Claims:WE CLAIM:
1. A flywheel (100) for an ignition system of a hybrid vehicle (200), the flywheel (100) comprising:
a shaft member (102) coupled to a crankshaft (204) disposed in a crankcase (206) of an internal combustion engine (202), and
a plurality of wing members (104) extending radially from the shaft member (102), wherein at least one of the plurality of wing members (104) is defined with one or more pip members (106), the one or more pip members (106) interact with a pulsar coil (208) of the ignition system for enabling a control unit in the vehicle (200) to determine an engine speed and/or a position of the crankshaft (204) in the internal combustion engine (202).

2. The flywheel (100) as claimed in claim 1, wherein each of the plurality of wing members (104) is defined with a mounting provision (108) for receiving a centrifugal fan.

3. The flywheel (100) as claimed in claim 1, wherein each of the plurality of wing members (104) is a triangular shaped wing member.

4. The flywheel (100) as claimed in claim 1, wherein the at least one wing member (104) having the one or more pip members (106) comprises a slot (110) for mass balancing and reducing torsional vibrations in the flywheel (100).

5. The flywheel (100) as claimed in claim 1, wherein the shaft member (102) comprises a hollow boss (112a) having an internal key slot (112b) for engagement with the crankshaft (204).

6. The flywheel (100) as claimed in claim 1 is mounted on a right-hand side (206a) of the crankcase (206) for providing idling stability.

7. The flywheel (100) as claimed in claim 1 is manufactured via a sheet metal material.

8. The flywheel (100) as claimed in claim 1, wherein each of the one or more pip members (106) is an L-shaped protrusion.

9. An internal combustion engine (202) for a hybrid vehicle (200), the internal combustion engine (202) comprising:
an ignition system comprising:
at least one battery (234) disposed in the vehicle (200) and coupled to a starter motor (232) mounted on a crankcase (206) of an internal combustion engine (202), the at least one battery (234) adapted to operate the starter motor (232) for starting the internal combustion engine (202), and
a flywheel (100) mounted onto the crankcase (206) and positioned proximal to a pulsar coil (208), the flywheel (100) comprising:
a shaft member (102) coupled to a crankshaft (204) disposed in the crankcase (206), and
a plurality of wing members (104) extending radially from the shaft member (102), wherein at least one of the plurality of wing members (104) is defined with one or more pip members (106), the one or more pip members (106) interact with the pulsar coil (208) for enabling a control unit to determine an engine speed and/or a position of the crankshaft (204).

10. The internal combustion engine (202) as claimed in claim 9, wherein each of the plurality of wing members (104) is defined with a mounting provision (108) for receiving a centrifugal fan.

11. The internal combustion engine (202) as claimed in claim 9, wherein each of the plurality of wing members (104) is a triangular shaped wing member.

12. The internal combustion engine (202) as claimed in claim 9, wherein the at least one wing member (104) having the one or more pip members (106) comprises a slot (110) for mass balancing and reducing torsional vibrations in the flywheel (100).

13. The internal combustion engine (202) as claimed in claim 9, wherein the shaft member (102) comprises a hollow boss (112a) having an internal key slot (112b) for engagement with the crankshaft (204).

14. The internal combustion engine (202) as claimed in claim 9, wherein the at least one battery (234) is coupled to a battery module (238) of the vehicle (200), the battery module (238) adapted to charge the at least one battery (234).

15. The internal combustion engine (202) as claimed in claim 9, wherein the at least one battery (234) is coupled to electrical components of the vehicle (200), the at least one battery (234) adapted to selectively power the electrical components.

16. A hybrid vehicle (200), the vehicle (200) comprising:
an internal combustion engine (202) mounted onto a frame member (218);
at least one battery (234) coupled to a starter motor (232) mounted on a crankcase (206) of the internal combustion engine (202), the at least one battery (234) adapted to operate the starter motor (232) for starting the internal combustion engine (202),
a flywheel (100) mounted onto the crankcase (206) and positioned proximal to a pulsar coil (208), the flywheel (100) comprising:
a shaft member (102) coupled to a crankshaft (204) disposed in the crankcase (206), and
a plurality of wing members (104) extending radially from the shaft member (102), wherein at least one of the plurality of wing members (104) is defined with one or more pip members (106), the one or more pip members (106) interact with the pulsar coil (208) for enabling a control unit to determine an engine speed and/or a position of the crankshaft (204).

