Claims:WE CLAIM:

1. An internal combustion engine (100) for a vehicle (10), comprising:
a crankcase (110);
a cover clutch (120) attached to the crankcase (110), the cover clutch (120) having an inner face along which oil travels in the crankcase (110);
an oil inlet (130) provided on the cover clutch (120) configured for allowing entry of oil in the crankcase (110);
an oil outlet (140) provided on the cover clutch (120) configured for allowing exit of oil from the crankcase (110);
an oil flow path (150) defined between the oil inlet (130) and the oil outlet (140), such that the oil flow path (150) extends along the inner face of the cover clutch (120) in a staggered manner, the oil flow path (150) having a crankshaft entry portion (160) from where the oil moves towards a crankshaft; and
an oil bypass groove (170) provided between the oil inlet (130) and the crankshaft entry portion (160) to allow direct flow of oil between the oil inlet (130) and the crankshaft entry portion (160), thereby decreasing drop in oil pressure from the oil inlet (130) to the crankshaft entry portion (160).

2. The internal combustion engine (100) as claimed in claim 1, wherein the oil flow path (150) has a first predefined width (W1) and a first predefined depth (D1).

3. The internal combustion engine (100) as claimed in claim 1, wherein the oil bypass groove (170) has a second predefined width (W2) and a second predefined depth (D2).

4. The internal combustion engine (100) as claimed in claims 3 and 4, wherein the second predefined width (W2) is lower than the first predefined width (W1), and the second predefined depth (D2) is lower than the first predefined depth (D1).

5. The internal combustion engine (100) as claimed in claim 3, wherein the first predefined width (W1) is 4.7 mm and the first predefined depth (D1) is 5 mm.

6. The internal combustion engine (100) as claimed in claim 4, wherein the second predefined width (W2) is 2 mm and the second predefined depth (D2) is 2 mm.

7. A saddle type vehicle (10), comprising:
an internal combustion engine (100) having a crankcase (110);
a cover clutch (120) attached to the crankcase (110), the cover clutch (120) having an inner face along which oil travels in the crankcase (110);
an oil inlet (130) provided on the cover clutch (120) configured for allowing entry of oil in the crankcase (110);
an oil outlet (140) provided on the cover clutch (120) configured for allowing exit of oil from the crankcase (110);
an oil flow path (150) defined between the oil inlet (130) and the oil outlet (140), such that the oil flow path (150) extends along the cover clutch (120) in a staggered manner, the oil flow path (150) having a crankshaft entry portion (160) from where the oil moves towards a crankshaft; and
an oil bypass groove (170) provided between the oil inlet (130) and the crankshaft entry portion (160) to allow direct flow of oil between the oil inlet (130) and the crankshaft entry portion (160), thereby decreasing drop in oil pressure from the oil inlet (130) to the crankshaft entry portion (160).

Dated this 28th day of January 2022

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 for a vehicle.

BACKGROUND OF THE INVENTION
[002] In conventional saddle type vehicles, engine oil is used for lubrication as well as a cooling medium. The lubricating properties of the oil get modified due to excessive heat and this results in the drop in the engine performance and engine durability. Generally, the engine is force cooled at the top portion, namely a cylinder head and cylinder block, where combustion takes place. However, rate of heat transfer at the combustion zone is not very effective. Generally, a separate oil cooling arrangement, like radiator or oil cooler may be used for cooling the oil. This provision of radiator or oil cooler results in an increase in the size of the system and also an increase in the part count. Also, additional load is added to the engine system which affects the performance.
[003] In addition to the heat of the combustion in the engine, heat is also generated by mechanical parts and frictional contacts, which further increase the requirement of cooling the engine. In the conventional vehicles where the regular flow path i.e. zigzag is implemented for oil cooling, issues such as choking in flow path, oil pressure increase due to sharp turns, leading to leaking are commonplace. In such systems, the engine oil may not reach the target positions within the engine, thus affecting durability of the engine and leading to mechanical failure.
[004] To maintain the oil pressure, in the conventional saddle type vehicles, the oil path is connected with an oil pump and fins are provided outside the flow path. However, the cooling of engine oil in such systems is not effective enough to meet the cooling requirements, especially as the fins are not aligned with flow of air. Space constraints limit the number of fins that can be provided for increasing the cooling.
[005] In other saddle type vehicles, a separate element is provided which is mounted below the headlamp, wherein the element has two additional tubes for inlet and outlet of air. However, such systems are associated with a high cost and add to the engine weight.
[006] Thus, there is a need in the art for an internal combustion engine for a vehicle which addresses the aforementioned problems.

