Description:FIELD OF THE INVENTION
[001] Present invention relates to an Internal Combustion (IC) engine. More particularly, the present invention relates to a valve actuation mechanism for the IC engine.

BACKGROUND OF THE INVENTION
[002] It is a known fact that, Internal Combustion (IC) engines are provided with an intake valve and an exhaust valve. The intake valve is provided to an intake port and the exhaust valve is provided to an exhaust port of the IC engine. A valve actuation mechanism such as a camshaft is coupled to each of the intake valve and the exhaust valve, through a cam. The camshaft is adapted to control lift of the intake valve and the exhaust valve, thereby controlling opening of the intake port and the exhaust port. Thus, the camshaft is adapted to control intake of air or air-fuel mixture into a combustion chamber of the IC engine and discharge of exhaust gases from the combustion chamber. Accordingly, the valve actuation mechanism is adapted to control performance characteristics of the IC engine.
[003] Typically, the IC engine requires large amounts of air when operating at high speeds. However, the intake valve may close before enough air has entered the IC engine, thereby reducing performance. On the other hand, if the camshaft keeps the valves open for longer periods of time, performance issues occur in the IC engine at lower engine speeds.
[004] In order to overcome these limitations in conventional valve actuation mechanisms in the IC engine, the variable valve actuation mechanism is provided. The variable valve actuation mechanism is adapted to vary opening of the valves based on engine speed, thereby optimizing engine performance. Existing variable valve actuation mechanisms comprises a solenoid being controlled by a control unit. The control unit is adapted to operate the solenoid based on information received from a plurality of sensors.
[005] However, use of plurality of sensors requires additional circuitry and power inputs from the vehicle battery which in turn reduces the life of the vehicle battery. Furthermore, any delay in signals sent from the sensors can delay the actuation of the variable valve and therefore impede the performance of the vehicle, which is undesirable.
[006] In view of the above, there is a need for a valve actuation mechanism for an IC engine that addresses at least some of the limitations mentioned above.

SUMMARY OF THE INVENTION
[007] In an embodiment, a valve actuation mechanism for an Internal Combustion (IC) engine is provided. The valve actuation mechanism comprises a camshaft coupled to a crankshaft of the IC engine. A first cam lobe is disposed concentrically on the camshaft. The first cam lobe is adapted to actuate one or more valves of the IC engine through a follower. A second cam lobe is disposed concentrically on the camshaft the second cam lobe is provided with a cam profile adapted to alter an opening time and a closing time of the one or more valves than the first cam lobe, wherein the second cam lobe being adapted to selectively actuate the one or more valves. Further, an engaging unit is disposed in the camshaft and coupled to the follower of the one or more valves. The engaging unit is adapted to selectively engage the follower to the second cam lobe. A stopper pin having a first end coupled to an actuator and a second end rested on the camshaft is also provided. The stopper pin is operable between a first position and a second position based on an engine speed of the IC engine for actuating variable valve actuation based on the engine speed.
[008] In an embodiment, the stopper pin in the second position locks in position by a locking member provided on the camshaft and allows actuation of the engaging unit to an activated position. The engaging unit at the activated position engages the follower to the second cam lobe.
[009] In an embodiment, the stopper pin in the first position is adapted to enable the engaging unit to maintain engagement between the first cam lobe actuates the one or more valves.
[010] In an embodiment, the first end of the stopper pin is connected to the actuator through a damping member.
[011] In an embodiment, the stopper pin is in the first position when an engine speed of the IC engine is below a preset speed, and the stopper pin is operated to the second position when the engine speed of the IC engine exceeds the preset speed.
[012] In an embodiment, the engaging unit is a torsion spring. The torsion spring is concentrically mounted to the camshaft and coupled to the follower of the one or more valves.
[013] In an embodiment, the first position is a disengaged position of the stopper pin with the camshaft, and the second position is an engaged position of the stopper pin with the camshaft. The actuator actuates the stopper pin vertically between the first position and the second position.
[014] In an embodiment, the locking member is provided on a cylindrical tab positioned adjacently to the second cam lobe. The cylindrical tab is provided with a circumferential groove adapted to guide the stopper pin during movement between the first position and the second position.
[015] In another aspect, the IC engine is provided. The IC engine comprises a crankcase, a cylinder head mounted on the crankcase and the valve actuation mechanism disposed in the cylinder head. The valve actuation mechanism comprises the camshaft coupled to the crankshaft of the IC engine. The first cam lobe is disposed concentrically on the camshaft. The first cam lobe is adapted to actuate one or more valves of the IC engine through a follower. The second cam lobe is disposed concentrically on the camshaft the second cam lobe is provided with the cam profile adapted to alter the opening time and the closing time of the one or more valves than the first cam lobe, wherein the second cam lobe is adapted to selectively actuate the one or more valves. Further, the engaging unit is disposed in the camshaft and coupled to the follower of the one or more valves. The engaging unit is adapted to selectively engage the follower to the second cam lobe. The stopper pin has the first end coupled to the actuator and the second end rested on the camshaft is also provided. stopper pin is operable between a first position and a second position based on an engine speed of the IC engine for actuating variable valve actuation based on the engine speed.

