The piston moves up and down in the piston chamber primarily in response to changes in intake manifoldvacuum.
活塞主要因进气歧管真空度的变化而在活塞腔内上下移动。
2
When the engine is shut off, the intake manifold cools and a slight vacuum forms as a result .
这是因为当发动机熄火时,进气歧管冷却而产生轻微的真空。
3
A downstream vacuum relief (48) on the vacuummanifold functions to discharge particulate material from the pockets into the cavities at a predetermined discharge location on the wheel.