Description:FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]

TITLE OF INVENTION
Internal Combustion Engine

APPLICANT
TVS MOTOR COMPANY LIMITED, an Indian company, having its address at “Chaitanya”, No.12 Khader Nawaz Khan Road, Nungambakkam, Chennai 600 006, Tamil Nadu, India.

PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
[001] The present invention generally relates to an internal combustion engine. More particularly, the present invention relates to disposition and orientation of an exhaust sensor in the internal combustion engine.

BACKGROUND OF THE INVENTION
[002] Typically, a conventional motor vehicle comprises a lambda sensor (also called an oxygen sensor), located on an exhaust port of the motor vehicle, and between the exhaust manifold and a catalytic converter. Typically, the lambda sensor is located in an exhaust port in a cylinder head and behind the catalytic converter. The lambda sensor is adapted to determine an amount of unburnt oxygen in an exhaust gas discharged from an engine of the motor vehicle. An Electronic Control Unit (ECU) of the motor vehicle is configured to adjust an air-fuel mixture in an engine cylinder for optimum operation of the engine, based on the determination from the lambda sensors. Thus, the lambda sensors ensure that the exhaust gas discharged from the motor vehicle complies with standard emission regulations.
[003] Further, in existing engines, the lambda sensor is typically placed at an angle with respect to a flow direction of the exhaust gas. As such, the exhaust gases fail to impinge completely onto a probe or a sensing element of the lambda sensor, resulting in an inaccurate measurement of the remaining oxygen content in the exhaust emission. Also, in the conventional motor vehicles, the distance between the exhaust valves and the position of the lambda sensor is large, rendering a delay in the response time from the lambda sensor. Consequently, the engine control operation of the ECU is also delayed, resulting in inefficient operation of the engine and release of pollutants from the engine to surroundings through the exhaust gas, which is undesirable. Additionally, compactness of the engine is also affected since a separate opening in the exhaust port is required for mounting the lambda sensor. The opening may also render a crack in the exhaust port, due to which the measurement of the lambda sensor may also be inaccurate, which is undesirable.
[004] In view of the above, there is a need for an internal combustion engine, which addresses one or more limitations stated above.

