Claims:1. A high pressure fuel pump (10), said high pressure fuel pump (10) comprising:
10 a housing (12), and a plunger adapted to reciprocate within a pumping chamber
defined within said housing (12) and deliver pressurized fuel to a fuel injector;
a delivery valve assembly (14) in flow communication with the pumping
chamber and adapted to control a quantity of pressurized fuel that is delivered
from the pumping chamber defined within said housing (12) to said fuel
15 injector, said delivery valve assembly (14) comprising:
a delivery valve body (16), and a bore (18) extending from a first end
of said delivery valve body (16) to an opposite second end of said
delivery valve body (16);
a delivery valve pin (20) positioned within the bore (18) of said delivery
20 valve body (16), said delivery valve pin (20) adapted to translate
upwardly due to a force of the pressurized fuel to facilitate channeling
pressurized fuel from within the pumping chamber defined within said
housing (12) to said fuel injector via the bore (18) of said delivery valve
body (16); characterized in that
25 an annular groove (22) extending from an upper end of said delivery
valve body (16) to a portion along a longitudinal axis of said delivery
valve body (16), a film of fuel maintained within the annular groove
(22) and between said delivery valve body (16) and said delivery valve
pin (20) to facilitate advancing a fuel delivery timing of pressurized
30 fuel from the pumping chamber to said fuel injector at lower pumping
speeds of said high pressure fuel pump (10).
2. The high pressure fuel pump (10) in accordance with Claim 5 1, wherein the
annular groove (22) extends from a sidewall of the bore (18) of said delivery
valve body (16) to a portion perpendicular to the longitudinal axis of said
delivery valve body (16), wherein the depth of the annular groove (22) that
extends from the sidewall of the bore (18) of said delivery valve body (16) to
10 the portion perpendicular to the longitudinal axis of said delivery valve body
(16) is user defined.
3. The high pressure fuel pump (10) in accordance with Claim 2, wherein the
depth of the annular groove (22) that extends from the sidewall of the bore of
15 said delivery valve body (16) to the portion perpendicular to the longitudinal
axis of said delivery valve body (16) is user defined to facilitate maintaining a
film of fuel within the annular groove (22) and between said delivery valve
body (16) and said delivery valve pin (20).
4. The high pressure fuel pump (10) in accordance with Claim 1, wherein the film
of fuel maintained within the annular groove (22) and between said delivery
valve body (16) and said delivery valve pin (20) collapses when the pumping
speed of said high pressure fuel pump (10) decreases below a threshold
pumping speed, thereby advancing a fuel delivery timing of pressurized fuel
25 from the pumping chamber to said fuel injector of said high pressure fuel pump
(10).
5.The high pressure fuel pump (10) in accordance with Claim 1, wherein the film
of fuel maintained within the annular groove (22) and between said delivery
30 valve body (16) and said delivery valve pin (20) is sustained when the pumping
speed of said high pressure fuel pump (10) increases above a threshold
pumping speed, thereby maintaining a normal fuel delivery timing of
pressurized fuel from the pumping chamber to said fuel injector 5 of said high
pressure fuel pump (10). , Description:A high pressure fuel pump 10 is described. The high pressure fuel pump 10 comprises
a housing 12, and a plunger adapted to reciprocate within the housing 12. A delivery
valve assembly 14 is in flow communication with the pumping chamber. The delivery
10 valve assembly 14 comprises a delivery valve body 16, and a bore 18 extending there
through. A delivery valve pin 20 is positioned within the bore 18 of the delivery valve
body 16. An annular groove 22 extends from an upper end of the delivery valve body
16 to a portion along its longitudinal axis, a film of fuel maintained within the annular
groove 22 and between the delivery valve body 16 and the delivery valve pin 20 to
15 facilitate advancing a fuel delivery timing of pressurized fuel from the pumping
chamber at lower pumping speeds of the high pressure fuel pump 10.