PURPOSE: To improve operating responsiveness in the whole operating region with simple constitution by disposing turbines respectively in plural passages respectively communicated with an exhaust passage, and driving both turbines in series during the low speed operation of an engine, while driving both turbines in parallel during high speed operation.
CONSTITUTION: A first turbine 21 is disposed at a first passage 31 communicated with the exhaust passage 31 of an internal combustion engine 1, and a second turbine 22 connected to the first turbine 21 is disposed at a second passage 32 that can be also communicated with the exhaust passage 3. A compressor 11 connected to both first and second turbines 21, 22 is disposed at the intake passage 2 of the internal combustion engine 1. Plural switching means 41, 42 are disposed to communicate/cut off the second passage 32 with/from the exhaust passage 3 and to communicate/cut off both first and second passages 31, 32 mutually. Both first and second turbines 21, 22 are thereby driven in series during the low speed operation of the internal combustion engine 1, and both first and second turbines 21, 22 are driven in parallel during high speed operation.
MAEDA TAKASHI
KUBO KENZO
MITSUBISHI MOTORS CORP