Field of the invention
[0001]This invention relates to a fuel filter with an auxiliary flap.
Background of the invention
[0002]In the existing fuel filters, there are two flaps, which are strategically operated during a priming condition and normal working conditions. The pressure drop in the above fuel filter is directly contributed to fuel filter mileage or service interval change over. Lesser the fuel filter pressure drop higher the filter mileage or service interval change over benefit. With the two-flap arrangement in the fuel filter, the flow of the fuel into the fuel filter takes a longer duration, which reduces the efficiency of the vehicle during cranking.
[0003] A Prior art document DE102018110660 discloses a particle discharge device for a filter arrangement , comprising a housing , a first valve device and a second valve device spaced from the first valve device in a longitudinal direction (L) of the housing.One of the two valve devices has an actively actuated valve flap and the other of the two valve devices has a passively actuated valve flap.
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.
Detailed description of the embodiments
[0006] 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 having a filter head 13. The fuel filter 12 comprises an inlet 16 and an outlet 18 that are made on the filter head 13. The fuel filter 12 further comprises a filter element 20 detachably fitted inside the housing 14. The fuel filter 12 comprises a first flap 22 and a second flap 24

formed in the filter head 13, the first and the second flaps (22,24) are adapted to allow fuel into the housing 14 from the inlet 16. The fuel filter 12 further comprises an auxiliary flap 26 made in proximity to the inlet 16 on the filter head 13. The auxiliary flap 26 adapted to allow fuel directly into the housing 14 from the inlet 16 during a normal running condition.
[0007] 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 having the impurities is filtered in the fuel filter 12 and the filtered fuel from the outlet 18 of the fuel filter 12 flows into the high-pressure pump 44.
[0008] The filter element 20 is positioned in a cylindrical shape in the housing 14. The fuel from the inlet 14 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 18. 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 acts as the filter head 13 to hold the filter element 20 when assembled into the housing 14. According to one embodiment of the invention, the filter head 13 and the housing 14 are detachably connected to each other.
[0009]According to one embodiment of the invention, the fuel filter 12 is a spin-on type fuel filter. The conventional fuel filters uses two flaps (22, 24) one located in proximity to the inlet 16 and other located in proximity to the outlet 18. For better understanding of the invention, one flap is referred as the first flap 22 and other flap is referred as the second flap 24.

[0010]The fuel from the inlet 14 flows through the first flap 22, passes through a passage (not shown) present in the filter head 13 towards the second flap 24, and enters the housing 14. The fuel that entered the housing 14 is filtered and flows out of the fuel filter 12 via the outlet 18. The first and the second flaps (22, 24) comprises a flexible element 32 and a stopper 34 connected to the flexible element 32 for the fuel to flow into the housing 14.
[0011] The auxiliary flap 26 is positioned in proximity to the inlet 14 and to the first flap 22 as shown in the figure 1. The auxiliary flap 22 is positioned in line with the second flap 24, but near to the inlet 16 of the fuel filter 12. The auxiliary flap 26 comprises a first portion 28 and a second portion 29. The first portion 28 and the second portion 29 are secured at one end by a component 30. According to one embodiment of the invention, the first portion 28 and the second portion, 29 of the auxiliary flap 26 are identical to each other.
[0012] Each of the first and the second portions (28,29) of the auxiliary flap 26 comprises a flexible element 32 and a stopper 34 attached to the flexible element 32, wherein the flexible element 32 is made of a sheet metal and the stopper 34 is made of a zinc casting material. However, the materials of the flexible element 32 and the stopper 34 are not restricted to the above mentioned materials, but can be any of the others materials like plastic, rubber and the like that is known in the state of the art.
[0013] The first portion 28 and the second portion 29 of the auxiliary flap 26 is connected to each other in any one of the following forms comprising a v-shaped form, formed in a straight line and a butterfly wings form. It is to be understood that, the shape of the auxiliary flap 26 is not restricted to the above-disclosed forms, but can be any other shape/form that is known to a person skilled in the art. The component of the auxiliary flap 26 is chosen from a group of components comprising a screw, a bolt, a fastener, a rivet, a snap and the like.

