| 摘要 |
PROBLEM TO BE SOLVED: To keep a high output in any of low, medium and high engine rotations by providing a partitioning part for dividing an opening part into a plurality of pieces in the cylinder internal opening part of the exhaust passage of a 2-cycle engine, and protruding and retreating an integrated type valve member having the fitting structure to the partitioning part to/from the exhaust passage. SOLUTION: In the cylinder internal opening of an exhaust passage 3 in a 2-cycle engine 100a to be loaded on a snow mobile or the like, a rib 2 vertical to the horizontal plane of a cylinder 4 for halving the opening is provided as a partitioning part. A valve 6 protruded and retreated through a wire 12 to regulate the opening of the exhaust passage 3 is formed so as to have a tip part 8 having a recessed form fitted to the curved surface of the cylinder and a groove 7 for fitting the rib 2 in the center part. According to this, the resistance to high heat of the valve 6 is enhanced to eliminate the increase in moving friction resistance by the increase in thermal distortion of the valve itself, so that the output of the engine can be smoothly increased.
|