BRIEF DESCRIPTION OF ACCOMAPNYING DRAWINGS
[016] 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 an exploded view of a cylinder head of an Internal Combustion (IC) engine, in accordance with an exemplary embodiment of the present invention.
Figure 2 is a perspective view of the cylinder head, in accordance with an exemplary embodiment of the present invention.
Figure 3 is a top view of the cylinder head, in accordance with an exemplary embodiment of the present invention.
Figure 4 is a schematic view of a valve actuation mechanism for the IC engine depicting a stopper being in a first position, in accordance with an exemplary embodiment of the present invention.
Figure 5 is a schematic view of the valve actuation mechanism depicting the stopper in a second position, in accordance with an exemplary embodiment of the present invention.
Figure 6 is a schematic view of the valve actuation mechanism depicting the stopper in the second position, in accordance with an exemplary embodiment of the present invention.
Figure 7 is a top view of the valve actuation mechanism, in accordance with an exemplary embodiment of the present invention.
Figure 8 is a sectional view of the valve actuation mechanism about an axis A-A’ of Figure 7, in accordance with an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[017] Present invention discloses a valve actuation mechanism for an Internal Combustion (IC) engine. The valve actuation mechanism comprises an engaging unit disposed on the camshaft and coupled to a follower of one or more valves of the IC engine. A stopper pin coupled to an actuator is operated to a second position on the camshaft, when speed of the IC engine exceeds a preset speed. Actuation of the stopper pin to the second position allows actuation of the engaging unit to an activated position, thereby enabling engagement of the follower to the second cam lobe.
[018] The valve actuation mechanism of the present invention is capable of enabling variable valve actuation in the IC engine without the need for a plurality of sensors. Consequently, the power consumption by the plurality of sensors of a battery pack are minimised in the IC engine. Thus, enhancing battery life of the battery pack in the vehicle. Also, by mitigating the need for the plurality of sensors, the valve actuation mechanism is simple in construction and devoid requirement of complex circuitry for enabling variable valve actuation in the IC engine.
[019] Figure 1 is an exploded view of a cylinder head 118 of an Internal Combustion (IC) engine, in accordance with an exemplary embodiment of the present invention. The IC engine is mountable onto a vehicle such as a two-wheeled vehicle, a three-wheeled vehicle or any multi-wheeled vehicle. The IC engine is adapted to provide the motive force required for operation and/or movement of the vehicle. In an embodiment, the IC engine is an overhead valve type engine.
[020] The cylinder head 118 is mounted onto a crankcase (not shown) of the IC engine with a cylinder block (not shown). In other words, the cylinder block is mounted between the cylinder head 118 and the crankcase. The cylinder head 118 may comprises a plurality of slots (not shown) that align with openings provided on the cylinder block and holes (not shown) provided on the crankcase. Each of the plurality of slots, openings and the holes are adapted to receive a fastener, thereby fastening the cylinder head 118 and the cylinder block to the crankcase.
[021] The cylinder head 118 comprises a top portion 118a adapted to accommodate and support one or more valves (not shown). Each of the one or more valves may be a poppet valve known in the art. The one or more valves comprises at least one intake valve (not shown) and at least one exhaust valve (not shown). Each of the at least one intake valve is disposed in a valve seat of an intake port (not shown), while each of the at least one exhaust valve is disposed in a valve seat of an exhaust port (not shown). The intake port and the exhaust port are communicably coupled to a combustion chamber of the IC engine. The intake port routes air or air-fuel mixture into the combustion chamber provided in the cylinder block, while the exhaust port discharges exhaust gases from the combustion chamber.
[022] Referring to Figure 2 in conjunction with Figure 1, the top portion 118a of the cylinder head 118 accommodates a valve actuation mechanism 100 (shown in Figures 4-8). In the present embodiment, the valve actuation mechanism 100 is accommodated on a front side of the top portion 118a in a top view (as shown in Figure 3) of the cylinder head 118. The valve actuation mechanism 100 is coupled to each of the one or more valves. In an embodiment, the valve actuation mechanism 100 is coupled to each of the one or more valves through a rocker arm assembly (not shown). The valve actuation mechanism 100 is adapted to control opening and closing time of the intake port and the exhaust port (with respect to the intake port and the exhaust port) by operating the intake valve and the exhaust valve, thereby controlling performance parameters of the IC engine. In an embodiment, the valve actuation mechanism 100 is adapted to control lift-off of the intake valve and the exhaust valve from their respective valve seat for controlling opening and closing time of the intake port and the exhaust port respectively. A head cover 122 (as shown in Figure 1) is also mounted on the top portion 118a of the cylinder head 118. The head cover 122 may be mounted on the top portion 118a of the cylinder head 118, through conventional mounting techniques known in the art such as fastening, for enclosing the valve actuation mechanism 100 and the one or more valves.
