Claims:We Claim

1. A high pressure fuel pump (10), said high pressure fuel pump (10) comprising:
a housing (12);
a barrel (13) positioned within said housing (12), and secured within said housing (12);
a plunger (14) positioned within said barrel (13), said plunger (14) adapted to reciprocate within said barrel (13) to facilitate channeling pressurized fuel to a fuel injector (24); characterized in that
an axial bore (16) defined through said barrel (13), a first end of the axial bore (16) in flow communication with a pumping chamber (18) that is defined within said barrel (13), an opposite second end of the axial bore (16) in flow communication with an outer sidewall of said housing (12) of said high pressure fuel pump (10);
a fuel injector (20) inserted within the axial bore (16) defined through said barrel (13) such that the bore (22) of the fuel injector (24) that delivers pressurized fuel is positioned proximate to the pumping chamber (18) that is defined within said barrel (13) and is in flow communication with the pumping chamber (18) that is defined within said barrel (13).

2. The high pressure fuel pump (10) in accordance with Claim 1, wherein an opposite end of the fuel injector (20) is in flow communication with a fuel supply pipe (25) for supplying pressurized fuel to the fuel injector (20).

3. The high pressure fuel pump (10) in accordance with Claim 2, wherein the fuel supply pipe (25) comprises an upstream end and a downstream end, the upstream end of the fuel supply pipe (25) in flow communication with a high pressure line (26) that supplies pressurized fuel from the pumping chamber (18) of the high pressure fuel pump (10) to a fuel injector (24) of an engine, the downstream end of the fuel supply pipe (25) in flow communication with the opposite end of the fuel injector (20) and adapted to supply pressurized fuel to the fuel injector (20).

4. The high pressure fuel pump (10) in accordance with Claim 3, wherein the fuel supply pipe (25) comprises a one way flow control valve (28) in flow communication with the fuel supply pipe (25), the one way flow control valve (28) adapted to deliver pressurized fuel from the high pressure line (26) that supplies pressurized fuel from the pumping chamber (18) of the high pressure fuel pump (10) to the fuel injector (24) of the engine to the fuel injector (20).

5. The high pressure fuel pump (10) in accordance with Claim 1, wherein an engine control unit (35) is in electronic communication with a solenoid valve that is defined in said fuel injector (24), the engine control unit (35) adapted to actuate the solenoid valve that is defined in said fuel injector (24) for a pre-determined time interval to facilitate injecting a metered quantity of pressurized fuel into the pumping chamber (18) that is defined within said barrel (13) of said high pressure fuel pump (10).

6. The high pressure fuel pump (10) in accordance with Claim 5, wherein the engine control unit (35) is adapted to actuate the solenoid valve that is defined in said fuel injector (24) for a lower pre-determined time interval to facilitate injecting a lower metered quantity of pressurized fuel into the pumping chamber (18) that is defined within said barrel (13) of said high pressure fuel pump (10).
7. The high pressure fuel pump (10) in accordance with Claim 5, wherein the engine control unit (35) is adapted to actuate the solenoid valve that is defined in said fuel injector (24) for a higher pre-determined time interval to facilitate injecting a greater metered quantity of pressurized fuel into the pumping chamber (18) that is defined within said barrel (13) of said high pressure fuel pump (10).
, 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 high pressure fuel pump, and more specifically to a fuel injector for delivering pressurized fuel to an pumping chamber of a high pressure fuel pump.

Background of the invention
[0002] CN 109113885 A describes a fuel injection rate variable diesel fuel injection system and method for a diesel engine. The system comprises a high-pressure fuel pump, a low-pressure fuel rail, a high-pressure fuel rail, a first electric control fuel injector, a second electric control fuel injector, a one-way valve and an ECU. The high-pressure fuel pump is connected with the low-pressure fuel rail and the high-pressure fuel rail. The first electric control fuel injector is arranged above an engine combustor. The second electric control fuel injector is arranged in a pipeline between the high-pressure fuel rail and the first electric control fuel injector. The one-way valve is arranged in a pipeline between the low-pressure fuel rail and the first electric control fuel injector. The ECU is connected with the high-pressure fuel pump, the low-pressure fuel rail, the high-pressure fuel rail, the first electric control fuel injector and the second electric control fuel injector through wires. By means of the fuel injection rate variable diesel fuel injection system and method for the diesel engine, the fuel injection pressure is changed in the single fuel injection process by adoption of the two fuel rails and the two single-cylinder electric control fuel injectors while independence of diesel fuel injection pressure from the engine rotation speed is achieved, and finally the ideal continuously and flexibly variable fuel injection rate is obtained.

