Claims:We Claim:

1. A high pressure fuel pump, said high pressure fuel pump comprising:
a housing;
a valve body (10) coupled to said housing; characterized in that
a valve pin (12) positioned within said valve body (10), said valve pin (12) in sealing engagement with said valve body (10), the sealing engagement adapted to prevent fuel flow out of a pumping chamber of said high pressure fuel pump;
said valve pin (12) comprising a valve pin body (14) and an axial hole (16) defined within said valve pin body (14), said axial hole (16) adapted to channel fuel from said pumping chamber of said high pressure fuel pump; and
a radial hole (18) defined between the axial hole (16) and an outer portion of said valve pin body (14), said radial hole (18) adapted to channel fuel from the axial hole (16) out of said high pressure fuel pump.

2. The high pressure fuel pump in accordance with Claim 1 further comprising a valve pin cone (20) defined proximate an end portion of said valve pin (12), said valve pin cone (20) adapted to facilitate sealing said valve pin (12) against said valve body (10).

3. The high pressure fuel pump in accordance with Claim 2 further comprising a circumferential seal (22) defined proximate said valve pin cone (20) and adjacent said radial hole (18), the radial hole (18) disposed between the circumferential seal (22) and said valve pin cone (20), said circumferential seal (22) facilitating sealing engagement and adapted to prevent fuel flow out of said pumping chamber of said high pressure fuel pump when fuel is being channeled out of said radial hole (18).

4. A high pressure fuel pump, said high pressure fuel pump comprising:
a housing;
a valve body (10) coupled to said housing;
a valve pin (12) positioned within said valve body (10);
a valve pin cone (20) defined proximate an end portion of said valve pin (12), said valve pin cone (20) facilitates sealing said valve pin (12) against said valve body (10); characterized in that
said valve pin (12) comprising a circumferential seal (22) defined proximate said valve pin cone (20), said valve pin (12) comprising a recess (23) defined between said circumferential seal (22) and said valve body (10) to permit a flow of fuel past said circumferential seal (22) and out of said high pressure fuel pump.

5. A valve pin (12) positioned within a valve body (10), said valve pin (12) in sealing engagement with said valve body (10), the sealing engagement adapted to prevent fuel flow out of a pumping chamber of said high pressure fuel pump, said valve pin (12) comprising:
a valve pin body (14) and an axial hole (16) defined within said valve pin body (14), said axial hole (16) adapted to channel fuel from said pumping chamber of said high pressure fuel pump; and
a radial hole (18) defined between the axial hole (16) and an outer portion of said valve pin body (14), said radial hole (18) adapted to channel fuel from the axial hole (16) out of said high pressure fuel pump.

6. The valve pin (12) in accordance with Claim 5 further comprising a valve pin cone (20) defined proximate an end portion of said valve pin (12), said valve pin cone (20) adapted to facilitate sealing said valve pin (12) against said valve body (10).

7. The valve pin (12) in accordance with Claim 6 further comprising a circumferential seal (22) defined proximate said valve pin cone (20) and adjacent said radial hole (18), the radial hole (18) disposed between the circumferential seal (22) and said valve pin cone (20), said circumferential seal (22) facilitating said sealing engagement and adapted to prevent fuel flow out of said pumping chamber of said high pressure fuel pump when fuel is being channeled out of said radial hole (18).
8. A valve pin (12) for permitting fuel flow through a high pressure fuel pump said valve pin (12) comprising:
a valve pin cone (20) defined proximate an end portion of said valve pin (12), said valve pin cone (20) facilitates sealing said valve pin (12) against a valve body (10); characterized in that
said valve pin (12) comprising a circumferential seal (22) defined proximate said valve pin cone (20), said valve pin (12) comprising a recess (23) defined between said circumferential seal (22) and said valve body (10) to permit a flow of fuel past said circumferential seal (22) and out of said high pressure fuel pump.
, Description:Field of the invention
[0001] This invention relates to a valve pin and more particularly to a valve pin for a high pressure fuel pump.

