Claims:1. A high pressure fuel pump (10), said high pressure fuel pump (10) comprising:
10 a barrel (12), said barrel (12) comprising a barrel body (13) and a spill port
(15) defined through said barrel body (13) that is perpendicular to a
longitudinal axis of said barrel body (13);
a plunger (14) positioned within said barrel (12) and adapted to reciprocate
within said barrel (12) from a bottom dead center position to a top dead center
15 position, said plunger (14) comprising:
a cylindrical portion (16); characterized in that
a T and inverted T-shaped groove (18) defined on an outer sidewall of
said plunger (14), the T and inverted T-shaped groove (18) adapted to
recirculate pressurized residual fuel to a fuel gallery of said high
20 pressure fuel pump (10) via the spill port (15) defined through said
barrel body (13).
2. The high pressure fuel pump (10) in accordance with Claim 1, wherein the T
and inverted T-shaped groove (18) comprises a first T-shaped groove (20)
25 defined on said plunger (14) and positioned along a longitudinal axis of said
plunger (14), and a second inverted T-shaped groove (22) defined on said
plunger (14) and positioned along the longitudinal axis of said plunger (14).
3. The high pressure fuel pump (10) in accordance with Claim 2, wherein a
30 horizontal portion (24) of the first T-shaped groove (20) defined on said
plunger (14) is in flow communication with a stem portion (26) of the second
inverted T-shaped groove (22) defined on said plunger (14) 5 to define a first
node (35).
4. The high pressure fuel pump (10) in accordance with Claim 3, wherein a
horizontal portion (28) of the second inverted T-shaped groove (22) defined on
10 said plunger (14) is in flow communication with a stem portion (30) of the first
T-shaped groove (20) defined on said plunger (14) to define a second node
(37).
5. The high pressure fuel pump (10) in accordance with Claim 4, wherein a third
15 node (39) is defined at a point of contact between the stem portion (30) of the
first T-shaped groove (20) and the horizontal portion (24) of the first T-shaped
groove (20).
6. The high pressure fuel pump (10) in accordance with Claim 5, wherein a fourth
20 node (41) is defined at a point of contact between the stem portion (26) of the
second inverted T-shaped groove (22) and the horizontal portion (28) of the
second inverted T-shaped groove (22).
7. The high pressure fuel pump (10) in accordance with Claim 6, wherein
25 pressurized fuel from the stem portion (30) of the first T-shaped groove (20),
the stem portion (26) of the second inverted T-shaped groove (22), the
horizontal portion (24) of the first T-shaped groove (20), and the horizontal
portion (28) of the second inverted T-shaped groove (22) are collected within
the first node (35), the second node (37), the third node (39), and the fourth
30 node (41) respectively.
8. The high pressure fuel pump (10) in accordance with 5 Claim 7, wherein
pressurized fuel that is collected within the first node (35), the second node
(37), the third node (39), and the fourth node (41) respectively flow into a fuel
gallery of the high pressure fuel pump (10) when the spill port (15) defined
through said barrel body (13) is in flow communication with each of said first
10 node (35), said second node (37), said third node (39), and said fourth node
(41), during a rotation of said plunger (14) and a translation of said plunger
(14) from a bottom dead center position to a top dead center position of said
high pressure fuel pump (10). , Description:A high pressure fuel pump 10 is described. The high pressure fuel pump 10 comprises
a barrel 12, the barrel 12 comprising a barrel body 13 and a spill port 15 defined
through the barrel body 13 that is perpendicular to a longitudinal axis of the barrel
10 body 13. A plunger 14 is positioned within the barrel 12 and is adapted to reciprocate
within the barrel 12 from a bottom dead center position to a top dead center position.
The plunger 14 comprises a cylindrical portion 16. A T and inverted T-shaped groove
18 is defined on an outer sidewall of the plunger 14. The T and inverted T-shaped
groove 18 is adapted to recirculate pressurized residual fuel to a fuel gallery of the
15 high pressure fuel pump 10 via the spill port 15 that is defined through the barrel body
13.