| 摘要 |
PURPOSE:To prevent a mixture from leaking while a residual pressure wave from being damped, by arranging an exhaust hole and a scavenge hole, opened and closed by a piston, in a specific position while fitting a piston pin, closing its end part, into a supporting hole on a side wall of the piston. CONSTITUTION:An engine 1 parallelly arranges in the lengthwise direction of a crank 2 with a distance apart two sets of connecting rods 3 turnably supported to the crank 2, pistons 5 provided to be lined in this connecting rod 3 through a piston pin 4 and cylinders 8 having an exhaust hole 6a and a scavenge hole 7a opened and closed by the piston 5. Here the exhaust hole 6a and the scavenge hole 7a are provided in a position that they are spaced in the peripheral direction of the cylinder 8 further overlapped with end surfaces 4a, 4b of the piston pin 4 on their extension line in accordance with a movement of the piston 5. While the piston pin 4 fits its each end part 4a, 4b into a supporting hole 5a, concentrically formed in a side wall of the piston 5, and closes at least one end part 4a. |
