CLIAMS:We Claim:

1. A conduit (12) for supplying fuel to a high pressure pump (14) of a fuel injection system, said conduit (12) comprising:
an upstream end (16) in flow communication with an overflow outlet of a fuel injector (18), said conduit (12) adapted to channel excess fuel discharged from said fuel injector (18); characterized in that
a downstream end (20) in flow communication with an inlet (22) of said high pressure pump (14), said conduit (12) adapted to supply fuel from said fuel injector (18) to said inlet (22) of said high pressure pump (14).
2. The conduit (12) for supplying fuel to a high pressure pump (14) of a fuel injection system in accordance with Claim 1 wherein said downstream end (20) of said conduit (12) is in flow communication with said inlet (22) of said high pressure pump (14) via a coupling mechanism.
3. A fuel injection system (10), said fuel injection system (10) comprising:
a high pressure pump (14);
a fuel injector (18); characterized in that
a conduit (12) comprising an upstream end (16) and a downstream end (20), said upstream end (16) in flow communication with an overflow outlet of said fuel injector (18), said downstream end (20) in flow communication with an inlet (22) of said high pressure pump (14), said conduit (12) adapted to supply fuel discharged from said fuel injector (18) to said inlet (22) of said high pressure pump (14).
,TagSPECI:Field of the invention:

[0001] This invention relates to a conduit for supplying fuel to a high pressure pump and a fuel injection system thereof.

Background of the invention:

[0002] Fuel from a fuel tank of an internal combustion engine is supplied to a high pressure pump via a low pressure pump also known as a fuel metering pump and a fuel filter. The high pressure pump is coupled to a high pressure common rail, wherein the high pressure common rail is further operatively coupled to a series of fuel injectors. Fuel from the low pressure pump is channelled to the high pressure pump, wherein the fuel is then progressively channelled to the fuel injectors via the high pressure common rail and discharged therein. The excess fuel from the fuel injectors is channelled to the fuel tank. The excess fuel from the fuel injectors contain carbon particles that clog the fuel filter when fresh fuel is drawn from the fuel tank. Therefore, a solution is proposed wherein fuel containing carbon particles is supplied from the fuel injectors directly to the high pressure pump via a conduit.

[0003] Chinese Patent Publication Number 203308626-U describes a fuel oil supply system for a diesel engine cylinder. The system comprises a fuel oil tank, oil transfer pump, a filter, an oil injection pump, and a fuel injector, in which the oil outlet of the oil injection pump is connected with the fuel injector through a high pressure oil pipe. The oil inlet of the oil injection pump is connected with an overflow valve and an oil return pipe to the fuel oil tank. One side of the fuel oil through an oil outlet pipe is connected with a oil filter inlet. The oil outlet of the oil filter is connected with the oil inlet of the oil transfer pump. The oil transfer pump is connected with the oil inlet of the oil injection pump by a pipe. Through improvement, the utility model makes the fuel flow through the oil filter and then enters the oil transfer pump.

Brief description of the accompanying drawing:
[0004] An exemplifying embodiment of the invention is explained in principle below with reference to the drawing. The drawing is:
[0005] Figure 1 illustrates a front view depicting a conduit for supplying fuel from a fuel injector to a high pressure pump of a vehicle.

Detailed description of the invention:
[0006] Figure 1 depicts a conduit 12 for supplying fuel to a high pressure pump 14 of a fuel injection system 10. The conduit 12 comprises an upstream end 16 in flow communication with an overflow outlet of a fuel injector 18, the conduit 12 adapted to channel excess fuel discharged from the fuel injector 18. A downstream end 20 is in flow communication with an inlet 22 of the high pressure pump 14, the conduit 12 adapted to supply fuel from the fuel injector 18 to the inlet 22 of the high pressure pump 14.

[0007] A fuel injection system 10 is also described. The fuel injection system 10 comprises a high pressure pump 14 and a fuel injector 18. A conduit 12 comprises an upstream end 16 and a downstream end 20, the upstream end 16 in flow communication with an overflow outlet of the fuel injector 18. The downstream end 20 is in flow communication with an inlet 22 of the high pressure pump 14, the conduit 12 adapted to supply fuel discharged from the fuel injector 18 to the inlet 22 of the high pressure pump 14.

[0008] A fuel inlet passageway 24 is coupled to the low pressure pump 26 to channel fuel from a vehicle fuel tank 28 to a fuel filter 30. The low pressure pump 26 increases a pressure and therefore controls the flow of fuel supplied through the fuel inlet passageway 24. The low pressure pump 26 increases the pressure and therefore controls the flow of fuel supplied through the fuel inlet passageway 24 to the fuel filter 30. In an embodiment, low pressure pump 26 is a manual/automated flow rate adjustable pump that controls the flow rate of fuel from the fuel tank 28 to the fuel filter 30.

