Claims:We claim:
1. A filter device 1000 for a fuel supply system of an internal combustion engine of a vehicle, comprising:
a housing 100 and a cap 200 fitted on the housing 100;
said cap 200 comprising an inlet 201 and an outlet 202;
a filter element located in said housing 100 to define a dirt side and a clean side;
at least one part of said outlet 202 extends from the cap 200 towards said clean side in said housing 100;
characterized in that
an air venting assembly comprising:
an opening 204 in said outlet 202;
a sealing element 205 provided in proximity to said opening 204 and connected to a weight 207;
said weight 207 adapted to be displaced based on level of fuel in said dirt side in a manner such that air is vented from said dirt side to said clean side.
2. The filter device 1000 as claimed in claim 1, wherein said weight 207 adapted to be displaced in a manner such that the weight 207 maintains said sealing element 205 in a first operative position.
3. The filter device 1000 as claimed in claim 1, wherein said weight 207 adapted to be displaced in a manner such that the weight 207 maintains said sealing element 205 in a second operative position.
4. The filter device 1000 as claimed in claim 1, wherein said air venting assembly is positioned atone part 203 of said outlet 202, said one part 203 extending from the cap 200 towards the clean side in the housing 100.
5. The filter device 1000 as claimed in claim 1, wherein said sealing element 205 and said weight 207 are connected through a hinge 206.
6. A filter device 1000 for a fuel supply system of an internal combustion engine of a vehicle, comprising:
a housing 100 and a cap 200 fitted on the housing 100;
said cap 200 comprising an inlet 201, an outlet 202; and
a filter element arranged in said housing 100 to define a dirt side and a clean side;
characterized in that
an air venting assembly comprising:
an opening 204 in the outlet 202;
a receiving element 208 attached to the opening 204;
a ball attached to a weight 207 using an element 209; and
said weight 207 adapted to be displaced based on level of fuel in said dirt side such that air is vented from said dirt side to said clean side.
7. The filter device 1000 as claimed in claim 6, wherein said weight 207 adapted to be displaced in a manner such that the weight 207 maintains said ball in a first operative position.
8. The filter device 1000 as claimed in claim 6, wherein said weight 207 adapted to be displaced in a manner such that the weight 207 maintains said ball in a second operative position.
9. The filter device 1000 as claimed in claim 6, wherein said receiving element 208 is in a tapered conical shape.
, Description:Field of the invention
[0001] This disclosure relates to a fuel filter.
Background of the invention:
[0002] Fuel injection systems are sensitive to contaminants that are present in fuel. Fuel filter are the primary source of removing contaminants that are present in fuel. Fuel filters offer amongst others two specific functions i.e. reduce particulate impurities to avoid particulate erosion and separation of water from the fuel to avoid corrosion damage. Reducing particulate impurities is one of the functions of the fuel filter. In this way, it protects the wear-prone components of the fuel-injection system. Besides wear protection, fuel filters must also have a sufficient particulate storage capacity; otherwise they could become blocked before the end of the change interval. If they do become blocked, they would reduce fuel delivery quantity as well as engine performance. It is therefore essential to fit a fuel filter depending on the requirements of the fuel-injection system.

[0003] US patent, 7938958, discloses a de-aeration system for a fuel system, the fuel system having a housing for containing a fuel filter element, a fuel inlet and a fuel outlet is disclosed. The de-aeration system includes a de-aeration valve having a valve inlet in a lower face of the valve for connection to the housing for purging the air trapped in the housing. The de-aeration valve also includes a valve outlet in an upper face of the valve and a ball. The ball is configured to lift between the lower face and the upper face in response to an air pressure differential acting on the ball. This opens the valve to purge air trapped in the housing. The ball is further configured to close the valve by sealing against the valve outlet in the upper face in response to a pressure differential across the ball created by unfiltered fuel entering the valve.

Brief description of the accompanying drawings:
[0004] An embodiment of the disclosure is described with reference to the following accompanying drawings;
[0005] Figure 1 illustrates a detailed view a filter device in accordance with a first embodiment of the present invention; and
[0006] Figure 2 illustrates a detailed view of the fuel filter in accordance with a second embodiment of the present invention.
Detailed description of the embodiments:
[0007] Figure 1 illustrates a detailed view of a filter device 1000 in accordance with a first embodiment of the present invention. The filter device 1000 for a fuel supply system of an internal combustion engine of a vehicle is disclosed. The filter device 1000 comprises a housing 100 and a cap 200 fitted on the housing 100; the cap 200 comprising an inlet 201 and an outlet 202; a filter element located in the housing 100 to define a dirt side and a clean side; at least one part of the outlet 202 extends from the cap 200 towards the clean side in the housing 100; characterized in that an air venting assembly comprising: an opening 204 in the outlet 202; a sealing element 205 provided in proximity to the opening 204 and connected to a weight 207; the weight 207 adapted to be displaced based on level of fuel in the dirt side in a manner such that air is vented from the dirt side to the clean side.

[0008] For better understanding of the filter device in accordance with this disclosure, the filter device functions and some components can be disclosed in the following manner. Reducing particulate impurities is one of the functions of the filter device. In this way, it protects the wear-prone components of the fuel-injection system. Requirements regarding filter fineness have increased in the last few years and depend on the generation common-rail systems and the vehicle type. Depending on the application such as operating conditions, fuel contamination, engine life, new systems require filtration efficiencies ranging from 65% to 98.6%. Longer servicing intervals in more recent vehicles require greater particulate storage capacities as well as intensive fine particulate filtration.

