摘要 |
<p>The walls of the plunger (piston) of the fuel metering pump are relatively thin so that, when pressurized, they expand to provide more effective sealing. A plug is then used in the bore of the plunger to reduce its volume. In one embodiment the wall thickness in the portion of the plunger between the valving openings is further reduced to increase the wall expansion, and thus sealing, adjacent the valving openings. In some embodiments, ends of the members about the plunger are provided with skirts to decrease their tendency to expand, thus improving the sealing.</p> |