PRECOMBUSTION CHAMBER TYPE GAS ENGINE

摘要

PROBLEM TO BE SOLVED: To provide a precombustion chamber type gas engine where combustion stability of an engine is enhanced by increasing flow velocity of combustion flame injected from an injection hole so as to sufficiently combust lean mixture air inside a main combustion chamber.SOLUTION: A precombustion chamber type gas engine 1 includes a precombustion chamber 10 and a main combustion chamber 20 that are in communication with each other through an injection hole 14 disposed on a precombustion chamber cap 12. Combustion flame generated in the precombustion chamber 10 is injected into the main combustion chamber 20 through the injection hole 14 so as to combust mixed air inside the main combustion chamber 20. The injection hole 14 has a diameter that decreases gradually from an inlet 14a into which the combustion flame flows toward a throat portion 14b having an opening diameter that is smaller than an opening diameter of the inlet 14a, and has a Laval nozzle shape whose diameter gradually increases from the throat portion 14b toward an outlet 14c from which the combustion flame flows out.