Method for manufacturing cap nut

Abstract

Abstract PURPOSE: To manufacture a cap nut to be used for coupling and joint excellent in dimensional accuracy and mass-productivity, by working to form in two processes on a pipe being cut down to prescribed length by cold or hot forgings, and then, by cutting grooves for a screw and a washer by machining. CONSTITUTION: A pipe 21 cut down to a prescribed length (l) and having an almost uniform thickness (t) is put into a metal mold 22, and a punch 23 having a diameter reducing stepped section is inserted into the pipe 21, and then, the pipe 21 is formed to become a member (a) by pushing the punch 23 under a cold or hot condition. The member (a) is formed such a way that the front end section 25 is reduced in diameter and a thickened-wall part 26 which swells inward is formed at the central section. This member (a) is put into another metal mold 27 and a projection type punch 28 inserted into the member (a). Then, the punch 28 is pushed under a cold or hot condition, and a ring-type stepped part 33 at the boundary of the larger diameter section 30 and smaller diameter section 31, a tapered hole along the inner surface of the small diameter section 31, and a ring-type projection 32 at the end of the smaller diameter section 31 are formed, respectively. This member (b) is then subjected to a machining, and a ring-type groove for washer 34 above the stepped part 33 and threads 35 into the inner surface of the larger diameter section 30 are cut, respectively. Vertical grooves 36 are cut into the outer surface of the side section of the larger diameter section 30, is required. COPYRIGHT: (C)1982,JPO&Japio

Inventors

• 👤 Toshitaka Sugiuchi
• 👤 Susumu Aoyama
• 👤 Akinobu Takezoe

Bibliographic Details