SUMMARY OF THE INVENTION
[005] In one aspect, an internal combustion engine is disclosed. The internal combustion engine comprises a cylinder block that is provided with a combustion chamber. The combustion chamber is in fluid communication with an exhaust opening, wherein the exhaust opening is adapted to discharge exhaust gases generated in the combustion chamber. A cylinder head is connected to the cylinder block and is provided with an exhaust port in fluid communication with the exhaust opening, wherein the exhaust port being adapted to route the exhaust gases discharged from the combustion chamber to a muffler body. An exhaust sensor is disposed in the exhaust port and is placed on a cam chain window side of the cylinder head, wherein the exhaust sensor is oriented at an angle with respect to an axis of a cam chain window of the internal combustion engine.
[006] In an embodiment, the exhaust sensor is oriented horizontally to an axis C-C’ of the exhaust port.
[007] In an embodiment, the exhaust sensor is oriented parallelly to a plane D-D’ of the combustion chamber.
[008] In an embodiment, the exhaust sensor is positioned perpendicularly to a direction B of flow of the exhaust gases discharged from the exhaust port.
[009] In an embodiment, a top portion of the exhaust port is provided with a slot for receiving a probe of the exhaust sensor.
[010] In an embodiment, the exhaust sensor comprises a probe which is disposed in the exhaust port for determining quantity of unburnt oxygen in the exhaust gases.
[011] In an embodiment, the exhaust sensor is an oxygen sensor. The oxygen sensor is adapted to determine quantity of unburnt oxygen in the exhaust gases.
[012] In an embodiment, an exhaust valve is provided in the cylinder head and is operable between an open condition and a closed condition. The exhaust valve in the open condition is capable of allowing flow of the exhaust gas generated in the combustion chamber from the exhaust opening to the exhaust port.
BRIEF DESCRIPTION OF THE DRAWINGS
[013] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in 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 is a front view of a top portion of an internal combustion engine depicting position of an exhaust sensor, in accordance with an exemplary embodiment of the present invention.
Figure 2 is a rear view of the top portion of the internal combustion engine, in accordance with an exemplary embodiment of the present invention.
Figure 3 is a top view of the top portion of the internal combustion engine, in accordance with an exemplary embodiment of the present invention.
Figure 4 is a sectional view about a plane B-B’ of Figure 3, depicting location of a probe of the exhaust sensor in an exhaust port of the internal combustion engine, in accordance with an exemplary embodiment of the present invention.
Figure 5 is a sectional view about a plane C-C’ of Figure 4, depicting orientation of the probe of the exhaust sensor with respect to direction of flow of an exhaust gas from the exhaust port, in accordance with an exemplary embodiment of the present invention.
Figure 6 is a sectional view about the plane C-C’ of Figure 4, depicting flow of the exhaust gas over the probe of the exhaust sensor during an open condition of an exhaust valve, in accordance with an exemplary embodiment of the present invention.
Figure 7 is a rear view of the top portion of the internal combustion engine depicting inclination of the exhaust sensor with respect to an axis A-A’ of a cam chain window of the internal combustion engine, in accordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[014] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder.
[015] Figure 1 illustrates a top portion of an internal combustion engine 100 in accordance with an exemplary embodiment of the present disclosure. The internal combustion engine 100 (hereinafter referred to as “engine 100”) of the present invention may be typically used in any motor vehicle such as a two-wheeled vehicle, a three-wheeled vehicle, a four-wheeled vehicle or a multi-wheeled vehicle as per requirement. The engine 100 may also be used in any non-automotive applications such as a generator and the like as per feasibility and requirement. In the present invention, the top portion of the engine 100 is depicted and referred to as ‘engine 100’ for the sake of simplicity and understanding.
[016] Referring to Figures 2 and 3 in conjunction with Figure 1, the engine 100 comprises a cylinder block 102 provided with a combustion chamber 104 (for e.g. as shown in Figure 4). The combustion chamber 104 is adapted to generate a motive force during a combustion process. The motive force is transferred through a crankshaft (not shown) of the engine 100 to a machine, such as a transmission system of a motor vehicle, for operation. In the present embodiment, the engine 100 is disposed in the two-wheeled vehicle, and the motive force generated in the engine 100 is transmitted to wheels (not shown) of the two-wheeled vehicle for movement. The combustion chamber 104 is in fluid communication with an exhaust opening 106. The exhaust opening 106 (as shown in Figure 4) is adapted to discharge exhaust gases generated in the combustion chamber 104.
[017] Further, the engine 100 comprises a cylinder head 108 connected or mounted onto the cylinder block 102. The cylinder head 108 is provided with an exhaust port 110 (as shown in Figure 4) in fluid communication with the exhaust opening 106. The exhaust port 110 is adapted to route the exhaust gases discharged from the combustion chamber 104 to a muffler body (not shown) and subsequently to surroundings. In an embodiment, the exhaust opening 106 is defined in the cylinder head 108 and at a top portion of the combustion chamber 104.
[018] Referring to Figure 4 in conjunction with Figures 1-3, the engine 100 also comprises a camshaft assembly (not shown in Figures). The camshaft assembly is coupled to an exhaust valve 118. The exhaust valve 118 is operable between an open condition 118a (as shown in Figure 5) and a closed condition 118b (as shown in Figure 6) by the camshaft assembly. The exhaust valve 118 in the open condition 118a allows flow of the exhaust gas from the exhaust opening 106 to the exhaust port 110. In an embodiment, the exhaust valve 118 is provided in the cylinder head 108. Further, the camshaft assembly comprises a camshaft (not shown) provided with one or more cam members (not shown). The one or more cam members engage with the exhaust valve 118, for operating the exhaust valve 118 between the open condition 118a and the closed condition 118b. The camshaft of the camshaft assembly is in-turn coupled to the crankshaft of the engine 100 through a cam chain (not shown). Accordingly, the camshaft receives drive from the crankshaft through the cam chain, for rotation. A cam chain window 114 is provided on the cylinder head 108 for accommodating the cam chain that couples the camshaft and the crankshaft. The cam chain is positioned on a side of the engine 100 which is referred as a cam chain window side 108a (as shown in Figure 3). In the present embodiment, the cam chain window side 108a is a lateral side of the engine 100.
