Claims:STATEMENT OF CLAIMS
We claim:
1. A system (100, 200) for controlling exhaust gas recirculation to an engine, said system (100) comprising:
a camshaft (102, 202);
a first valve (104, 204) adapted to be movably coupled to said camshaft (102, 202);
a second valve (106, 206) adapted to be movably coupled to said camshaft (102, 202); and
an electric motor,
wherein
said electric motor is adapted to rotate said camshaft (102, 202); and
said camshaft (102, 202) is adapted to move at least one of said first valve (104, 204) and said second valve (106, 206) to an open position.

2. The system (100) as claimed in claim 1, wherein said system (100) comprises a plurality of holding elements (107), where each of said holding element (107) is adapted to hold a bottom end (104b, 106b) of corresponding said valve (104, 106).

3. The system (100, 200) as claimed in claim 1, wherein said system (100, 200) comprises a plurality of rollers (108, 208), where each of said roller (108, 208) is coupled to corresponding valve (104, 106, 204, 206),
wherein
said each of said roller (108, 208) is movably connected to said camshaft (102, 202) to facilitate a movement of corresponding said valve (104, 106, 204, 206).

4. The system (100) as claimed in claim 3, wherein said camshaft (102) includes a cam (102C) adapted to be movably connected to said plurality of rollers (108).

5. The system (200) as claimed in claim 4, wherein said camshaft (202) includes a plurality of cams (202C), where each of said cam (202C) is adapted to be movably engaged with corresponding each of said roller (208).

6. The system (100, 200) as claimed in claim 1, wherein said system (100, 200) comprises a plurality of springs (110, 210), where each of said spring (110, 210) is adapted to retain corresponding said valve (104, 204, 106, 206) in a closed position.

7. The system (100, 200) as claimed in claim 6, wherein said system (100, 200) comprises a plurality of spring retainers (109, 209), where each of said spring retainer (109, 209) is adapted to connected to corresponding said valve (104, 106, 204, 206) to retain corresponding each of said spring (110, 210).

8. The system (100, 200) as claimed in claim 1, wherein said first valve (104, 204) in the open position is adapted to allow the hot exhaust gas flow directly to an air intake system of the engine through a bypass passage (10B) of an EGR housing (10), bypassing an EGR cooler (C).

9. The system (100, 200) as claimed in claim 8, wherein said second valve (104, 204) in the open position is adapted to allow the hot exhaust gas flow to the EGR cooler (C) through an EGR cooler passage (10C) of the EGR housing (10).

10. The system (100, 200) as claimed in claim 1, wherein said system (100, 200) comprises a controller unit adapted to actuate said electric motor.

11. The system (100) as claimed in claim 1, wherein said first valve (104) and said second valve (106) are at an angular position with respect to said camshaft (102); and said first valve (104) and said second valve (106) are offset with respect to said camshaft (102).

12. The system (200) as claimed in claim 1, wherein said first valve (204) and said second valve (206) are perpendicular to said camshaft (202).

13. A method (300) for controlling exhaust gas recirculation to an engine, said method (300) comprising:
rotating a camshaft (102, 202) through an electric motor; and
allowing hot exhaust gas flow to the engine through a bypass passage (10B) of an EGR housing (10), bypassing an EGR cooler (C), by moving a first valve (104, 204) to an open position through the camshaft (102, 202); and
allowing hot exhaust gas flow to the EGR cooler (C) through an EGR cooler passage (10C) of the EGR housing (10) by moving a second valve (106, 206) to an open position through the camshaft (102, 202).

14. The method (300) as claimed in claim 13, wherein said method (300) comprises allowing the cooled exhaust gas flow from the EGR cooler (C) to the engine.

15. The method (300) as claimed in claim 13, wherein said method (300) comprises actuating the electric motor through a controller unit prior to said rotating the camshaft (102, 202) through the electric motor.

16. An EGR housing (10) comprising:
an EGR cooler passage (10C) adapted to be provided in fluid communication with an EGR cooler (C);
a bypass passage (10B) adapted to allow hot exhaust gas flow directly to an engine, bypassing the EGR cooler (C); and
a partition (10W) provided in between said passages (10C, 10B) to separate said bypass passage (10B) from said EGR cooler passage (10C).
, Description:TECHNICAL FIELD
[001] The embodiments herein generally relate to engines and more particularly, to systems and methods for controlling exhaust gas re-circulation to engine.