[023] In an embodiment, one valve actuation mechanism 100 is provided in the cylinder head 100 for operating one set of the intake valves and the exhaust valves. As such, if multiple sets of intake valves and the exhaust valves are provided in the IC engine, multiple valve actuation mechanisms 100 are provided in the cylinder head 118.
[024] Referring to Figure 3 in conjunction with Figures 1 and 2, the cylinder head 118 is further provided with a cam-chain window 124. The cam-chain window 124 enables extension of a power transmission member from a crankshaft (not shown) disposed in the crankcase upto the valve actuation mechanism 100. Thus, the cam-chain window 124 enables connection between the crankshaft and the valve actuation mechanism 100. In an embodiment, the power transmission member connecting the crankshaft and the valve actuation mechanism 100 is a chain member (not shown). The chain member engages with the crankshaft and a sprocket member 126 of the valve actuation mechanism 100.
[025] Figure 4 is a schematic view of the valve actuation mechanism 100 for the IC engine, in accordance with an exemplary embodiment of the present invention. The valve actuation mechanism 100 comprises a camshaft 102 that is coupled to the crankshaft of the IC engine. The camshaft 102 is an elongated member that extends longitudinally from a first end 102a up to a second end 102b. The extension of the camshaft 102 is considered based on size of the cylinder head 118 and the number of valves to be engaged. The camshaft 102 is disposed on the cylinder head 118 such that, the second end 102b is facing the cam-chain window 124. In an embodiment, the camshaft 102 is disposed on the cylinder head 118 through bearing members 128 for minimizing friction at contact locations between the camshaft 102 and the cylinder head 118. The bearing members 128 are provided at the first end 102a and the second end 102b. Further, the camshaft 102 is provided with the sprocket member 126 for engagement with the crankshaft through the chain member. As the second end 102b of the camshaft 102 faces the cam-chain window 124, the sprocket member 126 is located at the second end 102b. In an embodiment, the second end 102b of the camshaft 102 is provided with a keyway (not shown) for receiving and locking the sprocket member 126 onto the camshaft 102.
[026] In addition, the camshaft 102 comprises a shaft portion 130 (as shown in Figure 8) and a lobe portion 132 (as shown in Figure 8). The shaft portion 130 is provided with a plurality of splines and the lobe portion 132 is provided with a plurality of grooves. Accordingly, the lobe portion 132 is slidably mounted onto the shaft portion 130.
[027] Further, the camshaft 102 is provided with a first cam lobe 104 disposed concentrically on the camshaft 102. Particularly, the lobe portion 132 of the camshaft 102 is provided with the first cam lobe 104. The first cam lobe 104 may be provided at a central portion of the camshaft 102. The first cam lobe 104 is defined or provided with a cam profile that engages with one or more valves. The first cam lobe is adapted to engage with the one or more valves through a follower 120 (as shown in Figure 1). The follower 120 engages with the one or more valves through the rocker arm assembly. In the present embodiment, only a shaft portion of the follower 120 is depicted in the drawings for the sake of brevity. The first cam lobe 104 is adapted to actuate the one or more valves.
[028] In an embodiment, the term “first cam lobe” refers to a cam lobe having a cam profile that is capable of actuating the intake valve and the exhaust valve. The first cam lobe 104 is adapted to lift the intake valve and the exhaust valve from their respective valve seats on the intake port and the exhaust port, for controlling operation of the IC engine. Lifting or actuation of the intake valve and the exhaust valve controls opening and closing time of the intake valve and the exhaust valve. In an embodiment, the first cam lobe 104 may refer to a set of cam lobes that are capable of selectively operating the intake valve and the exhaust valve. In an embodiment, the multiple first cam lobes can be provided, if multiple intake valves and exhaust valves are provided in the IC engine.
[029] Further, the camshaft 102 is provided with a second cam lobe 106 disposed concentrically on the camshaft 102. Particularly, the lobe portion 132 of the camshaft 102 is provided with the second cam lobe 106. The second cam lobe 106 may be provided proximally or adjacently to the first end 102a of the camshaft 102. The second cam lobe 106 may be placed at a distance from the first cam lobe 104. The second cam lobe 106 is provided with a cam profile adapted to alter the opening and closing time of the one or more valves than the first cam lobe 104. In other words, the second cam lobe 106 is provided with a cam profile that is different than the cam profile of the first cam lobe 104. In an embodiment, the cam profile of the second cam lobe 106 is provided in order to cater to performance requirements during high engine speeds of the IC engine. In an exemplary embodiment, the second cam lobe 106 being diametrically greater than the first cam lobe 104.
