| 摘要 |
A valve open/close period control device that stably supports a torsion spring relative to an external position. The valve open/close period control device supports a spring holder, using a driven-side rotary body, and has a first engagement section to which a first arm of the torsion spring engages, formed in the spring holder. In addition, a spring holding section having a recessed shape in a circumferential area having a rotating shaft center as the center thereof is formed in an outer wall of a drive-side rotary body, in order to fit part of an inside end in a direction following the rotating shaft center in a coil section of the torsion spring. |
