METHOD OF MANUFACTURING OUTER TUBE OF INJECTOR

摘要

A method of manufacturing a tube of an injector having a cylindrical part with an excellent roundness and capable of preventing deformation and warpage from occurring thereon, comprising the steps of injecting molten resin (R) into the cavity (17) of a metal mold (11) comprising a fixed mold (13) having a hole part (12) formed along the outer shape of the injector outer tube (1) provided therein, a movable mold (14) closing the hole part (12), and a core (15) inserted into the hole part (12), injecting the molten resin (R) into a cylindrical hollow part (21) communicating with the flange formed part (20) of the hole part (12) from a spool (22) and a runner (23) through a submarine gate (24) to lead the molten resin (R) into the cavity (17), force−feeding the resin inside the cylindrical hollow part (21) into the cavity (17) by a push pin (25) installed in the cylindrical hollow part (21) when the molten resin comes into semi−molten state, and when the molten resin (R) is not filled sufficiently into the cavity (17), the wait position of the push pin (25) is changed in the direction of moving apart from the connection part of the submarine gate (24) and the molten resin (R) is injected to re−fill the insufficient resin into the cavity (17).