WO2010035288A1

WO2010035288A1 - Two-stroke compression ignition engine

Info

Publication number: WO2010035288A1
Application number: PCT/IN2009/000531
Authority: WO
Inventors: Venugopalan Pattabiraman; Vinay Chandrakant Harne
Original assignee: Tvs Motor Company Limited
Priority date: 2008-09-29
Filing date: 2009-09-29
Publication date: 2010-04-01
Also published as: AP3647A; AP2011005643A0

Abstract

The subject matter described herein is directed to a two-stroke compression ignition engine (200) for a two or three wheeled vehicle. The two-stroke compression ignition engine (200) includes a fuel injection system (105) having a fuel pump (115) mounted on a crankcase (220). The fuel pump (115) pressurizes fuel received from a fuel tank (110) and delivers the pressurized fuel to an accumulator (120). A fuel filter (112) provided between the fuel pump (115) and the fuel tank (110) facilitates filtration of the fuel. Further, the accumulator (120) is configured to route the pressurized fuel to one or more injectors (125). The fuel injection system (105) aids for a compact and a light weight engine.

Description

TWO-STROKE COMPRESSION IGNITION ENGINE

TECHNICAL FIELD

The subject matter described herein, in general, relates to internal combustion engines and in particular, relates to two-stroke compression ignition engines.

BACKGROUND

Conventionally, internal combustion (IC) engines are used in industrial, vehicular and marine applications. The IC engines can be mainly classified into two categories, two-stroke and four-stroke, based on the number of strokes per working cycle. A two-stroke engine has a power stroke every revolution of the crankshaft as opposed to a four-stroke engine, which has a power stroke every two revolutions of the crankshaft. Due to this reason, a two-stroke engine can generate power greater than a four stroke engine of the same size.

IC engines can be further classified, based on the type of ignition used, into compression ignition or spark ignition engines. Typically, the compression ignition engines use diesel fuel for combustion and are referred to as diesel engines. On the other hand, the spark ignition engines use petrol as fuel and are referred to as petrol engines. Diesel engines, when used in vehicles, provide higher mileage than petrol engines as diesel engines have better thermal efficiency and also diesel has a higher energy density, i.e., the energy extracted from a given volume of diesel is greater than the energy extracted from the same volume of petrol (gasoline). Additionally, diesel engines are more rugged and reliable as compared to petrol engines.

Although diesel provides better fuel efficiency than petrol, and two-stroke engines are capable of generating more power than four-stroke engines, the use of two-stroke diesel engines is limited to low speed applications such as marine engines, locomotive engines and stationary engines, usually having a large cylinder bore. Further, the use of diesel engines in vehicles is restricted to four-wheeled vehicles. The reasons which hamper the use of diesel engines in two-wheeled or three-wheeled vehicles include large size of the engine for a desired power output, high vibrations of the engine, high emissions, low power-to-weight ratio and high noise levels of such engines as compared to a typical petrol engine. Further, strict emissions norms and high maintenance cost associated with the two-stroke diesel engines also restrict their application in vehicles. SUMMARY

The subject matter described herein is directed to a two-stroke compression ignition engine. The two-stroke compression ignition engine includes one or more cylinders each having a piston and a fuel injection system. The fuel injection system includes a fuel pump disposed on a crankcase of the two-stroke compression ignition engine. The fuel pump pressurizes fuel received from a fuel tank and delivers the pressurized fuel to an accumulator.

Also, a fuel filter is disposed between the fuel pump and the fuel tank to enable filtration of the fuel provided to the accumulator from the fuel pump. The fuel filter receives fuel from the fuel tank and routes the filtered fuel to the fuel pump. The accumulator stores the pressurized fuel and delivers the pressurized fuel to one or more injectors located on the cylinder head. hi one embodiment of the subject matter described herein, a two-wheeled or a three- wheeled vehicle incorporating the aforementioned two-stroke compression ignition engine is described. Further, the described fuel injection system aids for a fuel efficient, less noisy, and environment friendly engine.