Brief description of the accompanying drawing
[0003] Figure 1 illustrates a high pressure fuel pump illustrating a fuel injector integrated therein in one embodiment of the invention.
Detailed description of the embodiments
[0004] A high pressure fuel pump 10 is described. The high pressure fuel pump 10 comprises a housing 12. A barrel 13 is positioned within the housing 12, and secured within the housing 12. A plunger 14 is positioned within the barrel 13, the plunger 14 adapted to reciprocate within the barrel 13 to facilitate channeling pressurized fuel to a fuel injector 24. An axial bore 16 is defined through the barrel 13. A first end of the axial bore 16 is in flow communication with a pumping chamber 18 that is defined within the barrel 13. An opposite second end of the axial bore 16 is in flow communication with housing 12 of the high pressure fuel pump 10. A fuel injector 20 is inserted within the axial bore 16 defined through the barrel 13 such that the bore 22 of the fuel injector 20 that delivers pressurized fuel is positioned proximate to the pumping chamber 18 that is defined within the barrel 13. In addition, the bore 22 of the fuel injector 20 that delivers pressurized fuel is in flow communication with the pumping chamber 18 that is defined within the barrel 13.

[0005] Figure 1 illustrates a high pressure fuel pump 10 illustrating a fuel injector 20 integrated therein in one embodiment of the invention. The high pressure fuel pump 10 comprises a housing 12. In an exemplary embodiment, a barrel 13 is positioned within the housing 12, and is secured within the housing 12. A plunger 14 is positioned within the barrel 13. More specifically, the reciprocatory motion of the plunger 14 within the barrel 13 facilitates channeling pressurized fuel to a fuel injector 24. From the fuel injector 24, the pressurized fuel is delivered to an engine. In an exemplary embodiment, an axial bore 16 is defined through the barrel 13, and extends from one end of the barrel 13 to an opposite second end of the housing 12. More specifically, a first end of the axial bore 16 is in flow communication with a pumping chamber 18 that is defined within the barrel 13. An opposite second end of the axial bore 16 is in flow communication with housing 12 of the high pressure fuel pump 10.
[0006] In an exemplary embodiment, a fuel inlet port 40 is defined in the barrel 13. More specifically, a first end of the fuel inlet port 40 is in flow communication with the pumping chamber 18 of the high pressure fuel pump 10. An opposite second end of the fuel inlet port 40 is in flow communication with a fuel gallery of the high pressure fuel pump 10. When the plunger 14 is translated from its top dead center position to its bottom dead center position, pressurized fuel is channeled into the pumping chamber 18 of the high pressure fuel pump 10 from the fuel gallery. Similarly, when the plunger 14 is translated to its top dead center position and begins its descent towards its bottom dead center position, the residual fuel from the pumping chamber 18 is channeled into the fuel gallery via the fuel inlet port 40.

[0007] In an exemplary embodiment, a fuel injector 20 is inserted within the axial bore 16 that is defined through the barrel 13. More specifically, the bore 22 of the fuel injector 20 that delivers pressurized fuel to the pumping chamber 18 is positioned proximate to the pumping chamber 18 that is defined within the barrel 13. More specifically, the bore 22 of the fuel injector 20 that delivers pressurized fuel is in flow communication with the pumping chamber 18 that is defined within the barrel 13 to deliver pressurized fuel to the pumping chamber 18 that is defined within the barrel 13. An opposite end portion of the fuel injector 20 is in flow communication with a fuel supply pipe 25, and receives pressurized fuel from the fuel supply pipe 25. The pressurized fuel that is received from the fuel supply pipe 25 is delivered from the fuel injector 20 to the pumping chamber 18 that is defined in the barrel 13.

[0008] The fuel supply pipe 25 comprises an upstream end and a downstream end. The upstream end of the fuel supply pipe 25 is in flow communication with a high pressure line 26 that supplies pressurized fuel from the pumping chamber 18 of the high pressure fuel pump 10 to a fuel injector 24 of an engine. The downstream end of the fuel supply pipe 25 is in flow communication with the opposite end of the fuel injector 24, and is adapted to supply pressurized fuel to the fuel injector 24. In addition, the fuel supply pipe 25 comprises a one way flow control valve 28 that is in flow communication with the fuel supply pipe 25. In an exemplary embodiment, the one way flow control valve 28 is adapted to deliver pressurized fuel from the high pressure line 26 that supplies pressurized fuel from the pumping chamber 18 of the high pressure fuel pump 10 to the fuel injector 24 of the engine to the fuel injector 20 that is inserted within the axial bore 16 that is defined through the barrel 13. Therefore, the pressurized fuel that is delivered from the high pressure line 26 to the fuel injector 20 that is inserted within the axial bore 16 that is defined through the barrel 13 is delivered to the pumping chamber 18 of the high pressure fuel pump 10.

[0009] In an exemplary embodiment, an engine control unit 35 is in electronic communication with the fuel injector 20. More specifically, the engine control unit 35 is in electronic communication with a solenoid valve that is defined in the fuel injector 20. When the solenoid valve that is defined in the fuel injector 20 is actuated, pressurized fuel is delivered from the high pressure line 26 to the pumping chamber 18 of the high pressure fuel pump 10 via the fuel supply pipe 25 and via the fuel injector 20. The engine control unit 35 is adapted to actuate the solenoid valve that is defined in the fuel injector 20 for a pre-determined time interval. The actuation of the solenoid valve by the engine control unit 35 for the pre-determined time interval facilitates injecting a metered quantity of pressurized fuel into the pumping chamber 18 that is defined within the barrel 13 of the high pressure fuel pump 10. More specifically, when the solenoid valve that is defined in the fuel injector 20 is actuated by the engine control unit 35 for a lower pre-determined time interval, a lower quantity of pressurized fuel is injected by the fuel injector 20 into the pumping chamber 18 that is defined within the barrel 13 of the high pressure fuel pump 10.

