| 摘要 |
PROBLEM TO BE SOLVED: To prevent positively various malfunctions caused by excessive high temperature of a cylinder by increasing a cooling effect of the cylinder and realize a further high output of an engine.SOLUTION: Vertical cooling fins 5g arranged in parallel in respect a cylinder axis line 5a are arranged between a muffler 6 and a cylinder outer wall 5d of a cylinder 5 provided with a plurality of horizontal cooling fins 5f extended in a direction crossing at a right angle with the cylinder axis line 5a along a reciprocating direction of a piston 5c at an outer periphery, a surface area of the cooling fin itself is increased to perform a cooling of the cylinder in an efficient manner, the muffler 6 where exhaust gas is discharged is prevented from being increased and the temperature of the cylinder outer wall 5d of the cylinder 5 around the muffler 6 is restricted from being increased to a high temperature. |