These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This Summary is provided to introduce a selection of concepts in a simplified form. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF DRAWINGS

The above and other features, aspects, and advantages of the subject matter will become better understood with regard to the following description, appended claims, and accompanying drawings where:

Fig. 1 illustrates a fuel flow diagram of an exemplary fuel injection system, according to an embodiment of the present subject matter.

Fig. 2a illustrates a cross sectional view of an exemplary two-stroke compression ignition engine, according to an embodiment of the present subject matter. Fig. 2b illustrates a fuel filter of the fuel injection system of Fig.2a, according to an embodiment of the present subject matter.

Fig. 3a illustrates a perspective view of a cylinder head of the two-stroke compression ignition engine of Fig.2a, according to an embodiment of the present subject matter. Fig. 3b illustrates mounting of an accumulator and an injector on the cylinder head of

Fig. 3a, according to an embodiment of the present subject matter.

DETAILED DESCRIPTION

The subject matter described herein relates to a two-stroke compression ignition engine and a two-wheeled or a three-wheeled vehicle incorporating the two-stroke compression ignition engine.

The two-stroke compression ignition engine includes a fuel injection system for delivering fuel to one or more cylinders of the two-stroke compression ignition engine. The fuel injection system includes a fuel tank, which is hydraulically connected to a fuel pump mounted on a crankcase. A fuel filter is disposes in between the fuel tank and the fuel pump. The fuel from an outlet of the fuel tank is filtered using the fuel filter and is supplied to the fuel pump.

In one embodiment, the fuel tank is placed above the fuel pump such that the fuel flows from the fuel tank to the fuel pump under the influence of gravity. The fuel pump pressurizes the fuel to an elevated pressure and supplies the pressurized fuel to an accumulator. The accumulator may be mounted on a cylinder head. The fuel pump and the accumulator can be placed on the same side of the engine. The accumulator stores and maintains the high pressure of the fuel and delivers the same to one or more injectors via fuel pipes. In one embodiment, the accumulator and the injector are mounted on a cylinder head.

The injectors can be mounted vertically at a position such the position is substantially aligned to a central axis of the cylinder head. The mounting can be done using a clamping arrangement.

Such a two-stroke compression ignition engine is fuel efficient and compact, and can be used as a engine having a small bore, thereby making the engine suitable for use in light weight automobiles such as two-wheeled or three-wheeled vehicles. Although the two-stroke compression ignition engine system of the present subject matter has been described with respect to a two-wheeled or three-wheeled vehicle, it would be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. For example, the two-stroke compression ignition engine may be implemented in gen-sets, lawnmowers and so on.

Fig. 1 illustrates a fuel flow diagram 100 for an exemplary fuel injection system 105, according to an embodiment of the present subject matter. The fuel injection system 105 is implemented in a two-stroke compression ignition engine (shown in Fig.2) for a two-wheeled or three wheeled vehicle. In one embodiment, the fuel injection system 105 includes a fuel tank 110 for storing fuel such as diesel, and a fuel filter 112 provided at an outlet of the fuel tank 110. The fuel filter 112 receives fuel from the outlet of the fuel tank 110 and filters the fuel. The filtered fuel is then supplied to an inlet of the fuel pump 115. The filtered fuel is substantially free from abrasive particles that are filtered out by the fuel filter 112. The fuel pump 115 is mounted on a crankcase (not shown in the figure) of the two- stroke compression ignition engine and pressurizes the fuel received from the fuel tank 110. The pressurized fuel from the fuel pump 115 is conveyed to an accumulator 120. The accumulator 120 stores the pressurized fuel and maintains substantially constant pressure. In one implementation, the accumulator 120 may include a pressure sensor valve (shown in Fig.3) and a pressure regulator (shown in Fig.3) to maintain a constant pressure.

