To obtain the desired supercharged pressure according to the engine operating state without increasing fuel consumption of the engine, by preventing exhaust gas from flowing from an inner peripheral scroll part to an outer peripheral scroll part.
Communication passages 30a are provided so that each vane part 34 of an involute partition wall 30 formed between the mutually adjacent communication passages 30a has a downstream first surface 34a extending in the tangential direction of the inner peripheral surface of the partition wall 30 and an upstream second surface 34b extending in parallel with the first surface. The peripheral length of each vane part 34 is set to the length in which the normal line passing the inner peripheral scroll part side end (a) in relation to a straight line linking the inner peripheral scroll part side end (a) and the outer peripheral scroll part side end (b) to each other intersects the vane part 34 arranged on the downstream side.
KAWAGUCHI JUN
ADACHI KAZUNARI
KONO SHINJI
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