Method and device for simultaneous regulation of an intake air flow for an internal combustion engine and a secondary air flow in the exhaust system of the same internal combustion engine

Abstract

A method and an apparatus are described for the simultaneous adjustment of an air intake stream of an internal combustion engine and of a secondary air stream into the exhaust system of the internal combustion engine, the secondary air stream being produced by a compressor which is driven by a turbine . The turbine is housed in a bypass duct , the bypass duct being arranged parallel to a throttle valve in the air intake tract of the internal combustion engine. Thus the required amount of secondary air is dependent upon the throttle valve setting. To create compensation for this, a control valve , for example, is created, which is connected through a connecting duct to the secondary air duct . The control valve affects the cross section of the bypass line , so that in the event of an opening of the throttle valve the cross section of the bypass duct can be expanded simultaneously, so that the pressure drop at the turbine, produced by throttle valve opening can be compensate. Alternatively the arrangement of a control valve is possible, which is operated by a control unit. Moreover, a mechanical coupling of the throttle means in the bypass line and the throttle valve is possible. The proposed method achieves the simultaneous adjustment of air intake flow and secondary air flow with reasonable design expense and therefore constitutes an economical solution.