Patents by Inventor Kazuo Asaka
Kazuo Asaka has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8062583Abstract: 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 ?m, a maximum particle size of not more than 100 ?m, and a specific surface area of not less than 1.0 m2/cm3, and the additive amount thereof is 0.005 to 2 vol %.Type: GrantFiled: March 17, 2008Date of Patent: November 22, 2011Assignees: Hitachi Powdered Metals Co., Ltd., Denso CorporationInventors: Chio Ishihara, Kazuo Asaka, Kohei Muramatsu, Tsuyoshi Akao, Hirotake Hamamatsu
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Patent number: 8029626Abstract: 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.Type: GrantFiled: March 17, 2008Date of Patent: October 4, 2011Assignees: Hitachi Powered Metals Co., Ltd., Denso CorporationInventors: Chio Ishihara, Kazuo Asaka, Kohei Muramatsu, Tsuyoshi Akao, Hirotake Hamamatsu
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Patent number: 7649298Abstract: A claw teeth type electric rotary machine comprises a stator including an annular core with claws formed from a powder core and an annular coil installed inside the annular core, and a rotor rotatably positioned inside the stator. An inner edge of the annular core is provided with plural claw poles which are protruded at a predetermined interval in a circumferential direction and extended in an axial direction of the annular core so as to alternately meshes with each other. The stator comprises the annular core with claws, the annular coil, and a molded nonmagnetic potting material filled between the annular core with claws and annular coil, so that the annular core with claws and annular coil are integrated with the molded potting non-magnetic material.Type: GrantFiled: July 24, 2007Date of Patent: January 19, 2010Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Powered Metals Co., Ltd., Japan Servo Co., Ltd.Inventors: Yuji Enomoto, Motoya Ito, Masashi Kitamura, Ryoso Masaki, Katsuyuki Yamazaki, Shoji Ohiwa, Yasuaki Motegi, Kazuo Asaka, Chio Ishihara
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Patent number: 7592734Abstract: A three-phase permanent magnet brushless motor comprises a stator having three-phase windings, and a rotor having a permanent magnet with a plurality of poles for serving as a field magnet. The stator comprises a stator core which includes a powder core that is compacted at a high density in at least teeth thereof. A combination of the number of magnetic poles of the rotor with the number of slots of the stator satisfies a condition that a least common multiple of the number of slots and the number of magnetic poles is 60 or more in a region in which the number of magnetic poles is 16 or less, and the number of slots is 12 or less. The powder core is made by compacting magnetic powders to have a green density of 7.5 g/cm3 or higher.Type: GrantFiled: August 17, 2006Date of Patent: September 22, 2009Assignees: Hitachi Industrial Equipment System Co., Ltd., Japan Servo Co., Ltd., Hitachi Powered Metals Co., Ltd.Inventors: Yuji Enomoto, Akeshi Takahashi, Motoya Ito, Ryoso Masaki, Katsuyuki Yamazaki, Masahide Yamazaki, Masashi Kitamura, Chio Ishihara, Kazuo Asaka, Shoji Ohiwa, Yasuaki Motegi
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Patent number: 7541906Abstract: 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.Type: GrantFiled: September 15, 2004Date of Patent: June 2, 2009Assignees: Hitachi Powdered Metals Co., Ltd., Denso CorporationInventors: Kazuo Asaka, Tsuyoshi Akao, Aya Hamano
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Patent number: 7470332Abstract: A soft magnetic sintered member having uniform dispersion of alloy elements and a production method for the same at low cost are provided. The soft magnetic sintered member consists of, all in mass %, 2.9 to 7% of Cr; 1.5 to 6.88% of Si; and the balance of Fe and inevitable impurities. The production method for a soft magnetic sintered member includes: preparing an Fe alloy powder consisting of 3 to 7 mass % of Cr, 1.5 to 3.5 mass % of Si, and the balance of Fe and inevitable impurities; or a mixed powder in which the Fe alloy powder is mixed with an Si powder having an average particle size of 1 to 45 ?m. The production method further includes: compacting the Fe alloy powder or the mixed powder into a green compact having a predetermined shape; and sintering the green compact.Type: GrantFiled: March 29, 2005Date of Patent: December 30, 2008Assignee: Hitachi Powdered Metals Co., Ltd.Inventors: Chio Ishihara, Kazuo Asaka
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Publication number: 20080232995Abstract: 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 ?m, a maximum particle size of not more than 100 ?m, and a specific surface area of not less than 1.0 m2/cm3, and the additive amount thereof is 0.005 to 2 vol %.Type: ApplicationFiled: March 17, 2008Publication date: September 25, 2008Applicants: HITACHI POWDERED METALS CO., LTD., DENSO CORPORATIONInventors: Chio Ishihara, Kazuo Asaka, Kohei Muramatsu, Tsuyoshi Akao, Hirotake Hamamatsu
