| 摘要 |
PROBLEM TO BE SOLVED: To prevent a part of oil from being abnormally heated after warming-up, in an internal combustion engine in which the oil is heated by heat of an exhaust gas at a low temperature of the engine.SOLUTION: A bypass oil feed passage 27 for heating is disposed in a main oil feed passage 19 having an oil pump 18, and a heating portion 27a receiving heat of an exhaust gas is formed in the bypass oil feed passage 27. A check valve 28 is disposed on a terminal end portion of the bypass oil feed passage 27, and a return passage 28 is connected to the bypass oil feed passage 27 at a slightly upstream side of the check valve 28. A flow rate adjustment valve 30 permitting natural flow-down of the oil and inhibiting pressure feed of the same, is disposed in the return passage 29. When the oil feed to the bypass oil feed passage 27 is stopped, all of the oil in the heating portion 27a and its periphery flows down into an oil pan 3, thus the oil is prevented from having an abnormally-high temperature. The same effect as that of the flow rate adjustment valve 30 can be achieved by thinning the return passage 29. |
