising the steps of: obtaining a real time speed of the internal combustion engine, comparing, by a microcontroller, the real-time speed of the internal combustion engine with a pre-stored torque map data; and adjusting, by the microcontroller, a position of an EGR valve based on the aforesaid comparison, thereby controlling the emission of the internal combustion engine. The position of the EGR valve is adjusted by actuating a dc motor connected with the EGR valve.

FIGURE 2 shows the assembly of an internal combustion engine having a fuel injection pump (FIP). The fuel injection pump is having an integrated assembly of throttle lever (112) and the throttle position sensor (114). The internal combustion diesel engine (100) comprises a fuel injection pump (110) for injecting the fuel into the combustion chamber. The fuel injection pump (110) is having a throttle lever (112) which is fixed in the fuel injection pump (110) with an internal spring arrangement. The fuel injection pump (110) includes a lever bracket connected with the throttle lever (112)to adapt the throttle position sensor (114) with the throttle lever (112)via. a fastening mechanism. In the present embodiment, the fastening mechanism is a screw. The throttle position sensor (114) is adapted in the throttle lever (112) of the fuel injection pump (110) and its position is moved with respect to the user driver demand. The integrated throttle position sensor (114) and the throttle lever (112) assembly provide a better control over the Fuel Injection pump (110) in accordance with requirements of the user driver.

Example 1:
FIGURE 4 shows a comparison graph and the test results for the emissions test conducted between the conventional system and the system of the present invention transmissions in accordance with a working experiment. A naturally aspirated inline 3.53L - 4 Cylinder Engine having a torque based Progressive EGR was tested for Non-Road Transient Cycle in comparison with a conventional TPS based EGR system.

It was observed that at the time of conducting Test 1 the NOx emission produced by the present system was 3.69 whereas the NOx emissions of the conventional EGR system was 4.02. Under test 2 of the experiment, the NOx emission produced by the present system was found to be 3.71 whereas the NOx emission of the conventional EGR system was 3.77. Hence, the present torque based EGR system was found successful over conventional TPS based EGR system.

Advantages of the present invention
The present invention has the following technical advantages:
1. The system of the present invention provides a fine control over the EGR to reduce the NOx emissions.
2. The system of the present invention improves the transient engine operating performance with higher regeneration interval.
3. The present invention provides a cost-effective solution and better control.

The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.