| 摘要 |
PURPOSE: A piston cooling system of an internal combustion engine is provided to improve fuel efficiency and to reduce exhaust gas by stopping cooling a piston at a low temperature. CONSTITUTION: An oil pump(2) pumps and delivers the engine oil collected in a crank case(4), and the oil is filtered by a filter(6) and supplied to respective frictional parts via a main oil gallery(8) and to an oil jet(10). The oil jet jets the oil to the lower portion of a piston(12). Then, the piston is cooled by the oil. An electrical switch member(16) is placed in an inlet of an oil jet passage(14), and an ECU(Electronic Control Unit) controls the switch member according to the data inputted from a cooling water temperature sensor(18) and an RPM(Revolutions Per Minute) sensor(20). If engine RPM is less than an idle level, the ECU forwardly moves an actuator rod via a solenoid. Then, the actuator rod contacts to a valve body with the compression of first and second springs and the front end face of the valve body closes a first through hole to cut off the supply of oil to the oil jet passage from the oil gallery.
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