| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To ensure a slide property of a valve stem by avoiding a burr generated at the periphery of an opening of a stem hole from being pressed by a guide pin and directed to the stem hole side during forming. <P>SOLUTION: A stem hole 17b of a valve storing hole 17 axially penetrated and formed from an end surface of a tip end side shaft part 14 to a guide hole 16 radially penetrated and formed on an intermediate shaft part 13 of a piston is formed by a core 24 for a valve storing hole having a tip end projecting to the guide hole 16. A recessed groove 18 having a narrower width than a diameter of the guide pin 5 is formed on a side wall of the stem hole of the guide hole 16. <P>COPYRIGHT: (C)2004,JPO</p> |
