Exhaust system conduit with thermal/noise insulation

Abstract

A flexible conduit for use in a pipe system such as a vehicular exhaust system to provide a torsional or non-torsional joint between two pipes. The conduit has an outer bellows and an inner liner between which a layer of noise/thermal insulation is sandwiched to attenuate noise, resist thermal transmission and dampen vibration.

What is claimed is: 
     
         1 . A flexible conduit structure for coupling first and second pipes, comprising:
 a conduit having first and second ends for connection with said first and second pipes, respectively;   an outside portion of said conduit constructed in a manner to provide flexibility to said conduit;   an inside portion of said conduit connected to said outside portion and arranged to provide a bore through said conduit for the passage of fluid therethrough; and   an insulation blanket sandwiched between said outside and inside portions, said blanket being constructed to suppress noise and heat transmission from within said conduit.   
     
     
         2 . A conduit structure as set forth in  claim 1 , including a covering substantially surrounding said outside portion of said conduit. 
     
     
         3 . In a vehicle exhaust system, the combination of:
 first and second pipes and a conduit extending between and coupled with said first and second pipes;   an outside portion of said conduit having a plurality of corrugations to accommodate flexing of said conduit;   a liner on said conduit providing a flow channel through which vehicle exhaust gases can flow, said liner being connected with said outer portion of said conduit; and   an insulation blanket sandwiched between said liner and said outside portion of said conduit, said blanket being constructed of a material effective to suppress noise and heat transmission from within said conduit.   
     
     
         4 . The combination of  claim 3 , wherein said liner comprises a metal strip arranged in a helical winding. 
     
     
         5 . The combination of  claim 3 , including a covering substantially surrounding said conduit. 
     
     
         6 . The combination of  claim 5 , wherein said covering comprises a wire braid. 
     
     
         7 . A flexible conduit structure for a vehicle exhaust system, comprising:
 a conduit having a liner forming a flow passage for flow of vehicle exhaust gases therethrough and an outer corrugation body having a plurality of corrugations to provide flexibility of said conduit;   a pair of end fittings on opposite ends of said conduit for connection to respective pipes between which said flow passage directs vehicle exhaust gases; and   a layer of insulation between said liner and said corrugated body constructed and arranged to suppress noise and heat transmission from within said conduit.   
     
     
         8 . A conduit structure as set forth in  claim 7 , including a covering substantially enclosing said conduit.