BACKGROUND
[002] During the operation of an internal combustion engine, certain pollutants are emitted out in the exhaust gases. These gases generally consist of oxides of nitrogen (NOx), carbon monoxide (CO) and un-burnt particulate matter (PM). Emission of such pollutants is majorly based on the operating conditions of the engine and the power output of the engine. Due to the harmful nature of these pollutants, the government regulatory bodies have emission norms, which all the engines have to be complying to.
[003] Exhaust gas re-circulation (EGR) is a technique commonly used for controlling the generation of undesirable pollutant gases during the operation of internal combustion engines. This technique has proven particularly useful in internal combustion engines used in motor vehicles such as passenger cars, light duty trucks, and other on-road motor vehicles. The exhaust gas re-circulation technique primarily involves the re-circulation of exhaust gas by-products into the intake air supply to the internal combustion engine. This exhaust gas thus reintroduced in to the engine cylinder reduces the concentration of oxygen therein, which in turn lowers the maximum combustion temperature within the engine cylinder and slows the chemical reaction of the combustion process thereby decreasing the formation of nitrous oxide. Furthermore, the exhaust gases typically contain a portion of unburned hydrocarbon which is burned on its reintroduction into the engine cylinder, which further reduces the emission of exhaust gas by-products which would be emitted as undesirable pollutants from the internal combustion engine. Therefore, it is required to control the quantities of exhaust gas in exhaust gas recirculation system to reduce NOx emission with proper combustion.
[004] The hot exhaust gas from the engine is required be cooled before mixing with the fresh air and re-circulated into the engine cylinder for combustion. The cooled exhaust gas can reduce the temperature in engine cylinder during combustion thereby reducing the NOx formation. Sometimes, hot exhaust gases are required to be re-circulated to the engine during cold start conditions and regeneration of particulate filter. Further, the amount of exhaust gas recirculation required during combustion varies with amount of fuel injected into the engine cylinder and the speed of the engine. Conventional EGR system includes an electric motor operated EGR valve to control the amount of exhaust gas re-circulation to engine and a vacuum operated bypass flap to switch between the hot EGR (exhaust gas bypassed EGR cooler) and cold EGR (exhaust gas passed through the EGR cooler) to the engine. Separate mechanisms for operating the EGR valve and the bypass flap incur high costs. Providing the EGR valve and the bypass flap to the EGR housing and coupling operating mechanisms to the EGR valve and the bypass flap increases an overall size of the EGR housing which in turn consumes more packaging space. Further, the vacuum operated flap mechanism requires a vacuum tube connected from a vacuum pump and a vacuum switching valve for operating the bypass flap. Any leakage in the vacuum tube, vacuum pump and the vacuum switching valve would affect the proper functioning of the vacuum operated flap mechanism. Further, the bypass flap is subjected to higher leakage rate of the exhaust gas between the cold and hot EGR passages in the EGR housing.
[005] Therefore, there exists a need for systems and methods for controlling exhaust gas recirculation (hot and/or cold EGR) to engine, which obviates the aforementioned drawbacks.

