Method of manufacturing injection molding manifold having a melt passage with an elbow

摘要

A method of making an injection molding melt distribution manifold wherein the melt passage branches through a number of elbows leading to different gates. Each elbow is preformed in a cylindrical plug which fits in a bore in an outer end of the manifold in alignment with a lateral portion of the melt channel. A brazing hole with an upward mouth is drilled in the outer surface of the plug and nickel alloy brazing powder is poured into it. After insertion into the bore in the manifold, the plug is rotated with a suitable tool to a predetermined position with the mouth of the brazing hole pointed downward. The manifold is then heated in a vacuum furnace to integrally braze the plugs in place simultaneously with brazing an electrical heating element in a channel in the manifold. The melt passage is then completed by drilling an outlet bore from the front face of the manifold to the outlet of each elbow.