| 摘要 |
The engine has a piston (2) reciprocable within a cylinder (1) and provided with at least one piston ring (3) to ensure a close sliding fit within the cylinder (1). The uppermost piston ring (3) is so disposed as to define an annular space (4) above it and between the wall of the piston (2) and the cylinder wall (3). At least one inlet (5) is provided to said annular space (4), and means (7) are provided to supply fluid, such as air or harmless gas, to the inlet or inlets (5). The introduction of the air purges hydrocarbon gas from the space (4) and discourages its introduction into the space (4). Since hydrocarbon gas mixture in the space (4) is unlikely to be combusted fully, its exclusion from the space (4) improves the quality of the exhaust gases. <IMAGE> |