Background of the invention
[0002] IN 06550CH2014 A describes a fuel injection pump. The fuel injection pump comprises a pump housing having a delivery end and a pressurizing end, a pumping chamber, and a delivery valve holder. The pump is characterized in having a valve holder, a valve pin, and a valve body. The valve holder is located in the pumping chamber, and has a central inlet hole to accommodate the valve pin, and multiple outlet holes. The valve body has at least one inlet path opening into a hole and multiple outlet paths. The valve holder and the valve body are in aligned engagement with each other in a manner such that the hole of the valve body is in fluid communication with the central inlet hole and at least one outlet path in fluid communication with at least one outlet hole.

Brief description of the accompanying drawings
[0003] Figure 1 illustrates a schematic diagram of a valve pin of a high pressure fuel pump in one embodiment of the invention.
[0004] Figure 2 illustrates a schematic diagram of the valve pin of the high pressure fuel pump in another embodiment of the invention.

Detailed description of the invention
[0005] A high pressure fuel pump is described. The high pressure fuel pump comprises a housing and a valve body 10 coupled to the housing. A valve pin 12 is positioned within the valve body 10, the valve pin 12 in sealing engagement with the valve body 10, the sealing engagement adapted to prevent fuel flow out of a pumping chamber of the high pressure fuel pump. The valve pin 12 comprises a valve pin body 14 and an axial hole 16 defined within the valve pin body 14, the axial hole 16 adapted to channel fuel from the pumping chamber of the high pressure fuel pump. A radial hole 18 is defined between the axial hole 16 and an outer portion of the valve pin body 14, the radial hole 18 adapted to channel fuel from the axial hole 16 out of the high pressure fuel pump.

[0006] Another embodiment of a high pressure fuel pump and a valve pin is described. The high pressure fuel pump comprises a housing and a valve body 10 coupled to the housing. A valve pin 12 is positioned within the valve body 10. A valve pin cone 20 is defined proximate an end portion of the valve pin 12, the valve pin cone 20 facilitates sealing the valve pin 12 against the valve body 10. The valve pin 12 comprises a circumferential seal 22 defined proximate the valve pin cone 20, the valve pin 12 comprising a recess 23 defined between the circumferential seal 22 and the valve body 10 to permit a flow of fuel past the circumferential seal 22 and out of the high pressure fuel pump.

[0007] A valve pin 12 is positioned within a valve body 10, the valve pin 12 in sealing engagement with the valve body 10, the sealing engagement adapted to prevent fuel flow out of a pumping chamber of the high pressure fuel pump. The valve pin 12 comprises a valve pin body 14 and an axial hole 16 defined within the valve pin body 14. The axial hole 16 is adapted to channel fuel from the pumping chamber of the high pressure fuel pump. A radial hole 18 is defined between the axial hole 16 and an outer portion of the valve pin body 14, the radial hole 18 adapted to channel fuel from the axial hole 16 out of the high pressure fuel pump.

[0008] A valve pin 12 for permitting fuel flow through a high pressure fuel pump is described. The valve pin 12 comprises a valve pin cone 20 defined proximate an end portion of the valve pin 12, the valve pin cone 20 facilitates sealing the valve pin 12 against a valve body 10. The valve pin 12 comprises a circumferential seal 22 defined proximate the valve pin cone 20, the valve pin 12 comprising a recess 23 defined between the circumferential seal 22 and the valve body 10 to permit a flow of fuel past the circumferential seal 22 and out of the high pressure fuel pump. The circumferential seal 22 causes partial sealing engagement between the circumferential seal 22 and the valve body 10, thus allowing only a portion of the fuel to flow past the circumferential seal 22 and out of the high pressure fuel pump.
[0009] Figure 1 illustrates a schematic diagram of a valve pin 12. The valve pin 12 comprises a valve pin body 14. A valve pin cone 20 comprises a circumferential conically shaped portion that is in sealing contact against a valve body 10. The valve pin cone 20 facilitates channeling fuel from a pumping chamber of the high pressure fuel pump when the valve pin 12 is lifted due to pressurized fuel acting on the valve pin 12. A circumferential seal 22 is coupled to the valve pin 12. The circumferential seal 22 prevents fuel from the pumping chamber from flowing past the circumferential seal 22 and out of the high pressure fuel pump. In an alternate exemplary embodiment, a projection may be coupled to the valve pin body 14 and prevents fuel flow out of the high pressure fuel pump. In yet another alternate exemplary embodiment, any other suitable means may be coupled to the valve pin body 14 that prevents fuel flow out of the high pressure fuel pump.

