Patents by Inventor Nobuaki Akagi
Nobuaki Akagi 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: 11241736Abstract: The present invention relates to a powder mixture for iron-based powder metallurgy which is obtained by mixing an iron-based powder and at least one kind of powders selected from the group consisting of a Ca—Al—Si-based composite oxide powder and a Ca—Mg—Si-based composite oxide powder, in which with a peak height of a main phase exhibiting the highest peak intensity by X-ray diffraction as 100, the composite oxide powder has a relative height of 40% or less, with respect to the main phase, of a peak height of a second phase having the second highest peak intensity.Type: GrantFiled: November 1, 2017Date of Patent: February 8, 2022Assignee: KABUSHIKI KAISHA KOBE SEIKO SHO (Kobe Steel, Ltd.)Inventor: Nobuaki Akagi
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Patent number: 10500638Abstract: One aspect of the present invention is a lubricant to be incorporated into a powder metallurgical mixed powder containing an iron-based powder. The lubricant includes a flaky organic material having an average particle diameter of from 0.1 ?m to less than 3 ?m. Another aspect of the present invention is a powder metallurgical mixed powder which contains an iron-based powder and the lubricant. Yet another aspect of the present invention is a method for producing a sintered compact. The method includes the step of mixing materials to give a powder metallurgical mixed powder containing an iron-based powder and the lubricant. The powder metallurgical mixed powder is compacted using a die to give a powder compact. The powder compact is sintered to give a sintered compact.Type: GrantFiled: December 1, 2015Date of Patent: December 10, 2019Assignee: Kobe Steel, Ltd.Inventors: Yoshihiro Ito, Eiichiro Yoshikawa, Nobuaki Akagi, Yuji Taniguchi, Mitsuhiro Sato
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Publication number: 20190283126Abstract: The present invention relates to a powder mixture for iron-based powder metallurgy which is obtained by mixing an iron-based powder and at least one kind of powders selected from the group consisting of a Ca—Al—Si-based composite oxide powder and a Ca—Mg—Si-based composite oxide powder, in which with a peak height of a main phase exhibiting the highest peak intensity by X-ray diffraction as 100, the composite oxide powder has a relative height of 40% or less, with respect to the main phase, of a peak height of a second phase having the second highest peak intensity.Type: ApplicationFiled: November 1, 2017Publication date: September 19, 2019Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (Kobe Steel, Ltd.)Inventor: Nobuaki AKAGI
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Patent number: 10256019Abstract: An iron-based soft magnetic powder for dust core having a high magnetic flux density, maintaining high electric insulation even after annealing, and more excellent in the mechanical strength in which a coating film having a phosphate conversion coating film is formed on the surface thereof and the peak height for the absorption of hydroxyl groups formed at 3700 cm?1 to 2500 cm?1 is 0.04 or more being indicated by absorbance when the coating film is analyzed by infrared diffuse reflectance spectroscopy.Type: GrantFiled: August 5, 2015Date of Patent: April 9, 2019Assignee: KOBE STEEL, LTD.Inventors: Takeshi Ohwaki, Hiroyuki Mitani, Hirofumi Hojo, Kasumi Yanagisawa, Nobuaki Akagi
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Patent number: 10240032Abstract: The present invention provides a binder which has excellent effect on suppression of segregation or dust emission, while exhibiting excellent fluidity both at ordinary temperatures and at high temperatures. The present invention is a binder which is blended for use in a mixed powder for powder metallurgy, said mixed powder containing an iron-based powder and an auxiliary starting material powder. This binder is characterized by being composed of one or more polymers that are selected from among butene polymers having a melting point of from 50° C. to 85° C. (inclusive) and a heated melt fluidity at 190° C. of from 2.0 g/10 minutes to 3.6 g/10 minutes (inclusive) and methacrylic acid polymers having a weight average molecular weight of 1,000,000 or less.Type: GrantFiled: February 17, 2014Date of Patent: March 26, 2019Assignee: Kobe Steel, Ltd.Inventors: Yoshihiro Ito, Eiichiro Yoshikawa, Nobuaki Akagi, Mitsuhiro Sato
