Patents by Inventor Yoshihito Yoshizawa

Yoshihito Yoshizawa 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).

  • Patent number: 8298355
    Abstract: A soft magnetic alloy that in an FeCo nanocrystal soft magnetic material, exhibits a high saturation magnetic flux density of 1.85 T or more, and that ensures prolonged nozzle life and easy ribbon production; an amorphous alloy ribbon for use in production thereof; and magnetic parts utilizing the soft magnetic alloy. The soft magnetic alloy has the composition of the formula Fe100-x-y-aCoaCuxBy (in the formula, x, y and a each represent atomic % and satisfy the relationships 1<x?3, 10?y?20 and 10<a<25). At least part of the structure thereof consists of a crystal phase of 60 nm or less (not including 0) crystal grain diameter. The soft magnetic alloy has a saturation magnetic flux density of 1.85 T or more and a coercive force of 200 A/m or less.
    Type: Grant
    Filed: March 5, 2008
    Date of Patent: October 30, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yoshihito Yoshizawa, Motoki Ohta
  • Patent number: 8287666
    Abstract: A magnetic alloy having a composition represented by the general formula of Fe100-x-yCuxBy (atomic %), wherein x and y are numbers meeting the conditions of 0.1?x?3, and 10?y?20, or the general formula of Fe100-x-y-zCuxByXz (atomic %), wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0.1?x?3, 10?y?20, 0<z?10, and 10<y+z?24), the magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.
    Type: Grant
    Filed: December 2, 2010
    Date of Patent: October 16, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Publication number: 20120154084
    Abstract: A soft-magnetic, amorphous alloy ribbon produced by a rapid quenching method, having transverse lines of recesses formed on its surface by laser beams with predetermined longitudinal intervals, with a doughnut-shaped projection formed around each recess; doughnut-shaped projections having smooth surfaces substantially free from splashes of the alloy melted by the irradiation of laser beams, and a height t2 of 2 ?m or less; and a ratio t1/T of the depth t1 of the recesses to the thickness T of the ribbon being in a range of 0.025-0.18, thereby having low iron loss and low apparent power.
    Type: Application
    Filed: September 14, 2010
    Publication date: June 21, 2012
    Applicant: HITACHI METALS, LTD.
    Inventors: Yoshihito Yoshizawa, Naoki Ito, Shinichi Kazui, Makoto Sasaki
  • Patent number: 8182620
    Abstract: A magnetic alloy having a composition represented by the general formula of Fe100-x-yCuxBy(atomic %), wherein x and y are numbers meeting the conditions of 0.1?x?3, and 10?y?20, or the general formula of Fe100-x-y-zCuxByXz(atomic %), wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0.1?x?3, 10?y?20, 0<z?10, and 10<y+z?24), the magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.
    Type: Grant
    Filed: July 19, 2010
    Date of Patent: May 22, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Patent number: 8177923
    Abstract: A magnetic alloy having a composition represented by the general formula of Fe100-x-yCuxBy (atomic %), wherein x and y are numbers meeting the conditions of 0.1?x?3, and 10?y?20, or the general formula of Fe100-x-y-zCuxByXz (atomic %), wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0.1?x?3, 10?y?20, 0<z?10, and 10<y+z?24), the magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.
    Type: Grant
    Filed: September 19, 2006
    Date of Patent: May 15, 2012
    Assignee: Hitachi Metals, Ltd.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Patent number: 8083867
    Abstract: Even if produced from a broad amorphous alloy ribbon, a nano crystal soft magnetic alloy, a magnetic core made of a nano crystal soft magnetic alloy, and the amorphous alloy ribbon for a nano crystal soft magnetic alloys which has the excellent alternate magnetic property, the small dispersion, the excellent temporal stability in high temperature, the excellent mass productivity can be provided. An amorphous alloy ribbon, wherein the alloy composition is represented by Fe100-a-b-c-dMaSibBcCd (atomic %), 0<a?10, 0?b?20, 2?c?20, 0<d?2, 9?a+b+c+d?35, and an amorphous alloy ribbon consists of inevitable impurities, and said M is at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta, and W, and C concentration takes maximum value at 2-20 nm depth from the surface of said amorphous alloy with equivalent SiO2.
