| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an air scavenging type two cycle engine having scavenging ports which are easily machined, hardly increase the resistance of a piston, and hardly cause blow-by in scavenging, and its manufacturing method. <P>SOLUTION: This cylinder is provided with the scavenging ports 13a, 14a formed in the inner surface of a cylinder 1, opened obliquely upward with respect to a cylinder axis center C, and communicated with a combustion chamber 1a. The scavenging ports 13a, 14a are formed by cutting from the side of the inner surface of the cylinder 1 by rotating, around an axis center K, a rotary cutting tool 62 having an inclined surface 62b which is formed on the peripheral part of the upper surface of the rotary cutting tool and is inclined downward toward the outward in a radial direction. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
