Claims:1. A high pressure fuel pump (10), said high pressure fuel pump (10) comprising:
10 a housing (12);
a plunger (14) positioned within said housing (12), said plunger (14) adapted
to reciprocate within said housing (12);
a vertical groove (16) defined in said plunger (14), the vertical groove (16)
adapted to extend along a sidewall of said plunger (14); characterized in that
15 a helix groove (18) in flow communication with the vertical groove (16) and
extending angularly along a sidewall of said plunger (14), the helix groove (18)
having a variable depth that extends across a length of the helix groove (18).
2. The high pressure fuel pump (10) in accordance with Claim 1, wherein a depth
20 of the helix groove (18) is highest at an end of the helix groove (18) that is
adjoining the vertical groove (16) of said plunger (14), and wherein the depth
of the helix groove (18) is lowest at an end of the helix groove (18) that is
farthest away from the vertical groove (16) of said plunger (14).
3. The high pressure fuel pump (10) in accordance with Claim 2, wherein the
helix groove (18) comprises a linear tapering edge (22) of decreasing depth
that extends from the end of the helix groove (18) that is adjoining the vertical
groove (16) of said plunger (14) until the end of the helix groove (18) that is
farthest away from the vertical groove (16) of said plunger (14).
4. The high pressure fuel pump (10) in accordance with Claim 3, wherein the
linear tapering edge (22) of the helix groove (18) that extends from the end of
the helix groove (18) that is adjoining the vertical groove (5 16) of said plunger
(14) until the end of the helix groove (18) that is farthest away from the vertical
groove (16) of said plunger (14) has a constant tapering angle with reference
to a longitudinal axis of said plunger (14).
5. The high pressure fuel pump (10) in accordance with Claim 1, wherein a depth
of the helix groove (18) is highest at an end of the helix groove (18) that is
farthest away from the vertical groove (16) of said plunger (14), and wherein
the depth of the helix groove (18) is lowest at an end of the helix groove (18)
that is adjoining the vertical groove (16) of said plunger (14).
6. The high pressure fuel pump (10) in accordance with Claim 5, wherein the
helix groove (18) comprises a linear tapering edge (22) of decreasing depth
that extends from the end of the helix groove (18) that is farthest away from
the vertical groove (16) of said plunger (14) until the end of the helix groove
20 (18) that is adjoining the vertical groove (16) of said plunger (14).
7. The high pressure fuel pump (10) in accordance with Claim 6, wherein the
linear tapering edge (22) of the helix groove (18) that extends from the end of
the helix groove (18) that is farthest away from the vertical groove (16) of said
25 plunger (14) until the end of the helix groove (18) that is adjoining the vertical
groove (16) of said plunger (14) has a constant tapering angle with reference
to a longitudinal axis of said plunger (14). , Description:A high pressure fuel pump 10 is described. The high pressure fuel pump 10 comprises
a housing 12, and a plunger 14 positioned within the housing 12. A vertical groove 16
is defined in the plunger 14 and is adapted to extend along a sidewall of the plunger
10 14. A helix groove 18 is in flow communication with the vertical groove 16 and
extends angularly along a sidewall of the plunger 14. The helix groove 18 has a
variable depth that extends across a length of the helix groove 18. A depth of the helix
groove 18 is highest at an end of the helix groove 18 that is adjoining the vertical
groove 16 of the plunger 14, and wherein the depth of the helix groove 18 is lowest at
15 an end of the helix groove 18 that is farthest away from the vertical groove 16 of the
plunger 14.