    Type: Grant
    Filed: September 21, 2006
    Date of Patent: December 27, 2011
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yoshihito Yoshizawa, Yuichi Ogawa
  • Publication number: 20110294012
    Abstract: It is an objective of the present invention to provide a lithium-ion rechargeable battery anode which can control the volume change of a primary particle of a negative-electrode active material other than a carbon-based material and that can prevent cracks due to stress caused by the volume change from occurring and extending. There is provided an anode for a lithium-ion rechargeable battery including a primary particle of a negative-electrode active material, a conductive material, and a binder, the negative-electrode active material including at least one of silicon and tin, and at least one element selected from elements that do not chemically react with lithium, in which holes are present both in an inner core region in the central region of the primary particle of the negative-electrode active material and in a periphery region that covers the inner core region.
    Type: Application
    Filed: May 27, 2011
    Publication date: December 1, 2011
    Inventors: Takashi Nakabayashi, Shin Takahashi, Motoki Ohta, Yoshihito Yoshizawa
  • Publication number: 20110272065
    Abstract: A method for producing a soft magnetic alloy ribbon having a composition represented by Fe100?x?y?zAxByXz, wherein A is Cu and/or Au, X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers (by atomic %) meeting the conditions of 0<x?5, 10?y?22, 1?z?10, and x+y+z?25, and comprising a matrix phase in which fine crystal grains having an average diameter of 60 nm or less are dispersed at a volume fraction of 50% or more, part of an oxide film formed on the surface being a layer having a lower B concentration than the average B concentration of the matrix phase; comprising the steps of (1) ejecting an alloy melt having the above composition onto a rotating cooling roll for quenching, to form a primary fine-crystalline alloy ribbon having a matrix phase, in which fine crystal nuclei having an average diameter of 30 nm or less are dispersed at a volume fraction of more than 0% and less than 30% in an amorphous phase; and then (2) annealing the pr
    Type: Application
    Filed: January 20, 2010
    Publication date: November 10, 2011
    Applicant: HITACHI METALS, LTD.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Patent number: 8021498
    Abstract: A magnetic core making use of an Fe-based amorphous alloy ribbon that simultaneously attains miniaturization and noise reduction through realization of high Bs; and an applied product making use of the same. There is provided a magnetic core making use of an Fe-based amorphous alloy ribbon, wherein the saturated magnetic flux density (Bs) of the Fe-based amorphous alloy ribbon is ?1.60 T and wherein the ratio between magnetic flux density at a core external magnetic field of 80 A/m (B80) and Bs of the Fe-based amorphous alloy ribbon, B80/Bs, is ?0.90.
    Type: Grant
    Filed: March 28, 2006
    Date of Patent: September 20, 2011
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yuichi Ogawa, Masamu Naoe, Yoshihito Yoshizawa
  • Patent number: 8007600
    Abstract: The invention provides a soft magnetic thin strip which contains nanoscale fine grains and exhibits a high saturation magnetic flux density and excellent soft magnetic characteristics; a process for production of the same; magnetic parts; and an amorphous thin strip to be used in the production. In the invention, an amorphous thin strip is used, which is represented by the composition formula: Fe100-x-y-zAxMyXz-aPa (wherein A is at least one element selected from between Cu and Au; M is at least one element selected from among Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn; X is at least one element selected from between B and Si; and x, y, z and a (in terms of atomic percentage) satisfy the relationships: 0.5?x?1.5, 0?y?2.5, 10?z?23, and 0.35?a?10 respectively) and permits 180° bending.
    Type: Grant
    Filed: April 24, 2008
    Date of Patent: August 30, 2011
    Assignee: Hitachi Metals, Ltd.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Publication number: 20110203705
    Abstract: This method of producing an amorphous transformer for electric power supply comprises forming and shaping an iron core by laminating amorphous alloy thin bands and forming a winding, subjecting the iron core, after forming and shaping, to an annealing treatment in which a temperature of a center portion of the iron core during annealing is 300 to 340° C. and a holding time is not less than 0.5 hr, and applying a magnetic field having a strength of not less than 800 A/m to the iron core while subjecting the iron core, after forming and shaping, to the annealing treatment.