17. The hybrid vehicle (200) as claimed in claim 16, wherein each of the plurality of wing members (104) is defined with a mounting provision (108) for receiving a centrifugal fan.

18. The hybrid vehicle (200) as claimed in claim 16, wherein each of the plurality of wing members (104) is a triangular shaped wing member.

19. The hybrid vehicle (200) as claimed in claim 16, wherein the at least one wing member (104) having the one or more pip members (106) comprises a slot (110) for mass balancing and reducing torsional vibrations in the flywheel (100).

20. The hybrid vehicle (200) as claimed in claim 16, wherein the shaft member (102) comprises a hollow boss (112a) having an internal key slot (112b) for engagement with the crankshaft (204).

21. The hybrid vehicle (200) as claimed in claim 16, wherein the at least one battery (234) is coupled to a battery module (238) of the vehicle (200), the battery module (238) adapted to charge the at least one battery (234).

22. The hybrid vehicle (200) as claimed in claim 16, wherein the at least one battery (234) is coupled to electrical components of the vehicle (200), the at least one battery (234) adapted to selectively power the electrical components.

Dated this 9th day of December 2021

TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

(Nikhil Ranjan)
of Khaitan & Co
Reg No IN/PA-1471 , Description:FIELD OF THE INVENTION
[001] The present invention relates to an internal combustion engine of a hybrid vehicle, more particularly relates to a flywheel and an ignition system for the internal combustion engine.

BACKGROUND OF THE INVENTION
[002] Typically, in a hybrid vehicle, an internal combustion engine is provided, which is adapted to convert heat energy into mechanical energy for movement of vehicle. A part of the mechanical energy generated is the engine is converted to electrical energy for powering electrical systems of the vehicle. In addition, the mechanical energy generated by the engine is also employed for operating a starting system for cranking the engine and for ignition system to ignite the fuel-air mixture.
[003] Typically, the ignition system comprises of an Electric Control Unit (ECU), a Transistor controlled ignition (TCI) unit powered by a battery, an ignition coil, spark plug, a throttle position sensor, a Magneto assembly having a rotor and a stator with a pulsar coil. The rotor consists of permanent magnets which generates rotating magnetic field required to generate electricity. Outside the rim of the rotor, one or more pips are provided that sensed by the pulsar coil. The stator consists of a series of coils which are used to generate electricity from the rotating magnetic field. The TCI senses an engine speed and a throttle position using pulsar coil, one or more pips in the magneto rotor and throttle position sensor respectively. Based on the engine speed and the throttle position, the TCI/ECU decides the ignition timing. The TCI/ECU also senses the crank shaft position using the pulsar coil and the one or more pips in the magneto rotor to trigger the ignition. The pulse is sent to the ignition coil which steps up the voltage and the high voltage pulse is provided to the spark plug as a spark. The magneto rotor also acts as an alternator which generates electrical energy using the mechanical energy in the crank shaft to charge the battery. In addition to the above stated roles, the magneto rotor also acts as a flywheel which stores mechanical energy and reduces the fluctuation in Engine speed due to the fluctuation in engine torque. Also, a centrifugal fan is mounted on the rotor which can force cool the engine the engine.
[004] Further, in conventional ignition systems, rotation of magneto assembly including the stator, generates torque required for movement of the vehicle. As such, higher the rotation inertia of the magneto assembly, higher the torque provided for movement of the vehicle. However, a portion of torque generated by the magneto assembly is used for charging the battery. As such, the net braking torque available for driving the vehicle reduces, consequently reducing acceleration of the vehicle. Also, due to high rotary inertia of magneto rotor, the time taken for engine to accelerate to the clutch in speed from idling speed and vice versa increases, thereby the time taken to engage the clutch increases. Additionally, due to interaction between permanent magnets of the rotor and the stator, ‘clogging torque’ or variation in torque production persists which is particularly prominent in lower speeds. The variation in torque production generates jerkiness as well as a speed ripple within the engine, reducing fatigue life of the crankshaft. Consequently, the performance as well as fuel economy of the vehicle reduces, which is undesirable.
[005] In view of the above, there is a need for a flywheel and an ignition system for an internal combustion engine of the hybrid vehicle, which addresses one or more limitations stated above.