SUMMARY OF THE INVENTION
[007] In an aspect, the present invention is directed towards an internal combustion engine for a vehicle having a crankcase and a cover clutch attached to the crankcase. The cover clutch has an inner face along which oil travels in the crankcase. An oil inlet is provided on the cover clutch, and is configured for allowing entry of oil in the crankcase. An oil outlet is provided on the cover clutch, and is configured for allowing exit of oil from the crankcase. An oil flow path is defined between the oil inlet and the oil outlet, such that the oil flow path extends along the inner face of the cover clutch in a staggered manner. The oil flow path has a crankshaft entry portion from where the oil moves towards a crankshaft. An oil bypass groove is provided between the oil inlet and the crankshaft entry portion to allow direct flow of oil between the oil inlet and the crankshaft entry portion, thereby decreasing drop in oil pressure from the oil inlet to the crankshaft entry portion.
[008] In an embodiment of the invention, the oil flow path has a first predefined width and a first predefined depth. In an embodiment, the first predefined width is 4.7 mm and the first predefined depth is 5 mm.
[009] In another embodiment of the invention, the oil bypass groove has a second predefined width and a second predefined depth. In an embodiment, the second predefined width is 2 mm and the second predefined depth is 2 mm.
[010] In a further embodiment of the invention, the second predefined width is lower than the first predefined width, and the second predefined depth is lower than the first predefined depth.
[011] In another aspect, the present invention is directed towards a saddle type vehicle having an internal combustion engine. The internal combustion engine has a crankcase and a cover clutch attached to the crankcase. The cover clutch has an inner face along which oil travels in the crankcase. An oil inlet is provided on the cover clutch, and is configured for allowing entry of oil in the crankcase. An oil outlet is provided on the cover clutch, and is configured for allowing exit of oil from the crankcase. An oil flow path is defined between the oil inlet and the oil outlet, such that the oil flow path extends along the inner face of the cover clutch in a staggered manner. The oil flow path has a crankshaft entry portion from where the oil moves towards a crankshaft. An oil bypass groove is provided between the oil inlet and the crankshaft entry portion to allow direct flow of oil between the oil inlet and the crankshaft entry portion, thereby decreasing drop in oil pressure from the oil inlet to the crankshaft entry portion.