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Publication number: 20180141117Abstract: The mixed powder for iron-based powder metallurgy of the present invention comprises an iron-based powder and a CaS raw material powder containing one or more selected from the group consisting of calcium sulfate anhydrite III, calcium sulfate anhydrite II, calcium sulfate dihydrate, calcium sulfide, and calcium sulfate hemihydrate. The CaS raw material powder is coated with at least one selected from a lubricant and a binder.Type: ApplicationFiled: April 27, 2016Publication date: May 24, 2018Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (Kobe Steel, Ltd.)Inventor: Nobuaki AKAGI
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Publication number: 20180126454Abstract: The mixed powder for iron-based powder metallurgy of the present invention comprises: at least one ternary oxide selected from the group consisting of Ca—Al—Si oxides and Ca—Mg—Si oxides, and at least one binary oxide selected from the group consisting of Ca—Al oxides and Ca—Si oxides. The ternary oxide and the binary oxide are contained in a sum weight of 0.025 wt % or more to 0.3 wt % or less.Type: ApplicationFiled: April 27, 2016Publication date: May 10, 2018Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventor: Nobuaki AKAGI
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Publication number: 20180104739Abstract: The mixed powder for iron-based powder metallurgy of the present invention comprises a powder containing calcium sulfate anhydrite II such that the CaS weight ratio after sintering is 0.01 wt % or more to 0.1 wt % or less. The powder containing calcium sulfate anhydrite II preferably has a volume-average particle size of 0.1 ?m or more to 60 ?m or less and preferably additionally contains one or more ternary oxides selected from the group consisting of Ca—Al—Si oxides and Ca—Mg—Si oxides. The weight ratio of the ternary oxides and CaS after the sintering is preferably 3:7 to 9:1.Type: ApplicationFiled: April 27, 2016Publication date: April 19, 2018Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventor: Nobuaki AKAGI
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Publication number: 20170304893Abstract: One aspect of the present invention is a lubricant to be incorporated into a powder metallurgical mixed powder containing an iron-based powder. The lubricant includes a flaky organic material having an average particle diameter of from 0.1 ?m to less than 3 ?m. Another aspect of the present invention is a powder metallurgical mixed powder which contains an iron-based powder and the lubricant. Yet another aspect of the present invention is a method for producing a sintered compact. The method includes the step of mixing materials to give a powder metallurgical mixed powder containing an iron-based powder and the lubricant. The powder metallurgical mixed powder is compacted using a die to give a powder compact. The powder compact is sintered to give a sintered compact.Type: ApplicationFiled: December 1, 2015Publication date: October 26, 2017Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Yoshihiro ITO, Eiichiro Yoshikawa, Nobuaki AKAGI, Yuji TANIGUCHI, Mitsuhiro SATO
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Publication number: 20170266723Abstract: An objective of the present invention is to provide a mixed powder for powder metallurgy that makes it possible to improve mold-filling ability and reduce spread in weight of molded bodies. The mixed powder for powder metallurgy according to the present invention is obtained by mixing a graphite powder with an average particle diameter D50 of 1.0 ?m or more to 3.0 ?m or less and D90 of 10 ?m or less, without adding a binder, with an iron-based powder, while applying a sheer force. The thus obtained mixed powder for powder metallurgy according to the present invention is characterized by including the iron-based powder and the graphite powder present so as to be collected in concave portions of the iron-based powder.Type: ApplicationFiled: May 14, 2015Publication date: September 21, 2017Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)Inventors: Mitsuhiro SATO, Nobuaki AKAGI, Hironori SUZUKI
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Patent number: 9275779Abstract: Provided is an iron-based soft magnetic powder for dust core having a less coercive force, which is obtained by specifying the amount of inclusions in the iron-based powder for dust core, and at the same time, capable of decreasing the coercive force of a dust core produced using the iron-based soft magnetic powder. The iron-based soft magnetic powder for dust core is characterized by that when the cross-section of the iron-based soft magnetic powder particle is observed with a scanning electron microscope, the number of inclusions having an equivalent circle diameter from 0.1 to 3 ?m is 1×104 pieces/mm2 or less and the number of inclusions having an equivalent circle diameter exceeding 3 ?m is 10 pieces/mm2 or less.Type: GrantFiled: November 29, 2011Date of Patent: March 1, 2016Assignee: Kobe Steel, Ltd.Inventors: Hirofumi Hojo, Masamichi Chiba, Hiroyuki Mitani, Nobuaki Akagi, Tomotsuna Kamijo