Further, the pressurized fuel from the accumulator 120 is routed to the injector(s) 125. The injector(s) 125 inject the pressurized fuel into a corresponding combustion chamber 130 at a predetermined timing during a combustion cycle. Fuel injection parameters such as the timing of injection, the number of injections per combustion cycle, and the quantity of fuel to be injected may be controlled by an electronic control unit (ECU) (not shown in the figures) of the vehicle. Further, the surplus fuel from the injector(s) 125 and the accumulator 120 is routed back to the fuel tank 110 as illustrated by fuel lines 135, thereby preventing any wastage of the fuel and maintaining the fuel pressure substantially constant.

Fig. 2a illustrates a cross sectional view of an exemplary two-stroke compression ignition engine 200, and Fig. 2b illustrates positioning of the fuel filter 112, according to an embodiment of the present subject matter, when used in a two-wheeled vehicle. In one embodiment, the two-stroke compression ignition engine 200, hereinafter interchangeably referred to as engine 200, is a naturally aspirated engine, thereby making the engine 200 compact and economical. The engine 200 has been explained with respect to a single cylinder engine; however it would be appreciated that the engine 200 can comprise multiple cylinders. As illustrated in Fig.2, the engine 200 includes a cylinder 205, a crankshaft 210, and the fuel injection system 105. In one implementation, the engine 200 is a small bore engine wherein the cylinder 205 may have a bore size of approximately 60 mm to 110 mm and particularly about 60 mm to 80 mm. The small bore size of the cylinder 205 makes it suitable for use in light weight and compact vehicles such as two-wheeled or three-wheeled vehicles. The cylinder 205 includes a piston 215 movably disposed inside the cylinder 205. The combustion chamber 130 is formed by a space inside the cylinder 205 defined by a cylinder head of the engine 200 and the piston 215. The fuel injection system 105 injects fuel inside the combustion chamber 130 at a predetermined timing of the combustion cycle. The fuel injection system 105 includes the fuel pump 115 that receives fuel from the fuel tank 110 (not shown in the figure). The fuel tank 110 may be equipped with a level sensor (not shown in the figures). The level sensor can be coupled to the ECU to determine fuel level in the fuel tank 110. The level sensor provides a signal to the ECU on sensing that the fuel level inside the fuel tank 110 is below a predetermined fuel level. The ECU in turn generates an alert to notify a user of the vehicle In one implementation, the ECU based on the signal from the level sensor may provide an alert signal indicating the distance, which can be in kilometres (kms), the vehicle can travel before all of the fuel is exhausted. Further, the ECU based on the signal from the level sensor and an additional selector can provide a "limp-home" mode that would enable the user to run the vehicle in a fuel saving mode. Such a provision can advantageously enable the user to reach to a nearest fuel station before all the fuel is consumed.

As aforementioned, the fuel from the fuel tank 110 may be fed to the fuel pump 115 through the fuel filter 112 that prevents abrasive materials from entering the fuel injection system 105. The fuel filter 112 can also be equipped with a mechanism for water separation. The fuel filter 112 is positioned in a compartment below the fuel tank 110 and above the inlet of the fuel pump 115. In another words, the fuel filter 112 is disposed in the space between an outlet of fuel tank 110 and the inlet of the fuel pump 115. Although, the positioning of the fuel filter 112 has been illustrated with respect to a two-wheeled vehicle, it would be appreciated that such a positioning may also be implemented for a three-wheeled vehicle, and also in a standalone internal combustion engine.

The fuel pump 115 may also be designed to facilitate self venting in situations when the engine 200 is started after a prolonged gap, after service or when the fuel is completely drained from the fuel tank 110. Thus, the fuel pump 115 bleeds out the entrapped air itself without the need of external devices and/or operations.

