| 摘要 |
An internal combustion engine E is configured such that a cylinder block 2 and a cylinder head 3, in which a valve operation mechanism receiving chamber 32 for receiving a valve operation mechanism 80 is formed by the outer peripheral wall 30 of the cylinder head 3, are sequentially stacked on a crankcase 1, and the crankcase 1, the cylinder block 2, and the cylinder head 3 are fastened together by a plurality of stud bolts 70 and a plurality of fastening members 71, the plurality of stud bolts 70 and the plurality of fastening members 71 being arranged surrounding a cylinder bore 21 in the circumferential direction when viewed in the direction of the center axis C1 of the cylinder. The cylinder head 3 has formed thereon a plurality of bolt mounting boss sections 50 through which the stud bolts 70 pass respectively, the plurality of bolt mounting boss sections 50 consisting of inner bolt mounting boss sections 51 disposed inside the valve operation mechanism receiving chamber 32 in the cylinder head 3, the plurality of bolt mounting boss sections 50 further consisting of outer bolt mounting boss sections 55 disposed outside the valve operation mechanism receiving chamber 32. When viewed in the direction of the center axis C1 of the cylinder, portions of the outer peripheral wall 30 of the cylinder head 3 are recessed inward to form recesses 35 so that the outer peripheral wall 30 does not interfere with seat surfaces 56a, 57a for the fastening members 71, the seat surfaces 56a, 57a being located on the outer bolt mounting boss sections 55. The provided internal combustion engine can be maintained easily, is compact, and is lightweight. |
