Denso Corporation

Hitachi Powdered Metals Co., Ltd.

Sumitomo Electric Industries, Limited

Sumitomo Electric Sintered Alloy, Ltd.

Tsuyoshi Akao

Kazuo Asaka

Chio Ishihara

Kei Ishii

Isao Makino

Kohei Muramatsu

Hirotake Hamamatsu

Tamio Takada

Takao Nishioka

Naoto Igarashi

Yoshiyuki Shimada

Aya Hamano

A soft magnetic material includes a plurality of composite magnetic particles including a metal magnetic particle and an insulating film surrounding a surface of the metal magnetic particle. The insulating film also contains a phosphate. The soft magnetic material further includes an aromatic polyetherketone resin and a metallic soap and/or an inorganic lubricant having a hexagonal crystal structure. The metallic soap and the inorganic lubricant are particles with an average particle size of not more than 2.0 &#x3bc;m.

Soft magnetic material and dust core

A method for producing a soft magnetic powdered core includes preparing a mixture of a soft magnetic powder and a resin powder, compacting the mixture into a predetermined shape so as to obtain a compact, and heating the compact. The resin powder has a median size of not more than 30 &#x3bc;m, a maximum particle size of not more than 100 &#x3bc;m, and a specific surface area of not less than 1.0 m/cm, and the additive amount thereof is 0.005 to 2 vol %.

Method for producing soft magnetic powdered core

A method for producing a soft magnetic powdered core comprises a mixing step for forming a raw powder by adding a thermoplastic resin powder to a soft magnetic powder and mixing them, a compacting step for forming a compact by compacting the raw powder into a predetermined shape, a melting and setting step for the resin in which the resin of the compact is melted by heating to at least the melting point of the thermoplastic resin and the melted resin is set by cooling to a room temperature, and a crystallizing step for the resin in which the set resin is heated to not less than the exothermic onset temperature and not more than the endothermic onset temperature, which are measured by DSC analysis of the thermoplastic resin, and is cooled to a room temperature.

A sintered plunger is used for electromagnetic actuators. The sintered member includes: an outer member composed of a soft magnetic material and having an inner hole formed therein, and a shaft having an end portion which is fitted into the outer member. The shaft is composed of a ferromagnetic steel, the outer member peripheral is composed of a sintered member, and the shaft and the outer member are integrally bonded by sintering. As a result, the overall sintered plunger can have good magnetic properties, a good magnetic attraction, a good wear resistance, and a good fatigue strength. Electromagnetic actuators having high responsiveness required in recent years can be produced.

Sintered plunger and production method therefor

The present invention provides a production method for a powdered core, including steps of preparing a mixture including a soft magnetic powder and a resin powder to obtain a mixture, compacting the mixture into a predetermined shape to obtain a green compact and heating the green compact, and wherein the resin powder has a median size of not more than 50 &#x3bc;m, and the resin powder amount is 0.01 to 5 vol %. The method reduces production cost, and decreases eddy-current loss Wand hysteresis loss W, whereby a powdered core in which a durability is improved and the technical advantages are expanded can be provided.

Production method for powdered core

Growing community of inventors

Kariya, Japan

Tsuyoshi Akao