Field of the invention
[0001] This invention relates to a high pressure fuel pump, and more specifically to a spring loaded valve for the high pressure fuel pump.
Background of the invention
[0002] CN 202746179 U describes a utility model for electric hydraulic pumps, including the motor and the pump. The pump includes a suction pipe, a low pressure pump assembly, a high pressure pump assembly, oil pump and valve block assembly, and a cam assembly. One end of the suction pipe has a strainer, the strainer immersed in the fuel tank of hydraulic oil, the other end of the suction pipe and the low- pressure pump assembly are in communication. A low-pressure pump assembly includes a low-pressure pump body, a low pressure pump wheel, a low pressure pump rollers, and a cam holder. The high-pressure pump assembly includes a high pressure pump body and a one-way valve. The high-pressure pump has three pump plungers, and a preload spring plunger disposed uniformly on the high pressure valve body, and the spring preload settings. On the high-pressure valve spring seat hole center, a preload spring placed ball is positioned. The one-way inlet valve is equipped with a three-way valve and a three-way valve oil. The utility model has high volumetric efficiency, small leakage, and can work under high pressure. The features constitute a reasonable layout, compact structure, and easy matching with similar products.
Brief description of the accompanying drawing
[0003] Figure 1 illustrates a high pressure fuel pump illustrating a spring loaded valve for the high pressure fuel pump.

Detailed description of the embodiments
[0004] Figure 1 illustrates a high pressure fuel pump 10. The high pressure fuel pump 10 comprises a pump housing 12, the pump housing 12 comprising a barrel 16 defined within the pump housing 12. A plunger 14 is positioned within the barrel 16, the plunger 14 adapted to reciprocate within the barrel 16 and deliver pressurized fuel from the high pressure fuel pump 10 to a fuel injector. A spring chamber 18 is defined within the pump housing 12, the spring chamber 18 adapted to house a spring 20 therein. A horizontal bore 22 is defined through a wall of the pump housing 12, a first end of the horizontal bore 22 in flow communication with the spring chamber 18 defined within the pump housing 12, an opposite second end of the horizontal bore 22 in flow communication with an outer sidewall of the pump housing 12. A spring loaded valve 24 is positioned within the horizontal bore 22, the spring loaded valve 24 adapted to channel a unidirectional flow of fuel from the spring chamber 18 out of the high pressure fuel pump 10.
[0005] In an exemplary embodiment, the high pressure fuel pump 10 comprises a pump housing 12. The pump housing 12 comprises a barrel that is defined within the pump housing 12. In an exemplary embodiment, the barrel may be an integral portion of the pump housing 12 and therefore integrated within the pump housing 12. A plunger 14 is positioned within the barrel, wherein the plunger 14 is adapted to reciprocate within the barrel. The reciprocation motion of the plunger 14 facilitates delivering pressurized fuel from the high pressure fuel pump 10 to a fuel injector, for injecting the pressurized fuel therein to an engine. In an exemplary embodiment, a spring chamber 18 is defined within the pump housing 12. The spring chamber 18 is adapted to house a spring 20 therein and allows for the reciprocation of the plunger 14 of the high pressure fuel pump 10.

[0006] In an exemplary embodiment, a horizontal bore 22 is defined through a wall of the pump housing 12. More specifically, a first end of the horizontal bore 22 is in flow communication with the spring chamber 18 that is defined within the pump housing 12 and is adapted to receive pressurized fuel that is channeled from the spring chamber 18. The opposite second end of the horizontal bore 22 is in flow communication with an outer sidewall of the pump housing 12. A first end of the horizontal bore 22 comprises a solid portion 26 of the pump housing 12 that extends within the horizontal bore 22. The solid portion 26 is a constituent of the pump housing 12, and extends within the horizontal bore 22. More specifically, the solid portion 26 that extends within the horizontal bore 22 extends to a known pre-determined length within the horizontal bore 22, and culminates within the horizontal bore 22. In the exemplary embodiment, the solid portion 26 of the pump housing 12 comprises a bore 28 defined there through. Therefore, the bore 28 that is defined through the solid portion 26 of the pump housing 12 comprises a first end and an opposite second end. The first end of the bore 28 is in flow communication with the spring chamber 18, and the opposite second end of the bore 28 is in flow communication with the horizontal bore 22. Therefore, the fuel that is present within the spring chamber 18 flows into the horizontal bore 22 via the bore 28 that is defined through the solid portion 26 of the pump housing 12.
[0007] In an exemplary embodiment, a spring loaded valve 24 is positioned within the horizontal bore 22. Therefore, the spring loaded valve 24 is adapted to channel a unidirectional flow of fuel from the spring chamber 18 out of the high pressure fuel pump 10. The spring loaded valve 24 comprises a plug portion 30 that is positioned against the bore 28 that is defined in the solid portion 26. A spring member 32 is positioned against the plug portion 30 at one end, while an opposite second end of the spring member 32 is secured to a valve head 34. An end of the valve head 34 is inserted within the horizontal bore 22 to facilitate closing the horizontal bore 22. Once the

