| 摘要 |
PROBLEM TO BE SOLVED: To make normal operation off a surging zone possible with one supercharger in the whole operating area from the maximum output point of an engine to a low output area by providing a by-pass passage in such a way as to make a detour around an exhaust turbosupercharger, and controlling a flow control valve interposed in this by-pass passage according to the operating condition of the engine. SOLUTION: A by-pass passage 14 is provided to connect the outlet of an air cooler 7 in an air supply path 21 to an exhaust path 22 upstream of a turbine 3, and a flow control valve 13 is interposed in this by-pass passage 14. During the operation of an engine, a control device 15 inputting detection signals of an engine speed detector 24 and an air supply pressure detector 23 outputs an opening signal for the flow control valve 13 upon receiving such engine speed that an engine operating point is in a surging zone or such intake air pressure that the engine operating point is in a surging zone. Part of air supply cooled by the air cooler 7 is made to flow through the exhaust path 22 by the opening operation of the flow control valve 13 to increase the output of the turbine 3. |
