| 摘要 |
<p>PURPOSE:To prevent any creation of a surface damage, broken damage and so forth of a piston rod using SF60 or S45C according to JIS as the material thereof by tempering the rod after the treatment of high frequency quanching so as to have the surface hardness of Hv400-450 at the sliding part thereof. CONSTITUTION:The piston rod 6 of internal-combustion engine, made of SF60 or S45C according to JIS, is subjected to the high frequency quenching and then tempering to obtain the surface hardness of Hv400-450. By adopting the treatment of the high frequency quenching, the quenched part of the piston rod 6 can be within the part having a little larger than that of the sliding part thereof an in addition, the need of the polishing work or the like for the sliding part after the tempering work may be eliminated. The sliding part of the piston rod 6 after it is tempered has the surface hardness as high as Hv400-450. Because of the reason, any evidence of scratch on the piston rod sliding face created when hard substances bite the face may be prevented if the piston rod 6 is used in combination with a cast iron scraper ring and a seal ring 8 which are made of cast iron.</p> |