[019] Further, as shown in Figure 4, the camshaft assembly also comprises an intake valve 122 disposed in an intake port 120. The intake valve 122 is operable between an open position (not shown) and a closed position (not shown) by the camshaft. The intake valve 122 in the open position enables the intake port 120 to route air or an air-fuel mixture into the combustion chamber 104 for combustion.
[020] Referring to Figures 5-7 in conjunction with Figures 1-4, the engine 100 also comprises an exhaust sensor 112 disposed in the exhaust port 110 and placed on the cam chain window side 108a of the cylinder head 108. The exhaust sensor 112 is adapted to determine one or more parameters in the exhaust gas generated in the combustion chamber 104. The exhaust sensor 112 is typically in communication with a control unit (not shown). Accordingly, the control unit (not shown) based on the one or more parameters determined by the exhaust sensor 112 controls air or the air-fuel mixture entering the combustion chamber 104. In an embodiment, the exhaust sensor 112 is an oxygen sensor, wherein the oxygen sensor is adapted to determine quantity of unburnt oxygen in the exhaust gas. Based on the quantity of unburnt oxygen determined by the exhaust sensor 112, the control unit is adapted to control routing of air or air-fuel mixture entering the combustion chamber 104 for ensuring optimal performance from the engine 100.
[021] In the present embodiment, the exhaust sensor 112 comprises a probe 112a (as shown in Figures 5 and 6) disposed in the exhaust port 110 and a shank portion 112b (as shown in Figures 5 and 6) that extends from the probe 112a about a central axis E-E’ (for e.g. as shown in Figures 4 and 5). As such, inclination of the exhaust sensor 112 corresponds to the inclination of the axis E-E’. The probe 112a is placed within the exhaust port 110 such that, the exhaust gas routed from the combustion chamber 104 impinge onto the probe 112a for determining the one or more parameters in the exhaust gas. An aft end of the shank portion 112b is provided with a connector 112c (as shown in Figures 5 and 6) for establishing electrical connection with the control unit.
[022] In the present embodiment, a top portion 110a (as shown in Figure 4) of the exhaust port 110 is provided with a slot 116 (shown in Figure 4) for receiving the probe 112a (as shown in Figures 5 and 6) of the exhaust sensor 112, while the shank portion 112b is disposed outside of the engine 100. In an embodiment, the slot 116 is provided proximal to the exhaust opening 106. Such a construction ensures that the exhaust gas routed through the exhaust port 110 contacts the probe 112a with minimal delay, thereby enhancing responsiveness of the exhaust sensor 112.
[023] Furthermore, as depicted in Figure 7, the exhaust sensor 112 is oriented at an angle α with respect to an axis A-A’ of the cam chain window 114 of the internal combustion engine 100. In the present embodiment, the angle α between the axis A-A’ and the axis E-E’ of the exhaust sensor 112 is 90 degrees. Also, the exhaust sensor 112 is oriented horizontally to an axis C-C’ (as shown in Figure 4) of the exhaust port 110 and parallelly to a plane D-D’ (as shown in Figure 4) of the combustion chamber 104. In an embodiment, axis C-C’ is a central axis of the exhaust port 110. In the present embodiment, the axis E-E’ of the exhaust sensor 112 is overlapping onto the axis C-C’ of the exhaust port 110. In an embodiment, the plane D-D’ of the combustion chamber 104 is a plane perpendicular to a central axis (not shown) of the combustion chamber 104. Additionally, the exhaust sensor 112 is also positioned perpendicularly (depicted as angle ‘β’ in Figure 5) to a direction B (as shown in Figure 6) of flow of the exhaust gases discharged from the exhaust port 110. Particularly, the probe 112a of the exhaust sensor 112 is positioned perpendicularly to the direction B of the exhaust gases discharged from the combustion chamber 104 during the open condition 118a of the exhaust valve 118. In other words, the axis E-E’ of the exhaust sensor 112 is oriented perpendicularly to the direction of flow of exhaust gas from the exhaust port 110. Such an orientation of the exhaust sensor 112 ensures maximum impingement or contact of the exhaust gases with the probe 112a, thereby ensuring accurate determination of the one or more parameters in the exhaust gas, consequently ensuring better control over supply of air or air-fuel mixture into the combustion chamber 104.
[024] During operation of the engine 100, when the exhaust valve 118 is operated to the open condition 118a by the camshaft, the exhaust gas generated in the combustion chamber 104 is routed to the exhaust port 110. At this juncture, the exhaust gas impinges or contacts with the probe 112a. Upon impingement, the probe 112a determines the one or more parameters (or the amount of unburnt oxygen) in the exhaust gas. The control unit, based on the determination of the exhaust sensor 112, controls air or air-fuel mixture in the combustion chamber 104, thereby ensuring optimum operation of the engine 100.
[025] The claimed invention as disclosed above is not routine, conventional or well understood in the art, as the claimed aspects enable the following solutions to the existing problems in conventional technologies. Specifically, the claimed aspect of the engine 100 comprising the exhaust sensor 112 oriented perpendicularly to an axis A-A’ of the cam chain window 114, horizontally to an axis C-C’ of the exhaust port 110 and parallelly to a plane D-D’ of the combustion chamber 104 reduces delay in contact between the exhaust gas the exhaust sensor 112. As such, the delay in performance of the exhaust sensor 112 is reduced considerably. Further, the slot 116 in the top portion of the exhaust port 110 is also selected to reduce the delay in contact between the exhaust gas and the probe 112a. Further, the exhaust sensor 112 or the probe 112a is positioned perpendicularly or laterally to the flow direction B of the exhaust gas in the exhaust port 110. Such an orientation, ensures maximum impingement of the exhaust gases with the probe 112a, thereby ensuring accurate determination of the one or more parameters in the exhaust gas, consequently ensuring better control over supply of air or air-fuel mixture into the combustion chamber 104.

