| 摘要 |
PROBLEM TO BE SOLVED: To prevent the loss of suction and exhaust and the degradation of fuel consumption in a running region of gas flow rate exceeding a predetermined valve by connecting two turbines to a turbo coaxially with a compressor while making exhaust paths separatively formed into two systems communicate to each other through a communicating passage having a valve interposed therein. SOLUTION: During running of an engine, the detecting signals of a rotation sensor and load sensor are read in a controller 16 to judge whether or not it corresponds to a valve opening region on a control map on the basis of these signals. A valve 15 is closed in the running region of small gas flow rate to a turbine 4 and opened when the gas flow rate exceeds a predetermined value. When the valve 15 is closed to intercept a communicating passage 14, exhaust from No.1-3 cylinders and No.4-6 cylinders flows individually into turbines 4a, 4b respectively through exhaust passages 10, 11, so that the exhaust pressure is avoided from the mutual interference, and the rotation of the turbine with low speed is improved. On the other hand, when the valve 15 is opened, the respective exhaust joins together through the communicating passage 14, so that the exhaust pressure in the upstream of the turbines 4a, 4b is reduced. |
