Claims:We claim:
1. An internal combustion engine (10), said internal combustion engine (10) comprising:
an engine block (12) comprising an inlet valve (14) and an exhaust valve (16), said inlet valve (14) and said exhaust valve (16) adapted to be operated during a suction stroke of said internal combustion engine (10);
an air flow path (18) in flow communication between an inlet (20) of said engine block (12) and an outlet (22) of said engine block (12), said air flow path (18) adapted to channel air to the engine cylinders via said exhaust valve (16) during the suction stroke of said internal combustion engine (10); and
a first valve (24) located in said air flow path (18), said first valve (24) adapted to control the flow of air to said exhaust valve (16) during the suction stroke of said internal combustion engine (10).

2. The internal combustion engine (10) in accordance with Claim 1 further comprising a second valve (26) coupled downstream from said outlet (22) of said engine block (12), said second valve (26) adapted to control the flow of exhaust gas during the exhaust stroke of said internal combustion engine (10).

3. The internal combustion engine (10) in accordance with Claims 1 and 2 wherein said first valve (24) and said second valve (26) are one selected from mechanically actuated valves and electrically actuated valves.

4. The internal combustion engine (10) in accordance with Claim 1 further comprising a first lobe (28) and a second lobe (30) defined on an exhaust cam (11), said first lobe (28) of said exhaust cam (11) adapted to open said exhaust valve (16) during a suction stroke of said internal combustion engine (10), said second lobe (30) of said exhaust cam (11) adapted to open said exhaust valve (16) during an exhaust stroke of said internal combustion engine (10).

5. The internal combustion engine (10) in accordance with Claim 4 wherein an angle between said first lobe (28) and said second lobe (30) is proportional to opening positions of said exhaust cam (11) between the suction stroke and the exhaust stroke of said internal combustion engine (10).

6. A method of operating an internal combustion engine (10), said internal combustion engine (10) comprising:
an engine block (12) comprising an inlet valve (14) and an exhaust valve (16);
an air flow path (18) between an inlet (20) of said engine block (12) and an outlet (22) of said engine block (12), wherein said method comprises:
operating the inlet valve (14) and the exhaust valve (16) during a suction stroke of the internal combustion engine (10); and
channeling air to said exhaust valve (16) via said air flow path (18) during the suction stroke of the internal combustion engine (10).

7. An engine control unit, said engine control unit adapted to control operation of a valve (24), said valve (24) coupled to an air flow path (18) of an internal combustion engine, wherein said engine control unit is adapted to actuate said valve (24) to control the flow of air to an exhaust valve (16) of said internal combustion engine during a suction stroke of said internal combustion engine (10).

8. The engine control unit is accordance with Claim 7 wherein said valve (24) is an electrically actuated valve. , Description:Field of the invention:
[0001] This disclosure relates to an internal combustion engine, and more particularly to an apparatus for channeling air to an engine cylinder via an exhaust valve during a suction stroke of the internal combustion engine.
Background of the invention:
[0002] WO Patent Application Number 2006042785 describes a method that involves moving a piston axially, and opening one of the exhaust valves during a discharge stroke of an internal combustion engine. The exhaust valve opened during discharge stroke is closed before the piston reaches an upper dead point. One of the intake valves and the exhaust valve diagonally facing the opened intake valve are opened during suction stroke such that fresh air mixes with the exhaust gas. One of the intake valves and one of the exhaust valves diagonally facing the opened intake valve are opened during the suction stroke such that the fresh air mixes with the exhaust gas, thus increasing the cylinder charging, and hence requiring less throttling of the engine for achieving a pre-determined torque. The recycling of the exhaust gas improves the efficiency of the engine, reduces the fuel consumption, and lowers nitrogen oxide emissions

Brief description of the accompanying drawings:
[0003] An embodiment of the disclosure is described with reference to the following accompanying drawings:
[0004] Figure 1 illustrates an internal combustion engine in accordance with this disclosure with mechanically actuated valves.
[0005] Figure 2 illustrates an internal combustion engine in accordance with this disclosure with electrically actuated valves.
[0006] Figure 3 illustrates a cam used in combination with the internal combustion engine depicted in Figure 1.

Detailed description of the embodiments:
[0007] An internal combustion engine 10 is described. The internal combustion engine 10 comprises an engine block 12 comprising an inlet valve 14 and an exhaust valve 16, the inlet valve 14 and the exhaust valve 16 adapted to be operated during a suction stroke of the internal combustion engine 10. An air flow path 18 is in flow communication between an inlet 20 of the engine block 12 and an outlet 22 of the engine block 12, the air flow path 18 adapted to channel air to an engine cylinder via the exhaust valve 16 during the suction stroke of the internal combustion engine 10. A first valve 24 is coupled to the air flow path 18, the first valve 24 adapted to control the flow of air to the exhaust valve 16 during the suction stroke of the internal combustion engine 10.

