| 摘要 |
An exhaust pipe assembly (10) is provided for achieving a quick light-off of a catalytic converter (20). Exhaust pipe assembly (10) comprises circuitously bent inner (30) and outer pipes (32) disposed in generally concentric relationship to one another. The inner pipe (30) is formed from a very thin metal to provide a low thermal mass and a correspondingly low heat dissipation therefrom. The outer pipe (32) is thicker to provide structural support, and defines an air insulation barrier around the inner pipe (30) to further reduce heat dissipation. The inner pipe (30) is corrugated at selected locations (34,36) that will correspond to bends (23,24) in the circuitous exhaust pipe assembly (10). The thin-walled locally corrugated inner pipe (30) is then inserted into the outer pipe (32), and the assembly (10) is bent into the required configuration. The corrugations (34,36) support the inner (30) and outer (32) pipe relative to one another during the bending process and during use. The bent pipe assembly (10) then is connected to the catalytic converter (20) for subsequent mounting to vehicle engine. <IMAGE> |
