| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve weight reduction while ensuring rigidity of a cylinder head and a preferable cooling property of the cylinder head. <P>SOLUTION: The cylinder head of an internal combustion engine comprises a pair of supporting walls for supporting a cam shaft, an upper wall 67 for connecting the supporting walls while covering the cam shaft, four bolt inserting holes 81 formed surrounding the cam shaft from the upper wall 67 to the cam shaft side, and four bolt bosses 80 projecting from the upper wall 67 with the bolt inserting holes 81 opened so as to be fastened to a crank case by inserting a fastening bolt through the bolt inserting holes 81. A recess part 90 and a projection part 91 are formed on the outer surface of the upper wall 67. The boundary S1 between the recess part 90 and the projection part 91 is formed along two diagonal lines L1, L2 linking the bolt bosses 80. <P>COPYRIGHT: (C)2012,JPO&INPIT |