[0009] In an embodiment, the fuel filter 30 receives fuel from the low pressure pump 26 via the fuel inlet passageway 24. The impurities that are present in the fuel channeled from the low pressure pump 26 is filtered in the fuel filter 30 prior to the fuel being discharged to an outlet of the fuel filter 30. More specifically, dust particles, grime, carbon deposits, and any other insoluble impurities that are present in the fuel are filtered in the fuel filter 30, such that pure fuel is discharged through the fuel inlet passageway 32 that is coupled to an outlet of the fuel filter 30.

[00010] In an embodiment, high pressure pump 14 channels fuel received from the fuel filter 30 to the fuel injector 18 through a first outlet of the high pressure pump 14. Specifically, the high pressure pump 14 channels fuel to the fuel injector 18 via a high pressure common rail 34 by means of the fuel inlet passageway 36. High pressure pump 14 increases the pressure and therefore control the flow of fuel supplied through the fuel inlet passageway 36 to the fuel injector 18 via the high pressure common rail 34. In an embodiment, high pressure pump 14 is a manual/automated flow rate adjustable pump that controls the flow rate of fuel from the fuel filter 30 to the fuel injector 18 via the high pressure common rail 34.

[00011] The excess fuel in the high pressure pump 14 is recirculated to the fuel tank 28 through a fluid recirculation path 40 and discharged there through. An upstream end of the fluid recirculation path 40 is in flow communication with an inlet of the high pressure pump 14, and a downstream end of the fluid recirculation path 40 is in flow communication to the fuel tank 28.

[00012] The fuel injection system 10 includes an engine control unit 42. The engine control unit 42 is coupled to the low pressure pump 26 via a control flow path. Engine control unit 42 controls the low pressure pump 26 to facilitate channeling fuel to the fuel injector 18 from the fuel tank 28. In an embodiment, engine control unit 42 facilitates channeling a metered quantity of fuel from the fuel tank 28 to the fuel injector 18 to maintain a controlled flow of fuel from the fuel tank 28.

[00013] A conduit 12 is in flow communication between the fuel injector 18 and the high pressure pump 14. Specifically, an upstream end of the conduit 12 is in flow communication with an overflow outlet 16 of the fuel injector 18, while a downstream end 20 of the conduit 12 is in flow communication with an inlet 22 of the high pressure pump 14. The conduit 12 facilitates channeling fuel that overflows from the fuel injector 18 to the inlet 22 of the high pressure pump 14. In an embodiment, each overflow outlet of each fuel injector that delivers fuel in the fuel injection system 10 is in flow communication with the conduit 12 and delivers fuel to the inlet 22 of the high pressure pump 14.

[00014] The operation of the fuel injection system 10 is now described as an example. When the vehicle is in an operative state, fuel is channeled to the high pressure pump 14 from the fuel tank 28 via the fuel filter 30. From the high pressure pump 14, the pressurized fuel is supplied to the high pressure common rail 34 via the fuel inlet passageway 36. Pressurized fuel from the high pressure common rail 34 is supplied to the fuel injector 18 and discharged into an engine cylinder. Excess fuel from the fuel injector 18 that is not discharged into the engine cylinder is supplied to the inlet 22 of the high pressure pump 14.

[00015] Therefore, by supplying fuel to the inlet 22 of the high pressure pump 14 from the fuel injector 18, the fuel containing carbon particles is not supplied and mixed with the fuel in the fuel tank 28. Hence, the excess fuel from the fuel injector 18 is prevented from contaminating the fuel present in the fuel tank 28. As a consequence, a life of the fuel filter 30 is extended substantially.

[00016] The above described conduit 12 for supplying fuel to a high pressure pump 14 of a vehicle is cost effective and highly reliable. The conduit 12 for supplying fuel to a high pressure pump 14 of a vehicle facilitates fuel from the fuel injector 18 to be delivered to the high pressure pump 14 via the conduit 12. In addition, the modular nature of each sub-system of the fuel injection system 10 facilitates easy disassembly and replacement of individual system components as required.

[00017] It must be understood that the embodiments explained in the above detailed description in only illustrative to explain the working of the conduit 12 for supplying fuel to a high pressure pump 14 of a vehicle as claimed and does not limit the scope of this invention. Though the figures shown in the specification has only one fuel injector, this scope of this disclosure can be extended to a fuel injection system comprising any number of fuel injectors. The scope of this disclosure is limited only by the scope of the claims. Many modification and changes in the embodiments aforementioned are envisaged and are within the scope of this invention.