SWAGE AUTOFRETTAGE METHOD FOR THICK CYLINDRICAL BODY

摘要

PURPOSE:To surely give a thick cylindrical body high autofrettage ratio by shifting under pushing tapered part in a pushing member into inner part space in the metal- made thick cylindrical body, expanding outer diameter in the thick cylindrical body and giving high compressive residual stress to near the inner surface thereof. CONSTITUTION:On a bed 7, a guiding core punch 4, cylindrical core punch 5 and flange part 6 are laid in order and the metal-made thick cylindrical body 1 applying lead plating in inner part, is inserted into the flange part 6 and the flange part 1b is locked with the flange member 6. Successively, while directing a guide part 2e downward, the pushing member 2 providing the tapered part 2c applying Cr plating, is inserted from a large diameter part 1d side in the inner part space in the thick cylindrical body 1, and the tapered part 2c downward is engaged with the tapered part 1f downward. Under this condition, pressing force is acted on a pressing rod 3 to press the pushing member 2 is pushed into the thick cylindrical member 1 and guided into a small diameter part 1e with the guide part 2e, and the pushing member 2 is shifted into the thick cylindrical body 1 to apply a swage autofrettage to the thick cylindrical body 1. By this method, the high compressive residual stress to the peripheral direction is given to near the inner surface in the small diameter part 1e.