| 摘要 |
PURPOSE:To facilitate machining work and obtain sufficient accuracy, by providing control valves in the vicinity of a cylinder so as to open and close the upper part of an opening of an exhaust passage and forming the control valves in a column shape to be slidably fitted to a cylindrical guide tube provided crossing with the exhaust passage. CONSTITUTION:A two-cycle cylinder 2, integrally forming in its side part an exhaust pipe 4 forming an exhaust passage 3 having an opening 3a in a cylinder internal surface 2a, provides an exhaust timing controller 5 in a connection part of the exhaust pipe 4 with the cylinder 2. This controller 5 is equipped with control valves 6, opening and closing an upper part of the opening 3a, and the valve 6, being slidably fitted into a cylindrical guide tube 7 provided crossing with the exhaust passage 3 in the vicinity of the upper part of the opening 3a, is controlled to be opened and closed by a driving mechanism 8. Further the control valve 6, corresponding to the guide tube 7, is formed in a column shape with the section in true roundness, while the control valve is constituted so that the valve, when it is closed, forms almost continuous control surfaces 6a in the cylinder internal surface 2a. |
