ANNULAR BEAD FORMING METHOD FOR WARM-KEEPING TYPE EXHAUST PIPE

• Main Authors: YAMADA TATSUKI, KAWAMATA AKIHIRO, HOSODA FUMIO, HISANAGA TORU, FURUHASHI KAZUHIRO
• Format: Patent
• Language: English
• Published: 07.12.1999
• Edition: 6
• Subjects: BLASTING; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ENGINES; WEAPONS

PROBLEM TO BE SOLVED: To form annular beads for a warm-keeping type exhaust pipe of such a structure that an inner pipe and an outer pipe are installed in double structural configuration wherein one end of the inner pipe is attached fast to one end of the outer pipe and the ring-shaped beads formed on the periphery of the other end of the inner pipe are fitted slidably in the outer pipe. SOLUTION: Beads forming projections 33a of a pipe expanding die 30 are inserted into other end of an inner pipe 10 in such a condition that the die segments 301 -306 are contracted diametrically, and a wedge 44 is inserted by pressure into a wedge hole 36 provided in the die 30 using a fluid cylinder so that the die segments 301 -306 are displaced to the specified diametric enlargement position, and thereby the whole peripheral surface of each projection 33a is put in tight attachment to the inner surface of the outer pipe 11 through the peripheral wall of the inner pipe 10. Thereby beads in genuine circular form 14 substantially are formed on the peripheral surface of the other end of the inner pipe 10.