| 摘要 |
A light and compact two-stage supercharging exhaust turbocharger is provided which is capable of reducing the weight and the number of components, of reducing the number of assembling processes using a bolt, and of reducing the number of separating processes in a narrow engine room in such a manner that an exhaust manifold portion, in which an exhaust manifold and a high-pressure turbine housing of a high-pressure-stage supercharger are formed into a single body by casting, is integrally formed with a low-pressure-stage connection portion mounted with an exhaust gas control valve. In a two-stage supercharging exhaust turbocharger including: a high-pressure-stage supercharger having a high-pressure turbine driven by exhaust gas discharged from an exhaust manifold of an engine; a low-pressure-stage supercharger having a low-pressure turbine driven by the exhaust gas used to drive the high-pressure-stage supercharger, the high-pressure-stage supercharger and the low-pressure-stage supercharger being arranged in series in an exhaust gas passageway; and an exhaust gas control valve configured to selectively change flow rates of the exhaust gas passageways of the high-pressure-stage supercharger and the low-pressure-stage supercharger, wherein an exhaust manifold incorporating casing is configured by integrally forming the exhaust manifold, a high-pressure turbine housing of the high-pressure-stage supercharger, and a valve casing accommodating the exhaust gas control valve. |