[0009] The filter device has a plurality of components which are located in the housing or filter body. The filter element which is located in the filter body may be composed of several synthetic layers and cellulose. The filter media employ a preliminary fine filtering effect and guarantee maximum particulate retention capacity by separating particles within each filtering layer. Thus when the fuel containing the particulate matter comes in contact with the filter element, the filter element retains the particulate matter and allows the fuel to flow through the filter element. Another function that is also performed by the fuel filter is water separation. Water is also separated by the filter element as the droplets of water are formed on the filter element due to different surface tension of water and fuel. The separated water collects at the bottom of the filter body. Water level sensor are used in the fuel filter to determine the amount of water and water is either drained manually or using an automatic water disposal system.

[00010] In the context of the fuel injection system which contains amongst other components the fuel tank and the fuel filter, the fuel filter is located in the low pressure circuit downstream of the fuel tank. However, when the fuel tank is filled with fuel and when hand priming is performed in the filter head to fill the low pressure circuit the fuel is available till the fuel pump inlet. When the vehicle is cranked the engine starts with ease, but when the engine is stopped due to degasification effect of the fuel air/gases are released. This air/ gases get accumulated at the top volume of the filter device. In some cases the accumulation of air may be as much as 1/4th the fuel filter volume. When the engine is now cranked with the accumulated air at the top of the filter device only air is available at the pump inlet and not fuel. Due to presence of air accumulated at the top of the filter device, the fuel pump is starved of the presence of fuel and leads to non startability of the vehicle. The filter device in accordance with this disclosure focuses on the task of removing the air that is accumulated at the top of the filter device.

[00011] In accordance with the first embodiment of the present invention, the air venting assembly is positioned at one part 203 of the outlet 202, the one part 203 extending from the cap 200 towards the clean side in the housing 100. The sealing element 205 and the weight 207 are connected through a hinge 206.

[00012] The working of the filter device 1000 in accordance with the first embodiment of the present invention can be explained in the following manner. The working principle of the filter device 1000 in accordance with this invention is to vent out air from the dirt side to the clean side. The weight 207 is adapted to be displaced in a manner such that the weight 207 maintains the sealing element 205 in a first operative position. The weight 207 is displaced such that the weight 207 rests on top of the filter element when the fuel level in the dirt side is below a threshold. The hinge 206 supports the weight 207 to rest on top of the filter element. This makes the weight 207 to maintain the sealing element 205 in the first operative position. The first operative position of the sealing element 205 is such that the sealing element 205 opens the opening 204 to vent out air from the dirt side to the clean side. The air from the clean side escapes through the outlet 202. The fuel in the dirt side is not allowed to pass through the opening 204 as the fuel level is below the threshold. The presence of fuel at the clean side also ensures that the pump is not starved of fuel and there will be no engine startability issue.

[00013] The weight 207 is adapted to be displaced in a manner such that the weight 207 maintains the sealing element 205 in a second operative position. The weight 207 is displaced such that the weight 207 floats on the fuel when the fuel level is equal or above a threshold in the dirt side. This makes the weight 207 to maintain the sealing element 205 in the second operative position. The second operative position of the sealing element 205 is such that the sealing element 205 closes the opening 204 in the at least one part 203 of the outlet 202 extending from the cap 200 towards the clean side in the housing 100. The air in the dirt side is not allowed to pass through the opening 204 as the sealing element 205 closes the opening 204 when the fuel level is equal or above the threshold. This also prevents the fuel in the dirt side pass through the opening 204. Thus, the fuel filter reduces the intermixing of the fuel from the dirt side with the fuel in the clean side.

[00014] Figure 2 illustrates a detailed view of the filter device 1000 in accordance with a second embodiment of the present invention. In accordance with the second embodiment of this disclosure, the filter device 1000 for the fuel supply system of the internal combustion engine of the vehicle comprises the housing 100 and the cap 200 fitted on the housing 100; the cap 200 comprises the inlet 201 and the outlet 202; and the filter element arranged in the housing 100 to define the dirt side and the clean side; characterized in that the air venting assembly comprising: the opening 204 in the outlet 202; a receiving element 208 attached to the opening 204; a ball attached to a weight 207 using an element 209; and the weight 207 adapted to be displaced based on level of fuel in the dirt side such that air is vented from the dirt side to the clean side.

[00015] The air venting assembly is positioned at a horizontal outlet passage of the outlet 202. The receiving element 208 is in a tapered conical shape. The receiving element 208 is perpendicularly attached to the opening 204.

[00016] The working of the filter device 1000 in accordance with the second embodiment of the present invention can be explained in the following manner. The working principle of the filter device 1000 in accordance with this second embodiment of the present invention is to vent out air from the dirt side to the clean side. The weight 207 is adapted to be displaced in a manner such that the weight 207 maintains the ball in a first operative position. The weight 207 is displaced such that the weight 207 moves downwards when the fuel level in the dirt side is lesser than a threshold. This makes the weight 207 to maintain the ball in the first operative position. The ball movable within the receiving element 208 opens the opening 204 when the ball is in the first operative position. The air escapes through the horizontal outlet passage of the outlet 202. The fuel in the dirt side is not allowed to pass through the opening 204 as the fuel level is below the threshold. The presence of fuel at the clean side also ensures that the pump is not starved of fuel and there will be no engine startability issue.

[00017] The weight 207 is adapted to be displaced in a manner such that the weight 207 maintains the ball in a second operative position. The weight 207 is displaced such that the weight 207 moves upwards when the fuel level in the dirt side is greater than or equal to a threshold. This makes the weight 207 to maintain the ball in the second operative position. The ball movable within the receiving element 208 closes the opening 204 when the ball is in the second operative position. The air in the dirt side is not allowed to pass through the opening 204 as the ball closes the opening 204 when the fuel level is equal or above the threshold. This also prevents the fuel in the dirt side pass through the opening 204. Thus, the fuel filter reduces the intermixing of the fuel from the dirt side with the fuel in the clean side.

[00018] 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.