OBJECTS

[006] The principal object of embodiments herein is to provide systems for controlling exhaust gas recirculation (EGR), hot and/or cold EGR) to engine.
[007] Another object of embodiments herein is to provide methods for controlling exhaust gas recirculation to engine.
[008] Another object of embodiments herein is to provide systems for controlling exhaust gas recirculation to engine, which is precise, reliable and durable.
[009] Another object of embodiments herein is to provide systems for controlling exhaust gas recirculation to engine, which reduces the leakage rate of exhaust gas between the hot and cold EGR passages in EGR housing.
[0010] Another object of embodiments herein is to provide systems for controlling exhaust gas recirculation to engine, which provides a single common electric motor to actuate a cool EGR valve and a hot EGR valve (bypass valve).
[0011] Another object of embodiments herein is to provide systems for controlling exhaust gas recirculation to engine, which reduces NOx emissions from the engine.
[0012] Another object of embodiments herein is to provide systems for re-circulating exhaust gas to the engine, which improves fuel economy of a vehicle.
[0013] Another object of embodiments herein is to provide a system for re-circulating exhaust gas to the engine, which eliminates a separate vacuum operated flap mechanism and a bypass flap thereby increasing the durability of the EGR system.
[0014] Another object of embodiments herein is to provide a compact EGR housing.
[0015] Another object of embodiments herein is to provide an EGR housing, which provides a separate passage for hot EGR flow directly to engine and a separate passage for EGR flow to an EGR cooler.
[0016] These and other objects of embodiments herein will be better appreciated and understood when considered in conjunction with following description and accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[0017] The embodiments are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0018] Fig. 1 depicts a side view of a system for controlling exhaust gas re-circulation to an engine, according to first embodiments as disclosed herein;
[0019] Fig. 2a depicts a cross-sectional view of an EGR (exhaust gas recirculation) housing in which a first valve (hot EGR valve) is in an open position to allow hot exhaust gas flow directly to the engine, bypassing an EGR cooler, according to the first embodiments as disclosed herein;
[0020] Fig. 2b depicts a cross-sectional view of the EGR housing in which a second valve (cold EGR valve) is in an open position to allow the hot exhaust gas flow to the EGR cooler to cool the exhaust gas, according to the first embodiments as disclosed herein;
[0021] Fig. 3 depicts a side view of a system for controlling exhaust gas re-circulation to an engine, according to second embodiments as disclosed herein;
[0022] Fig. 4a depicts a cross-sectional view of a EGR housing in which a first valve (hot EGR valve) is in an open position to allow the hot exhaust gas flow directly to the engine, bypassing an EGR cooler, according to second embodiments as disclosed herein;
[0023] Fig. 4b depicts a cross-sectional view of the EGR housing in which a second valve (cold EGR valve) is in an open position to allow the hot exhaust gas flow to the EGR cooler to cool the exhaust gas, according to second embodiments as disclosed herein.
[0024] Fig. 5a depicts a cross sectional view of the EGR housing, the EGR cooler, the first valve and the second valve in assembled condition, where hot exhaust gas flow from the first valve to the engine through a bypass passage of the EGR housing, according to the first and second embodiments as disclosed herein;
[0025] Fig. 5b depicts a cross-sectional view of the EGR housing, the EGR cooler, the first valve and the second valve in assembled condition, where hot exhaust gas flow from the second valve to the EGR cooler through an EGR cooler passage of the EGR housing, according to the first and second embodiments as disclosed herein; and
[0026] Fig. 6 depicts a flowchart indicating a method for controlling exhaust gas re-circulation to the engine, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0027] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0028] The embodiments herein achieve systems and methods for controlling exhaust gas recirculation (hot and/or cold EGR) to engine. Another embodiment herein achieve systems for controlling exhaust gas recirculation to engine, which is precise, reliable and durable and reduces the leakage rate of exhaust gas between the hot and cold EGR passages in EGR housing and reduces NOx emissions from the engine. Referring now to the drawings Figs 1 through 6, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0029] Fig. 1 depicts a side view of a system (100) for controlling exhaust gas re-circulation to an engine, according to embodiments as disclosed herein. The system (100) is adapted to control the amount of exhaust gas re-circulation (hot and/or cold EGR) to the engine to reduce oxides of nitrogen (NOx) emissions from the engine. In the first embodiment, the system (100) includes a camshaft (102), a first valve (104), a second valve (106), a plurality of holding elements (107), a plurality of rollers (108), a plurality of spring retainers (109), a plurality of springs (110), an electric motor (not shown) and a controller unit (not shown).