As illustrated in Fig. 2a, the fuel pump 115 is mounted on a crankcase 220 of the engine 200. Owing to the stiffness and the strength of the crankcase 220, the fuel pump 115 is capable of working at high pressures at all operating conditions of the engine 200. hi one embodiment, the fuel pump 115 is a mechanically driven pump and is driven by the crankshaft 210 using a cam mechanism. The cam mechanism includes a cam (not shown in the figures), such as an eccentric cam, located on the crankshaft 210 such that the fuel pump 115 is driven at the speed of the crankshaft 210. The cam cooperates with a plunger (not shown in the figures) of the fuel pump 115 in such a way that upon rotation, the cam imparts a reciprocating motion to the plunger, hi said embodiment, the rotational movement of the crankshaft 210 directly drives the fuel pump 115 without any intermediate components, thereby providing a compact engine.

Further, the fuel pump 115 provides the fuel at high pressures, for example, at pressures greater than 500 bars, as against conventional fuel pumps used for light weight vehicles. Consequently, the fuel breaks into small particles during injection and evenly mixes with the air, eventually reducing automotive pollution and fuel consumption. hi an embodiment, the fuel pump 115 is positioned such that fuel from the fuel tank 110 flows to the fuel pump 115 under the influence of gravity. For the purpose, the fuel pump 115 is positioned below the fuel tank 110. Thus, the fuel injection system 105 does not require a separate pump, commonly known as feed pump, for supplying fuel from the fuel tank 110 to the fuel pump 115. Such a positioning of the fuel tank 110 and the fuel pump 115 eliminates the need of the feed pump, generally provided at the suction side of a conventional fuel pump.

However, it would be appreciated that the described fuel injection system 105 is not to be limited by the gravity fed fuel pump 115. The fuel injection system 105 can also employ a conventional fuel pump arrangement for delivering fuel to the fuel pump 115. For example, the fuel injection system 105 may include a feed pump or low-pressure pump to deliver the fuel from the fuel tank 110 to a fuel injection pump or high-pressure fuel pump that pressurizes the fuel and delivers it to the accumulator 120.

In operation, the fuel tank 110 is hydraulically connected to the fuel pump 115 that delivers the pressurized fuel to the accumulator 120 such as a fuel rail. The fuel pump 115 and the accumulator 120 can be sized according to the pressure requirements of the engine 200.

The sizing may be determined based on the highest pressure required at any given engine speed considering the losses in the speed.

In one embodiment, the accumulator 120 and the fuel pump 115 are disposed on the same side of the vehicle. Due to such an arrangement, the length of the fuel pipes connecting the fuel pump 115 to the accumulator 120 and further connecting the accumulator 120 to the injector 125 is kept short. Shorter fuel pipes provide uniformity of pressure throughout the length of the fuel pipes and are structurally robust, providing enhanced safety to a rider of the vehicle.

In another embodiment, the accumulator 120 is cast integral with the fuel pump 115. In said embodiment, the accumulator 120 is in the form of a cavity in the body of the fuel pump 115. The fuel from the fuel pump 115 is delivered to the cavity through an internal path.

Further, the accumulator 120 can have a plurality of opening for positioning the pressure regulator valve and the pressure sensor. Further, one of the openings can form an outlet of the accumulator 120, which maybe connected to the injector 125. Further, the pressurized fuel from the accumulator 120 is supplied to the injector 125 that injects the pressurized fuel into the combustion chamber 130 through a nozzle 225. As mentioned before, parameters such as injection timing, injection duration and injection pressure for injector 125 can be controlled by the ECU.

In case of a multiple cylinder engine, the pressurized fuel from the accumulator 120 is routed to all the injector(s) 125. The ECU may include means for actuating each injector 125 individually at a predetermined timings and for a prescribed duration, according to the operating conditions of the engine 200. The surplus fuel from the injector 125 and the accumulator 120 is routed back to the fuel tank 110, thereby preventing wastage of fuel. In addition, an appropriate sealing of the return path at the outlet of the fuel pump 115 and sealing at the pressure regulator valve on the accumulator 120, is provided to avoid draining of the fuel during a shutdown of the engine 200. Such a provision enables quick pressure build-up on re-starting the engine 200. Further, the compact arrangement of the engine coupled with the high pressure of the fuel provides an efficient and cost-effective engine.