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Publication number: 20150361255Abstract: The present invention provides a binder which has excellent effect on suppression of segregation or dust emission, while exhibiting excellent fluidity both at ordinary temperatures and at high temperatures. The present invention is a binder which is blended for use in a mixed powder for powder metallurgy, said mixed powder containing an iron-based powder and an auxiliary starting material powder. This binder is characterized by being composed of one or more polymers that are selected from among butene polymers having a melting point of from 50° C. to 85° C. (inclusive) and a heated melt fluidity at 190° C. of from 2.0 g/10 minutes to 3.6 g/10 minutes (inclusive) and methacrylic acid polymers having a weight average molecular weight of 1,000,000 or less.Type: ApplicationFiled: February 17, 2014Publication date: December 17, 2015Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Yoshihiro ITO, Eiichiro YOSHIKAWA, Nobuaki AKAGI, Mitsuhiro SATO
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Publication number: 20150340138Abstract: An iron-based soft magnetic powder for dust core having a high magnetic flux density, maintaining high electric insulation even after annealing, and more excellent in the mechanical strength in which a coating film having a phosphate conversion coating film is formed on the surface thereof and the peak height for the absorption of hydroxyl groups formed at 3700 cm?1 to 2500 cm?1 is 0.04 or more being indicated by absorbance when the coating film is analyzed by infrared diffuse reflectance spectroscopy.Type: ApplicationFiled: August 5, 2015Publication date: November 26, 2015Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)Inventors: Takeshi OHWAKI, Hiroyuki MITANI, Hirofumi HOJO, Kasumi YANAGISAWA, Nobuaki AKAGI
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Patent number: 8445105Abstract: An iron-based magnetic powder for dust cores has layers of phosphoric acid-based film and silicone resin film sequentially formed on the surface thereof. The phosphoric acid-based film contains at least one element selected from the group consisting of Co, Na, S, Si, and W. The iron-based powder effectively keeps insulation among iron powder particles, excels in mechanical strength even though the amount of insulating material is reduced due to achieve high-density forming, and exhibits good thermal stability necessary for electrical insulating properties even after high-temperature heat treatment.Type: GrantFiled: August 2, 2007Date of Patent: May 21, 2013Assignee: Kobe Steel, Ltd.Inventors: Hiroyuki Mitani, Nobuaki Akagi, Hirofumi Houjou, Chio Ishihara, Makoto Iwakiri, Sohei Yamada, Yasukumi Mochimizo
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Patent number: 8409707Abstract: The invention relates to an iron-based soft magnetic powder for a dust core, wherein a film comprising Fe and Co, a phosphoric acid-based chemical conversion film and a silicone resin film are formed in this order on the surface of an iron-based soft magnetic powder, and to a dust core obtained by molding the iron-based soft magnetic powder for a dust core. The invention also relates to an iron-based soft magnetic powder for a dust core formed by coating the surface of an iron-based soft magnetic powder with an insulating film, wherein the powder has a particle diameter of from 45 ?m to 180 ?m, the insulating film is composed of two layers in which a lower layer composed of a phosphoric acid-based chemical conversion film and an upper layer composed of a silicone resin film, and each of the films has a thickness of from 100 nm to 280 nm, and to a dust core obtained by molding the iron-based soft magnetic powder for a dust core.Type: GrantFiled: July 2, 2008Date of Patent: April 2, 2013Assignee: Kobe Steel, Ltd.Inventors: Hiroyuki Mitani, Nobuaki Akagi, Hirofumi Houjou
