poppet-valve
Noun: - A type of valve: A "poppet-valve" is a valve that opens and closes by moving perpendicularly to its seat, typically used in internal combustion engines to control the flow of gases into and out of cylinders. It consists of a disk (the "poppet") that lifts off or settles onto a circular opening.
- (A specific valve component in an engine.)
- (A functional description of the valve's role.)
"Poppet-valve gear": The mechanism that controls the opening and closing of poppet-valves, often involving camshafts and springs.
- The camshaft lobe pushes the poppet-valve open against spring pressure. (A technical description of the valve's operation.)
"Poppet-valve timing": The precise scheduling of when a poppet-valve opens and closes relative to the engine's piston position.
- Adjusting poppet-valve timing can significantly affect engine performance. (A technical adjustment for optimization.)
Poppet (n): The disk-shaped part of the valve that seals the opening.
- The poppet must be ground to fit perfectly against its seat. (The disk component of the valve.)
Valve (n): A device that regulates the flow of a fluid (gas or liquid) by opening, closing, or partially obstructing passageways.
- The valve in the water pipe controls the flow. (General term for a flow-regulating device.)
- Mushroom valve: An older term for a poppet-valve, referring to its shape resembling a mushroom.
- Engine valve: A broader term that includes poppet-valves used in engines.
- (No common idioms directly involve "poppet-valve," as it is a technical term.)
- Poppet-valves are distinct from other valve types like slide valves or rotary valves, which move laterally or rotate instead of lifting vertically. They are standard in most reciprocating internal combustion engines (e.g., car, motorcycle, and small aircraft engines).