Pulsating-gas silencer with variable damping characteristics

摘要

The silencer is particularly for an engine exhaust, having a housing (1) with inlet and outlet pipes (2,3) and containing intermediate pipes (4,5) and/or partitions (6,7). These form a first long gas passage (A) of reduced cross-section and a second (B) short one of large cross-section. A closing plug (12) working against a seat (11) is moved by an actuator (13) dependent on gas pressure. A nozzle (10) is mounted in the inlet pipe or one directly connected to it, and generates a vacuum to operate the actuator. The nozzle can be of the Venturi or Laval type, and the actuator can consist of a folding bellows or a membrane capsule, while the plug can be a plate valve. The end of one of the pipes (2,4,5) can form the valve seat, while both seat and plug can be upstream of the nozzle. Two or more nozzles, actuators and/or plugs can be provided, and one nozzle can control two or more actuators, which can have different characteristics.