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Patent number: 8236087Abstract: The present invention relates to an iron-base powder for a powder core, wherein when cross-sections of at least 50 iron-base powders are observed and a crystal grain size distribution containing at least a maximum crystal grain size is determined by measuring a crystal grain size of each iron-base powder, 70% or more of the measured crystal grains are a crystal grain having a crystal grain size of 50 ?m or more. According to the iron-base powder of the invention, a coercivity of the powder core can be made small and a hysteresis loss can be reduced.Type: GrantFiled: September 11, 2007Date of Patent: August 7, 2012Assignees: Kobe Steel, Ltd., Hitachi Powdered Metals Co., Ltd.Inventors: Hiroyuki Mitani, Nobuaki Akagi, Hirofumi Houjou, Chio Ishihara, Makoto Iwakiri, Sohei Yamada, Yasukuni Mochimizo
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Publication number: 20120164453Abstract: Provided is an iron-based soft magnetic powder for dust core having a less coercive force, which is obtained by specifying the amount of inclusions in the iron-based powder for dust core, and at the same time, capable of decreasing the coercive force of a dust core produced using the iron-based soft magnetic powder. The iron-based soft magnetic powder for dust core is characterized by that when the cross-section of the iron-based soft magnetic powder particle is observed with a scanning electron microscope, the number of inclusions having an equivalent circle diameter from 0.1 to 3 ?m is 1×104 pieces/mm2 or less and the number of inclusions having an equivalent circle diameter exceeding 3 ?m is 10 pieces/mm2 or less.Type: ApplicationFiled: November 29, 2011Publication date: June 28, 2012Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Hirofumi HOJO, Masamichi Chiba, Hiroyuki Mitani, Nobuaki Akagi, Tomotsuna Kamijo
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Publication number: 20100212455Abstract: An iron-based soft magnetic powder for dust core having a high magnetic flux density, maintaining high electric insulation even after annealing, and more excellent in the mechanical strength in which a coating film having a phosphate conversion coating film is formed on the surface thereof and the peak height for the absorption of hydroxyl groups formed at 3700 cm?1 to 2500 cm?1 is 0.04 or more being indicated by absorbance when the coating film is analyzed by infrared diffuse reflectance spectroscopy.Type: ApplicationFiled: December 29, 2009Publication date: August 26, 2010Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel Ltd)Inventors: Takeshi OHWAKI, Hiroyuki Mitani, Hirofumi Hojo, Kasumi Yanagisawa, Nobuaki Akagi
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Publication number: 20100188179Abstract: The invention relates to an iron-based soft magnetic powder for a dust core, wherein a film comprising Fe and Co, a phosphoric acid-based chemical conversion film and a silicone resin film are formed in this order on the surface of an iron-based soft magnetic powder, and to a dust core obtained by molding the iron-based soft magnetic powder for a dust core. The invention also relates to an iron-based soft magnetic powder for a dust core formed by coating the surface of an iron-based soft magnetic powder with an insulating film, wherein the powder has a particle diameter of from 45 ?m to 180 ?m, the insulating film is composed of two layers in which a lower layer composed of a phosphoric acid-based chemical conversion film and an upper layer composed of a silicone resin film, and each of the films has a thickness of from 100 nm to 280 nm, and to a dust core obtained by molding the iron-based soft magnetic powder for a dust core.Type: ApplicationFiled: July 2, 2008Publication date: July 29, 2010Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)Inventors: Hiroyuki Mitani, Nobuaki Akagi, Hirofumi Houjou
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Publication number: 20100051851Abstract: Disclosed herein is an iron powder for dust cores which effectively keeps insulation among iron powder particles and excels in mechanical strength even though the amount of insulating material is reduced to achieve high-density forming and which also exhibits good thermal stability necessary for electrical insulating properties even after heat treatment at high temperatures. The iron-based magnetic powder has layers of phosphoric acid-based film and silicone resin film sequentially formed on the surface thereof, said phosphoric acid-based film containing at least one element selected from the group consisting of Co, Na, S, Si, and W.Type: ApplicationFiled: August 2, 2007Publication date: March 4, 2010Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)Inventors: Hiroyuki Mitani, Nobuaki Akagi, Hirofumi Houjou, Chio Ishihara, Makoto Iwakiri, Sohei Yamada, Yasukumi Mochimizo