Claims:We Claim:
1. A fuel filter (12) in a fuel supply system (10), said fuel filter (12) comprising:
- a housing (14);
- a top end cap (16);
- a bottom end cap (18);
- a filter element (20) detachably fitted inside said housing (14), in between said top end cap (16) and said bottom end cap (18);
characterized in that:
said bottom end cap (18) comprises:
- a first portion (22) to accommodate said filter element (20), and
- a second portion (24) connected around said first portion (22) through at least one flexible element (26).

2. The fuel filter (12) as claimed in claim 1, wherein dimensions of said housing (14) are made corresponding to dimensions of said second portion (24).

3. The fuel filter (12) as claimed in claim 1, wherein said at least one flexible element (26) is chosen from any one of the following flexible elements (26) comprising multiple ribs and multiple supporting legs.

4. The fuel filter (12) as claimed in claim 3, wherein said second portion (24) comprises multiple ribs (28) made in between said first portion (22) and said second portion (24), said multiple ribs (28) adapted to hold said filter element (20) in said housing (14).

5. The fuel filter (12) as claimed in claim 3, wherein said second portion (24) comprises multiple supporting legs (30) adapted to adjust a position of said filter element (20) in said housing (14) during assembly.

6. The fuel filter (12) as claimed in claim 1, wherein said housing (14) comprises multiple cut-sections (32) corresponding to multiple said flexible elements (26) of said bottom end cap (18) of said filter element (20).

7. The fuel filter (12) as claimed in claim 1, wherein said at least one flexible element (26) is made as an integral component in said bottom end cap (18).

8. The fuel filter (12) as claimed in claim 1, wherein said bottom end cap (18) is made of a material chosen form a group of materials comprising plastic, rubber.

9. The fuel filter (12) as claimed in claim 1, wherein said bottom end cap (18) is positioned in proximity to a drain plug (34) of said fuel filter (12).
, 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 in a fuel supply system.

Background of the invention
[0002]In the existing fuel filters, a conical spring is used for element height adjustment tolerance during assembly and also as element vibration dampening. However, during vehicle running conditions, because of the vibration spring cannot hold the filter element tightly in place, the impure fuel is flows into the clean side of the fuel filter. In few of the existing type of fuel filters, the filtering element is held at the top cap and the remaining portion (the spin-on top and bottom portion) of the filtering element is held free. This type of mounting design is called as a cantilever type, has less endurance for the vibrations during the running conditions, because of the tuning fork effect. Due to this effect, the impure fuel migrates onto the cleaner side of the fuel filter.

[0003] A Prior art document US20070095733 discloses a fuel pump having double filter elements that contact the fuel pump module reservoir wall will dampen vibrational energy that originates in the fuel pump and propagates through the filter elements and into the fuel pump module reservoir. The fuel filter apparatus situated within the fuel pump module reservoir has a fuel pump with a fuel filter carrier attached to an end of the fuel pump. The fuel filters that attach to the fuel filter carrier are doubled such that one lies over the other in an over-lapping or sock-like arrangement.

Brief description of the accompanying drawing
[0004] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:
[0005] Fig. 1 illustrates a fuel filter in a fuel supply system, in accordance with an embodiment of the invention
[0006] Fig. 2 illustrates the fuel filter in the fuel supply system, in accordance with an embodiment of the invention; and
[0007] Fig. 3 illustrates the fuel filter in the fuel supply system, in accordance with an embodiment of the invention.

Detailed description of the embodiments
[0008] Fig.1 illustrates a fuel filter in a fuel supply system, in accordance with one embodiment of the invention. The fuel filter 12 comprises a housing 14 and a top end cap 16. The fuel filter 12 further comprises a bottom end cap 18 and a filter element 20 detachably fitted inside the housing 14, in between the top end cap 16 and the bottom end cap 18. The bottom end cap 18 comprises a first portion 22 to accommodate the filter element 20 and a second portion 24 connected around the first portion 22 through at least one flexible element 26.

[0009] Further the construction of the fuel supply system and the components of the systems is explained as follows. The fuel supply system 10 comprises a fuel tank 40 and a fuel pump 42 adapted to pump the fuel from the fuel tank 40. The system 10 comprises a high-pressure fuel pump 44 connected to the fuel filter 12. The fuel from the fuel tank 40 is pumped into the high-pressure fuel pump 44 via the fuel filter 12. From the high-pressure pump 44, the pressurized fuel is made to flow into a common rail system (not shown). The fuel filter 12 comprises an inlet 46 and an outlet 48 (as shown in Fig. 2) for allowing the flow of the fuel into the high-pressure pump 44 from the fuel tank 40. The fuel having the impurities is filtered in the fuel filter 12 and the filtered fuel from the outlet 48 of the fuel filter flows into the high-pressure pump 44.