horizontal bore 22 is closed by inserting the valve head 34 within the horizontal bore 22, a flow of fuel from outside the high pressure fuel pump 10 is prevented from entering the spring chamber 18 via the horizontal bore 22.
[0008] In the exemplary embodiment, the valve head 34 comprises a bore 36 defined there through such that the first end of the bore is in flow communication with the horizontal bore 22. An opposite second end of the bore 36 is in flow communication with a sidewall of the valve head 34 to facilitate channeling lubrication oil from the spring chamber 18 to the sidewall of the valve head 34 via the horizontal bore 36. Once the spring loaded valve 24 is inserted within the horizontal bore 22, the flow of lubrication oil from outside the housing 12 of the high pressure fuel pump 10 to the spring chamber 18 via the horizontal bore 22 is prevented.
[0009] A working of the spring loaded valve 24 that is inserted within the horizontal bore 22 is described as an example. When the plunger 14 that is positioned within the barrel of the high pressure fuel pump 10 reciprocates, pressurized fuel is delivered from the high pressure fuel pump 10 to a fuel injector. At the end of the forward stroke of the plunger 14 of the high pressure fuel pump 10, the spring 20 that is located in the spring chamber 18 facilitate applying a restoring force on the roller tappet. As the plunger 14 translates away from its top dead center, the fuel that is present in the space contained by the spring chamber 18 is compressed. Therein, the compressed fuel causes the plug portion 30 of the spring loaded valve 24 to translate against the force of the spring member 32. Once the plug portion 30 of the spring loaded valve 24 translates against the force of the spring member 32, the fuel that is present in the spring chamber 18 flows into the horizontal bore 22 via the bore 28 that is defined in the solid portion 26. From within the horizontal bore 28, the fuel is channeled out of the high pressure fuel pump 10 via the bore 36 that is defined in the valve head 34 of the spring loaded valve 24. When the plunger 14 reaches its bottom dead center and

the pressure of the fuel in the spring chamber 18 decreases below the force required to translate the spring member 32, the spring member 32 causes the plug portion 30 of the spring loaded valve 24 to compress against the bore 28 that is defined on the solid portion 26, thereby preventing any further fuel from flowing from the spring chamber 18 into the horizontal bore 22. Moreover, the compression of the plug portion 30 of the spring loaded valve 24 prevents the lubrication oil from outside the high pressure fuel pump 10 from entering the spring chamber 18 via the bore 28 that is defined in the solid portion 26. Therefore, the spring loaded valve 24 prevents the flow of lubrication oil from an engine crankcase into the spring chamber 18 via the horizontal bore 22 that is defined in the housing 12 of the high pressure fuel pump 10.
[0010] 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.

We Claim
1. A high pressure fuel pump (10), said high pressure fuel pump (10) comprising:
a pump housing (12), said pump housing (12) comprising a barrel (16) defined
within said pump housing (12), and a plunger (14) positioned within said barrel
(16), said plunger (14) adapted to reciprocate within said barrel (16) and
deliver pressurized fuel from said high pressure fuel pump (10) to a fuel
injector;
a spring chamber (18) defined within said pump housing (12), said spring
chamber (18) adapted to house a spring (20) therein;
a horizontal bore (22) defined through a wall of said pump housing (12), a first
end of the horizontal bore (22) in flow communication with the spring chamber
(18) defined within said pump housing (12), an opposite second end of the
horizontal bore (22) in flow communication with an outer sidewall of said
pump housing (12); characterized in that
a spring loaded valve (24) positioned within said horizontal bore (22), said
spring loaded valve (24) adapted to channel a unidirectional flow of fuel from
the spring chamber (18) out of said high pressure fuel pump (10).
2. The high pressure fuel pump (10) in accordance with Claim 1 wherein an end
of said horizontal bore (22) comprises a solid portion (26) of said pump
housing extending within said horizontal bore (22), said solid portion (26) of
said pump housing (12) comprising a bore (28) defined there through, a first
end of the bore (28) in flow communication with the spring chamber (18), and
an opposite second end of the bore (28) in flow communication with the
horizontal bore (22).

3. The high pressure fuel pump (10) in accordance with Claim 2 wherein said spring loaded valve (24) comprises a plug portion (30) that is positioned against the bore (28) that is defined in said solid portion (26), a spring (32), a first end of said spring (32) positioned against said plug portion (30), an opposite second end of said spring (32) positioned against a valve head (34).
4. The high pressure fuel pump (10) in accordance with Claim 3 wherein said valve head (34) is inserted within the horizontal bore (32) to facilitate closing said horizontal bore (22), thereby preventing a flow of fuel from outside the high pressure fuel pump (10) into the spring chamber (18) via the horizontal bore (22).
5. The high pressure fuel pump (10) in accordance with Claim 3 wherein said valve head (34) comprises a bore (36) defined there through such that a first end of the bore (36) is in flow communication with the horizontal bore (22), an opposite second end of the bore (36) is in flow communication with a sidewall of said valve head (34) to facilitate channeling lubrication oil from the spring chamber (18) to the sidewall of said valve head (34) via the horizontal bore (22).