Claims:1. A high pressure fuel pump (10), said high pressure fuel pump (10) comprising:
10 a housing (12), and a plunger (14) adapted to reciprocate within a pumping
chamber defined within said housing (12);
a helix groove (16) defined on an outer circumference of said plunger (14), the
helix groove (16) adapted to channel pressurized fuel from within the pumping
chamber defined within said housing (12) to a fuel gallery (18) during an end
15 of a pumping stroke of said plunger (14);
a stop groove (20) defined at an end of the helix groove (16), the stop groove
(20) adapted to channel pressurized fuel from within the pumping chamber
defined within said housing (12) to said fuel gallery (18) during a stop
condition of said high pressure fuel pump (10), and wherein said plunger (14)
20 is adapted to be rotated to facilitate varying an orientation of the helix groove
(16) and the stop groove (20) for different loading conditions of said high
pressure fuel pump (10);
a barrel (22) positioned between said plunger (14) and said housing (12);
characterized in that
25 a circular groove (24) defined at an end of said plunger (14) that is proximate
to the pumping chamber and extending from a stop groove 20 along a
circumference of said plunger (14), wherein an outer diameter (26) of said
circular groove (24) is coaxial with reference to a circular contour profile of an
inner diameter (28) of said circular groove (24), the circular groove (24)
30 adapted to vary a delivery timing of pressurized fuel from the pumping
chamber defined within said housing (12) of said high pressure fuel pump (10)
to a fuel injector.
2. The high pressure fuel pump (10) in accordance with Claim 5 1 wherein the
circular groove (24) is formed by grinding the circular groove (24) from the
stop groove (20) and along the circumference of said plunger (14) until the
culmination of the circular groove (24).
3. The high pressure fuel pump (10) in accordance with Claim 2 wherein a bottom
surface of the circular groove (24) of said plunger (14) has a smooth surface
finish due to grinding the circular groove (24) from the stop groove (20) and
along the circumference of said plunger (14) until the culmination of the
circular groove (24).
4. The high pressure fuel pump (10) in accordance with Claim 1 wherein a length
of the circular groove (24) extending along the circumference of said plunger
(14) extends from the stop groove (20) and partially around the circumference
of said plunger (14).
20
5. The high pressure fuel pump (10) in accordance with Claim 1 wherein a length
of the circular groove (24) extending along the circumference of said plunger
(14) extends from the stop groove (20) at one end and completely around the
circumference of said plunger (14) until the opposite end of the stop groove
(20).
6. The high pressure fuel pump (10) in accordance with Claim 1 wherein the outer
diameter (26) of the circular groove (24) is defined at a predetermined positive
displacement from an end of said plunger (14) that is proximate to the pumping
30 chamber defined within said housing (12) 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 14 adapted to reciprocate therein. A helix groove 16 is
defined on an outer circumference of the plunger 14. A stop groove 20 is defined at an
10 end of the helix groove 16. The plunger 14 is adapted to be rotated to facilitate varying
an orientation of the helix groove 16. A circular groove 24 is defined at an end of the
plunger 14 that is proximate to the pumping chamber and extending from a stop groove
20 along a circumference of the plunger 14. An outer diameter 26 of the circular
groove 24 is coaxial with reference an inner diameter 28 of the circular groove 24. The
15 circular groove 24 is adapted to vary a delivery timing of pressurized fuel from the
high pressure fuel pump 10.