Fig. 3a illustrates a perspective view of the cylinder head 305 of the two-stroke compression ignition engine of Fig. 2a, and Fig. 3b illustrates mounting of the accumulator 120 and the injector 125, according to an embodiment of the present subject matter. In operation, the high pressure fuel from the fuel pump 115 is routed to the accumulator 120 through a first fuel pipe (not shown in the figure). The first fuel pipe connects a port of the fuel pump 115 to an inlet (not shown in the figure) of the accumulator 120. The accumulator 120 acts as a reservoir for the pressurized fuel to ensure that the pressurized fuel is available to the injector 125 as and when required. From an outlet 310 of accumulator 120, the fuel is supplied to the injector 125 by way of a second fuel pipe 315, leading from an outlet 320 of the accumulator 120 to the injector 125.

In one embodiment, the accumulator 120 may be mounted on the cylinder head 305 using a plurality of bolts 322. However, the accumulator 120 can also be mounted on a cylinder block housing the cylinder 205. Also, in case of a multi-cylinder engine, the engine 200 can have a common cylinder head and a common cylinder block for all the cylinders and the accumulator 120 may be mounted on the common cylinder head or the common cylinder block. Owing to such a mounting arrangement, the disassembly of the accumulator 120 for servicing purposes is simplified. Further, to ensure safety of the high pressure connections from the fuel pump 115 to the accumulator 120 and from the accumulator 120 to the injector 125, a shield (not shown in the fig.) can be provided around the fuel pump 115 and the accumulator 120.

The accumulator 120 may be mounted along a periphery of the cylinder head 305. hi one embodiment, the accumulator 120 has a tubular construction; however other shapes of the accumulator 120 for a required volume of fuel may also be provided, for example spherical shaped accumulator, larger diameter-shorter length cylindrical accumulator, etc. In one implementation of said embodiment, the accumulator 120 is a fuel rail and is positioned such that the accumulator 120 is substantially parallel to a longitudinal axis of the vehicle. In other words, the accumulator 120 extends substantially parallel to the length of the vehicle. Further, the accumulator 120 may also be mounted in any other suitable orientation. The orientation of the accumulator 120 can be based on appropriate location and orientation of the pressure sensor 325 and the pressure regulator valve 330 to provide efficient venting of fuel and to maintain a constant pressure in the accumulator 120. In one embodiment, the pressure sensor 325 and the pressure regulator valve 330 are positioned on the accumulator 120. The pressure sensor 325 senses the fuel pressure inside the accumulator 120 and provides a pressure value to the ECU. The ECU, in turn, regulates the pressure regulator valve 330 to maintain a constant pressure inside the accumulator 120 at all operating conditions of the engine 200. Thus, the accumulator 120 minimizes the pressure fluctuations in the fuel supplied by the fuel pump 115. The ECU may lower the fuel pressure inside the accumulator 120 depending on the operating conditions of the engine 200.

For example, when the ECU determines that the sensed fuel pressure is higher than a threshold pressure range for a particular operating condition, the pressure regulator valve 330 is opened to drain out surplus fuel from the accumulator 120 to the fuel tank 110. Due to the return of the surplus fuel from the accumulator 120, the fuel pressure inside the accumulator 120 is relieved and a substantially constant pressure is maintained. Thus, the pressure sensor 325 and the pressure regulator valve 330 maintain a substantially constant fuel pressure inside the accumulator 120 and provide easy venting of fuel in case the fuel pressure is higher than the threshold pressure range, thereby making it safe for use in the two-wheeled or the three- wheeled vehicles.

