Gas engine.

摘要

The engine includes a pre-combustion chamber (12) in communication with a main combustion chamber (10), an intake passage (14) arranged to supply lean mixture to the main chamber (10), a gas pipe (18) to supply fuel gas to the pre-chamber (12) to form a rich mixture there, and a spark plug (20) to ignite the rich mixture in the pre-chamber (12) prior to combustion of the lean mixture in the main combustion chamber (10). To improve the mixing of fuel gas and air in the pre-chamber (12), at least a portion (42) of the pre-chamber (12) has a cross-sectional area which gradually decreases toward the main combustion chamber. Preferably the pre-chamber (12) inner surface (42) tapers gradually towards the main chamber (10) with the ratio of minimum and maximum diameters (d/D) being approximately 0.3.