| 摘要 |
PURPOSE:To simplify bolt tightening work by forming integrally on a cylinder head, a boss part into which a sparkplug is threaded and fitting in said boss part, an attaching hole provided on the central portion of the head cover. CONSTITUTION:A sparkplug 14 is threaded into a boss part 12a in the central portion of a cylinder head 12. An attaching hole 16 provided through the central portion of a head cover 15 covering the cylinder head 12 is fitted in the boss part 12a, and further a nut 17 is threaded into the boss part 12a to closely fix said head cover 15 on the tip end of an outer wall 9. It is possible in such a way to subject the whole peripheral part of the head cover 15 to close uniformly contact with a cylinder block by tightening the central portion of the head cover 15 with one nut per one cylinder. Accordingly, the head cover 15 can be securely attached in a short period of time. |
