Claims:We Claim:
1. A method of controlling flow of fuel in a fuel injection system, said fuel injection system comprising, a low pressure circuit comprising a fuel tank, a fuel filter, an overflow valve, a high pressure pump, and an electromagnetic valve located in between said fuel filter and said fuel tank, and in flow communication with said fuel tank and said high pressure pump, said method comprising:

detecting (100), by a control unit an operating condition of said high pressure pump;

verifying (102), by said control unit if said operating condition corresponds to first filling of fuel into said high pressure pump; and

actuating (104), by said control unit, said electromagnetic valve for enabling fuel to flow of fuel from said fuel filter into said high pressure pump.

2. The method of claim 1, further comprising de-actuating (106),by said control unit said electromagnetic valve upon completion of first filling of fuel into said high pressure pump.
, 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 method of controlling a flow of fuel in a fuel injection system.

Background of the invention
[0002]In a fuel injection system a high pressure pump is used to pressurize fuel before the fuel is delivered to the injector for injection into the engine cylinders. During first start of the high pressure pump, the air that is located in the high pressure pump needs to be flushed out, this is usually done by circulating fuel at a pressure that is higher than that required for normal working of the high pressure pump. However, an overflow valve that is located upstream to the high pressure pump prevents fuel from entering the high pressure pump as this overflow valve opens a path for the fuel to flow back to the fuel tank, leading to improper flushing of air from the high pressure pump.

Brief description of the accompanying drawing
[0003] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

[0004] FIG. 1 illustrates a method of controlling flow of fuel in a fuel injection system.

Detailed description of the embodiments
[0005] FIG. 1 illustrates a method of controlling flow of fuel in a fuel injection system. The fuel injection system comprises, a low pressure circuit comprising a fuel tank, a fuel filter, an overflow valve, a high pressure pump, and an electromagnetic valve located in between the fuel filter the fuel tank, and in flow communication with the fuel tank and the high pressure pump. The method comprises detecting (100), by a control unit an operating condition of the high pressure pump. The control unit verifies 102 if the operating condition corresponds to first filling of fuel into the high pressure pump, and actuates (104) the electromagnetic valve for enabling fuel to flow of fuel from the fuel filter into the high pressure pump.

[0006]The working of the fuel injection system will be explained in further detail. The fuel injection system disclosed herein is used for injecting fuel into the engine cylinder. The fuel injection system comprises a low pressure circuit comprising a fuel tank to store fuel, fuel from the fuel tank flows through the fuel filter and then enters the high pressure pump via an overflow valve. An electromagnetic valve is located in between the fuel filter and the fuel tank. The location of the electromagnetic valve is such that in a first position the electromagnetic valve allows fuel to flow from the fuel filter and into the high pressure pump and in a second position allows fuel to flow from the fuel filter back to the fuel tank.

[0007]The working of the above mentioned will be explained in further detail. The method comprises detecting (100), by a control unit an operating condition of the high pressure pump. The control unit verifies 102 if the operating condition corresponds to first filling of fuel into the high pressure pump. The electromagnetic valve is actuated 104 by the control unit for enabling fuel to flow of fuel from the fuel filter into the high pressure pump. The time for first filling is decided by the control unit based upon the type of high pressure pump. Upon completion of first filling the control unit de-actuates 106 the electromagnetic valve for enabling fuel to flow of fuel from the fuel filter into the high pressure pump.
[0008]By using the above mentioned the problem of lack of pressure during first filling of high pressure pump can be avoided.

[0009] ‘Adapted’ or ‘arranged’, in the context of the instant disclosure, refers to the technical capability or the technical capacity of a component, in relation to which the term ‘adapted’ or ‘arranged’ is used, to carry out or executed a specified action or actions, upon the requirement of the specified action or actions to be carried out or executed. Moreover, the usage of the term ‘adapted’ or ‘arranged’ here, is in reference with the normal technical capability or technical capacity of the component, imparted by the design or the structure or the composition of the component, and not in reference with any special or extraneous capability or capacity, beyond the scope of the normal technical capability or technical capacity. Therefore there is a need to address this problem.

[0010]It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention in terms of the type of high pressure pump used. 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.