US Patent 10385810 Intake system of internal combustion engine with supercharger

An intake system of an internal combustion engine with a supercharger includes: a negative pressure control valve which is disposed in the upstream side than an intake side supercharger in an intake passage; a first external gas introduction passage which introduces a single external gas made of blow-by gas, at a part of the intake passage which is on the upstream side of the intake side supercharger and on the downstream side of the negative pressure control valve; and a fresh air introduction passage which introduces fresh air to an internal combustion engine main body from the upstream side of the negative pressure control valve.