Internal combustion engine supercharged by an exhaust gas turbo-charger

摘要

In the case of an internal combustion engine supercharged by an exhaust gas turbo-charger, a bypass line is laid between the charge air manifold and the exhaust gas manifold. A combined bypass/blow-off device is proposed for this purpose which incorporates a blow-off valve and a bypass valve. This device comprises an axially displaceable bypass valve connected into a bypass line, to which valve a passage control element is assigned. The latter has a passage duct for bypass charge air and a valve seat for the bypass valve. In addition the said passage control element is designed and arranged in the bypass line in such a way that it can also assume the function of a blow-off valve. The design and arrangement are at the same time so selected that following a shut-off of the passage duct by the bypass valve then lying on its valve seat it can be displaced under the action of the said bypass valve against a return force and is capable of opening a blow-off line by moving off an associated valve seat. This line branches off from the bypass line in the area of the passage control element and is separated off from this by appropriate means which prevent migration of charge air into the blow-off line and migration of exhaust gases from the blow-off line into the closable part of the bypass line.