| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve the simplification of structure and the upgrading of cooling performance when cooling lubricating oil at a point of a crank journal by using cooling water. <P>SOLUTION: An internal combustion engine has a cylinder block 1 and a crank shaft 7. An intermediate bearing recess 17 is formed in a region sandwiched by adjacent cylinder bores 4 in the cylinder block 1, and an intermediate bearing part for rotatably holding the intermediate crank journal 9 is constituted of the intermediate bearing recess 17 and an intermediate bearing cap 18. The lubricating oil is supplied to the intermediate bearing recess 17 from a lubricating oil supply hole 24. A main cooling water jacket 20 opened upwardly is formed at the cylinder block 1 so as to surround peripheries of the cylinder bores 4, and an auxiliary cooling water jacket 22 for cooling the intermediate bearing recess 17 is formed in a state that the main cooling water jacket 20 is downwardly extended. High cooling performance is exhibited by simple structure. <P>COPYRIGHT: (C)2013,JPO&INPIT |
