| 摘要 |
<p>A fuel pump (10) for supplying fuel to an internal combustion engine employs at least one composite pumping plunger (43) disposed within a plunger bore (46) for reciprocation therein. Each composite plunger comprises at least a high-pressure plunger element (48), which is in contact with a high-pressure fuel charge to be delivered by the pump, and an abutting leak-off plunger element (47) disposed between the high-pressure element and a plunger actuating member (50, 52). The plunger elements of each composite plunger are stacked in the direction of reciprocation such that the abutting plunger elements form confronting end faces. The confronting end face of at least one of the elements in each composite plunger is contoured and the confronting end face of the abutting element is non-complementary in shape. This arrangement of confronting faces of abutting plunger elements causes the composite plungers to freely reciprocate within the plunger bores in self-centering fashion and provides a tighter seal at the interfaces of the composite plungers and the plunger bores.</p> |
