Claims:We Claim:
1. A pump (200) in a fuel injection system, said pump (200) comprising:
at least one cylinder (201) located in said pump (200); said cylinder (201) having one end connected to a metering unit (202) and the other end connected to a high pressure rail (203)` ;
at least one inclined bore (204) in a pump(200); said inclined bore (204) having one end connected to said cylinder (201) and other end connected to said metering unit (202).

2. The pump (200) as claimed in claim 1, wherein said cylinder (201) receives the fuel from metering unit (202) and sends to high-pressure rail (203).

3. The pump (200) as claimed in claim 1, wherein said inclined bore (204) receives the excess fuel from said cylinder (201) and communicates the fuel to the fuel tank.

4. The pump (200) as claimed in claim 1, wherein a throttle (205) is located inside said inclined bore (204).
, 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] The invention relates to a pump in a fuel injection system

Background of the invention
[0002] In common rail fuel injection system; fuel is sucked from the tank by a pump mounted on a high-pressure pump to deliver the fuel to the high-pressure assembly. The excess fuel flows back to the tank via an overflow valve. The metering unit is used to meter the exact desired quantity of fuel used in the engine operating state to a high-pressure pump.

[0003] The prior art patent application US6446606B1 discloses a fuel injection system for internal combustion engines, has a distributor tube and a high-pressure pump that is driven as a function of engine rpm and that serves to generate the fuel pressure and throughput required in the distributor tube in the applicable operating state of the engine. The system also includes a fuel-metering unit, which is associated with the high-pressure pump and includes a regulating valve, which is actuated electromagnetically. The fuel-metering unit is disposed in the high-pressure pump, and the outlet of the regulating valve discharges into the low-pressure region of the high-pressure pump. The above design features make a fuel-metering unit possible that is capable of metering the exact quantity of fuel desired in the applicable engine operating state to the high-pressure pump of the CR system.

Brief description of the accompanying drawings:
[0004] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawings:

[0005] FIG. 1 illustrates a pump assembly according to an embodiment in the invention; and

[0006] FIG. 2 illustrates a cross section of a pump assembly according to an embodiment in the invention.

Detailed description of the embodiments
[0007] Figure 1 illustrates a pump 200 in a fuel injection system in accordance to an embodiment of the disclosure. The pump 200 comprises at least one cylinder 201 located in the pump 200. The cylinder 201 having one end connected to a metering unit 202 and the other end connected to a high-pressure rail 203. The pump 200 further comprises at least one inclined bore 204 in the pump 200. The inclined bore 204 having one end connected to the cylinder 201 and other end connected to the metering unit 202.

[0008] The metering unit 202 decides the quantity of the fuel used in the pump 200 during the operating stage of the pump 200. In the pump 200, the cylinder 201 receives the fuel from metering unit 202 and sends to high-pressure rail 203. The fuel from the metering unit 202 flows to the cylinder 201 and then to the high-pressure rail 203.

[0009] Here the inclined bore 204 receives the excess fuel from the cylinder 201 and communicates the fuel to the fuel tank. The excess fuel refers to the over flow fuel or the backflow fuel from the cylinder 201 when the metering unit 202 is in non-operating condition. The backflow of the fuel is due to the clearance between the components of the metering unit 202 and from the cylinder 201.

[0010] Figure 2 illustrates a cross section 200a of the pump 200 in accordance to an embodiment of the disclosure. A throttle plug 205 is located inside the inclined bore 204. It facilitates the passage of leaked fuel from cylinder 201 to backflow line in the common rail fuel injection system. Press fit in the inclined bore 204 locates the throttle plug 205.

[0011] According to an embodiment of the disclosure, the inclined bore 204 is at any angle is drilled in the pump 200 housing for press fit assembly of the throttle plug 205. The throttle plug 205 will ensure the fuel passage to overflow inclined bore 204.

[0012] The fuel injection system here includes the common rail injection system. A pump mounted on a high-pressure pump sucks the fuel. The pump delivers the fuel to the metering unit 202 and from the metering unit 202 the fuel is delivered to the high-pressure assembly 203 via pump 200. From the high-pressure assembly 203 the fuel is delivered to the injector and then to the combustion chamber of the engine. At an instance when the metering unit 202 is closed, there are leakages that are not supposed to flow to the high-pressure assembly 203. Therefore, as disclosed in the disclosure above, the inclined bore 204 is made in the pump 200 housing and the fuel flows to the inclined bore 204 and communicates to the fuel tank.

[0013] Here in the disclosure, disclosed above, the inclined bore 204 is connected to any number of cylinders 201 in the pump 200and not restricted to one cylinder 201. The passage for the fuel is in series so that the overflow fuel flows into a common passage to the inclined bore 204. The pressure difference is the source for overflow fuel to flow into the passage. The pressure in the overflow fuel is always higher than the atmospheric pressure, which becomes the medium for the fuel to flow towards the inclined bore 204.

[0014] The use of inclined bore 204 into the pump housing eliminates the throttle connector in the pump 200 and the connecting pipe to the backflow in the common rail injector at the vehicle. The inclined bore 204 in the pump 200 makes the common rail injection system less complex for its usage.

[0015] ‘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.

[0016] 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.