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 (15) 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 (15) defined within said housing (12) to a fuel gallery (20) during an
15 end of a pumping stroke of said plunger (14);
a stop groove defined at an end of the helix groove (16), the stop groove
adapted to channel pressurized fuel from within the pumping chamber (15)
defined within said housing (12) to said fuel gallery (20) during stop condition
of said high pressure fuel pump (10), and wherein said plunger (14) is adapted
20 to be rotated to facilitate varying an orientation of the helix groove (16) and
the stop groove 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
a tapering circular groove (24) defined from an end of said plunger (14) that is
adjoining the pumping chamber (15) defined within said housing (12) and
extending along a longitudinal axis of said plunger (14), the tapering circular
groove (24) having a tapering shaped portion extending from an end of said
plunger (14) that is adjoining the pumping chamber defined within said
30 housing (12) to an outer circumference of said plunger (14), the tapering
circular groove (24) adapted to vary a delivery timing of pressurized fuel from
the pumping chamber (15) defined within said housing 5 (12) of said high
pressure fuel pump (10) to a fuel injector.
2. The high pressure fuel pump (10) in accordance with Claim 1 wherein said
tapering circular groove (24) has the smallest area of cross-section at the end
10 of said plunger (14) that is adjoining the pumping chamber defined within said
housing (12), and wherein the area of cross-section of said tapering circular
groove increases in a linearly tapering shaped profile, thereby extending from
the end of said plunger (14) that is adjoining the pumping chamber defined
within said housing (12) until it terminates at the outer circumference of said
15 plunger (14) along the longitudinal axis of said plunger (14).
3.The high pressure fuel pump (10) in accordance with Claim 1 wherein said
tapering circular groove (24) has the smallest area of cross-section at the end
of said plunger (14) that is adjoining the pumping chamber defined within said
20 housing (12), and wherein the area of cross-section of said tapering circular
groove increases in a parabolic tapering shaped profile, thereby extending from
the end of said plunger (14) that is adjoining the pumping chamber defined
within said housing (12) until it terminates at the outer circumference of said
plunger (14) along the longitudinal axis of said plunger (14).
4. The high pressure fuel pump (10) in accordance with Claim 3 wherein the area
of cross-section of said tapering circular groove increases in a convex parabolic
tapering shaped profile, thereby extending from the end of said plunger (14)
that is adjoining the pumping chamber defined within said housing (12) until
30 it terminates at the outer circumference of said plunger (14) along the
longitudinal axis of said plunger (14).
5. The high pressure fuel pump (10) in accordance with Claim 5 3 wherein the area
of cross-section of said tapering circular groove increases in a concave
parabolic tapering shaped profile, thereby extending from the end of said
plunger (14) that is adjoining the pumping chamber defined within said
housing (12) until it terminates at the outer circumference of said plunger (14)
10 along the longitudinal axis of said plunger (14).
6. The high pressure fuel pump (10) in accordance with Claim 1 wherein the
tapering circular groove (24) extends from the stop groove (18) defined at an
end of the helix groove (16) at its first end to an opposite end of the helix
15 groove (16) at its opposite second end and along an outer circumference of said
plunger (14).
7. The high pressure fuel pump (10) in accordance with Claim 1 wherein the
tapering circular groove (24) extends from the stop groove (18) defined at an
20 end of the helix groove (16) at its first end to an opposite end of the stop groove
(18) at its opposite second end and along an outer circumference of said
plunger (14).
8. The high pressure fuel pump (10) in accordance with Claim 1 wherein the
25 tapering circular groove (24) is of a non-uniform diameter as it extends along
a longitudinal axis of said plunger (14).
9. The high pressure fuel pump (10) in accordance with Claim 1 wherein an angle
of the taper extending from the end of said plunger (14) that is adjoining the
30 pumping chamber defined within said housing (12) to the outer circumference
of said plunger (14) is defined by a user.
10. The high pressure fuel pump (10) in accordance with Claim 5 1 wherein a length
of the tapering circular groove (24) along the horizontal axis of said plunger
(14) is defined by a user. , 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 within a pumping chamber 15
of housing 12. A helix groove 16 is defined on an outer circumference of the plunger
10 14. A tapering circular groove 24 is defined from an end of the plunger 14 that is
adjoining the pumping chamber 15 defined within housing 12 and extending along a
longitudinal axis of the plunger 14. The tapering circular groove 24 comprises a
tapering shaped portion extending from an end of the plunger 14 that is adjoining the
pumping chamber defined within the housing 12 to an outer circumference of the
15 plunger 14. The tapering circular groove 24 is adapted to vary a delivery timing of
pressurized fuel from the pumping chamber 15 of the high pressure fuel pump 10 to a
fuel injector.