[0030] The camshaft (102) is adapted to move at least one of the first valve (104) and the second valve (106) when the camshaft (102) is being rotated by the electric motor (not shown). In the first embodiment, the camshaft (102) includes a cam (102C), as shown in fig. 1 to fig. 2b) adapted to be movably engaged with the plurality of rollers (108). The cam (102C) is adapted to move at least one of the first valve (104) and the second valve (106) when the camshaft (102) is rotated by the electric motor (not shown).
[0031] The first valve (104) is adapted to control the hot exhaust gas (G), as shown in fig. 2a) flow to the engine by allowing the exhaust gas (G) flow from an exhaust gas recirculation pipe (10P), hereinafter called as EGR pipe, as shown in fig. 5a) to a bypass passage (10B), as shown in fig. 5a and fig. 2a) of an exhaust gas recirculation housing (10), hereinafter called as EGR housing, as shown in fig 2a and fig. 5a) when the first valve (104) is being moved by the electric motor (not shown) through the camshaft (102). The first valve (104) is also called as hot EGR valve. The first valve (104) is adapted to be movably coupled to the camshaft (102) through corresponding holding element (107) and corresponding roller (108). The first valve (104) is movable between an open position and a closed position. The first valve (104) in the open position (as shown in fig. 2a and fig. 5a) is adapted allow the hot exhaust gas flow from the EGR pipe (10P) to an air intake system (not shown) of the engine through the bypass passage (10B) of the EGR housing (10), bypassing an exhaust gas recirculation cooler (C), hereinafter called as EGR cooler, as shown in fig. 5a). The first valve (104) in the closed position (as shown in fig. 2b and fig. 5b) is adapted to restrict exhaust gas flow from the EGR pipe (10P) to the bypass passage (10B) of the EGR housing (10). For the purpose of this description and ease of understanding, the first valve (104) is considered to be a poppet valve. However, it is also within the scope of this invention to provide any other type of valves for controlling hot exhaust gas flow to the engine without otherwise deterring the intended function of the first valve (104) as can be deduced from the description and corresponding drawings.
[0032] The second valve (106) is adapted to control the hot exhaust gas (G), as shown in fig. 2b and fig. 5b) flow to the EGR cooler (C) by allowing the exhaust gas flow to an exhaust gas recirculation passage (10C), hereinafter called as EGR cooler passage, as shown in fig. 2b and fig. 5b) of the EGR housing (10) therein to control cool exhaust gas flow to the engine when the second valve (106) is being moved by the electric motor (not shown) through the camshaft (102). The second valve (106) is also called as cold EGR valve. The second valve (106) is adapted to be movably coupled to the camshaft (102) through corresponding another holding element (107) and another roller (108). The second valve (106) is movable between an open position and a closed position. The second valve (106) in the open position (as shown in fig. 2b and fig. 5b) is adapted to allow the hot exhaust gas flow from the EGR pipe (10P) to the EGR cooler (C) through the EGR cooler passage (10C) of the EGR housing (10), as shown in fig. 2b and fig. 5b) to cool the exhaust gas and the cooled exhaust gas from the EGR cooler (C) flows to the intake system (not shown) of the engine. The second valve (106) in the closed position (as shown in fig. 2a and fig. 5a) is adapted to restrict the exhaust gas flow from the EGR pipe (10P) to the EGR cooler passage (10C) of the EGR housing (10). For the purpose of this description and ease of understanding, the second valve (106) is considered to be a poppet valve. However, it is also within the scope of this invention to provide any other type of valves for controlling cold exhaust gas flow to the engine through the EGR cooler (C) without otherwise deterring the intended function of the second valve (106) as can be deduced from the description and corresponding drawings. In the first embodiment, the first valve (104) and the second valve (106) are angularly positioned with respect to the camshaft (102). The first valve (104) and the second valve (106) are offset with respect to the camshaft (102). The first valve (104) and the second valve (106) is at a predefined angle with respect to the camshaft (102).
[0033] One holding element (107) is adapted to hold a bottom end (104b), as shown in fig. 1) of the first valve (104). Another holding element (107) is adapted to hold a bottom end (106b), as shown in fig. 1) of the second valve (106).
[0034] Each roller (108) is adapted to be connected to corresponding valve (104, 106) through corresponding each holding element (107). Each roller (108) is movably engaged with the single cam (102C) of the camshaft (102). Each roller (108) is adapted to facilitate a movement of corresponding valve (104, 106) when corresponding roller (108) is moved by the cam (102C) on rotation of the camshaft (102).
[0035] Each spring retainer (109) is adapted to retain corresponding each spring (110). Each spring retainer (109) is adapted to be connected to corresponding valve (104, 106) thereby retaining corresponding each spring (110). Each spring retainer (109) is disposed above corresponding each holding element (107). Each spring (110) is adapted to retain corresponding valve (104, 106) in the closed position. Each spring (110) is loaded between corresponding outer portion of the EGR housing (10) and corresponding each spring retainer (109).