In an embodiment, the pressure sensor 325 is provided on the accumulator 120 and a metering valve (not shown in the figures) is provided at the inlet of the fuel pump 115. In said embodiment, instead of providing the pressure regulator valve 330 at a high pressure side i.e. on the accumulator 120, a metering valve is provided at a low pressure side i.e. at the inlet of the fuel pump 115. In such an embodiment, a constant pressure of the fuel is maintained by regulating the amount of fuel entering the fuel pump 115. The ECU controls the operation of the metering valve based on the pressure required for optimum operation of the engine 200 at a given instant of time and pressure sensed by the pressure sensor 325.

As mentioned previously, the pressurized fuel from the accumulator 120 is hydraulically connected to the injector 125. In one embodiment, the injector 125 is mounted on an opening, which is at the centre of the cylinder head 305. A clamping arrangement 340 can be provided to support the injector 125 at substantially right angle to the cylinder head 305. The clamping arrangement 340 substantially aligns the injector 125 to a central axis of the cylinder 205 or the cylinder head 305 mounted thereon. In other words, the clamping arrangement 340 clamps the injector such that a longitudinal axis of the injector 125 is aligned to a central axis of the cylinder 205. The clamping arrangement 340 includes a clamping bracket 345 resting around the wings (not shown in the figures) provided on the body of the injector 125. The clamping bracket 345 is held in position with the help of a clamping stud 350 and a support stud 355. The clamping stud 350 and the support stud 355 are screwed on the cylinder head 305. The support stud 355 has a tapered depression for receiving a mating ball provided at an end of the clamping bracket 345, other than the one which holds the injector 125. The swiveling of the mating ball in the tapered depression, and a nut and washer arrangement provided on the clamping stud 350 facilitates mounting of injectors of various heights. The height variations can be due a variety of reasons such as manufacturing tolerances of the injector 125, variations in seating height of the nozzle 225, on the cylinder head 125, and other tolerances which may stack up resulting in height variations. Further, the clamping arrangement 340 provides flexibility for easy dismounting of the injector 125 for servicing.

In one implementation, the injector 125 is a solenoid actuated injector and is activated when a programmed input from the ECU is received. However, any other type of injector known in the art may also be used, for example, a piezoelectric injector. The injector 125 injects the pressurized fuel inside the combustion chamber 130 through the nozzle 225. A tip 225 of the nozzle 225 has a plurality of orifices for injecting the pressurized fuel inside the combustion chamber 130. The orifices can be arranged radially on the tip 225. Owing to the pressure of the fuel and the described configuration of the orifices on the tip 225, spray- pattern of the injected fuel is substantially disc shaped i.e. the spray-pattern takes substantially the form of a flat disc. The spray-pattern has a conic angle of about 160° to 180°. Such a spray pattern provides efficient mixing of fuel and air.

Further, the injector 125 may produce multiple injections per combustion cycle at a predetermined timing. The pressurized fuel may be injected for short durations during the multiple injections. Additionally, small amounts of the fuel may be pilot injected into the combustion chamber 130 prior to the actual injection. The short multiple injections and the pilot injection of the fuel generate a smooth combustion cycle, thus reducing excess noise and vibrations associated with such engine types. The previously described versions of the subject matter and its equivalent thereof have many advantages, including those which are described below. The subject matter described herein provides a small bore, a compact and light weight two-stroke compression ignition engine, thereby making it suitable for use in two wheeled or three wheeled vehicles. Additionally, constant high pressure of the fuel maintained in an accumulator ensures that injected fuel is finely atomized and mixed evenly with the air, thereby leaving negligible unburned fuel and lowering exhaust emissions. Further, parameters such as the injection pressure, fuel quantity, and injection timings can be controlled electronically to promote complete and efficient combustion. This ensures low emissions, low vibrations and allows enhanced engine performance. While certain features of the claimed subject matter have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the claimed subject matter.