BRIEF DESCRIPTION OF THE DRAWINGS
[012] 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 illustrates a left side view of an exemplary saddle type vehicle in accordance with an embodiment of the invention.
Figure 2 illustrates a sectional side view of an internal combustion engine, in accordance with an embodiment of the invention.
Figure 3 illustrates a sectional perspective view of the internal combustion engine, in accordance with an embodiment of the invention.
Figure 4 illustrates an exploded view of the internal combustion engine, in accordance with an embodiment of the invention.
Figure 5 illustrates an oil bypass groove of the internal combustion engine, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION
[013] The present invention relates to an internal combustion engine for a vehicle. More particularly, the present invention relates to an internal combustion engine for a saddle type vehicle.
[014] Figure 1 illustrates an exemplary saddle type vehicle 10, in accordance with an embodiment of the invention. The saddle type vehicle 10 comprises an internal combustion engine 100 that is vertically disposed. In an embodiment, the IC engine 100 is a single-cylinder type IC engine. The saddle type vehicle 10 further comprises a front wheel 14, a rear wheel 16, a frame member (not shown), a seat 18 and a fuel tank 20. The frame member includes a head pipe 22, a main frame, rear down tubes, and seat rails (not shown). The head pipe 22 supports a steering shaft (not shown) and two telescopic front suspensions 26 (only one shown) attached to the steering shaft through a lower bracket (not shown). The two telescopic front suspensions 26 support the front wheel 14. The upper portion of the front wheel 14 is covered by a front fender 28 mounted to the lower portion of the telescopic front suspension 26 at the end of the steering shaft. A handlebar 30 is fixed to upper bracket not shown and can rotate to both sides. A head light 32, a visor guard (not shown) and instrument cluster (not shown) is arranged on an upper portion of the head pipe 22. The frame member comprises a down tube 44 that may be located in front of the IC engine 100 and extends slantingly downward from head pipe 22. The main frame of the frame member is located above the IC engine 100 and extends rearward from head pipe 22. The IC engine 100 is mounted at the front to the down tube 44 and a rear of the IC engine 100 is mounted at the rear portion of the main frame. In an embodiment, the IC engine 100 is mounted vertically, with a cylinder block extending vertically above a crankcase 110 (shown in Figure 2). In an alternative embodiment, the IC engine 100 is mounted horizontally with the cylinder block extending horizontally forwardly from the crankcase 110. In an embodiment, the cylinder block is disposed rearwardly of the down tube 44.
[015] The fuel tank 20 is mounted on the horizontal portion of the main frame. Seat rails are joined to main frame and extend rearward to support the seat 18. A rear swing arm 34 is connected to the frame member to swing vertically, and a rear wheel 16 is connected to rear end of the rear swing arm 34. Generally, the rear swing arm 34 is supported by a mono rear suspension 36 or through two suspensions 36 on either side of the saddle type vehicle 10 (as illustrated in the present embodiment). A taillight unit 33 is disposed at the end of the saddle type vehicle 10 and at the rear of the seat 18. A grab rail 37 is also provided on the rear of the seat rails. The rear wheel 16 arranged below seat 18 rotates by the driving force of the IC engine 100 transmitted through a chain drive (not shown) from the IC engine 100. A rear fender 38 is disposed above the rear wheel 16.
[016] Further, an exhaust pipe (not shown) of the vehicle 10 extends vertically downward from the IC engine 100 up to a point and then extends below the IC engine 100, longitudinally along the vehicle length before terminating in a muffler (not shown). The muffler is typically disposed adjoining the rear wheel 16.
[017] Figure 2 illustrates a sectional view of the internal combustion engine 100. As illustrated in Figure 2, and further illustrated in Figure 3 and Figure 4, the IC engine 100 has a cover clutch 120 attached to the crankcase 110. The cover clutch 120 is configured for supporting and covering a clutch assembly of the engine 100. In an embodiment, the cover clutch 120 is disposed on a right hand side of the crankcase 110. In an alternative embodiment, the cover clutch 120 is disposed on a left hand side of the crankcase 110.
[018] The cover clutch 120 has an inner face along which oil travels in the crankcase 110. The oil travelling along the inner face of the cover clutch 120 defines an internal arrangement wherein heated oil from the cylinder block is transmitted to the inner face of the cover clutch 120. Since an outer face of the cover clutch 120 is exposed to the atmosphere, as the vehicle moves, atmospheric air travels over the outer face of the clutch cover 120, thereby cooling the oil traveling along the inner face of the cover clutch 120. The cooled oil is then transmitted back into the cylinder block.
[019] To facilitate this internal arrangement for cooling of the oil, the engine 100 of the present invention comprises an oil inlet 130 through which the oil enters in the crankcase 110. The oil inlet 130 is provided on the cover clutch 120 and the oil inlet 130 is configured for allowing entry of oil in the crankcase 110. The engine 100 further has an oil outlet 140 through which the oil exits the crankcase 110 towards the cylinder block. The oil outlet 140 is provided on the cover clutch 120 and the oil outlet 140 is configured for allowing exit of oil from the crankcase 110. An oil flow path 150 is defined between the oil inlet 130 and the oil outlet 140. The oil flow path 150 is defined such that the oil flow path 150 extends along the inner face of the cover clutch 120 in a staggered manner. The provision of the oil flow path 150 in a staggered manner along the inner face of the cover clutch 120 ensures that the oil covers a large distance between the oil inlet 130 and the oil outlet 140, thereby allowing greater time for which the oil is in contact with the inner face of the cover clutch 120, hence ensuring maximum cooling. In an embodiment, the oil flow path 150 has a first predefined width (W1) and a first predefined depth (D1). In an embodiment, the first predefined width (W1) is 4.7 mm and the first predefined depth (D1) is 5 mm.
[020] As illustrated in Figure 2 and Figure 3, the oil flow path 150 has a crankshaft entry portion 160 from where the oil moves towards a crankshaft (not shown), thereby providing lubrication to moving mechanical parts of the engine 100 such as the crankshaft, and absorbing mechanical and frictional heat generated by the crankshaft and other moving parts.
[021] The internal combustion engine 100 further has an oil bypass groove 170. The oil bypass groove 170 is provided between the oil inlet 130 and the crankshaft entry portion 160. Provision of the oil bypass groove 170 allows direct flow of oil between the oil inlet 130 and the crankshaft entry portion 160. This means that in addition to the oil travelling in the oil flow path 150 between the oil inlet 130 and the oil outlet 140, a portion of the oil is also directed in the oil bypass groove 170 for direct flow between the oil inlet 130 and the crankshaft entry portion 160. This direct flow of oil between the oil inlet 130 and the crankshaft entry portion 160 results in a decrease in the drop in oil pressure from the oil inlet 130 to the crankshaft entry portion 160. This ensures that adequate oil is supplied to the crankshaft entry portion 160, and thus to the crankshaft and other mechanical components of the engine 100 under all running conditions.
[022] In an embodiment, the oil bypass groove 170 has a second predefined width (W2) (shown in Figure 5) and a second predefined depth (D2) (shown in Figure 5). In an embodiment, the second predefined width (W2) is lower than the first predefined width (W1), and the second predefined depth (D2) is lower than the first predefined depth (D1). Such dimension ensure that a major portion of the oil still travels along the oil flow path 150, and only a minor portion of the oil is directed towards the oil bypass groove 170, thus ensuring that the provision of the oil bypass groove 170 does not hamper the cooling of the oil along the inner face of the cover clutch 120.
[023] In an embodiment, the second predefined width (W1) is 2 mm and the second predefined depth (D2) is 2 mm.
[024] Advantageously, the present invention provides an internal combustion engine for a vehicle in which the pressure drop in oil between the oil inlet and the crankshaft entry portion is lower, thus ensuring adequate oil supply and discharge to the crankshaft and other engine moving components.
[025] with a more efficient cooling of the engine oil, maintaining the oil temperatures at a lower level, thereby prolonging life of the engine oil itself, and preventing engine moving components from damage. A more efficient cooling of the engine oil is achieved by minimal constructional changes in the existing constructional arrangement. Furthermore, the present invention provides a cost-effective solution for providing cooling of engine oil.
[026] Further, the internal combustion engine of the present invention ensures that no additional components need to be added to the internal combustion engine to ensure efficient cooling and adequate supply and discharge of the oil across the lubrication system of the engine.
[027] 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.