[030] In an embodiment, the term “second cam lobe” refers to a cam lobe having a cam profile that is capable of actuating the intake valve and the exhaust valve upon engagement. The second cam lobe 106 is adapted to lift the intake valve and the exhaust valve from their respective valve seats on the intake port and the exhaust port, for controlling operation of the IC engine. In an embodiment, the second cam lobe 106 may refer to a set of cam lobes that are capable of selectively operating the intake valve and the exhaust valve. In an embodiment, the multiple second cam lobes can be provided, if multiple intake valves and exhaust valves are provided in the IC engine.
[031] Further, an engaging unit 108 is disposed on the camshaft 102 and coupled to the follower 120 of the one or more valves. In the present embodiment, the engaging unit 108 is disposed concentrically on the camshaft 102. The engaging unit 108 is adapted to selectively engage the follower 120 to the second cam lobe 106 from the first cam lobe 104, thereby altering the opening and closing time of the one or more valves. Engagement of follower 120 with the second cam lobe 106 refers to engagement of the one or more valves with the second cam lobe 106. The engaging unit 108 is adapted to selectively engage the follower 120 to the second cam lobe 106 based on engine speed of the IC engine.
[032] In an embodiment, the engaging unit 108 is a torsion spring. The engaging unit 108 comprises a first end 108a and a second end 108b (as shown in Figure 8). The first end 108a is fixed or rested on the shaft portion 130 of the camshaft 102 and the second end 108b engages with the follower 120 (not shown in Figure 8). As such, extension or contraction of the first end 108a relative to the second end 108b, enables relative movement of the follower 120 on the shaft portion 130. Also, the relative movement of the follower 120 enables selective engagement between the first cam lobe and the second cam lobe. Thus, enable a variable valve actuation through the valve actuation mechanism 100. In an embodiment, the shaft portion 130 is provided with a sleeve 134, wherein the sleeve 134 is adapted to act as an anchor for the second end 108b of the engaging unit 108. In an embodiment, the first end 108a is rested on the shaft portion 130 of the camshaft 102 and the second end 108b is rested with the follower 120 through conventional techniques known in the art such as welding, brazing and the like.
[033] In an embodiment, the follower 120 may be provided with outer splines (not shown) that are adapted to engage with the first cam lobe 104 or the second cam lobe 106. As such, movement of the engaging unit 108, selectively engages the follower 120 with the first cam lobe 104 or the second cam lobe 106.
[034] Further, the valve actuation mechanism 100 comprises a stopper pin 110 having a first end 110a coupled to an actuator 112 and a second end 110b rested on the camshaft 102. The stopper pin 110 is a cylindrical pin member that is engaged to the actuator 112 through a damping member 116. The damping member 116 has one end fixed to the actuator 112 and an other end fixed to the stopper pin 110. The damping member 116 is adapted to facilitate movement between the first position FP and the second position SP upon actuation of the actuator 112. In an embodiment, the damping member 116 is a spring member. In an embodiment, the actuator 112 is a solenoid actuator that is positioned directly above the camshaft 102. The actuator 112 is also positioned to be inline with a central axis (not shown) of the camshaft 102 (as shown in Figure 7).
[035] The stopper pin 110 is operable between a first position FP (as shown in Figure 4) and a second position SP (as shown in Figures 5 and 7) based on the engine speed of the IC engine. The stopper pin 110 is maintained in the first position FP by the actuator 112 when the engine speed is below a preset speed. The stopper pin 110 is operated to the second position SP by the actuator 112 when the engine speed is above the preset speed.
[036] In an embodiment, the first position FP is a disengaged position of the stopper pin 110 with the camshaft 102. In another embodiment, the second position SP is an engaged position of the stopper pin 110 with the camshaft 102. In an embodiment, the actuator 112 actuates the stopper pin 110 vertically (in a top-down direction when viewed in Figure 4) between the first position FP and the second position SP.
[037] The stopper pin 110 in the first position FP is adapted to enable the engaging unit 108 to maintain engagement between the first cam lobe 104 and the follower 120 of the one or more valves. Thus, at the first position FP of the stopper pin 110, the valve actuation mechanism 100 operates the IC engine with the first cam lobes.
[038] Further, the stopper pin 110 in the second position SP locks in position by a locking member 114 provided on the camshaft 102 and allows actuation of the engaging unit 108 to an activated position. The term “activated position” of the engaging unit 108 may be a stressed position such as an extended position or a retracted position on the camshaft 102. The engaging unit 108 at the activated position engages the follower 120 to the second cam lobe 106, thereby varying opening and closing times of the one or more valve than that of the first cam lobe. In other words, at the second position SP of the stopper pin 110, the valve actuation mechanism 100 operates the IC engine with the second cam lobes.
