Claims:We Claim:

1. A fuel supply system (100) for an internal combustion engine, comprising: a fuel supply pump (101) adapted to draw fuel from a fuel tank (102) and convey it continuously to a high-pressure pump through a cam arrangement (104), said cam arrangement (104) is adapted to convert rotary motion of a camshaft to the reciprocating motion of the fuel pump piston;
characterized in that;
a magnetic filter (110) disposed in the fuel passage from said fuel tank (102) to the cam arrangement (104) before fuel reaches the cam arrangement (104) and adapted to remove magnetic particles contained in the fuel discharged from the fuel tank (102).

2. The fuel supply system (100) as claimed in claim 1, wherein said magnetic filter (110) is located in passage from said fuel tank (102) to the inlet of a cam arrangement (104).
, Description:Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] Present invention relates to a filtration technique in fuel injection pump to overcome the drive train failures in a fuel supply pump of common rail systems.

Background of the invention
[0002] Commercial vehicles are subjected to a variety of vehicle applications and are required to operate in a wide range of environmental and load conditions. For example, some commercial vehicles, such as tractor-trailers, are required to travel long distances over highways with few stops and are subjected to high heat in desert areas and steep grades in mountainous areas. Other commercial vehicles, such as delivery trucks, operate within a city and/or associated suburban area and perform multiple starts and stops each day. These commercial vehicles each have a drivetrain that must be able to operate in a variety of applications under high loads and over a wide range of environmental conditions.

[0003] Commercial vehicle drivetrains include components such as an engine, transmission, transfer case, driveline, drive axle, differential assembly, and inter-axle differential assembly, for example. During vehicle operation, any one of these components could experience conditions that could lead toward early failure due to shock loads, fatigue, overload, and/or overheating. The problem to be solved/eliminated is the drive train failure in CP4 pumps. There are many drive train failure reported in the US, India, Korea market and law suits are going on. On root cause analysis, the particles are also one of the contributing factors.

[0004] The prior art US6526947B2 discloses a high-pressure fuel pump accelerates a rise in fuel pressure from engine start-up to shorten an engine start-up time, reduce an exhaust gas substance and improve or increase an engine output. The high-pressure fuel pump is part of a control device which controls an in-cylinder injection engine having a fuel injection valve, a high-pressure fuel pump, and a crank angle sensor. The high-pressure fuel pump is provided with a plunger for pressurizing the fuel placed in the high-pressure fuel pump, a pump drive cam, and a cam angle sensor. A drive signal setting device outputs drive signals to the high-pressure fuel pump at least two or more times from the time of crank angle sensor signal detection to the determination time of the crank and cam angle sensor phases.

Brief description of the accompanying drawing
[0005] Different modes of the invention is disclosed in detail in the description and illustrated in the accompanying drawings:

[0006] Figure 1 illustrates modified design of a fuel supply system for an engine, in accordance with embodiments of the invention.

Detailed description of the embodiments
[0007] Fig. 1 illustrates a fuel supply system 100 for an internal combustion engine with a modified design, in accordance with one embodiment of the invention. The fuel supply system 100 comprises a fuel supply pump 101, a fuel tank 102, a cam arrangement 104, and a magnetic filter 110. Each component is described in further details below.

[0008] The fuel tank 102 connected to the fuel supply pump 101, adapted to accumulate the fuel. The fuel supply pump 101 adapted to draw fuel from a fuel tank 102 and convey it continuously to a high-pressure pump through the cam arrangement 104. The fuel supply pump 101 receives a quantity of the fuel from fuel tank 102, through inlet port of the fuel supply pump 102.

[0009] The cam arrangement 104 has a drive train comprising a camshaft and a roller. In an internal combustion engine, the camshaft is longitudinal rotating shaft having attached disks of irregular shape known as cams, which actuate the intake and exhaust valves of the engine cylinders. A plug-in pump is a type of fuel pump where the roller tappet or the actuating part of the fuel pump plug into a receiving bore in a cylinder block of an internal combustion engine. The fuel pump part that has a pump piston in the pump housing is structurally separate from the actuating part with the roller tappet that is driven by the cam.

[0010] Further the cam arrangement 104 functions on the camshaft and roller’s rotating mechanism which helps in converting the rotary motion of the camshaft to the reciprocating motion of a piston. In general, during the working of a fuel pump, the cam of the fuel pump is in engagement with the piston of said fuel pump. When the camshaft rotates, the cam rotates and it causes the piston to reciprocate, which in turn pressurizes the fuel and the pressurized fuel is then delivered to the either higher pressure circuit and the components in the high pressure circuit. The camshaft of the fuel pump 101 is driven by the drive shaft of the engine. A person skilled in the art would already be aware of the different type of mechanisms used for transmission of the rotation of the engine drive shaft to the cam shaft of the fuel injection pump.

[0011] Furthermore, the a magnetic filter 110 is disposed in the fuel passage from the fuel tank 102 to the cam arrangement 104 before fuel reaches the cam arrangement 104 the magnetic filter 110 is adapted to remove magnetic particles contained in the fuel discharged from the fuel tank 102. In one embodiment, the magnetic filter 110 is located in passage from the fuel tank 102 to the inlet of a cam arrangement 104.

[0012] The fuel supply system 100 proposed in the present invention, integrates the magnetic filter 110 along with magnetic properties into the fuel supply pump 101 before the fuel reaches the cam room 104 where the drive train (i.e. cam and roller) is present. In a conventional fuel supply system there are three filters inside a fuel supply pump namely at overflow valve, suction valve and third filter at metering unit. All these filters are present in the circuit after the cam room. However, the present invention proposed this magnetic filter 110 before the fuel enters the cam room 104 from the pump 101 out.

[0013] If this filter is not there, then the particle will create the pre-damage of the drive train which in the later run will fail. All kinds of magnetic particles like burrs, etc. which are even less than filter size will also be attracted by magnetic force.

[0014] The present invention intends to eliminate drive train failure in an engine and all the issues related to particle contamination in fuel supplied from the fuel supply system.

[0015] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.