| 摘要 |
PROBLEM TO BE SOLVED: To obtain a screw component which accurately secures set axial force without an increase in screwing torque and minimizes the generation of molding chips even at re-screwing work. SOLUTION: In the screw component keeping a screw thread 10 on a leg 3. In a cross section orthogonal to a ridgeline 21 of the screw thread 10, a following flank angle (α/2) and leading flank angle (α/2) on a screw thread base side are equal to each other up to a prescribed height (h) from a valley part 11. A following flank surface 14 is steep from the prescribed height (h) to the ridgeline 21, which is made smaller than the following flank angle (α/2). A ridgeline 20 having a second flank angle (β) of an obtuse angle larger than a first flank angle (α) is formed on the thread ridgeline side. Since the steep following flank surface 14 and a first leading flank surface 13 are respectively connected to the ridgeline 20, large axial force is generated at the completion of screwing, thereby realizing firm fastening. COPYRIGHT: (C)2011,JPO&INPIT |