Reference numerals

100 Internal combustion engine
102 Cylinder block
104 Combustion chamber
106 Exhaust opening
108 Cylinder head
108a Cam chain window side
110 Exhaust port
110a Top portion of the exhaust port
112 Exhaust sensor
112a Probe
112b Shank portion
112c Connector
114 Cam chain window
116 Slot
118 Exhaust valve
118a Open condition of exhaust valve
118b Closed condition of exhaust valve
120 Intake port
122 Intake valve
A-A’ Axis of cam chain window
α Angle of orientation of the exhaust sensor with respect to axis A-A’
E-E’ Axis of exhaust sensor
C-C’ Axis of exhaust port
D-D’ Plane of combustion chamber
β Angle between axis E-E’ and axis A-A’ , Claims:WE CLAIM:
1. An internal combustion engine (100), comprising
a cylinder block (102), the cylinder block (102) being provided with a combustion chamber (104), the combustion chamber (104) being in fluid communication with an exhaust opening (106), wherein the exhaust opening (106) being adapted to discharge exhaust gases generated in the combustion chamber (104);
a cylinder head (108), the cylinder head (108) being connected to the cylinder block (102), the cylinder head (108) being provided with an exhaust port (110) in fluid communication with the exhaust opening (106), wherein the exhaust port (110) being adapted to route the exhaust gases discharged from the combustion chamber (104) to a muffler body; and
an exhaust sensor (112), the exhaust sensor (112) being disposed in the exhaust port (110) and placed on a cam chain window side (108a) of the cylinder head (108), wherein the exhaust sensor (112) is oriented at an angle (α) with respect to an axis (A-A’) of a cam chain window (114) of the internal combustion engine (100).

2. The internal combustion engine (100) as claimed in claim 1, wherein the exhaust sensor (112) is oriented horizontally to an axis C-C’ of the exhaust port (110).

3. The internal combustion engine (100) as claimed in claim 1, wherein the exhaust sensor (112) is oriented parallelly to a plane (D-D’) of the combustion chamber (104).

4. The internal combustion engine (100) as claimed in claim 1, wherein the exhaust sensor (112) is positioned perpendicularly to a direction (B) of flow of the exhaust gases discharged from the exhaust port (110).

5. The internal combustion engine (100) as claimed in claim 1, wherein a top portion (110a) of the exhaust port (110) is provided with a slot (116) for receiving a probe (112a) of the exhaust sensor (112).

6. The internal combustion engine (100) as claimed in claim 1, wherein the exhaust sensor (112) comprises a probe (112a), the probe (112a) being disposed in the exhaust port (110) for determining quantity of unburnt oxygen in the exhaust gases.

7. The internal combustion engine (100) as claimed in claim 1, wherein the exhaust sensor (112) is an oxygen sensor, the oxygen sensor being adapted to determine quantity of unburnt oxygen in the exhaust gases.

8. The internal combustion engine (100) as claimed in claim 1 comprises an exhaust valve (118) provided in the cylinder head (108) and operable between an open condition and a closed condition, the exhaust valve (118) in the open condition being capable of allowing flow of the exhaust gas generated in the combustion chamber (104) from the exhaust opening (106) to the exhaust port (110).

Dated this 1st day of November 2022

TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

(Nikhil Ranjan)
of Khaitan & Co
Reg No IN/PA-1471