[0036] The electric motor (not shown) is adapted to rotate the camshaft (102) to move at least one of the first valve (104) and the second valve (106) between at least one of the open position and the closed position based on the information from the controller unit (not shown). For example, the electric motor (not shown) rotates the camshaft (102) in an anti-clockwise direction (as shown in fig. 2a) therein to move the first valve (104) to the open position. The second valve (106) remains in the closed position when the first valve (104) is in the open position, as shown in fig. 2a). Similarly, the electric motor (not shown) rotates the camshaft (102) in a clockwise direction therein (as shown in fig. 2b) to move the second valve (106) to the open position. The first valve (104) remains in the closed position when the second valve (106) is in the open position (as shown in fig. 2b).
[0037] The controller unit (not shown) determines the amount of EGR required for the engine mainly based on speed of the engine and fuel injected into engine cylinder(s). It is also within the scope of this invention to provide the controller unit (not shown) to consider any other operating parameters of the engine and/or any other parameters for determining the amount of EGR required for the engine. The controller unit (not shown) is adapted to actuate the electric motor (not shown) therein to move at least one of the first valve (104) and the second valve (106) to the open position to allow calculated amount of exhaust gas (hot or cold exhaust gas) to the engine. The controller unit (not shown) is an electronic controller unit.
[0038] Fig. 3 depicts a side view of a system (200) for controlling exhaust gas re-circulation to an engine, according to second embodiments as disclosed herein. The system (200) is adapted to control the amount of exhaust gas re-circulation (hot and/or cold EGR) to the engine to reduce oxides of nitrogen (NOx) emissions from the engine. In the second embodiment, the system (200) includes a camshaft (202), a first valve (204), a second valve (206), a plurality of rollers (208), a plurality of spring retainers (209), a plurality of springs (210), an electric motor (not shown) and a controller unit (not shown).
[0039] The camshaft (202) is adapted to move at least one of the first valve (204) and the second valve (206) when the camshaft (202) is being rotated by the electric motor (not shown). In the second embodiment, the camshaft (202) includes a plurality of cams (202C), as shown in fig. 3 to fig. 4b), where each cam (202C) is adapted to be movably engaged with corresponding each roller (208). Each cam (202C) is adapted to move corresponding each valve (204, 206) when the camshaft (202) is rotated by the electric motor (not shown).
[0040] The first valve (204) is adapted to control the hot exhaust gas (G, as shown in fig. 4a and fig. 5a) flow to the engine by allowing the exhaust gas (G) flow from an exhaust gas recirculation pipe (10P), hereinafter called as EGR pipe, as shown in fig. 5a) to a bypass passage (10B), as shown in fig. 5a) of an exhaust gas recirculation housing (10), hereinafter called as EGR housing, as shown in fig 4a and fig. 5a) when the first valve (204) is being moved by the electric motor (not shown) through the camshaft (202). The first valve (204) is also called as hot EGR valve. The first valve (204) is movable between an open position and a closed position. The first valve (204) in the open position (as shown in fig. 4a and fig. 5a) is adapted to allow the hot exhaust gas flow from the EGR pipe (10P), as shown in fig. 5a) to an air intake system (not shown) of the engine through the bypass passage (10B) of the EGR housing (10), bypassing an exhaust gas recirculation cooler (C), hereinafter called as EGR cooler, as shown in fig. 5a). The first valve (204) in the closed position (as shown in fig. 4b and fig. 5b) is adapted to restrict exhaust gas flow from the EGR pipe (10P) to the bypass passage (10B) of the EGR housing (10). In the second embodiment, the first valve (204) and the second valve (206) is perpendicular to the camshaft (202). For the purpose of this description and ease of understanding, the first valve (204) is considered to be a poppet valve. However, it is also within the scope of this invention to provide any other type of valves for controlling hot exhaust gas flow to the engine without otherwise deterring the intended function of the first valve (204) as can be deduced from the description and corresponding drawings