SUMMARY OF THE INVENTION
[006] In one aspect, a flywheel for an ignition system of a hybrid vehicle is disclosed. The flywheel includes a shaft member coupled to a crankshaft disposed in a crankcase of an internal combustion engine. A plurality of wing members extend radially from the shaft member, wherein at least one of the plurality of wing members is defined with one or more pip members. The one or more pip members interact with a pulsar coil of the ignition system for enabling a control unit in the vehicle to determine an engine speed and/or a position of the crankshaft in the internal combustion engine.
[007] In an embodiment, each of the plurality of wing members is defined with a mounting provision for receiving a centrifugal fan. In an embodiment, each of the plurality of wing members is a triangular shaped wing member.
[008] In an embodiment, the at least one wing member having the one or more pip members includes a slot for mass balancing and reducing torsional vibrations in the flywheel.
[009] In an embodiment, the shaft member includes a hollow boss having an internal key slot for engagement with the crankshaft.
[010] In an embodiment, the flywheel is mounted on a right-hand side of the crankcase for providing idling stability.
[011] In an embodiment, the flywheel is manufactured via a sheet metal material.
[012] In an embodiment, each of the one or more pip members is an L-shaped protrusion.
[013] In another aspect, an internal combustion engine for the hybrid vehicle is disclosed. The internal combustion engine includes an ignition system having at least one battery disposed in the vehicle and coupled to a starter motor mounted on a crankcase of the internal combustion engine. The at least one battery is adapted to operate the starter motor for starting the internal combustion engine. The flywheel is mounted onto the crankcase and positioned proximal to a pulsar coil. The flywheel includes the shaft member coupled to the crankshaft disposed in the crankcase. The plurality of wing members extend radially from the shaft member, wherein at least one of the plurality of wing members is defined with one or more pip members. The one or more pip members interact with the pulsar coil of the ignition system for enabling a control unit in the vehicle to determine an engine speed and/or a position of the crankshaft in the internal combustion engine.
[014] In an embodiment, the at least one battery is coupled to a battery module of the vehicle. The battery module is adapted to charge the at least one battery.
[015] In an embodiment, the at least one battery is coupled to electrical components of the vehicle. The at least one battery is adapted to selectively power the electrical components.
[016] In an embodiment, the hybrid vehicle is provided. The vehicle includes the internal combustion engine mounted onto a frame member. The at least one battery is adapted to operate the starter motor for starting the internal combustion engine. The flywheel is mounted onto the crankcase and positioned proximal to a pulsar coil. The flywheel includes the shaft member coupled to the crankshaft disposed in the crankcase. The plurality of wing members extend radially from the shaft member, wherein at least one of the plurality of wing members is defined with one or more pip members. The one or more pip members interact with the pulsar coil of the ignition system for enabling a control unit in the vehicle to determine an engine speed and/or a position of the crankshaft in the internal combustion engine.