[039] In an embodiment, the locking member 114 provided on the camshaft 102 may be a slot (i.e. a projection) or a protrusion. In another embodiment, the locking member 114 is provided on a cylindrical tab 136 (as shown in Figure 6) that may be positioned adjacently to the second cam lobe 106 and towards the first end 102a of the camshaft 102. The cylindrical tab 136 may include a circumferential groove 136a that is adapted to act as a guide to the stopper pin 110 during movement from or between the first position FP and the second position SP.
[040] In an embodiment, the actuator 112 is communicably coupled to a control unit (not shown) such as a vehicle control unit (not shown). The vehicle control unit is adapted to monitor the engine speed of the IC engine, and accordingly operate the actuator 112 to actuate the stopper pin 110 to the second position SP from the first position FP when the engine speed exceeds the preset speed. The vehicle control unit is also adapted to operate the actuator 112 for operating the stopper pin 110 to the first position FP from the second position SP, when the engine speed is below the preset speed. In an embodiment, the preset speed is 2000 to 3000 Rotations Per Minute (RPM) of the IC engine. In an embodiment, the vehicle control unit is communicably coupled to an engine speed sensor of the IC engine for monitoring the engine speed.
[041] In an operational embodiment, upon turning ON the vehicle control unit monitors the engine speed of the IC engine. At this scenario, the stopper pin 110 is in the first position FP, and thus the first cam lobe is in engagement with the one or more valves through the follower 120. When a throttle valve of the IC engine is opened, which may be by pressing a throttle member provided on the vehicle, flow of air or air/fuel mixture is increased to the IC engine. Consequently, the power generated in the IC engine is increased, thereby increasing the engine speed (i.e. speed of rotation of the crankshaft). When the vehicle control unit monitors that the engine speed exceeds the preset speed, the vehicle control unit operates the actuator 112 such that the stopper pin 110 moves from the first position FP to the second position SP. At this juncture, the second end 110b of the stopper pin 110 moves downwardly, preferably along the groove 136b on the cylindrical tab 136, thereby moving from the first position FP to the second position SP. At the second position SP, the second end 110b of the stopper pin 110 engages with the locking member 114 thereby locking the lobe portion 132. Locking of the lobe portion 132 enables the engaging unit 108 to be operated to the actuated position, thereby moving the follower 120 from location of the first cam lobe 104 to the location of the second cam lobe 106 (arrow indication provided in Figure 6). At this juncture, the follower 120 engages and locks onto the second cam lobe 106. Thus, the second cam lobe operates the follower 120 and hence the one or more valves of the IC engine, when the engine speed is above the preset speed.
[042] When the engine speed of the IC engine reduces below the preset speed, due to release of the throttle member, the vehicle control unit operates the stopper pin 110 from the second position SP to the first position FP. The stopper pin 110 traverses along the circumferential groove 136a while traversing from the second position SP to the first position FP. At this juncture, the follower 120 reverts back to position of the first cam lobe 104 (arrow indication provided in Figure 5) due to retraction of the engaging unit 114. The follower 120 thus disengages from the second cam lobe 106 and engages onto the first cam lobe 104. Thus, the first cam lobe 104 operates the follower 120 and hence the one or more valves of the IC engine, when the engine speed is below the preset speed.
[043] 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 providing the stopper pin that enables movement of the follower through the engaging unit for selective engagement with the first cam lobe and the second cam lobe based the engine speed provides a simple variable valve actuation mechanism. Thus, the need for the plurality of sensors for controlling the valve actuation mechanism is mitigated in the present invention. Consequently, the power consumption by the plurality of sensors of a battery pack are minimised in the IC engine. Thus, enhancing battery life of the battery pack in the vehicle. Also, by mitigating the need for the plurality of sensors, the valve actuation mechanism devoids requirement of complex circuitry for enabling variable valve actuation in the IC engine. Moreover, mitigating the plurality of sensors makes the valve actuation mechanism inexpensive, consequently reducing cost involved in the IC engine. Further, the claimed invention provides modularity of using the variable valve transmission mechanism in any IC engine irrespective of the capacity of the IC engine.
[044] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

