PURPOSE: To work a cylindrical body having a taper at the peripheral surface of the bottom part thereof and the like easily and efficiently by punching a work while pressing and deforming the bottom surface of the work.
CONSTITUTION: The work 9 consisting of the elastic body such as polyrethane foam is placed on a punching die 30 having a cut-away recessed surface 31 slightly larger in diameter than a cutting tool 21, and the tool 21 is lowered to punch out the work 9 into a cylindrical shape. Since the peripheral part of the punched surface 9 of the work 9 is puched out in the condition of being expanded into the recessed surface 31, the peripheral surface of the bottom part is provided with the taper 12. When an expanded part 32 is provided on the die, the peripheral part of the punched surface 9' is deformed toward the center, so that a cylindrical body having a tapered curved surface 13 larger than a main body part 11 is obtained. Accordingly, the cylindrical body having a taper at the peripheral surface of the bottom part thereof, such as a bottle stopper or an earplug, can be punched out easily in one step.
KONDOU YUTAKA
YAMAMOTO TAKU
HITAI TAKAO
| JPS52117376A | 1977-10-01 | |||
| JPS4886147A | 1973-11-14 | |||
| JP40005753A |