[0010] An axial hole 16 is defined in the valve pin body 14. The axial hole 16 is adapted to channel fuel from the pumping chamber of the high pressure fuel pump. A radial hole 18 is defined between the axial hole 16 and an outer portion of the valve pin body 14. The radial hole 18 is adapted to channel fuel from the axial hole 16 out of the high pressure fuel pump. More specifically, when the valve pin cone 20 is lifted due to pressurized fuel acting on the valve pin body 14, pressurized fuel flows through the axial hole 16 and is channeled to the radial hole 18. From the radial hole 18, the pressurized fuel is channeled via the valve pin cone 20 to a fuel injector. The flow of fuel from the radial hole 18 to the fuel injector causes pilot fuel injection in the fuel injector of the engine.

[0011] A working of the valve pin 12 is described as an example. Pressurized fuel flows from the pumping chamber of the high pressure fuel pump to the axial hole 16 and through the radial hole 18. Due to the pressurized nature of the fuel, the valve pin cone 20 is lifted upwardly. Pressurized fuel flows through the radial hole 18 and out of the high pressure fuel pump past the valve pin cone 20. This phenomenon causes pilot injection in the fuel injector. As the valve pin 12 continues to lift upwardly, the circumferential seal 22 is lifted upwardly past the valve body 10. The translation of the circumferential seal 22 past the valve body 10 causes pressurized fuel to flow through the space defined between the valve body 10 and the valve pin body 14 and out of the high pressure fuel pump. The flow of pressurized fuel through the space defined between the valve body 10 and the valve pin body 14 causes the main injection event in the fuel injector.

[0012] Figure 2 illustrates a schematic diagram of the valve pin 12 in another embodiment of the invention. The valve pin 12 comprises a valve pin body 14 that is inserted within the valve body 10. A valve pin cone 20 comprises a circumferential conically shaped portion that is in sealing contact against the valve body 10. The valve pin cone 20 facilitates channeling fuel from the pumping chamber of the high pressure fuel pump when the valve pin 12 is lifted due to pressurized fuel acting on the valve pin 12. A circumferential seal 22 is coupled to the valve pin 12. The circumferential seal 22 comprises a recess 23 that is defined between the circumferential seal 22 and the valve body 10, when the valve pin 12 is inserted into the valve body 10. The recess 23 that is defined between the circumferential seal 22 and the valve body 10 permits a controlled quantity of fuel from the pumping chamber of the high pressure fuel pump as will be explained in detail below. The controlled quantity of fuel that is channeled from the pumping chamber of the high pressure fuel pump is supplied to the fuel injector of the engine and injected thereafter.

[0013] A working of the valve pin 12 illustrated in Figure 2 is described as an example. Pressurized fuel flows from the pumping chamber of the high pressure fuel pump to the circumferential seal 22. A controlled quantity of the pressurized fuel flows through the recess 23 that is that is defined between the circumferential seal 22 and the valve body 10. Due to the pressurized nature of the fuel, the valve pin cone 20 is lifted upwardly. The controlled quantity of the pressurized fuel flows through the recess 23 that is defined between the circumferential seal 22 and the valve body 10 and out of the high pressure fuel pump past the valve pin cone 20. This phenomenon causes pilot injection in the fuel injector. As the valve pin 12 continues to lift upwardly, the circumferential seal 22 is lifted upwardly past the valve body 10. The translation of the circumferential seal 22 past the valve body 10 causes pressurized fuel to flow through the space defined between the valve body 10 and the circumferential seal 22 and out of the high pressure fuel pump. The flow of pressurized fuel through the space defined between the valve body 10 and the valve pin body 14 causes the main injection event in the fuel injector. The advantage of the valve pin 12 is that the pilot fuel injection can be achieved by means of the high pressure fuel pump rather than being achieved by means of the fuel injector.

[0014] 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 leverage and dimensions of various components are envisaged and form a part of this invention. The scope of the invention is only limited by the claims.