Coil resin molding method for microwave oven transformer, involves injecting resin into metallic mold after inserting assistant tool along with coil into cavity so as to form resin coating on coil

摘要

The coil resin molding method involves inserting coil (31) in the assistant tool for gap maintenance (41) and inserting assistant tool into the cavity (36) of metallic mold (35). The fused resin is injected into the metallic mold so as to form resin coating on the coil. The assistant tool is molded by a resin different from the resin for resin coating or of the same of the material of resin coating. The assistant tool is formed in the shape of net so that the coating resin contacts the coil sufficiently during molding time. Projections are formed on the lateral surface of the assistant tool for securing thickness of resin coating necessary for insulation and heat release of the coil. The winding wire of the coil is directly carried to the assistant tool so as to maintain the gap between the coil and the cavity. The coil with which the interval maintenance portion is formed in secondary metallic mold finally forms resin covering. The interval maintenance portion is formed on the multi stage in order to prevent peeling with resin coating by secondary injection.