Patent ID: 8087244

Claim:
A method of operating an internal combustion engine having a combustion unit; an air filter; a throttle; an intake air conduit connected to the combustion unit, said intake air conduit having two separate conduit sections, a first section of the air intake conduit having a first end connected to an outlet of the air filter and a second end connected to an inlet of the throttle; and a second section of the air intake conduit connecting an outlet of the throttle to the combustion unit, wherein the throttle valve is arranged in the intake air conduit between the first and second sections; an exhaust gas conduit connected to the combustion unit; a turbo-engine connected to the intake air conduit by a supply conduit connected upstream of the throttle and by a discharge conduit connected downstream of the throttle; a compressor operatively driven by the turbo-engine and connected by a connecting line to the exhaust gas conduit; wherein said turbo-engine and said compressor are both arranged separated from said air filter, a valve arranged in the discharge conduit; a vacuum cell actuating the valve; an electro-pneumatic converter operatively connected to the vacuum cell; wherein the electro-pneumatic converter in a first state is operable to lock the vacuum cell preventing the vacuum cell from switching regardless of differential pressure, wherein the electro-pneumatic converter in a second state is operable to release the vacuum cell so the vacuum cell is able to switch at the predefined differential pressure, the method comprising the steps of: generating a vacuum pulse in the intake air conduit and also in the discharge conduit when starting the internal combustion engine with the throttle being closed; suddenly opening the valve by the vacuum pulse reaching a defined differential pressure in the discharge conduit; loading the turbo-engine with the defined differential pressure as the valve opens suddenly; charging secondary air into the exhaust gas conduit with the compressor driven by the turbo-engine.