    Type: Application
    Filed: May 5, 2011
    Publication date: August 25, 2011
    Inventors: Kazuyuki FUKUI, Koji Yamashita, Yuichi Ogawa, Masamu Naoe, Yoshihito Yoshizawa
  • Publication number: 20110108167
    Abstract: A magnetic alloy having a composition represented by the general formula of Fe100-x-yCuxBy (atomic %), wherein x and y are numbers meeting the conditions of 0.1?x?3, and 10?y?20, or the general formula of Fe100-x-y-xCuxByZz (atomic %), wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0.1?x?3, 10?y?20, 0<z?10, and 10<y+z?24), the magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.
    Type: Application
    Filed: July 19, 2010
    Publication date: May 12, 2011
    Applicant: HITACHI METALS, LTD.
    Inventors: Motoki OHTA, Yoshihito YOSHIZAWA
  • Patent number: 7935196
    Abstract: A soft magnetic ribbon that especially in a relatively low magnetic field region of 500 A/m or less, is high in the squareness of magnetic flux density-magnetization curve. There is disclosed a soft magnetic ribbon of 100 ?m or less thickness comprising a parent phase structure in which by volume ratio, 30% or more of crystal grains of 60 nm or less (not including 0) crystal grain diameter are dispersed in an amorphous phase and comprising an amorphous layer disposed on the surface side of the parent phase structure. Preferably, the soft magnetic ribbon is represented by the composition formula Fe100-x-yCuxXy (wherein X is at least one element selected from among B, Si, S, C, P, Al, Ge, Ga and Be), in which the atomic percents (%) satisfy the relationships 0<x?5 and 10?y?24.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: May 3, 2011
    Assignee: Hitachi Metals, Ltd.
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Publication number: 20110085931
    Abstract: A magnetic alloy having a composition represented by the general formula of Fe100-x-yCuxBy (atomic %), wherein x and y are numbers meeting the conditions of 0.1?x?3, and 10?y?20, or the general formula of Fe100-x-y-zCuxByXz (atomic %), wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0.1?x?3, 10?y?20, 0<z?10, and 10<y+z?24), the magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.
    Type: Application
    Filed: December 2, 2010
    Publication date: April 14, 2011
    Applicant: HITACHI METALS, LTD.
    Inventors: Motoki OHTA, Yoshihito YOSHIZAWA
  • Patent number: 7837807
    Abstract: A magnetic core for a current transformer, and a current transformer and a watt hour meter used thereof, which is preferred the detection of a alternate current with a large asymmetrical waveform and a alternate current which a direct current is superimposed are realized. A magnetic core for a current transformer comprising the composition represented by the general formula: Fe100-x-a-y-cMxCuaM?yX?c (atomic %), wherein M is at least one element selected from Co and Ni, M? is at least one element selected from V, Ti, Zr, Nb, Mo, Hf, Ta, X? is at least one element selected from Si and B, and x, a, y, and c meets the composition of 3?x?50, 0.1?a?3, 1?y?10, 2?c?30, and also 7?y+c?30, and an alloy comprising a crystal grain consisting of at least a part or all of the composition with a mean particle size of less than or equal to 50 nm.
    Type: Grant
    Filed: March 19, 2007
    Date of Patent: November 23, 2010
    Assignee: Hitachi Metals, Ltd.
    Inventor: Yoshihito Yoshizawa
  • Publication number: 20100230010
    Abstract: Disclosed are a thin strip of an amorphous alloy having excellent workability, a nanocrystalline soft magnetic alloy which can stably provide good magnetic properties, and a magnetic core using the nanocrystalline soft magnetic alloy. The thin strip of an amorphous alloy is characterized in that the thin strip is formed of an alloy having a composition represented by Fe10-a-b-c-dMaSibBcCud (atomic %), wherein 0?a?10, 0?b?20, 4?c?20, 0.1?d?3, and 9?a+b+c?35, and containing unavoidable impurities, and, in the composition, M represents at least one element selected from Ti, V, Zr, Nb, Mo, Hf, Ta, and W, a Cu segregated part is present, on the surface side of the thin strip of the amorphous alloy, in which Cu is segregated at a higher concentration than the Cu concentration in the outermost surface part of the thin strip of the amorphous alloy, and the highest Cu concentration in the Cu segregated part is not more than 4 atomic %.