BRIEF DESCRIPTION OF THE DRAWINGS
[017] 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 schematic view of a hybrid vehicle, in accordance with an embodiment of the present invention.
Figure 2 is a perspective view of the vehicle depicting a frame member and components mounted thereon, in accordance with an embodiment of the present invention.
Figure 3 is a side view of the vehicle depicting the frame member and components mounted thereon, in accordance with an embodiment of the present invention.
Figure 4 is a schematic view of an internal combustion engine, in accordance with an embodiment of the present invention.
Figure 5 is a rear view of the internal combustion engine, in accordance with an embodiment of the present invention.
Figure 6 is a sectional view of the internal combustion engine, in accordance with an embodiment of the present invention.
Figure 7 is an exploded view of a flywheel of the internal combustion engine, in accordance with an embodiment of the present invention.
Figure 8 is a partial exploded view of the internal combustion engine, in accordance with an embodiment of the present invention.
Figure 9 is a top view of the flywheel, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[018] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder.
[019] Figure 1 illustrates a schematic view of a hybrid vehicle 200, in accordance with an embodiment of the present invention. As an example, the hybrid vehicle 200 is a scooter type vehicle. The vehicle 200 has a transmission system (not shown) including combination of an internal combustion engine 202 and a starter motor 232 (for e.g. as shown in Figure 4) as a prime mover, that is disposed behind a floorboard 210 and below a seat assembly 212 and/or a storage bin (not shown). In an embodiment, the transmission system includes electric motor or internal combustion engine 202 as the prime mover as per design feasibility and requirement. The vehicle 200 has a front wheel 214, a rear wheel 216 and a frame member 218 (as shown in Figures 2 and 3).
[020] A head pipe (not shown) connects to the frame member 218. The head pipe supports a steering shaft (not shown) and a front suspension (not shown) attached to the steering shaft through a lower bracket (not shown). The front suspension supports the front wheel 214. The upper portion of the front wheel 214 is covered by a front fender 220 mounted to the front suspension. In an embodiment, the front fender 220 is movable along with the front wheel 214, during travel over undulations on a road surface. A handlebar 222 is fixed to upper bracket (not shown) and can rotate about the steering shaft for turning the vehicle 200. A headlight (not shown) and an instrument cluster 224 is arranged on an upper portion of the head pipe.
[021] Further, a rear suspension (not shown) is provided to the rear wheel 216 for dampening the vibrations induced during travel of the vehicle 200 over undulations on the road surface. A taillight unit 226 is disposed at the end of the vehicle 200 and at the rear of the seat assembly 212. A grab rail 228 is also provided for facilitating the grip and/or balance to a rider on the vehicle 200 during movement. The rear wheel 216 is arranged below the seat assembly 212 and adapted to receive the motive force from the prime mover. A suitable transmission assembly is provided for transferring the drive force from the prime mover onto the rear wheel 216 for driving the vehicle 200. In an embodiment, the driving force of the internal combustion engine 202 is transmitted through a chain drive [not shown] or a belt drive [not shown]. A rear fender 230 is disposed above the rear wheel 216. An exhaust pipe (not shown) is also provided for the Internal combustion engine 202, that extends therefrom towards the rear end of the vehicle 200.
[022] Referring to Figures 2-4 in conjunction with Figure 1, an ignition system is provided to the internal combustion engine 202. The ignition system is adapted to start the internal combustion engine 202. The ignition system includes at least one battery 234 coupled to the starter motor 232 (as shown in Figure 4) mounted on a crankcase 206 (shown in Figure 4). In an embodiment, the at least one battery 234 is mounted on a head pipe of the vehicle 200. The at least one battery 234 is adapted to operate the starter motor 232 for starting the internal combustion engine 202. In an embodiment, the at least one battery 234 supplies power to the starter motor 232, which in-turn cranks the internal combustion engine 202 for starting. The at least one battery 234 is also coupled to electrical accessories of the vehicle 200 and thus adapted to manage the electrical load requirements in the vehicle 200.
[023] Further, a battery module 238 which is coupled to an alternator or generator (not shown) is coupled to the at least one battery 234. The battery module 238 is adapted to charge the at least one battery 234, for ensuring that the at least one battery 234 is capable of operating the electrical accessories of the vehicle 200. Such a construction mitigates the requirement of a stator or magneto assembly for charging the battery 234 in the ignition system of the internal combustion engine 202. Consequently, the weight and size of the internal combustion engine 202 is reduced, inherently improving the performance and fuel economy of the vehicle 200.
[024] Referring to Figure 4, the internal combustion engine 202 includes a flywheel 100 mounted onto the crankcase 206 and positioned proximal to a pulsar coil 208 (for e.g. as shown in Figure 7). The pulsar coil 208 acts as a detector and is adapted to monitor rotation of the flywheel 100. The description pertaining to the flywheel 100 is provided in detail in description pertaining to figures 6-9.
