Secondary air supply system for an engine exhaust gas purifying system

摘要

A secondary air supply system for an engine exhaust system in which the secondary air is drawn to the engine exhaust passage under the suction pressure produced in the exhaust passage. The secondary air supply system includes a non-return valve connected with the engine exhaust passage and an expansion chamber connected with the non-return valve through an elongated connecting passage. The expansion chamber is formed in a casing and the non-return valve is located in a valve chamber formed in the casing and separated from the expansion chamber by a partition wall. The connecting passage is formed by a pipe extending in the expansion chamber from the partition wall.