[0008] In addition, a method of operating an internal combustion engine 10 is described. The comprises an engine block 12 comprising an inlet valve 14 and an exhaust valve 16. An air flow path 18 between an inlet 20 of the engine block 12 and an outlet 22 of the engine block 12 is provided. The method comprises operating the inlet valve 14 and the exhaust valve 16 during a suction stroke of the internal combustion engine 10. The method further comprises channeling air to the exhaust valve 16 via the air flow path 18 during the suction stroke of the internal combustion engine 10.
[0009] Moreover, an engine control unit is described. The engine control unit is adapted to control operation of a valve 24. The valve 24 is coupled to an air flow path 18 of an internal combustion engine, wherein the engine control unit is adapted to actuate the valve 24 to control the flow of air to an exhaust valve 16 of the internal combustion engine during a suction stroke of the internal combustion engine 10.
[00010] Figure 1 illustrates an internal combustion engine 10. The internal combustion engine 10 comprises an engine block 12. The engine block 12 comprises an inlet 20 and an outlet 22. An inlet valve 14 and an exhaust valve 16 are each coupled to the engine block 12. The inlet valve 14 is typically adapted to channel air from the inlet 20 into a cylinder of the engine block 12 during the suction stroke of the internal combustion engine 10. The exhaust valve 16 is typically adapted to channel exhaust gases from the cylinder of the engine block 12 to the outlet 22 during the exhaust stroke of the internal combustion engine 10.
[00011] An air flow path 18 is defined between the inlet 20 of the engine block 12 and the outlet 22 of the engine block 12. The air flow path 18 facilitates channeling air from the inlet 20 of the engine block 12 to the outlet 22 of the engine block 12. A first mechanically actuated valve 24 is coupled to the air flow path 18, and positioned proximate to the outlet 22 of the engine block 12. The first mechanically actuated valve 24 facilitates channeling air from the inlet 20 of the engine block 12 to the exhaust valve 16. The first mechanically actuated valve 24 is opened during the suction stroke of the internal combustion engine 10 to facilitate channeling air from the inlet 20 of the engine block 12 to the exhaust valve 16 via the first mechanically actuated valve 24. Air from the inlet 20 of the engine block 12 is channeled to the outlet valve 16 and into the engine cylinder via the mechanically actuated valve 24. During this time, a second mechanically actuated valve 26 that is in flow communication with an exhaust gas flow path remains closed. During the exhaust stroke of the internal combustion engine 10, the first mechanically actuated valve 24 is closed, while the second mechanically actuated valve 26 is opened. Therein, the exhaust gases from the engine cylinder is channeled to the exhaust gas path via the second mechanically actuated valve 26. In an alternate embodiment, the first mechanically actuated valve 24 and the second mechanically actuated valve 26 may be a first electronically actuated valve 24 and a second electronically actuated valve 26 respectively.
[00012] Figure 2 illustrates an internal combustion engine 10. An engine control unit (not shown) may be connected to a first electronically actuated valve 24 that is coupled to the air flow path 18, and positioned proximate to the outlet 22 of the engine block 12. The first electronically actuated valve 24 facilitates channeling air from the inlet 20 of the engine block 12 to the exhaust valve 16. More specifically, the first electronically actuated valve 24 is opened during the suction stroke of the internal combustion engine 10 by the engine control unit to facilitate channeling air from the inlet 20 of the engine block 12 to the exhaust valve 16 via the first electronically actuated valve 24. More specifically, air from the inlet 20 of the engine block 12 is channeled to the outlet valve 16 and into the engine cylinder via the first electronically actuated valve 24. During this time, a second electronically actuated valve 26 that is connected to the engine control unit and in flow communication with the exhaust gas flow path remains closed. During the exhaust stroke of the internal combustion engine 10, the first electronically actuated valve 24 is closed, while the second electronically actuated valve 26 is opened. Therein, the exhaust gases from the engine cylinder is channeled to the exhaust gas path via the second electronically actuated valve 26.
[00013] Figure 3 illustrates a cam 11 used in combination with the exhaust valve 16 of the internal combustion engine 10 depicted in Figure 1. The cam 11 includes a first lobe 28 and a second lobe 30. The first lobe 28 is used to open the exhaust valve 16 during the suction stroke of the internal combustion engine 10. The second lobe 30 is used to open the exhaust valve 16 during the exhaust stroke of the internal combustion engine 10. During the suction stroke of the internal combustion engine 10, the inlet valve 14 is opened. During this time, the first lobe 28 of the cam 11 opens the exhaust valve 16. While fresh air is channeled into the engine cylinder via the inlet valve 14, fresh air is also channeled into the engine cylinder via the exhaust valve 16. Owing to air being channeled into the engine cylinder from the inlet valve 14 as well as the exhaust valve 16 simultaneously, the volumetric efficiency of the internal combustion engine 10 is enhanced.

[00014] The working of the internal combustion engine 10 is described as an example. During the suction stroke of the internal combustion engine 10, the first lobe 28 of the cam 11 opens the exhaust valve 16. During this time, the inlet valve 14 is opened. Fresh air is channeled into the inlet valve 14, and simultaneously fresh air is channeled into the exhaust valve 16 via the air flow path 18. Due to the suction created by the movement of the piston within the engine cylinder, the mechanically actuated valve 24 is opened while the mechanically actuated valve 26 is closed. The fresh air that is channeled into the engine cylinder via the inlet valve 14 and via the exhaust valve 16 is used to combust fuel within the internal combustion engine 10. During the exhaust stroke, the exhaust gases are channeled from the engine cylinder to the outlet 22 of the engine block 12. Due to pressurized exhaust gases flowing to the outlet 22 of the engine block 12, the mechanically actuated valve 26 is opened, while the mechanically actuated valve 24 is closed. A portion of the exhaust gases that are channeled out of the engine cylinder via the mechanically actuated valve 26 is recirculated to the engine cylinder via an exhaust gas recirculation path 30. The remaining portion of the exhaust gas that is channeled out of the engine cylinder via the mechanically actuated valve 26 is vented out of the internal combustion engine 10.
[00015] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.