| 摘要 |
PURPOSE:To prevent a molding material from flowing in a screw hole without applying post-processing to a nut, by a method wherein an end face of an insert pin abuts against one side flat face of a nut set up within a mold and an end face of a sleeve is faced on the other side flat face of the nut at a slight gap. CONSTITUTION:A pin part 15, whose length is longer than a thickness of a nut 7 and the outside diameter D is the same as the standard smallest inside diameter dmin of a JIS standard of a screw hole 7', is provided on an end face 14 of an insert pin 13 in a protruded state. On the one hand, a sleeve 17 whose outside diameter D1 has been formed identically with that of a flat face 16 of the nut 7 is provided, on which an insertion hole 18 of the pin part 15 has been kept formed concentrically with the sleeve 17. One side flat face 16 of the nut 7 abuts against the end face 14 of the insert pin 13 by piercing the pin part 15 of the insert pin 13 through the screw hole 7' of the nut 7 and the nut 7 is set up within a mold under this condition. Then molding resin is cast by situating an end face 19 of the sleeve 17 at a distance identical with the standard maximum thickness of a JIS standard of the nut 7 from the end face 14 of the insert pin 13. With this construction, a trouble that a molding material flows in a threaded part of the nut can be avoided. |