[0041] The second valve (206) is adapted to control the hot exhaust gas flow to the EGR cooler (C) by allowing the exhaust gas flow to an exhaust gas recirculation passage (10C), hereinafter called as EGR cooler passage, as shown in fig. 4b and fig. 5b) of the EGR housing (10) therein to control cool exhaust gas flow to the to the intake system (not shown) of the engine when the second valve (206) is being moved by the electric motor (not shown) through the camshaft (202). The second valve (206) is also called as cold EGR valve. The second valve (206) is movable between an open position and a closed position. The second valve (206) in the open position (as shown in fig. 4b and fig. 5b) is adapted to allow the hot exhaust gas flow from the EGR pipe (10P) to the EGR cooler (C) through the EGR cooler passage (10C) of the EGR housing (10), as shown in fig. fig.4b and fig. 5b) to cool the exhaust gas and the cooled exhaust gas from the EGR cooler (C) flows to the intake system of the engine. The second valve (206) in the closed position (as shown in fig. 4a and fig. 5a) is adapted to restrict the exhaust gas flow from the EGR pipe (10P) to the EGR cooler passage (10C) of the EGR housing (10). For the purpose of this description and ease of understanding, the second valve (206) is considered to be a poppet valve. However, it is also within the scope of this invention to provide any other type of valves for controlling cold EGR flow to the engine through the EGR cooler (C) without otherwise deterring the intended function of the second valve (106) as can be deduced from the description and corresponding drawings
[0042] In the second embodiment, each roller (208) is directly connected to corresponding valve (204, 206). Each roller (208) is movably engaged with corresponding each cam (202C) of the camshaft (202). Each roller (208) is adapted to facilitate a movement of corresponding valve (204, 206) when corresponding roller (208) is moved by corresponding each cam (202C) on rotation of the camshaft (202).
[0043] Each spring retainer (209) is adapted to retain corresponding each spring (210). Each spring retainer (209) is adapted to be connected to corresponding valve (204, 206) thereby retaining corresponding each spring (210). Each spring (210) is adapted to retain corresponding valve (204, 206) in the closed position. Each spring (210) is loaded between corresponding outer portion of the EGR housing (10) and corresponding each spring retainer (209).
[0044] The electric motor (not shown) is adapted to rotate the camshaft (202) to move at least one of the first valve (204) and the second valve (206) between at least one of the open position and the closed position based on the information from the controller unit (not shown). For example, the electric motor (not shown) rotates the camshaft (202) in an anti-clockwise direction (as shown in fig. 4a) therein to move the first valve (204) to the open position. The second valve (206) remains in the closed position when the first valve (204) is in the open position, as shown in fig. 4a). Similarly, the electric motor (not shown) rotates the camshaft (202) in a clockwise direction (as shown in fig. 4b) therein to move the second valve (206) to the open position. The first valve (204) remains in the closed position when the second valve (206) is in the open position, as shown in fig. 4b).
[0045] The controller unit (not shown) determines the amount of EGR required for the engine mainly based on speed of the engine and fuel injected into engine cylinder(s). It is also within the scope of this invention to provide the controller unit (not shown) to consider any other operating parameters of the engine and/or any other parameters for determining the amount of EGR required for the engine. The controller unit (not shown) is adapted to actuate the electric motor (not shown) therein to move at least one of the first valve (204) and the second valve (206) to the open position to allow calculated amount of exhaust gas (hot or cold exhaust gas) to the engine.
[0046] The EGR housing (10) includes an EGR cooler passage (10C), a bypass passage (10B) and a partition (10W), as shown in fig. 5a). The EGR cooler passage (10C) is adapted to be provided in fluid communication with the EGR cooler (10C). The EGR cooler passage (10C) is adapted to direct the exhaust gas flow from the second valve (106, 206) to the EGR cooler (C). The bypass passage (10B) is adapted to direct the hot exhaust gas flow from the first valve (104, 204) to the engine. The partition (10W) is in between the bypass passage (10B) from the EGR cooler passage (10C) to separate the bypass passage (10B) from the EGR cooler passage (10C).
[0047] Fig. 6 depicts a flowchart indicating a method (300) for controlling exhaust gas re-circulation to the engine, according to embodiments as disclosed herein. In an embodiment, the method (300) includes, rotating a camshaft (102, 202) through an electric motor, step (302), allowing hot exhaust gas flow to the engine through a bypass passage (10B) of an EGR housing (10), bypassing an EGR cooler (C), by moving a first valve (104, 204) to an open position through the camshaft (102, 202), step (304) and allowing hot exhaust gas flow to the EGR cooler (10C) through an EGR cooler passage (10C) of the EGR housing (10) by moving a second valve (106, 206) to an open position through the camshaft (102, 202), step (306).
[0048] Further, the method (300) includes, allowing the cooled exhaust gas flow from the EGR cooler (10C) to the engine, step (308).
[0049] The method (300) includes, actuating the electric motor (not shown) through a controller unit, step (301).
[0050] Therefore, systems (100, 200) and method (300) for controlling exhaust gas recirculation to engine to reduce NOx emission from the engine are provided.
[0051] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the spirit and scope of the embodiments as described herein.