Claims:We Claim

1. A fuel filter (10) for a fuel injection system, said fuel filter (10) comprising:
a filter housing (12) adapted to store fuel;
a filter media (14) positioned within said filter housing (12), said filter media (14) adapted to filter fuel that is stored within said filter housing (12); characterized in that
a plurality of capillary tubes (16) positioned within said filter media (14), each of said plurality of capillary tubes (16) extending from a top portion of said filter housing (12) to a bottom portion of said filter housing (12), and wherein each of said plurality of capillary tubes (16) is adapted to store fuel that is filtered through said filter media (14) at a displacement that is greater than the displacement of fuel that is stored within said filter housing (12), the displacement of fuel that is stored within each of said plurality of capillary tubes (16) being greater than the displacement of fuel that is stored within said filter housing (12) because of surface tension that is prevalent within each of said plurality of capillary tubes (16).
, 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] This invention relates to a fuel filter, and more specifically to a fuel filter for a fuel injection system.

Background of the invention
[0002] US 2004222142 A describes a fuel filter. The fuel filter includes a filtration chamber consisting of an inner cylinder and an outer cylinder disposed concentrically with a predetermined space, a bottom part that closes an opening end on one end side of the inner cylinder and the outer cylinder, and a lid part disposed with a fuel suction pipe and a fuel sending pipe, that closes an opening end on the other end side of the inner cylinder and the outer cylinder. A filtering member is accommodated in a filtration chamber and filtrates fuel that flows into the filtration chamber. In this filter, a centrifugal force applying member for centrifuging the fuel that flows into it is disposed at the end of the filtering member on the lid part side. A groove portion extending along an inner wall face of the outer cylinder is formed on the bottom part.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a schematic diagram of a fuel filter of the fuel injection system.

Detailed description of the embodiments
[0004] Figure 1 illustrates a fuel filter 10 for a fuel injection system. The fuel filter 10 comprises a filter housing 12 adapted to store fuel. A filter media 14 is positioned within the filter housing 12, the filter media 14 adapted to filter fuel that is stored within the filter housing 12. A plurality of capillary tubes 16 is positioned within the filter media 14, each of the plurality of capillary tubes 16 extending from a top portion of the filter housing 12 to a bottom portion of the filter housing 12, and wherein each of the plurality of capillary tubes 16 is adapted to store fuel that is filtered through the filter media 14 at a displacement that is greater than the displacement of fuel that is stored within the filter housing 12, the displacement of fuel that is stored within each of the plurality of capillary tubes 16 being greater than the displacement of fuel that is stored within the filter housing 12 because of surface tension that is prevalent within each of the plurality of capillary tubes 16.

[0005] The fuel filter 10 for the fuel injection system comprises a filter housing 12 that is adapted to store fuel. More specifically, fuel that is channeled within the filter housing 12 via a fuel inlet supply path is stored within the filter housing 12 for further purification. A filter media 14 is positioned within the filter housing 12. The filter media 14 is adapted to filter the fuel that flows into and is stored within the filter housing 12. As the fuel is continuously depleted from the fuel filter 10 from an outlet of the fuel filter 10, the fuel that is present within the filter housing 12 continuously flows through the filter media 14 and is delivered out of the filter housing 12 to a high pressure fuel pump.

[0006] A plurality of capillary tubes 16 is positioned within the filter media 14. More specifically, a tubular member 18 is positioned within the filter media 14. The tubular member 18 comprises an outer surface 20 comprising an outer diameter, an inner surface 22 comprising an inner diameter, and a solid portion extending between the inner surface 22 and the outer surface 20 of the tubular member 24. The inner surface 22 of the tubular member 18 circumscribes a bore that is defined therethrough and extends from a first end of the tubular member 18 to an opposite second end of the tubular member 18. The plurality of capillary tubes 16 are positioned within the inner surface of the tubular member 18, wherein each of the plurality of capillary tubes 16 extends from the first end of the tubular member 18 to the opposite second end of the tubular member 18. Each of the plurality of capillary tubes 16 is adapted to store fuel that is filtered through the filter media 14. More specifically, as fuel is filtered through the filter media 14 from the filter housing 12, the filtered fuel flows through the first end which is at the bottom portion of the tubular member 24.

[0007] Therein, the fuel is channeled through each of the plurality of capillary tubes 16 from the first end of the tubular member 18 to the opposite second end of the tubular member 18. Therefore, the fuel that is channeled through the filter media 14 is channeled through each of the plurality of capillary tubes 16 via the first end of the tubular member 18. As the fuel flows through each of the plurality of capillary tubes 16 via the first end of the tubular member 18, the fuel flows through each of the capillary tubes 16 and rises up along the longitudinal axis of each of the capillary tubes 16. The displacement of the fuel that is stored within each of the plurality of capillary tubes 16 is greater than the displacement of the fuel that is stored within the filter housing 12. The displacement of the fuel that is stored within each of the plurality of capillary tubes 16 is greater than the displacement of the fuel that is stored within the filter housing 12 because of the surface tension that is prevalent within the inner surface of each of the plurality of capillary tubes 16. The surface tension that is prevalent on the inner surface of each of the capillary tubes 16 causes the fuel to rise up to a displacement that is slightly greater than the displacement of fuel that is present within the filter housing 12. Therefore, since the displacement of fuel within the inner surface of each of the plurality of capillary tubes is greater than the displacement of fuel within the filter housing 12, a shorter length of each of the capillary tubes 16 is required to be traversed by the fuel to reach the opposite second end of the tubular member 18 from where it is delivered to a high pressure fuel pump. The shorter displacement of each of the capillary tubes 16 that is required to be traversed by the fuel to reach the opposite second end of the tubular member 18 causes the fuel to be delivered much faster to the high pressure fuel pump. Hence, the efficiency of the fuel injection system is enhanced as a consequence of the shorter displacement of each of the plurality of capillary tubes 16 that is required to be traversed by the fuel before it is delivered to the high pressure fuel pump.

[0008] A working of the fuel filter 10 for the fuel injection system is described as an example. Fresh fuel is channeled within the filter housing 12 from a fuel tank of the vehicle. From the filter housing 12, the fuel is channeled through the filter media 14. As the fuel flows through the filter media 14, the fuel is channeled through each of the plurality of capillary tubes 16 via the first end of the tubular member 18. As the fuel flows through each of the plurality of capillary tubes 16 via the first end of the tubular member 18, the fuel that flows through each of the capillary tubes 16 rises up along the length of each of the capillary tubes 16. Owing to the surface tension that acts along the inner surface of each of the capillary tubes 16, the displacement of the fuel that is stored in each of the capillary tubes 16 is greater than the displacement of the fuel that is stored within the filter housing 12. The surface tension that is prevalent on the surface of each of the capillary tubes 16 causes the fuel to rise up to a displacement that is slightly greater than the displacement of the fuel that is stored within the filter housing 12. Therefore, since the displacement of the fuel that is stored within each of the capillary tubes 16 is greater than the displacement of fuel that is stored within the filter housing 12, a shorter length of each of the capillary tubes 16 is required to be traversed by the fuel to reach the second end of the tubular member 24 from where it is delivered to the high pressure fuel pump. The shorter length of each of the capillary tubes 16 that is required to be traversed by the fuel to reach the second end of the tubular member 24 causes the fuel to be delivered much faster to the high pressure fuel pump. Hence, the efficiency of the fuel injection system is enhanced as a consequence of the shorter displacement of the capillary tubes 16 to be traversed by the fuel before it is delivered to the high pressure fuel pump.

[0010] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.