[0010] A working of the high pressure fuel pump 10 is described as an example. In the current system layout, as the plunger 14 of the high pressure fuel pump 10 is translated towards its top dead center position from its bottom dead center position, pressurized fuel from the pumping chamber 18 is channeled into the fuel gallery via the fuel inlet port 40. This process of fuel flow to the fuel gallery from the pumping chamber 18 continues until the fuel inlet port 40 is completely closed by a top portion of the plunger 14. Consequently, a quantity of fuel that exists within the pumping chamber 18 between the fuel inlet port 40 and a top of the pumping chamber 18 is reduced, as the plunger 14 continues its ascent towards its top dead center position. At higher engine speeds and loads, when it is required to deliver a higher quantity of pressurized fuel from the high pressure fuel pump 10 to the fuel injector 24, the actual quantity of pressurized fuel that is delivered from the pumping chamber 18 to the high pressure line 26 via the fuel delivery valve of the high pressure fuel pump 10 is lower than the quantity of fuel that is required to be delivered to the high pressure line 26. This is because the actual quantity of pressurized fuel that exists within the pumping chamber 18 is reduced as a consequence of the fuel being channeled out of the pumping chamber 18 to the fuel gallery via the fuel inlet port 40. Therefore, the excess fuel that is required to be delivered to the high pressure line 26 from the high pressure fuel pump 10 is injected into the pumping chamber 18 via the fuel injector 20.

[0011] The one way flow control valve 28 is in flow communication with the high pressure line 26 and receives pressurized fuel from the high pressure line 26. The downstream end of the one way flow control valve 28 is in flow communication with the fuel injector 20. This fuel injector 20 is inserted into the axial bore 16 of the high pressure fuel pump 10 via the pump housing 12, and delivers pressurized fuel to the pumping chamber 18 of the high pressure fuel pump 10. The engine control unit 35 is electronically connected to the solenoid valve of the fuel injector 20, and actuates the solenoid valve of the fuel injector 20 for an empirically pre-determined time interval to facilitate channeling pressurized fuel from the fuel injector 20 to the pumping chamber 18 of the high pressure fuel pump 10. At higher pump speeds and loads, as soon as the fuel inlet port 40 is closed by the top portion of the plunger 14, the engine control unit 35 actuates the solenoid valve of the fuel injector 20. Pressurized fuel remaining in the high pressure line 26 after fuel delivery to the fuel injector 24 of the engine is channeled through the one way flow control valve 28 and supplied to the fuel injector 20 by means of the fuel supply pipe 25. Pressurized fuel from the fuel injector 20 is delivered into the pumping chamber 18 until the quantity of pressurized fuel within the pumping chamber 18 increases to a required predetermined quantity. More specifically, at a specific pump speed and load, the engine control unit 35 actuates the solenoid valve of the fuel injector 20 for a first empirically pre-determined time interval until the quantity of pressurized fuel in the pumping chamber 18 increases to the required predetermined quantity. As the pump speed and load is increased beyond this level, the engine control unit 35 actuates the solenoid valve for a second empirically pre-determined time interval that is greater than the first empirically pre-determined time interval until the quantity of pressurized fuel in the pumping chamber 18 increases to a required predetermined quantity that corresponds to the increased pump speed and load.

[0012] Therefore, the quantity of pressurized fuel that is delivered by the fuel injector 20 into the pumping chamber 18 of the high pressure fuel pump 10 via the one way flow control valve 28 as the fuel inlet port 40 is closed by means of the top portion of the plunger 14 can be varied depending on the pump speed and pump load. At lower pump speeds and loads, as the quantity of pressurized fuel that is required to be delivered from the pumping chamber 18 of the high pressure fuel pump 10 to the high pressure line 26 via the fuel delivery valve of the high pressure fuel pump 10 is lower, the empirically pre-determined time interval for which the solenoid valve of the fuel injector 20 is actuated by the engine control unit 35 is correspondingly lower to ensure that a lower quantity of pressurized fuel in the pumping chamber 18 is injected by the fuel injector 20. Similarly, as the pump speed and pump load is increased beyond this limit, as the quantity of pressurized fuel that is required to be delivered from the pumping chamber 18 of the high pressure fuel pump 10 to the high pressure line 26 via the fuel delivery valve of the high pressure fuel pump 10 is higher, the empirically pre-determined time interval for which the solenoid valve of the fuel injector 20 is actuated by the engine control unit 35 is correspondingly higher to ensure that a higher quantity of pressurized fuel in the pumping chamber 18 is injected by the fuel injector 20 that corresponds to the increased pump speed and load.

[0013] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the scope of the claims.