A particulate trap for a diesel engine

摘要

A particulate trap for a diesel engine in which at least two nonwoven sheets (1a,1b) made of heat-durable metallic fibers and at least two corrugated plates (2a,2b) made of heat-durable metal having a width smaller than that of the nonwoven sheets are alternately overlaid in the thicknesswise direction with each other in a spiral manner, and one surface of one of the nonwoven sheets and one surface of the other of the nonwoven sheets are in close contact and are continuously welded to each other along the upstream edges thereof as seen from the flowing direction of the exhaust gas so that a first space (S1) closed along the upstream edges and opened along the downstream edges is formed between the nonwoven sheets via one of the corrugated plates, and the other surface of the one nonwoven sheet and the other surface of the other nonwoven sheet are in close contact and are continuously welded to each other along the down stream edges thereof as seen from the flowing direction of the exhaust gas so that a second space (S2) closed along the downstream edges and opened along the upstream edges is formed between the nonwoven sheets via the other of the corrugated plates, is disclosed. In the particulate trap, the difference in width between the nonwoven sheet and the corrugated plate is larger in a central zone of the particulate trap than in the circumferential zone thereof.