Claims:1. A filter (100) for a fuel injector, said filter 100 located along an inlet of said fuel injector and comprising:
a body (102) comprising at least one flute (104), said flute (104) comprising a first end (103) proximal to an inlet of said injector to receive fuel; characterized in that

a sac (106) located at a second end 105 of said flute (104) and adapted to trap particulates present in fuel.

2. The filter (100) of claim 1, wherein a circumferential slot (108) is provided between said second end (105) and an outlet of said filter (100).

3. The filter (100) of claim 1 and 2, wherein said outlet of said filter 100 further comprises plurality of flow paths (110), said flow path in flow communication with a nozzle of said fuel injector.

4. The filter (100) of claim 3, wherein a longitudinal slot (112) is provided between said first end of said flute (104) and said sac (106).

5. The filter (100) of claim 1, wherein a flow path (107) is provided between said sac (106) and said flute (104).
, Description:Field of the invention
[0001] This invention relates to the field of a filter in a fuel injector.

Background of the invention.
[0002] Particles in fuel are the main causes for the failure of injector components. Particle entrapment capability is currently limited and any entrapped particle can disintegrate into smaller pieces over time and enters the injector and pass through the injector and substantially decreases the robustness of the injector and nozzle over life time. A filter is used in a fuel injector to prevent particles/impurities from being injected into the engine cylinder along with fuel. The filter used in the injector is generally called as the "Edge filter" or "Stab filter". The filter is used in the high pressure connector (HPC) of common rail injector to help prevent entry of particles >=22micro meter which could adversely affect injector functionality. The filter comprises a flute through which fuel enters and then flows towards the edge of the flute. The edges of overlapping V-shaped flow flutes help break these particles into smaller pieces. These smaller pieces of particles enter inside the injector and nozzle and affects the functionality of the injector. Hence there is a need to prevent particles from entering the nozzle of the fuel injector.

Brief description of the accompanying drawing
[0003] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:
[0004] FIG. 1 illustrates filter for a fuel injector; and
[0005] FIG. 2 illustrates an embodiment of the filter for the fuel injector.

Detailed description of the embodiments
[0006] FIG. 1 illustrates filter 100 for a fuel injector. The filter 100 is located along an inlet of said fuel injector and comprises a body 102 comprising at least one flute 104, the flute 104 comprises a first end proximal to an inlet of the filter 100 to receive fuel. A sac 106 is located at a second end 105 of the flute 104 and adapted to trap particulates present in the fuel. A circumferential slot 108is provided between the second end 105 and an outlet of the filter 100. A longitudinal slot 112 is provided between said first end of the flute 104 and the sac 106. The second end 105 further comprises plurality of flow paths 110.
[0007] The construction of the filter 100 will be explained in further detail. The filter 100 is adapted to be located along the inlet of the fuel injector. The filter 100 comprises a body 102, the profile of the body 102 is such that it can be inserted into the inlet of the injector. The body 102 comprises at least one flute 104, the flute 104 comprises a first end proximal to the filter 100. The second end 105 of the flute 104 comprises a sac 106. A flow path (107) is provided between the sac (106) and the flute (104). The flow path 107 enables the particles to flow into the sac 106.The sac 106 is in the form hollow cavity, the profile of the sac 106 is such that the particles entering the sac 106 are trapped within the sac 106 itself. A circumferential slot 108is provided between the second end 105 and an outlet of the filter 100. The second end 105 further comprises plurality of flow paths 110.
[0008] The working of filter 100 located in the fuel injector will be explain with reference to FIG. 1. The fuel is received into the injector via a pipe. The pipe is adapted to receive fuel from a high pressure fuel injection pump. The fuel enters the inlet of the fuel injector, and flows into the filter 100 that is located along the inlet. The filter 100 comprises a body 102 comprising at least one flute 104. The fuel flows through this flute 104, while flowing through the flute 104, heavier particles sink and accumulated in the longitudinal slot 112is provided between the first end of said flute 104 and the sac 106. The finer particles flow along with the fuel and impinge onto the sac 106 located at a second end 105 of the flute 104. The fuel than flows through a circumferential slot, the function of the circumferential slot 108 is to trap particles that cannot be trapped by the sac 106 and the longitudinal slot. The fuel flowing out of the circumferential slot 108 is thus free of any particles and flows out of the filter 100 through plurality of flow paths 110, the flow path in flow communication with a nozzle of said fuel injector.
[0009] FIG. 2 illustrates an embodiment of the filter for the fuel injector. The filter 100 is located along the inlet of the fuel injector. The filter comprises a sac (106) for entrapment of particulates present in the fuel. A flow path (107) is provided between said sac (106) and the flute (104). The sac is provided only to trap the particulates that are present in the fuel. The flow path 107 functions like a channel to enable the particulates to move into the sac. These particulates strike the flute 104 with high velocity and momentum and over a period of time these particulates disintegrate into smaller pieces and pass through the injector. In order to prevent the particulates from entering the injector the sac 106 is provided. The length of the filter 100 at the injector side may be increased up to the sac 106 (also called as particulate collecting region), this helps in reducing the clearance between the filter 100 and the injector casing inlet which avoids particulates escaping from the sac 106.
[0010] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention in terms of type of filter/injector. 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.
[0011] Adapted’ or ‘arranged’, in the context of the instant disclosure, refers to the technical capability or the technical capacity of a component, in relation to which the term ‘adapted’ or ‘arranged’ is used, to carry out or execute a specified action or actions, upon the requirement of the specified action or actions to be carried out or executed. Moreover, the usage of the term ‘adapted’ or ‘arranged’ here, is in reference with the normal technical capability or technical capacity of the component, imparted by the design or the structure or the composition of the component, and not in reference with any special or extraneous capability or capacity, beyond the scope of the normal technical capability or technical capacity