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Publication number: 20080230737Abstract: 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.Type: ApplicationFiled: March 17, 2008Publication date: September 25, 2008Applicants: HITACHI POWERED METALS CO., LTD., DENSO CORPORATIONInventors: Chio Ishihara, Kazuo Asaka, Kohei Muramatsu, Tsuyoshi Akao, Hirotake Hamamatsu
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Publication number: 20080018196Abstract: A claw teeth type electric rotary machine comprises a stator including an annular core with claws formed from a powder core and an annular coil installed inside the annular core, and a rotor rotatably positioned inside the stator. An inner edge of the annular core is provided with plural claw poles which are protruded at a predetermined interval in a circumferential direction and extended in an axial direction of the annular core so as to alternately meshes with each other. The stator comprises the annular core with claws, the annular coil, and a molded nonmagnetic potting material filled between the annular core with claws and annular coil, so that the annular core with claws and annular coil are integrated with the molded potting non-magnetic material.Type: ApplicationFiled: July 24, 2007Publication date: January 24, 2008Inventors: Yuji Enomoto, Motoya Ito, Masashi Kitamura, Ryoso Masaki, Katsuyuki Yamazaki, Shoji Ohiwa, Yasuaki Motegi, Kazuo Asaka, Chio Ishihara
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Patent number: 7273527Abstract: 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 ?m, and the resin powder amount is 0.01 to 5 vol %. The method reduces production cost, and decreases eddy-current loss We and hysteresis loss Wh, whereby a powdered core in which a durability is improved and the technical advantages are expanded can be provided.Type: GrantFiled: November 2, 2006Date of Patent: September 25, 2007Assignees: Hitachi Powdered Metals Co., Ltd., Denso CorporationInventors: Chio Ishihara, Kazuo Asaka, Kei Ishii, Tamio Takada, Tsuyoshi Akao, Isao Makino
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Publication number: 20070196231Abstract: A soft magnetic sintered member having uniform dispersion of alloy elements and a production method for the same at low cost are provided. The soft magnetic sintered member consists of, all in mass %, 2.9 to 7% of Cr; 1.5 to 6.88% of Si; and the balance of Fe and inevitable impurities. The production method for a soft magnetic sintered member includes: preparing an Fe alloy powder consisting of 3 to 7 mass % of Cr, 1.5 to 3.5 mass % of Si, and the balance of Fe and inevitable impurities; or a mixed powder in which the Fe alloy powder is mixed with an Si powder having an average particle size of 1 to 45 ?m. The production method further includes: compacting the Fe alloy powder or the mixed powder into a green compact having a predetermined shape; and sintering the green compact.Type: ApplicationFiled: March 29, 2005Publication date: August 23, 2007Applicant: HITACHI POWERED METALS CO., LTD.Inventors: Chio Ishihara, Kazuo Asaka
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Patent number: 7211158Abstract: 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 ?m, and the resin powder amount is 0.01 to 5 vol %. The method reduces production cost, and decreases eddy-current loss We and hysteresis loss Wh, whereby a powdered core in which a durability is improved and the technical advantages are expanded can be provided.Type: GrantFiled: September 30, 2003Date of Patent: May 1, 2007Assignees: Hitachi Powdered Metals Co., Ltd., Denso CorporationInventors: Chio Ishihara, Kazuo Asaka, Kei Ishii, Tamio Takada, Tsuyoshi Akao, Isao Makino
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Publication number: 20070085644Abstract: 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.Type: ApplicationFiled: September 15, 2004Publication date: April 19, 2007Applicants: HITACHI POWDERED METALS CO., LTD., DENSO CORPORATIONInventors: Kazuo Asaka, Tsuyoshi Akao, Aya Hamano
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Publication number: 20070051430Abstract: 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 ?m, and the resin powder amount is 0.01 to 5 vol %. The method reduces production cost, and decreases eddy-current loss We and hysteresis loss Wh, whereby a powdered core in which a durability is improved and the technical advantages are expanded can be provided.Type: ApplicationFiled: November 2, 2006Publication date: March 8, 2007Applicants: HITACHI POWDERED METALS CO., LTD., DENSO CORPORATIONInventors: Chio Ishihara, Kazuo Asaka, Kei Ishii, Tamio Takada, Tsuyoshi Akao, Isao Makino