[0014] According to one embodiment of the invention the first flap 22, the second flap 24 and the auxiliary flap 26 are mechanically controlled. The pressure of the flow of the fuel opens/closes the above-mentioned flaps (22, 24 and 26).
[0015] During a priming condition of the vehicle (i.e., during the filling of the fuel), a primer 35 is operated manually in the radial direction.ie. by operating the primer in the upward and downward directions. When the primer 35 is pulled up (upward direction), the fuel from the inlet 14 flows into the first flap 22 and flows towards the second flap 24. During this scenario, the first flap 22 is opened and the second flap 24 and the auxiliary flap 26 are in closed condition. When the primer 35 is pushed down (down ward direction), the fuel that is entered through the first flap 22, flows into the housing 14 through the second flap 24.
[0016]During this scenario, the second flap 24 is opened and the first flap 22 and the auxiliary flap 26 are in closed condition. During the priming condition, the first flap 222and the second flap 24 are operated simultaneously and the auxiliary flap 26 is maintained closed, as the flow of the fuel will be less than a predefined value. In other words, the force of the fuel flowing into the fuel filter 12 during the priming condition will not be sufficient for the auxiliary flap 26 to move from the closed positon to the open position.
[0017] During the normal working condition of the vehicle, the fuel flowing through the inlet 16 enters directly into the housing 14 via the auxiliary flap 26. The force with which the fuel is flowing through the inlet 16 will be equal to more than the predefined value, thus the auxiliary flap 26 is opened to allow the fuel in the housing 14. During this scenario, the first and the second flaps (22, 24) are in closed condition. The fuel from the inlet 16 flows into the housing 14 through the flexible element 34 of the corresponding first portion 28 and the second portion 29 of the auxiliary flap 26, at the same time, thus increasing the amount of fuel flowing into the housing 14 per one fuel flow cycle.

[0018] With the above disclosed auxiliary flap 26, the fuel filling time is decreased, since the fuel enters the housing directly instead of taking a long path in the filter head 13 (inlet 16- first flap 22-second flap 24- housing 14). With the auxiliary flap 26, the amount of fuel entering into the housing 14 is increased by two times, as there are two identical portions (28, 29) are connected to each other to form an auxiliary flap 26. For instance, in the conventional arrangement, only 12% of fuel is allowed through the first and the second flaps (22, 24) to avoid the damage of the flaps (22, 24) and to prevent the back leak of the fuel into the fuel tank. However, with the present auxiliary flap 26, a double value, ie. 24% (two 12%) is allowed, as the auxiliary flap 26 as two paths in the form of two flexible elements 34 (one in first portion 28 and other in second portion 29) for the flow of the fuel into the housing 14. The above arrangement improves the startablity of the vehicle as more amount of fuel is filled in the housing 14 in less duration.
[0019] 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.

We Claim:
1. A fuel filter (12) in a fuel supply system (10), said fuel filter (12) comprising:
- a housing (14) having a filter head (13);
- an inlet (16) and an outlet (18) made on said filter head (13);
- a filter element (20) detachably fitted inside said housing (14);
- a first flap (22) and a second flap (24) formed in said filter head (13) adapted to allow fuel into said housing from said inlet (16);
characterized in that:
an auxiliary flap (26) made in proximity to said inlet (16) on said filter head (13), said auxiliary flap (26) adapted to allow fuel directly into said housing (14) from said inlet (16) during a normal running condition.
2. The fuel filter (12) as claimed in claim 1, wherein said auxiliary flap (26) comprises a first portion (28) and a second portion (29), said first portion (28) and said second portion (29) are secured at one end by a component (30).
3. The fuel filter (12) as claimed in claim 2, wherein said component (30) is chosen from a group of components comprising a screw, a bolt, a fastener, a rivet, a snap .
4. The fuel filter (12) as claimed in claim 2, wherein said first portion (28) and said second portion (29) of said auxiliary flap (26) are made identical.
5. The fuel filter (12) as claimed in claim 2, wherein said first portion (28) and said second portion (29) of said auxiliary flap (26) are positioned in any one of the forms comprising a V-shape, a straight line and a butterfly wings shape.
6. The fuel filter (12) as claimed in claim 2, wherein each of said first portion (28) and said second portion (29) comprises a flexible element (32) and a stopper (34) attached to said flexible element (32).

7. The fuel filter (12) as claimed in claim 6, wherein said flexible element (32) is made of a sheet metal and said stopper (34) is made of a zinc casting material.
8. The fuel filter (12) as claimed in claim 1, wherein said auxiliary flap (26) and said first and second flaps (22,24) are mechanically controlled.
9. The fuel filter (12) as claimed in claim 1, wherein said auxiliary flap (26) is opened and said first and second flaps (22,24) are closed during said normal running condition of said fuel supply system (10).
10. The fuel filter (12) as claimed in claim 1, wherein said auxiliary flap (26) is closed and said first and second flaps (22,24) are opened during a priming condition of said fuel supply system (10).