Adjustable diaphragm for exhaust-gas flow through catalyser for motor vehicle IC engine

摘要

An adjustable diaphragm to control the exhaust flow of IC engines has the diaphragm opening limiting the volume flow to a certain part of the flow region of the catalyser. The unused sealed-off region shaded by the diaphragm is thereby conserved. The opening can be changed in its effective cross-sectional area by an actuator. The flow speed of the exhaust in the active part of the catalyser is adjustable by the actuator. The opening focuses the exhaust volume flow in the starting position upon a heated zone. During the starting process, the exhaust is conducted through the small pre-heated zone and conserves the unheated catalyser part. After the heat-up time of the ignited catalyser, the diaphragm can be extended from the starting position to an operating position since the unheated catalyser part has reached a uniform working temperature by the exhaust heat.