[0010] The filter element 20 is positioned in a cylindrical shape in the housing 14. The fuel from the inlet 46 flows into an area between an inner surface of the housing 14 and an outer surface of the filter element 20. The filtered fuel flows out from the fuel filter 12 via the outlet 48. However, the shape of the filter element 20 is not restricted to the cylindrical shape, but can be any other shape that is known in the person skilled in the art. The housing 14 comprises a top portion 36 and a bottom portion 38 wherein the top portion 36 accommodates the top end cap 16 to hold the filter element 20 when assembled into the housing 14. According to one embodiment of the invention, the top end cap 16 is made as an integral component of the top portion 36 of the housing 14.

[0011]The bottom end cap 18 is positioned at the bottom portion 38 of the housing 14. The bottom portion 38 of the housing 14 comprises a drain plug 34 to drain an excessive amount of the fuel present in the fuel filter 12 once the filtration process is completed. The bottom end cap 18 is positioned in proximity to the drain plug 34 in the bottom portion 38 of the housing 14.

[0012]The dimensions of the bottom portion 38 of the housing 14 is made corresponding to the dimensions of the second portion 24 of the bottom end cap 18. The bottom portion 38 of the housing 14 comprises multiple cut-sections 32 corresponding to the multiple flexible elements 26 of the bottom end cap 18 of the filter element 20. At least one flexible element 26 connects the first portion 22 and the second portion 24 of the bottom end cap 18, and is chosen from any one of the following flexible elements 26 comprising multiple ribs 28 and multiple supporting legs 30. However, the flexible elements 26 are not restricted to the above-disclosed elements but can be any of the flexible elements 26 that are known in the state of the art.

[0013] According to one embodiment of the invention, the at least one flexible element 26 (multiple supporting legs/multiple ribs 28) are made as an integral part of the bottom end cap 18. The bottom end cap 18 is made of a material chosen from a group of materials comprising plastic, rubber and the like. More precisely, the bottom end cap 18 is made of a flexible material that can withstand the vibrations that occurs during the operation of the vehicle.

[0014] Fig.2 illustrates a fuel filter in a fuel supply system, in accordance with an embodiment of the invention. The at least one flexible elements 26 are multiple ribs 28. The multiple ribs 28 connects the first portion 22 and the second portion 24, wherein the multiple ribs 28 adapted to hold the filter element 20 in the housing 14. The filter element 20 is positioned on the bottom end cap 18 such that, a portion of the filter element 20 is fitted over the first portion 22 and the second portion 24 of the bottom end cap 18.

[0015]The multiple ribs 28 present in between the first portion 22 and the second portion 28 of the bottom end cap 18 holds the filter element 20 rigidly during the vibrations that occur during the operating condition of the vehicle. As mentioned above, the bottom portion 38 of the housing 14 comprises multiple cut-sections 32 corresponding to the shape of the multiple ribs 28, such that, the bottom end cap 18 is detachably fitted in the bottom portion 38 of the housing 14.

[0016] Fig. 3 illustrates a fuel filter in a fuel supply system, in accordance with one embodiment of the invention. According to an embodiment of the invention, the at least one flexible elements 26 are multiple supporting legs 30 adapted to adjust a position of the filter element 20 in the housing 14 during assembly. The multiple supporting legs 30 are made on the outer surface of the second portion 24 of the bottom end cap 18. According to one embodiment of the invention, the multiple supporting legs 30 are made as an integral component of the second portion 24 of the bottom end cap 18. As disclosed above, the bottom portion 38 of the housing 14 comprises multiple cut-sections 32 to receive corresponding multiple supporting legs 30 of the bottom end cap 18.

[0017] The dimensions of the multiple cut-sections 32 in the bottom portion 38 of the housing 14 are made corresponding to the dimensions of the multiple supporting legs 30. The filter element 20 is fitted to the bottom end cap 18 and the combination of the filter element 20 along with the bottom end cap 18 is fitted in the bottom portion 38 of the housing 12 during assembly. The height of the filter element 20 is adjusted with the help of the multiple supporting legs 30 in the housing to secure the filter element 20 in the housing 14. With this arrangement, the filtration of the fuel passing through the fuel filter 12 from the fuel tank 40 is improved.

[0018] The above disclosed fuel filter 12 design helps in reducing the vibrations during the operating conditions of the vehicle due to the flexible nature of the bottom end cap 18 fitted to the filter element 20. The rigid position of the filter element 20 in the housing 14 of the fuel filter 12 due to presence of the multiple ribs 28 avoids the flow of the impure fuel onto the clean side of the filter 12, from where the fuel is pumped to the high-pressure fuel pump 44. With the help of the multiple supporting legs 30, the height of the filter element 20 in the housing 14 is adjusted efficiently during the assembly of the components in the fuel filter 12.

[0019] The bottom end cap 18 is positioned on a stepped bowl surface (bottom portion 38 of the housing 14) in the fuel filter 12 and attached/fitted to the filter element 20, thus eliminating the usage of a spring used to reduce the vibrations of the filter element 20 as known in the conventional methods. The elimination of the spring element in the fuel filter 12 makes the invention a cost-effective solution. With the present design of the fuel filter 12, the pressure of holding the filter element 20 only by the top end cap 16 (as in the conventional methods) is reduced.

[0020] 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.