SCROLL STRUCTURE OF TURBINE HOUSING

摘要

An object of the invention is to provide a scroll structure of a turbine housing of a twin scroll turbocharger of which flow-through abilities of two exhaust gas passages are equal to each other. A tongue (44), which partitions a scroll portion (26) into an outer peripheral portion (26a) and an inner peripheral portion (26b) in a longitudinal section parallel to a flow direction of an exhaust gas, is formed at the turbine housing (32), the tongue (44) includes a front-side tongue (46) and a rear-side tongue (48) that respectively close the two exhaust gas passages at the outer peripheral portion (26a) in a cross-section, and respective inner sides (46a, 48a) of the front-side tongue (46) and the rear-side tongue (48) and respective minimal outflow width portions (56a, 58a) of a front-side passage (22) and a rear-side passage (24) are formed substantially parallel to each other in the cross-section at a downstream end of the outer peripheral portion (26a).