| 摘要 |
To provide an inner shim that is unlikely to fall off from a spring retainer even when an anomalous operation of valve occurs. A spring retainer fixed to the upper end portion of a valve shaft has a shim-attachment hole. While the upper end portion of the valve shaft serves as the base face of the shim- attachment hole, the hole has an open end on the upper side. An inner shim i s fitted into the shim-attachment hole. The bottom face of the inner shim is i n contact with the upper end portion of the valve shaft, and the top face of t he inner shim is positioned below the upper edge of the shim-attachment hole. A tappet is disposed above the spring retainer, and is allowed to move freely in the axial direction of the valve shaft. A shim-holding projection sticks out from the under face of the tappet, and extends downward. The projection enters, from above, the inside of the shim-attachment hole, and is in contac t with the top face of the inner shim. |