[025] Referring to Figure 6, the flywheel 100 mounted onto the internal combustion engine 202 is depicted. The flywheel 100 is adapted to be configured with a lower moment of inertia, thereby reducing the dissipation or usage of braking torque during operation of the vehicle 200 and/or internal combustion engine 202. In the present embodiment, the flywheel 100 is mounted on a right-hand side 206a (for e.g. as shown in Figure 4) of the crankcase 206 for providing idling stability to the internal combustion engine 202. In an embodiment, the flywheel 100 can be mounted on a left-hand side 206a (not shown) of the crankcase 206 for providing idling stability to the internal combustion engine 202, as per design feasibility and requirement.
[026] Referring to Figure 7 in conjunction with Figure 6, the flywheel 100 includes a shaft member 102 coupled to a crankshaft 204 disposed in the crankcase 206 (as shown in Figures 5 and 6). In an embodiment, the shaft member 102 is coupled to the crankshaft 204 via conventional coupling means such as a flange coupling, rigid coupling and the like as per design feasibility and requirement. In the present embodiment, the shaft member 102 includes a hollow boss 112a having an internal key slot 112b for engagement with the crankshaft 204 (for e.g. as shown in Figure 8).
[027] A plurality of wing members 104 extend radially from the shaft member 102. The wing members 104 provide the required momentum or stores the required rotational energy for ensuring smooth operation of the internal combustion engine 202, consequently the vehicle 200. In an embodiment, the shape and configuration of the wing members 104 is selected as per design feasibility and requirement. In the present embodiment, the wing members 104 are triangular in shape.
[028] Further, at least one of the plurality of wing members 104 is defined with one or more pip members 106. The one or more pip members 106 are adapted to extend towards the pulsar coil 208 and interact with the pulsar coil 208. The pulsar coil 208 is coupled to a control unit 236 (for e.g. as shown in Figures 2 and 3), and thus the interaction between the pulsar coil 208 and the wing members 104 is provided to the control unit 236. The control unit 236 based on the signals received from the pulsar coil 208, determines an engine speed and/or a position of the crankshaft 204.
[029] In an embodiment, the pulsar coil 208 interacts with the flywheel 100, by monitoring number of occasions in which the wing members 104 rotate or move past the pulsar coil 208. In another embodiment, the pulsar coil 208 provides information to the control unit 236 via electrical pulses.
[030] In an embodiment, the one or more pip members 106 is a pin-like protrusion extending laterally from each of the wing members 104. In the present embodiment, the one or more pip members 106 is a protrusion corresponding to the peripheral surface of each of the wing members 104, and thus conforming to an L-shaped protrusion (for e.g. as shown in Figure 9) of the wing member 104 (when viewed from a top side of the flywheel 100). Alternatively, the shape and configuration of each of the one or more pip members 106 as per design feasibility and requirement.
[031] Further, the wing member 104 including the one or more pip members 106 is defined with a slot 110. The dimensions and/or configuration of the slot 110 is selected for ensuring mass balancing and thereby reducing torsional vibrations in the flywheel 100. As such, the weight gain of the wing member 104 including the pip member 106 is balanced due to the slot 110. In the present embodiment, the slot 110 is of a rectangular shape.
[032] Furthermore, each of the plurality of wing members 104 is defined with a mounting provision 108 for receiving a centrifugal fan (not shown), wherein the centrifugal fan is adapted to facilitate airflow over the internal combustion engine 202 for ensuring operation in optimal thermal conditions. In the present embodiment, the mounting provision 108 is a mounting boss (as shown in Figure 7) enabling mounting of the centrifugal fan. As such, the centrifugal fan is fastened onto the mounting boss. In another embodiment, the mounting provision 108 is a projection, a protrusion or any other member as per design feasibility and requirement. Accordingly, the centrifugal fan is mounted onto the mounting provision 108 as per design feasibility and requirement.
[033] In an embodiment, the flywheel 100 is made of a sheet metal material. Accordingly, the wing members 104, the one or more pip members 106 and the mounting provision 108 are made of sheet metal material. In an embodiment, wing members 104, the one or more pip members 106 and the mounting provision 108 are made of material as per design feasibility and requirement in the internal combustion engine 202.
[034] Advantageously, the present invention provides a flywheel 100 mounted on one of the sides of the internal combustion engine 202, thereby enhancing idling stability. Also, the flywheel 100 is configured with one or more pips 106 for interaction with the pulsar coil 208, mitigating the need for a stator. Additionally, due to the configuration of the flywheel 100 and the at least one battery 234 in the ignition system, the requirement of magneto assembly is mitigated, thereby reducing overall weight of the internal combustion engine 202. Consequently, improving operational efficiency, fuel economy and reduction of emission in the internal combustion engine 202. Additionally, the flywheel 100 is configured with wing members 104 having the slot 110, which ensures uniform weight in each of the wing members 104, thereby preventing rotational imbalance in the flywheel 100. Also, reduction in weight also reduces the cost involved in manufacturing, thereby making the flywheel 100 inexpensive.
[035] 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
100 - Flywheel
102 - Shaft member
104 - Wing members
106 - Pip members
108 - Mounting provision
110 - Slot on the wing member
112a - Hollow boss
112b - Internal key slot
200 - Hybrid vehicle
202 - Internal combustion engine
204 - Crankshaft
206 - Crankcase
206a - Right-hand side of crankcase
208 - Pulsar coil
210 - Floorboard
212 - Seat assembly
214 - Front wheel
216 - Rear wheel
218 - Frame member
220 - Front fender
222 - Handle bar
224 - Instrument cluster
226 - Taillight unit
228 - Grab rail
230 - Rear fender
232 - Starter motor
234 - Battery
236 - Control unit
238 - Battery module