Reference Numerals and Characters
100 – Valve actuation mechanism
102 – Camshaft
104 – First cam lobe
106 – Second cam lobe
108 – Engaging unit
110 – Stopper pin
110a – First end of stopper pin
110b – Second end of stopper pin
112 – Actuator
114 – Locking member
116 – Damping member
118 – Cylinder head
120 – Follower
122 – Head cover
124 – Cam-chain window
126 – Sprocket member
128 – Bearing members
130 – Shaft portion
132 – Lobe portion
134 – Sleeve
136 – Cylindrical tab
136a – Circumferential groove

, Claims:WE CLAIM:
1. A valve actuation mechanism (100) for an Internal Combustion (IC) engine, the valve actuation mechanism (100) comprising:
a camshaft (102) coupled to a crankshaft of the IC engine;
a first cam lobe (104) disposed concentrically on the camshaft (102), the first cam lobe (104) being adapted to actuate one or more valves of the IC engine through a follower (120);
a second cam lobe (106) disposed concentrically on the camshaft (102), the second cam lobe (106) being provided with a cam profile adapted to alter an opening time and a closing time of the one or more valves than the first cam lobe (104), wherein the second cam lobe (106) being adapted to selectively actuate the one or more valves;
an engaging unit (108) disposed in the camshaft (102) and being coupled to the follower (120) of the one or more valves, the engaging unit (108) being adapted to selectively engage the follower (120) to the second cam lobe (106); and
a stopper pin (110) having a first end (110a) coupled to an actuator (112) and a second end (110b) rested on the camshaft (102), the stopper pin (110) operable between a first position (FP) and a second position (SP) based on an engine speed of the IC engine for actuating variable valve actuation based on the engine speed.

