instroke 排气行程
instroke[ noun ]
the stroke of an engine piston moving away from the crankshaft
<noun.event>
Instroke \In"stroke`\, n.
An inward stroke; specif., in a steam or other engine, a
stroke in which the piston is moving away from the crank
shaft; -- opposed to {outstroke}.
[Webster 1913 Suppl.]