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Publication number: 20070046130Abstract: A three-phase permanent magnet brushless motor comprises a stator having three-phase windings, and a rotor having a permanent magnet with a plurality of poles for serving as a field magnet. The stator comprises a stator core which includes a powder core that is compacted at a high density in at least teeth thereof. A combination of the number of magnetic poles of the rotor with the number of slots of the stator satisfies a condition that a least common multiple of the number of slots and the number of magnetic poles is 60 or more in a region in which the number of magnetic poles is 16 or less, and the number of slots is 12 or less. The powder core is made by compacting magnetic powders to have a green density of 7.5 g/cm3 or higher.Type: ApplicationFiled: August 17, 2006Publication date: March 1, 2007Inventors: Yuji Enomoto, Akeshi Takahashi, Motoya Ito, Ryoso Masaki, Katsuyuki Yamazaki, Masahide Yamazaki, Masashi Kitamura, Chio Ishihara, Kazuo Asaka, Shoji Ohiwa, Yasuaki Motegi
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Patent number: 7151334Abstract: A permanent magnet type rotor comprises an inner member 2 having an outer ring portion 21; an approximately annular outer member 1 having soft magnetism and an inner circumference contacting with an outer circumference of the outer ring portion; and plural permanent magnets 3 disposed at equal intervals on the outer circumference of the outer member toward the circumferential direction. At least one of the inner member 2 and the outer member 1 is made from a sintered material, and the inner member 2 and the outer member 1 are mutually sintered and bonded. Thickness and weight of a dynamotor itself can be reduced and high output and high efficiency can be achieved.Type: GrantFiled: September 3, 2002Date of Patent: December 19, 2006Assignees: Hitachi Powdered Metals Co., Ltd., Honda Giken Kogyo Kabushiki KaishaInventors: Kazuo Asaka, Tomoaki Arakawa, Tsuyoshi Kagaya, Satoru Shinzaki, Hiromitsu Sato, Kenji Fukuda, Hirohisa Ogawa, Tatsuro Horie, Akihiro Okamura, Katsuaki Sato, Toshiyasu Komatsu, Youichi Nakahara
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Publication number: 20040025323Abstract: A permanent magnet type rotor comprises an inner member 2 having an outer ring portion 21; an approximately annular outer member 1 having soft magnetism and an inner circumference contacting with an outer circumference of the outer ring portion; and plural permanent magnets 3 disposed at equal intervals on the outer circumference of the outer member toward the circumferential direction. At least one of the inner member 2 and the outer member 1 is made from a sintered material, and the inner member 2 and the outer member 1 are mutually sintered and bonded. Thickness and weight of a dynamotor itself can be reduced and high output and high efficiency can be achieved.Type: ApplicationFiled: June 3, 2003Publication date: February 12, 2004Inventors: Kazuo Asaka, Tomoaki Arakawa, Tsuyoshi Kagaya, Satoru Shinzaki, Hiromitsu Sato, Kenji Fukuda, Hirohisa Ogawa, Tatsuro Horie, Akihiro Okamura, Katsuaki Sato, Toshiyasu Komatsu, Youichi Nakahara
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Patent number: 6344273Abstract: The present invention provides a soft magnetic powder composite core for an electric apparatus produced with soft magnetic particles having electric insulating layers on the surfaces thereof, wherein said electric insulating layers are formed by mixing said soft magnetic particles with an insulating layer-forming solution which comprises a phosphating solution and a rust inhibitor, which is an organic compound containing at least one of nitrogen or sulfur having a lone pair of electrons suppressing the formation of iron oxide and surfactant, and drying the treated soft magnetic particles at a predetermined temperature. The soft magnetic powder composite core is excellent in iron loss and magnetic flux density.Type: GrantFiled: November 24, 1999Date of Patent: February 5, 2002Assignees: Hitachi, Ltd., Hitachi Powdered Metals Co., Ltd.Inventors: Yuichi Satsu, Hideaki Katayama, Yuzo Ito, Akio Takahashi, Noboru Baba, Chikara Tanaka, Kazuo Asaka, Chio Ishihara, Hiroaki Miyata, Kazuhiro Satou
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Patent number: 6120727Abstract: Disclosed is a method of manufacturing a machine component of sintered ferriferous composite comprising an outer part and an inner part which is fitted into a hole of the outer part. It has the steps of: preparing one of the outer part and the inner part as a green compact of ferriferous powdered metal and the other as one of a green compact of ferriferous powdered metal, a sintered compact of ferriferous powdered metal and a mass of ferriferous molten metal; inserting the inner part into the hole of the outer part; and sintering the outer part and the inner part to bond the outer part and the inner part. The outer part and the inner part are prepared to have a fitting clearance of approximately -100 to +5 .mu.m.Type: GrantFiled: September 15, 1999Date of Patent: September 19, 2000Assignee: Hitachi Powdered Metals Co., Ltd.Inventors: Kazuo Asaka, Tsuyoshi Kagaya, Masahiro Suzuki
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Patent number: D572660Type: GrantFiled: April 14, 2006Date of Patent: July 8, 2008Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Japan Servo Co., Ltd., Hitachi Powdered Metals Co., Ltd.Inventors: Yuji Enomoto, Motoya Ito, Kazumasa Ide, Masashi Kitamura, Ryoso Masaki, Katsuyuki Yamazaki, Shoji Ohiwa, Yasuaki Motegi, Kazuo Asaka, Chio Ishihara