SCREW FORM ROLLING DIE MANUFACTURING METHOD

• Main Authors: MIYAHARA HIROSHI, TAKEMASU MITSUIE
• Format: Patent
• Language: English
• Published: 09.12.2004
• Edition: 7
• Subjects: MACHINE TOOLS; MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS,WHEELS, RINGS, BARRELS, BALLS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; PUNCHING METAL; THREAD CUTTING; TRANSPORTING; WORKING OF SCREWS, BOLT HEADS, OR NUTS, IN CONJUNCTIONTHEREWITH

PROBLEM TO BE SOLVED: To provide a screw form rolling die manufacturing method to be used for manufacturing a multiple screw bolt with slack-preventive function such as a double screw bolt. SOLUTION: A first cutting tool 10 having a shape of a flat ridge portion of a coarse screw thread is fed into a screw form rolling die material 30 to the position not greater than the maximum height of a projection 6 forming a part of a fine screw thread to be periodically formed in a valley portion of the coarse screw thread according to the phase deviation between the fine screw thread with the fine screw developed and the coarse screw thread with the coarse screw developed. Then, a part of the screw form rolling die material 30 is cut to form a part of the coarse screw thread on the screw form rolling die. In addition, a second cutting tool 20 having a shape of the fine screw thread is fed to the shape of the projection 6 from a valley portion 5a of a part of the coarse screw thread formed on the screw form rolling die, and the screw form rolling die material 30 is cut to form a remaining portion of a part of the coarse screw thread and the projection 6 of the screw form rolling die. COPYRIGHT: (C)2005,JPO&NCIPI