| 摘要 |
PURPOSE:To obtain the curved cylindrical ferrite without distorting the cylindrical body even if the ferrite is thin by sintering the curved cylindrical degreased molding obtd. by combining a cylindrical extrusion molding of a required length made by extrusion molding and a rod or cylinder made of a shape memory resin and degreasing by heating. CONSTITUTION:The shape memory resin rod or cylinder 2 which has the shape recovering temp. sufficiently higher than ordinary temp. and is memorized with the necessary curved shape is inserted into the central hole of the straight cylindrical extrusion molding 1 of the required length. Namely, this resin rod or cylinder 2 restores its shape and deforms the molding 1 to the curved cylindrical shape in the state in which the molding 1 attains a slightly plastic state in the prescribed temp. region during the course of the heating up for the degreasing treatment by the heating of the molding 1. The shape recovery of the resin rod or cylinder 2 is effected by the degreasing treatment by the above-mentioned heating and the resin rod or cylinder 2 is decomposed, burned and expended simultaneously with the binder, such as fats and oils, compounded with the molding 1. The curved ferrite core obtd. in such a manner prevents the influence of electromagnetic noises at the higher degree than heretofore in a small space and acts to protect the curved part of a signal line when this core is provided by being inserted in the curved part of the signal line. |