2. The valve actuation mechanism (100) as claimed in claim 1, wherein the stopper pin (110) in the second position (SP) locks in position by a locking member (114) provided on the camshaft (102) and allows actuation of the engaging unit (108) to an activated position, the engaging unit (108) at the activated position engages the follower (120) to the second cam lobe (106).

3. The valve actuation mechanism (100) as claimed in claim 1, wherein the stopper pin (110) in the first position (FP) is adapted to enable the engaging unit (108) to maintain engagement between the first cam lobe (104) actuates the one or more valves.

4. The valve actuation mechanism (100) as claimed in claim 1, wherein the first end (110a) of the stopper pin (110) being connected to the actuator (112) through a damping member (116).

5. The valve actuation mechanism (100) as claimed in claim 1, wherein the stopper pin (110) is in the first position (FP) when an engine speed of the IC engine is below a preset speed, and the stopper pin (110) is operated to the second position (SP) when the engine speed of the IC engine exceeds the preset speed.

6. The valve actuation mechanism (100) as claimed in claim 1, wherein the engaging unit (108) being a torsion spring, the torsion spring being concentrically mounted to the camshaft (102) and coupled to the follower of the one or more valves.

7. The valve actuation mechanism (100) as claimed in claim 1, wherein the first position (FP) being a disengaged position of the stopper pin (110) with the camshaft 102, and the second position (SP) being an engaged position of the stopper pin 110 with the camshaft 102,
wherein the actuator (112) actuates the stopper pin (110) vertically between the first position (FP) and the second position (SP).

8. The valve actuation mechanism (100) as claimed in claim 1, wherein the locking member (114) being provided on a cylindrical tab (136) positioned adjacently to the second cam lobe (106), the cylindrical tab (136) being provided with a circumferential groove (136a) adapted to guide the stopper pin (110) during movement between the first position (FP) and the second position (SP).

9. An Internal Combustion (IC) engine, comprising:
a crankcase;
a cylinder head (118) mounted on the crankcase;
a valve actuation mechanism (100) disposed in the cylinder head (118), the valve actuation mechanism (100) comprising:
a camshaft (102) coupled to a crankshaft of the IC engine;
a first cam lobe (104) disposed concentrically on the camshaft (102), the first cam lobe (104) being adapted to actuate one or more valves of the IC engine through a follower (120);
a second cam lobe (106) disposed concentrically on the camshaft (102), the second cam lobe (106) being provided with a cam profile adapted to alter an opening time and a closing time of the one or more valves than the first cam lobe (104), wherein the second cam lobe (106) being adapted to selectively actuate the one or more valves;
an engaging unit (108) disposed in the camshaft (102) and being coupled to the follower (120) of the one or more valves, the engaging unit (108) being adapted to selectively engage the follower (120) to the second cam lobe (106); and
a stopper pin (110) having a first end (110a) coupled to an actuator (112) and a second end (110b) rested on the camshaft (102), the stopper pin (110) operable between a first position (FP) and a second position (SP) based on an engine speed of the IC engine for actuating variable valve actuation based on the engine speed.

10. The IC engine as claimed in claim 9, wherein the stopper pin (110) in the second position (SP) locks in position by a locking member (114) provided on the camshaft (102) and allows actuation of the engaging unit (108) to an activated position, the engaging unit (108) at the activated position engages the follower (120) to the second cam lobe (106).

11. The IC engine as claimed in claim 9, wherein the stopper pin (110) in the first position (FP) is adapted to enable the engaging unit (108) to maintain engagement between the first cam lobe (104) actuates the one or more valves.

12. The IC engine as claimed in claim 9, wherein the first end (110a) of the stopper pin (110) being connected to the actuator (112) through a damping member (116).

13. The IC engine as claimed in claim 9, wherein the stopper pin (110) is in the first position (FP) when an engine speed of the IC engine is below a preset speed, and the stopper pin (110) is operated to the second position (SP) when the engine speed of the IC engine exceeds the preset speed.

14. The IC engine as claimed in claim 9, wherein the engaging unit (108) being a torsion spring, the torsion spring being concentrically mounted to the camshaft (102) and coupled to the follower (120) of the one or more valves.

Dated this 29th day of January 2024

TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

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