PURPOSE: To improve the efficiency of an engine through the reduction of the load of an oil feed device, by controlling an oil feed flow regulation mechanism for the supercharger oil feed device on the basis of an engine revolution number and an intaken air amount, and reducing an oil feed amount at the time of a low speed low load operation especially.

CONSTITUTION: Exhaust gas discharged from an engine 1 is introduced to a turbine 2, and an impeller 3 formed at one end of a shaft 4 is made to rotate. Meanwhile, air intaken from an air cleaner 6 is introduced to a compressor 8 through an air flow meter 7, and compression is made by means of an impeller 9 formed at the other end of the shaft 4. Also, oil within a pan 11 is sucked by means of a pump 10 driven by the engine 1, and supplied to the bearing portion 5 of the shaft 4 through a passage 16. In this instance, respective detection signals from the air flow meter 7 and an engine revolution number sensor 13 are respectively inputted into a control unit 14. And the pump 10 is controlled through a control means 15 by means of an output from the control unit 14.