Abstract: A flexible tube 10 of the present invention is disposed downstream of a exhaust path from an engine E, and formed of an outer bellows 3 as an outer tube and an inner bellows 4 as an inner tube; pleats 4c,4c of the inner bellows 4 are smaller in depth and pitch than the pleats 3c of the outer bellows 3, and the buffering space S is provided with a gap t between the pleats bottoms of the outer bellows 3 and the pleats tops of the inner bellows 4, and further, a partition 17 that splits the exhaust path is disposed in the inner bellows 4. For this reason, sound insulation effect is improved, and the lowering of the temperature of the exhaust gas is suppressed, leading to quick temperature rise of the exhaust gas to be fed into the catalytic converter, thereby promoting the activation of the catalysts and improving the capability to purify exhaust gas, and the exhaust efficiency can be improved thereby increasing output performance of the engine.

Abstract: A to be-processed portion of an inner panel formed by stamping a steel plate is overlaid, in a thickness direction thereof, with a to-be-processed portion of a reinforcing member formed by stamping a steel plate. The inner panel and the reinforcing member are joined and integrated by a spot welding apparatus, thereby obtaining an intermediate article. A material handling robot puts off the intermediate article from the spot welding apparatus, conveys it to a pressing apparatus, and sets it against the pressing apparatus. The to-be-processed portion of the inner panel and the to-be-processed portion of the reinforcing member are subjected to piercing by the pressing apparatus.

Abstract: A flexible tube 10 of the present invention is disposed downstream of a exhaust path from an engine E, and formed of an outer bellows 3 as an outer tube and an inner bellows 4 as an inner tube; pleats 4c,4c of the inner bellows 4 are smaller in depth and pitch than the pleats 3c of the outer bellows 3, and the buffering space S is provided with a gap t between the pleats bottoms of the outer bellows 3 and the pleats tops of the inner bellows 4, and further, a partition 17 that splits the exhaust path is disposed in the inner bellows 4. For this reason, sound insulation effect is improved, and the lowering of the temperature of the exhaust gas is suppressed, leading to quick temperature rise of the exhaust gas to be fed into the catalytic converter, thereby promoting the activation of the catalysts and improving the capability to purify exhaust gas, and the exhaust efficiency can be improved thereby increasing output performance of the engine.