    Type: Application
    Filed: March 30, 2009
    Publication date: September 16, 2010
    Inventors: Yoshihito Yoshizawa, Motoki Ohta
  • Publication number: 20100108196
    Abstract: A soft magnetic ribbon that especially in a relatively low magnetic field region of 500 A/m or less, is high in the squareness of magnetic flux density-magnetization curve. There is disclosed a soft magnetic ribbon of 100 ?m or less thickness comprising a parent phase structure in which by volume ratio, 30% or more of crystal grains of 60 nm or less (not including 0) crystal grain diameter are dispersed in an amorphous phase and comprising an amorphous layer disposed on the surface side of the parent phase structure. Preferably, the soft magnetic ribbon is represented by the composition formula Fe100-x-yCuxXy (wherein X is at least one element selected from among B, Si, S, C, P, Al, Ge, Ga and Be), in which the atomic percents (%) satisfy the relationships 0<x?5 and 10?y?24.
    Type: Application
    Filed: March 4, 2008
    Publication date: May 6, 2010
    Applicant: Hitachi Metals, LTD
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Publication number: 20100098576
    Abstract: An iron-based soft magnetic alloy which is for use in various transformers, various choke coils, noise suppression measures, power supply parts, laser power supplies, pulsed-power magnetic parts for accelerators, various motors, various generators, magnetic shields, antennas, sensors, etc.; a thin ribbon of an amorphous alloy for producing the magnetic alloy; and a magnetic part comprising the magnetic alloy. The magnetic alloy comprises, in terms of at. %, copper in an amount (x) satisfying 0.1?x?3, boron in an amount (y) satisfying 10?y?20, and iron and impurities as the remainder. It contains, in terms of mass %, the following impurities: up to 0.01% aluminum, 0.001-0.05% sulfur, 0.01-0.5% manganese, 0.001-0.1% nitrogen, and up to 0.1% oxygen. The magnetic alloy has a structure at least part of which comprises a crystal phase having a crystal grain diameter of 60 nm or smaller (excluding 0).
    Type: Application
    Filed: March 12, 2008
    Publication date: April 22, 2010
    Applicant: Hitachi Metals, Ltd.
    Inventors: Yoshihito Yoshizawa, Motoki Ohta
  • Publication number: 20100084056
    Abstract: The invention provides a soft magnetic thin strip which contains nanoscale fine grains and exhibits a high saturation magnetic flux density and excellent soft magnetic characteristics; a process for production of the same; magnetic parts; and an amorphous thin strip to be used in the production. In the invention, an amorphous thin strip is used, which is represented by the composition formula: Fe100-x-y-zAxMyXz-aPa (wherein A is at least one element selected from between Cu and Au; M is at least one element selected from among Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn; X is at least one element selected from between B and Si; and x, y, z and a (in terms of atomic percentage) satisfy the relationships: 0.5?x?1.5, 0?y?2.5, 10?z?23, and 0.35?a?10 respectively) and permits 180° bending.
    Type: Application
    Filed: April 25, 2007
    Publication date: April 8, 2010
    Applicant: Hitachi Metals, Ltd
    Inventors: Motoki Ohta, Yoshihito Yoshizawa
  • Publication number: 20100040503
    Abstract: A soft magnetic alloy that in an FeCo nanocrystal soft magnetic material, exhibits a high saturation magnetic flux density of 1.85 T or more, and that ensures prolonged nozzle life and easy ribbon production; an amorphous alloy ribbon for use in production thereof; and magnetic parts utilizing the soft magnetic alloy. The soft magnetic alloy has the composition of the formula Fe100-x-y-aCoaCuxBy (in the formula, x, y and a each represent atomic % and satisfy the relationships 1<x?3, 10?y?20 and 10<a<25). At least part of the structure thereof consists of a crystal phase of 60 nm or less (not including 0) crystal grain diameter. The soft magnetic alloy has a saturation magnetic flux density of 1.85 T or more and a coercive force of 200 A/m or less.
    Type: Application
    Filed: March 5, 2008
    Publication date: February 18, 2010
    Applicant: HITACHI METALS, LTD.
    Inventors: Yoshihito Yoshizawa, Motoki Ohta