Method of manufacturing double-structure sound absorbing wall for motor vehicle

摘要

A method of manufacturing a double-structure sound absorbing wall having a cavity defined by joining first and second plate members, comprising the steps of providing said first and second plate members with gas bleeding holes and recesses depressed toward the inside of said cavity to abut the members to each other, providing a sound insulating member foamable by heat received in said cavity with relief holes for spot-welding corresponding to said cavity, holding said sound insulating member by said recesses upon abutting of said plate members, abutting said peripheral edges to each other, spot-welding said recesses to each other to close said cavity, and foaming said sound insulating member by heating to fill said cavity therewith.