Turbocharging system for internal combustion engine

Abstract

A two-stage turbo system using small-sized turbo-superchargers and simply configured. A two-stage turbo system provided with an internal combustion engine (1), two turbo-superchargers (2A, 2B) driven by exhaust gas from the internal combustion engine (1), control valves (V1-V5) for switching between the flow path of intake gas sucked into the internal combustion engine (1) and the flow path of exhaust gas from the internal combustion engine (1), and a control device for controlling the control valves (V1-V5) and the turbo-superchargers (2A, 2B). The two turbo-superchargers (2A, 2B) have the same turbine capacity, function respectively as the high-pressure side turbo-supercharger (2A) on the exhaust path upstream side and the low-pressure side turbo-supercharger (2B) on the exhaust path downstream side, and have, by switching between the flow paths by using the control valves (V1-V5), a series mode in which the two turbo-superchargers (2A, 2B) are serially connected to each other, a one-stage supercharging mode in which gas flows only to the high-pressure-side turbo-supercharger (2A) or only to the low-pressure-side turbo-supercharger (2B), and a parallel mode in which the two turbo-superchargers (2A, 2B) are connected in parallel to each other.

Dependencies are inferred from the claim text.