| 摘要 |
PURPOSE:To prevent a resin part from being damaged and leakage from between metal and resin by making buried length of a metal insert approximately 1/5 or less of a whole thread length from a reference diameter toward a small diameter of a female screw at the time of molding the female screw for pipe of a resin material. CONSTITUTION:Resin injected into a metal mold 1 surrounds a metal insert 3 and at the same time a screw part (p) is molded by an insert piece 2. After the resin is hardened, the insert piece 2 is removed while it is rotated to obtain a mold of a resin-molded female screw. At the time of manufacturing, a buried size L1 of the metal insert 3 is made approximately 1/5 or less of a whole thread length L from a reference diameter (d) toward a small diameter (d') of the female screw. Since an error in processing the screw or force at the time of coupling is reinforced by the metal insert 3, no damage will occur on a resin part H. In addition press-fit screwing between the thread (p) of the resin part H and a male screw (m) on an opposite side 4 prevents fluid, so that there is no leakage of fluid between the metal insert 3 and the resin. |