Claims

IAVe claim:

1. A two-stroke compression ignition engine (200) for a two-wheeled or three- wheeled vehicle, the two-stroke compression ignition engine (200) comprising:

at least one cylinder (205);

a piston (215) movably disposed inside the cylinder (205); and

a crankshaft (210) operably connected to the piston (215);

characterized in that,

a fuel injection system (105) provided to inject pressurized fuel into the cylinder (205), wherein the fuel injection system (105) comprises,

a fuel filter (112) connected to a fuel tank (110);

a fuel pump (115) to pressurize fuel received from the fuel tank (110) via the fuel filter (112), wherein the fuel pump (115) is mounted on a crankcase (220);

an accumulator (120) to receive the pressurized fuel from the fuel pump (115); and

at least one injector (125) to receive the pressurized fuel from the accumulator (120) for injecting the pressurized fuel in the cylinder (205).

2. The two-stroke compression ignition engine (200) as claimed in claim 1, wherein the accumulator (120) is a fuel rail, and wherein the fuel rail is positioned such that a longitudinal axis of the fuel rail is substantially parallel to a longitudinal axis of the vehicle.

3. A two-stroke compression ignition engine (200) for a two-wheeled or three- wheeled vehicle, the two-stroke compression ignition engine (200) comprising: at least one cylinder (205);

a piston (215) movably disposed inside the cylinder (205); and

a crankshaft (210) operably connected to the piston (215);

characterized in that,

a fuel pump (115) to pressurize fuel received from a fuel tank (110), wherein the fuel pump (115) is mounted on a crankcase (220);

an accumulator (120) to receive the pressurized fuel from the fuel pump (115), wherein the accumulator (120) is substantially parallel to a longitudinal axis of the vehicle; and

4. The two-stroke compression ignition engine (200) as claimed in claim 3, wherein the two-stroke compression ignition engine (200) further comprises a fuel filter (112) to receive fuel from the fuel tank (110) for filtering the received fuel and to deliver the filtered fuel to the fuel pump (115).

5. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or 3, wherein the fuel pump (115) is disposed below a fuel tank (110) such that the fuel from the fuel tank (110) is delivered to the fuel pump (115) by gravity feed.

6. The two-stroke compression ignition engine (200) as claimed any of the claims 1 or 3, wherein the cylinder (205) has a bore size ranging from about 60 mm to about 110 mm.

7. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or 3, wherein the fuel pump (115) is driven mechanically by the crankshaft (210) through a cam mechanism, and wherein the cam mecham^'sm includes a cam mounted on the crankshaft (210).

8. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or

3, wherein the accumulator (120) comprises a pressure sensor (325) and a pressure regulator valve (330).

9. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or 3, and wherein the fuel pump (115) includes a metering valve and the accumulator (120) includes a pressure sensor (325).

10. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or 3, wherein the accumulator (120) is integrated with the fuel pump (115).

11. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or 3, wherein the injector (125) is mounted on a cylinder head (305) through a clamping arrangement (340), such that a longitudinal axis of the injector (125) is aligned to a central axis of the cylinder head (305).

12. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or 3, wherein the fuel pump (115) and the accumulator (120) are disposed on a same side of the two-stroke compression ignition engine (200).

13. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or

3, wherein the accumulator (120) is mounted on a cylinder head (305).

14. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or 3, wherein the accumulator (120) is mounted on a cylinder block.

15. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or 3, wherein the injector (125) comprises a plurality of orifices, arranged radially, to inject fuel in a combustion chamber (130) such that the injected fuel has a substantially disc shaped spray-pattern.

16. The two-stroke compression ignition engine (200) as claimed in any of the claims 1 or 3, wherein the fuel tank (110) includes a level sensor.

17. A small bore two-stroke compression ignition engine (200) comprising:

at least one cylinder (205);

a piston (215) movably disposed inside the cylinder (205); and

a crankshaft (210) operably connected to the piston (215);

characterized in that,

a fuel filter (112) connected to a fuel tank (110) to filter fuel received from the fuel tank (110) ;

a fuel pump (115) to pressurize the filtered fuel received from the fuel filter (112);